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Sample records for conventional penetrating keratoplasty

  1. Comparison of penetrating keratoplasty performed with a femtosecond laser zig-zag incision versus conventional blade trephination.

    PubMed

    Farid, Marjan; Steinert, Roger F; Gaster, Ronald N; Chamberlain, Winston; Lin, Amy

    2009-09-01

    To evaluate visual outcomes and astigmatism in patients who underwent penetrating keratoplasty (PK) with 2 different incision techniques. Retrospective comparison of a consecutive surgical series. Fifty-seven consecutive patients who underwent PK at the University of California, Irvine, academic referral practice. A comparison of 49 eyes of 43 patients that underwent femtosecond laser zig-zag incision pattern PK versus 17 eyes of 14 patients that underwent conventional Barron suction trephination PK performed contemporaneously. All PKs were closed with an identical, 24-bite running nylon suture technique. Topographically determined astigmatism, best spectacle-corrected visual acuity (BSCVA), and recovery of full visual potential. The postoperative follow-up ranged from 1 to 12 months. There was a significant difference in average astigmatism between the groups at postoperative month 1 (P = 0.013) and 3 (P = 0.018). By month 3, the average astigmatism was 3 diopters (D) in the zig-zag group and 4.46 D in the conventional group. Of the patients with normal macular and optic nerve function (n(ZZ) = 32; n(con) = 14), a significant difference in BSCVA was seen at month 1 (P = 0.0003) and month 3 (P = 0.006) with 81% of the zig-zag group versus 45% of the conventional group achieving BSCVA of > or =20/40 by month 3 (P = 0.03). The femtosecond laser generated zig-zag-shaped incision results in a more rapid recovery of BSCVA and induces less astigmatism compared with conventional blade trephination PK. Proprietary commercial disclosure may be found after the references.

  2. Microbial Keratitis After Penetrating Keratoplasty.

    PubMed

    Sun, Jen-Pin; Chen, Wei-Li; Huang, Jehn-Yu; Hou, Yu-Chih; Wang, I-Jong; Hu, Fung-Rong

    2017-06-01

    To report the incidence, microbiological profile, graft survival, and determining factors of microbial keratitis after penetrating keratoplasty (PK). Observational case series. The study involved 51 patients (52 eyes) who were treated at a single tertiary referral center during a 10-year period. Retrospective chart review included medical records of all patients diagnosed with microbial keratitis after penetrating keratoplasty at the National Taiwan University Hospital between January 2000 and December 2009. The main outcome measures were incidence of graft infection, microbial profile, and graft survival status. There were 871 PKs performed and 67 episodes in 52 eyes of culture-positive microbial keratitis during the study period. There were 32 infectious episodes (47.8%) in the first year post-PK and 35 episodes (52.2%) after the first year post-PK. Forty-four gram-positive bacterial isolates (57.9%), 17 gram-negative bacterial isolates (22.4%), and 15 fungal isolates (19.7%) were found. Twenty-three (34.3%) grafts remained clear after the infection episode with a mean follow-up of 1127 days (range, 25-3962 days). There was no difference in graft survival rate regarding the original indication of PK or offending pathogen. Suture-related infection was associated with decreased risk of graft failure (P = .02), while the factor associated with increased risk of graft failure was usage of antiglaucoma agents (P = .01). Infectious keratitis after penetrating keratoplasty leads to a high graft failure rate. Such complications can occur before or after the first year post-PK. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Surface keratopathy after penetrating keratoplasty.

    PubMed

    Feiz, V; Mannis, M J; Kandavel, G; McCarthy, M; Izquierdo, L; Eckert, M; Schwab, I R; Torabian, S; Wang, J L; Wang, W

    2001-01-01

    To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium. Prospective cohort study. We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy. Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also associated with an increased

  4. Surface keratopathy after penetrating keratoplasty.

    PubMed Central

    Feiz, V; Mannis, M J; Kandavel, G; McCarthy, M; Izquierdo, L; Eckert, M; Schwab, I R; Torabian, S; Wang, J L; Wang, W

    2001-01-01

    PURPOSE: To determine the type and prevalence of epithelial abnormalities in the intermediate postoperative period after penetrating keratoplasty and to define the donor and recipient variables that influence the status of the graft epithelium. DESIGN: Prospective cohort study. METHODS: We prospectively followed the clinical course of 80 patients after penetrating keratoplasty. We monitored the status of the corneal epithelium for 3 months after surgery using slit-lamp biomicroscopy and fluorescein staining of the epithelium. Donor characteristics, recipient preoperative and postoperative variables, and postoperative medications were recorded. Epithelial abnormalities were analyzed against these variables by using univariate and combined statistical models to determine the impact of each variable on postoperative epithelial pathology. Main outcome measures included punctate keratopathy, macro-epithelial defects, hurricane keratopathy, rim defects, and filamentary keratopathy. RESULTS: Sixty-three percent of all patient visits demonstrated punctate epithelial keratopathy (PEK). Hurricane keratopathy (51%) and filamentary keratopathy (14%) constituted the next most commonly observed abnormalities. Older recipient age and the use of topical antibiotics were associated with a higher prevalence of punctate epithelial keratopathy. The odds ratio (OR) for a 1-year increase in age is 1.0276 (95% CI, 1.1013-1.0442), and the OR for using topical antibiotics is 6.9028 (95% CI, 3.1506-15.1239). Use of topical ofloxacin and increased time after surgery were associated with lower prevalence of punctate keratopathy; ORs were 0.9806 (95% CI, 0.9736-0.9876) and 0.3662 (95% CI, 0.1688-0.7943), respectively. Decreased corneal sensation and the presence of anterior blepharitis preoperatively were associated with an increase in hurricane keratopathy; ORs were 8.8265 (CI, 2.3837-32.6835) and 3.2815 (CI, 1.7388-6.1931), respectively. Total storage time for the donor material was also

  5. Post-penetrating keratoplasty glaucoma

    PubMed Central

    Aggarwal, Anand; Minudath, KB; Vanathi, M; Choudhary, Sunil; Gupta, Viney; Sihota, Ramanjit; Panda, Anita

    2008-01-01

    Post-penetrating keratoplasty (post-PK) glaucoma is an important cause of irreversible visual loss and graft failure. The etiology for this disorder is multifactorial, and with the use of new diagnostic equipment, it is now possible to elucidate the exact pathophysiology of this condition. A clear understanding of the various mechanisms that operate during different time frames following PK is essential to chalk out the appropriate management algorithms. The various issues with regard to its management, including the putative risk factors, intraocular pressure (IOP) assessment post-PK, difficulties in monitoring with regard to the visual fields and optic nerve evaluation, are discussed. A step-wise approach to management starting from the medical management to surgery with and without metabolites and the various cycloablative procedures in cases of failed filtering procedures and excessive perilimbal scarring is presented. Finally, the important issue of minimizing the incidence of glaucoma following PK, especially through the use of oversized grafts and iris tightening procedures in the form of concomitant iridoplasty are emphasized. It is important to weigh the risk-benefit ratio of any modality used in the treatment of this condition as procedures aimed at IOP reduction, namely trabeculectomy with antimetabolites, and glaucoma drainage devices can trigger graft rejection, whereas cyclodestructive procedures can not only cause graft failure but also precipitate phthisis bulbi. Watchful expectancy and optimal time of intervention can salvage both graft and vision in this challenging condition. PMID:18579984

  6. Excimer laser mushroom penetrating keratoplasty: new technique.

    PubMed

    Della Valle, Vincenzo; Bonci, Paolo

    2014-01-01

    To evaluate retrospectively the outcomes of 15 consecutive mushroom-shaped penetrating keratoplasties performed by using excimer laser for both the recipient bed and the fresh donor corneas. Fifteen eyes of 14 patients who underwent excimer laser mushroom-shaped penetrating keratoplasty from October 13, 2010, to October 14, 2011, were included in our retrospective study. Eight were men and 6 were women, with a mean age of 31.45 ± 6.52 (range 27-65) years. Eleven (73.3%) had postinfective central deep corneal scar; 4 (26.7%) had severe keratoconus with Descemet opacity. The mean follow-up was 11.9 ± 2.7 months. The mean preoperative best-corrected visual acuity (BCVA) was 0.15 ± 0.16; the postoperative BCVA was 0.69 ± 0.24 after 12 months with a mean refractive astigmatism of 1.8 ± 1.1 D. The mean preoperative endothelial cell count of the donor corneas was 2297.0 ± 189.7 cells/mm²; after 12 months, it was 1906.5 ± 165.8 with a decrease of 17.0%. No intraoperative complications occurred. Our results showed that excimer laser mushroom penetrating keratoplasty is safe. Furthermore, it does not appear to influence the visual outcomes of the penetrating keratoplasty surgery. This technique is useful for those who use an excimer laser.

  7. Deep anterior lamellar keratoplasty versus penetrating keratoplasty for treating keratoconus.

    PubMed

    Keane, Miriam; Coster, Douglas; Ziaei, Mohammed; Williams, Keryn

    2014-07-22

    Keratoconus is an ectatic (weakening) disease of the cornea, which is the clear surface at the front of the eye. Approximately 10% to 15% of patients diagnosed with keratoconus require corneal transplantation. This may be full-thickness (penetrating) or partial-thickness (lamellar). To compare visual outcomes after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty for keratoconus, and to compare additional outcomes relating to factors which may contribute to poor visual outcomes (e.g. astigmatism, graft rejection and failure). We searched a number of electronic databases including CENTRAL, PubMed and EMBASE without using any date or language restrictions. We last searched the electronic databases on 31 October 2013. We also handsearched the proceedings of several international ophthalmic conferences. We included all randomised controlled trials (RCTs) comparing the outcomes of DALK and penetrating keratoplasty in the treatment of keratoconus. Two authors assessed trial quality and extracted data independently. For dichotomous data (graft failure, rejection, achievement of functional vision) results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). For continuous data (postoperative best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), keratometric astigmatism and spherical equivalent) results were expressed as mean differences (MDs) and 95% CIs. We identified two completed studies, with a total of 111 participants (n = 30 and n = 81), both conducted in Iran, that met our inclusion criteria. Participants had moderate to severe keratoconus pre-operatively and were randomly allocated to receive either DALK or penetrating keratoplasty. Only one eye of each participant was treated as part of the trials. The smaller study had 12 month follow-up data for all participants. For the larger study, four DALK surgeries had to be abandoned due to technical failure and visual and refractive outcomes were not measured in

  8. Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy

    PubMed Central

    Nanavaty, Mayank A; Wang, Xue; Shortt, Alex J

    2014-01-01

    Background Fuchs endothelial dystrophy (FED) is a condition in which there is premature degeneration of corneal endothelial cells. When the number of endothelial cells is reduced to a significant degree, fluid begins to accumulate within the cornea. As a result, the cornea loses its transparency and the individual suffers a reduction in vision. The only successful surgical treatment for this condition is replacement of part or all of the cornea with healthy tissue from a donor. The established procedure, penetrating keratoplasty (PKP), has been used for many years and its safety and efficacy are well known. Endothelial keratoplasty (EK) techniques are relatively new surgical procedures and their safety and efficacy relative to PKP are uncertain. Objectives The objective of this review was to compare the benefits and complications related to two surgical methods (EK and PKP) of replacing the diseased endothelial layer of the cornea with a healthy layer in people with FED. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2014, Issue 1), MEDLINE (January 1950 to January 2014), EMBASE (January 1980 to January 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to January 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 27 January 2014. Selection criteria We included all randomised controlled trials (RCTs) comparing EK versus PKP for people (of any age and gender) who had been clinically diagnosed with FED. Data collection and analysis Two authors independently screened the search results, assessed trial quality and extracted data using the standard methodological procedures expected by The Cochrane Collaboration. Main results We included three

  9. Descemet stripping automated endothelial keratoplasty after failed penetrating keratoplasty.

    PubMed

    Jangi, Anisha A; Ritterband, David C; Wu, Elaine I; Mehta, Veeral V; Koplin, Richard S; Seedor, John A

    2012-10-01

    To report the rate of graft dislocation, surgical anatomic success, and postsurgical complications associated with Descemet stripping automated endothelial keratoplasty (DSAEK) after previous primary failed penetrating keratoplasty (PK). Institutional review board-approved, single-center, retrospective chart review study of 30 eyes of 30 patients with prior failed PK who underwent DSAEK with a minimum of 3 months follow-up. Primary outcomes measured included rates of anatomic success and failure, postoperative complications, lenticle size, visual acuity, intraocular pressure change, and a report of external factors that may affect success. Thirty eyes of 30 patients were identified. The primary dislocation rate was 16.7%. Five primary DSAEKs detached; 1 was successfully rebubbled in the office, 2 had repeat successful DSAEKs, and 2 failed on a second attempt and had a subsequent PK. Despite successful anatomic attachment, 1 eye had primary graft failure, 3 that cleared initially failed within 6 months, and 1 that successfully cleared had subsequent graft rejection resulting in failure at 6 months. The 2 eyes requiring PK were excluded from the visual outcomes analysis, leaving 28 eyes with successfully attached lenticles. At 3 months postoperatively, of the 28 eyes, 19 showed an improvement in visual acuity, 6 had no change in vision from preoperative data, and 1 had worsening of vision (anatomic attachment but endothelial failure). Two of the 28 eyes had no data at that time point. DSAEK eyes after failed PK demonstrated improved vision with a low complication rate in a majority of patients. The graft dislocation rate and postoperative complications rates are comparable with the primary DSAEK dislocation rates in our own published series and in the literature.

  10. Laser welding to assist penetrating keratoplasty: in vivo studies

    NASA Astrophysics Data System (ADS)

    Menabuoni, Luca; Mincione, F.; Mincione, G. P.; Pini, Roberto

    1998-01-01

    Laser-induced corneal welding has been tested in vivo to perform experimental trials of penetrating keratoplasty (corneal transplantation). Twenty rabbits of 2500 - 3500 g in weight were selected to undergo laser-assisted corneal transplantation and then subjected to follow up on 2 - 15 postoperative days. Good sealing along the entire cut length was obtained soon after the surgical operation. Histology examinations evidenced that the laser-assisted surgical procedure provides a satisfactory healing process of corneal tissue in times that are substantially shorter than those of the conventional procedure.

  11. Two-step LASIK after penetrating keratoplasty

    PubMed Central

    Kollias, Aris N; Schaumberger, Markus M; Kreutzer, Thomas C; Ulbig, Michael W; Lackerbauer, Carlo A

    2009-01-01

    Purpose: The point of interest of this retrospective case review is to study refractive changes caused by the hinged lamellar keratotomy and the refractive outcome after laser ablation in a second step within the scope of laser in situ keratomileusis (LASIK) in patients with penetrating keratoplasty. Methods: Data from eight patients obtained before lamellar keratotomy, before laser ablation, and three months later were evaluated. Keratotomies were performed with the Moria® LSK one and the Amadeus® 2 microkeratome, laser ablation was performed with the Schwind® Keratome I and the Wavelight® Allegretto WaveEyeQ. Results: Uncorrected visual acuity (UCVA) improved significantly from 1 [logMar] to 0.4 [logMar] at the last visit. Median gain of UCVA was 7.38 ± 2.96 Snellen lines. Best spectacle-corrected visual acuity did not change significantly. Preoperative manifest refraction spherical equivalent decreased from −4.02 ± 4.77 diopters (D) to −1.11 ± 2.45 D after laser ablation. Mean preoperative manifest astigmatism was −7.27 ± 3.65 D, after lamellar keratotomy −6.72 ± 3.68 D, and after laser ablation −2.08 ± 1.80 D. Manifest astigmatism did not change significantly after the keratotomy. Conclusions: Lamellar keratotomy causes biomechanical changes to the cornea. We favor a two-step LASIK in penetrating keratoplasty patients in order to improve precision and predictability of the refractive outcome. PMID:19898662

  12. Simultaneous Penetrating Keratoplasty and Cataract Surgery

    PubMed Central

    Javadi, Mohammad-Ali; Feizi, Sepehr; Moein, Hamid-Reza

    2013-01-01

    Purpose To determine the clinical outcomes of simultaneous penetrating keratoplasty (PK), cataract removal and intraocular lens implantation (triple procedure), and to compare the safety and efficacy of two different cataract extraction techniques during the course of PK. Methods This retrospective comparative study was conducted on patients who had undergone a triple procedure. The technique of cataract extraction was either open- sky extracapsular cataract extraction (ECCE) or phacoemulsification (PE). In the ECCE group, the posterior chamber intraocular lens (PCIOL) was implanted in the ciliary sulcus, while in the PE group PCIOLs were fixated within the capsular bag. Outcome measures included best spectacle corrected visual acuity (BSCVA), refractive results, graft clarity and complications. Results Seventy-six eyes of 69 consecutive patients with mean age of 61.4±14.2 years were enrolled. Mean follow-up period was 61.4±37.2 months over which mean BSCVA was significantly improved from 1.40±0.68 to 0.44±0.33 LogMAR (P<0.001). Mean postoperative spherical equivalent refractive error was -2.13±3.02 D, which significantly differed from the target refraction (-0.73±0.29 D, P=0.004). At final follow-up, 89.5% of the corneal grafts remained clear. Conclusion The triple procedure is a safe and effective approach to restore vision in patients with coexisting corneal pathologies and cataracts. However, unacceptable postoperative refractive error can be anticipated. PMID:23825711

  13. Secondary implantation of a double intraocular lens after penetrating keratoplasty.

    PubMed

    Gayton, J L

    1998-02-01

    Penetrating keratoplasty (PKP) patients often have severe, visually disabling refractive errors. Astigmatism can be addressed by refractive surgery; however, correcting hyperopia is more problematic. Although pseudophakic PKP patients can have a lens exchange, it can be traumatic in this population. In this pseudophakic PKP patient, I added a second posterior chamber intraocular lens, correcting the hyperopia and resolving visual complaints.

  14. Peribulbar anaesthesia for penetrating keratoplasty. A case series.

    PubMed

    Agrawal, Vinay; Tharoor, Madhusoodan

    2002-12-01

    To prospectively analyse the efficacy and safety of peribulbar anaesthesia for penetrating keratoplasty through a noncomparative, consecutive series. One hundred twenty-four (91.1%) of 136 patients undergoing penetrating keratoplasty (PK) from January 1997 to December 2001, were administered peribulbar anaesthesia. The anaesthetic mixture consisted 5 ml of lignocaine, bupivacaine, and hyaluronidase (to avoid evaluation bias) in the peribulbar space. A repeat injection of 3 ml was used if the primary injection was inadequate. Digital ocular compression was done for 10-15 minutes after the first injection. Each patient was analysed for degree of akinesia, subjective patient comfort, analgesia, subjective surgeon comfort, and types of surgical conditions. The age ranged from 19 to 86 years. Forty-nine of 124 patients (39.5%) received PK only and remaining 75 patients (60.5%) received additional procedures. A single injection was sufficient to achieve adequate akinesia (grade II and III) in 114 (92%) patients and 120 (97%) of patients were satisfied (graded pain as < or = grade II). During surgery, 6 (5%) phakic eyes developed episodes of positive intraocular pressure and 5 eyes (4%) developed chemosis. There were no other local or systemic adverse events. The surgeon level comfort was (grade II or more) 98% (122 of 124). One-point, low volume, peribulbar anaesthesia for penetrating keratoplasty is safe and efficacions.

  15. [Corneal transplantation in keratoconus: penetrating keratoplasty versus deep anterior lamellar keratoplasty with Melles technique].

    PubMed

    Cano-Ortiz, A; Villarrubia, A

    2015-01-01

    To evaluate the effectiveness of deep anterior lamellar keratoplasty (DALK) using Melles technique (technique B) in patients with advanced keratoconus versus a classic technique, penetrating keratoplasty (technique A). Retrospective descriptive comparative study between technique A and technique B in homogeneous groups. Best corrected visual acuity (Snellen test decimal scale) was 0.77±0.32 for group A and 0.62±0.29 for group B, with no statistically significant differences. The mean spherical final refraction in group A was 1.73±5.1 diopters, and the mean spherical equivalent was -3.92±5.1. Technique B group gave values -2.67±4.02 diopters and -4.55±4.08 diopters, respectively, with no statistically significant differences. The residual cylinder after removal of the sutures was 4.47±2.47 diopters for group A and 3.77±1.63 for group B, with no statistically significant differences. No statistically significant differences were found for any of the studied variables when comparing both groups using the t -test for independent samples. More studies on the homogeneity and residual stromal bed thickness could provide the key to determine whether this technique is closer to the visual acuity of penetrating keratoplasty or DALK by a descemet technique. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  16. Anterior lamellar keratoplasty over penetrating keratoplasty for optical, therapeutic, and tectonic indications: a case series.

    PubMed

    Ang, Marcus; Mehta, Jodhbir S; Arundhati, Anshu; Tan, Donald T H

    2009-04-01

    To report a consecutive case series of patients who underwent anterior lamellar keratoplasty (ALK) over a preexisting penetrating keratoplasty (PK). Retrospective, interventional case series. Eight patients (8 eyes) were identified from the Singapore Corneal Transplant Study database, in a single institution (Singapore National Eye Center) from patients who underwent ALK performed over a PK. Main outcome measures were final visual acuity (VA), graft failure (ALK, PK or both), successful restoration of tectonic integrity in tectonic indications, and eradication of infection in therapeutic cases. The indications for surgery were therapeutic in 3 patients, optical in 3 patients, and tectonic in 2 patients. Postoperatively the best-corrected visual acuity (BCVA) improved in 5 eyes and remained unchanged in 3 eyes. Mean VA improved significantly after ALK; the mean preoperative BCVA was 1.52 +/- 0.25 and the mean postoperative BCVA was 0.87 +/- 0.26 (P = .032). Three of the 8 eyes post-lamellar keratoplasty (LK) managed to attain a BCVA equal to post-PK BCVA. Two patients had suture micro-perforations while 1 patient required a repeat ALK for recurrence of infection. ALK may be a considered as a viable alternative to a repeat PK for a variety of optical, therapeutic, and tectonic indications.

  17. Comparative study of keratoconus between Anwar's deep anterior lamellar keratoplasty versus converted penetrating keratoplasty.

    PubMed

    Donoso, R; Díaz, C; Villavicencio, P

    2015-06-01

    To compare outcomes between penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) in patients with keratoconus. Retrospective cohort study. Data of 90 DALK and 49 procedures from conversion to PK, performed by a single surgeon (R.D.) from 2006 to 2011 were analysed. Outcomes on corrected distance visual acuity (BCVA), astigmatism, time to first refraction, pachymetry, endothelial count cell, and postoperative complications were compared between these groups. The mean age of the patients who underwent DALK and PK was 28.2 and 31.7 years, respectively (P=.17). The mean follow up for DALK and for the PK group was 14.7 and 19.4 months, respectively (P=.13). There was no significant difference between PK and DALK groups in the mean postoperative for: BCVA (LogMAR) (0.17 vs. 0.17; P=.59); refractive astigmatism (-3.19 vs.-3.01 diopters; P=.65), and time for the first subjective refraction (60.5 versus 68 days; P=.50). Main postoperative complications were 8% of endothelial rejection in PK group and 10% of deep stromal vascularization in DALK group. The only differences in postoperative results between groups were stromal neovascularization in DALK group and endothelial rejection in PK group. DALK should be considered as the first option when keratoplasty is indicated in keratoconus. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  18. Proposed classification for topographic patterns seen after penetrating keratoplasty

    PubMed Central

    Karabatsas, C.; Cook, S.; Sparrow, J.

    1999-01-01

    AIMS—To create a clinically useful classification for post-keratoplasty corneas based on corneal topography.
METHODS—A total of 360 topographic maps obtained with the TMS-1, from 95 eyes that had undergone penetrating keratoplasty (PKP), were reviewed independently by two examiners in a masked fashion, and were categorised according to a proposed classification scheme.
RESULTS—A high interobserver agreement (88% in the first categorisation) was achieved. At 12 months post-PKP, a regular astigmatic pattern was observed in 20/85 cases (24%). This was subclassified as oval in three cases (4%), oblate symmetric bow tie in six cases (7%), prolate asymmetric bow tie in six cases (7%), and oblate asymmetric bow tie in five cases (6%). An irregular astigmatic pattern was observed in 61/85 cases (72%), subclassified as prolate irregular in five cases (6%), oblate irregular in four cases (5%), mixed in seven cases (8%), steep/flat in 11 cases (13%), localised steepness in 16 cases (19%), and triple pattern in three cases (4%). Regular astigmatic patterns were associated with significantly higher astigmatism measurements. The surface asymmetry index was significantly lower in the regular astigmatic patterns.
CONCLUSIONS—In post-PKP corneas, the prevalence of irregular astigmatism is about double that of regular astigmatism, with a trend for increase of the irregular patterns over time.

 Keywords: keratoplasty; corneal topography; astigmatism PMID:10434860

  19. Da Vinci Xi Robot-Assisted Penetrating Keratoplasty.

    PubMed

    Chammas, Jimmy; Sauer, Arnaud; Pizzuto, Joëlle; Pouthier, Fabienne; Gaucher, David; Marescaux, Jacques; Mutter, Didier; Bourcier, Tristan

    2017-06-01

    This study aims (1) to investigate the feasibility of robot-assisted penetrating keratoplasty (PK) using the new Da Vinci Xi Surgical System and (2) to report what we believe to be the first use of this system in experimental eye surgery. Robot-assisted PK procedures were performed on human corneal transplants using the Da Vinci Xi Surgical System. After an 8-mm corneal trephination, four interrupted sutures and one 10.0 monofilament running suture were made. For each procedure, duration and successful completion of the surgery as well as any unexpected events were assessed. The depth of the corneal sutures was checked postoperatively using spectral-domain optical coherence tomography (SD-OCT). Robot-assisted PK was successfully performed on 12 corneas. The Da Vinci Xi Surgical System provided the necessary dexterity to perform the different steps of surgery. The mean duration of the procedures was 43.4 ± 8.9 minutes (range: 28.5-61.1 minutes). There were no unexpected intraoperative events. SD-OCT confirmed that the sutures were placed at the appropriate depth. We confirm the feasibility of robot-assisted PK with the new Da Vinci Surgical System and report the first use of the Xi model in experimental eye surgery. Operative time of robot-assisted PK surgery is now close to that of conventional manual surgery due to both improvement of the optical system and the presence of microsurgical instruments. Experimentations will allow the advantages of robot-assisted microsurgery to be identified while underlining the improvements and innovations necessary for clinical use.

  20. Economic evaluation of endothelial keratoplasty techniques and penetrating keratoplasty in the Netherlands.

    PubMed

    van den Biggelaar, Frank J H M; Cheng, Yanny Y Y; Nuijts, Rudy M M A; Schouten, Jan S A G; Wijdh, Robert-Jan; Pels, Elisabeth; van Cleynenbreugel, Hugo; Eggink, Catharina A; Rijneveld, Wilhelmina J; Dirksen, Carmen D

    2012-08-01

    To evaluate cost-effectiveness of penetrating keratoplasty (PK), femtosecond laser-assisted Descemet stripping endothelial keratoplasty (FS-DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK). Cost-effectiveness analysis based on data from a randomized multicenter clinical trial and a noncomparative prospective study. Data of 118 patients with corneal endothelial dysfunction were analyzed in the economic evaluation. Forty patients were included in the PK group, 36 in the FS-DSEK group, and 42 in the DSAEK group. The primary incremental cost-effectiveness ratio (ICER) was the incremental costs per clinically improved patient, defined as a patient with a combined effectiveness of both a clinically improved BSCVA (defined as an improvement of at least 2 lines) and a clinically acceptable refractive astigmatism (defined as less than or equal to 3.0 diopters). Analysis was based on a 1-year follow-up period after transplantation. The percentage of treated patients who met the combined effectiveness measures was 52% for DSAEK, 44% for PK, and 43% for FS-DSEK. Mean total costs per patient were €6674 (US$7942), €12 443 (US$14 807), and €7072 (US$8416) in the PK group, FS-DSEK group, and DSAEK group, respectively. FS-DSEK was less effective and more costly compared to both DSAEK and PK. DSAEK was more costly but also more effective compared to PK, resulting in incremental costs of €4975 (US$5920) per additional clinically improved patient. The results of this study show that FS-DSEK was not cost-effective compared to PK and DSAEK. DSAEK, on the other hand, was more costly but also more effective compared to PK. Including societal costs, a longer follow-up period and preparation of the lamellar transplant buttons in a national cornea bank could improve the cost-effectiveness of DSAEK. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Penetrating keratoplasty versus lamellar keratoplasty for mustard gas-induced keratitis.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad A; Jafarinasab, Mohammad R; Karimian, Farid

    2013-04-01

    To compare the outcomes of penetrating keratoplasty (PK) and lamellar keratoplasty (LK) in patients with mustard gas keratitis. A total of 78 eyes of 55 patients with mustard gas keratitis were included. Of these eyes, 27 (34.6%) underwent PK and 51 (63.4%) received LK. Keratolimbal allografts were performed in 11 and 30 eyes of the PK and LK groups, respectively. The study groups were compared in terms of best spectacle-corrected visual acuity, refractive error, and keratometry readings. The Kaplan-Meier survival curve and log-rank test were used to evaluate and compare the cumulative incidence of rejection-free graft survival and graft survival in PK and LK. At the time of keratoplasty, the mean patient ages were 40.3 ± 4.5 years and 43.4 ± 8.3 years in the PK and LK groups, respectively (P = 0.08). The patients were followed-up for 53.2 ± 27.5 and 40.4 ± 29.6 months, respectively (P = 0.09). At the last follow-up, the 2 study groups were comparable with respect to best spectacle-corrected visual acuity (P = 0.87), refraction (P = 0.08), and keratometric astigmatism (P = 0.27). At the 33-month follow-up examination, the rejection-free graft survival rates were 33.6% in the PK group and 90% in the LK group, with mean durations of 34.6 and 84.8 months, respectively (P < 0.001). Moreover, the graft survival rates were 77.3% and 91.7%, with mean durations of 67.5 and 76.1 months, respectively (P = 0.03). Three eyes that had received LK underwent PK because of significant interface haziness. LK is preferred to PK in the majority of mustard gas victims. However, PK should always be performed in certain conditions.

  2. Postkeratoplasty Anterior and Posterior Corneal Surface Wavefront Analysis: Descemet's Stripping Automated Endothelial Keratoplasty versus Penetrating Keratoplasty

    PubMed Central

    Salvetat, Maria L.; Zeppieri, Marco; Miani, Flavia; Brusini, Paolo

    2013-01-01

    Purpose. To compare the higher-order aberrations (HOAs) due to the anterior and posterior corneal surfaces in patients that underwent either Descemet-stripping-automated-endothelial-keratoplasty (DSAEK) or penetrating keratoplasty (PK) for endothelial dysfunction and age-matched controls. Methods. This retrospective, observational, case series included 28 patients after PK, 30 patients after DSAEK, and 30 healthy controls. A Scheimpflug imaging system was used to assess the HOAs due to the anterior and posterior corneal surfaces at 4 mm and 6 mm optical zones. Total, 3rd and 4th order HOAs were considered. Intra- and intergroup differences were assessed using the Friedman and the Kruskal-Wallis tests, respectively; paired comparisons were performed using Duncan's multiple range test. Results. Total, 3rd and 4th order HOAs due to both corneal surfaces at 4 mm and 6 mm optical zones were significantly higher in the PK group, intermediate in the DSAEK group, and lower in controls (P < 0.05). The most important HOAs components in both PK and DSAEK groups were trefoil and coma from the anterior corneal surface (P < 0.05) and trefoil from the posterior corneal surface (P < 0.05). Conclusions. The optical quality of both corneal surfaces appeared significantly higher after DSAEK than after PK, which can increase the postoperative patient's quality of vision and satisfaction. PMID:24558599

  3. Ten-year postoperative results of penetrating keratoplasty.

    PubMed

    Ing, J J; Ing, H H; Nelson, L R; Hodge, D O; Bourne, W M

    1998-10-01

    To investigate the changes in central corneal endothelial cells and corneal thickness in transplanted corneas from 5 to 10 years after grafting. This study also aimed to investigate the development of glaucoma, graft rejection, and graft failure during the first 10 postoperative years. Longitudinal cohort study of 500 consecutive penetrating keratoplasties by 1 surgeon. Patients were asked to return for follow-up examinations at 2 months and at 1, 3, 5, and 10 years after grafting. The authors excluded eyes regrafted during the study and the fellow eyes of bilateral cases, leaving 394 grafts in 394 patients for analysis. Penetrating keratoplasty was performed. Using specular microscopy, the authors measured endothelial cell density, coefficient of variation of cell area, percentage of hexagonal cells, and corneal thickness. The authors performed clinical examinations to determine graft rejection or failure and the development of glaucoma. By 10 years postkeratoplasty, 80 of the 394 patients had died and 68 grafts had failed. Of the remaining 246 patients, 119 (48%) returned for their 10-year examinations. For the 72 patients who returned for all of the scheduled postoperative visits and had no rejection episodes, reoperations, or failure, endothelial cell loss from preoperative donor levels at 10 years was 67 +/- 18% (mean +/- standard deviation), endothelial cell density was 958 +/- 471 cells/mm2, coefficient of variation was 0.32 +/- 0.11, hexagonal cells were 56 +/- 12%, and corneal thickness was 0.58 +/- 0.05 mm. The 5- to 10-year changes for all these values were significant (P < or = 0.004). The mean rate of late endothelial cell loss from 5 to 10 years postkeratoplasty was 4.2% per year. Eyes that were aphakic after grafting had the lowest endothelial cell loss (57 +/- 24%) and the lowest interval cell loss from 5 to 10 years postkeratoplasty (4 +/- 19%). Eyes that were phakic had the highest endothelial cell loss (73 +/- 8%) and 5- to 10-year-interval cell

  4. [DALK and penetrating laser keratoplasty for advanced keratoconus].

    PubMed

    Seitz, B; Cursiefen, C; El-Husseiny, M; Viestenz, A; Langenbucher, A; Szentmáry, N

    2013-09-01

    In cases of contact lens intolerance and/or central corneal scars, corneal transplantation is indicated for advanced keratoconus. This can be performed as deep anterior lamellar keratoplasty (DALK) or as penetrating keratoplasty (PKP). The German keratoplasty registry shows that the proportion of anterior lamellar grafts in Germany has remained stable at approximately 5 % in recent years. Up to now DALK has not been technically standardized but can result in a good visual acuity using the big bubble technique if Descemet's membrane is laid bare intraoperatively. In 10-20 % a conversion to PKP is required if perforation of Descemet's membrane occurs. In cases of advanced keratoconus PKP is still the method of first choice especially after corneal hydrops due to rupture of Descemet's membrane. Non-contact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in cases of keratoconus recurrence due to the graft being too small. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved by a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size (as large as possible and as small as necessary). Limbal centration is given priority intraoperatively due to optical displacement of the pupil. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces vertical tilt and horizontal torsion of the graft in the recipient bed, thus resulting in significantly less all-sutures-out keratometric astigmatism (2.8 D versus 5.7 D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. In cases with optimal course DALK achieves the same visual

  5. [Corneal wound healing after experimental penetrating keratoplasty after excimer laser trephination in free form].

    PubMed

    Schmitz, K; Lang, G K; Behrens-Baumann, W

    2006-12-01

    The postoperative clinical course after penetrating keratoplasty and trephination in free form using a guided excimer laser beam has been published before. Here the findings of light-microscopy comparing corneal wound healing after experimental penetrating keratoplasty after laser trephination and after conventional mechanical trephination are presented. Homologous penetrating keratoplasty was performed on 12 NZW rabbits (6 animals with mechanical trephination, 6 animals with excimer laser trephination). The cutting edges achieved by both trephination techniques were examined by light microscopy in the remaining donor rings. During the postoperative follow-up animals were sacrificed at 3 and 6 weeks and at 3 months. Corneal specimens were retrieved and corneal healing processes were evaluated by light microscopy. The cutting edges of corneal excisions with the excimer laser demonstrated a high precision with only minimal collateral damage to adjacent tissue structures. At the different intervals both trephination groups demonstrated comparable stages of corneal wound healing regarding epithelial regeneration, stromal fibroblast migration with collagen synthesis and Descemet repair by endothelial synthesis of basement membrane. After 6 months corneal specimens of both groups demonstrated complete healing with nearly parallel orientation of newly synthesised collagen lamellae. Corneal thickness in the wound areas did not differ significantly from normal corneal tissue. Experimental follow-up studies to evaluate the feasibility of the developed technology of laser trephination in the living eye have shown no differences between conventional mechanical and excimer laser trephination with a guided beam. The present histology study also does not demonstrate any significant differences in corneal wound healing between the two trephination groups. Although excimer laser trephination along metal masks has now been established for several years, the here presented technique

  6. [Penetrating keratoplasty for keratoconus in a case of Down's syndrome].

    PubMed

    Goto, S; Minoda, S; Suzuki, S

    1995-02-01

    We report a Down's syndrome patient who underwent penetrating keratoplasty (PKP) surgery. The patient was a 62-year-old female who had Down's syndrome with severe bilateral keratokonus and cataract. Her visual acuity was very poor as she did everything by touch before the surgery. We performed a triple procedure surgery, i.e., PKP, extracapsular cataract extraction, and posterior chamber intraocular lens implantation in her left eye. After the surgery her visual behavior improved markedly. This case shows that PKP surgery can be performed on such handicapped patients who are difficult handle in emergencies and need general anesthesia, because we have been able to keep the donor cornea longer than usual. We conclude that we should actively perform the PKP surgery for the handicapped if the patient does not have self-damaging behavior and if there is cooperation of the family and the medical staff.

  7. Morphological changes in corneal endothelial cells after penetrating keratoplasty.

    PubMed

    Laing, R A; Sandstrom, M; Berrospi, A R; Leibowitz, H M

    1976-09-01

    Fifteen patients who had had a successful penetrating keratoplasty were photographed with the clinical specular microscope and the resulting endothelial photomicrographs were analyzed. The average endothelial cell area was one to six times larger and the average endothelial cell perimeter was one to 2 1/2 times larger than that of a normal cornea of a subject the same age as the donor. In each corneal graft, endothelial cell areas and perimeters clustered tightly around a mean value, although the mean value for different corneas varied significantly. The thickness and transparency of each graft was normal, indicating that within the observed limits the success of the transplantation procedure did not depend on final endothelial cell size or perimeter.

  8. Five-Year Graft Survival Comparing Descemet Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty.

    PubMed

    Ang, Marcus; Soh, Yuqiang; Htoon, Hla Myint; Mehta, Jodhbir S; Tan, Donald

    2016-08-01

    To compare 5-year graft survival after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK) in Asian eyes. Prospective, nested, cohort study. Consecutive patients who underwent DSAEK (423 eyes) or PK (405 eyes) for Fuchs' endothelial dystrophy (FED) or bullous keratopathy (BK). Clinical data and donor and recipient characteristics were recorded from our prospective cohort from the Singapore Corneal Transplant Registry. All surgeries were performed by the corneal surgeons at our center, which included cases performed or partially performed by corneal fellows in training under direct supervision. Five-year cumulative graft survival. Overall mean age was 67.8±9.8 years, and 50.1% of patients were men. There were no significant differences in age (P = 0.261) or gender (P = 0.78) between PK and DSAEK groups in our predominantly Chinese (76.6%) Asian cohort, with more BK compared with FED (68.1% vs. 31.9%; P < 0.001). Overall 5-year graft survival was superior for DSAEK compared with PK (79.4% vs. 66.5%; P < 0.001, log-rank test). Median 5-year percent endothelial cell density loss was significantly greater in PK compared with DSAEK (60.9% vs. 48.7%; P = 0.007). Cox regression analysis revealed that BK was a significant factor associated with graft failure (hazard ratio [HR], 3.30; 95% confidence interval [CI], 2.05-5.33; P < 0.001), and PK was more likely to fail compared with endothelial keratoplasty (HR, 1.61; 95% CI, 1.08-2.41; P = 0.02) adjusting for confounders such as recipient age, gender, and donor factors. Five-year cumulative incidence of complications such as graft rejection (P < 0.001), epitheliopathy (P < 0.001), suture-related corneal infections (P < 0.001), and wound dehiscence (P = 0.002) were greater in the PK group compared with the DSAEK group. In Asian eyes from the same study cohort with standardized surgical and postoperative regimes, 5-year graft survival was superior for DSAEK compared with

  9. Systematic review comparing penetrating keratoplasty and deep anterior lamellar keratoplasty for management of keratoconus.

    PubMed

    Henein, Christin; Nanavaty, Mayank A

    2017-02-01

    Perception of reduced incidence of graft rejection after deep anterior lamellar keratoplasty (DALK) has attracted many surgeons towards this technique in keratoconus. This review aims to compare the visual, refractive and graft outcomes after penetrating keratoplasty (PK) and DALK for keratoconus. Electronic searches of PubMed, MEDLINE, EMBASE, Latin American and Caribbean Health Sciences Literature database (LILACS), metaRegister of Controlled Trials (mRCT), ClinicalTrial.gov and the WHO International Clinical Trials Registry Platform (ICTRP) were performed. We included randomized control trials (RCTs) and comparative studies to assess primary and secondary outcomes after PK and DALK in eyes with keratoconus. Primary outcome was best-corrected visual acuity (BCVA) LogMAR at ≥6 months. Secondary outcomes included number of patients with BCVA≥0 LogMAR, uncorrected visual acuity (UCVA) LogMAR, spherical equivalent (SE), refractive and keratometric astigmatism, endothelial cell density (ECD) cell/mm(2), graft rejection and graft survival. Eighteen studies (including 2 RCTs) compared DALK (965 eyes) and PK (2402 eyes) for keratoconus. There was strong evidence through RCTs suggesting better LogMAR BCVA at ≥6 months and better LogMAR UCVA with PK; reduced refractive astigmatism and rejection with DALK and no difference in SE and keratometric astigmatism. Moreover, there was weak evidence to suggest better BCVA≥0 LogMAR after PK and no difference in ECD between the two techniques. Despite the popularity of DALK amongst corneal surgeons for keratoconus, there is a paucity of high quality RCTs. The existing limited evidence confirms reduced rejection and refractive astigmatism with DALK but better visual outcomes with PK. Internationally agreed data sets and follow-up protocol are warranted. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  10. Economic evaluation of deep anterior lamellar keratoplasty versus penetrating keratoplasty in The Netherlands.

    PubMed

    van den Biggelaar, Frank J H M; Cheng, Yanny Y Y; Nuijts, Rudy M M A; Schouten, Jan S; Wijdh, Robert-Jan; Pels, Elisabeth; van Cleynenbreugel, Hugo; Eggink, Catharina A; Zaal, Michel J W; Rijneveld, Wilhelmina J; Dirksen, Carmen D

    2011-03-01

    To evaluate the cost effectiveness of deep anterior lamellar keratoplasty (DALK) versus penetrating keratoplasty (PK) in The Netherlands. Cost-effectiveness analysis alongside a randomized, multicenter clinical trial. Fifty-three patients with corneal stromal pathologic features not affecting the endothelium were included with 28 patients in the DALK group and 25 in the PK group. Quality of life was measured before surgery and 3, 6, and 12 months after surgery. The main outcome measures were incremental cost-effectiveness ratios per clinically improved patient on the 25-item National Eye Institute Visual Functioning Questionnaire and per patient with endothelial cell loss of maximally 20% within the first year. Mean total bootstrapped costs per patient were €7607 (US$10,498) in the DALK group and €6552 (US$9042) in the PK group. The incremental cost-effectiveness ratios were €9977 (US$13,768) per clinically improved patient on the 25-item National Eye Institute Visual Functioning Questionnaire and €6900 (US$9522) per patient with cell loss of maximally 20%. In patients without perforation of the Descemet membrane, the incremental cost-effectiveness ratio was €5250 (US$7245) per patient. This study shows that DALK is more costly and more effective as compared with PK. Results on the 25-item National Eye Institute Visual Functioning Questionnaire were in favor of DALK, and endothelial cell loss in DALK patients remained stable after 6 months, whereas cell loss in PK patients continued. Furthermore, DALK procedures performed without perforation of the Descemet membrane were more effective. However, because it is unknown what society is willing to pay for an additional improved patient, cost effectiveness of DALK within a limited follow-up period of 12 months is unclear. Cost effectiveness of DALK may improve over time because of lower graft failure. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Penetrating Keratoplasty for Keratoconus - Excimer Versus Femtosecond Laser Trephination.

    PubMed

    Seitz, Berthold; Langenbucher, Achim; Hager, Tobias; Janunts, Edgar; El-Husseiny, Moatasem; Szentmáry, Nora

    2017-01-01

    In case of keratoconus, rigid gas-permeable contact lenses as the correction method of first choice allow for a good visual acuity for quite some time. In a severe stage of the disease with major cone-shaped protrusion of the cornea, even specially designed keratoconus contact lenses are no more tolerated. In case of existing contraindications for intrastromal ring segments, corneal transplantation typically has a very good prognosis. In case of advanced keratoconus - especially after corneal hydrops due to rupture of Descemet's membrane - penetrating keratoplasty (PKP) still is the surgical method of first choice. Noncontact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in case of "keratoconus recurrences" due to small grafts with thin host cornea. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved with a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size ("as large as possible - as small as necessary"). Limbal centration will be preferred intraoperatively due to optical displacement of the pupil. During the last 10 years femtosecond laser trephination has been introduced from the USA as a potentially advantageous approach. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces "vertical tilt" and "horizontal torsion" of the graft in the recipient bed, thus resulting in significantly less "all-sutures-out" keratometric astigmatism (2.8 vs. 5.7 D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. Refractive outcomes of femtosecond laser keratoplasty, however, resemble that of the motor trephine. In

  12. Penetrating Keratoplasty for Keratoconus – Excimer Versus Femtosecond Laser Trephination

    PubMed Central

    Seitz, Berthold; Langenbucher, Achim; Hager, Tobias; Janunts, Edgar; El-Husseiny, Moatasem; Szentmáry, Nora

    2017-01-01

    Background: In case of keratoconus, rigid gas-permeable contact lenses as the correction method of first choice allow for a good visual acuity for quite some time. In a severe stage of the disease with major cone-shaped protrusion of the cornea, even specially designed keratoconus contact lenses are no more tolerated. In case of existing contraindications for intrastromal ring segments, corneal transplantation typically has a very good prognosis. Methods: In case of advanced keratoconus – especially after corneal hydrops due to rupture of Descemet’s membrane – penetrating keratoplasty (PKP) still is the surgical method of first choice. Noncontact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in case of “keratoconus recurrences” due to small grafts with thin host cornea. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved with a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size („as large as possible – as small as necessary“). Limbal centration will be preferred intraoperatively due to optical displacement of the pupil. During the last 10 years femtosecond laser trephination has been introduced from the USA as a potentially advantageous approach. Results: Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces “vertical tilt” and “horizontal torsion” of the graft in the recipient bed, thus resulting in significantly less “all-sutures-out” keratometric astigmatism (2.8 vs. 5.7 D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. Refractive outcomes of femtosecond laser

  13. Comparison of femtosecond laser-assisted deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus.

    PubMed

    Chen, Yueqin; Hu, Dan-Ning; Xia, Yuan; Yang, Liping; Xue, Chunyan; Huang, Zhenping

    2015-10-27

    To compare outcomes of femtosecond laser-assisted deep anterior lamellar keratoplasty (FSL-DALK) and penetrating keratoplasty (FSL-PK) for the treatment of keratoconus. Twenty eight eyes underwent FSL-DALK (consisted of 12 eyes in the FSL-DALKa subgroup without baring the Descemet's membrane and 16 eyes in the FSL-DALKb subgroup baring the Descemet's membrane using big-bubble technique) were compared with 12 eyes that underwent FSL-PK for keratoconus. These patients underwent an ophthalmic examination preoperatively and 3, 6, 9, and 12 months postoperatively. The postoperative BCVA in the FSL-PK group, and the FSL-DALKb subgroup were significantly better than that in the FSL-DALKa subgroup (P < 0.05), whereas no differences were found between the FSL-DALKb subgroup and the FSL-PK group (P > 0.05). There were no significant differences in the mean spherical equivalent (SE) and astigmatism between the FSL-DALK and the FSL-PK groups, nor between the subgroups of FSL-DALK during the follow-up period (P > 0.05). At the last follow-up, the mean endothelial cell loss in the FSL-DALK group (9.12 %) was significantly less than that in the FSL-PK group (20.79 %) (P < 0.001), while there was no difference between the FSL-DALKa (9.15 %) and the FSL-DALKb (9.10 %) subgroups (P = 0.15). The FSL-DALK group seemed to have fewer graft rejections (1/28 cases) than the FSL-PK group (2/12 cases), although Kaplan-Meier curve showed no significant difference between the two groups (P = 0.144). In this retrospective study, the results suggested that FSL-DALKb gives better visual outcome, and FSL-DALKb is a better option for keratoconus whose endothelium is not compromised. However, larger and prospective studies are further required.

  14. Defining success in infant penetrating keratoplasty for developmental corneal opacities.

    PubMed

    Medsinge, Anagha; Speedwell, Lynne; Nischal, Ken K

    2014-01-01

    Neonatal corneal opacities (NCO) are one of the common causes of visual impairment in infants. We present the two infants with penetrating keratoplasty (PKP) for unilateral NCO with different visual and graft outcomes, and illustrate the importance of timing of surgery, importance of visual rehabilitation, and the lack of necessity of a clear graft to achieve reasonable visual function in infants with NCO. Two infants with unilateral NCO (Peters anomaly) underwent PKP at age of 5.5 weeks (Case One) and 16 weeks (Case Two). Postoperative optical correction, amblyopia therapy, visual and graft outcomes were recorded. At the last follow-up (9.5 years in both the cases), Case One achieved a best-corrected visual acuity (BCVA) of 20/80 with -22 D of contact lens. The graft had a small clear zone centrally but otherwise was opacified to some extent. Case Two achieved a BCVA of 20/125 at 30 cms eccentrically with a clear graft. Case Two was uncooperative for amblyopia therapy and optical treatment. For a successful visual outcome in NCO, early PKP, aggressive amblyopia therapy, optical correction, and commitment from the parents for longterm follow-up and demanding treatment are required. © 2014 Board of regents of the University of Wisconsin System, American Orthoptic Journal, Volume 64, 2014, ISSN 0065-955X, E-ISSN 1553-4448.

  15. Penetrating keratoplasty: indications over a 10 year period

    PubMed Central

    Al-Yousuf, N; Mavrikakis, I; Mavrikakis, E; Daya, S M

    2004-01-01

    Aims: To determine the indications for penetrating keratoplasty (PK) at the Corneoplastic Unit and Eye Bank, UK, a tertiary referral centre, over a 10 year period. Methods: Records of all patients who underwent PK at our institution between 1990 and 1999 were reviewed retrospectively. Of the 1096 procedures performed in this period, 784 records were available for evaluation (72%). Results: Regrafting was the most common indication, accounting for 40.9% of all cases. Keratoconus was the second most common indication (15%), followed by Fuchs’ endothelial dystrophy (9.3%), pseudophakic bullous keratopathy (7.6%), and viral keratitis (5.9%), which included both herpes simplex and herpes zoster and showed a statistically significant decreasing trend using regression analysis (p<0.005). Among the regraft subgroup, viral keratitis accounted for 21.2% as the underlying primary diagnosis. The most common cause for graft failure in the regraft subgroup was endothelial failure (41.8%). Conclusion: Regrafting is the leading indication for PK; viral disease—although declining—is the leading primary diagnosis. PMID:15258012

  16. Penetrating keratoplasty for keratoconus with or without vernal keratoconjunctivitis.

    PubMed

    Wagoner, Michael D; Ba-Abbad, Rola

    2009-01-01

    The purpose of this study was to evaluate graft survival, postoperative complications, and visual outcome after penetrating keratoplasty (PKP) for keratoconus (KC) in eyes with or without a history of vernal keratoconjunctivitis (VKC). A retrospective review was conducted on all cases of PKP performed at King Khaled Eye Specialist Hospital between January 1, 1997, and December 31, 2001, for KC. Four hundred sixty-four eyes were included in the study, including 80 (17.2%) eyes with VKC and 384 (82.8%) without VKC. Five-year graft survival was 97.3% and 95.5% in eyes with or without VKC, respectively. There were no statistically significant differences in Kaplan-Meier graft survival between the 2 groups at any time interval. There were no statistically significant differences in the percentage of eyes experiencing postoperative complications in eyes with or without VKC (27.5% vs 31.8%, respectively; P = 0.50). However, late-onset persistent epithelial defects were significantly more likely to occur in eyes with VKC (6.3% vs 1.8%; P = 0.04). There were no significant differences in the prevalence of endothelial rejection, bacterial keratitis, glaucoma, wound dehiscence, early-onset persistent epithelial defects, or secondary cataract. The median final best-corrected visual acuity was 20/30 in both groups. The percentage of eyes with a final best-corrected visual acuity of 20/40 or better was 76.2% in eyes with VKC and 71.9% in eyes without VKC (P = 0.49). Graft survival, postoperative complications, and visual outcome are comparable after PKP for KC in eyes with or without VKC.

  17. Urrets-Zavalia syndrome following penetrating keratoplasty for keratoconus.

    PubMed

    Figueiredo, Gustavo S; Kolli, Sai S P; Ahmad, Sajjad; Gales, Kevin; Figueiredo, Francisco C

    2013-03-01

    Urrets-Zavalia syndrome (UZS) consists of a fixed dilated pupil associated with iris atrophy. It is a poorly understood complication following penetrating keratoplasty (PKP) for keratoconus (KC). In this work, we aim to establish the incidence, visual outcomes, and an understanding of UZS. This was a retrospective single-center study in a tertiary eye service in the United Kingdom of consecutive patients with UZS following PKP for KC in a 10-year period. Post-operative complications, including raised intraocular pressure (IOP), were recorded. UZS patients and age-matched control patients who had undergone PKP for KC without developing UZS attended a comprehensive clinical assessment. Anterior segment indocyanine green (ICG) angiography assessed iris perfusion. The incidence of UZS was 16.2 %. There was no difference in LogMAR VA or Pelli-Robson contrast sensitivity between groups. There was higher first-day post-operative IOP in UZS (p = 0.02). UZS patients had increased pupil size (p = 0.09) with reduced response to pilocarpine 2 % (p < 0.001). ICG angiography revealed delayed/reduced iris vasculature filling in UZS compared with normal filling patterns of controls. Elevated post-operative IOP within 24 h was a significant factor in the development of UZS. Visual function in UZS patients was unaffected. UZS patients developed longstanding mydriasis with reduced reactivity to topical pilocarpine 2 %. ICG angiography confirmed iris vessel ischemia; supporting the theory that iris ischemia resulting from occlusion of iris root vessels due to elevated IOP causes UZS. We advocate rigorous intraoperative management of ocular viscoelastic devices and aggressive postoperative IOP control in patients undergoing PKP for KC.

  18. Shifting trends in microbial keratitis following penetrating keratoplasty in Taiwan

    PubMed Central

    Chen, Hung-Chi; Lee, Chia-Yi; Lin, Hung-Yu; Ma, David Hui-Kang; Chen, Phil Yeong-Fong; Hsiao, Ching-Hsi; Lin, Hsin-Chiung; Yeh, Lung-Kun; Tan, Hsin-Yuan

    2017-01-01

    Abstract To investigate the clinical and microbiological profiles from microbial keratitis following penetrating keratoplasty (PKP) in a tertiary referral center in Taiwan, the medical records of 648 consecutive patients (648 eyes) undergoing PKP between January 2003 and December 2007 were retrospectively reviewed. Patients who subsequently sustained microbial keratitis were enrolled and analyzed for potential risk factors, clinical manifestations, microbiological profiles, complications, graft survival, and final visual outcome. A total number of 42 corneal graft infections (6.5%) were recruited. Mean interval between corneal transplantation and graft infection was 12 ± 9.5 months. Potential risk factors included suture-related problems (31.0%), lid abnormalities (23.8%), persistent epithelial defect (23.8%), contact lens use (14.3%), dry eye (11.9%), and prior rejection episodes (4.8%). Lesions were discovered mostly at the donor-recipient junction ([DRJ] 45.2%). Positive cultures were identified in all of the morbid eyes, of which Pseudomonas aeruginosa was the most common pathogen (38.1%). Despite mandatory hospitalization and topical fortified antibiotics management, complications ensued such as graft failure (71.4%), hypopyon (21.4%), corneal perforation (14.3%), wound dehiscence (11.9%), and endophthalmitis (4.8%). The visual outcome was dismal that graft clarity was achieved in only 12 eyes (28.6%), and that final visual acuity deteriorated to less than 20/200 in 28 eyes (66.7%). In conclusion, microbial keratitis following PKP is a devastating event that severely impairs graft survival rate and postoperative visual outcome which usually occur within the first postoperative year. The incidence of post-PKP microbial keratitis has generally decreased in recent years whilst P. aeroginosa prevails as the leading cause of graft infection in our hospital. Close follow-up by ophthalmologists and elevated self-awareness of patients for at least one year are

  19. Simultaneous Phacoemulsification and Graft Refractive Surgery in Penetrating Keratoplasty Eyes

    PubMed Central

    Feizi, Sepehr; Zare, Mohammad; Einollahi, Bahram

    2011-01-01

    Purpose. To report outcomes of graft refractive surgery (GRS) along with clear-cornea phacoemulsification and intraocular lens (IOL) implantation in penetrating keratoplasty (PKP) eyes. Methods. Fourteen eyes of 13 patients who had received PKP underwent simultaneous GRS (relaxing incisions with or without counter-quadrant compression sutures) and clear-cornea phacoemulsification with IOL implantation. To calculate IOL power, preoperative keratometry readings and the SRK-T formula were used. Results. Mean patient age and follow-up period were 50.5 ± 14.4 years and 14.6 ± 7.1 months, respectively. A significant increase was observed in best spectacle-corrected visual acuity (from 0.55 ± 0.18 logMAR to 0.33 ± 0.18 logMAR, P = 0.001). There was a significant decrease in vector keratometric astigmatism by 6.22 D (P = 0.03). Spherical equivalent refraction was reduced from −3.31 ± 3.96 D to −1.69 ± 2.38 D (P = 0.02) which did not significantly differ from the target refraction (−0.76 ± 0.14 D, P = 0.20). No complications developed and all the grafts remained clear at the final examination. Conclusion. Simultaneous phacoemulsification and GRS is a safe and effective method to address post-PKP astigmatism and lens opacity. IOL power can be calculated from preoperative keratometry readings with an acceptable accuracy. However, patients should be informed about the possibility of high refractive errors postoperatively. PMID:24527227

  20. Graft biomechanical properties after penetrating keratoplasty in keratoconus.

    PubMed

    Feizi, Sepehr; Einollahi, Bahram; Yazdani, Shahin; Hashemloo, Ali

    2012-08-01

    To measure corneal graft biomechanical properties after penetrating keratoplasty (PKP) in a group of keratoconic eyes using the ocular response analyzer (ORA) and to evaluate the relationship between donor size, donor-recipient disparity and central graft thickness (CGT), and ORA parameters. This cross-sectional study was conducted on 34 eyes of 34 keratoconus patients who had undergone PKP. Corneal hysteresis (CH), corneal resistance factor (CRF), and cornea-compensated intraocular pressure were measured at least 6 months after complete suture removal. Two groups of donor-recipient disparity (0.25 vs. 0.50 mm) were compared using the independent t test. Multivariate regression analysis was used to investigate the correlation of donor trephine size and CGT with ORA parameters. Factors influencing intraocular pressure measured with the Goldmann applanation tonometer (IOP GAT) after PKP were determined using multiple regression analysis. Mean patient age and follow-up period were 29.6 ± 6.2 years and 82.4 ± 59.6 months, respectively. Mean CGT, CH, and CRF were 564.7 ± 36.9 μm, 10.1 ± 2.1 mm Hg, and 10.0 ± 2.3 mm Hg, respectively. CH and CRF had a significant positive correlation with donor trephine size and CGT. Significantly greater values of CH and CRF were observed in the 0.5-mm disparity group compared with the 0.25-mm disparity group. Among the studied parameters, only CH, CRF, and cornea-compensated intraocular pressure had a significant positive correlation with IOP GAT. Graft biomechanics seem to be closer to normal values with larger grafts and greater donor-recipient disparity. These metrics had a significant correlation with IOP GAT after PKP.

  1. Long term observation of low-power diode laser welding after penetrating keratoplasty in human patients

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Matteini, Paolo; Pini, Roberto; Menabuoni, Luca; Lenzetti, Ivo

    2010-02-01

    Low power diode laser welding is a recently developed technique used as a support tool for conventional suturing in ophthalmic surgery. The main application is in penetrating keratoplasty: in the last four years (2005-2009), clinical trials were performed at the Ophthalmic Department of Prato, Italy). In penetrating keratoplasty, diode laser welding is used to assure the transplanted corneal button in its final position. The donor tissue is positioned in the recipient eye and 8-16 single stitches are apposed. The surgical wound is then stained with a saturated (10% w/w) sterile water solution of Indocyanine Green (ICG), it is washed with sterile water and then a diode laser (810 nm, 13 W/cm2) is used to induce the sealing of the wound. The laser light induces a thermal effect, localized in the stained tissue. In vivo and ex vivo studies in animal models evidenced that welding induces a modification of the corneal collagen architecture through the wound walls, thus enabling a short healing time and a good restoration of the tissue. In this study on human subjects, we confirmed the results evidenced in animal models, by morphological observations. In two cases out of 60, transplant rejection was observed. It was thus possible to study the efficacy of laser welding in the closure of the wound one year after implant. Direct morphological observation evidenced good strengthens of the welded tissue. Histological analysis pointed out a good restoration of the regular collagen architecture at the external perimeter of the corneal button, where laser welding was performed, showing the occurrence of a correct and effective wound healing process.

  2. Technique for air bubble management during endothelial keratoplasty in eyes after penetrating glaucoma surgery.

    PubMed

    Banitt, Michael; Arrieta-Quintero, Esdras; Parel, Jean-Marie; Fantes, Francisco

    2011-02-01

    Our purpose was to develop a technique for maintaining air within the anterior chamber during endothelial keratoplasty in eyes that have previously undergone trabeculectomy or a glaucoma drainage implant. Whole human globes and rabbits underwent penetrating glaucoma surgery to develop the technique. Without the aid of any additional device or manipulation, continuing to inject air into the anterior chamber as it escapes through the sclerostomy or tube eventually fills the subconjunctival space and allows for back pressure. This allows for a full anterior chamber air fill and brief elevation of intraocular pressure. We employed this overfilling technique on 3 patients with previous incisional glaucoma surgery to perform successful Descemet stripping endothelial keratoplasty without complication. We recommend using the overfilling technique when performing Descemet stripping endothelial keratoplasty surgery in eyes with previous penetrating glaucoma surgery because it is a simple technique without the need for pre- or postoperative manipulation.

  3. Clinical features of single and repeated globe rupture after penetrating keratoplasty.

    PubMed

    Murata, Noriaki; Yokogawa, Hideaki; Kobayashi, Akira; Yamazaki, Natsuko; Sugiyama, Kazuhisa

    2013-01-01

    In this paper, we report our experience of the clinical features of single and repeated globe rupture after penetrating keratoplasty. We undertook a retrospective analysis of single and repeated globe ruptures following keratoplasty in eight eyes from seven consecutive patients referred to Kanazawa University Hospital over a 10-year period from January 2002 to March 2012. We analyzed their ophthalmic and demographic data, including age at time of globe rupture, incidence, time interval between keratoplasty and globe rupture, cause of rupture, complicated ocular damage, and visual outcome after surgical repair. Five patients (71.4%) experienced a single globe rupture and two patients (28.6%) experienced repeated globe ruptures. Patient age at the time of globe rupture was 75.4 ± 6.8 (range 67-83) years. Four of the patients were men and three were women. During the 10-year study period, the incidence of globe rupture following penetrating keratoplasty was 2.8%. The time interval between penetrating keratoplasty and globe rupture was 101 ± 92 months (range 7 months to 23 years). The most common cause of globe rupture in older patients was a fall (n = 5, 79.8 ± 3.7 years, all older than 67 years). Final best-corrected visual acuity was >20/200 in three eyes (37.5%). In all except one eye, globe rupture involved the graft-host junction; in the remaining eye, the rupture occurred after disruption of the extracapsular cataract extraction wound by blunt trauma. Preventative measures should be taken to avoid single and repeated ocular trauma following penetrating keratoplasty.

  4. Shifting bubble-guided sutureless technique for performing descemetorhexis for retained Descemet's membrane after penetrating keratoplasty.

    PubMed

    Khokhar, Sudarshan; Agarwal, Tushar; Gupta, Shikha; Sehra, Srivats; Panda, Anita

    2014-02-01

    We describe the use of anterior segment optical coherence tomography in the diagnosis of inadvertent retention of Descemet's membrane (DM) after penetrating keratoplasty, and a novel technique for its removal in a case of congenital hereditary endothelial dystrophy. In this technique, we use a modification of the shifting bubble technique, commonly used in deep anterior lamellar keratoplasty where a viscocohesive ophthalmic viscosurgical device is injected into the false anterior chamber which causes migration of the central air bubble placed in the anterior chamber peripherally and helps in confirming the correct space. The DM is then peeled in a circular fashion with the help of 23-G vitreoretinal micro forceps.

  5. A comparison of lamellar and penetrating keratoplasty outcomes: a registry study.

    PubMed

    Coster, Douglas J; Lowe, Marie T; Keane, Miriam C; Williams, Keryn A

    2014-05-01

    To investigate changing patterns of practice of keratoplasty in Australia, graft survival, visual outcomes, the influence of experience, and the surgeon learning curve for endothelial keratoplasty. Observational, prospective cohort study. From a long-standing national corneal transplantation register, 13 920 penetrating keratoplasties, 858 deep anterior lamellar keratoplasties (DALKs), and 2287 endokeratoplasties performed between January 1996 and February 2013 were identified. Kaplan-Meier functions were used to assess graft survival and surgeon experience, the Pearson chi-square test was used to compare visual acuities, and linear regression was used to examine learning curves. Graft survival. The total number of corneal grafts performed annually is increasing steadily. More DALKs but fewer penetrating grafts are being performed for keratoconus, and more endokeratoplasties but fewer penetrating grafts are being performed for Fuchs' dystrophy and pseudophakic bullous keratopathy. In 2012, 1482 grafts were performed, compared with 955 in 2002, translating to a requirement for 264 extra corneal donors across the country in 2012. Comparing penetrating grafts and DALKs performed for keratoconus over the same era, both graft survival (P <0.001) and visual outcomes (P <0.001) were significantly better for penetrating grafts. Survival of endokeratoplasties performed for Fuchs' dystrophy or pseudophakic bullous keratopathy was poorer than survival of penetrating grafts for the same indications over the same era (P <0.001). Visual outcomes were significantly better for penetrating grafts than for endokeratoplasties performed for Fuchs' dystrophy (P <0.001), but endokeratoplasties achieved better visual outcomes than penetrating grafts for pseudophakic bullous keratopathy (P <0.001). Experienced surgeons (>100 registered keratoplasties) achieved significantly better survival of endokeratoplasties (P <0.001) than surgeons who had performed fewer grafts (<100

  6. Candida glabrata endophthalmitis following penetrating keratoplasty in a patient with negative donor rim culture.

    PubMed

    Muzaliha, Mohd Nor; Adil, Hussein; Ibrahim, Mohtar; Shatriah, Ismail

    2010-06-11

    Candida glabrata endophthalmitis following keratoplasty is rare and almost always associated with positive donor rim culture. A 63-year-old patient, diagnosed Fuch's endothelial dystrophy in both eyes underwent a penetrating keratoplasty in his right eye. He had multiple underlying medical problems, which included diabetes mellitus, hypertension, hypoadrenalism on oral dexamethasone and fatty liver secondary to hypertrigliseridemia. He developed multiple suture abscesses, corneal haziness, retrocorneal white plaques and a level of hypopyon two weeks after an uneventful penetrating keratoplasty in his right eye. Cultures of the donor button and the transport media culture were negative. Candida glabrata was isolated successfully from the aqueous and vitreous taps. He was treated with a combination of topical, intracameral, intravitreal and intravenous Amphotericin B. His final visual acuity remained poor due to the haziness of the corneal button. Candida glabrata endophthalmitis following penetrating keratoplasty can occur in negative donor rim and transport media cultures. The growth of the organism is facilitated by the patient's immunocompromised status. Awareness by the ophthalmologists and appropriate choice of antibiotics are mandatory in this challenging condition.

  7. Quality of vision after femtosecond laser-assisted descemet stripping endothelial keratoplasty and penetrating keratoplasty: a randomized, multicenter clinical trial.

    PubMed

    Cheng, Yanny Y Y; van den Berg, Tom J T P; Schouten, Jan S; Pels, Elisabeth; Wijdh, Robert-Jan; van Cleynenbreugel, Hugo; Eggink, Catharina A; Rijneveld, Wilhelmina J; Nuijts, Rudy M M A

    2011-10-01

    To compare the quality of vision (straylight and contrast sensitivity) after femtosecond laser-assisted Descemet stripping endothelial keratoplasty (FS DSEK) and penetrating keratoplasty (PK). Prospective, randomized clinical trial. setting: Multicenter (5 ophthalmic centers in The Netherlands). study population: Eighty eyes of 80 patients with corneal endothelial dysfunction were included and were randomized to FS DSEK or PK. observation procedures: FS DSEK and PK. main outcome measures: Straylight, contrast sensitivity, astigmatism, uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), and visual symptom score. Straylight at 12 months was 1.37 ± 0.2 logarithm of straylight for FS DSEK and 1.46 ± 0.2 logarithm of straylight for PK (P = .151). During 12 months of follow-up, there was a significant improvement of straylight and contrast sensitivity after FS DSEK (P < .001) and PK (P < .001). The change of straylight and contrast sensitivity correlated significantly with the change of BSCVA after FS DSEK (r = -0.645; r = 0.580) and PK (r = -0.370; r = 0.659). The visual symptom score was comparable between the 2 groups during the 12 months of follow-up. Improvement of straylight and contrast sensitivity was significantly correlated with an improvement of BSCVA. Straylight and contrast sensitivity were improved significantly after FS DSEK and were comparable with those after PK, although BSCVA was slightly better in the PK group. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Novel corneal piggyback technique for consecutive intraocular lens implantation and penetrating keratoplasty surgery.

    PubMed

    Matsumoto, Yukihiro; Dogru, Murat; Shimazaki, Jun; Tsubota, Kazuo

    2015-06-01

    To report a novel "piggyback" penetrating keratoplasty technique performed in a patient with severe keratoconus. A 43-year-old man underwent cataract surgery and a new "piggyback" penetrating keratoplasty (PKP) technique in his right eye, as he suffered from severe keratoconus and mature cataract due to severe atopic dermatitis. Under general anesthesia, phacoemulsification and aspiration (PEA), intraocular lens (IOL) implantation, and "piggyback" PKP while avoiding open-sky surgery was performed to prevent serious complications including IOL and vitreous prolapse. This PKP technique had been completed as a totally closed surgery. One year after "piggyback" PKP and cataract surgery, the grafted cornea remained clear and IOL was also well positioned. Best-corrected visual acuity improved from hand motions to 30/100. A novel "piggyback" PKP technique was successfully performed in a patient with severe keratoconus. The new "piggyback" corneal transplantation technique may become an indispensable tool for transplant surgeons who want to improve surgical safety and predictability.

  9. Laser welding in penetrating keratoplasty and cataract surgery of pediatric patients: early results

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Pini, Roberto; Menabuoni, Luca; Malandrini, Alex; Canovetti, Annalisa; Lenzetti, Ivo; Capozzi, Paolo; Valente, Paola; Buzzonetti, Luca

    2013-03-01

    Diode laser welding of ocular tissues is a procedure that enables minimally invasive closure of a corneal wound. This procedure is based on a photothermal effect: a water solution of Indocyanine Green (ICG) is inserted in the surgical wound, in order to stain the corneal tissue walls. The stained tissue is then irradiated with a low power infrared diode laser, delivering laser light through a 300-μm core diameter optical fiber. This procedure enables an immediate closure of the wounds: it is thus possible to reduce or to substitute the use of surgical threads. This is of particular interest in children, because the immediate closure improves refractive outcome and anti-amblyopic effect; moreover this procedure avoids several general anaesthesia for suture management. In this work, we present the first use of diode laser welding procedure in paediatric patients. 5 selected patients underwent cataract surgery (Group 1), while 4 underwent fs-laserassisted penetrating keratoplasty (Group 2). In Group 1 the conventional surgery procedure was performed, while no stitches were used for the closure of the surgical wounds: these were laser welded and immediately closed. In Group 2 the donor button was sutured upon the recipient by 8 single stitches, instead of 16 single stitches or a running suture. The laser welding procedure was performed in order to join the donor tissue to the recipient bed. Objective observations in the follow up study evidenced a perfect adhesion of the laser welded tissues, no collateral effects and an optimal restoration of the treated tissues.

  10. Penetrating keratoplasty restoring vision in an unusual case of corneal opacity following exposure to Euphorbia latex.

    PubMed

    Dutta, Jayanta; Choudhury, Somnath; Lahiri, Kapildeb; Savale, Smruti; Banerjee, Monideepa; Datta, Himadri

    2015-10-01

    The milky sap of the Euphorbia plant is highly toxic and causes inflammation to the skin and eyes. Damage to the eye ranges from superficial epithelial defects, keratoconjunctivitis, mild to moderate corneal edema, anterior uveitis, Descemet membrane folds, raised intraocular pressure and rarely corneal opacity in severe untreated cases. Here we report a case of visual restoration by optical penetrating keratoplasty in a patient with severe corneal opacity following exposure to Euphorbia latex.

  11. Long-term analysis of LASIK for the correction of refractive errors after penetrating keratoplasty.

    PubMed Central

    Hardten, David R; Chittcharus, Anuwat; Lindstrom, Richard L

    2002-01-01

    PURPOSE: To determine the long-term safety and effectiveness of laser-assisted in situ keratomileusis (LASIK) in the treatment of refractive errors following penetrating keratoplasty. METHODS: A retrospective review was done of 57 eyes of 48 patients with anisometropia or high astigmatism who were unable to wear glasses or a contact lens after penetrating keratoplasty and who underwent LASIK for visual rehabilitation. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), and corneal transplant integrity were recorded before surgery as well as up to 60 months after LASIK. RESULTS: The mean follow-up after the LASIK was 21.4 +/- 14.2 months (range, 3-60 months). Mean preoperative spherical equivalent (SE) was -4.19 +/- 3.38 diopters (D). Mean preoperative astigmatism was 4.67 +/- 2.18 D. Preoperative BCVA was 20/40 or better in 42 eyes (74%). At 2 years the mean SE was -0.61 +/- 1.81 D and mean astigmatism was 1.94 +/- 1.35 D for the 28 eyes with follow-up. UCVA was 20/40 or better in 12 eyes (43%), and BCVA was 20/40 or better in 24 eyes (86%) at 2 years. A gain in BCVA of one line or more was seen in eight eyes (29%). Two eyes (7%) had loss of two or more lines of BCVA at 2 years. Nine eyes (16%) developed epithelial ingrowth. Five eyes (9%) in this series had repeat corneal transplants. CONCLUSIONS: LASIK is effective for reducing ametropia after penetrating keratoplasty. Proper patient counseling is necessary because the results of LASIK after penetrating keratoplasty are not as good as, and complications are more frequent than, in eyes with naturally occurring myopia and astigmatism. Complications are especially common in patients with mismatch of the donor and host cornea and in those with poor endothelial cell function. PMID:12545688

  12. Elevated intraocular pressure in the early postoperative period following excimer laser penetrating keratoplasty for keratoconus.

    PubMed

    Gatzioufas, Zisis; Labiris, Georgios; Mauer, Benjamin; Zemova, Elena; Eppig, Timo; Langenbucher, Achim; Seitz, Berthold

    2012-01-01

    To assess the incidence of elevated intraocular pressure (IOP) in the early postoperative period after excimer laser penetrating keratoplasty for keratoconus and reveal potential associations with anterior segment parameters. This prospective, interventional study consisted of 40 patients with keratoconus who were treated with excimer laser penetrating keratoplasty. Corneal pachymetry, anterior chamber depth, anterior chamber volume, and anterior segment angle were measured by Scheimpflug camera preoperatively and 2 months postoperatively. IOP was obtained using Goldmann applanation tonometry. Student's t tests and Pearson correlation were applied. A P value of .05 or less was considered significant. IOP increased from 16.3 ± 3.5 preoperatively to 19.3 ± 5.2 mm Hg postoperatively (P = .007). Significant differences were detected in corneal pachymetry (P < .008), anterior chamber depth (P < .001), and anterior chamber volume (P = .03). Postoperative IOP was significantly correlated with anterior segment angle, anterior chamber depth, and corneal pachymetry. Elevated IOP in the early postoperative period after excimer laser penetrating keratoplasty is significantly correlated with changes in the anterior chamber architecture. Copyright 2012, SLACK Incorporated.

  13. New stroboscopic light source and technique for intraoperative retinal fluorescein angiography during penetrating keratoplasty

    NASA Astrophysics Data System (ADS)

    Krueger, Ronald R.; Morales, Ronald B.; Chong, Lawrence P.; Smith, Ronald E.

    1994-06-01

    We report the development of a new stroboscopic light source system and technique for performing intraoperative fluorescein angiography during penetrating keratoplasty for aphakic or pseudophakic bullous keratopathy. A controllable pulse xenon light source system with a fiber optic endoilluminator probe is used to perform high-quality intraoperative fluorescein angiography during penetrating keratoplasty in pigmented rabbits and human subjects. Following corneal trephination and extraction of the intraocular lens, a temporary Cobo keratoprosthesis is secured while a 20-gauge endoilluminator is inserted into the vitreous cavity through a limbal incision. The endoilluminator is advanced to a retinal illumination area of approximately 3 DD and 10% fluorescein is injected intravenously. A microscope camera coupled to a 50:50 beamsplitter photographs the passage of fluorescein dye while the surgeon maintains an unaltered view through the operating microscope. Angiograms through a keratoprosthesis show excellent contrast and resolution, comparable to standard fluorescein angiography. Fine peripapillary vessels are seen reproducibly and with great detail in the rabbits. All the phases of retinal angiography can be seen, including arteriolar constriction and capillary nonperfusion in one of four human subjects examined. High quality intraoperative fluorescein angiography can be performed in patients undergoing penetrating keratoplasty for aphakic/ pseudophakic bullous keratopathy. With this technology, preexisting retinal disorders such as cystoid macular edema might be identified in the perioperative setting allowing for important management decisions to be made intraoperatively.

  14. Infectious crystalline keratopathy caused by Cladosporium sp. after penetrating keratoplasty: a case report

    PubMed Central

    Stock, Ricardo Alexandre; Bonamigo, Elcio Luiz; Cadore, Emeline; Oechsler, Rafael Allan

    2016-01-01

    Background Infectious crystalline keratopathy is a rare, progressive infection characterized by the insidious progression of branches and crystalline corneal opacities with minimal or no inflammation. This case report describes the evolution of an infectious crystalline keratopathy caused by Cladosporium sp., which developed after tectonic keratoplasty in a patient with a history of ocular trauma. Case presentation A 40-year-old Brazilian male was the victim of firework-induced trauma to the left eye, which resulted in a corneal laceration that could not be sutured as well as a severe traumatic cataract. The patient underwent penetrating keratoplasty and phacoemulsification. During postoperative follow-up, another therapeutic keratoplasty was required because unresponsive infectious keratitis was observed. The infiltrate’s characteristics were suggestive of infectious crystalline keratopathy; in particular, the infiltrate was insidious and progressive, and grayish-white branches appeared in the anterior corneal stroma. As different therapies were administered, inflammatory reactions ranging from mild to severe were observed. The infection was unresponsive to typical antifungal drugs. This lack of response most likely occurred due to steroid treatment and the diffuse corneal spread of an atypical microorganism, which was subsequently identified in culture as Cladosporium sp. After the second therapeutic keratoplasty, the patient’s eye integrity was successfully reestablished. Conclusion This study likely provides the first report describing a case of infectious crystalline keratopathy caused by Cladosporium sp. This case emphasizes the clinical characteristics and outcome of this type of keratitis. PMID:27621671

  15. Comparison of Outcomes in Patients Who Underwent Deep Anterior Lamellar Keratoplasty and Those Converted to Penetrating Keratoplasty

    PubMed Central

    Koçluk, Yusuf; Alyamaç Sukgen, Emine; Burcu, Ayşe

    2017-01-01

    Objectives: To compare clinical outcomes of cases who underwent deep anterior lamellar keratoplasty (DALK) and cases who were converted to penetrating keratoplasty (PKP) from DALK surgery. Materials and Methods: The records of 54 patients for whom DALK surgery was planned and were operated for different diagnoses between March 2013 and June 2015 were retrospectively analyzed. Patients were divided into two groups: group 1 (PKP group) consisted of 23 cases who were converted to PKP due to Descemet’s membrane perforation at any stage of surgery; group 2 (DALK group) consisted of 31 patients whose surgery could be completed as DALK. Preoperative and postoperative follow-up results were evaluated in each group. Results: Corrected distance visual acuity (CDVA) increased in the postoperative period according to baseline in both groups. However, there was no statistically significant difference in the rates of CDVA increase between the groups (p=0.142). The mean astigmatism measured by corneal topography at final examination was 5.8±2.3 diopters in group 1 and 5.4±1.8 diopters in group 2. The difference between groups was not statistically significant (p=0.430). The groups were not statistically different regarding postoperative pachymetry (p=0.453). The grafts in all 54 patients (100%) were clear at final postoperative examination. There were no statistically significant differences between the groups in terms of postoperative complications. Conclusion: Similar clinical outcomes were obtained in our study for patients who underwent DALK and those whose procedure was converted from DALK to PKP. PMID:28405478

  16. Visual rehabilitation using mini-scleral contact lenses after penetrating keratoplasty.

    PubMed

    Rocha, Guilherme Andrade do Nascimento; Miziara, Patrícia Oliveira Braga; Castro, Ana Clara Vieira de; Rocha, Arthur Andrade do Nascimento

    2017-01-01

    To report the visual rehabilitation outcomes and complications of patients fitted with mini-scleral rigid gas-permeable (RGP) contact lenses (mini-SCLs) after penetrating keratoplasty. We retrospectively reviewed 27 eyes (21 patients) that were fitted with mini-SCLs between October 2013 and December 2014. We analyzed demographic data, previous corneal disorders, visual outcomes, interval from keratoplasty to contact lens fitting, topographic and specular microscope data, fitted contact lens parameters, and complications. The patients were divided into two groups according to the elapsed time since surgery: Group A, grafts with <10 years (n=14 eyes); and Group B, grafts with ≥10 years (n=13 eyes). Lens use was discontinued in four eyes, and microbial keratitis developed in one eye during follow-up. No corneal graft rejection was observed. The mean interval between grafting and initial contact lens fitting was 10.6 ± 7.3 years (range: 1-29 years). The most frequent reason for keratoplasty was keratoconus (22 eyes, 81.4%). The mean contact lens-corrected visual acuity (CLCVA) was 0.09 ± 0.12 logMar (range: 0.50-0.00 logMar). The average topographic astigmatism, mean steepest keratometry (Kmax), and average cellularity on specular microscopy were 6.19 ± 3.49 diopters (D), 58.4 ± 7.8 D, and 1,231 ± 723 cells/mm2, respectively. Mini-SCL use allowed successful visual rehabilitation after corneal keratoplasty, particularly in patients who required corrective lenses for low visual acuity and were unable to wear RGP contact lenses. Our results indicate that mini-scleral lenses may be an option for the treatment of corneal irregularities, such as those associated with keratoplasty.

  17. Results of excimer laser penetrating keratoplasty in aphakic eyes.

    PubMed

    Ninios, K; Matoula, P; Szentmary, N; Schirra, F; Seitz, B

    2013-04-01

    Corneal grafting in aphakic eyes is often challenging. We report about the outcome of excimer laser trephination in aphakic eyes. We examined 17 eyes of 17 patients. Diagnosis in 11 eyes was endothelial decompensation and in six, corneal scars. We performed an excimer laser keratoplasty with intraoperative "Flieringa ring" suturing. Follow-up ranged between 3 and 41 (17.6 ± 11.7) months. Main outcome measures included: best-corrected visual acuity (BCVA), intraocular pressure (IOP), topographic astigmatism, corneal refractive power (CRP), central corneal thickness (CCT) and endothelial cell density (ECD). Preoperative BCVA was light perception in two eyes, hand motion in seven, finger counting in one eye, under 20/400 in six eyes and 20/200 in one eye. IOP ranged between 4 and 28 (13.6 ± 5.1) mmHg. Topographic astigmatism ranged from 0.5 to 18.5 (7.0 ± 6.9) dioptres. CRP was between 38 and 59 (46 ± 9) dioptres. CCT was between 404 and 1069 (748 ± 181) μm. Postoperative BCVA was hand motion in five eyes, under 20/400 in two and ranged between 20/200 and 20/20 in ten eyes. IOP ranged between 10 and 40 (18.3 ± 8.5) mmHg. Topographic astigmatism ranged from 0.9 to 13 (5.5 ± 3.2) dioptres. CRP was between 31.9 and 46.7 (42 ± 4.1) dioptres. CCT was between 349 and 820 (552 ± 115.57) μm. ECD was between 592 and 2319 (1674 ± 553) cells/mm(2). Excimer laser trephination can deliver beneficial visual outcomes in most of the aphakic eyes.

  18. Outcomes of Infectious versus Sterile Perforated Corneal Ulcers after Therapeutic Penetrating Keratoplasty in the United States

    PubMed Central

    Rush, Sloan W.

    2016-01-01

    Purpose. To compare the long-term outcomes of infectious versus sterile perforated corneal ulcers after therapeutic penetrating keratoplasty in the United States. Methods. The charts of 45 consecutive eyes that underwent primary therapeutic penetrating keratoplasty for a perforated corneal ulcer at a single center were retrospectively reviewed. The perforated ulcers were classified as infectious or sterile and the underlying demographics, clinical features, and 36-month outcomes were compared among the two groups. Results. Mean follow-up among subjects was 38.6 (±6.9) months. Patients presenting with sterile perforated ulcers were more likely to have a peripheral perforation location (p = 0.0333) and recurrence of the underlying disease condition (p = 0.0321), require adjunctive surgical measures in the immediate postoperative period (p < 0.0001), have reperforation after keratoplasty (p = 0.0079), have worse best corrected visual acuity (p = 0.0130), develop no light perception vision (p = 0.0053), and require enucleation/evisceration (p = 0.0252) when compared to the infectious perforated ulcer group. Conclusions. Sterile perforated corneal ulcers have a worse prognosis and may be more frequent than those caused by infectious disease in the United States compared to the developing world. PMID:28070416

  19. Endophthalmitis by Pseudomonas aeruginosa. after penetrating keratoplasty, case report with an epidemiological investigation.

    PubMed

    Blanco, Claudia; Núñez, María X

    2010-01-01

    An endophthalmitis following penetrating keratoplasty by Pseudomonas aeruginosa is a devasting case with very poor visual outcomes. To determine the origin of an infection after a penetrating keratoplasty. After an endophthalmitis an epidemiological study was undertaken with the approval of the ethics committee and support of a medical team comprised of an epidemiologist, infectologist, bacteriologist and ophthalmologists specializing in cornea. Factors that may have contributed to the risk of infection were assessed, for example, the processing and preservation of the cornea in the moment of the extraction, the characteristics of the donor, recipient and infecting bacterium, as well as the details pertaining to the surgical operation. No risks factors were found in the institution, in the eye bank facilities, in the donor or in the receptor. However, sterile technique could not be guaranteed in the morgue where the corneal extraction occurred, and other isolated cases of endophthalmitis post-keratoplasty had been documented involving tissues from the same morgue that had been processed by two eye banks in the same city. Characteristics of the multi-resistant Pseudomonas sp. demonstrated its origin from a hospital environment due to its previous exposure to a variety of antibiotics. Corneal extraction site must guarantee an antiseptic preparation and aseptic tissue donor recuperation; although in this study it was not feasible to accurately establish the infection source, all of the findings led to suspect a possible contamination at the morgue.

  20. Top-hat shaped corneal trephination for penetrating keratoplasty using the femtosecond laser: a histomorphological study.

    PubMed

    Kook, Daniel; Derhartunian, Victor; Bug, Reinhold; Kohnen, Thomas

    2009-08-01

    To evaluate a novel technique for penetrating keratoplasty (PK) with the use of a new software algorithm for the femtosecond laser, designed to create penetrating cuts in a top hat configuration. Consecutive histomorphological case series. Twelve eyes of 12 patients underwent penetrating keratoplasty by means of a 60-kHz femtosecond laser (IntraLase, Irvine, California) with a software specifically developed for corneal surgery. Of the 12 patients, the reason for keratoplasty was keratoconus in 4 patients, bullous keratopathy in 6 patients, keratotorus in 1 patient, and status post chemical burn in 1 patient. A new software was used to create penetrating cuts in a top-hat-shaped configuration. In all cases, cutting parameters were identical in all donor and corresponding host corneas: 7.0 mm diameter of the anterior side cut, 8.5-8.7 mm diameter of the posterior side cut, and a depth of 300 microm for the lamellar cut. In all cases, a complete penetrating cut with the laser in the host cornea was not intended intraoperatively. Complete penetration was performed subsequently and manually with a diamond knife because of logistic conditions. Trephined corneoscleral rings and button corneas were analyzed macroscopically and histologically to determine cut quality. All procedures were performed without any complications. With application of appropriate combinations of pulse energy and spacing, trephination took less than 200 seconds. Macroscopic examination and histology of donor and recipient specimens showed a straight, smooth cut with perpendicular edges in all donor buttons. No corneal edema and no visible damage to the keratocyte nuclei were found. At the region of manual dissection, a small stromal tissue-tag was present in parts of the circumference in all donor buttons. No evidence of any cut complication was noted. Top-hat-shaped penetrating keratoplasty using the IntraLase femtosecond laser enables a quick and sufficient trephination of both human donor and

  1. Excimer laser "corneal shaping": a new technique for customized trephination in penetrating keratoplasty. First experimental results in rabbits.

    PubMed

    Schmitz, Klaus; Schreiber, Wolfram; Behrens-Baumann, Wolfgang

    2003-05-01

    The aim of the presented experimental work was to develop a technique for congruent trephination of donor and recipient corneas in free form using a 193-nm excimer laser and to study the clinical follow-up after the application of the technique in a rabbit model. In 12 New Zealand White rabbits homologous penetrating keratoplasty was performed. Trephination of donor buttons and recipient beds was achieved in six animals by conventional mechanical trephination and in six by excimer laser trephination with a guided laser beam in a non-circular geometry. The surgical procedure and its applicability to human subjects were evaluated and the postoperative clinical course was followed for 6 months. The surgical procedure of full-thickness excimer laser trephination could be performed reproducibly in the animal model both for dissection of the donor buttons and for preparation of the recipient beds. Keratoplasty was performed with kidney-shaped transplants after trephination in free form with the guided laser beam. Postoperative clinical follow-up did not show any differences between the two trephination groups that could be related to the applied trephination technique. After 6 months we observed well-adapted and clear corneal grafts, kidney-shaped in the excimer trephination group and circular in the mechanical trephination group. No side effects on the crystalline lens and the central retina could be clinically observed following excimer laser trephination. We present the first experimental study of keratoplasty with freely selected transplant geometry and perfect congruence of donor button and recipient bed. The application of this technique in certain corneal disorders in humans will offer improved treatment options in the future.

  2. Endothelial cell loss and visual outcome of deep anterior lamellar keratoplasty versus penetrating keratoplasty: a randomized multicenter clinical trial.

    PubMed

    Cheng, Yanny Y Y; Visser, Nienke; Schouten, Jan S; Wijdh, Robert-Jan; Pels, Elisabeth; van Cleynenbreugel, Hugo; Eggink, Catharina A; Zaal, Michel J W; Rijneveld, Wilhelmina J; Nuijts, Rudy M M A

    2011-02-01

    To compare endothelial cell (EC) loss, visual and refractive outcomes, and complications after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK). Randomized, multicenter clinical trial. Fifty-six eyes of 56 patients with a corneal stromal pathology not affecting the endothelium were randomized to DALK or PK. The DALK procedure was performed according to Anwar's big-bubble technique. Patients underwent an ophthalmic examination preoperatively and 3, 6, and 12 months postoperatively. Endothelial cell loss, refractive and topographic astigmatism, spherical equivalent, uncorrected visual acuity, and best spectacle-corrected visual acuity (BSCVA) were measured, and complications were recorded. Endothelial cell loss was significantly higher after PK compared with DALK procedures performed without perforation of Descemet's membrane (12 months: 27.7% ± 11.1% vs. 12.9% ± 17.6%). The BSCVA was significantly better in the PK group at 3 and 6 months after surgery but was not significantly different 12 months after surgery (0.39 ± 0.3 logarithm of the minimum angle of resolution [logMAR] in DALK and 0.31 ± 0.3 logMAR in PK). At 12 months postoperatively, refractive and topographic astigmatism in the DALK and PK groups were -3.37 ± 2.3 diopters (D) and -3.76 ± 2.1 D (P = 0.53), and 3.57 ± 2.3 D and 4.16 ± 2.0 D (P = 0.34), respectively. (Micro)perforation of the Descemet's membrane occurred in 32% (9/28) of the DALK eyes, and 18% (5/28) of the patients required conversion to PK. Endothelial cell loss was not significantly different between DALK and PK when cases with perforation of Descemet's membrane were included in the (intention-to-treat) analysis (12 months: 19.1 ± 21.6 vs. 27.7 ± 11.1 P = 0.112). Rejection episodes were reported in 1 patient in the DALK group (epithelial rejection) and 3 patients in the PK group (all endothelial rejections). No graft failure occurred. One year after DALK performed without perforation of Descemet

  3. Comparison of visual and topographic outcomes of deep-anterior lamellar keratoplasty and penetrating keratoplasty in keratoconus

    PubMed Central

    Yüksel, Bora; Kandemir, Baran; Uzunel, Umut Duygu; Çelik, Ozan; Ceylan, Sezgin; Küsbeci, Tuncay

    2017-01-01

    AIM To compare visual, surgical and topographic outcomes of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) for keratoconus (KC). METHODS In this multicenter, prospective, randomized clinical trial 76 eyes of 71 KC patients operated between January 2011 and July 2014 in 2 tertiary referral hospitals were included. Consecutive patients were alternately selected to receive one of the two surgical methods. Thirty eight eyes underwent DALK with the big-bubble technique and 38 eyes underwent PK. RESULTS Mean best spectacle corrected visual acuity (BSCVA) at the first postoperative week (P=0.012) and the first postoperative month (P<0.001) was statistically significantly higher in DALK group. The mean BSCVA at 12mo was not significantly different for DALK (0.30±1.99 logMAR) versus PK (0.40±0.33 logMAR) (P=0.104). The 76.3% of the eyes had a BSCVA over 0.5 in DALK and 47.4% in PK group (P=0.009). The 7.9% of the eyes had a BSCVA of 1.0 in DALK and 5.3% in PK group (P=0.644). Mean spherical equivalent was -2.94 D in DALK and -3.09 D in PK group. Mean topographic astigmatism was 4.62 D and 4.18 D respectively. Regular topographic patterns were observed in 31 (81.6%) of DALK and 29 (76.3%) of PK (P=0.574). The most frequent topographic pattern was oblate asymmetric bow tie, seen in 39.5% in DALK and 23.7% in PK. CONCLUSION Big bubble DALK provides an earlier visual improvement compare to PK. However, visual and topographic outcomes are similar to those in PK at 1y. Postoperative complications including rejection and intraocular pressure elevation are more frequent in PK. DALK is a safer alternative to PK for KC. However, intraoperative perforation of the Descemet's membrane is a significant complication. PMID:28393029

  4. Eye-tracker-guided non-mechanical excimer laser assisted penetrating keratoplasty.

    PubMed

    Janunts, Edgar; Schirra, Frank; Szentmáry, Nora; Seitz, Berthold; Langenbucher, Achim

    2013-03-18

    The purpose of the study was to implement a new eye tracking mask which could be used to guide the laser beam in automated non-mechanical excimer laser assisted penetrating keratoplasty. A new trephination mask design with an elevated surface geometry has been proposed with a step formation between conical and flat interfaces. Two recipient masks of 7.5/8.0 mm have been manufactured and tested. The masks have outer diameter of 12.5 mm, step formation at 10.5 mm, and slope of conical surfaces 15°. Its functionality has been tested in different lateral positions and tilts on a planar surface, and pig eye experiments. After successful validation on porcine eyes, new masks have been produced and tested on two patients. The build-in eye tracking software of the MEL 70 was always able to capture the masks. It has been shown that the unwanted pigmentation/pattern induced by the laser pulses on the mask surface does not influence the eye-tracking efficiency. The masks could be tracked within the 18 × 14 mm lateral displacement and up to 12° tilt. Two patient cases are demonstrated. No complications were observed during the surgery, although it needs some attention for aligning the mask horizontally before trephination. Stability of eye tracking masks is emphasized by inducing on purpose movements of the patient head. Eye-tracking-guided penetrating keratoplasty was successfully applied in clinical practice, which enables robust tracking criteria within an extended range. It facilitates the automated trephination procedure of excimer laser-assisted penetrating keratoplasty.

  5. Eye-Tracker-Guided Non-Mechanical Excimer Laser Assisted Penetrating Keratoplasty

    PubMed Central

    Janunts, Edgar; Schirra, Frank; Szentmáry, Nora; Seitz, Berthold; Langenbucher, Achim

    2013-01-01

    Purpose: The purpose of the study was to implement a new eye tracking mask which could be used to guide the laser beam in automated non-mechanical excimer laser assisted penetrating keratoplasty. Materials and methods: A new trephination mask design with an elevated surface geometry has been proposed with a step formation between conical and flat interfaces. Two recipient masks of 7.5/8.0 mm have been manufactured and tested. The masks have outer diameter of 12.5 mm, step formation at 10.5 mm, and slope of conical surfaces 15°. Its functionality has been tested in different lateral positions and tilts on a planar surface, and pig eye experiments. After successful validation on porcine eyes, new masks have been produced and tested on two patients. Results: The build-in eye tracking software of the MEL 70 was always able to capture the masks. It has been shown that the unwanted pigmentation/pattern induced by the laser pulses on the mask surface does not influence the eye-tracking efficiency. The masks could be tracked within the 18 × 14 mm lateral displacement and up to 12° tilt. Two patient cases are demonstrated. No complications were observed during the surgery, although it needs some attention for aligning the mask horizontally before trephination. Stability of eye tracking masks is emphasized by inducing on purpose movements of the patient head. Conclusion: Eye-tracking-guided penetrating keratoplasty was successfully applied in clinical practice, which enables robust tracking criteria within an extended range. It facilitates the automated trephination procedure of excimer laser-assisted penetrating keratoplasty. PMID:23507821

  6. Evaluation of stability and biocompatibility of PHEMA-PMMA keratoprosthesis by penetrating keratoplasty in rabbits

    PubMed Central

    Hwang, Yawon

    2016-01-01

    Artificial corneas have been developed as an alternative to natural donor tissue to replace damaged or diseased corneas. This study was conducted to evaluate the stability and biocompatibility of PHEMA-PMMA [poly (2-hydroxyl methacrylate)-poly (methyl methacrylate)] keratoprostheses in rabbits following penetrating keratoplasty. Sixteen male New Zealand White rabbits aged 16 weeks were divided into three groups. Group I and group II contained six rabbits each, while the control group had four rabbits. Experimental surgery was conducted under general anesthesia. The cornea was penetrated using an 8 mm diameter biopsy punch. In group I (core 5 mm & skirt 3 mm) and group II (core 6 mm & skirt 2 mm), the keratoprosthesis was placed into the recipient full thickness bed and sutured into position with double-layer continuous. In the control group, corneal transplantation using normal allogenic corneal tissue was performed with the same suture method. After four and eight weeks, keratoprosthesis devices were evaluated by histopathological analysis of gross lesions. Post-operative complications were observed, such as extrusion and infection in experimental groups. Most corneas were maintained in the defect site by double-layer continuous suture materials for 4 weeks and kept good light transmission. However, most artificial cornea were extruded before 8 weeks. Overall, combined PHEMA and PMMA appears to have sufficient advantages for production of artificial corneas because of its optical transparency, flexibility and other mechanical features. However, the stability and biocompatibility were not sufficient to enable application in humans and animals at the present time using penetrating keratoplasty. Further studies are essential to improve the stability and biocompatibility with or without other types of keratoplasty. PMID:28053610

  7. In vivo confocal microscopy in recurrent granular dystrophy in corneal graft after penetrating keratoplasty.

    PubMed

    Traversi, Claudio; Martone, Gianluca; Malandrini, Alex; Tosi, Gian Marco; Caporossi, Aldo

    2006-11-01

    Two case reports of recurrent granular dystrophy in corneal grafts after penetrating keratoplasty are presented. Slit-lamp examination and confocal microscopy (HRT II) were performed in two patients with recurrent granular dystrophy. All confocal microscopic findings of granular dystrophy were evaluated in the graft. Dystrophic lesions of the donor cornea presented the same confocal microscopic aspects in both eyes, and were similar to granular dystrophy lesions. Confocal microscopy is an imaging method that may provide new information on corneal microanatomy in dystrophies. It may be particularly useful in improving the early diagnosis of dystrophic lesions in corneal grafts.

  8. Microcyclosporella mali: a novel fungal keratitis in a post-penetrating keratoplasty patient

    PubMed Central

    Vyas, Neil; Munir, Wuqaas

    2015-01-01

    An 86-year-old woman underwent penetrating keratoplasty for pseudophakic bullous keratopathy and presented with an acute corneal ulcer thereafter. Examination demonstrated a fluffy white infiltrate and epithelial defect with subsequent endothelial plaque formation and anterior chamber inflammation. The ulcer was cultured, and fortified topical vancomycin and tobramycin were initiated but failed to significantly improve the clinical course. Cultures were ultimately positive for fungus Microcyclosporella mali that responded well to topical natamycin with stabilisation of the ulcer after 6 weeks of topical therapy. This is the first reported case of fungal keratitis due to M. mali. PMID:25725025

  9. Excimer versus Femtosecond Laser Assisted Penetrating Keratoplasty in Keratoconus and Fuchs Dystrophy: Intraoperative Pitfalls

    PubMed Central

    El-Husseiny, Moatasem; Seitz, Berthold; Akhmedova, Elena; Szentmary, Nora; Hager, Tobias; Tsintarakis, Themistoklis

    2015-01-01

    Purpose. To assess the intraoperative results comparing two non-mechanical laser assisted penetrating keratoplasty approaches in keratoconus and Fuchs dystrophy. Patients and Methods. 68 patients (age 18 to 87 years) with keratoconus or Fuchs dystrophy were randomly distributed to 4 groups. 35 eyes with keratoconus and 33 eyes with Fuchs dystrophy were treated with either excimer laser ([Exc] groups I and II) or femtosecond laser-assisted ([FLAK] groups III and IV) penetrating keratoplasty. Main intraoperative outcome measures included intraoperative decentration, need for additional interrupted sutures, alignment of orientation markers, and intraocular positive pressure (vis a tergo). Results. Intraoperative recipient decentration occurred in 4 eyes of groups III/IV but in none of groups I/II. Additional interrupted sutures were not necessary in groups I/II but in 5 eyes of groups III/IV. Orientation markers were all aligned in groups I/II but were partly misaligned in 8 eyes of groups III/IV. Intraocular positive pressure grade was recognized in 12 eyes of groups I/II and in 19 eyes of groups III/IV. In particular, in group III, severe vis a tergo occurred in 8 eyes. Conclusions. Intraoperative decentration, misalignment of the donor in the recipient bed, and need for additional interrupted sutures as well as high percentage of severe intraocular positive pressure were predominantly present in the femtosecond laser in keratoconus eyes. PMID:26483974

  10. Femtosecond Laser-Assisted Tuck-In Penetrating Keratoplasty for Advanced Keratoglobus With Endothelial Damage.

    PubMed

    Alió Del Barrio, Jorge L; Al-Shymali, Olena; Alió, Jorge L

    2017-09-01

    To describe the outcomes of femtosecond laser-assisted tuck-in penetrating keratoplasty as a single-step surgical procedure for visual and anatomical rehabilitation of patients with severe keratoglobus (KTG) and endothelial damage. Two eyes of a 7-year-old patient with bilateral severe KTG and previous corneal hydrops were operated. Assisted by the femtosecond laser, both donor and recipient corneas were prepared. An 8.5-mm full-thickness donor tissue with a peripheral partial-thickness rim of 1.25 mm was sutured into an 8.5-mm recipient bed with a previously dissected intralamellar peripheral pocket up to the limbus. The graft was secured with 16 interrupted 10-0 nylon sutures and the peripheral donor rim tucked into the host stromal pocket. Six months after surgery, both grafts remained healthy and clear. One eye developed mild postoperative ocular hypertension. No intraoperative or other postoperative complications were observed. Corrected distance visual acuity was 20/50 in both eyes, with complete functional rehabilitation of the patient. Restoration of the peripheral corneal thickness was observed in the pachymetric map. Femtosecond laser-assisted tuck-in penetrating keratoplasty can provide excellent anatomical and functional rehabilitation of patients with severe KTG and endothelial damage, through a single-step surgical procedure and a single donor cornea per eye. The femtosecond laser permits accurate dissection of these already thin corneas without inadvertent perforation risk.

  11. Closed-system phacoemulsification and posterior chamber implant combined with penetrating keratoplasty.

    PubMed

    Malbran, E S; Malbran, E; Buonsanti, J; Adrogué, E

    1993-06-01

    The main intraoperative difficulties of performing a procedure combining open-sky extracapsular cataract extraction, implantation of posterior chamber intraocular lens (PC-IOL), and penetrating keratoplasty ("triple procedure"), most frequently caused by the uncompensated posterior pressure created when the cornea is open, include incomplete capsulorhexis, incomplete aspiration-irrigation of the cortex, uncertain placing of the IOL, posterior capsule rupture, choroidal effusion, and even expulsive hemorrhage. We recommend a two-step procedure that eliminates these problems: The first step begins with removal of epithelium, half-thickness trephining of the cornea, and capsulorhexis; proceeds through phacoemulsification and aspiration-irrigation; and ends with implantation of the PC-IOL, using a pressurized system. The second step is penetrating keratoplasty. In the six cases undergoing this procedure, none of these complications developed or even tended to develop. Although the follow up in these six cases is very short (from 1 to 6 months), the advantage of the technique is that it effectively precludes the above mentioned intraoperative complications, which could affect late results.

  12. Inadequacy of a polyester (Mersilene) suture for the reduction of astigmatism after penetrating keratoplasty.

    PubMed Central

    Bertram, B A; Drews, C; Gemmill, M; Guell, J; Murad, M; Waring, G O

    1990-01-01

    Through two prospective studies, we evaluated the use of polyester (Mersilene) sutures in penetrating keratoplasty. Study 1 was a randomized comparison of combined running and interrupted Mersilene and nylon sutures (n = 45). Study 2 was a case series of single running Mersilene with postoperative adjustment of suture tension to manage astigmatism (n = 23). Study 1 demonstrated that Mersilene interrupted sutures were 5.5 times more likely to have handling-related complications compared to nylon (P = 0.01); in addition, they were 3 times as likely to have tissue-related complications as nylon interrupted sutures (P = 0.16). Study 2 demonstrated a complication rate of 69% when Mersilene was used as a single adjustable running suture. At 6 months postoperatively, the median refractive astigmatism for the adjustable cases was 3.37 D (mean, 4.03 +/- 2.37 D). Eyes in Study 2 with significant suture-related complications were 2.85 times more likely to have greater than 4 D of refractive astigmatism than were eyes without suture-related complications. We concluded that Mersilene is an undesirable suture for use in penetrating keratoplasty. PMID:2095023

  13. Long-term rejection incidence and reversibility after penetrating and lamellar keratoplasty.

    PubMed

    Guilbert, Emmanuel; Bullet, Julien; Sandali, Otman; Basli, Elena; Laroche, Laurent; Borderie, Vincent M

    2013-03-01

    To identify risk factors for corneal graft rejection and rejection irreversibility. Retrospective cohort study. setting: Institutional. patients: A total of 1438 consecutive eyes of 1438 patients who underwent corneal transplantation for optical indication at the Centre Hospitalier National d'Ophtalmologie des XV-XX, Paris, France, between December 1992 and December 2010 were studied. Surgical technique was penetrating keratoplasty (PK) in 1209 cases, anterior lamellar keratoplasty (ALK) in 165 cases, and Descemet stripping with endothelial keratoplasty in 64 cases. main outcome measures: Cumulative incidence of rejection episodes and rejection irreversibility rate. A total of 299 cases of rejection episodes were identified, of which 145 (48.5%) were irreversible after treatment. In multivariate analysis, the cumulative incidence of rejection episodes was influenced by recipient age (P = .00002), recipient rejection risk (P = .0003), lens status (P = .00003), and surgical group (P = .035). A higher incidence of rejection episodes was observed in young patients (<20 years) and patients aged from 41 to 50, high-risk recipients, aphakic eyes and eyes with anterior chamber intraocular lens, and eyes with PK (compared with eyes with ALK). Rejection episodes were more likely to be irreversible for high-risk recipients (P = .02), for eyes with preoperative hypertony (P = .009), and for eyes with poor visual acuity at presentation (P = .002). Recipient rejection risk and surgical group are the main risk factors for rejection as they both influence the incidence of rejection and the reversibility rate. Recipient age and lens status are predictive factors for the occurrence of rejection. Preoperative hypertony is a predictive factor for rejection irreversibility. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. [Keratoplasty in keratoglobus].

    PubMed

    Alberth, B

    1980-01-01

    In keratoglobus penetrating keratoplasty cannot be performed because the recipient cornea is too thin. The author reports on the three keratoplasties with traction (after Malbran) performed by him and on the results.

  15. Long-term follow-up of astigmatic keratotomy for corneal astigmatism after penetrating keratoplasty.

    PubMed

    Böhringer, Daniel; Dineva, Nina; Maier, Philip; Birnbaum, Florian; Kirschkamp, Thomas; Reinhard, Thomas; Eberwein, Philipp

    2016-11-01

    To report the long-term stability of paired arcuate corneal keratotomies (AKs) in patients with high regular postpenetrating keratoplasty astigmatism. Retrospective chart review of best-corrected visual acuity, refraction and keratometric values of 41 eyes with AK between 2003 and 2012. Magnitude of median target induced astigmatism vector was 9.2 dioptres (Dpt). We reached a median magnitude of surgically induced astigmatism vector of 9.81 Dpt and a median magnitude of difference vector of 5.5 Dpt. In keratometry, we achieved a net median astigmatism reduction by 3.3 Dpt. The average correction index was 1.14, showing a slight overcorrection. Irregularity of keratometric astigmatism increased by 0.6 Dpt, and spherical equivalent changed by 1.75 Dpt. Monocular best spectacle corrected visual acuity increased from preoperatively 20/63 (0.5 logMAR) to 20/40 (0.3 logMAR) postoperatively. Median gain on the ETDRS chart was two lines. Long-term follow-up showed a median keratometric astigmatic increase by 0.3 Dpt per year. Arcuate corneal keratotomies is a safe and effective method to reduce high regular corneal astigmatism following penetrating keratoplasty but has limited predictability. The long-term follow-up shows an increase of keratometric astigmatism by 0.3 Dpt/year, equalizing the surgical effect after 10 years. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  16. Sulcus fixated injectable toric intraocular lens to correct astigmatism following penetrating keratoplasty in a pseudophakic eye

    PubMed Central

    Srinivasan, Sathish; Lyall, Douglas; Watt, John

    2010-01-01

    A 56-year-old Caucasian male was referred to the corneal service for the management of post penetrating keratoplasty (PK) astigmatism in his right eye. He had also previously undergone trabeculectomy and cataract surgery in the same eye. Corneal topography showed high postoperative astigmatism of 8.74 dioptres. He was intolerant to contact lens wear and could not tolerate spectacle correction due to high anisometropia. He proceeded to undergo a secondary ‘piggyback’ toric intraocular lens (IOL) insertion procedure with an improvement in his best corrected visual acuity to 6/9. With the decrease in anisometropia he was able to tolerate a full spectacle correction. We report the use of a new injectable sulcus fixated toric piggyback IOL for the correction of post PK astigmatism in a pseudophakic eye. To the best of our knowledge this is the first report on the use of this new ‘add on’ IOL for this clinical condition.

  17. Penetrating keratoplasty for treatment of corneal protrusion in a great horned owl (Bubo virginianus).

    PubMed

    Andrew, Stacy E; Clippinger, Tracy L; Brooks, Dennis E; Helmick, Kelly E

    2002-09-01

    A young adult great horned owl (Bubo virginianus) was examined following presumed trauma. The owl had soft tissue injury to its left wing as well as corneal protrusion, lens subluxation, and iridodialysis of the right eye. The bird's eye was treated surgically with a large, rectangular penetrating keratoplasty. Following escape from housing, the bird was found with partial wound dehiscence and iris prolapse 12 days post operation. Surgical repair was performed and healing progressed for 14 days, at which time the transplant dehisced and the globe was exenterated. The patient rehabilitated well until escaping from its cage again 4 weeks later, at which time it sustained an open comminuted humeral fracture and was euthanized.

  18. Development of retrocorneal membrane following pig-to-monkey penetrating keratoplasty.

    PubMed

    Lee, Whayoung; Mammen, Alex; Dhaliwal, Deepinder K; Long, Cassandra; Miyagawa, Yuko; Ayares, David; Cooper, David K C; Hara, Hidetaka

    2017-01-01

    Recent reports of long-term survival after wild-type (WT) pig-to-monkey corneal xenotransplantation are encouraging. We experienced the rapid development of retrocorneal membranes, a rare complication after corneal allotransplantation (although seen in infants and young children). The original specific aim of the study was to determine the factors associated with successful (young) pig corneal transplantation in monkeys. However, when it was obvious that retrocorneal membranes rapidly developed, our aims became to determine the factors involved in its development after both WT and Genetically engineered (GE ) pig corneal xenotransplantation and to investigate the characteristics of the retrocorneal membrane. Rhesus monkeys were recipients of penetrating keratoplasty using WT and GE pigs (n=2, respectively, 1-3 months old). Local/systemic steroids were administered for 3 months. Grafts were evaluated by slit lamp for corneal transparency, edema, and neovascularization. Hematoxylin and eosin, Masson trichrome staining, and immunohistochemical analysis were performed. Gal staining was also carried out to distinguish the origin of the membrane. All penetrating keratoplasty recipients developed fibrous retrocorneal membranes in the early post-transplantation period, regardless of whether the graft was from a WT or GE pig. There were no features of rejection, with no cell infiltrate in the graft or anterior chamber during the three-month follow-up. There was no difference in the clinical course between the two groups (WT or GE corneas). Immunohistochemistry indicated that the retrocorneal membranes were CK negative, α-SMA positive, and vimentin positive, suggesting that they were of fibrous (keratocytic) origin. Also, the membrane was Gal positive, suggesting that it is derived from pig cornea. Following pig-to-monkey corneal xenotransplantation, we report that retrocorneal membranes are derived from donor pig keratocytes. Prevention of retrocorneal membranes will be

  19. Efficacy of Chandelier Illumination for Combined Cataract Operation and Penetrating Keratoplasty

    PubMed Central

    Hariya, Takehiro; Uematsu, Megumi; Meguro, Yasuhiko; Kobayashi, Wataru; Nishida, Kohji; Nakazawa, Toru

    2015-01-01

    Purpose: The aim of this study was to describe a method for non–open-sky continuous curvilinear capsulorhexis (CCC) with chandelier retroillumination for penetrating keratoplasty triple procedure and report its effectiveness in decreasing intraoperative complications and enabling successful primary intraocular lens (IOL) insertion in patients with moderate or dense central corneal opacities. Methods: Seventeen eyes of 17 patients were enrolled in this study, divided into a chandelier group, including 7 eyes of 7 patients, and a nonchandelier group, including 10 eyes of 10 patients. In each group, time to achieve CCC (in seconds), open-sky time (in seconds), and operation time (in minutes) were measured, and the rates of successful CCC completion, rupture of the posterior capsule or zonule of Zinn, and successful IOL insertion were recorded. Results: CCC time was not significantly different in both groups. In the chandelier group, however, open-sky time and operation time were significantly shorter than in the nonchandelier group (1429 ± 67 vs. 2016 ± 354 seconds, and 90.4 ± 3.5 vs. 108.9 ± 10.3 minutes, respectively). In the chandelier group, the rate of successful CCC completion was significantly higher than in the nonchandelier group (86% vs. 30%). The rates of posterior capsule or zonule of Zinn rupture and successful IOL insertion were not significantly different (14% vs. 40%, 14% vs. 10%, and 86% vs. 70%, respectively). Conclusions: Non–open-sky CCC with chandelier illumination has many advantages for penetrating keratoplasty triple procedure compared with open-sky CCC without chandelier illumination. PMID:25564335

  20. Corneal graft curvature change after relaxing incisions for post-penetrating keratoplasty astigmatism.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad A

    2012-09-01

    To evaluate change in graft steepness after graft refractive surgery (GRS) consisting of relaxing incisions with or without counterquadrant compression sutures and discover the existing influential factors. In this retrospective study, 78 eyes of 76 patients who had received penetrating keratoplasty for keratoconus underwent GRS because of high post-penetrating keratoplasty astigmatism. Any shift in graft curvature was calculated using the keratometric coupling ratio (CR; the ratio of flattening of the incised meridian to steepening of the opposite meridian). Multiple regression analysis was used to investigate the possible effect of age, graft curvature, number of incisions, use of compression sutures, achieved vector astigmatic correction, and total arc length on CR. Mean patient age was 30.1 ± 10.3 years and mean follow-up period after GRS was 40.1 ± 29.0 months. There was a significant increase in average keratometry from 44.79 ± 2.08 diopters (D) preoperatively to 45.65 ± 1.86 D postoperatively (P < 0.001). Mean keratometric CR was 0.62 ± 1.09. Keratometric CR was significantly associated with patient age (R = 0.53, P = 0.04) and preoperative average keratometry (R = 0.61, P = 0.02). However, keratometric CR failed to show any significant correlation with other variables. A significant increase in graft steepening occurred after GRS, averaging 0.86 D. When both GRS and cataract extraction or phakic intraocular lens implantation are indicated, a staged approach (first GRS followed by phacoemulsification, for example) is advocated to calculate intraocular lens power with accuracy.

  1. Intra-individual variability of penetrating keratoplasty outcome after excimer laser versus motorized corneal trephination.

    PubMed

    Szentmáry, Nóra; Langenbucher, Achim; Naumann, Gottfried O H; Seitz, Berthold

    2006-10-01

    To assess the intra-individual variability of outcomes after penetrating keratoplasty by comparing mechanical and nonmechanical corneal trephination. Fifteen patients (30 eyes, 16 with keratoconus and 14 with Fuchs' dystrophy; median age at penetrating keratoplasty 56.3/53.5 years) were assessed whose trephination was performed using a motor trephine in one eye and the 193-nm excimer laser (MEL 60, Carl Zeiss-Meditec) in the other eye by one experienced surgeon. Subjective refractometry, standard keratometry, and corneal topography were used to assess best spectacle-corrected visual acuity (BSCVA); spherical equivalent refraction; keratometric and topographic central corneal power; refractive, keratometric, and topographic astigmatism; surface regularity index; surface asymmetry index; and potential visual acuity preoperatively, before first suture removal (at 1 year), and at last available follow-up after final suture removal but before additional surgery (1.3 and 1.9 years, respectively). Before first suture removal BSCVA was significantly higher (0.7 vs 0.5; P=.008) after excimer laser trephination. At the end of follow-up, refractive/ keratometric/topographic astigmatism (2.20/2.10/2.40 diopters [D] vs 5.00/6.00/7.10 D) and surface regularity index (0.8 vs 1.1) were significantly lower (P=.02, P=.005, P=.01, and P=.03, respectively) and potential visual acuity was significantly higher (0.9/0.6; P=.02) after excimer laser trephination. During long-term follow-up, all-sutures-out postkeratoplasty astigmatism and surface regularity are superior in the eye where nonmechanical excimer laser was applied in contrast to the fellow eye with motor trephination in the same individual.

  2. Temporary use of a customized, glued-on hard contact lens before penetrating keratoplasty for descemetocele or corneal perforation.

    PubMed

    Kobayashi, Akira; Shirao, Yutaka; Segawa, Yasunori; Kawasaki, Kazuo; Tanahashi, Toshiro; Komata, Miki; Deguchi, Hiroko; Tagawa, Kosaku; Tseng, Scheffer C G

    2003-01-01

    Descemetocele or corneal perforation makes it difficult to perform penetrating keratoplasty (PKP). To circumvent this difficulty, a polymethylmethacrylate hard contact lens with a diameter of 4.0 mm was customized and applied to the cornea with tissue adhesive prior to PKP in three patients, one with corneal perforation and two with descemetoceles. The results showed that this modified method facilitated trephination during PKP without complications in all three patients, suggesting that it may be applicable to other similar clinical situations.

  3. Penetrating keratoplasty using femtosecond laser-enabled keratoplasty with zig-zag incisions versus a mechanical trephine in patients with keratoconus.

    PubMed

    Gaster, Ronald N; Dumitrascu, Oanna; Rabinowitz, Yaron S

    2012-09-01

    This paper will compare the visual outcomes of two different penetrating keratoplasty (PKP) techniques in patients with keratoconus. It is a retrospective comparative surgical case series of 116 keratoconus patients (137 eyes) who had PKP at the Cornea Eye Institute, Beverly Hills, California, USA. 56 keratoconus patients (66 eyes) underwent femtosecond laser-enabled keratoplasty (FLEK) with a zig-zag incision configuration. Their visual parameters were compared with those of 60 patients (71 eyes) who had traditional blade mechanical trephination PKP. The range of follow-up was between 3 and 6 months. The main outcome measures included uncorrected visual acuity and best spectacle-corrected visual acuity (BSCVA), manifest refractive spherical equivalent and topographically determined astigmatism. BSCVA was significantly better as early as 3 months postoperatively (p=0.001) in the FLEK group. Visual recovery to 20/40 after 3 months was significantly better in the FLEK group (p<0.001). Topographic astigmatism was lower in the FLEK group, but the difference between the two groups reached significance only at 3 months of follow-up (p=0.001). Postoperative complications noted were not different between the two groups. Faster visual recovery and better long-term outcomes were observed in keratoconus patients who had FLEK compared with those who had the mechanical PKP procedure with 6 months of postoperative follow-up.

  4. Penetrating keratoplasty using femtosecond laser-enabled keratoplasty with zig-zag incisions versus a mechanical trephine in patients with keratoconus

    PubMed Central

    Gaster, Ronald N; Dumitrascu, Oanna; Rabinowitz, Yaron S

    2013-01-01

    Background/aims This paper will compare the visual outcomes of two different penetrating keratoplasty (PKP) techniques in patients with keratoconus. It is a retrospective comparative surgical case series of 116 keratoconus patients (137 eyes) who had PKP at the Cornea Eye Institute, Beverly Hills, California, USA. Methods 56 keratoconus patients (66 eyes) underwent femtosecond laser-enabled keratoplasty (FLEK) with a zig-zag incision configuration. Their visual parameters were compared with those of 60 patients (71 eyes) who had traditional blade mechanical trephination PKP. The range of follow-up was between 3 and 6 months. The main outcome measures included uncorrected visual acuity and best spectacle-corrected visual acuity (BSCVA), manifest refractive spherical equivalent and topographically determined astigmatism. Results BSCVA was significantly better as early as 3 months postoperatively (p=0.001) in the FLEK group. Visual recovery to 20/40 after 3 months was significantly better in the FLEK group (p<0.001). Topographic astigmatism was lower in the FLEK group, but the difference between the two groups reached significance only at 3 months of follow-up (p=0.001). Postoperative complications noted were not different between the two groups. Conclusions Faster visual recovery and better long-term outcomes were observed in keratoconus patients who had FLEK compared with those who had the mechanical PKP procedure with 6 months of postoperative follow-up. PMID:22790433

  5. Endothelial Cell Density to Predict Endothelial Graft Failure After Penetrating Keratoplasty

    PubMed Central

    Lass, Jonathan H.; Sugar, Alan; Benetz, Beth Ann; Beck, Roy W.; Dontchev, Mariya; Gal, Robin L.; Kollman, Craig; Gross, Robert; Heck, Ellen; Holland, Edward J.; Mannis, Mark J.; Raber, Irving; Stark, Walter; Stulting, R. Doyle

    2010-01-01

    Objective To determine whether preoperative and/or postoperative central endothelial cell density (ECD) and its rate of decline postoperatively are predictive of graft failure caused by endothelial decompensation following penetrating keratoplasty to treat a moderate-risk condition, principally, Fuchs dystrophy or pseudophakic corneal edema. Methods In a subset of Cornea Donor Study participants, a central reading center determined preoperative and postoperative ECD from available specular images for 17 grafts that failed because of endothelial decompensation and 483 grafts that did not fail. Results Preoperative ECD was not predictive of graft failure caused by endothelial decompensation (P = .91). However, the 6-month ECD was predictive of subsequent failure (P < .001). Among those that had not failed within the first 6 months, the 5-year cumulative incidence (±95% confidence interval) of failure was 13% (±12%) for the 33 participants with a 6-month ECD of less than 1700 cells/mm2 vs 2%(±3%) for the 137 participants with a 6-monthECDof 2500 cells/mm2 or higher. After 5 years’ follow-up, 40 of 277 participants (14%) with a clear graft had an ECD below 500 cells/mm2. Conclusions Preoperative ECD is unrelated to graft failure from endothelial decompensation, whereas there is a strong correlation of ECD at 6 months with graft failure from endothelial decompensation. A graft can remain clear after 5 years even when the ECD is below 500 cells/mm2. PMID:20065219

  6. Weighing of risk factors for penetrating keratoplasty graft failure: application of Risk Score System

    PubMed Central

    Tourkmani, Abdo Karim; Sánchez-Huerta, Valeria; De Wit, Guillermo; Martínez, Jaime D.; Mingo, David; Mahillo-Fernández, Ignacio; Jiménez-Alfaro, Ignacio

    2017-01-01

    AIM To analyze the relationship between the score obtained in the Risk Score System (RSS) proposed by Hicks et al with penetrating keratoplasty (PKP) graft failure at 1y postoperatively and among each factor in the RSS with the risk of PKP graft failure using univariate and multivariate analysis. METHODS The retrospective cohort study had 152 PKPs from 152 patients. Eighteen cases were excluded from our study due to primary failure (10 cases), incomplete medical notes (5 cases) and follow-up less than 1y (3 cases). We included 134 PKPs from 134 patients stratified by preoperative risk score. Spearman coefficient was calculated for the relationship between the score obtained and risk of failure at 1y. Univariate and multivariate analysis were calculated for the impact of every single risk factor included in the RSS over graft failure at 1y. RESULTS Spearman coefficient showed statistically significant correlation between the score in the RSS and graft failure (P<0.05). Multivariate logistic regression analysis showed no statistically significant relationship (P>0.05) between diagnosis and lens status with graft failure. The relationship between the other risk factors studied and graft failure was significant (P<0.05), although the results for previous grafts and graft failure was unreliable. None of our patients had previous blood transfusion, thus, it had no impact. CONCLUSION After the application of multivariate analysis techniques, some risk factors do not show the expected impact over graft failure at 1y. PMID:28393027

  7. Pre-banking microbial contamination of donor conjunctiva and storage medium for penetrating keratoplasty.

    PubMed

    Inomata, Takenori; Ono, Koichi; Matsuba, Tsuyoshi; Shiang, Tina; Di Zazzo, Antonio; Nakatani, Satoru; Yamaguchi, Masahiro; Ebihara, Nobuyuki; Murakami, Akira

    2017-06-08

    The aims of this study were to investigate the incidence of positive donor tissue cultures before transfer to preservation medium (Optisol™-GS) for penetrating keratoplasty, to verify the efficacy of antibiotics contained in Optisol™-GS by examining the drug susceptibility and to assess the relationship between the results of our microbial assessments as well as donor factors and the incidence of contamination. We conducted a retrospective, cross-sectional study using Juntendo Eye Bank records for all corneal transplantations. Two hundred donor conjunctiva harvestings and storage medium (EP-II(®)) cultures were performed between July 2008 and June 2011. We analyzed the associations between donor factors (age, gender, history of cataract surgery, death-to-preservation interval, cause of death) and contamination rates using multivariate analysis by the generalized estimating equation model. We obtained positive bacterial cultures from 154 of the 200 eyes (77.0%). The isolated bacteria were indigenous, such as coagulase-negative Staphylococci, Corynebacterium sp., and methicillin-resistant Staphylococcus aureus (MRSA). There was significant resistance to levofloxacin (18 eyes, 9.0%) and gentamicin (12 eyes, 6.0%), and no vancomycin-resistant bacteria were detected. The donor factors did not correlate with the prevalence of bacterial contamination in our criteria. Pre-banking microbial assessment allows for microbial detection, bacterial susceptibility and resistance testing. This is useful for developing preservation mediums containing effective spectrum antibiotic agents for high quality control of corneal banking.

  8. Corticosteroid-induced intraocular pressure elevation in keratoconus is common following uncomplicated penetrating keratoplasty.

    PubMed

    Fan, J C; Chow, K; Patel, D V; McGhee, C N J

    2009-11-01

    To determine the incidence of postkeratoplasty intraocular pressure (IOP) elevation in the eyes of subjects with keratoconus and establish the relationship between IOP and corticosteroid administrations in this population. Following strict inclusion/exclusion criteria, a retrospective analysis was performed on a consecutive series of penetrating keratoplasties performed for keratoconus observing a standardised surgical and postoperative regimen in Auckland, New Zealand. Patient demographics, ocular, medical, and family history, and pre- and postoperative data were recorded until 12 months postkeratoplasty. In all, 57 eyes of 48 patients were included-31% New Zealand Europeans, 42% Pacific people, 15% Maori, and 12% other. Eighteen eyes (32%) of 17 patients (35%) exhibited elevated IOP and 12 (21%) eyes exhibited moderate-to-severe elevation of IOP. IOP elevation occurred 3-6 months postkeratoplasty in 78% of eyes. Elevated IOP was significantly less common in Maori and Pacific peoples (P=0.02). All eyes except one required reduction/cessation of corticosteroids to normalise IOP. The incidence of presumed steroid-related postkeratoplasty IOP elevation, in 35% of subjects with keratoconus, is markedly higher in this New Zealand study than previously reported in the US and UK studies. Further clinical and genetic analysis of associations between keratoconus and steroid-induced IOP elevation and glaucoma might improve our current understanding of this condition.

  9. Customized photorefractive keratectomy to correct high ametropia after penetrating keratoplasty: A pilot study

    PubMed Central

    De Rosa, Giuseppe; Boccia, Rosa; Santamaria, Carmine; Fabbozzi, Lorenzo; De Rosa, Luigi; Lanza, Michele

    2014-01-01

    Purpose To evaluate preliminarily the safety and efficacy of customized photorefractive keratectomy (PRK) to correct ametropia and irregular astigmatism after penetrating keratoplasty (PK). Methods This pilot study included five eyes of five patients with a mean spherical equivalent of −5.1 ± 1.46 D (range from −2.75 to −6.50 D). In all cases, ametropia and irregular astigmatism was corrected with topography-guided customized PRK. Ocular examinations with topographic analysis were performed preoperatively as well as at 1, 3 and 6 months after surgery. Results All eyes gained postoperatively at least three Snellen lines of uncorrected visual acuity. Mean refractive spherical equivalent was 0.62 ± 0.63 D (range from −0.25 to −1.75 D) at 6 months postoperatively. Conclusion Our pilot study suggests that customized PRK can be a safe and effective method for treating ametropia and irregular astigmatisms after PK. Future studies with larger samples and longer follow-ups should be performed to confirm these results. PMID:25151176

  10. Randomized Comparison Between Rebamipide Ophthalmic Suspension and Diquafosol Ophthalmic Solution for Dry Eye After Penetrating Keratoplasty.

    PubMed

    Kobashi, Hidenaga; Kamiya, Kazutaka; Shimizu, Kimiya

    To compare the ocular surfaces of patients treated with rebamipide (REB) ophthalmic suspension or diquafosol (DQS) ophthalmic solution for dry eye syndrome after penetrating keratoplasty (PK). A total of 40 eyes of 40 patients who had dry eyes after undergoing PK were enrolled and randomly divided into an REB group and a DQS group. Both REB and DQS groups used each eye drop four times. The tear breakup time (TBUT), corneal fluorescein staining scores, and dry eye-related quality-of-life score (DEQS) were evaluated before treatment, 2 weeks after start of treatment and 4 weeks after start of treatment. We found a significant improvement in TBUT (P < 0.001, Dunnett's test) and fluorescein scores (P < 0.001) 4 weeks after treatment in the REB group. Similar results were obtained in the DQS group (P < 0.001 and P = 0.01, respectively). No significant improvements in DEQS were found 4 weeks after treatment in each group (P = 0.15 and P = 0.63, analysis of variance, respectively). No significant differences were seen in these variables and in the changes between the groups after treatment. REB and DQS may be effective for the management of dry eye syndrome after PK in terms of ocular surface findings. In our study, effects of REB appear to be equivalent to those of DQS in the patients.

  11. Factor XIII subunits in human tears; their highly elevated levels following penetrating keratoplasty.

    PubMed

    Orosz, Zsuzsanna Z; Katona, Éva; Facskó, Andrea; Módis, László; Muszbek, László; Berta, András

    2011-01-30

    As blood coagulation factor XIII (FXIII) is of high importance in wound healing, we determined the concentrations of FXIII A and B subunits (FXIII-A and FXIII-B) and their complex (FXIII-A(2)B(2)) in normal tears and in tears from patients undergoing penetrating keratoplasty (PKP). FXIII complex and subunit concentrations were measured by highly sensitive chemiluminescent ELISAs in tears from 60 healthy volunteers and from 31 patients undergoing corneal transplantation. In non-stimulated tears from healthy volunteers, low but consistent amounts of FXIII-A and FXIII-B (medians: 2.13 μg/L and 7.22 μg/L, respectively) were measured, mostly in non-complexed form. Following stimulation of tear secretion FXIII levels moderately decreased, but if normalized to protein concentration they did not change. One day after PKP FXIII levels became highly elevated, then gradually decreased, but even on day 7 significantly exceeded pre-surgery values. The elevation of tear FXIII levels was significantly higher in PKP patients who later developed neovascularization of donor cornea. FXIII subunits are low concentration components of normal tear. The striking elevation of FXIII subunit and FXIII-A(2)B(2) concentrations after PKP suggests the involvement of FXIII in corneal wound healing. Perioperatively measured high FXIII levels in tears seem to represent a risk of neovascularization. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Endothelial cell density to predict endothelial graft failure after penetrating keratoplasty.

    PubMed

    Lass, Jonathan H; Sugar, Alan; Benetz, Beth Ann; Beck, Roy W; Dontchev, Mariya; Gal, Robin L; Kollman, Craig; Gross, Robert; Heck, Ellen; Holland, Edward J; Mannis, Mark J; Raber, Irving; Stark, Walter; Stulting, R Doyle

    2010-01-01

    To determine whether preoperative and/or postoperative central endothelial cell density (ECD) and its rate of decline postoperatively are predictive of graft failure caused by endothelial decompensation following penetrating keratoplasty to treat a moderate-risk condition, principally, Fuchs dystrophy or pseudophakic corneal edema. In a subset of Cornea Donor Study participants, a central reading center determined preoperative and postoperative ECD from available specular images for 17 grafts that failed because of endothelial decompensation and 483 grafts that did not fail. Preoperative ECD was not predictive of graft failure caused by endothelial decompensation (P = .91). However, the 6-month ECD was predictive of subsequent failure (P < .001). Among those that had not failed within the first 6 months, the 5-year cumulative incidence (+/-95% confidence interval) of failure was 13% (+/-12%) for the 33 participants with a 6-month ECD of less than 1700 cells/mm(2) vs 2% (+/-3%) for the 137 participants with a 6-month ECD of 2500 cells/mm(2) or higher. After 5 years' follow-up, 40 of 277 participants (14%) with a clear graft had an ECD below 500 cells/mm(2). Preoperative ECD is unrelated to graft failure from endothelial decompensation, whereas there is a strong correlation of ECD at 6 months with graft failure from endothelial decompensation. A graft can remain clear after 5 years even when the ECD is below 500 cells/mm(2).

  13. Ahmed glaucoma valve in post-penetrating-keratoplasty glaucoma: A critically evaluated prospective clinical study

    PubMed Central

    Panda, Anita; Prakash, Vadivelu Jaya; Dada, Tanuj; Gupta, Anoop Kishore; Khokhar, Sudarshan; Vanathi, Murugesan

    2011-01-01

    Aim: The aim was to evaluate the outcome of Ahmed glaucoma valve (AGV) in post-penetrating-keratoplasty glaucoma (PKPG). Materials and Methods: In this prospective study, 20 eyes of 20 adult patients with post-PKPG with intraocular pressure (IOP) >21 mmHg, on two or more antiglaucoma medications, underwent AG (model FP7) implantation and were followed up for a minimum of 6 months. Absolute success was defined as 5

  14. Customized photorefractive keratectomy to correct high ametropia after penetrating keratoplasty: A pilot study.

    PubMed

    De Rosa, Giuseppe; Boccia, Rosa; Santamaria, Carmine; Fabbozzi, Lorenzo; De Rosa, Luigi; Lanza, Michele

    2015-01-01

    To evaluate preliminarily the safety and efficacy of customized photorefractive keratectomy (PRK) to correct ametropia and irregular astigmatism after penetrating keratoplasty (PK). This pilot study included five eyes of five patients with a mean spherical equivalent of -5.1±1.46D (range from -2.75 to -6.50D). In all cases, ametropia and irregular astigmatism was corrected with topography-guided customized PRK. Ocular examinations with topographic analysis were performed preoperatively as well as at 1, 3 and 6 months after surgery. All eyes gained postoperatively at least three Snellen lines of uncorrected visual acuity. Mean refractive spherical equivalent was 0.62±0.63D (range from -0.25 to -1.75D) at 6 months postoperatively. Our pilot study suggests that customized PRK can be a safe and effective method for treating ametropia and irregular astigmatisms after PK. Future studies with larger samples and longer follow-ups should be performed to confirm these results. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  15. Prognostic factors for corneal graft recovery after severe corneal graft rejection following penetrating keratoplasty

    PubMed Central

    2013-01-01

    Background To investigate the outcome and prognostic factors for corneal graft recovery after severe corneal graft rejection following penetrating keratoplasty (PKP) treated with topical and systemic steroids. Methods Fifty-eight eyes in 58 patients with severe corneal graft rejection following PKP were treated with topical and systemic steroids. Factors affecting the reversibility and maintenance of graft transparency were analyzed. Results Graft transparency was restored in 37 of 58 eyes (63.8%). Clarity of the graft was maintained in 25 of 37 eyes after transparency was restored, while corneal decompensation developed at a mean of 6.0 ± 4.3 months in the remainder. The interval between rejection and treatment with systemic steroids was shorter in cases that recovered graft transparency (OR, 0.88, 95% CI. 0.80–0.97, P = 0.0093). Corneal decompensation after the recovery of corneal transparency tend to occur in cases of regraft (OR, 0.09, 95% CI. 0.01–0.54, P = 0.0091). Conclusions Severe corneal graft rejection after PKP was reversible in approximately two-thirds of the cases, with graft transparency being maintained in two-thirds of them when treated with both topical and systemic steroids. Early treatment confers a benefit in terms of the recovery of graft transparency. PMID:23432898

  16. Epidemiology and molecular analysis of herpes simplex keratitis requiring primary penetrating keratoplasty

    PubMed Central

    Branco, B C; Gaudio, P A; Margolis, T P

    2004-01-01

    Aims: To determine whether herpes simplex keratitis (HSK) has declined as an indication for penetrating keratoplasty (PKP) at the University of California San Francisco (UCSF) over the past 30 years. Methods: Records of the Hogan Eye Pathology Laboratory were reviewed to determine the incidence of PKP performed for HSK from 1972 through 2001. Archived corneal tissue with the diagnosis of HSK was evaluated for herpes simplex virus (HSV) DNA by polymerase chain reaction (PCR) based assays. Results: The number of corneal buttons submitted with the clinical diagnosis of HSK decreased from 1972 to 2001, while the overall number of PKPs performed did not. The percentage of corneal buttons with a clinical diagnosis of HSK that contained detectable HSV DNA did not change over the course of the study period. Conclusion: HSK declined as an indication for PKP from 1972 to 2001 at UCSF. It is unlikely that this decline was the result of improved diagnostic accuracy since detection of HSV DNA in corneal buttons with a clinical diagnosis of HSK was similar at the beginning and end of the study period. PMID:15377552

  17. Orientation teeth in nonmechanical femtosecond laser corneal trephination for penetrating keratoplasty.

    PubMed

    Mastropasqua, Leonardo; Nubile, Mario; Lanzini, Manuela; Calienno, Roberta; Trubiani, Oriana

    2008-07-01

    To evaluate femtosecond laser-assisted corneal full-thickness trephination with orientation teeth and notches for penetrating keratoplasty (PKP). Interventional case series. Four eyes of four patients aged 34 to 55 years underwent PKP using a femtosecond laser system enabling corneal trephination with orientation teeth and notches. Patients were affected by advanced keratoconus (n = 2) or postinfectious corneal scar (n = 2). Scanning electron microscopy (SEM) was performed to evaluate the cut quality of donor and recipient cornea. All procedures were completed without any complications. In all cases, the donor and the recipient cornea were cut with the same size of 8.0-mm diameter. A complete perforating cut was achieved in all eyes, and a correct intraoperative matching of teeth and notches was obtained. SEM of donor and recipient specimens showed a full-thickness cut with smooth and regular shape of orientation teeth and notches. Orientation teeth and notches shaped PKP using the femtosecond laser technology is feasible and may offer further promising approaches toward customized trephination techniques.

  18. Minimal trephination penetrating keratoplasty for severe fungal keratitis complicated with hypopyon.

    PubMed

    Liu, Yang; Jia, Hui; Shi, Xiaoru; Wang, Jiao; Ning, Yan; He, Bing; Wang, Chunmei; Zheng, Xiaodong

    2013-12-01

    To report outcomes after minimal trephination penetrating keratoplasty (PKP) in the treatment of severe fungal keratitis complicated with hypopyon. Retrospective case series. Series of 19 eyes in 19 patients with severe fungal keratitis complicated with hypopyon that received minimal trephination PKP. The host trephination was made equal to or smaller than the margin of the corneal lesion. Fluconazole (0.2%) was used to irrigate the trephined edge and anterior chamber during surgery, followed by irrigation of the anterior chamber with a 0.02% fluconazole solution after graft transplantation. Postoperative complications, graft rejection, transparency rate, and visual acuity were recorded. Patients were followed postoperatively for 18 to 34 months (mean 28.6 months). At 18 months after PKP, 18 grafts (94.7%) remained clear and 14 eyes (73.7%) had improved visual acuity. Three eyes (15.8%) with secondary glaucoma complications after PKP were treated with subsequent trabeculectomy. Recurrent infection was found in only 1 eye (5.26%) after transplantation and was successfully managed. Immune graft rejections were not observed in any patient during the follow-up period. The minimal trephination technique in combination with antifungal therapy was effective in the treatment of severe fungal keratitis with large corneal lesions and hypopyon. Copyright © 2013 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  19. Stimulated penetrating keratoplasty using real-time virtual intraoperative surgical optical coherence tomography

    PubMed Central

    Lee, Changho; Kim, Kyungun; Han, Seunghoon; Kim, Sehui; Lee, Jun Hoon; Kim, Hong kyun; Kim, Chulhong; Jung, Woonggyu; Kim, Jeehyun

    2014-01-01

    Abstract. An intraoperative surgical microscope is an essential tool in a neuro- or ophthalmological surgical environment. Yet, it has an inherent limitation to classify subsurface information because it only provides the surface images. To compensate for and assist in this problem, combining the surgical microscope with optical coherence tomography (OCT) has been adapted. We developed a real-time virtual intraoperative surgical OCT (VISOCT) system by adapting a spectral-domain OCT scanner with a commercial surgical microscope. Thanks to our custom-made beam splitting and image display subsystems, the OCT images and microscopic images are simultaneously visualized through an ocular lens or the eyepiece of the microscope. This improvement helps surgeons to focus on the operation without distraction to view OCT images on another separate display. Moreover, displaying the OCT live images on the eyepiece helps surgeon’s depth perception during the surgeries. Finally, we successfully processed stimulated penetrating keratoplasty in live rabbits. We believe that these technical achievements are crucial to enhance the usability of the VISOCT system in a real surgical operating condition. PMID:24604471

  20. Long-term results of deep anterior lamellar versus penetrating keratoplasty.

    PubMed

    Borderie, Vincent M; Sandali, Otman; Bullet, Julien; Gaujoux, Thomas; Touzeau, Olivier; Laroche, Laurent

    2012-02-01

    To compare deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in eyes with corneal diseases not involving the corneal endothelium (keratoconus, scars after infectious keratitis, stromal dystrophies, and trauma). Retrospective, comparative case series. One hundred forty-two consecutive DALK (DALK group; big-bubble technique or manual lamellar dissection using a slitlamp) and 142 matched PK (PK group). Three models were used to describe the postoperative outcomes of the endothelial cell density. A joint regression model was used to predict long-term graft survival. Visual acuity, ultrasound pachymetry, specular microscopy, and optical coherence tomography (OCT) findings were recorded. Postoperative endothelial cell loss and long-term predicted graft survival. The average 5-year postoperative endothelial cell loss was -22.3% in the DALK group and -50.1% in the PK group (P<0.0001). The early- and late-phase annual rates of endothelial cell loss were -8.3% and -3.9% per year, respectively, in the DALK group and -15.2% and -7.8% per year in the PK group (P<0.001; biphasic linear model). The median predicted graft survival was 49.0 years in the DALK group and 17.3 years in the PK group (P<0.0001). The average visual acuity was lower in the manual dissection subgroup compared with the PK group (average difference, 1.0 to 1.8 line) and with the big-bubble subgroup (average difference, 2.2 to 2.5 lines). The average central corneal thickness at 12 months was 536 μm in the PK group, 523 μm in the big-bubble subgroup, and 562 μm in the manual dissection subgroup (P<0.001). The average thickness of the residual recipient stroma measured by OCT was 87±26 μm in the manual dissection subgroup. No correlation was found between this figure and logarithm of the minimal angle of resolution at any postoperative time point (P>0.05). Long-term, model-predicted graft survival and endothelial densities are higher after DALK than after PK. The big

  1. [Rhegmatogenous retinal detachment in a patient with previous penetrating keratoplasty (clinical case)].

    PubMed

    Burcea, M; Muşat, O; Gheorghe, Andreea; Mahdi, Labib; Colta, Diana; Cernat, Corina; Mansour, Agajani

    2014-01-01

    We present the case of a 54 year old patient diagnosed with rhegmatogenous retinal detachment and perforating keratoplasty. Surgery is recommended and we performed posterior vitrectomy, endolaser, and internal heavy oil tamponade. The post-operative course was favorable.

  2. Evaluation of the Central Corneal Thickness with Anterior Segment Optical Coherence Tomogram after Penetrating Keratoplasty

    PubMed Central

    Dhasmana, Renu; Bahadur, Harsh; Nagpal, Ramesh Chander

    2016-01-01

    Introduction Graft central thickness evaluates the graft quality which affects the outcome of Penetrating Keratoplasty (PK). It varies at different point of time after PK. Anterior Segment Optical Coherence Tomography (ASOCT) can measure graft’s central thickness with quite high precision. Aim The purpose of the study was to monitor the Central Corneal thickness (CCT) with ASOCT after PK and to evaluate its relationship with the pre-operative diagnosis. Materials and Methods This is an observational retrospective study where records of optical PK done in December 2012 and June 2015 were reviewed. Graft central thickness were analysed by ASOCT for all the patients post-operatively at first post-operative day, 3 and 6 months post PK by pachymetry scan and the images captured were analysed for CCT with inbuilt calipers. Results Fifty one eyes of 50 patients with age range of 17-80years (mean 51.64years ±SD 18.45 years) with clear grafts were reviewed in the present study. All subjects recruited were analysed for the indications of PK. Adherent leucoma 20(39.21%) was most common indication for PK. Mean CCT were 647.31±90.40, 605.31±75.08,564.66±66.26 and 537.37±64.09 respectively on first post-operative day, 1, 3 and 6 months. Graft CCT significantly decreased between first post-operative day and 1 month and it showed further decrease at 3 to 6 months post PK. The CCT at 6 month post-surgery showed a strongly positive correlation with the Intraocular Pressure (IOP) (r=0.66) and weakly positive correlation with Best Corrected Visual Acuity (BCVA) (r=0.28). Conclusion Graft central thickness is considered to be quantitative method for evaluating corneal oedema post PK. CCT decreases in post-operative period irrespective of indications of PK. PMID:27891366

  3. Safety of prophylactic intracameral moxifloxacin ophthalmic solution after cataract surgery in patients with penetrating keratoplasty

    PubMed Central

    Arslan, Osman Sevki; Arici, Ceyhun; Unal, Mustafa; Cicik, Erdogan; Mangan, Mehmet Serhat; Atalay, Eray

    2014-01-01

    AIM To determine the safety of prophylactic intracameral moxifloxacin after cataract surgery in patients with penetrating keratoplasty (PKP). METHODS In this retrospective study of consecutive patients who had phacoemulsification cataract surgery after PKP, were treated with intracameral moxifloxacin 0.5% ophthalmic solution (0.5 mg/0.1 mL). The main outcome measures were anterior chamber reaction, best corrected visual acuity (BCVA), corneal endothelial cell count (ECC), and central corneal thickness (CCT). RESULTS Fifty-five patients were recruited (26 males, 29 females). The mean age was 54.36±4.97y (range 45-64y). All eyes had improved postoperative BCVA. The mean BCVA was 0.25 preoperatively and 0.57 postoperatively, which was statistically significant (P<0.001). One eye had 3+, 7 eyes had 2+, 12 eyes had 1+ and 8 eyes had trace amount of aqueous cells on the first day after surgery. All eyes had no anterior chamber cells at subsequent follow up examinations. Effective phacoemulsification time was 4.33±1.01s. The mean ECC was 2340.20 cells/mm2 preoperatively and 1948.75 cells/mm2 1mo postoperatively (P<0.001). The increase of 21.09 µm in postoperative pachymetry 1mo after surgery was statistically significant (P<0.001). CONCLUSION No untoward effects were observed after intracameral injection of moxifloxacin (0.5 mg/0.1 mL) in terms of anterior chamber reaction, CCT, ECC, and visual rehabilitation at the conclusion of cataract surgery in patients with PKP. PMID:25349795

  4. Long-term outcomes of penetrating keratoplasty in chronic and delayed mustard gas keratitis.

    PubMed

    Javadi, Mohammad Ali; Yazdani, Shahin; Kanavi, Mozhgan Rezaei; Mohammadpour, Mehrdad; Baradaran-Rafiee, Alireza; Jafarinasab, Mohammad Reza; Einollahi, Bahram; Karimian, Farid; Zare, Mohammad; Naderi, Mostafa; Rabei, Hossein Mohammad

    2007-10-01

    To report the long-term outcomes of penetrating keratoplasty (PKP) in war victims with chronic and delayed mustard gas keratitis. This noncomparative interventional case series includes patients with advanced chronic or delayed mustard gas keratitis who had undergone PKP from 1989 to 2006. Best-corrected visual acuity (BCVA), graft clarity, episodes of graft rejection, duration of steroid use, and complications were evaluated. Histopathologic features of excised corneal buttons were also evaluated. Overall, 22 eyes of 19 patients underwent PKP. Mean age at the time of surgery was 41 +/- 4.6 years (range, 36-54 years), and mean follow-up duration was 40.9 +/- 48 months (range, 4-204 months). The graft remained clear in 17 (77.3%) eyes and failed in 5 (22.7%) eyes. Overall, 13 (59.1%) eyes experienced episodes of endothelial rejection, and 5 (22.7%) eyes had subepithelial immune rejection, 4 of which had simultaneous endothelial rejection. Fifteen (68.2%) eyes received topical steroids for >6 months. Fourteen (63.6%) eyes developed cataracts, leading to cataract extraction in 7 eyes. One eye developed steroid-induced glaucoma after multiple episodes of endothelial graft rejections. Mean preoperative BCVA was 1.92 +/- 0.63 logMAR, which improved to 1.04 +/- 0.65 logMAR (20/200) overall and 0.8 +/- 0.3 logMAR (20/120) in eyes with clear grafts (P < 0.001). Main histopathologic features of excised corneal buttons included corneal thinning and ulceration, loss of keratocytes, acute and chronic inflammation, stromal vascularization, and degenerative sequelae of long-standing inflammation. PKP in chronic or delayed-onset mustard gas keratitis should be considered as a high-risk graft; however, with appropriate management, graft clarity and visual outcomes may be favorable.

  5. [Long-term results of lasik refractive error correction after penetrating keratoplasty in patients with keratoconus].

    PubMed

    Donoso, R; Díaz, C; Villavicencio, P

    2015-07-01

    To evaluate the long term results of Lasik for residual refractive errors (RE) after penetrating keratoplasty (PKP) for keratoconus (KC). Retrospective cohort. Records of 14 consecutive patients (19 eyes) who had Lasik after PKP for KC were retrospectively reviewed. In all eyes with refractive stability and suture removed before Lasik, far distance Visual Acuity with (AVCC) and without correction (AVSC), spherical equivalent (EE), refractive (Ast) and keratometric (dK) astigmatism were analyzed pre- and post-operatively before and after one year of follow up. Data were analyzed using Shapiro-Wilk normality test, Student t test and Mann-Whitney test. A P-value of <0,05 was considered statistically significant. The mean follow-up time was 3.16 months for the follow-up before one year postoperative and 5.8 years for the follow-up after one year postoperative. The best spectacle corrected visual acuity of 0,11 LogMAR (DE 0,07) before Lasik remained stable throughout the study. The SE decreased from -2.6 (DE 3.53) to -0,36 D (DE 1.33) (P<.05) for the follow-up before one year postoperative and -1.28 D (DE 1.63) (P=.07) for the follow-up after one year postop. The refractive cylinder was reduced from -3.43 (DE 1.35) preoperative to -1.37 D (DE 1.24) (P<.05) and -3.21 D (DE 2.29) (P=.36) in the long term after one year of follow-up. Lasik refractive results regress one year after the operation; therefore it is not an effective long-term surgical refractive procedure for residual refractive errors after PKP for KC. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  6. Laser welding in penetrating keratoplasty and cataract surgery in pediatric patients: early results.

    PubMed

    Buzzonetti, Luca; Capozzi, Paolo; Petrocelli, Gianni; Valente, Paola; Petroni, Sergio; Menabuoni, Luca; Rossi, Francesca; Pini, Roberto

    2013-12-01

    To evaluate the efficacy of diode laser welding to close corneal wounds in penetrating keratoplasty (PKP) and cataract surgery in pediatric patients. Ophthalmology Department, Bambino Gesù Children's Hospital, Rome, Italy. Prospective observational study. Patients had surgery for congenital cataract (Group 1) or femtosecond laser-assisted PKP (Group 2). The surgery was followed by corneal wound closure using diode laser welding of the stroma. In Group 1, no standard suturing was used. In Group 2, the donor button was sutured onto the recipient using 8 single nylon sutures or a 10-0 nylon running suture (12 passages). Laser welding was then used as an adjunct to the traditional suturing procedure. Group 1 comprised 7 eyes (7 patients; mean age 8.1 years ± 5.3 [SD], range 1 to 15 years) and Group 2, 5 eyes (5 patients; mean age 10.6 ± 3.3 years, range 6 to 15 years). The adhesion of the laser-welded tissues was perfect; there were no collateral effects, and restoration of the treated tissues was optimum. Seidel testing showed no wound leakage during the follow-up. Postoperative astigmatism did not change significantly from the first day after cataract surgery and shifted moderately 3 months after PKP. Laser welding of corneal tissue appeared to be safe and effective in children for whom a sutureless surgical procedure is important to reduce the use of anesthesia for suture management, prevent endophthalmitis, and improve the antiamblyopic effect. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Corneal graft rejection 10 years after penetrating keratoplasty in the cornea donor study.

    PubMed

    Dunn, Steven P; Gal, Robin L; Kollman, Craig; Raghinaru, Dan; Dontchev, Mariya; Blanton, Christopher L; Holland, Edward J; Lass, Jonathan H; Kenyon, Kenneth R; Mannis, Mark J; Mian, Shahzad I; Rapuano, Christopher J; Stark, Walter J; Beck, Roy W

    2014-10-01

    The aim of this study was to assess the effect of donor and recipient factors on corneal allograft rejection and evaluate whether a rejection event was associated with graft failure. One thousand ninety subjects undergoing penetrating keratoplasty for a moderate risk condition (principally Fuchs dystrophy or pseudophakic corneal edema) were followed for up to 12 years. Associations of baseline recipient and donor factors with the occurrence of a rejection event were assessed in univariate and multivariate proportional hazards models. Among 651 eyes with a surviving graft at 5 years, the 10-year graft failure (±99% confidence interval) rates were 12% ± 4% among eyes with no rejection events in the first 5 years, 17% ± 12% in eyes with at least 1 probable, but no definite rejection event, and 22% ± 20% in eyes with at least 1 definite rejection event. The only baseline factor significantly associated with a higher risk of definite graft rejection was a preoperative history of glaucoma, particularly when previous glaucoma surgery had been performed and glaucoma medications were being used at the time of transplant (10-year incidence 35% ± 23% compared with 14% ± 4% in eyes with no history of glaucoma/intraocular pressure treatment, P = 0.008). Patients who experienced a definite rejection event frequently developed graft failure raising important questions as to how we might change acute and long-term corneal graft management. Multivariate analysis indicated that previous use of glaucoma medications and glaucoma filtering surgery was a significant risk factor related to a definite rejection event.

  8. Comparison of intraocular pressure measurement using 4 different instruments following penetrating keratoplasty.

    PubMed

    Chou, Chi-Ying; Jordan, Charlotte A; McGhee, Charles N J; Patel, Dipika V

    2012-03-01

    To compare intraocular pressure (IOP) measurements after penetrating keratoplasty (PK) using Goldmann applanation tonometry (GAT; Haag-Streit USA), TonoPen XL (Reichert Inc), Pascal Dynamic Contour tonometer (PDCT; Swiss Microtechnology AG), and Ocular Response Analyzer (ORA; Reichert Inc) and to analyze effects and correlation of corneal thickness and curvature on these measurements. Prospective, cross-sectional study. Departments of Ophthalmology, University of Auckland and Auckland District Health Board, New Zealand. Thirty-one eyes of 31 participants with previous PK. IOP measured using GAT, TonoPen, PDCT, and ORA. Central corneal thickness (CCT) and corneal astigmatism were assessed by Pentacam rotating Scheimpflug tomography. Degree of agreement in IOP measures and correlation with CCT and corneal astigmatism. Mean age was 44.5 ± 21.0 years and mean time since PK was 27.7 ± 28.2 months (range 3.0-122.4 months). Mean CCT was 585 ± 149 μm and mean corneal astigmatism 5.5 ± 3.8 diopters. There was no significant difference in IOP measured by GAT and TonoPen; however, both PDCT (2.12 mm Hg, P < .01) and ORA (6.29 mm Hg, P < .01) measured significantly higher IOPs compared to GAT. ORA showed the least agreement with GAT. Significant correlation was identified between each pair of measurement techniques. No instruments correlated significantly with CCT. Only PDCT showed no significant correlation with corneal astigmatism. However, no IOP measures correlated with corneal astigmatism if sutures in situ or less than 1 year post-PK. TonoPen or PDCT are the most suitable alternatives for measuring IOP in PK eyes where GAT readings are difficult to obtain. PDCT also offers the advantage of being independent of both CCT and corneal astigmatism. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Five-year Outcomes of Eyes With Glaucoma Drainage Device and Penetrating Keratoplasty

    PubMed Central

    Knape, Robert M.; Szymarek, Tiffany N.; Tuli, Sonal S.; Driebe, William T.; Sherwood, Mark B.; Smith, Mary Fran

    2013-01-01

    Purpose To investigate intraocular pressure (IOP) control and corneal graft survival rates in eyes with glaucoma drainage device (GDD) implantation and penetrating keratoplasty (PK) and 5 years of follow-up data. Design Retrospective review. Methods We performed a review of records of all patients who underwent both GDD placement and PK at our institution between January 1, 1988 and December 31, 2003. Twenty-eight eyes of 27 patients were studied. Glaucoma outcome was assessed by postoperative IOP, number of glaucoma medications, and need for further glaucoma surgery. Corneal grafts were assessed for clarity. Results All eyes had GDD placement in the anterior chamber. The mean pre-GDD IOP was 28.8 ± 10.3 mm Hg on a mean of 2.6 ± 0.8 glaucoma medications. At 5-year follow-up, the mean IOP was 13.0 ± 5.9 mm Hg on a mean of 0.9 ± 1.0 glaucoma medications. GDD implantation successfully controlled glaucoma in 96%, 86%, 79%, 75%, and 71% of eyes at 1, 2, 3, 4, and 5 years, respectively. Grafts remained clear in 96%, 82%, 75%, 57%, and 54% of eyes at 1, 2, 3, 4, and 5 years, respectively. Failure of glaucoma outcome or graft survival was associated with prior intraocular surgeries. Conclusions Our data suggests that GDD placement can provide glaucoma control in a high percentage (71%) of eyes with PK even at 5 years. Furthermore, the success of PK in eyes with GDD remains reasonable (54%) at 5 years. IOP control and graft survival rates are comparable with earlier published studies with shorter follow-up or tube placement in the vitreous cavity. PMID:21602705

  10. Beveled Femtosecond Laser Astigmatic Keratotomy for the Treatment of High Astigmatism Post–Penetrating Keratoplasty

    PubMed Central

    Cleary, Catherine; Tang, Maolong; Ahmed, Habeeb; Fox, Martin; Huang, David

    2013-01-01

    Purpose To use beveled femtosecond laser astigmatic keratotomy (FLAK) incisions to treat high astigmatism after penetrating keratoplasty. Methods Paired FLAK incisions at a bevel angle of 135 degrees, 65% to 75% depth, and arc lengths of 60 to 90 degrees were performed using a femtosecond laser. One case of perpendicular FLAK was presented for comparison. Vector analysis was used to calculate the changes in astigmatism. Fourier domain optical coherence tomography was used to examine incision morphology. Results Wound gaping requiring suturing was observed in the case of perpendicular FLAK. Six consecutive cases of beveled FLAK were analyzed. Fourier domain optical coherence tomography showed that beveled FLAK caused a mean forward shift of Bowman layer anterior to the incisions of 126 ± 38 μm, with no wound gaping. The mean magnitude of preoperative keratometric astigmatism was 9.8 ± 2.9 diopters (D), and postoperatively it was 4.5 ± 3.2 D (P < 0.05). Uncorrected visual acuity improved from 1.24 ± 0.13 logarithm of the minimum angle of resolution preoperatively to 0.76 ± 0.38 postoperatively (P < 0.05). Best spectacle–corrected visual acuity improved from 0.43 ± 0.33 logarithm of the minimum angle of resolution preoperatively to 0.27 ± 0.24 postoperatively (P = 0.22). Visual results were reduced in 2 patients by cataract progression. Between 1 and 3 months after beveled FLAK, the keratometric cylinder was stable (<1 D change) in 5 of 6 patients, and regressed in 1 patient. No complications occurred. Conclusions Beveled FLAK incisions at varied depth are effective in the management of postkeratoplasty astigmatism. Early postoperative changes stabilized within 1 month in most patients. Further studies are needed to assess long-term outcomes. PMID:22968362

  11. Effect of Donor Graft Quality on Clinical Outcomes After Penetrating Keratoplasty for Keratoconus.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad Ali; Ghasemi, Hassan; Javadi, Fatemeh

    2015-01-01

    To evaluate the effect of donor and eye bank characteristics on graft rating and clinical outcomes after penetrating keratoplasty (PK) for keratoconus. This retrospective interventional case series included 252 keratoconic eyes which underwent PK. Donor data included age and sex, cause of death, death-to-preservation time, preservation-to-surgery time, epithelial and stromal status, endothelial cell density (ECD) and morphology, and graft rating. Postoperative outcomes included visual acuity, refractive error, epithelial problems, suture-related complications, graft rejection, and graft transparency. Multivariate regression analysis assessed correlations between donor and eye bank characteristics and graft quality, and postoperative outcomes. Mean recipient and donor age was 29.7 ± 10.0 and 26.2 ± 8.8 years, respectively and mean follow-up period was 66.7 ± 38.5 months. Death-to-preservation time was significantly associated with the presence of graft epithelial sloughing (P = 0.005) and stromal cloudiness (P < 0.001). Donor age significantly influenced ECD (P = 0.02), mean cell area (P = 0.04), and hexagonality (P = 0.01). The presence of epithelial defects on postoperative day 1 correlated significantly with death-to-preservation time (P = 0.004). Graft stromal edema on postoperative day 1 was significantly associated with graft epithelial sloughing (P < 0.001). Postoperative visual and refractive outcomes, complications, and graft survival were not correlated with any donor or eye bank factors. Donor and eye bank variables affected the quality of donor corneas and early postoperative course. However, their long term effect on clinical outcomes, complications, and graft survival were insignificant.

  12. Effect of Penetrating Keratoplasty and Keratoprosthesis Implantation on the Posterior Segment of the Eye

    PubMed Central

    Črnej, Alja; Omoto, Masahiro; Dohlman, Thomas H.; Gonzalez-Andrades, Miguel; Paschalis, Eleftherios I.; Cruzat, Andrea; Vu, T. H. Khanh; Doorenbos, Marianne; Chen, Dong Feng; Dohlman, Claes H.; Dana, Reza

    2016-01-01

    Purpose To compare the effects of post-penetrating keratoplasty (PK) and post-keratoprosthesis (KPro) surgery-related inflammation on the posterior segment of the eye and to assess inhibition of tumor necrosis factor alpha (TNFα) and interleukin-1 beta (IL-1β) on these effects. Methods BALB/C (syngeneic) or C57BL/6 (allogeneic) corneas were transplanted onto BALB/C host beds as part of PK or miniature KPro (m-KPro) implantation. Intraocular pressure (IOP) was measured via an intracameral pressure sensor; tissues were harvested and analyzed 8 weeks after surgery. Expression of TNFα and IL-1β in the retina was analyzed using real-time quantitative (q)PCR. Optic nerve degeneration (axon count, circularity, and area) was assessed quantitatively using ImageJ software. After m-KPro implantation, mice were treated with saline, anti-TNFα, or anti-IL-1β antibody, and axonal loss was assessed after 10 weeks. Results Mean IOP was within normal limits in the operated and fellow eyes in all groups. The mRNA expression of TNFα and IL-1β was highest in m-KPro groups with either syngeneic or an allogeneic carrier. We observed optic nerve degeneration in both allogeneic PK and m-KPro implanted eyes with an allogeneic carrier. However, TNFα blockade significantly reduced axonal loss by 35%. Conclusions Allogeneic PK and m-KPro implants with an allogeneic carrier lead to chronic inflammation in the posterior segment of the eye, resulting in optic nerve degeneration. In addition, blockade of TNFα prevents axonal degeneration in this preclinical model of allogeneic m-KPro (alloKPro) implantation. PMID:27054516

  13. Effect of Donor Graft Quality on Clinical Outcomes After Penetrating Keratoplasty for Keratoconus

    PubMed Central

    Feizi, Sepehr; Javadi, Mohammad Ali; Ghasemi, Hassan; Javadi, Fatemeh

    2015-01-01

    Purpose: To evaluate the effect of donor and eye bank characteristics on graft rating and clinical outcomes after penetrating keratoplasty (PK) for keratoconus. Methods: This retrospective interventional case series included 252 keratoconic eyes which underwent PK. Donor data included age and sex, cause of death, death-to-preservation time, preservation-to-surgery time, epithelial and stromal status, endothelial cell density (ECD) and morphology, and graft rating. Postoperative outcomes included visual acuity, refractive error, epithelial problems, suture-related complications, graft rejection, and graft transparency. Multivariate regression analysis assessed correlations between donor and eye bank characteristics and graft quality, and postoperative outcomes. Results: Mean recipient and donor age was 29.7 ± 10.0 and 26.2 ± 8.8 years, respectively and mean follow-up period was 66.7 ± 38.5 months. Death-to-preservation time was significantly associated with the presence of graft epithelial sloughing (P = 0.005) and stromal cloudiness (P < 0.001). Donor age significantly influenced ECD (P = 0.02), mean cell area (P = 0.04), and hexagonality (P = 0.01). The presence of epithelial defects on postoperative day 1 correlated significantly with death-to-preservation time (P = 0.004). Graft stromal edema on postoperative day 1 was significantly associated with graft epithelial sloughing (P < 0.001). Postoperative visual and refractive outcomes, complications, and graft survival were not correlated with any donor or eye bank factors. Conclusion: Donor and eye bank variables affected the quality of donor corneas and early postoperative course. However, their long term effect on clinical outcomes, complications, and graft survival were insignificant. PMID:27051479

  14. Immunohistological Evaluation of the Healing Response at the Flap Interface in Patients With LASIK Ectasia Requiring Penetrating Keratoplasty

    PubMed Central

    Esquenazi, Salomon; Esquenazi, Isi; Grunstein, Lev; He, Juicheng; Bazan, Haydee

    2010-01-01

    PURPOSE To evaluate the healing response at the flap interface in corneas with LASIK ectasia that required penetrating keratoplasty (PK). METHODS Corneas of five patients who developed corneal ectasia after LASIK (range: 2.5 to 5 years postoperative) were collected after corneal transplant surgery. The corneas were bisected and processed for conventional histologic analysis and immunofluorescence. RESULTS Light microscopy showed a hypocellular fibrotic scar at the wound margin compared with the adjacent corneal stroma in all eyes. All corneas had positive staining for alpha-smooth muscle actin (SMA), a myofibroblast marker. In one eye, alpha-SMA cells were located in the fibrotic scar region in the area of the semicircular ring of haze along the margin of the LASIK flap corresponding to an area of epithelial ingrowth. In all other eyes, alpha-SMA positive cells were fewer and mainly located in the superficial stroma under the epithelial wound margin surface. Type III collagen was minimal or absent in the central zone and wound margin of all corneas except for the cornea with epithelial ingrowth present in the hypercellular fibrotic scar region. Chondroitin sulfate was stronger in the periphery of the flap wound coinciding with a higher presence of alpha-SMA–positive cells in that region. Positive staining for matrix metalloproteinase 9 (MMP-9) in the paracentral wound margin scar was seen. CONCLUSIONS A wound-healing process characterized by absence of significant fibrosis and myofibroblasts at the wound edge in the flap interface was noted in all keratectatic eyes. However, changes in the composition of collagen and the presence of MMP-9 at the wound edge several years after LASIK indicates active wound remodeling that may explain the ongoing loss of tissue and tendency of the cornea to bulge. PMID:19714799

  15. Changing Practice Patterns and Long-term Outcomes of Endothelial Versus Penetrating Keratoplasty: A Prospective Dutch Registry Study.

    PubMed

    Dickman, Mor M; Peeters, Jean Marie P W U; van den Biggelaar, Frank J H M; Ambergen, Ton A W; van Dongen, Martin C J M; Kruit, Pieter Jan; Nuijts, Rudy M M A

    2016-10-01

    To compare graft survival, best-corrected visual acuity (BCVA), endothelial cell density (ECD), and refraction following penetrating keratoplasty (PK) vs endothelial keratoplasty (EK) for Fuchs endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK). Nonrandomized treatment comparison with national registry data. All consecutive patients undergoing first keratoplasty for FED and PBK between 1998 and 2014 were analyzed, with a maximum follow-up of 5 years (mean ± SD follow-up 39 ± 20 months, range 0-60 months). Graft survival was analyzed using Kaplan-Meier survival curves and Cox regression analysis. BCVA, ECD, and refractive error were compared using linear mixed models. Main outcome measures were graft survival, BCVA, refraction, and ECD. A total of 5115 keratoplasties (PK = 2390; EK = 2725) were identified. Two-year graft survival following EK was lower compared with PK (94.5% vs 96.3%, HR = 1.56, P = .001). Five-year survival was comparable for EK and PK (93.4% vs 89.7%, HR = 0.89, P = .261). EK graft survival improved significantly over time while remaining stable for PK. One-year BCVA was better following EK vs PK (0.34 vs 0.47 logMAR, P < .001). Astigmatism was lower 1 year after EK vs PK (-1.69 vs -3.52 D, P < .001). One-year ECD was lower after EK vs PK (1472 vs 1859 cells/mm(2), P < .001). At 3 years, ECD did not differ between EK and PK. Long-term graft survival after EK and PK is high and comparable despite lower short-term survival for EK. EK graft survival improved over time, suggesting a learning curve. EK results in better BCVA, lower astigmatism, and similar long-term ECD compared with PK for FED and PBK. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. A case of recipient bed melt and wound dehiscence after penetrating keratoplasty and subconjunctival injection of bevacizumab.

    PubMed

    Bhasin, Purendra; Gujar, Prateek; Bhasin, Priyamvada

    2012-11-01

    We describe a case of recipient bed melt and wound dehiscence after uneventful penetrating keratoplasty and subconjunctival injection of bevacizumab. Three weeks postoperatively, the patient presented with limbal ischemia, recipient bed melt, and wound dehiscence corresponding to the area of bevacizumab injection. The melt was managed by application of cyanoacrylate glue along with bandage contact lens. Although the graft survived, there was a problem in re-epithelization. This case highlights the need for further studies to elucidate the therapeutic dose, side effects, and correct timing of using bevacizumab with respect to corneal transplant surgery.

  17. The Results of Toric Intraocular Lens Implantation in Patients With Cataract and High Astigmatism After Penetrating Keratoplasty.

    PubMed

    Müftüoğlu, İlkay Klç; Akova, Yonca Aydn; Egrilmez, Sait; Yilmaz, Suzan Guven

    2016-03-01

    To evaluate the results of toric intraocular lens (IOL) implantation in patients with cataract and postpenetrating keratoplasty astigmatism. Seven eyes of 7 patients with cataract and more than 3.5 diopters (D) astigmatism following penetrating keratoplasty were included in this retrospective case series study. All of the eyes underwent phacoemulsification and Acrysof toric IOL (t5-t9) implantation at least 6 months later than the complete suture removal. Corrected visual acuity (CVA), manifest astigmatism, the keratometry measurements, and complications were assessed. The mean preoperative CVA significantly increased (0.7±0.3 [range: 0.3-1.3] logMAR to 0.1±0.04 [range: 0.05-0.15] logMAR; P<0.05) at mean 8.71±4.11 months after the surgery. The mean preoperative corneal astigmatism and the average manifest refractive astigmatism at the last visit were 5.4±0.9 D (range: 4.25-7 D) and 1.6±0.6 D (range: 0.5-2.5 D), respectively. The mean attempted cylinder correction at spectacle plane was 4.3±0.9 D (range: 2.4-4.7 D) whereas the mean cylinder correction was 4.6±0.5 D (range: 3.9-5.9 D), showing a slightly tendency for overcorrection. All eyes (100%) were within 1 D of predicted residual astigmatism. No complication occurred during the follow-up. Toric IOL implantation seems to be an effective, predictable, and safe procedure in patients with cataract formation and high astigmatism after penetrating keratoplasty.

  18. The effect of vernal keratoconjunctivitis on clinical outcomes of penetrating keratoplasty for keratoconus.

    PubMed

    Egrilmez, Sait; Sahin, Sevinc; Yagci, Ayse

    2004-12-01

    Although good visual results and low complication rates are commonly reported following penetrating keratoplasty (PKP) in eyes with keratoconus, the outcome of PKP in eyes with keratoconus and concomitant vernal keratoconjunctivitis (VKC) has not been well documented. We performed a study to compare the outcome and relative risk factors of PKP for keratoconus with and withoutVKC. Review of the medical records of all patients who underwent PKP for keratoconus at a university-affiliated hospital in Izmir,Turkey, from Nov. 1, 1991, to Jan. 31, 2002. Only eyes that had been followed for at least 18 months postoperatively were included in the study. Twenty-three eyes of 19 patients (14 males and 5 females) had keratoconus with VKC, and 65 eyes of 57 patients (33 males and 24 females) had keratoconus alone. We compared clinical outcomes and complications between the two groups. The mean length of follow-up was 34.0 months (standard deviation [SD] 16.3 months) (range 18-67 months) in the eyes with comitant VKC and 41.0 (SD 19.8) months (range 18-98 months) in the eyes with keratoconus alone. During the follow-up period, 2.35 (SD 1.90) suture-removal sessions for loosened sutures were performed in the eyes with VKC, compared with 1.34 (SD 1.69) sessions in the eyes with keratoconus alone (p = 0.016). Steroid-induced glaucoma developed in two eyes (8.7%) in theVKC group and in three eyes (4.6%) in the keratoconus-alone group (p = 0.603); the rates of steroid-induced cataract were four (17.4%) and two (3.1%) respectively (p = 0.038). The average final best-corrected visual acuity was 20/22 (range 20/50 to 20/20) in the eyes with VKC and 20/23 (range 20/60 to 20/20) in the eyes with keratoconus alone. The clinical outcome of PKP in eyes with keratoconus and VKC is comparable to that in eyes with keratoconus alone. However, because complications such as prematurely loosened sutures and steroid-induced cataract are more common in the coexistence of VKC, closer monitoring is

  19. Photo cross-linkable Biodendrimers as ophthalmic adhesives for central lacerations and penetrating keratoplasties.

    PubMed

    Degoricija, Lovorka; Johnson, C Starck; Wathier, Michel; Kim, Terry; Grinstaff, Mark W

    2007-05-01

    Biodendrimer-based hydrogel adhesives were derived from biocompatible building blocks and poly(ethylene glycol) of 3,400, 10,000 and 20,000 g/mole. The leaking pressures were determined for these adhesives when used to seal 4.1-mm central lacerations and penetrating keratoplasties (PKPs) in enucleated porcine eyes. Three biodendrimers, ([G1]-PGLSA-MA)(2)-PEG(3,400), ([G1]-PGLSA-MA)(2)-PEG(10,000), and ([G1]-PGLSA-MA)(2)-PEG(20,000), at a range of weight percents were each photo cross-linked in the presence of a photo-initiator to form a hydrated network. These biodendrimer-based adhesives were applied directly to a 4.1-mm linear central laceration. In a PKP, the corneal button was initially secured with 8 or 16 sutures and then sealed with the adhesive. For the 4.1-mm central lacerations, the ([G1]-PGLSA-MA)(2)-PEG(3,400) at 20% and 40% wt/vol, the ([G1]-PGLSA-MA)(2)-PEG(10,000) at 10 and 20% wt/vol, and the ([G1]-PGLSA-MA)(2)-PEG(20,000) at 20% wt/vol held to leaking pressures above 200 mm Hg. In the autograft with 16 sutures, the 20% wt/vol of the ([G1]-PGLSA-MA)(2)-PEG(3,400), ([G1]-PGLSA-MA)(2)-PEG(10,000), and ([G1]-PGLSA-MA)(2)-PEG(20,000) held to a pressure at or above 100 mm Hg. In the autograft with eight sutures, the ([G1]-PGLSA-MA)(2)-PEG(10,000) and ([G1]-PGLSA-MA)(2)-PEG(20,000) formulations at 20% wt/vol held to leaking pressures of 85 +/- 22 and 80 +/- 30 mm Hg, respectively. The 10% wt/vol ([G1]-PGLSA-MA)(2)-PEG(10,000) formulation withheld leaking pressures above 200 mm Hg when used to secure a 4.1 mm central laceration. The 20% wt/vol ([G1]-PGLSA-MA)(2)-PEG(10,000) and ([G1]-PGLSA-MA)(2)-PEG(20,000) formulations, with 8 or 16 sutures, secured the PKP well above normal IOP. Biodendrimer-based adhesives are of potential use for repairing corneal wounds.

  20. The impact of donor age and endothelial cell density on graft survival following penetrating keratoplasty.

    PubMed

    Wakefield, M J; Armitage, W J; Jones, M N A; Kaye, S B; Larkin, D F P; Tole, D; Prydal, J

    2016-07-01

    To determine if donor age and preoperative endothelial cell density (ECD) affect corneal endothelial failure following penetrating keratoplasty (PK). Preoperative and postoperative data for PKs performed in the UK between April 1999 and March 2012 were analysed. Donor age was split into three groups (0-60, 61-75 and >75 years) and donor ECD was split into three groups (≤2400, 2401-2600 and >2600 cells/mm(2)). Cox proportional hazards regression was used to determine whether the selected subgroups of donor age and donor ECD have an impact on endothelial failure and a systematic analysis of the interaction between donor ECD and donor age was conducted. The analysis was stratified for primary corneal diagnosis (Fuchs endothelial dystrophy (FED), pseudophakic bullous keratopathy (PBK) and other) and corrected for potentially confounding factors (human leukocyte antigen matching, donor trephine diameter, deep vascularisation, the occurrence of reversible rejection episodes and receipt of systemic antiviral medication, long-term steroids or other immunosuppressive agents). A total of 9415 patients, from the National Health Service Blood and Transplant UK Transplant Registry, who received their first PK for visual reasons were included in this study. The overall 5-year graft survival rate due to endothelial failure was 89%. Survival rates in recipients with FED, PBK and 'all other indications' were 95%, 83% and 89%, respectively. Our analysis shows that donor ECD did not affect outcome following corneal graft within the preselected categories, irrespective of diagnosis and after allowing for any potential confounding factors. Furthermore, HRs for each level of donor ECD, relative to >2600 cells/mm(2), for each combination of age group and indication, were not statistically significant. We were unable to detect a significant effect of donor age, up to 90 years, and preoperative donor ECD, above the lower limit of 2200 cells/mm(2), on endothelial failure at 5

  1. Comparison of Long-term Clinical Outcomes between Descemet's Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty in Patients with Bullous Keratopathy

    PubMed Central

    Kim, Sung Eun; Lim, Sung A; Byun, Yong-Soo

    2016-01-01

    Purpose To compare 2-year clinical outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK) in patients with bullous keratopathy. Methods A retrospective chart review was performed to obtain 2 years of follow-up data of DSAEK or PK at a single center from March 2009 to September 2012. The study comprised 15 eyes of DSAEK and 11 eyes of PK. Outcome measures included best-corrected visual acuity (BCVA), spherical and keratometric changes, central corneal thickness, endothelial cell density, intraocular pressure, and postoperative complications. Graft survival rate was assessed by Kaplan-Meier survival analysis. Results There were no differences in patient baseline characteristics between the two groups. At postoperative 2 years, better BCVA of 0.69 ± 0.51 logarithm of the minimum angle of resolution (logMAR) was found after DSAEK compared to 0.88 ± 0.48 logMAR after PK. Refractive cylinder in DSAEK and PK was −2.60 ± 1.53 and −6.00 ± 1.05 diopters (D), respectively, and keratometric cylinder was 3.27 ± 3.70 and 6.34 ± 3.51 D, respectively, at postoperative 2 years. The difference of mean spherical equivalents between postoperative 1 month and 2 years was 0.84 D after DSAEK and 2.05 D after PK. A hyperopic shift of 1.17 D was present after 2 years of DSAEK. The mean endothelial cell density at postoperative 2 years was 1,548 ± 456 cells/mm2 for DSAEK and 1,052 ± 567 cells/mm2 for PK, with a cell loss of 19.96% vs. 52.38%, respectively when compared to postoperative 1 month. No significant difference in central corneal thickness was found between DSAEK and PK (592 ± 75 vs. 563 ± 90 µm, respectively). Finally, the 2-year survival rate did not differ significantly between DSAEK and PK (93.3% vs. 81.8%, respectively, p = 0.344). Conclusions Compared to PK, DSAEK provided more stable refractive errors with better visual outcome, lower endothelial cell loss, and a lower rate of graft rejection at

  2. Graft Rejection Rate and Graft Failure Rate of Penetrating Keratoplasty (PKP) vs Lamellar Procedures: A Systematic Review

    PubMed Central

    Akanda, Zarique Z.; Naeem, Abdul; Russell, Elizabeth; Belrose, Jillian; Si, Francie F.; Hodge, William G.

    2015-01-01

    Purpose The aim of our investigation was to conduct a quantitative meta-analysis of the present world literature comparing the major surgical outcomes of penetrating keratoplasty (PKP) to lamellar procedures. Our goal is that clinicians, eye bank administrators, and health policy makers will be able to utilize this study in implementing decisions in regards to corneal transplantation. Methods Pooled measures of association were with odds ratios and because of study heterogeneity, the pooled effects were assumed to follow a random effects model (DerSimonian-Laird). The comparisons were between 1) PKP’s and all lamellar procedures (anterior AND posterior) and then 2) between PKP’s and all anterior lamellar procedures and 3) PKP and all posterior lamellar procedures. Results For PKP vs anterior lamellar procedures, the pooled odds ratio for rejection of PKP over lamellar keratoplasty (LK) was 3.56 (95% CI: 1.76-7.20) and for outright failure, the pooled odds ratio of PKP failure vs LK was 2.85 (95% CI: 0.84-9.66). For posterior lamellar procedures, the pooled odds ratio for rejection of PKP over LK was 1.52 (95% CI: 1.00-2.32). The pooled odds ratio for outright failure of PKP over posterior lamellar procedures was 2.09 (95% CI: 0.57-7.59). The follow up time was significantly longer for full transplants than for lamellar procedures. Conclusions For both anterior and posterior lamellar procedures, the odds ratios comparing rejection of full transplants to lamellar procedures (both anterior and posterior individually) were significantly higher in the PKP group. For outright failure, the PKP group also had a higher risk of failure than the lamellar groups but this was not statistically significant in either instance (anterior or posterior). Some of the clinical differences benefitting lamellar procedures may at least be partly explained by follow up time differences between groups and this needs to be accounted for more rigorously in future studies. PMID:25781319

  3. [Corneal astigmatism after penetrating keratoplasty with direct and indirect sutures (author's transl)].

    PubMed

    Klemen, U M

    1976-06-01

    After a full thickness optic keratoplasty the corneal astigmatism of 116 eyes was checked. 72 cases had been operated on with indirect, 44 with direct sutures. Up to the sixth month after the operation the astigmatism was found to be equally distributed between 0.75 and 12 dpt and until the end of the second year between 0.75 and 8 dpt. Neither the way of suturing nor the diameter of the graft nor the kind of corneal lesion had any influence on the postoperative astigmatism. After six months, the height and the axis of the astigmatism remained approximately constant; however, in four cases of keratokonus followed up for nineteen years the astigmatism gradually increased.

  4. Corneal shrinkage induced by nonmechanical Q-switched erbium:YAG laser trephination for penetrating keratoplasty in porcine eyes.

    PubMed

    Stojkovic, Milenko; Seitz, Berthold; Küchle, Michael; Langenbucher, Achim; Viestenz, Arne; Viestenz, Anja; Hofmann-Rummelt, Carmen; Naumann, Gottfried O H

    2003-08-01

    To assess the degree of corneal diameter shrinkage induced by Q-switched mid-infrared laser corneal trephination for penetrating keratoplasty in an experimental model. Corneal trephination was performed in 80 enucleated porcine eyes fixed in a holder centered on an automated globe rotation device, by Q-switched (2.94 microm) Er:YAG laser along open masks. Four types of masks were used to protect the underlying corneal tissue: metal masks (donor and recipient) and ceramic masks (donor and recipient). Two spot diameters (0.65 mm and 0.96 mm) were combined with two energy settings (40 mJ/pulse and 50 mJ/pulse) for each of the masks used. Repetition rate was fixed at 5 Hz. Diameters of donor buttons/recipient beds (horizontal and vertical) were measured immediately after the trephination and compared to the given mask size. Minimum corneal shrinkage was found in the recipient metal mask group (mean +/- SD=0.3+/-0.4%) with 50 mJ pulse energy and 0.65 mm spot diameter (in the horizontal diameter), while the maximum shrinkage (5.3+/-2.8%) was found in the donor metal mask group with 50 mJ pulse energy and 0.96 mm spot diameter. Corneal shrinkage was less pronounced in recipient beds than in donor buttons (P<0.01). The differences in shrinkage between the use of ceramic and metal masks were insignificant (P>0.05). Mean induced corneal diameter discrepancies between the donor button and the recipient bed (with metal and ceramic masks) were 2.5% and 2.5% in vertical diameter and 3.4% and 2.4% in horizontal diameter. The Q-switched Er:YAG laser experimental corneal trephination for penetrating keratoplasty may induce minor degrees of corneal diameter shrinkage in donor buttons and recipient openings. Oversizing of donor masks by 0.25-0.35 mm (i.e. 3-4% of graft size) may be a valid option to avoid refractive consequences.

  5. The Effect of Donor Diabetes History on Graft Failure and Endothelial Cell Density Ten Years after Penetrating Keratoplasty

    PubMed Central

    Lass, Jonathan H.; Riddlesworth, Tonya D.; Gal, Robin L.; Kollman, Craig; Benetz, Beth A.; Price, Francis W.; Sugar, Alan; Terry, Mark A.; Soper, Mark; Beck, Roy W.

    2014-01-01

    Objective To examine the long term effect of donor diabetes history on graft failure and endothelial cell density (ECD) after penetrating keratoplasty (PKP) in the Cornea Donor Study Design Multi-center prospective, double-masked, controlled clinical trial Participants 1090 subjects undergoing PKP for a moderate risk condition, principally Fuchs’ dystrophy or pseudophakic/aphakic corneal edema (PACE), were enrolled by 105 surgeons from 80 clinical sites in the United States. Methods Corneas from donors 12 to 75 years old were assigned by 43 eye banks to participants without respect to recipient factors. Donor and recipient diabetes status was determined from existing medical records. Images of the central endothelium were obtained preoperatively (baseline) and at intervals for ten years postoperatively and analyzed by a central image analysis reading center to determine ECD. Main Outcome Measure(s) Time to graft failure (regraft or cloudy cornea for 3 consecutive months) and ECD. Results There was no statistically significant association of donor diabetes history with 10-year graft failure, baseline ECD, 10-year ECD or ECD values longitudinally over time in unadjusted analyses nor after adjusting for donor age and other significant covariates. The 10-year graft failure rate was 23% in the 199 cases receiving a cornea from a donor with diabetes versus 26% in the 891 cases receiving a cornea from a donor without diabetes (95% confidence interval for the difference: −10% to +6%; unadjusted p = 0.60). Baseline ECD (p=0.71), 10-year ECD (p>0.99), and changes in ECD over 10 years (p=0.86) were similar comparing donor diabetes and no-diabetes groups. Conclusions and Relevance The study results do not suggest an association between donor diabetes and PKP outcome. However, the assessment of donor diabetes was imprecise and based on historical data only. The increasing frequency of diabetes in the aging population in the United States affects the donor pool, thus the

  6. Laser-assisted In Situ Keratomileusis for Correction of Astigmatism and Increasing Contact Lens Tolerance after Penetrating Keratoplasty

    PubMed Central

    Park, Chang-Hyun; Kim, Su-Young

    2014-01-01

    Purpose To determine effectiveness of laser-assisted in situ keratomileusis (LASIK) in the treatment of astigmatism following penetrating keratoplasty (PK). Methods We performed a retrospective review of medical records of patients who underwent LASIK following PK and had over 1 year of follow-up data. Results Twenty-six patients (26 pairs of eyes) underwent LASIK following PK. Mean age of the patients at the time of LASIK was 40.7 years (range, 26 to 72 years). Following LASIK, the mean cylinder was reduced by 2.4 diopters and mean reduction of cylinder after LASIK was 65.4% from the preoperative values at the last follow-up visit. Uncorrected visual acuity became 20 / 50 or better in 69.2% of the eyes after LASIK. Best-corrected visual acuity became 20 / 50 or better in 73.1% of the eyes after LASIK. All of them were intolerable to contact lenses before LASIK. After LASIK, 6 pairs (23.1%) did not need to use contact lenses and 18 pairs (69.2%) were tolerable to using contact lenses or spectacles. There were no significant endothelial cell density changes 12 months after LASIK (p = 0.239). Conclusions LASIK is effective in the treatment of astigmatism following PK and increases contact lens and spectacle tolerance. PMID:25276076

  7. Corneal endothelial cell loss in post-penetrating keratoplasty patients after cataract surgery: phacoemulsification versus planned extracapsular cataract extraction.

    PubMed

    Acar, Banu Torun; Buttanri, Ibrahim Bulent; Sevim, Mehmet Sahin; Acar, Suphi

    2011-08-01

    To compare the changes in endothelial cell density (ECD) in post-penetrating keratoplasty (PKP) patients after cataract extraction with phacoemulsification or planned extracapsular cataract extraction (ECCE). Haydarpasa Numune Education and Research Hospital, Ophthalmology Clinic, Istanbul, Turkey. Clinical trial. Eyes with hard nuclear cataract that had previous PKP were randomly assigned to have phacoemulsification or ECCE. Noncontact specular microscopy was performed preoperatively and 1, 3, and 6 months postoperatively. Twenty-six eyes of 26 patients were enrolled (14 phacoemulsification; 12 ECCE). Six months postoperatively, the mean corneal ECD was statistically significantly lower in the phacoemulsification group (1869.50 cells/mm(2) ± 158.05 [SD]) than in the ECCE group (1996.00 ± 127.96 cells/mm(2)) (P=.024). The mean percentage of endothelial cell loss at 6 months was 20.3% and 12.7%, respectively (P<.05). In both groups, there was no significant difference in the percentage hexagonality between preoperatively and postoperatively (P>.05). Extracapsular cataract extraction seemed to cause less endothelial cell damage than phacoemulsification in post-PKP patients with hard nuclear cataract. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Management of Extreme Ametropia after Penetrating Keratoplasty: A Series of Surgical Procedures for High Myopia and Astigmatism

    PubMed Central

    Valdez-Garcia, Jorge E.; Cueto-Gómez, Juan J.; Lozano-Ramírez, Juan F.; Tamez-Peña, Alejandro E.

    2014-01-01

    A series of surgical interventions – relaxing corneal incisions, intraocular lens, and intrastromal rings – were used to correct a case of extreme ametropia in a thin cornea after a penetrating keratoplasty in an 18-year-old patient who presented with a −10.25 −8.50 × 120 preoperative refraction and 20/200 best-corrected visual acuity (BCVA). After a series of surgical procedures, the patient's BCVA in his left eye improved to 20/30 with +0.50 −1.00 × 170, the slit lamp examination showed no significant findings, and the patient's visual complaints disappeared. At the 1-year follow-up, the BCVA was 20/25, without visual complaints. The process of individualizing the surgical procedure in the present case was employed in an outcome-based approach, that is, the next surgical procedure was defined after the surgery and postoperative evaluation. The patient did not present complications during the follow-up period of 2.5 years. PMID:25232339

  9. Systemic Immunosuppression in High-Risk Penetrating Keratoplasty: A Systematic Review

    PubMed Central

    Bali, Shveta; Filek, Richard; Si, Francie; Hodge, William

    2016-01-01

    Cornea transplantation has a high success rate and typically only requires topical immunomodulation. However, in high-risk cases, systemic immunosuppression can be used. We conducted a systematic review on the efficacy and side effects of systemic immunosuppression for high-risk cornea transplantation. The study population was 18 years old or older with a high-risk transplant (two or more clock hours of cornea vascularization or a previous failed graft or a graft needed because of herpes simplex keratitis). A comprehensive search strategy was performed with the help of an information specialist and content experts from ophthalmology. All study designs were accepted for assessment. Level 1 and level 2 screening was performed by two reviewers followed by data abstraction. Forest plots were created whenever possible to synthesize treatment effects. Quality assessment was done with a Downs and Blacks score. From 1,150 articles, 29 were ultimately used for data abstraction. The odds ratios (ORs) for clear graft survival in cyclosporine and controls were 2.43 (95% CI: 1.00 - 5.88) and 3.64 (95% CI: 1.48 - 8.91) for rejection free episodes. Mycophenolate mofetil (MMF) significantly improved the rejection free graft survival rates at 1 year (OR: 4.05, 95% CI: 1.83 - 8.96). The overall results suggested that both systemic cyclosporine and MMF improved 1-year rejection free graft survival in high-risk keratoplasty. Cyclosporine also significantly improved clear graft survival rates at 1 year; however, there were insufficient data to analyze the same in the MMF group. Higher quality studies are needed to understand this issue better. PMID:26985246

  10. The effect of donor diabetes history on graft failure and endothelial cell density 10 years after penetrating keratoplasty.

    PubMed

    Lass, Jonathan H; Riddlesworth, Tonya D; Gal, Robin L; Kollman, Craig; Benetz, Beth A; Price, Francis W; Sugar, Alan; Terry, Mark A; Soper, Mark; Beck, Roy W

    2015-03-01

    To examine the long-term effect of donor diabetes history on graft failure and endothelial cell density (ECD) after penetrating keratoplasty (PK) in the Cornea Donor Study. Multicenter, prospective, double-masked, controlled clinical trial. One thousand ninety subjects undergoing PK for a moderate risk condition, principally Fuchs' dystrophy or pseudophakic or aphakic corneal edema, were enrolled by 105 surgeons from 80 clinical sites in the United States. Corneas from donors 12 to 75 years of age were assigned by 43 eye banks to participants without respect to recipient factors. Donor and recipient diabetes status was determined from existing medical records. Images of the central endothelium were obtained before surgery (baseline) and at intervals for 10 years after surgery and were analyzed by a central image analysis reading center to determine ECD. Time to graft failure (regraft or cloudy cornea for 3 consecutive months) and ECD. There was no statistically significant association of donor diabetes history with 10-year graft failure, baseline ECD, 10-year ECD, or ECD values longitudinally over time in unadjusted analyses, nor after adjusting for donor age and other significant covariates. The 10-year graft failure rate was 23% in the 199 patients receiving a cornea from a donor with diabetes versus 26% in the 891 patients receiving a cornea from a donor without diabetes (95% confidence interval for the difference, -10% to 6%; unadjusted P=0.60). Baseline ECD (P=0.71), 10-year ECD (P>0.99), and changes in ECD over 10 years (P=0.86) were similar comparing donor groups with and without diabetes. The study results do not suggest an association between donor diabetes and PK outcome. However, the assessment of donor diabetes was imprecise and based on historical data only. The increasing frequency of diabetes in the aging population in the United States affects the donor pool. Thus, the impact of donor diabetes on long-term endothelial health after PK or endothelial

  11. [Shunt tube implantation combining amniotic membrane transplantation and implantation of Molteno implant for glaucoma after penetrating keratoplasty].

    PubMed

    Liu, Y; Li, H; Chen, J

    2000-06-01

    To investigate the therapeutic effect of aqueous humor shunt implants with amniotic membrane transplantation on intractable glaucoma. Glaucoma was induced in rabbits by the injection of alpha-chymotrypsin into the posterior chamber of the eyes. The rabbits were divided into four groups. Group A: control group, Group B: single shunt tube group, Group C: shunt tube with amniotic membrane transplantation group, Group D: shunt tube with amniotic supporter and amniotic membrane transplantation group. The intraocular pressure(IOP), histology and filterable ability of the tissue around the tubes were studied. The therapeutic effect of the three methods for the glaucoma was compared. From 1998 to 1999, 42 eyes of 41 patients with uncontrolled glacoma after penetrating keratoplasty were randomly assigned into two groups. One group (12 eyes) underwent implantation of shunt tube combining transplantation of amniotic membrane. The other group underwent implantation of a single plate Molteno implant. Clinical records were reviewed to ascertain postoperative IOP, visual acuities, number of medications. The IOP elevated after the operation and reached at the peak on the third day for all groups and then dropped slowly. The IOP was 33.34 +/- 5.54 mmHg (1 mmHg = 0.133 kPa) for Group A and 27.88 +/- 8.86 mmHg for Group B three months after the operation. There was no statistical difference between the two groups (P = 0.274). The IOP was 22.33 +/- 3.73 mmHg for Group C and there was statistical significant difference between Group C and Group A (P = 0.02) and no difference between Group C and Group B (P = 0.113). The IOP was 15.74 +/- 2.94 mmHg for Group D and there was statistical significant difference between Group D and Group A (P = 0.001) and Group B (P = 0.036). There was no difference between Group D and Group C (P = 0.09). The study of horseradish peroxidase penetrability indicated that there was peroxidase in the tissues around the tube with amniotic membrane transplantation

  12. Preliminary study of the effect of FK506 nanospheric-suspension eye drops on rejection of penetrating keratoplasty.

    PubMed

    Fei, Wen-Lei; Chen, Jia-Qi; Yuan, Jin; Quan, Da-Ping; Zhou, Shi-You

    2008-04-01

    The aim of this study was to investigate the effect of a topical FK506 nanospheric suspension in a rat model of penetrating keratoplasty. FK506 nanospheres were prepared by using a biodegradable poly (lactic-co-glycolic acid) copolymer (PLGA). Its distribution in the eye and blood after a single instillation was examined in rabbits. Sprague-Dawley (SD) rats received corneal heterografts and were topically treated with phosphate-buffered saline (PBS), PLGA, FK-506 0.01% (nanospheres), or dexamethasone 0.05% solutions twice a day for 28 days. Rejection index and graft-survival time were recorded and compared between the four groups. Three grafts were collected at different time points for immunohistochemical studies. In the cornea, the FK-506 concentration reached its peak within 1 h of a single eye-drop instillation and then decreased by half (1667.85 +/- 611.87 ng/g) at 8 h. FK-506 cannot be detected in rabbit blood. There were significant differences in the graft-survival time between the FK-506 nanosphere group (15.09 +/- 4.81 days) and the other three groups [PBS (7.90 +/- 1.20, t = -4.594, P < 0.001), PLGA (8.44 +/- 0.88, t = - 4.074, P = 0.001) and dexamethasone (10.44 +/- 1.42, t = -2.790, P = 0.012)]. The rejected corneas in the FK506 nanosphere group showed significantly fewer CD4, CD8, CD68, CD79, vascular endothelial growth factor, ICAM, and tumor growth factor-beta(1)-positive cells than those in the other groups. FK506 0.01% nanospheric-suspension eye drops delayed the occurrence of corneal allograft rejection and prolonged allograft survival time. The FK506 nanospheres may be valuable in suppressing corneal graft rejection.

  13. Do topical ophthalmic corticosteroids suppress the hypothalmic-pituitary-adrenal axis in post-penetrating keratoplasty patients?

    PubMed Central

    Sandhu, S S; Smith, J M; Doherty, M; James, A; Figueiredo, F C

    2012-01-01

    Purpose To establish whether hypothalmic-pituitary-adrenal axis suppression is possible secondary to long-term topical ophthalmic corticosteroid use in patients who have undergone penetrating keratoplasty (PKP). Methods Patients who had undergone a PKP and had been using corticosteroid-based eye drops continuously for more than 6 months, with no history of concomitant steroid (oral, inhaled, or cutaneous) use, were included within the study. A low-dose short Synacthen (LDSST) test was performed in each patient followed later by a short Synacthen test (SST). The mean SST and LDSST after 30 min were calculated along with their corresponding 95% confidence intervals (CIs). Correlation between both baseline SST and baseline LDSST with duration of treatment was determined using Spearman's correlation. Results In all, 20 patients were included within the study. The mean duration treatment was 28.2 months (range 11–96 months). All patients had normal baseline cortisol levels in both SST and LDSST tests. The mean 30 min SST was 753.8 nmol/l (95%CI: 696.6 nmol/l, 811.0 nmol/l) and no patients displayed inadequate adrenal response. The mean 30 min LDSST was 709.8 nmol/l (95%CI: 665.1 nmol/l, 754.5 nmol/l) and only one patient had an inadequate adrenal response. There was no correlation between baseline SST or LDSST and duration of treatment. Conclusions This study found no evidence that patients using continuous long-term corticosteroid eye drops after PKP experienced inadequate adrenal response. We did not find any evidence of a negative correlation between length of treatment and SST or LDSST measurements at baseline. PMID:22344184

  14. Total protein concentration and T-cell suppression activity of aqueous humour before and after penetrating keratoplasty

    PubMed Central

    Mo, J-S; Maier, P; Böhringer, D; Reinshagen, H; Sundmacher, R; Reinhard, T

    2012-01-01

    Purpose We wished to determine whether immune privilege parameters assayed in aqueous humour (AqH) are relevant to the fate of penetrating keratoplasty (PK) in humans. Methods AqH was collected in 28 patients before PK (prospective cohort), in 6 patients with no history of graft rejection undergoing cataract surgery after PK (acceptors), in another 6 patients undergoing treatment of an acute endothelial immune reaction (rejectors), and in 65 controls undergoing uncomplicated cataract extraction. AqH was tested for total protein concentration and the ability to suppress T-cell activation. Results AqH protein concentrations of acceptors and rejectors post-PK were elevated (2.7±0.8 and 2.7±0.7 mg/ml, respectively) compared with pre-PK AqH level and cataract controls (1.0±0.1 mg/ml, P=0.01). All AqH samples suppressed T-cell activation, irrespective of source and timing of AqH removal. Conclusion Assays of immune privilege markers in AqH suggest that PK surgery may result in a sustained loss of integrity of the blood–aqueous barrier. Although trends were evident, values of immune privilege markers determined pre- and post-PK were not statistically significantly different between the study groups. However, further prospective studies determining additional immune privilege markers have to be conducted in order to find out whether these markers might serve as predictive parameters for immune reactions following PK. PMID:22094304

  15. Blood-aqueous barrier breakdown after penetrating keratoplasty with simultaneous extracapsular cataract extraction and posterior chamber lens implantation.

    PubMed

    Nguyen, N X; Langenbucher, A; Seitz, B; Graupner, M; Cursiefen, C; Küchle, M; Naumann, G O

    2001-02-01

    The purpose of this study was to quantify breakdown of the blood-aqueous barrier (BAB) following penetrating keratoplasty (PK) with simultaneous extracapsular cataract extraction and posterior chamber lens implantation (triple procedure) and compare it with the alterations following PK only. This study included 72 eyes after triple procedure and 227 eyes after PK only. The diagnosis for PK was Fuchs dystrophy in 39%, keratokonus in 44%, stromal corneal dystrophy in 3% and avascular corneal scars in 6% of cases. The postoperative topical steroid treatment was standardized in both groups. Aqueous flare was quantified using the laser flare-cell meter (FC-1000, Kowa) at defined postoperative intervals (10 days, 6 weeks, then every 3 months until 1 year postoperatively). Patients with conditions associated with impairment of the BAB were excluded from the study. In the early postoperative course, aqueous flare values (photon counts/ms) were significantly higher in patients with triple procedure (21.9 +/- 11.0) than in patients with PK only (9.8 +/- 3.2; P = 0.001). At 6 weeks postoperatively, aqueous flare returned to normal levels in patients after PK only (5.2 +/- 2.3), whereas patients with triple procedure still showed significantly increased flare values (10.8 +/- 5.6; P = 0.01). At 6 months postoperatively, aqueous flare values of patients with triple had returned to normal levels (6.8 +/- 3.8) and did not differ significantly from those after PK only (5.2 +/- 1.9; P = 0.09). Our results indicate that triple procedure causes a more extensive and longer-lasting breakdown of the blood-aqueous barrier than PK only. Quantification of aqueous flare with the laser flare-cell meter is useful in the postoperative follow-up after triple procedure. Further studies are required to investigate the clinical relevance of BAB breakdown on endothelial cell count and the incidence of subsequent immunological graft rejection.

  16. In Vivo Confocal Microscopic Imaging of the Cornea After Femtosecond and Excimer Laser-assisted Penetrating Keratoplasty.

    PubMed

    Resch, Miklós D; Zemova, Elena; Marsovszky, László; Szentmáry, Nóra; Bauer, Florian; Daas, Loay; Pattmöller, Max; El-Husseiny, Moatasem; Németh, János; Nagy, Zoltán Z; Seitz, Berthold

    2015-09-01

    To examine the microstructure of the cornea after excimer and femtosecond laser-assisted penetrating keratoplasty (ELAK and FLAK) in eyes with Fuchs' dystrophy and keratoconus. Fifty-seven patients were divided into four groups according to corneal disease and surgical technique: Fuchs' dystrophy and ELAK (n = 9; mean age: 70.4 ± 10.6 years); Fuchs' dystrophy and FLAK (n = 13; mean age: 64.3 ± 11.2 years); keratoconus and ELAK (n = 9; mean age: 47.4 ± 13.9 years); and keratoconus and FLAK (n = 9; mean age: 43.5 ± 13.8 years). The control group comprised individuals without ocular disease (n = 17; mean age: 39.9 ± 17.3 years). In vivo investigation of the corneal graft and graft-host junction zone was performed with confocal corneal microscopy. All corneal grafts were transparent and no rejection reaction could be observed during the follow-up period. Confocal microscopy revealed no difference in basal epithelial cell density compared to controls. Anterior keratocyte density was lower than in the control group (818 ± 131 cells/mm(2)) in all four treatment groups (596 ± 174, 586 ± 113, 529 ± 75, 552 ± 91 cells/mm(2)). Langerhans cells could barely be seen; there was no difference in the cutting edge configuration and wound integrity. In vivo confocal microscopy provided evidence that good alignment of graft-host junction could be created with both techniques. The excimer laser was not inferior to the femtosecond laser in performing corneal cuts. The low density of Langerhans cells revealed well-controlled cellular immunological response and sustained corneal integrity in both laser groups. Copyright 2015, SLACK Incorporated.

  17. Safety and efficacy of femtosecond laser-assisted arcuate keratotomy to treat irregular astigmatism after penetrating keratoplasty.

    PubMed

    Fadlallah, Ali; Mehanna, Chadi; Saragoussi, Jean-Jacques; Chelala, Elias; Amari, Belkacem; Legeais, Jean-Marc

    2015-06-01

    To determine the refractive efficacy, predictability, stability, and complication rate of Intralase femtosecond laser-assisted astigmatic keratotomy (AK) for irregular astigmatism after penetrating keratoplasty (PKP). Ophthalmology Department, Hôtel-Dieu, Paris, France. Retrospective case series. Femtosecond laser-assisted AK was performed to treat high irregular astigmatism (>5.0 diopters [D]) after PKP. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, vector analysis, and complications were evaluated. The study evaluated 62 eyes of 57 patients over a mean follow-up of 28 months ± 3.5 (SD). Preoperatively, the mean CDVA was 0.51 ± 0.26 logMAR and the mean UDVA was 0.98 ± 0.24 logMAR; 6 months postoperatively, the mean CDVA and UDVA improved to 0.40 ± 0.22 logMAR and 0.60 ± 0.2 logMAR, respectively (both P < .01). The mean preoperative absolute astigmatism was 7.1 ± 1.72 D; 6 months postoperatively, the mean refractive astigmatism was 2.6 ± 2.4 D (P < .001). The UDVA, CDVA, and astigmatism remained stable up to the end of follow-up. The efficacy index was 0.81 at 6 months and 0.67 at 2 years. There were 2 cases of microperforation, 3 cases of infectious keratitis, 3 graft rejection episodes, and 1 case of endophthalmitis. Overcorrection occurred in 12 eyes. Femtosecond laser-assisted AK was effective in reducing irregular astigmatism after PKP. Predictability of astigmatism correction is variable over time with a decrease in the efficacy index 2 years postoperatively. Refinement of the treatment nomogram for femtosecond laser-assisted AK for high astigmatism after PKP remains a major issue. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. Efficacy and safety of long-term corticosteroid eye drops after penetrating keratoplasty: a prospective, randomized, clinical trial.

    PubMed

    Shimazaki, Jun; Iseda, Ayumi; Satake, Yoshiyuki; Shimazaki-Den, Seika

    2012-04-01

    Endothelial rejection remains a major cause of graft failure after penetrating keratoplasty (PKP). Topical corticosteroids are the gold standard for preventing rejection; however, protocols for corticosteroid treatment have been diverse. The aim of the present study was to examine the efficacy and safety of long-term use of corticosteroid eye drops after PKP in a randomized, clinical trial. Randomized, nonblinded, clinical trial. We enrolled 42 patients (21 males and 21 females) with a mean age of 65.3 years who underwent PKP and maintained graft clarity for >1 year with topical steroid eye drops. Patients were randomly assigned to 1 of 2 groups: Administration of 0.1% fluorometholone 3 times a day (steroid group) or discontinuation of steroid eye drops (no steroid group). All patients were followed for 12 months. Proportion of eyes without endothelial rejection and the proportion of eyes with clear grafts and the incidence of local or systemic side effects. Of the initial 42 patients, 4 in the steroid group and 6 in the no steroid group did not complete the trial. Of the patients who completed the trial, 1 patient in the steroid group and 6 in the no steroid group developed endothelial rejection at an average of 5.2±4.5 (mean ± standard deviation) months after study enrollment. The difference in the incidence of rejection between groups was found to be significant by both chi-square (P = 0.027) and Kaplan-Meier analyses (log-rank test, P = 0.032). No difference was observed between the 2 groups in visual acuity, intraocular pressure, epithelial damage, tear-film break-up time, cataract progression, infection, or incidence of systemic side effects. Prolonged use of 0.1% fluorometholone was beneficial for the prevention of rejection after PKP. Because no adverse consequences were noted, we recommend continuing use of the low-dose corticosteroids, even in non-high-risk cases. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights

  19. [Impact of intracameral pressure on donor cut angles in nonmechanical Er:YAG laser trephination for penetrating keratoplasty].

    PubMed

    Sauer, Renate; Seitz, Berthold; Mardin, Christian; Langenbucher, Achim; Hofmann-Rummelt, Carmen; Viestenz, Anja; Küchle, Michael; Naumann, Gottfried O H

    2003-06-01

    Congruent cut surfaces are a predisposition for good apposition of donor and recipient during penetrating keratoplasty (PK). The purpose of this study was to assess the impact of the intracameral pressure during nonmechanical donor trephination from the epithelial side on the cut angles for experimental human PK. With a Q-switched 2.94 micro m Er : YAG laser a 6 mm sized corneal donor trephination was performed subtotally in 30 human corneas using an artificial anterior chamber device allowing different intracameral pressures (10, 20, and 40 mm Hg). The cut angles were measured immediately after the trephination by ultrasound biomicroscopy (UBM) at four quadrants: between trephination cut and corneal epithelium (angle 1 = A1-UBM) and between trephination cut and horizontal plane (angle 2 = A2-UBM). The positions of the measures were marked, the corneas were fixed in a buffered 10 % paraformaldehyde solution, and the same positions were analyzed by histology. The histological cuts were digitized, the images printed, and the cut angles measured in paper (A1-histology). Mean angles were 111.6 degrees /113.5 degrees /126.6 degrees (A1-UBM), 88.4 degrees /93.5 degrees /101.8 degrees (A2-UBM) and 120.4 degrees /125.1 degrees /119.3 degrees (A1-histology) with 10/20/40 mm Hg, respectively. The A2-UBM showed a significant increase of divergence with increasing intracameral pressure (p < 0.03). For A1-UBM cut angles with 10 and 20 mm Hg were significantly smaller compared to those with 40 mm Hg (p < 0.002), but there was no difference of divergence between 10 and 20 mm Hg. The A1-histology cut angle showed no correlation with intracameral pressure (p > 0.09). Increasing intracameral pressure using an artificial anterior chamber during donor trephination from the epithelial side for nonmechanical PK using Er : YAG laser results in increasing divergence of cut angles. This may disturb the congruence of the cut angles in donor-recipient apposition. To achieve standardised cut

  20. [Long-term outcome after penetrating keratoplasty for keratoconus--impact of preoperative corneal curvature and best corrected visual acuity on the functional results].

    PubMed

    Preclik, A; Langenbucher, A; Seitz, B; Cursiefen, C

    2010-03-01

    The purpose of this study was to assess the long-term functional visual results of penetrating keratoplasty for keratoconus and to assess the impact of the patient's preoperative corneal curvature and preoperative best spectacle corrected visual acuity (BCVA) on the refractive outcome. In this retrospective study 456 patients with keratoconus who received central round penetrating keratoplasty (PK) were examined 1/3/5/8/ > 9 years postoperatively. Patients were divided retrospectively into subgroups: first based on their preoperative keratometric (K-) readings: group I.1, < 50 diopters (D) (n = 21); group I.2, 50 - 60 D (n = 102); group I.3, > or = 60 D (n = 164); group I.4, irregular corneal shape with non-measurable K-reading (n = 158), group I.0 unknown preoperative K-reading (n = 58) and then based on the preoperative BCVA: group II.0 BCVA < or = 0.1 (n = 204); group II.1 BCVA > 0.1 (n = 263). The trephination was performed using the 193-nm excimer laser and the transplanted cornea was fixed by a double running cross-stitch suture. The outcome measures included keratometric central refractive equivalent (KEQ), keratometric astigmatism (AST), spherical equivalent (SEQ), refractive cylinder (CYL), best corrected visual acuity (BCVA), surface regularity index (SRI), surface asymmetry index (SAI)topographic central power equivalent (T-EQ) and topographic astigmatism (T-AST). Five/eight years postoperatively, BCVA was 0.71/0.73; KEQ was 43.4/44.4 D; SEQ -1.6/-0.8; AST was 3.4/3.6 D; CYL was 3.0/3.0 D, SRI was 0.88/0.83; SAI was 0.78 / 0.78; T-EQ was 44.5/44.9 D and T-AST was 4.0/4.2 D. The results for BCVA of patients whose preoperative BCVA measured < or = 0.1 were significantly worse than the results of patients with better preoperative BCVA. Other comparisons among the subgroups revealed no further significant differences for any parameter tested. In our study the long-term results of BCVA after penetrating keratoplasty for keratoconus seem to be quite stable (0

  1. Effects of corneal irregular astigmatism on visual acuity after conventional and femtosecond laser-assisted Descemet's stripping automated endothelial keratoplasty.

    PubMed

    Tomida, Daisuke; Yamaguchi, Takefumi; Ogawa, Akiko; Hirayama, Yumiko; Shimazaki-Den, Seika; Satake, Yoshiyuki; Shimazaki, Jun

    2015-07-01

    To compare short-term outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) using a graft prepared with either a femtosecond laser or a microkeratome. Thirty-eight patients underwent DSAEK with grafts prepared with either a femtosecond laser (f-DSAEK; 21 eyes) or a microkeratome (m-DSAEK; 17 eyes). Visual acuity, endothelial cell density, regular astigmatism and irregular astigmatism were compared between the two groups preoperatively and at 1, 3, and 6 months post-operatively. Fourier analysis was conducted to calculate astigmatism of the anterior and posterior surfaces, and total cornea, using anterior segment optical coherence tomography (AS-OCT). Visual acuity (logMAR) improved from 1.20 ± 0.60 to 0.43 ± 0.25 after m-DSAEK (P < 0.001) and from 1.20 ± 0.57 to 0.77 ± 0.33 after f-DSAEK (P = 0.0028) at 6 months following DSAEK. Visual acuity after m-DSAEK was significantly better than after f-DSAEK at 1, 3, and 6 months (P < 0.05). AS-OCT corneal images revealed greater irregularities on the posterior surfaces of f-DSAEK grafts compared to m-DSAEK grafts. Irregular astigmatism of the total cornea and the posterior surface was significantly larger after f-DSAEK than after m-DSAEK, although there was no significant difference in irregular astigmatism of the anterior surface at 6 months. Postoperative visual acuity was significantly correlated with the postoperative irregular astigmatism of the total cornea (r = 0.6657 and P < 0.001) and the anterior (r = 0.416, P = 0.016) and posterior surfaces (r = 0.7046, P < 0.001). Visual outcomes after f-DSAEK were poor compared to conventional m-DSAEK due to an increase in irregular astigmatism caused by posterior surface irregularities.

  2. Lamellar Keratoplasty: A Literature Review

    PubMed Central

    Espandar, Ladan; Carlson, Alan N.

    2013-01-01

    The concept of lamellar keratoplasty (LK) is not new. However, newer forms of lamellar keratoplasty techniques have emerged in the last decade or so revolving around the concept of targeted replacement of diseased corneal layers. These include anterior lamellar keratoplasty (ALK) techniques that aim to selectively replace diseased corneal stroma and endothelial keratoplasty techniques aiming to replaced damaged endothelium in endothelial disorders. Recent improvements in surgical instruments and introduction of new techniques as well as inherent advantages such as preservation of globe integrity and decreased graft rejection have resulted in the reintroduction of LK as an acceptable alternative to conventional PK. In this review, indications, benefits, limitations, and outcomes of various anterior and posterior lamellar keratoplasty techniques are discussed. PMID:24223301

  3. Lamellar keratoplasty: a literature review.

    PubMed

    Espandar, Ladan; Carlson, Alan N

    2013-01-01

    The concept of lamellar keratoplasty (LK) is not new. However, newer forms of lamellar keratoplasty techniques have emerged in the last decade or so revolving around the concept of targeted replacement of diseased corneal layers. These include anterior lamellar keratoplasty (ALK) techniques that aim to selectively replace diseased corneal stroma and endothelial keratoplasty techniques aiming to replaced damaged endothelium in endothelial disorders. Recent improvements in surgical instruments and introduction of new techniques as well as inherent advantages such as preservation of globe integrity and decreased graft rejection have resulted in the reintroduction of LK as an acceptable alternative to conventional PK. In this review, indications, benefits, limitations, and outcomes of various anterior and posterior lamellar keratoplasty techniques are discussed.

  4. Mushroom keratoplasty in pediatric patients☆

    PubMed Central

    Busin, Massimo; Beltz, Jacqueline; Scorcia, Vincenzo

    2011-01-01

    Objective To report the outcome of mushroom keratoplasty for the treatment of full thickness corneal disease in pediatric patients with healthy endothelium. Methods A retrospective analysis of pediatric patients who underwent mushroom keratoplasty. The medical records of pediatric patients suffering from full thickness corneal stromal disease with normal endothelium who underwent mushroom keratoplasty at our Institution were included. A two-piece donor graft consisting of a large anterior stromal lamella (9.0 mm in diameter and ±250 μm in thickness) and a small posterior lamella (5–6.5 mm in diameter) including deep stroma and endothelium, prepared with the aid of a microkeratome had been transplanted in all cases. Ophthalmic examination including slit lamp examination, best corrected visual acuity, and corneal topography was performed preoperatively and at each postoperative visit on all patients. The endothelial cells were assessed by specular microscopy in these patients. Results Six eyes of six patients (five males and one female) were included. The mean age was 9.3 years (range 5–15 years). Average follow-up was 17.8 months (range 9–48 months). There were no early or late complications recorded. All corneas were clear at the last follow up visit. Preoperative best corrected visual acuity (BCVA) was worse than 20/70 in all six eyes. Postoperatively, four eyes achieved BCVA of 20/40 or better. Endothelial cell loss (n eyes = 3 averaged 24% (range 19–31%). The mean endothelial cell loss was 24% (range 19–31%) among these patients. Conclusions Microkeratome assisted mushroom keratoplasty is a viable surgical option for pediatric eyes with full thickness corneal stromal disease and healthy endothelium. Mushroom keratoplasty combines the refractive advantage of a large penetrating keratoplasty with the survival advantage of a small penetrating keratoplasty. Furthermore, mushroom keratoplasty exhibits the mechanical advantage of a shaped

  5. iTRAQ-Based Quantitative Proteomic Analysis of Tear Fluid in a Rat Penetrating Keratoplasty Model With Acute Corneal Allograft Rejection.

    PubMed

    Huang, Feifei; Xu, Jianjiang; Jin, Hong; Tan, Jianwen; Zhang, Chaoran

    2015-06-01

    This study aimed to develop a greater understanding of the mechanisms underlying acute corneal allograft rejection by identifying differentially expressed tear proteins at defined stages and discovering potentially important proteins involved in the process. The isobaric tags for relative and absolute quantitation (iTRAQ)-two-dimensional liquid chromatography-tandem mass spectrometry (2DLC-MS/MS) technique was used to identify tear proteins showing significant alterations in a rat penetrating keratoplasty model at different time points. Bioinformatics technology was applied to analyze the significant proteins, and a potential protein was verified by Western blotting. A total of 269 proteins were quantified, and 118 proteins were considered to be significantly altered by at least 2.0- or 0.5-fold. For gene ontology annotations, the top enrichments were neurological disease, free radical scavenging, cell death and survival, and cell movement. For pathway analyses, the top enrichments were LXR/RXR activation, acute phase response signaling, clathrin-mediated endocytosis signaling, and coagulation system. Coronin-1A was verified as a potential protein involved in the early stage of acute corneal allograft rejection. This study first demonstrates that tear proteomics is a powerful tool for better understanding of the mechanisms underlying acute corneal rejection, and that coronin-1A in tears might be closely related to allograft rejection.

  6. Deep lamellar keratoplasty by deep parenchyma detachment from the corneal limbs

    PubMed Central

    Senoo, T; Chiba, K; Terada, O; Mori, J; Kusama, M; Hasegawa, K; Obara, Y

    2005-01-01

    Aim: To improve the deep lamellar keratoplasty technique. Method: For the easy and reliable perfomance of deep lamellar keratoplasty (DLKP), detachment of Descemet’s membrane through the corneal limber flap was improved. To expose Descemet’s membrane, the parenchyma was detached by hydrodelamination through a sclerocorneal flap made in the corneal limbs. The parenchyma was removed after the pseudochamber between it and Descemet’s membrane was maintained with viscoelastic material. The corneal graft was placed with a running suture. 22 eyes were treated. Results: Complete exposure of Descemet’s membrane was obtained in 20 of the 22 eyes (91%). The membrane was perforated in five of the 22 eyes (23%) during surgery, and two of the 22 eyes (9%) were converted to penetrating keratoplasty. These two eyes developed keratoconus after acute corneal hydrops. Conclusion: Compared with the conventional procedure, this new method provides easy, reliable exposure of Descemet’s membrane. PMID:16299139

  7. Effects of Cataract Surgery on Endothelium in Transplanted Corneal Grafts: Comparison of Extracapsular Cataract Extraction and Phacoemulsification for Complicated Cataract after Penetrating Keratoplasty

    PubMed Central

    Zhou, Hong-Wei; Xie, Li-Xin

    2016-01-01

    Background: The endothelium should be carefully evaluated when choosing a surgical technique for cataract removal. Therefore, we aimed to study the effects of different cataract surgery techniques on endothelial cell loss in transplanted corneal grafts. Methods: A total of 54 patients who received complicated cataract surgery in post-penetrating keratoplasty (PKP) eyes at the Shandong Eye Institute between February 2001 and June 2014 were included, and clinical records were reviewed. Baseline demographic details, clinical characteristics, endothelial cell density (ECD), and best-corrected visual acuity (BCVA) were recorded. Wilcoxon rank-sum test and Wilcoxon signed-rank test were used to test the equality of medians. A regression model was constructed to compare the reduced rate of ECD. Results: Of the 54 eyes included in this study, extracapsular cataract extraction (ECCE) was performed in 34 eyes of 33 patients (ECCE group) whereas phacoemulsification was performed in 20 eyes of 20 patients (phacoemulsification group). There was no significant difference in the median age (P = 0.081) or preoperative ECD (P = 0.585) between the two groups. At 6 months after cataract surgery, ECD in ECCE group was significantly higher than that in phacoemulsification group (P = 0.043). In addition, the endothelial cell loss rate in ECCE group was significantly lower than that in phacoemulsification group at 2 months (P = 0.018), 4 months (P < 0.001), and 6 months (P < 0.001) after cataract surgery. Endothelial cell loss rate after cataract surgery increased over the 6-month study duration in both ECCE group (P < 0.001) and phacoemulsification group (P < 0.001), but phacoemulsification resulted in a greater reduction in ECD than that of ECCE in transplanted corneal grafts (P < 0.001). There was no significant difference in postoperative BCVA between the two groups (P = 0.065). Conclusion: ECCE is more suitable than phacoemulsification in cataract surgery in complicated cataract

  8. Effects of Cataract Surgery on Endothelium in Transplanted Corneal Grafts: Comparison of Extracapsular Cataract Extraction and Phacoemulsification for Complicated Cataract after Penetrating Keratoplasty.

    PubMed

    Zhou, Hong-Wei; Xie, Li-Xin

    2016-09-05

    The endothelium should be carefully evaluated when choosing a surgical technique for cataract removal. Therefore, we aimed to study the effects of different cataract surgery techniques on endothelial cell loss in transplanted corneal grafts. A total of 54 patients who received complicated cataract surgery in post-penetrating keratoplasty (PKP) eyes at the Shandong Eye Institute between February 2001 and June 2014 were included, and clinical records were reviewed. Baseline demographic details, clinical characteristics, endothelial cell density (ECD), and best-corrected visual acuity (BCVA) were recorded. Wilcoxon rank-sum test and Wilcoxon signed-rank test were used to test the equality of medians. A regression model was constructed to compare the reduced rate of ECD. Of the 54 eyes included in this study, extracapsular cataract extraction (ECCE) was performed in 34 eyes of 33 patients (ECCE group) whereas phacoemulsification was performed in 20 eyes of 20 patients (phacoemulsification group). There was no significant difference in the median age (P = 0.081) or preoperative ECD (P = 0.585) between the two groups. At 6 months after cataract surgery, ECD in ECCE group was significantly higher than that in phacoemulsification group (P = 0.043). In addition, the endothelial cell loss rate in ECCE group was significantly lower than that in phacoemulsification group at 2 months (P = 0.018), 4 months (P < 0.001), and 6 months (P < 0.001) after cataract surgery. Endothelial cell loss rate after cataract surgery increased over the 6-month study duration in both ECCE group (P < 0.001) and phacoemulsification group (P < 0.001), but phacoemulsification resulted in a greater reduction in ECD than that of ECCE in transplanted corneal grafts (P < 0.001). There was no significant difference in postoperative BCVA between the two groups (P = 0.065). ECCE is more suitable than phacoemulsification in cataract surgery in complicated cataract after PKP.

  9. Q-switched erbium:YAG laser corneal trephination: thermal damage in corneal stroma and cut regularity of nonmechanical Q-switched erbium:YAG laser corneal trephination for penetrating keratoplasty.

    PubMed

    Stojkovic, M; Seitz, B; Langenbucher, A; Viestenz, A; Viestenz, A; Hofmann-Rummelt, C; Schlötzer-Schrehardt, U; Küchle, M; Naumann, G O H

    2004-01-01

    To assess stromal thermal damage and cut regularity induced by nonmechanical Q-switched Er:YAG laser corneal trephination for penetrating keratoplasty. Corneal trephination was performed in 80 enucleated porcine eyes by Q-switched (2.94-microm) Er:YAG laser, along with donor and recipient masks made of metal or ceramic. All combinations of 0.65- or 0.96-mm spot diameter and 45- or 50-mJ/pulse energy setting were used with each of the masks at a 5-Hz repetition rate. Corneas were processed for histologic examinations. Stromal thermal damage was quantified on PAS-stained slides, and cut regularity was assessed semiquantitatively on a scale from 0 (regular) to 3 (highly irregular). Transmission electron microscopy and scanning electron microscopy were performed on selected specimens. The least thermal damage (mean +/- SD = 6.2 +/- 0.7 microm) was found in the donor ceramic group with 50-mJ/pulse energy and 0.65-mm spot diameter, while the best regularity of the cut (1.2 +/- 0.4) was found in the donor ceramic group with 45-mJ pulse energy and 0.65-mm spot diameter. Thermal damage was less pronounced in donor than in recipient corneas (P < 0.01). Smaller spot diameter (0.65 mm) led to less thermal damage (P < 0.01) than the use of a 0.96-mm spot diameter. The differences in thermal damage between ceramic and metal masks were minimal. After Q-switched Er:YAG laser corneal trephination for nonmechanical penetrating keratoplasty, reproducible high cut regularity and low concomitant thermal damage were observed. This is an encouraging finding in the search for a nonmechanical trephine for penetrating keratoplasty combining high precision and low cost.

  10. Q-Switched 2.94-microm Er:YAG laser trephination with convergent and divergent cut angles for penetrating keratoplasty.

    PubMed

    De Souza, Renate Ferreira; Seitz, Berthold; Langenbucher, Achim; Hofmann-Rummelt, Carmen; Schlötzer-Schrehardt, Ursula; Viestenz, Anja; Küchle, Michael; Naumann, Gottfried O H

    2003-08-01

    To study the morphologic properties of perpendicular (P), convergent (C), and divergent (D) cut angles using different speeds of rotations during donor and recipient nonmechanical trephination for experimental penetrating keratoplasty. With a Q-switched 2.94-microm Er:YAG laser corneal trephination was performed in 150 enucleated porcine eyes using ceramic open masks with 8 "orientation teeth/notches" and an automated globe rotation device allowing different cut angles [0 degree (P), 10 and 20 degrees (C and D)] toward the optical axis and variation of the rotation speed [3, 7, and 11 rotations per minute (rpm)]. The regularity of the cut (I, regular; II, slightly irregular; III, irregular) was assessed by light microscopy. The area of thermal damage and the number and size of "spikes" in the stroma at the superficial, intermediate and deep level of the excision were analyzed using digital images and the Optimas image processing software. The regularity of the cut was classified as I in 42%/22% of donor/recipient and as II in 41%/56%, respectively. The thermal damage was least expressed with D20 degree cut angle and donor mask (P < 0.01). With all cut angles and speeds of rotation, thermal damage at the deep level of excision was significantly smaller (P < 0.01). With different speeds of donor rotations, the thermal damage showed no significant difference. With recipient trephination, the thermal damage at the deep level was greatest with 7 rpm (P < 0.01). The number and size of spikes of thermal damage with donor and recipient masks were significantly smaller in the deep stroma (P < 0.01). Q-switched Er:YAG laser trephination with appropriate settings results in low thermal damage zones at the cut margin. Different cut angles and speeds of trephination may affect the cut performance and quality of the excision. In our study, low rotation speed and divergent donor cut angles showed the best results. The cut quality and the small thermal damage with the Q-switched 2

  11. Pseudomonas aeruginosa Endophthalmitis after Penetrating Keratoplasty Transmitted from the Same Donor to Two Recipients Confirmed by Pulsed-Field Gel Electrophoresis ▿

    PubMed Central

    Oguido, Ana Paula Miyagusko Taba; Casella, Antonio Marcelo Barbante; Hofling-Lima, Ana Luisa; Pacheco, Sergio Arruda; Bispo, Paulo José Martins; Marques, Fernanda

    2011-01-01

    Two devastating cases of multidrug-resistant Pseudomonas aeruginosa endophthalmitis after keratoplasty as the result of transmission from the same donor were confirmed by pulsed-field gel electrophoresis. Strategies for preventing donor-to-host transmission, such as the use of antimicrobial agents of greater efficacy and better methods for detecting microorganisms in preservation medium, could minimize this type of transmission. PMID:21775545

  12. Measuring skin penetration by confocal Raman microscopy (CRM): correlation to results from conventional experiments

    NASA Astrophysics Data System (ADS)

    Lunter, Dominique; Daniels, Rolf

    2016-03-01

    Confocal Raman microscopy has become an advancing technique in the characterization of drug transport into the skin. In this study the skin penetration of a local anesthetic from a semisolid preparation was investigated. Furthermore, the effect of the chemical enhancers propylene glycol and POE-23-lauryl ether on its penetration was investigated. The results show that confocal Raman microscopy may provide detailed information on the penetration of APIs into the skin and may elucidate their distribution within the skin with high resolution. The results of the CRM analysis are fully in line with those of conventional permeation and penetration experiments.

  13. [Keratoplasty in Children and Adolescents].

    PubMed

    Lang, S J; Richter, C; Richter, O; Böhringer, D; Geerling, G; Reinhard, T

    2017-02-13

    Background The conditions for long-term graft survival in infants and children are unfavorable, due to the different immunological features, the impaired clinical examination and the reduced compliance and treatment adherence. However, penetrating keratoplasty is often the only option to prevent amblyopia and there may be no alternative. We examined the different indications, graft survival and complications in two specialised centres. Material and Methods We identified all patients who were under the age of 18 years at the time of their penetrating keratoplasty. We then assessed the electronic file on indications, graft failure, visual acuity, enucleation and further complications. Results A total of 104 eyes of 95 patients (54 % female) were identified. Median age at the time of surgery was 14 years (quartiles 8 and 16 years). Median follow-up was 2.7 years. The following indications were identified: keratoconus (39 %), penetrating injury (18 %), non-herpetic corneal scars (12 %), herpetic corneal scars (6 %), sclerocornea (3 %), chemical burn (3 %) and miscellaneous indications (19 %). Clear graft survival according to the Kaplan-Meier method ranged from 100 % (keratoconus) to 35 % (sclerocornea). Enucleation was only necessary in patients with penetrating injuries (n = 2). Kaplan-Meier analysis estimated the failure of all grafts after one year in infants. In older patients, 90 % of grafts were still clear at that time. Conclusion Prognosis of penetrating keratoplasty in children is related to the indication, and therefore the underlying disease, as well as the patients' age. In particular, infants exhibited poor prognosis, with only a very short period of clear graft survival. In indications, keratoconus showed the best prognosis, whereas sclerocornea and penetrating injuries had the worst prognosis.

  14. Canopy penetration and deposition of barrier sprays from electrostatic and conventional sprayers

    USDA-ARS?s Scientific Manuscript database

    An experimental study was conducted to investigate the effectiveness of barrier sprays from electrostatic and conventional sprayers through measurement of penetration into and deposition on to natural vegetation. Two conventional and three electrostatic sprayers were used in the study. One sprayer...

  15. [Development of Endothelial Cell Density after Penetrating Keratoplasty in Patients with Fuchs Dystrophy or Keratoconus - Comparison of Excimer Laser and Mechanical Trephination].

    PubMed

    Schumacher, M; Langenbucher, A; Seitz, B

    2017-05-01

    Purpose The aim of this retrospective study was to compare the development of endothelial cell density (ECD) after penetrating keratoplasty (PKP) in patients with Fuchs dystrophy (FD), keratoconus (KC) or "other diagnoses" (OD), depending on the type of trephination. Patients and Methods In 104 eyes with Fuchs dystrophy, keratoconus or "other diagnoses", the ECD after PKP using either excimer laser (EXC) or mechanical trephination (MECH) was registered after 1.5, 6, 12, 18 and 24 months. With linear and exponential regression models, the endothelial cell loss (ECL) was determined as absolute and percentage cell loss per year. Results For the entire group of patients, ECD was significantly higher after EXC-PKP during the full range of follow-up (except 6 months). With a linear regression model, there was no significant difference in the absolute ECL per year (p = 0.084), but with an exponential regression model, there was a significant difference in the percentage ECL per year (p = 0.021) in favour of EXC trephination. For keratoconus (n = 33), except for the 24-month-follow-up (p = 0.035), ECD was not significantly different on the basis of EXC vs. MECH. With a linear regression model, there was a significant difference in the absolute ECL per year (p = 0.015) in favour of EXC-trephination, but with an exponential regression model there was no significant difference in the percentage ECL per year (p = 0.088) between the two types of threphination. In patients with FUCHS (n = 35) - except for the 6-week-follow-up (p = 0.024) - ECD was not significantly different for EXC vs. MECH. With linear/exponential regression model, the ECL per year was not significantly different in favour of any type of trephination (p = 0.287/p = 0.121). In patients with OD (n = 36), ECD was not significantly different for EXC vs. MECH. With a linear/exponential regression model, the ECL per year was not significantly different in favour of any

  16. Comparison of the Penetration Depth of Conventional and Nano-Particle Calcium Hydroxide into Dentinal Tubules.

    PubMed

    Zand, Vahid; Mokhtari, Hadi; Hasani, Aila; Jabbari, Golchin

    2017-01-01

    The aim of this in vitro study was to evaluate and compare the penetration depth of conventional (CH) and nano-particle calcium hydroxide (NCH) into dentinal tubules. Ninety human single-rooted teeth were instrumented by RaCe rotary system and after chemomechanical preparation were randomly divided in two equal groups (n=45). In the first group conventional CH and in the other NCH was used as intracanal medicament. After 2 weeks of incubation all roots were intentionally split at longitudinal axis and prepared for scanning electron microscope (SEM) observation. Three zones of each root, coronal, middle and apical were examined under SEM and the maximum penetration depth of the dressing material into dentinal tubules was recorded for each zone. Data were analyzed using the independent sample t test and the level of significance was set at 0.05. In all of the three zones, NCH group had greater penetration depth than CH (P<0.001). In both groups the penetration depth increased from the apical section to the coronal. The depth of penetration of nano-particle calcium hydroxide into the dentinal tubules was significantly higher than that of conventional calcium hydroxide. The lowest penetration depth was observed in apical zone in both groups.

  17. [Assessment of measured respirable dust sampler penetration and the sampling convention for work environment measurement].

    PubMed

    Myojo, Toshihiko

    2005-11-01

    The relationship between dust size and penetration for a static horizontal elutriator (Sibata C-30) was measured in calm air. The elutriator as a low-volume air sampler is widely used as a dust size classifier in work environment measurements. The actual penetrations were compared with the theoretical models of the sampler and with sampling convention for respirable dust in work environment measurement. The sampling convention was recently introduced into the Japanese standard for work environment measurement and is based on the ISO 7708 respirable dust convention. The bias of sampled masses from the respirable dust was calculated for two flow rates of the sampler, i.e., 50% cut sizes of 4 microm and 5 microm, from measured penetration curves. The bias of the sampler was overestimated in the 5 microm, 50% cut condition and underestimated in the 4 microm, 50% cut condition for most workplace sampling situations.

  18. Outcomes of keratoplasty in the mucopolysaccharidoses: an international perspective.

    PubMed

    Ohden, Kaitlyn L; Pitz, Susanne; Ashworth, Jane; Magalhães, Augusto; Marinho, Diane R; Lindahl, Päivi; Teär Fahnehjelm, Kristina; Summers, C Gail

    2017-07-01

    To describe visual outcomes after penetrating keratoplasty and deep anterior lamellar keratoplasty in patients with mucopolysaccharidoses. This is a retrospective review of keratoplasty in consecutive patients from Brazil, England, Finland, Germany, Portugal, Sweden and the USA. All patients had corneal clouding due to mucopolysaccharidoses. Preoperative and postoperative visual outcome and ocular comorbidities were identified. Success was arbitrarily defined as any improvement in visual acuity or best-corrected visual acuity better than logarithm of the minimum angle of resolution 0.30 (20/40). Statistical analysis included only data from first operated eyes in the 16 patients who underwent bilateral keratoplasty. Forty-eight eyes from 32 patients with mucopolysaccharidoses I, IV or VI are reported. Mean follow-up was 70 months (range: 5-186). Penetrating keratoplasty was performed in 45 eyes and deep anterior lamellar keratoplasty in 3 eyes. At last follow-up, a successful visual outcome for penetrating keratoplasty in first operated/only operated eyes was found in 63%. Rejection episodes occurred in 23% of grafts; however, a clear graft was recorded at last follow-up in 94%. Ocular pathway comorbidities were identified in 63% of eyes transplanted. Clear corneal grafts can be obtained for patients with corneal clouding due to mucopolysaccharidosis with improvement in visual acuity in the majority. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  19. Canopy penetration and deposition of barrier sprays from electrostatic and conventional sprayers.

    PubMed

    Hoffmann, W C; Farooq, M; Walker, T W; Fritz, B; Szumlas, D; Quinn, B; Bernier, U; Hogsette, J; Lan, Y; Huang, Y; Smith, V L; Robinson, C A

    2009-09-01

    An experimental study was conducted to investigate the usefulness of electrostatic and conventional sprayers for barrier applications. Two conventional and three electrostatic sprayers were used in the study. Usefulness of the sprayers was rated based on penetration of spray into and deposition onto 2 sides of leaves on natural vegetation. Bifenthrin (Talstar adulticide) was applied at labeled rate, fluorescent dye was added to the tank mix as tracer, and all sprayers applied the dye and insecticide at the same rate. The results indicated that sprayers producing larger droplets produced significantly higher deposition on vegetation in barrier applications than the sprayers producing smaller droplets. Sprayers with higher air velocity at the nozzle discharge proved significantly better for barrier sprays than the sprayers with lower air velocity. Electrostatic sprayers did not show any improvement in deposition on vegetation or in penetration into vegetation over the conventional sprayers. There was no difference in deposition between truck-mounted and backpack sprayers.

  20. The corneal endothelium after keratoplasty for keratoconus.

    PubMed

    Jonuscheit, Sven; Doughty, Michael J; Ramaesh, Kanna

    2013-03-01

    The aim was to assess the corneal endothelium, post-operative visual outcome and complications following keratoplasty for keratoconus. Seventy-six corneal grafts (57 per cent penetrating keratoplasties and 43 per cent deep anterior lamellar keratoplasties) were assessed as part of routine follow-up at the Ophthalmology Department at Gartnavel General Hospital in Glasgow. Routine ophthalmic assessment included visual acuity, slitlamp biomicroscopy and scanning slit confocal microscopy of the central cornea. Case records were reviewed and demographic, surgical and post-operative data retrieved. Linear and logistic regression models were used to determine associations between endothelial cell density, visual acuity and post-operative complications. Kaplan-Meier analysis was used to estimate the probability for grafts to retain more than 700 endothelial cells per mm(2) and to have 0.3 logMAR or better vision. Odds ratios were calculated to assess the risk for low cell counts and poor visual outcome. The mean and standard deviation of the endothelial cell count was predictably higher in lamellar (2033 ± 643 cells per mm(2)) than penetrating keratoplasties (898 ± 380 cells per mm(2)) and the mean post-operative cell count for grafts without post-operative complications was higher (1585 ± 775) than those with complications (1312 ± 747 cells per mm(2)). Mean visual acuity was 0.25 ± 0.20 and 0.29 ± 0.41 for lamellar and penetrating keratoplasties, respectively. A higher number of post-operative events was associated with an increased risk for graft rejection (odds ratio 2.40, p = 0.008, multiple logistic regression) and with poorer visual outcome (odds ratio 1.38, p = 0.044). After keratoplasty, the visual outcome and endothelial cell density were not associated, either in penetrating or deep anterior lamellar grafts (p > 0.05). In keratoplasties performed for keratoconus, visual outcome cannot be predicted reliably by post-operative endothelial cell density but post

  1. Combined intrastromal astigmatic keratotomy and laser in situ keratomileusis flap followed by photoablation to correct post-penetrating keratoplasty ametropia and high astigmatism: One-year follow-up.

    PubMed

    Shalash, Riad B; Elshazly, Malak I; Salama, Marwa M

    2015-10-01

    To evaluate a new technique combining intrastromal astigmatic keratotomy (AK) with a laser in situ keratomileusis (LASIK) flap followed by excimer laser photoablation to correct post-penetrating keratoplasty (PKP) high astigmatism and ametropia. Kasr El Aini Hospital, Cairo University, Cairo, Egypt. Prospective interventional uncontrolled case series. Patients with post-PKP high astigmatism and ametropia had paired intrastromal AK with LASIK flap using the M2 microkeratome followed 2 to 3 months later by excimer laser photoablation. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), mean refractive spherical equivalent (SE), and mean cylinder after each step and at the 1-year follow-up. The study comprised 20 eyes (20 patients). All parameters were significantly improved in all patients by the last follow-up visit. The mean UDVA improved from 1.07 logMAR ± 0.2 (SD) preoperatively to 0.23 ± 0.18 logMAR (P < .001), the mean CDVA improved from 0.79 ± 0.18 logMAR to 0.12 ± 0.12 logMAR (P < .001), the mean refractive SE improved from -5.04 ± 2.62 diopters (D) to -1.47 ± 1.32 D (P = .001), and the mean cylinder reduced from -5.39 ± 0.98 D to -1.05 ± 0.71 D (P < .001). The mean correction index was 0.84 ± 0.10, and the mean flattening index was 0.83 ± 0.10. Thirty-five percent of cases developed microperforations, and 15% developed epithelial ingrowth. This combined approach allowed for the correction of high astigmatism and ametropia following PKP; however, epithelial ingrowth requiring intervention is a complication to be considered. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  2. Conventional and synthetic aperture processing for airborne ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Cameron, Robert M.; Simkins, William L.; Brown, Russell D.

    1994-07-01

    For the past four years Airborne Environmental Surveys, a division of Era Aviation, Inc., has used unique and patented airborne frequency modulated, continuous wave radars and processes for detection and mapping subsurface phenomena. Primary application has focused on the detection of manmade objects in landfills, hazardous waste sites (some of which contain unexploded ordnance), and subsurface plumes of refined free- floating hydrocarbons. Recently, MSB Technologies, Inc. has developed a form of synthetic aperture radar processing, called GPSAR, that is tailored especially for the AES radars. Used as an adjunct to more conventional airborne ground-penetrating radar data processing techniques, GPSAR takes advantage of the radars' coherent transmission and produces imagery that is better focused and more accurate in determining an object's range and true depth. This paper describes the iterative stages of data processing and analysis used with the radars and shows the added advantages that GPSAR processing offers.

  3. Current techniques of lamellar keratoplasty for keratoconus

    PubMed Central

    Spadea, Leopoldo; Rosa, Victoria De

    2016-01-01

    In recent years, there has been a considerable interest regarding the concept of lamellar keratoplasty (LK), which contributed in spreading the use of this procedure in the treatment of keratoconus. This is a new frontier in corneal surgery that minimizes trauma on the recipient patient since it works on a “closed bulb”. The LK surgery, in fact, aims to selectively replace diseased corneal stroma, leaving the healthy endothelium. The main advantage of LK is to avoid major causes of failure of penetrating keratoplasty as immunological rejection, and the late mismatch in the transplanted cornea, thus increasing the life of transplantation. In the last decade, several techniques of LK have been proposed, depending on how the anterior portion of the recipient cornea is removed. This article, through a literary research reviews the various emerging techniques of anterior lamellar surgery for the management of keratoconus, analyzing their indications, visual outcomes, and rate of complications. PMID:26837393

  4. Comparison of sealer penetration using the EndoVac irrigation system and conventional needle root canal irrigation.

    PubMed

    Kara Tuncer, Aysun; Unal, Bayram

    2014-05-01

    The aim of this study was to compare the effect of the EndoVac irrigation system (SybronEndo, Orange, CA) and conventional endodontic needle irrigation on sealer penetration into dentinal tubules. Forty single-rooted, recently extracted human maxillary central incisors were randomly divided into 2 groups according to the irrigation technique used: conventional endodontic needle irrigation and EndoVac irrigation. All teeth were instrumented using the ProFile rotary system (Dentsply Maillefer, Ballaigues, Switzerland) and obturated with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) labeled with fluorescent dye. Transverse sections at 1, 3, and 5 mm from the root apex were examined using confocal laser scanning microscopy. The total percentage and maximum depth of sealer penetration were then measured. Mann-Whitney test results showed that EndoVac irrigation resulted in a significantly higher percentage of sealer penetration than conventional irrigation at both the 1- and 3-mm levels (P < .05). However, no difference was found at the 5-mm level. The 5-mm sections in each group showed a significantly higher percentage and maximum depth of sealer penetration than did the 1- and 3-mm sections (P < .05). The EndoVac irrigation system significantly improved the sealer penetration at the 1- to 3-mm level over that of conventional endodontic needle irrigation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Conductive keratoplasty: histological study of human corneas.

    PubMed

    Naoumidi, Tatiana L; Pallikaris, Ioannis G; Naoumidi, Irini I; Astyrakakis, Nikolaos I

    2005-12-01

    To determine the morphologic changes in human corneas over time following radiofrequency-based conductive keratoplasty (CK) treatment. Prospective, observational case series. In a single-center study six human corneas of six patients with localized peripheral keratoconus underwent CK treatment followed by penetrating keratoplasty. Three spots were applied in the periphery of each cornea (6 mm optical zone). Corneal buttons were examined with light and electron microscopy at different postoperative intervals up to 6 months post-CK. In samples assessed on day one post-CK, small areas of detachment between the basal layer of epithelial cells and Bowman's layer were observed. At 1 week after the CK procedure, the epithelium appeared almost normal. Endothelium and Descemet's membrane had no alterations. In all samples, thermally induced misconfiguration of collagen fibers, described as "crumpled" changes of collagen layers, was observed reaching 75% to 80% of the stromal depth. The area of alterations had a cylindrical shape with a diameter of 120 mum. The conductive keratoplasty procedure produced collagen "crumpling and splitting" changes in human corneas, which were observed during the follow-up of 6 months. Areas adjacent to treatment site were minimally damaged.

  6. [Perspectives of excimer laser-assisted keratoplasty].

    PubMed

    Seitz, B; Langenbucher, A; Naumann, G O H

    2011-09-01

    The purpose of this paper is to demonstrate the evolution of laser keratoplasty and to outline the potential future perspectives of this technique. For non-contact donor trephination from the epithelial side an artificial anterior chamber has been used. Since 1989 more than 3,300 penetrating keratoplasty operations (PKP) have been performed successfully with the Zeiss-Meditec MEL60® excimer laser in Erlangen and Homburg/Saar. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient decentration, reduces vertical tilt and horizontal torsion of the graft in the recipient bed, thus resulting in significantly less all-sutures-out keratometric astigmatism, higher regularity of the topography and better visual acuity. Besides less blood-aqueous barrier breakdown during the early postoperative course after PKP, excimer laser trephination does not induce cataract formation and does not impair the graft endothelium. Likewise, the rate of immunological graft rejections is not adversely affected by the excimer laser. In addition, trephination of an instable cornea is facilitated. Because of undisputed clinical advantages, especially in eyes with keratoconus, excimer laser trephination with orientation teeth/notches is still favored in Homburg/Saar in daily practice. The femtosecond laser (FSL)-assisted keratoplasty technique is very exciting but a prospective randomized study is required to determine potential benefits over excimer laser PKP.

  7. Diagnosis of arterial injuries caused by penetrating trauma to the neck: comparison of helical CT angiography and conventional angiography.

    PubMed

    Múnera, F; Soto, J A; Palacio, D; Velez, S M; Medina, E

    2000-08-01

    To determine the sensitivity and specificity of helical computed tomographic (CT) angiography in the diagnosis of carotid and vertebral arterial injuries caused by penetrating neck trauma. A prospective study was conducted during 24 months in 60 patients with penetrating neck trauma who were referred for conventional angiography owing to clinical suspicion of arterial injury. In the patient population, 146 arteries (77 carotid, 69 vertebral) were studied by means of conventional angiography. In all patients, conventional angiography and helical CT angiography were completed within 6 hours. Two radiologists interpreted helical CT angiographic studies by means of consensus. Conventional angiography was the standard of reference for determining the sensitivity and specificity of helical CT angiography. Conventional angiograms showed arterial injuries in 10 (17%) of 60 patients. Conventional angiographic findings were arterial occlusion (n = 4), arteriovenous fistula (n = 2), pseudoaneurysm (n = 3), pseudoaneurysm with arteriovenous fistula (n = 1), and normal arteries (n = 136). Nine of 10 arterial injuries and all normal arteries were depicted adequately at helical CT angiography. Sensitivity of helical CT angiography was 90%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 98%. The sensitivity and specificity of helical CT angiography are high for detection of major carotid and vertebral arterial injuries resulting from penetrating trauma.

  8. A case of acute postoperative keratitis after deep anterior lamellar keratoplasty by multidrug resistant Klebsiella

    PubMed Central

    Bajracharya, Leena; Sharma, Binita; Gurung, Reeta

    2015-01-01

    A healthy lady of 42 years underwent deep anterior lamellar keratoplasty for granular dystrophy. The very next day, it was complicated by development of infectious keratitis. The organism was identified as multidrug resistant Klebsiella pneumoniae. Donor corneal button may be implicated in the transmission of infection in an otherwise uneventful surgery and follow-up. Nosocomial infections are usually severe, rapidly progressive and difficult to treat. Finally, the lady had to undergo therapeutic penetrating keratoplasty for complete resolution of infection. PMID:26044477

  9. Evaluation of penetration and scattering components in conventional pinhole SPECT: phantom studies using Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Deloar, Hossain M.; Watabe, Hiroshi; Aoi, Toshiyuki; Iida, Hidehiro

    2003-04-01

    In quantitative pinhole SPECT, photon penetration through the collimator edges (penetration), and photon scattering by the object (object scatter) and collimator (collimator scatter) have not been investigated rigorously. Monte Carlo simulation was used to evaluate these three physical processes for different tungsten knife-edge pinhole collimators using uniform, hotspot and donut phantoms filled with 201Tl, 99mTc, 123I and 131I solutions. For the hotspot phantom, the penetration levels with respect to total counts for a 1 mm pinhole aperture were 78%, 28% and 23% for 131I, 123I and 99mTc, respectively. For a 2 mm aperture, these values were 65% for 131I, 16% for 123I and 12% for 99mTc. For all pinholes, 201Tl penetration was less than 4%. The evaluated scatter (from object and collimator) with a hotspot phantom for the 1 mm pinhole was 24%, 16%, 18% and 13% for 201Tl, 99mTc, 123I and 131I, respectively. Summation of the object and collimator scatter for the uniform phantom was approximately 20% higher than that for the hotspot phantom. Significant counts due to penetration and object and collimator scatter in the reconstructed image were observed inside the core of the donut phantom. The collimator scatter can be neglected for all isotopes used in this study except for 131I. Object scatter correction for all radionuclides used in this study is necessary and correction for the penetration contribution is necessary for all radionuclides but 201Tl.

  10. Repeat Keratoplasty for Failed Deep Anterior Lamellar Keratoplasty in Keratoconus: Incidence, Indications, and Outcomes.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad Ali; Khajuee-Kermani, Pejman; Jafari, Roya

    2017-05-01

    To analyze the incidence, indications, and clinical outcomes of penetrating keratoplasty (PK) and repeat deep anterior lamellar keratoplasty (DALK) after failed DALK for keratoconus. This retrospective interventional case series reviewed the medical records of patients with keratoconus who underwent DALK and were followed up for at least 1 year. Patients who underwent PK or repeat DALK for failed DALK were identified. The incidence, indications, and clinical outcomes after repeat keratoplasty were assessed. A total of 382 consecutive eyes with keratoconus underwent DALK over a 9-year period. Graft failure was observed in 14 eyes (3.7%). The reasons for the graft failure included nonhealing epithelial defects (n = 1), pseudoanterior chamber (n = 2), patient dissatisfaction with vision (n = 4), interface opacification (n = 4), high astigmatism (n = 1), and recurrence of keratoconus in the graft (n = 2). Of these 14 eyes with graft failure, 12 eyes underwent PK (n = 11) or repeat DALK (n = 1). At the most recent examination, which was performed 49.7 ± 25.2 months after the secondary graft, all regrafts were clear. There was no significant difference between eyes with clear first grafts and eyes that underwent PK or repeat DALK in visual outcomes at the final examination. Graft rejection was the most common complication, which was encountered in 75% of the regrafts. The prognosis for repeat keratoplasty was excellent, and the outcomes of secondary grafts were comparable to those of primary DALK grafts. However, the rate of rejection with secondary grafts was high, necessitating close follow-up after PK and repeat DALK performed for failed DALK.

  11. Crystal growth vs. conventional acid etching: a comparative evaluation of etch patterns, penetration depths, and bond strengths.

    PubMed

    Devanna, Raghu; Keluskar, K M

    2008-01-01

    The present study was undertaken to investigate the effect on enamel surface, penetration depth, and bond strength produced by 37% phosphoric acid and 20% sulfated polyacrylic acid as etching agents for direct bonding. Eighty teeth were used to study the efficacy of the etching agents on the enamel surface, penetration depth, and tensile bond strength. It was determined from the present study that a 30 sec application of 20% sulfated polyacrylic acid produced comparable etching topography with that of 37% phosphoric acid applied for 30 sec. The 37% phosphoric acid dissolves enamel to a greater extent than does the 20% sulfated polyacrylic acid. Instron Universal testing machine was used to evaluate the bond strengths of the two etching agents. Twenty percent sulfated polyacrylic acid provided adequate tensile bond strength. It was ascertained that crystal growth can be an alternative to conventional phosphoric acid etching as it dissolves lesser enamel and provides adequate tensile bond strength.

  12. [Keratoplasty classification and primary disease spectrum analysis of 315 cases].

    PubMed

    Cai, S B; Sun, M; Li, S; Xu, L J; Wang, W; Wang, J; Hu, W K; Li, X Y; Wang, P; Zhang, H; Li, G G

    2017-06-11

    Objective: To identify the primary disease spectrum and trends of surgical procedure of keratoplasty patients. Methods: Retrospective case series study. To review all patients who underwent keratoplasty at Department of ophthalmology in Tongji Hospital from January 1, 2012 to December 31, 2015. The data collected included age, sex, birthplace, and primary corneal disease and associated surgical procedures. Then the data were compared with similar papers domestic and foreign. Results: A total of 315 keratoplasties were performed during this 4-year period. The average age of patients at time of surgery was (42.0± 1.8) years, range from 33 days to 89 years, 229 cases (72.7%) were from 18 to 65 years; male: female ratio was 2.06:1. Totally 289 cases (91.8%)came from Hubei province, 26 cases (8.2%) were from other provinces. The leading indications for corneal transplantation were keratitis in 125 cases (39.7%), followed by corneal scar in 71 cases (22.5%), keratoconus in 41 cases (13.0%), pseudophakic bullous keratopathy in 26 cases (8.3%), corneal dermoid in 18 cases (5.7%), corneal dystrophy and degeneration in 16 cases (5.1%), and others (including chemical injuries, thermal burns, post-traumatic corneal scar and corneal opacity) in 18 cases (5.7%). Of the 125 keratitis cases, 51 cases (40.8%) were associated with fungus, 43 cases (34.4%)were associated with virus, and 24 cases (19.2%)were associated with bacterial. In accordance with the classification of corneal transplant surgery, penetrating keratoplasty was performed in 212 cases (67.3% ), lamellar keratoplasty was completed in 87 cases (27.6% ), corneal endothelial transplantation was made in 16 patients (5.1%). Conclusions: Infectious keratitis was the leading indication for corneal transplantation followed by corneal scar, keratoconus and pseudophakic bullous keratopathy in Tongji hospital patients who underwent keratoplasty. And fungus was the first cause of infectious keratitis. Penetrating keratoplasty

  13. Therapeutic and optical keratoplasty in the management of Acanthamoeba keratitis: risk factors, outcomes, and summary of the literature.

    PubMed

    Robaei, Dana; Carnt, Nicole; Minassian, Darwin C; Dart, John K G

    2015-01-01

    To report the risk factors for and outcomes of therapeutic and optical keratoplasty in the management of Acanthamoeba keratitis (AK). Retrospective case series. A total of 50 eyes of 196 patients with retrievable medical records, diagnosed with AK at Moorfields Eye Hospital, London, underwent keratoplasty between January 1991 and April 2012. Patient demographics, initial clinical examination findings, and management details were collected. The ophthalmic characteristics of patients who underwent keratoplasty for AK were compared with those who did not. Patients undergoing therapeutic keratoplasty were compared with those undergoing optical keratoplasty for baseline characteristics, management details, and visual outcomes. A multivariate logistic model was used to derive the odds ratios of a poor visual outcome in all keratoplasty patients. Poor visual outcome was defined as final visual acuity of 20/200 or worse. Secondary outcomes of interest included number of clinic visits and the need for additional intraocular surgery. Of the 196 AK patients, a total of 50 patients (25.5%) underwent penetrating or anterior lamellar keratoplasty, 10 of whom (20%) underwent repeat procedures. Of these 50 patients, 26 (52%) had therapeutic keratoplasty, predominantly for corneal perforation. The remaining 24 patients (48%) underwent optical keratoplasty for visual rehabilitation. Thirty-seven (80.4%) patients in the keratoplasty group initially were misdiagnosed as having herpes simplex keratitis versus 59 (41.8%) patients who did not require a keratoplasty (P < 0.001). Final visual outcomes were significantly better in the optical group compared with the therapeutic group, with 13 (54.2%) achieving visual acuity of 20/30 or better versus 7 (26.9%), respectively. On multivariate analysis, beginning therapy at a hospital other than Moorfields and undergoing a therapeutic, rather than an optical, keratoplasty were associated significantly with a poor visual outcome from

  14. Penetrator reliability investigation and design exploration : from conventional design processes to innovative uncertainty-capturing algorithms.

    SciTech Connect

    Martinez-Canales, Monica L.; Heaphy, Robert; Gramacy, Robert B.; Taddy, Matt; Chiesa, Michael L.; Thomas, Stephen W.; Swiler, Laura Painton; Hough, Patricia Diane; Lee, Herbert K. H.; Trucano, Timothy Guy; Gray, Genetha Anne

    2006-11-01

    This project focused on research and algorithmic development in optimization under uncertainty (OUU) problems driven by earth penetrator (EP) designs. While taking into account uncertainty, we addressed three challenges in current simulation-based engineering design and analysis processes. The first challenge required leveraging small local samples, already constructed by optimization algorithms, to build effective surrogate models. We used Gaussian Process (GP) models to construct these surrogates. We developed two OUU algorithms using 'local' GPs (OUU-LGP) and one OUU algorithm using 'global' GPs (OUU-GGP) that appear competitive or better than current methods. The second challenge was to develop a methodical design process based on multi-resolution, multi-fidelity models. We developed a Multi-Fidelity Bayesian Auto-regressive process (MF-BAP). The third challenge involved the development of tools that are computational feasible and accessible. We created MATLAB{reg_sign} and initial DAKOTA implementations of our algorithms.

  15. Comparison of a Supraglottic Gel Device and an Endotracheal Tube in Keratoplasty Performed Under General Anesthesia: A Randomized Clinical Trial.

    PubMed

    Guerrier, Gilles; Boutboul, David; Rondet, Sylvie; Hallal, Dalila; Levy, Jacques; Sjögren, Lea; Legeais, Jean-Marc; Nicolau, Romain; Mehanna, Chadi; Bourges, Jean-Louis; Samama, Charles Marc

    2016-01-01

    To assess the safety of a laryngeal mask (i-gel) in keratoplasty performed under general anesthesia. Patients with indications for keratoplasty (n = 110) were enrolled in a prospective study and randomly assigned to the i-gel (n = 55; 30 lamellar keratoplasty and 25 penetrating keratoplasty) or tracheal tube group (n = 55; 29 lamellar keratoplasty and 26 penetrating keratoplasty). Perioperative complications and the recovery time were compared between the 2 groups using the t test or χ(2) test. Contraindications to elective use of the laryngeal mask airway (esophageal reflux, extreme obesity, oropharyngeal pathology, or expected difficult intubation) and expected difficult intubation were excluded. No surgical perioperative complications were reported in either group. There was a significantly greater incidence of coughing at extubation and/or after extubation in the tracheal group (40/55; 73%) than in the laryngeal mask group (3/55; 5%) (P < 0.001). The recovery time was shorter in the i-gel group (80 minutes; 95% confidence interval, 75-86) compared with that in the tracheal tube group (88 minutes; 95% confidence interval, 82-95) (P = 0.03). There were no significant differences in the incidence of sore throat and hoarseness between both devices. The use of i-gel for keratoplasty under general anesthesia appears to be safe, reduces the risk of potential ocular hypertension during recovery, and saves recovery time.

  16. Corneal electrolysis for recurrence of corneal stromal dystrophy after keratoplasty

    PubMed Central

    Mashima, Y; Kawai, M; Yamada, M

    2002-01-01

    Aims: To evaluate corneal electrolysis as a treatment for recurrent diffuse corneal opacities at the host-graft interface of the stroma or at the subepithelial region in two types of granular corneal dystrophy (GCD). Methods: Recurrence developed at the host-graft interface of the stroma after lamellar keratoplasty in a patient with Avellino corneal dystrophy (ACD). At surgery, the deep aspect of the graft in this patient was partially separated from host tissue to expose the deposits, with one third of the host-graft junction left intact. The graft was everted, and electrolysis was applied directly to remove the deposits attached to both surfaces of the host and the graft. Then the graft was returned to its place and sutured. In two patients with homozygous ACD and one patient with the superficial variant of GCD, diffuse subepithelial opacities developed following penetrating keratoplasty. Electrolysis was applied directly to the corneal surface. Results: Deposits at the host-graft interface of the stroma and in the subepithelial region disappeared following treatment, and vision recovered in all patients. Conclusions: This method is a simple, easy, and inexpensive way to remove deposits that recur after lamellar or penetrating keratoplasty. PMID:11864880

  17. Acute hydrops after deep anterior lamellar keratoplasty in a patient with keratoconus.

    PubMed

    Javadi, Mohammad Ali; Feizi, Sepehr; Kanavi, Mozhgan Rezaei; Faramarzi, Amir; Hashemian, Javad; Mirbabaee, Firooz

    2011-05-01

    To report the occurrence of acute hydrops 52 months after successful deep anterior lamellar keratoplasty (DALK) using the Anwar big-bubble technique in a keratoconic eye. A 20-year-old man with a history of bilateral keratoconus who had undergone DALK in his right eye, presented with complaints of sudden visual reduction, photophobia, redness, and pain in the same eye. Review of his clinical course, slit-lamp biomicroscopy, and laboratory evaluation, including ultrasound biomicroscopy, revealed acute hydrops in the graft. He was medicated with hypertonic solutions but because of persistent graft edema and nonattached Descemet membrane, penetrating keratoplasty was performed. Histopathologic examination confirmed the diagnosis. Similar to penetrating keratoplasty, acute hydrops can occur after DALK using the big-bubble technique in patients with keratoconus.

  18. Enlarging the big-bubble during deep anterior lamellar keratoplasty.

    PubMed

    McKee, Hamish D; Jhanji, Vishal; Brahma, Arun K

    2013-04-01

    During big-bubble deep anterior lamellar keratoplasty, a bubble that is not large enough can be formed. Further air injection can result in the rupture of the posterior lamella, necessitating conversion to penetrating keratoplasty. We describe some techniques to safely enlarge the big-bubble in such a circumstance. In cases in which a white-margin bubble forms that has extended to the trephination margin, the bubble is collapsed and the margins are extended by blunt dissection. For cases of an undersized clear-margin bubble, the bubble is enlarged by gentle injection of a cohesive ophthalmic viscosurgical device into the bubble cavity. Using these techniques, big-bubbles were safely extended beyond the trephination margin for both white- and clear-margin bubbles. An undersized big-bubble can safely be extended using blunt dissection for white-margin bubbles and ophthalmic viscosurgical device injection for clear-margin bubbles.

  19. Laser Induced Thermal Keratoplasty

    NASA Astrophysics Data System (ADS)

    Householder, John; Horwitz, Larry S.; Lowe, Kenneth W.; Murrillo, Adolfo

    1989-09-01

    A technique of corneal surgery that is thermally induced and relatively nonenvasive has been studied by the authors, and the preliminary results of the thermal keratoplasty performed on live rabbits are reported here. A carbon dioxide laser was used with simple optical and pointing systems to thermally induce several arbitrary patterns of corneal reformation. Endothelial photographs were taken before the procedure and then again ten days after. They indicated no damage in the Descemet's membrane nor was there damage observed to the endothelium. As much, as 14 "diopters" of change occurred in the corneal keratometry with both positive and negative directions signs. The magnitude and direction of the change were recorded as functions of the pattern of the therapy produced and the laser energy deposited in the stroma. Any corneal reformation was tracked as a function of time subsequent to the procedure. A-minor decay was observed within the first three days of the procedure and the majority of the reformations have maintained at the time of this writing. Since radiation at this wavelength is highly attenuated and absorbed in cornea, no change was observed beyond mid-stroma and the lens and retina appeared uneffective. The authors believe that this technology will be a significant contributor to corneal refractive procedures in the near future. Unlike any refractive surgery currently practiced, this technology may lead to a procedure that: 1) is reversible, 2) is re.eatable, 3) stren thens rather then weakens the cornea, 4) is a..arentl more stable, 5) is more flexible in the types of corneal curvature changes it can produce, 6) results in very clean mires, 7) is painless, and 8) results in total corneal clarity.

  20. Ocular biomechanical measurements on post-keratoplasty corneas using a Scheimpflug-based noncontact device

    PubMed Central

    Modis, Laszlo; Hassan, Ziad; Szalai, Eszter; Flaskó, Zsuzsanna; Berta, Andras; Nemeth, Gabor

    2016-01-01

    AIM To analyse ocular biomechanical properties, central corneal thickness (CCT) and intraocular pressure (IOP) in post-keratoplasty eyes, as compared to normal subjects, with a new Scheimpflug-based technology. Moreover, biomechanical data were correlated with the size and age of the donor and recipient corneas. METHODS Measurements were conducted on 46 eyes of 46 healthy patients without any corneal pathology (age: 53.83±20.8y) and 30 eyes of 28 patients after penetrating keratoplasty (age: 49.43±21.34y). Ten biomechanical parameters, the CCT and IOP were recorded by corneal visualization scheimpflug technology (CorVis ST) using high-speed Scheimpflug imaging. Keratometry values were also recorded using Pentacam HR system. Scheimpflug measurements were performed after 43.41±40.17mo (range: 11-128mo) after the keratoplasty and after 7.64±2.34mo (range: 5-14mo) of suture removal. RESULTS Regarding the device-specific biomechanical parameters, the highest concavity time and radius values showed a significant decrease between these two groups (P=0.01 and P<0.001). None of other biomechanical parameters disclosed a significant difference. The CCT showed a significant difference between post-keratoplasty eyes as compared to normal subjects (P=0.003) using the CorVis ST device. The IOP was within the normal range in both groups (P=0.84). There were no significant relationships between the keratometric data, the size of the donor and recipient, age of the donor and recipient and biomechanical properties obtained by CorVis ST. CONCLUSION The ocular biomechanics remain stable after penetrating keratoplasty according to the CorVis ST measurements. Only two from the ten device-specific parameters have importance in the follow-up period after penetrating keratoplasty. PMID:26949641

  1. Tectonic Lamellar Keratoplasty Using Cryopreserved Cornea in a Large Descemetocele.

    PubMed

    Kim, Kang Yoon; Jung, Ji Won; Kim, Eung Kweon; Seo, Kyoung Yul; Kim, Tae Im

    2016-01-01

    We describe herein a case of an impending corneal perforation with a large descemetocele in a patient with previous penetrating keratoplasty (PKP) that subsequently was treated with an emergent lamellar keratoplasty using frozen preserved cornea. A 76-year-old male patient, who had a PKP, presented with a completely whitish and edematous graft accompanied by large epithelial defects. Although antibiotics and antiviral agents were tried for three days, the corneal stroma abruptly melted, except for the Descemet's membrane and endothelium. Cryopreserved corneal tissue that was kept at -80°C was thawed and sutured on top of the remaining Descemet's membrane and endothelium. Pathological and microbiological tests were conducted using the remaining donor and recipient corneal tissues. After tectonic corneal transplantation on top of a large descemetocele, a healthy graft and relatively clear interfaces between graft-host junctions were maintained without serious adverse reactions throughout 6 month follow-up period. Microbiological evaluations of donor tissue at the time of thawing and tissue preparation were done, and the results were all negative. Tissue that was taken intraoperatively from the recipient cornea also showed negative microbiological results. In conclusion, tectonic lamellar keratoplasty, using cryopreserved corneal tissue, only onto the remaining Descemet's membrane and endothelium in an emergent condition, was a safe and effective treatment.

  2. Vision-related quality of life before and after keratoplasty for Fuchs' endothelial dystrophy.

    PubMed

    Trousdale, Eleanor R; Hodge, David O; Baratz, Keith H; Maguire, Leo J; Bourne, William M; Patel, Sanjay V

    2014-11-01

    To assess vision-related quality of life in Fuchs' dystrophy and changes in vision-related quality of life after 3 types of keratoplasty (penetrating keratoplasty [PK], deep lamellar endothelial keratoplasty [DLEK], and Descemet stripping endothelial keratoplasty [DSEK]). Prospective, observational case series. Sixty-three subjects with Fuchs' endothelial dystrophy: 12 subjects (12 eyes) received PK, 11 subjects (11 eyes) received DLEK, and 40 subjects (40 eyes) received DSEK. Subjects were examined before keratoplasty and at regular intervals through 3 years after keratoplasty. At each examination, vision-related quality of life was assessed using the 25-item National Eye Institute Visual Functioning Questionnaire; best spectacle-corrected and uncorrected visual acuities were measured by using the electronic Early Treatment of Diabetic Retinopathy Study protocol; keratometric cylinder was measured by a manual keratometer. Disability glare was measured with a straylight meter. Vision-related quality of life composite score. Vision-related quality of life composite score for all eyes with Fuchs' dystrophy before keratoplasty was 72 ± 11 (n = 63) and did not differ between groups (P = 0.88). Vision-related quality of life improved by 6 months (PK, P = 0.008; DLEK, P = 0.03; DSEK, P < 0.001), with continued improvement between 6 months and 3 years after PK (P = 0.01) and DSEK (P = 0.004). At 6 months, the composite score was higher after DSEK than after PK (P = 0.006). At 3 years, there were no differences in composite scores between the 3 treatments (P = 0.33; mean minimum detectable difference, 8 [α = 0.05; β = 0.20]). After keratoplasty, quality of life was correlated with uncorrected visual acuity at 1 year (r = -0.38; P = 0.001) and at 3 years (r = -0.36; P = 0.02), with disability glare at 3 years (r = -0.41; P = 0.02), and with best-corrected visual acuity at 6 months (r = -0.34; P = 0.03), but not thereafter. Vision-related quality of life in patients with

  3. Efficacy and safety of femtosecond laser-assisted corneal endothelial keratoplasty: a randomized multicenter clinical trial.

    PubMed

    Cheng, Yanny Y Y; Schouten, Jan S A G; Tahzib, Nayyirih G; Wijdh, Robert-Jan; Pels, Elisabeth; van Cleynenbreugel, Hugo; Eggink, Catharina A; Rijneveld, Wilhelmina J; Nuijts, Rudy M M A

    2009-12-15

    To evaluate the efficacy and safety of femtosecond laser-assisted endothelial keratoplasty (FLEK) versus penetrating keratoplasty (PK) in patients with corneal endothelial disease. A randomized multicenter clinical trial of 80 eyes of 80 patients with corneal endothelial disease were randomized to FLEK or PK. Clinical outcomes (astigmatism and visual acuity) and incidence of postoperative complications were compared between the two groups. At 12 months, the percentage of eyes with a refractive astigmatism less than or equal to 3 diopters was higher in the FLEK group in comparison with the PK group (86.2% vs. 51.3%, P=0.004). The mean postoperative best corrected visual acuity was 20/70+/-2 lines in the FLEK group and 20/44+/-2 lines in the PK group (P<0.001), but the gain in the best corrected visual acuity between the two groups was not significantly different. The endothelial cell loss in the FLEK and PK group was 65+/-12% and 23+/-15% (P<0.001). The most common postoperative complication in the FLEK group was graft dislocation (27.8%). Wound healing related problems occurred in six eyes (15%) in the PK group and in none of the FLEK eyes. FLEK effectively reduces postoperative astigmatism and results in an absence of wound healing related problems in patients with endothelial disease. However, visual acuity is lower as compared with conventional PK, and the high level of endothelial cell loss warrants a modification of the insertion technique of the endothelial graft.

  4. Development of a nomogram for femtosecond laser astigmatic keratotomy for astigmatism after keratoplasty.

    PubMed

    St Clair, Ryan M; Sharma, Anushree; Huang, David; Yu, Fei; Goldich, Yakov; Rootman, David; Yoo, Sonia; Cabot, Florence; Jun, Jason; Zhang, Lijun; Aldave, Anthony J

    2016-04-01

    To develop a nomogram for femtosecond laser astigmatic keratotomy (AK) to treat post-keratoplasty astigmatism. Three academic medical centers. Retrospective interventional case series. A review of post-keratoplasty femtosecond laser AK was performed. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, and keratometry were recorded preoperatively and 1, 3, 6, and 12 months postoperatively. The location, length, depth, and diameter of the AK incisions were recorded, and the surgically induced astigmatic correction was related to these variables using regression analysis. One hundred forty femtosecond laser AK procedures were performed after penetrating keratoplasty (PKP) (n = 129) or deep anterior lamellar keratoplasty (DALK) (n =11), with 89 procedures (80 PKP, 9 DALK) included in the analysis. The mean CDVA improved from 20/59 (0.47 logMAR ± 0.38 [SD]) preoperatively to 20/45 (0.35 ± 0.31 logMAR) postoperatively (P = .013) (n = 46). The mean keratometric astigmatism decreased from 8.26 ± 2.90 diopters (D) preoperatively to 3.62 ± 2.59 D postoperatively (P < .0001) (n = 89). The mean refractive cylinder decreased from 6.77 ± 2.80 D preoperatively to 2.85 ± 2.57 D postoperatively (P < .0001) (n = 69). A nomogram for femtosecond laser AK to treat post-keratoplasty astigmatism was generated using regression analysis. Femtosecond laser AK significantly improved UDVA and CDVA and significantly reduced keratometric astigmatism and refractive cylinder after keratoplasty. The nomogram generated should improve the accuracy of post-keratoplasty femtosecond laser AK. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  5. Refractive keratoplasty. Keratophakia and keratomileusis.

    PubMed

    Troutman, R C; Swinger, C

    1982-01-01

    Early experience with the refractive keratoplasty techniques of José Barraquer--keratophakia and hypermetropic keratomileusis is presented. In contradistinction to the alloplastic lens substitutes currently being employed for the integral correction of aphakia, Barraquer's techniques would seem to offer a more permanent, more physiologic, full-time optical correction of the aphakic state. Their use is limited only by the condition of the patient's cornea and, in fact, may be applied not only in aphakia but also in phakic eyes with higher degrees of hyperopia or myopia. In the opinion of the authors, the refractive keratoplasty techniques of Barraquer can be performed by any well-instructed ophthalmic surgeon. These techniques offer to many patients a satisfactory, and potentially a physiologically superior alternative to alloplastic lens substitute for aphakic correction.

  6. Refractive keratoplasty: keratophakia and keratomileusis.

    PubMed

    Troutman, R C; Swinger, C

    1978-01-01

    We have presented our early experience with the refractive keratoplasty techniques of Doctor Jose Barraquer--keratophakia and hypermetropic keratomileusis. In contradistinction to the alloplastic lens substitutes currently being employed for the integral correction of aphakia, his techniques would seem to offer a more permanent, more physiologic, full-time optical correction of the aphakic state. Their use is limited only by the condition of the patient's corneaa and, in fact, may be applied not only in aphakia but also in phakic eyes with higher degrees of hyperopia or myopia. In the opinion of the authors, the refractive keratoplasty techniques of Barraquer can be perfored by any well-instructed ophthalmic surgeon. These techniques offer to many patients a satisfactory and potentially a physiologically superior alternative to alloplastic lens substitute for aphakic correction.

  7. Investigation on penetration of three conventional foodstuffs packaging polymers with two different thicknesses by larvae and adults of major species of stored-product pest insects.

    PubMed

    Allahvaisi, Somayeh; Purmirza, Ali Asghar; Safaralizade, Mohamad Hasan

    2009-01-01

    Despite modern methods of packaging, stored agricultural products are still under attack by stored-insect pests. Therefore, determination of the best polymer and appropriate thickness inhibiting the penetration of the insects must be considered. In this study, we investigated the ability of penetration and the rates of contamination by nine important stored product pest insects for three conventional flexible polymers (polyethylene, cellophane and polypropylene) at two thicknesses (16.5 and 29 microm), which are used as pouches for packing of agricultural products. We used adults of T. castaneum (Coleoptera), S. granarius (Coleoptera), R. dominica (Coleoptera), C. maculates (Coleoptera), O. surinamensis (Coleoptera), and larvae of P. interpunctella (Lepidoptera), E. kuehniella (Lepidoptera), S. cerealella (Lepidoptera) and T. granarium (Coleoptera). Results showed that for most of the species penetration occurred between 4 days and 2 weeks, but there were significant differences (p < or = 0.05) in the penetration of three polymers (cellophane, polyethylene and polypropylene) by the insects. Among the polymers, polyethylene with a thickness of 16.5 microm showed the highest degree of penetration and was the most unsuitable polymer for packaging of foodstuffs. Application of this polymer led to a complete infestation of the product and a lot of punctures were created by the insects. In contrast, no penetration was observed in polypropylene polymer with a thickness of 29 microm. Furthermore, adults and larvae of all species showed a much lower penetration when there was no food present in the pouches and this was the case for all polymers tested.

  8. Differential impact of high and low penetrance TNFRSF1A gene mutations on conventional and regulatory CD4+ T cell functions in TNFR1-associated periodic syndrome.

    PubMed

    Pucino, Valentina; Lucherini, Orso Maria; Perna, Francesco; Obici, Laura; Merlini, Giampaolo; Cattalini, Marco; La Torre, Francesco; Maggio, Maria Cristina; Lepore, Maria Teresa; Magnotti, Flora; Galgani, Mario; Galeazzi, Mauro; Marone, Gianni; De Rosa, Veronica; Talarico, Rosaria; Cantarini, Luca; Matarese, Giuseppe

    2016-05-01

    TNFR-associated periodic syndrome is an autoinflammatory disorder caused by autosomal-dominant mutations in TNFRSF1A, the gene encoding for TNFR superfamily 1A. The lack of knowledge in the field of TNFR-associated periodic syndrome biology is clear, particularly in the context of control of immune self-tolerance. We investigated how TNF-α/TNFR superfamily 1A signaling can affect T cell biology, focusing on conventional CD4(+)CD25(-) and regulatory CD4(+)CD25(+) T cell functions in patients with TNFR-associated periodic syndrome carrying either high or low penetrance TNFRSF1A mutations. Specifically, we observed that in high penetrance TNFR-associated periodic syndrome, at the molecular level, these alterations were secondary to a hyperactivation of the ERK1/2, STAT1/3/5, mammalian target of rapamycin, and NF-κB pathways in conventional T cells. In addition, these patients had a lower frequency of peripheral regulatory T cells, which also displayed a defective suppressive phenotype. These alterations were partially found in low penetrance TNFR-associated periodic syndrome, suggesting a specific link between the penetrance of the TNFRSF1A mutation and the observed T cell phenotype. Taken together, our data envision a novel role for adaptive immunity in the pathogenesis of TNFR-associated periodic syndrome involving both CD4(+) conventional T cells and Tregs, suggesting a novel mechanism of inflammation in the context of autoinflammatory disorders.

  9. Penetration Depth of Sodium Hypochlorite in Dentinal Tubules after Conventional Irrigation, Passive Ultrasonic Agitation and Nd:YAG Laser Activated Irrigation

    PubMed Central

    Ghorbanzadeh, Abdollah; Aminsobhani, Mohsen; Sohrabi, Khosro; Chiniforush, Nasim; Ghafari, Sarvenaz; Shamshiri, Ahmad Reza; Noroozi, Niusha

    2016-01-01

    Introduction: The penetration depth of irrigating solutions in dentinal tubules is limited; consequently, bacteria can remain inside dentinal tubules after the cleaning and shaping of the root canal system. Therefore, new irrigation systems are required to increase the penetration depth of irrigating solutions in dentinal tubules. Methods: A comparative study regarding the penetration depth of sodium hypochlorite (NaOCl) solution in dentinal tubules using four methods, (1) conventional irrigation (CI), (2) smear layer removal plus conventional irrigation (gold standard), (3) passive ultrasonic agitation (PUA) and (4) Nd:YAG laser activated irrigation (LAI), took place on 144 extracted mandibular teeth with a single root canal. After decoronation with a diamond disc and working length determination, the apical foramen was sealed with wax. The canals were prepared up to #35 Mtwo rotary file and 5.25% NaOCl was used for irrigation during preparation. To study the penetration depth of NaOCl, smear layer was eliminated in all samples. Dentinal tubules were stained with crystal violet and after longitudinal sectioning of teeth, the two halves were reassembled and root canal preparation was performed up to #40 Mtwo rotary file. Then the samples were distributed into four experimental groups. Depth of the bleached zone was evaluated by stereomicroscope (20X). Data were analyzed by Kruskal-Wallis test. Results: The highest and lowest average for NaOCl penetration depth in all three coronal, middle and apical sections belonged to CI + smear layer removal and CI. A statistically significant difference was seen when comparing the penetration depth of CI + smear layer removal group to CI and PUA groups in coronal and middle third, in which the average NaOCl penetration depth of the gold standard group was higher (P < 0.05). A statistically significant difference was seen between CI + smear layer removal group and the other three groups including CI, PUA and LAI in apical third

  10. [Effect of FK506 eye-drop combined with keratoplasty on recurrent Mooren's ulcer].

    PubMed

    Xie, Hanping; Chen, Jiaqi; Lin, Yuesheng; Liu, Yongmin; Ye, Chengtian

    2002-01-01

    To observe the effect of FK506 eye-drop combined with keratoplasty on recurrent Mooren's ulcer. 9 cases (15 eyes) of recurrent Mooren's ulcer were treated with topical FK506 eye-drop combined with keratoplasty. Of the 15 eyes, two of Mooren's ulcer smaller than half circle of the limbus were treated with 0.1% FK506 eye-drop. Among the other 13 eyes of the ulcer larger than half the circle of the limbus, 12 eyes were treated with excision of conjunctiva combined with lamellar keratoplasty. One eye with a central corneal perforation was treated with penetrating keratoplasty. FK506 eye-drop 0.1% was given to the 13 operated eyes after the re-epithelialization of the cornea. The effect of FK506 on recurrent Mooren's ulcer was observed. Measurements of FK506 in surgically resected cornea and conjunctiva, and aqueous humor of the operated eyes were performed using enzyme immunoassay procedure. Twelve cases of recurrent Mooren's ulcer treated with lamellar keratoplasty combined with topical 0.1% dexamethasone eye-drop were taken as control. After application of 0.1% FK506 eye-drop, concentrations of 30 - 350 ng/g of FK506 were found in the cornea and conjunctiva, and no FK506 was measured in the aqueous humor. Nine cases (15 eyes) of recurrent Mooren's ulcer were all cured and no recurrence was observed during the follow-up time of 12 - 17 months. The vision of 5 eyes was improved more than 2 lines after the treatment. Seven eyes of Mooren's ulcer in the control group recurred. 0.1% FK506 eye-drop combined with keratoplasty is an effective treatment for recurrent Mooren's ulcer.

  11. [Corneal transplantation in Hungary. Data of the National Keratoplasty Registry 1992-1996].

    PubMed

    Berta, A; Facskó, A; Kelenhegyi, C; Módis, L

    1997-06-29

    Upon the request of the National Transplantation Committee a nationwide keratoplasty register is functioning at the Department of Ophtalmology, University Medical School of Debrecen. Since then at the end of each year we collected data from the University Departments and Hospitals performing corneal transplantation concerning their keratoplasties and related activities. According to the acquired data the number of corneal transplantations performed in Hungary was 299 in 1992, 298 in 1993, 320 in 1994, 426 in 1995, and 479 in 1996. Keratoplasties in Hungary were performed in 6 University Departments and in 13 Hospitals, all together in 19 institutions in the past five years. The overwhelming majority of corneal transplantations (in 1995 95.8% and in 1996 96.4%) were penetrating keratoplasties. The ratios of lamellar keratoplasties in 1995 and in 1996 were 3.0% and 2.5%, respectively. The ratios of sclerokeratoplasties were slightly above 1% in both years. The distributions of implanted fresh and preserved (eye bank) corneas were around 50-50% in these two years so, that in 1995 a somewhat more and in 1996 somewhat less preserved corneas were used. This ratio for preserved corneas was less than 20% in the period between 1992 and 1994. The law regulating the procurement and the transplantation of corneas is based on presumed consent and explicit objection which is the better type of regulation for the performance of keratoplasties in large numbers. The number of corneal transplantations in Hungary in the past years was close to the figures of industrial countries (England, Germany) calculated for similar populations, inspite of the fact that financing was in many respects unacceptable.

  12. Root distribution in a California semi-arid oak savanna ecosystem as determined by conventional sampling and ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Koteen, L. E.; Raz-Yaseef, N.; Baldocchi, D. D.

    2011-12-01

    Koteen, Laura E., Raz-Yaseef, Naama, and Dennis D. Baldocchi University of California, Berkeley California's blue oak, Quercus douglasii, is a unique tree in several ways. Despite the intense heat of California's central valley and Sierra foothills, and absence of precipitation during dry summer months, blue oaks are winter deciduous, and rely on a suite of drought adaptation measures for highly-efficient water use. To date, much more is known about aboveground dynamics in semi-arid oak savanna ecosystems than belowground. Yet, the root system is instrumental in ensuring oak survival and in determining the magnitude and timing of land-atmospheric fluxes via its control of water and nutrient supply to aboveground processes and soil moisture content. Tree root distribution is notoriously heterogeneous. Therefore a comprehensive sampling effort is needed in order to optimally represent it. To further understand the patterns of water use in oak savanna ecosystems in the Sierra foothills of California, we have sought to characterize the root system by depth. To accomplish this goal, we have sampled the root system using conventional sampling methods (i.e. pit and core sampling), in conjunction with ground penetrating radar (GPR). Using both methods together made it possible to compensate for the limitations of each: Fine roots can only be detected by conventional sampling, and involve time intensive work in the lab, limiting sample size. GPR, on the other hand, allows for much greater spatial coverage and therefore more comprehensive characterization of the coarse root component. An extensive field campaign was executed during May 2011. 7 tree areas where chosen, representing the range of tree sizes and composition at the research site: 2 small trees, 2 large trees and 2 tree clusters. One additional very large tree that has undergone extensive additional physiological measurements was also chosen in order to posit and test hypotheses about linkages among root, soil

  13. Candida interface keratitis following deep anterior lamellar keratoplasty.

    PubMed

    Bahadir, Ayse E; Bozkurt, Tahir K; Kutan, Selda Aktay; Yanyali, Cemil A; Acar, Suphi

    2012-08-01

    The purpose is to report a case of Candida interface infection after deep anterior lamellar keratoplasty (DALK). A 23-year-old female patient underwent DALK surgery in the left eye for keratoconus. Four weeks after the surgery, she presented with asymptomatic white-cream colored deposits at the graft-host interface. Epithelial ingrowth was our first possible diagnosis because there were no symptoms or signs of inflammation. However, progression of the lesion under steroid treatment and the appearance of inflammation signs after tapering the steroid treatment raised suspicion of fungal keratitis. Anterior segment optical coherence tomography (OCT), ultrasound biomicroscopy, confocal microscopy and microbiologic examinations of the cornea were performed to evaluate the lesion. Anterior segment OCT and ultrasound biomicroscopy confirmed the lesion to be at the interface. The confocal scan disclosed hyper-reflective deposits and surrounding inflammatory cells but there were no hyphae-like structures. While taking a specimen from the lesion, the Descemet's membrane ruptured so a penetrating keratoplasty was performed. The microbiologic examination revealed Candida infection. Candida interface keratitis is a rare infection seen after DALK. The asymptomatic clinical picture and the similarity to epithelial ingrowth may postpone the diagnosis and consequently the treatment. Therefore, in cases of interface deposits seen after lamellar surgery, one should consider Candida interface keratitis.

  14. Traumatic keratoplasty rupture resulting from continuous positive airway pressure mask.

    PubMed

    Fiorentzis, Miltiadis; Seitz, Berthold; Viestenz, Arne

    2015-06-01

    To report a rare case of traumatic wound dehiscence caused by the use of a continuous positive airway pressure (CPAP) mask in a patient with chronic obstructive pulmonary disease (COPD) after penetrating keratoplasty (PKP). Observational case report. A 55-year-old man who was treated with uncomplicated PKP due to pellucid marginal corneal degeneration in the right eye 9 months earlier presented to the emergency department after a globe rupture caused by dislocation of his CPAP mask during sleep. The best-corrected visual acuity (BCVA) was light perception in the right eye. The corneal graft was dehisced from 12 over 3 to 6 o'clock (180 degrees) with interruption of the double running corneal sutures and nasal iris as well as vitreous incarceration. The graft was resutured in place with 33 interrupted 10-0 monofilament nylon sutures. The BCVA improved to 20/100 three months after globe reconstruction. This case underlines the necessity of education for patients undergoing keratoplasty regarding the use of protective eyewear, to avoid predictable or accidental ocular injuries and graft dehiscence or its subsequent consequences. CPAP masks should be fitted (eyeball sparing) to the margins of the orbit after PKP.

  15. Liquid-phase penetration under unsteady in-cylinder conditions: Soy- and Cuphea-derived biodiesel fuels vs. conventional diesel

    USDA-ARS?s Scientific Manuscript database

    Accelerated dilution of engine-lubrication oil is a significant potential issue when fueling with biodiesel. Biodiesel produced from some feedstocks is less volatile than conventional diesel, which makes wall-impingement of liquid fuel more likely, a problem that could be exacerbated by advanced in...

  16. The impact of tear functions on visual outcome following keratoplasty in eyes with keratoconus.

    PubMed

    Hara, Shuya; Kojima, Takashi; Dogru, Murat; Uchino, Yuichi; Goto, Eiki; Matsumoto, Yukihiro; Kawakita, Tetsuya; Tsubota, Kazuo; Shimazaki, Jun

    2013-07-01

    To investigate the impact of preoperative and postoperative tear functions on visual outcome and the recovery of visual function following keratoplasty in eyes with keratoconus. Twenty-five eyes of 25 consecutive patients (5 females, 20 males, mean age: 34.3 ± 15.8 years (range: 19-70 years) with keratoconus who underwent either penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK) were included in this prospective study. One patient who had a rejection episode during the follow-up period was excluded. All subjects underwent best corrected visual acuity (BCVA), corneal topography (refractive cylinder, surface regularity index: SRI and surface asymmetry index: SAI), Schirmer I test, tear film break-up time (BUT), corneal sensitivity, and fluorescein staining score measurements before as well as 1, 3, 6 and 12 months after keratoplasty. The relation between the tear functions and the duration until the achievement of maximum BCVA was also evaluated. Linear regression analysis was performed to study the statistical significance of the correlations and the time wise change of each examined parameter. SRI, SAI, and BCVA significantly improved after keratoplasty. The postoperative corneal sensitivity was still significantly low even at 12 months postoperatively. Postoperative BCVA at 3, 6 months and maximum BCVA showed a significant linear negative correlation with the preoperative BUT (3 months; r = -0.461, p = 0.036, 6 months; r = -0.494, p = 0.023, maximum BCVA; r = -0.473, p = 0.030). The duration until the achievement of maximum BCVA showed a significant negative correlation with the preoperative Schirmer test (r = -0.429, p = 0.036). BCVA at 1 and 3 months postoperatively showed significant linear negative correlations with BUT value at the respective periods (1 month; r = -0.665, p = 0.0036, 3 months; r = -0.580, p = 0.0059). Preoperative tear functions appeared to have an

  17. Intraoperative review of different bubble types formed during pneumodissection (big-bubble) deep anterior lamellar keratoplasty.

    PubMed

    Goweida, Mohamed Bahgat Badawi

    2015-06-01

    To evaluate the preoperative factors and intraoperative complications of the 2 bubble types formed during big-bubble deep anterior lamellar keratoplasty (DALK). This is a retrospective review of medical records of a series of patients who underwent DALK using the big-bubble technique from September 2009 to March 2014. A total of 134 eyes were included in this study-89 eyes with advanced keratoconus, 35 eyes with post-microbial keratitis corneal scars, 8 eyes with stromal dystrophies, and 2 eyes with post-laser in situ keratomileusis ectasia. A type 1 bubble (white margin) was achieved in 56 eyes (41.8%), whereas a type 2 bubble (clear margin) was formed in 14 eyes (10.4%) and a mixed bubble was formed in 2 eyes (1.5%). Big-bubble formation failed in 62 (46.3%). All eyes with the type 1 bubble were completed as DALK; microperforation occurred in 4 eyes. Twelve of 14 eyes with the type 2 bubble were converted to penetrating keratoplasty because of large perforations. The type 2 bubble is more likely to form in elderly patients and those with deep corneal scars and thin corneas. Because of the high rate of conversion to penetrating keratoplasty, better surgical strategies may be needed to manage type 2 bubbles.

  18. [Postoperative therapy after penetrating keratoplasty in herpes simplex keratitis].

    PubMed

    Süveges, Ildikó; Füst, Ágnes; Imre, László

    2013-12-29

    Bevezetés: A herpes simplex vírus által okozott szaruhártya-gyulladás a leggyakoribb oka a cornea centrumában kialakuló hegnek, amely látásvesztést okozhat. Célkitűzés: A szerzők célul tűzték ki a perforáló keratoplasztika eredményességének felmérését a szisztémás antiherpeses és immunszuppresszív terápia alkalmazásának tükrében. Módszer: Perforáló keratoplasztikán átesett 12 betegen végezték a retrospektív randomizált vizsgálatot. A műtéti beavatkozásig eltelt idő az első keratitis megjelenésétől számítva átlag 18 év volt (5–40 év). A műtéti indikáció 9 esetben a látás javítása, 3 esetben a cornea perforációjának megelőzése volt. Szisztémás kezelésként 9 beteg herpeszvírus elleni (acyclovir) és immunszuppresszív (mycophenolat mofetil), 2 beteg csak herpeszvírus elleni kezelést kapott, egy betegnél nem alkalmaztak szisztémás terápiát. Az átlagos követési idő 53,1 hónap volt (16–84 hó). Eredmények: A látásjavító célú 9 műtét közül 8 esetben a transzplantátum átlátszóan, ereződés nélkül gyógyult. Mind a 8 beteg acyclovir és mycophenolat mofetil kezelésben részesült. Egy esetben – amikor a beteg szisztémás kezelést nem kapott – recidíva és rejectio is fellépett. Az akut gyulladásos tünetekben végzett műtétek közül egyben gyógyult a transzplantátum átlátszóan, recidíva- és rejectiomentesen; a beteg acyclovir és mycophenolat mofetil terápiában részesült. Két esetben recidíva és rejectio is fellépett. Ezek közül egyben a beteg acyclovir és mycophenolat mofetil, egyben csak acyclovirkezelést kapott. A látóélesség minden esetben javult, 3 esetben a látást egyéb tényezők befolyásolták. Következtetések: A szisztémás acyclovir és mycophenolat mofetil terápia sikerrel alkalmazható herpes simplex keratitisben végzett perforáló keratoplasztikák után. Az acyclovir csökkenti a recidívák számát, a mycophenolat mofetil a transzplantátum rejectióját. A műtét időpontjának megválasztása döntő; a gyulladásmentes, heges állapotban végzett műtétek jobb eredménnyel kecsegtetnek. Orv. Hetil., 2013, 154(52), 2065–2070.

  19. [Risk factors and rejection frequency in patients undergoing penetrating keratoplasty].

    PubMed

    Gittins-Nuñez, Luis Othón; Díaz Del Castillo-Martín, Ernesto; Huerta-Albañil, Irma; Ríos-Prado, Rita; Soto-Dávila, Marco Antonio

    2016-01-01

    Introducción: el trasplante de córnea representa uno de los procedimientos quirúrgicos que con mayor frecuencia se realizan en todo el mundo y de los que tienen un mejor pronóstico. Dentro de sus principales indicaciones se encuentran: el queratocono, la queratopatía bullosa, el rechazo corneal previo, la distrofia corneal y la infección. Los factores de riesgo conocidos para rechazo del trasplante son: edad del receptor, presencia de vasos en la córnea receptora, presión intraocular y retrasplante. El objetivo de este artículo es determinar los factores de riesgo y la frecuencia de rechazo corneal en pacientes sometidos a queratoplastia penetrante. Métodos: el diseño del estudio fue descriptivo, observacional, transversal, retrospectivo y analítico. Se estudiaron los pacientes operados de queratoplastia penetrante en la consulta externa de córnea, con seguimiento mínimo de 6 meses. Se llevó a cabo una revisión de expedientes clínicos de pacientes operados de queratoplastia penetrante en Hospital de Especialidades del Centro Médico Nacional Siglo XXI del IMSS. Resultados: del total de los pacientes trasplantados 35.3 % presentaron rechazo del trasplante corneal. La neovascularización corneal previa al trasplante de la corona receptora estuvo presente en 21.3 %. Conclusiones: en nuestro estudio encontramos resultados similares a los reportados en la literatura, siendo los factores de riesgo más importantes para presentar rechazo: el uso de trépanos mayores a 7.50 mm, paciente con antecedentes de neovascularización corneal previa, queratopatía y queratitis herpética.

  20. Tectonic lamellar keratoplasty: simplified management of corneal perforations with an automated microkeratome.

    PubMed

    Park, Jonathan C; Habib, Nabil E

    2015-02-01

    To describe a simplified tectonic lamellar keratoplasty (LK) technique, which can be used to manage full-thickness corneal perforations. Case series demonstrating a new surgical technique. A 69-year-old female with rosacea keratitis and peripheral corneal perforation; a 49-year-old male with keratoconus, ipsilateral herpes simplex keratitis and an inferonasal corneal perforation; and a 12-year-old female with an apparently spontaneous central corneal perforation. These 3 patients with full-thickness corneal perforations were successfully managed with this automated tectonic LK technique. Tectonic LK has benefits relative to tectonic penetrating keratoplasty but remains unpopular because it is technically difficult to prepare the host and donor corneas. This tectonic LK technique negates the need for challenging free-hand dissection and gives an excellent donor fit to the host bed. This provides an easier and more effective way to manage corneal perforations. Copyright © 2015 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  1. Recurrent keratoconus in a corneal graft after deep anterior lamellar keratoplasty.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad-Ali; Rezaei Kanavi, Mozhgan

    2012-10-01

    To report the recurrence of keratoconus 49 months after deep anterior lamellar keratoplasty (DALK). A 21-year-old man with history of bilateral keratoconus who had undergone DALK in his right eye, presented with gradual visual loss 49 months after corneal transplantation. Slit lamp biomicroscopy revealed graft ectasia together with Vogt's striae in the posterior stroma and corneal topography demonstrated inferior steepening. With a diagnosis of recurrent keratoconus in the graft, the patient underwent penetrating keratoplasty (PK) and histopathological examination confirmed the diagnosis of keratoconus in the graft. Similar to PK, keratoconus can recur in the transplanted cornea after DALK. However, the time interval from transplantation to recurrence seems to be much shorter in DALK grafts.

  2. Development of Selective Lamellar Keratoplasty within an Asian Corneal Transplant Program: The Singapore Corneal Transplant Study (An American Ophthalmological Society Thesis)

    PubMed Central

    Tan, Donald; Ang, Marcus; Arundhati, Anshu; Khor, Wei-Boon

    2015-01-01

    Purpose: To evaluate outcomes of anterior lamellar keratoplasty (ALK) and endothelial keratoplasty (EK) within the Singapore Corneal Transplant Study (SCTS), with the hypothesis that both ALK and EK are able to provide equivalent or improved clinical outcomes, compared to penetrating keratoplasty (PK), and to determine changing trends globally with other international databases. Methods: Clinical data on all transplants performed was derived from our SCTS database, a prospective national keratoplasty registry, and clinical outcomes (graft survival, endothelial cell loss, complications, visual acuity) were compared between PK, ALK, and EK. Global trends on indications and forms of keratoplasty performed in 2011/2012 were obtained from national keratoplasty or eye banking registries, corneal/ophthalmological societies, national eye banks, and national ophthalmic institutions. Results: Global rates of EK surgery vary widely, from 52% (Sweden) to 0% (South Africa), with higher adoption by industrialized countries. ALK adoption rates similarly vary from 28.7% (China) to 1.0% (Philippines). SCTS data show high adoption rates in Singapore: EK 44% and ALK 28%. Our surgical modifications to big-bubble deep anterior lamellar keratoplasty (DALK) surgery resulted in visual outcomes matching PK, and a low conversion to PK of 2.1%, whereas our evolving approaches to donor insertion in Descemet’s stripping automated endothelial keratoplasty (DSAEK) show significant reduction in 1-year postoperative endothelial cell loss rates from 60% (folding), to 22% to 30% (Sheets Glide), to 15% (EndoGlide inserter). Conclusion: Improvements in various forms of ALK and EK surgery can lead to better visual outcomes, longer graft survival, and reduced complications, as compared to PK. Global trends suggest adoption of these procedures at different rates. PMID:26755854

  3. Expanding the scope of lamellar keratoplasty.

    PubMed Central

    Rich, L F

    1999-01-01

    PURPOSE: To investigate whether applications of current technology, such as cryolathe and excimer laser, might improve outcomes and increase use of lamellar keratoplasty. METHODS: Six studies were performed, beginning with animals and progressing to human subjects. The first study compared cryolathed with hand-dissected rabbit corneas to ascertain which created a smoother donor interface. The second animal pilot study was done to determine whether thickness of donor cornea resection could be accurately predicted with the cryolathe. A prospective animal trial was then undertaken to compare lamellar keratoplasty outcomes using cryolathed versus hand-dissected tissue. The fourth work extrapolated previous animal findings to lamellar keratoplasty in human disease. Finally, two ongoing studies are described. The first explores the possibility of sutureless lamellar keratoplasty. The second utilizes the excimer laser to dissect the recipient stromal bed. RESULTS: The initial animal pilot study demonstrated a clearer stromal surface in cryolathed versus hand-dissected corneal tissue. The second pilot showed that plano-powered donor tissue could be generated to predetermined thickness. The prospective animal trial revealed that clear grafts of intended thickness could be obtained with cryolathing. Human studies suggested that lamellar keratoplasty using cryolathe-prepared donor tissue may offer superior results to free-hand dissection. Finally, one ongoing study indicates that sutureless lamellar keratoplasty is untenable, and the other shows that clear grafts can be obtained by combining cryolathed donor tissue with recipient photoablation. CONCLUSION: This body of work demonstrates that use of new lamellar keratoplasty technology may offer expanded scope and better outcomes than traditional lamellar keratoplasty techniques. Images FIGURE 1 FIGURE 3 FIGURE 4A FIGURE 4B FIGURE 8A FIGURE 8B FIGURE 9 FIGURE 10 FIGURE 10B FIGURE 11A FIGURE 11B FIGURE 12A FIGURE 12B FIGURE 13

  4. Holographic neural networks versus conventional neural networks: a comparative evaluation for the classification of landmine targets in ground-penetrating radar images

    NASA Astrophysics Data System (ADS)

    Mudigonda, Naga R.; Kacelenga, Ray; Edwards, Mark

    2004-09-01

    This paper evaluates the performance of a holographic neural network in comparison with a conventional feedforward backpropagation neural network for the classification of landmine targets in ground penetrating radar images. The data used in the study was acquired from four different test sites using the landmine detection system developed by General Dynamics Canada Ltd., in collaboration with the Defense Research and Development Canada, Suffield. A set of seven features extracted for each detected alarm is used as stimulus inputs for the networks. The recall responses of the networks are then evaluated against the ground truth to declare true or false detections. The area computed under the receiver operating characteristic curve is used for comparative purposes. With a large dataset comprising of data from multiple sites, both the holographic and conventional networks showed comparable trends in recall accuracies with area values of 0.88 and 0.87, respectively. By using independent validation datasets, the holographic network"s generalization performance was observed to be better (mean area = 0.86) as compared to the conventional network (mean area = 0.82). Despite the widely publicized theoretical advantages of the holographic technology, use of more than the required number of cortical memory elements resulted in an over-fitting phenomenon of the holographic network.

  5. Indications, outcomes, and risk factors for failure in tectonic keratoplasty.

    PubMed

    Ang, Marcus; Mehta, Jodhbir S; Sng, Chelvin C A; Htoon, Hla Myint; Tan, Donald T H

    2012-07-01

    Outcomes of corneal transplantation for tectonic indications and risk factors for (tectonic and physiologic) graft failure. Retrospective cohort study. Consecutive patients who underwent keratoplasty for tectonic indications at the Singapore National Eye Centre (SNEC) between January 1, 1991, and December 1, 2009. Clinical data and donor and recipient characteristics were recorded and analyzed from subjects in the prospective Singapore Corneal Transplant Study. (1) Tectonic (anatomic) failure defined as recurrence of corneal melt threatening tectonic integrity and requiring additional corneal grafting within 3 months of the primary procedure. (2) Physiologic failure defined as irreversible change in graft clarity preventing recovery in useful vision in grafts initially clear 2 weeks postoperatively. The mean age of the study cohort (n = 362, 193 male and 169 female subjects) was 51.5 ± 20.2 years, with a mean follow-up of 25.8 ± 18.7 months. Patients underwent penetrating keratoplasty (PK) (n = 142, 39.2%), anterior lamellar keratoplasty (ALK) (n = 127, 35.1%), or a peripheral corneoscleral patch graft (n = 93, 25.7%) most commonly for inflammation (n = 68, 18.8%), trauma (n = 66, 18.2%), or infection (n = 66, 18.2%). Risk factors for tectonic failure (18/362 eyes, 5.0%) were severe lid disease (odds ratio [OR], 6.1; 95% confidence interval [CI], 1.7-22.1; P = 0.006), central ALK (OR, 7.5; 95% CI, 1.8-32.4; P = 0.007), and peripheral grafts (OR, 5.7; 95% CI, 1.1-28.3; P = 0.035). Among anatomically successful central grafts (n = 223), the mean physiological graft survival was 96 months (95% CI, 83-110); Kaplan-Meier probabilities for survival at 10 years were 66.8% for ALK and 44.2% for PK. Active corneal inflammation (hazard ratio [HR], 2.5; 95% CI, 1.4-4.4; P = 0.003) and larger donor and recipient graft sizes of ≥ 9 mm (HR, 17.9; 95% CI, 2.3-140.3; P = 0.006) were risk factors for physiologic graft failure in anatomically successful eyes with central

  6. Clinical results of non-Descemet stripping endothelial keratoplasty

    PubMed Central

    Zhang, Tao; Li, Shao-Wei; Chen, Tie-Hong; He, Jing-Liang; Kang, Yan-Wei; Lyu, Fang-Qi; Ning, Jian-Hua; Liu, Chang

    2017-01-01

    AIM To investigate the impact of non-Descemet stripping endothelial keratoplasty (non-DSEK) on graft rejection rate, and its overall procedural effectiveness in patients. METHODS Non-DSEK was performed on 65 eyes of 64 patients, and the procedural outcomes, including rejection episodes, failure and dislocation of the grafts, best corrected visual acuity (BCVA), endothelial cell density (ECD), and other complications, were analyzed retrospectively. RESULTS Of the 65 eyes, 63 recovered from bullous keratopathy with a clear cornea. The mean follow-up time was 26.4mo (range, 6-84mo). The mean BCVA improved from 1.70 logMAR preoperatively to 0.54 logMAR at 3mo, 0.46 logMAR at 6mo, and 0.37 logMAR at 1y after surgery. The postoperative donor ECD of the 25 patients who successfully underwent specular microscopic examination was 1918±534 cells/mm2 (range, 637 to 3056 cells/mm2), and the mean endothelial cell loss was 41.9% at 24mo postoperatively. One eye developed secondary glaucoma and required regrafting via penetrating keratoplasty (PKP). Another eye had postoperative graft failure due to rejection at 26mo. Postoperative graft dislocation occurred in eight eyes. All of the eight dislocated grafts were reattached using air reinjection. CONCLUSION Immunological graft rejection of the donor graft rarely occurs in non-DSEK. Therefore, non-DSEK is a safe, concise, and effective alternative to restore corneal decompensation when the Descemet membrane is disease-free. PMID:28251080

  7. Inadequate results for microkeratome-assisted additive stromal keratoplasty for management of keratoconus.

    PubMed

    Coullet, Julien; Fournié, Pierre; Malecaze, François; Arné, Jean-Louis

    2008-02-01

    To evaluate a new automated technique--microkeratome-assisted additive stromal keratoplasty (MASK)--for the management of keratoconus in eyes scheduled for surgery with clear cornea associated with total contact lens intolerance. This non-comparative, interventional case series included four eyes of four patients with stage I and II keratoconus associated with total contact lens intolerance. The first step of the surgical procedure consisted of performing a nasal-hinged flap on the host cornea with a microkeratome. The second step consisted of extracting a stromal piano-powered disk from the donor's cornea using an artificial chamber. The 80-microm thick lamellar graft was punched with a 7.5-mm circular trephine and positioned beneath the flap. Corneal refractive surgery was scheduled for the end of the sixth postoperative month. No corneal refractive surgery was performed after 6 months of follow-up. Only one eye gained five lines of best spectacle-corrected visual acuity (BSCVA). Among the other three eyes, two had unchanged BSCVA and one lost one line of BSCVA. At the end of surgery, mean corneal thickness was increased by 148.75 microm. Microkeratome-assisted additive stromal keratoplasty appears to be a safe and straightforward surgical technique that preserves the host endothelium and avoids the need of an open-sky procedure. However, in our study, MASK is not considered as an alternative to penetrating or deep lamellar keratoplasty in the management of keratoconus with clear cornea because of imprecise anatomic and refractive outcomes.

  8. Recurrence of Mooren's ulcer after lamellar keratoplasty.

    PubMed

    McDonnell, P J

    1989-09-01

    A 45-year-old man with unilateral Mooren's ulcer in a quiescent state underwent annular lamellar keratoplasty after corneal rupture due to minor trauma. Postoperatively, he did well until 8 months later when a recurrence of the Mooren's ulceration occurred, involving the central island of the patient's original corneal stroma. The stroma of the lamellar graft was uninvolved. This unusual occurrence lends support to the concept that there is a specific immunologic reaction to the cornea in patients with Mooren's ulcer.

  9. A Two-Piece Microkeratome-Assisted Mushroom Keratoplasty Improves the Outcomes and Survival of Grafts Performed in Eyes with Diseased Stroma and Healthy Endothelium (An American Ophthalmological Society Thesis)

    PubMed Central

    Busin, Massimo; Madi, Silvana; Scorcia, Vincenzo; Santorum, Paolo; Nahum, Yoav

    2015-01-01

    Purpose: To test the hypothesis that a new microkeratome-assisted penetrating keratoplasty (PK) technique employing transplantation of a two-piece mushroom-shaped graft may result in better visual outcomes and graft survival rates than those of conventional PK. Methods: Retrospective chart review of 96 eyes at low risk and 76 eyes at high risk for immunologic rejection (all with full-thickness central corneal opacity and otherwise healthy endothelium) undergoing mushroom PK between 2004 and 2012 at our Institution. Outcome measures were best-corrected visual acuity (BCVA), refraction, corneal topography, endothelial cell density, graft rejection, and survival probability. Results: Five years postoperatively, BCVA of 20/40 and 20/20 was recorded in 100% and over 50% of eyes, respectively. Mean spherical equivalent of refractive error did not vary significantly over a 5-year period; astigmatism averaged always below 4 diopters, with no statistically significant change over time, and was of the regular type in over 90% of eyes. Endothelial cell density decreased to about 40% of the eye bank count 2 years after mushroom PK and did not change significantly thereafter. Five years postoperatively, probabilities of graft immunologic rejection and graft survival were below 5% and above 95%, respectively. There was no statistically significant difference in endothelial cell loss, graft rejection, and survival probability between low-risk and high-risk subgroups. Conclusions: Refractive and visual outcomes of mushroom PK compare favorably with those of conventional full-thickness keratoplasty. In eyes at high risk for immunologic rejection, mushroom PK provides a considerably higher probability of graft survival than conventional PK. PMID:26538771

  10. A technique to salvage big-bubble deep anterior lamellar keratoplasty after inadvertent full-thickness trephination.

    PubMed

    Zarei-Ghanavati, Siamak; Zarei-Ghanavati, Mehran

    2011-01-01

    Herein we describe a technique for management of large inadvertent full-thickness trephination during deep anterior lamellar keratoplasty using the big-bubble technique without converting to penetrating keratoplasty. First, the anterior chamber is formed with an ophthalmic viscosurgical device (OVD). Then, the full-thickness wound is secured with one X-type 10-0 nylon suture. A 27-gauge needle is attached to a 2 ml air-filled syringe and inserted into the corneal stroma in the meridian opposite to the site of full-thickness trephination. Air is gently injected to produce a limited area of "big-bubble" detaching Descemet's membrane (DM) from the corneal stroma. The "big bubble" is slowly expanded with injection of OVD. Finally, the recipient stroma is removed, the donor lenticule is placed and the DM tear is secured with one full thickness 10-0 nylon suture.

  11. A Technique to Salvage Big-Bubble Deep Anterior Lamellar Keratoplasty after Inadvertent Full-Thickness Trephination

    PubMed Central

    Zarei-Ghanavati, Siamak; Zarei-Ghanavati, Mehran

    2011-01-01

    Herein we describe a technique for management of large inadvertent full-thickness trephination during deep anterior lamellar keratoplasty using the big-bubble technique without converting to penetrating keratoplasty. First, the anterior chamber is formed with an ophthalmic viscosurgical device (OVD). Then, the full-thickness wound is secured with one X-type 10-0 nylon suture. A 27-gauge needle is attached to a 2 ml air-filled syringe and inserted into the corneal stroma in the meridian opposite to the site of full-thickness trephination. Air is gently injected to produce a limited area of “big-bubble” detaching Descemet’s membrane (DM) from the corneal stroma. The “big bubble” is slowly expanded with injection of OVD. Finally, the recipient stroma is removed, the donor lenticule is placed and the DM tear is secured with one full thickness 10-0 nylon suture. PMID:22454710

  12. Femtosecond laser-assisted inverted mushroom keratoplasty.

    PubMed

    Cheng, Yanny Y Y; Tahzib, Nayyirih G; van Rij, Gabriel; van Cleynenbreugel, Hugo; Pels, Elisabeth; Hendrikse, Fred; Nuijts, Rudy

    2008-07-01

    To evaluate best-corrected visual acuity (BCVA), refractive outcome, corneal topography, optical coherence tomography, and endothelial cell density 12 months after femtosecond laser-assisted inverted mushroom keratoplasty. We performed a prospective study of a surgical case series of 5 patients undergoing femtosecond laser-assisted inverted mushroom keratoplasty for pseudophakic bullous keratopathy or pre-Descemet X-linked ichthyosis. The femtosecond laser was used to create a top-hat configuration in the donor cornea and recipient cornea. Laser parameters were as follows: energy, 4.0 (anterior inner vertical side cut and horizontal lamellar cut) and 7.0 microJ (posterior outer vertical side cut); spiral pattern with a firing rate of 15 kHz. The size of the anterior inner diameter was 7.4 mm in the donor cornea and 7.0 mm in the recipient cornea. The posterior outer diameter was 9.0 mm in all eyes. At 6 and 12 months after surgery, all corneal grafts were clear and showed an excellent adaptation of the lamellar donor and recipient wound surfaces. At 12 months postoperatively, BCVA averaged 20/32 (range, 20/60-20/20), refractive cylinder averaged -3.20 +/- 2.0 D, topographical cylinder averaged 3.26 +/- 2.1 D, and the mean endothelial cell density was 1793 +/- 491 cells/mm2 (range, 954-2237 cells/mm2). The mean central corneal thickness and thickness of the posterior shelf was 517 +/- 3 and 175 +/- 8 microm, respectively. The femtosecond laser-assisted inverted mushroom keratoplasty shows good promise in surgical treatment of corneal diseases. The multiplanar fit between the donor and recipient cornea allows early suture removal and visual rehabilitation.

  13. Boston type 1 keratoprosthesis for failed keratoplasty.

    PubMed

    Hager, Jonathan L; Phillips, David L; Goins, Kenneth M; Kitzmann, Anna S; Greiner, Mark A; Cohen, Alex W; Welder, Jeffrey D; Wagoner, Michael D

    2016-02-01

    The purpose of this study was to evaluate the outcomes of the Boston type 1 keratoprosthesis (Kpro-1) in eyes with failed keratoplasty. A retrospective review was performed of every patient treated with a Kpro-1 at a tertiary eye care center between January 1, 2008 and July 1, 2013. Eyes with a failed keratoplasty originally performed for corneal edema, trauma, or keratoconus were included in the statistical analysis. The main outcome measures were visual outcome, prosthesis retention, and postoperative complications. Twenty-four eyes met the inclusion criteria, including 13 eyes with corneal edema, 8 eyes with trauma, and 3 eyes with keratoconus. After a mean follow-up period of 28.9 months (range 7-63 months), the median best corrected visual acuity (BCVA) was 20/125. The BCVA was ≥ 20/40 in 4 (16.7 %) eyes, ≥ 20/70 in 9 (37.5 %) eyes, and ≥ 20/200 in 14 (58.3 %) eyes. Overall, the postoperative BCVA improved in 17 (70.9 %) eyes, was unchanged in 3 (12.5 %) eyes, and was worse in 4 (16.7 %) eyes. The initial Kpro-1 was retained in 22 (91.7 %) eyes, and was successfully repeated in the other 2 eyes. One or more serious prosthesis- or sight-threatening complications occurred in 8 (33.3 %) eyes. These included 1 case of wound dehiscence leading to prosthesis extrusion, 1 case of fungal keratitis leading to prosthesis extrusion, 4 cases of endophthalmitis, and 5 retinal detachments. The Boston Kpro-1 is associated with an excellent prognosis for prosthesis retention and satisfactory visual improvement in eyes with previous failed keratoplasty.

  14. Femtosecond-laser-assisted Descemet's stripping endothelial keratoplasty.

    PubMed

    Cheng, Yanny Y Y; Pels, Elisabeth; Nuijts, Rudy M M A

    2007-01-01

    To our knowledge, we describe the first patient with pseudophakic bullous keratoplasty treated with femtosecond-laser-assisted endothelial keratoplasty. A 5.5 mm corneoscleral tunnel incision was made; after Descemet's membrane was stripped, an 8.0 mm posterior lamellar corneal disk prepared with a femtosecond laser was inserted into the anterior chamber against the recipient cornea without the use of corneal sutures. Four months postoperatively, the posterior corneal disk was clear and the induced astigmatism was 2.1 diopters, demonstrating a functional corneal endothelial layer. The femtosecond laser offers a new surgical approach for minimally invasive endothelial keratoplasty in corneal endothelial disorders.

  15. Corneal Donor Tissue Preparation for Endothelial Keratoplasty

    PubMed Central

    Woodward, Maria A.; Titus, Michael; Mavin, Kyle; Shtein, Roni M.

    2012-01-01

    Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes1,2. Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK), transplanting only the posterior corneal stroma, Descemet's membrane, and endothelium, has dramatically changed treatment of corneal endothelial disease. DSEK is performed through a smaller incision; this technique avoids 'open sky' surgery with its risk of hemorrhage or expulsion, decreases the incidence of postoperative wound dehiscence, reduces unpredictable refractive outcomes, and may decrease the rate of transplant rejection3-6. Initially, cornea donor posterior lamellar dissection for DSEK was performed manually1 resulting in variable graft thickness and damage to the delicate corneal endothelial tissue during tissue processing. Automated lamellar dissection (Descemet's stripping automated endothelial keratoplasty, DSAEK) was developed to address these issues. Automated dissection utilizes the same technology as LASIK corneal flap creation with a mechanical microkeratome blade that helps to create uniform and thin tissue grafts for DSAEK surgery with minimal corneal endothelial cell loss in tissue processing. Eye banks have been providing full thickness corneas for surgical transplantation for many years. In 2006, eye banks began to develop methodologies for supplying precut corneal tissue for endothelial keratoplasty. With the input of corneal surgeons, eye banks have developed thorough protocols to safely and effectively prepare posterior lamellar tissue for DSAEK surgery. This can be performed preoperatively at the eye bank. Research shows no significant difference

  16. Trends in penetrating and anterior lamellar corneal grafting techniques for keratoconus: a national registry study.

    PubMed

    Godefrooij, Daniel A; Gans, Renze; Imhof, Saskia M; Wisse, Robert P L

    2016-08-01

    Keratoconus is a progressive disorder and one of the primary indications for corneal transplantation. Anterior lamellar keratoplasty offers several advantages over other techniques, including endothelial preservation and longer graft survival. In this study, we examined the recent trend of using lamellar techniques for keratoconus at a national level. Data were obtained from the Dutch national organ transplant database regarding corneal transplants for keratoconus performed in 2005 through 2014. Baseline characteristics for patients undergoing various techniques were obtained, and temporal trends were analysed. A total of 1041 operations were performed, including 736 penetrating keratoplasties (PKPs) and 297 anterior lamellar keratoplasties (ALKs). The mean age of the total surgical group was 37.4 ± 13.4 years, and 68% of patients were male (p = 0.0001). Preoperative patient characteristics were reported in all 1041 cases. The relative proportion of ALKs increased from 2005 (19% of cases) to 2010 (39% of cases) and remained approximately 30-40% thereafter. Descemet baring or deep anterior lamellar keratoplasty (DALK) was increasingly applied and was the predominant anterior lamellar technique performed from 2009 onwards. The number of corneal transplantations performed annually for keratoconus decreased during the past 10 years. Lamellar techniques were increasingly performed, accounting for approximately 35% of keratoplasties in 2010 and thereafter. Among ALK techniques, maximal depth DALK is the most prevalent keratoplasty performed for keratoconus in most recent years. Penetrating keratoplasty (PKP) is still common, with a stable frequency from 2010 onwards. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  17. Optical pachymetry-guided custom excimer laser-assisted lamellar keratoplasty for the surgical treatment of keratoconus.

    PubMed

    Spadea, Leopoldo; Gizzi, Riccardo; Evangelista Conocchia, Nicole; Urbano, Sara

    2012-09-01

    To evaluate the anatomic and functional results of optical pachymetry-guided custom excimer laser-assisted lamellar keratoplasty in keratoconus patients. Eye Clinic, University of L'Aquila, L'Aquila, Italy. Prospective noncomparative case series. Patients with keratoconus having unilateral surgery using custom excimer laser-assisted lamellar keratoplasty were evaluated. A transepithelial excimer laser ablation was planned to leave an estimated uniform thickness residual stromal corneal bed of 200 μm. The donor lamella was prepared with the excimer laser and subsequently sutured to the host cornea using 16 single 10-0 nylon sutures. The eyes were examined preoperatively and 3, 6, 12, and 24 months postoperatively. Outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, computerized videokeratography, pachymetry, and endothelial specular microscopy. Of the forty-three treated eyes, 35 were available at the 24-month follow-up visit, at which time the UDVA was better than 20/60 in 16 patients (45.7%) and the CDVA was 20/40 or better in 31 patients (88.6%). The mean refractive astigmatism was -2.11 diopters (D) (P<.05) and the mean spherical equivalent manifest refraction, -2.60 D (P<.05). No statistically significant changes in mean corneal endothelial cell density were observed postoperatively. In 1 case, the donor lamella was exchanged secondary to an altered reepithelialization process with initial corneal melting. Two-year findings indicate that pachymetry-guided custom excimer laser-assisted lamellar keratoplasty is a useful surgical treatment for moderate to advanced keratoconus, preventing the need for the more invasive procedure of penetrating keratoplasty. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. Air reinjection and endothelial cell density in Descemet membrane endothelial keratoplasty: five-year follow-up.

    PubMed

    Feng, Matthew T; Price, Marianne O; Miller, Jalee M; Price, Francis W

    2014-07-01

    To evaluate 5-year endothelial cell loss after Descemet membrane endothelial keratoplasty (DMEK), compare it with reported rates for Descemet-stripping endothelial keratoplasty (DSEK) and penetrating keratoplasty (PKP), and investigate potential association between cell loss and air reinjection. Price Vision Group, Indianapolis, Indiana, USA. Retrospective comparative case series. Consecutive DMEK procedures performed between March 2008 and April 2013 were reviewed. The inclusion criterion was at least 6 months of follow-up. Endothelial cell density was recorded preoperatively and 1, 3, and 6 months and annually through 5 years postoperatively. Potential association between air reinjection and endothelial cell loss was evaluated by repeated measures analysis of variance. Of the 926 procedures performed, 673 eyes met the inclusion criterion. Indications for DMEK included Fuchs dystrophy (n = 595), pseudophakic corneal edema (n = 30), failed endothelial keratoplasty (n = 39), and failed PKP (n = 9). The median endothelial cell loss was 26% at 1 month, increasing to 39% at 5 years in cross-sectional and longitudinal analyses. Cell loss was similar in eyes with no (n = 471) or 1 (n = 155) air reinjection and significantly higher in eyes with 2 or more air reinjections (n = 47, P=.017). The median 5-year cell loss of 39% with DMEK compared favorably with prior reports of DSEK (53%) and PKP (70%) performed for similar indications. Similar to DSEK, most DMEK cell loss was associated with the surgical procedure itself; subsequent cell loss occurred at a slower rate than after PKP. Cell loss was not significantly increased in eyes with a single air reinjection. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. [Update: Deep anterior lamellar keratoplasty (DALK) for keratoconus. When, how and why].

    PubMed

    Cursiefen, C; Schaub, F; Bachmann, B

    2016-03-01

    The treatment of keratoconus has been significantly expanded in recent years. In addition to the previous options for correction by fitting hard contact lenses and penetrating keratoplasty (PK), corneal cross-linking and lamellar transplantation techniques have been added. The aim of this review article is to highlight currently available options for minimization of complications and standardization of deep anterior lamellar keratoplasty (DALK) for keratoconus. This article summarizes our own data and gives a review of the literature in PubMed. Performing DALK can provide keratoconus patients with corneal grafts with considerably longer graft survival and a reduced risk of complications. The DALK procedure provides numerous advantages over PK, especially the reduced intraoperative opening of the eye, which thus reduces the risk of serious intraoperative complications. A further benefit is the complete absence of postoperative endothelial immune reactions as the recipient's endothelium remains untouched. The absence of endothelial immune reactions is especially advantageous for young patients with keratoconus and patients with an increased risk of graft rejection, e.g. in atopic dermatitis; however, there are also typical complications of DALK that do not occur during PK. The outlined strategies for standardization of DALK and avoidance of intraoperative and postoperative complications should make DALK safer and more reproducible and lead to possible establishment as a standard procedure in keratokonus.

  20. Clinical evaluation of Deep Anterior Lamellar Keratoplasty (DALK) for stromal corneal opacities

    PubMed Central

    Mathur, Vijay; Parihar, J.K.S.; Srivastava, V.K.; Avasthi, A.

    2012-01-01

    Background Corneal scars are commonly formed following many diseases of the eye like trauma, inflammation and infections. They lead to permanent diminution of vision which can be managed by Penetrating Keratoplasty (PK). PK is removing diseased as well as healthy tissues and is associated with many post-operative complications. Deep Anterior Lamellar Keratoplasty (DALK) is a relatively newer procedure which replaces only the diseased stroma, leaving the original corneal endothelium intact. This procedure is associated with lesser incidence of post-operative complications. Methods The study was conducted at a large tertiary care centre. 10 patients with stromal corneal scars were subjected to DALK and results were analysed after 06 months. Poor quality donor corneal tissue of B− and C grade was used in all cases. Results 7 out of 10 patients (70%) undergoing DALK had post-operative visual acuity of 6/24 or better. 03 patients who did not have adequate recovery of visual acuity were due to over-riding of the graft in 01 case (10%), fungal keratitis in 01 case (10%) and interface haze in 01 case (10%). Conclusion DALK is a promising new technique for management of superficial corneal stromal scars using poor quality donor corneal tissue. Initial results are encouraging with minimal complications. PMID:24532929

  1. Management of intra-Descemet membrane air bubble in big-bubble deep anterior lamellar keratoplasty.

    PubMed

    Sharma, Namrata; Swarup, Rishi; Bali, Shveta Jindal; Maharana, Prafulla; Titiyal, Jeewan S; Vajpayee, Rasik B

    2013-09-01

    To report the recognition and management of intra-Descemet membrane air bubble (IDMA) as a complication of big-bubble deep anterior lamellar keratoplasty (DALK). IDMA was present intraoperatively in 8 eyes after DALK. Indications for surgery were healed keratitis (n = 4), macular dystrophy (n = 2), and keratoconus (n = 2). The IDMA was present between the anterior banded layer and posterior nonbanded layer of Descemet membrane (DM). They were slid and displaced toward the peripheral cornea using 27-gauge cannula and punctured taking care that underlying DM was not ruptured. DM was bared in all eyes, and DALK was completed in 7 cases. One patient required conversion to penetrating keratoplasty because of macroperforation. No case had double anterior chamber. Mean follow-up was 13.9 ± 4.1 months. A DM fold was noted in 1 eye. Seven cases had postoperative best-corrected visual acuity of 20/60 or better. Prompt recognition of the IDMA intraoperatively is required, which can be managed successfully.

  2. Hydrophilic Acrylic Intraocular Lens Opacification after Descemet Stripping Automated Endothelial Keratoplasty

    PubMed Central

    Norouzpour, Amir; Zarei-Ghanavati, Siamak

    2016-01-01

    Purpose: To report hydrophilic acylic intraocular lens (IOL) opacification after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) in an eye with multiple prior intraocular surgeries and iatrogenic aniridia. Case Report: A 34-year-old woman with history of penetrating keratoplasty (PKP) for advanced keratoconus and subsequent Urrets-Zavalia Syndrome (UZS) underwent phacoemulsification and hydrophilic acrylic IOL implantation for her cataract. In order to control post-PKP glaucoma, multiple glaucoma surgeries including two glaucoma drainage implants were performed. As the original corneal graft failed, the patient subsequently underwent re-PKP. Four years later, she underwent DSAEK for treatment of the second graft failure. Ten months after DSAEK, a double semi-circular pattern of IOL opacification was observed on the anterior surface of the IOL. The patient did not report any complaints and we decided not to exchange the IOL. Conclusion: In an eye with UZS and iatrogenic aniridia, IOL opacification may result from direct contact between the IOL surface and exogenous air. Aniridia can be a risk factor for development of IOL opacification after DSAEK. Further studies are required to confirm this hypothesis. PMID:27413506

  3. Alternaria Keratitis after Deep Anterior Lamellar Keratoplasty

    PubMed Central

    Naik, Mekhla; Mohd. Shahbaaz; Sheth, Jay; Sunderamoorthy, S. K.

    2014-01-01

    To describe a case of Alternaria keratitis in a 30-year-old male patient who presented with bilateral vascularised central corneal opacity and underwent deep anterior lamellar keratoplasty (DALK) in the left eye. Patient was treated for recurrent epithelial defect with a bandage contact lens in the follow-up visits after DALK. Subsequently, patient presented with pigmented fungal keratitis, which on culture examination of the corneal scrapping demonstrated Alternaria species. Patient had to undergo a repeat DALK as the keratitis did not resolve with medical therapy alone. Patient did not have a recurrence for 11 months following the regraft. This case report highlights the importance of considering the Alternaria species as a possibile cause of non-resolving fungal keratitis after DALK. PMID:24669155

  4. Alternaria keratitis after deep anterior lamellar keratoplasty.

    PubMed

    Naik, Mekhla; Mohd Shahbaaz; Sheth, Jay; Sunderamoorthy, S K

    2014-01-01

    To describe a case of Alternaria keratitis in a 30-year-old male patient who presented with bilateral vascularised central corneal opacity and underwent deep anterior lamellar keratoplasty (DALK) in the left eye. Patient was treated for recurrent epithelial defect with a bandage contact lens in the follow-up visits after DALK. Subsequently, patient presented with pigmented fungal keratitis, which on culture examination of the corneal scrapping demonstrated Alternaria species. Patient had to undergo a repeat DALK as the keratitis did not resolve with medical therapy alone. Patient did not have a recurrence for 11 months following the regraft. This case report highlights the importance of considering the Alternaria species as a possibile cause of non-resolving fungal keratitis after DALK.

  5. Evolution of keratoplasty: from darkness to light.

    PubMed

    Bhartiya, Shibal; Gupta, Noopur

    2012-10-01

    The story of the evolution of corneal grafting reads like a modem day epic: Complete with a cast of larger than life heroes, brilliant and heroic feats, inspired by the mundane. The history is also peppered with dismal, heart rending failures, foolhardy ventures, and the ultimate triumph of the indomitable human spirit over all odds. This review aims to highlight the significant milestones in the rich history of corneal transplantation, and to pay tribute to the many inspired and dedicated pioneers in this field for their perseverance and superior wisdom. It is also a salute and memorial to the patients who reposed their trust in the corneal surgeons, subjecting themselves to the trauma of surgery, often with less than optimal results. It was their collective, relentless toil and dynamic vision which has resulted in the state of the art surgical techniques which are the basis of modern day keratoplasty.

  6. [Astigmatic keratotomy with the femtosecond laser: correction of high astigmatisms after keratoplasty].

    PubMed

    Kook, D; Bühren, J; Klaproth, O K; Bauch, A S; Derhartunian, V; Kohnen, T

    2011-02-01

    The purpose of this study was to evaluate a novel technique for the correction of postoperative astigmatism after penetrating keratoplasty with the use of the femtosecond laser creating astigmatic keratotomies (femto-AK) in the scope of a retrospective case series. Clinical data of ten eyes of nine patients with high residual astigmatism after penetrating keratoplasty undergoing paired femto-AK using a 60-kHz femtosecond laser (IntraLase™, AMO) were analyzed. A new software algorithm was used to create paired arcuate cuts deep into the donor corneal button with different cut angles. Target values were refraction, uncorrected visual acuity, best corrected visual acuity, topographic data (Orbscan®, Bausch & Lomb, Rochester, NY, USA), and corneal wavefront analysis using Visual Optics Lab (VOL)-Pro 7.14 Software (Sarver and Associates). Vector analysis was performed using the Holladay, Cravy and Koch formula. Statistical analysis was performed to detect significances between visits using Student's t test. All procedures were performed without any major complications. The mean follow-up was 13 months. The mean patient age was 48.7 years. The preoperative mean uncorrected visual acuity (logMAR) was 1.27, best corrected visual acuity 0.55, mean subjective cylinder -7.4 D, and mean topometric astigmatism 9.3 D. The postoperative mean uncorrected visual acuity (logMAR) was 1.12, best corrected visual acuity 0.47, mean subjective cylinder -4.1 D, and mean topometric astigmatism 6.5 D. Differences between corneal higher order aberrations showed a high standard deviation and were therefore not statistically significant. Astigmatic keratotomy using the femtosecond laser seems to be a safe and effective tool for the correction of higher corneal astigmatisms. Due to the biomechanical properties of the cornea and missing empirical data for the novel femto-AK technology, higher numbers of patients are necessary to develop optimal treatment nomograms.

  7. Contact Lens Visual Rehabilitation in Keratoconus and Corneal Keratoplasty

    PubMed Central

    Ozkurt, Yelda; Atakan, Mehmet; Gencaga, Tugba; Akkaya, Sezen

    2012-01-01

    Keratoconus is the most common corneal distrophy. It's a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty. PMID:22292112

  8. Indications for Keratoplasty at 3 Academic Centers from 2002 to 2012.

    PubMed

    Hsu, Kimberly M; Chang, Shu-Hong; Brothers, Whitney; Edelstein, Sean L; Hsu, Hugo Y; Harocopos, George J

    2016-11-01

    To determine whether indications for keratoplasty differ between academic centers and the Eye Bank Association of America (EBAA) annual statistics from 2002 to 2012. A retrospective review was performed for the indications for keratoplasty from 2002 to 2012 based on surgical specimens originating from three different academic centers. Data were compared with statistical reports obtained from the EBAA for the corresponding years. From 2002 to 2007, at Washington University in St Louis (WU), the most common indication for keratoplasty was graft failure at 31.6%. At St Louis University, the most common indications for keratoplasty were pseudophakic and aphakic bullous keratopathy (PBK/ABK) at 34.6% followed closely by graft failure at 32.7%. Combining the 2002 to 2007 EBAA data, the most common indication for keratoplasty was PBK/ABK at 19.5%, whereas regrafts accounted for only 13.0% of keratoplasties. From 2008 to 2012, regrafts accounted for 41.9% of keratoplasties at WU and 33.1% of keratoplasties at University of California, Davis. In contrast, the EBAA data showed that only 11.4% of keratoplasties were regrafts. Graft failure accounted for approximately 30% to 40% of indications for keratoplasties at three academic centers from 2002 to 2012, which was more than double and in some cases triple that of the EBAA data during this period. These higher frequencies of regrafting may represent a referral bias of patients with complicated cases to academic centers who then require multiple keratoplasties.

  9. Liquid penetrants

    NASA Technical Reports Server (NTRS)

    Pasley, R. L.

    1973-01-01

    Liquid-penetrant inspection is discussed for surface defects in solids. The principle advantages are considered to be its simplicity and economy. The techniques and penetrants are described along with the developers. Commercially available equipment is also described.

  10. Severe penetrating ocular injury from ninja stars in two children.

    PubMed

    Jeng, B H; Steinemann, T L; Henry, P; Brodsky, M C

    2001-01-01

    The authors describe two cases of penetrating ocular trauma in children resulting from ninja stars. In the first case, despite a scleral laceration, loss of iris tissue, and a vitreous hemorrhage, the child had a good result with a final best corrected visual acuity of 20/20. Unfortunately, the child in the second case did not fare as well. In this case, the child suffered a large corneal laceration and traumatic cataract. He ultimately required a penetrating keratoplasty, and he is currently being treated for amblyopia, strabismus, and elevated intraocular pressures. His best corrected visual acuity is 20/70.

  11. Excimer laser smoothing of endothelial keratoplasty grafts.

    PubMed

    Cleary, Catherine; Liu, Ying; Tang, Maolong; Li, Yan; Stoeger, Christopher; Huang, David

    2012-04-01

    To use excimer laser smoothing passes to reshape Descemet-stripping automated endothelial keratoplasty (DSAEK) endothelial grafts and to evaluate the effect on the donor endothelium. The stromal surface of microkeratome-cut DSAEK grafts was smoothed using excimer laser smoothing passes with masking fluid. Excimer laser hyperopic ablation was used to improve the uniformity of graft thickness within the optical zone. Fourier-domain optical coherence tomography was used to measure endothelial graft pachymetry, plan ablations, and evaluate donor contour. Vital dye staining was performed to assess endothelial cell damage. Scanning electron microscopy images of stromal surfaces were graded on a 5-point scale by masked observers to evaluate surface roughness. Four grafts underwent excimer laser smoothing. Vital dye staining showed no endothelial damage. Microkeratome-cut surfaces treated with laser smoothing (mean grade = 2.04) were smoother than nonsmoothed microkeratome-cut surfaces (mean grade = 4.07; P < 0.01), surfaces that underwent dry laser ablation (mean grade = 3.63; P < 0.01) and manually dissected interfaces (mean grade = 4.75; P < 0.0001). No difference was observed between stromal beds created by peeling Descemet membrane (mean grade = 1.64) compared with surfaces produced by microkeratome cutting followed by laser smoothing (mean grade = 2.04; P = 0.14). One graft underwent combined excimer smoothing and peripheral hyperopic ablation. The center-periphery thickness difference was 15 μm before ablation and 4 μm afterward. Laser smoothing passes can be used to improve the contour and smoothness of DSAEK grafts without damaging donor endothelial cells. Clinical trials are needed to determine whether reshaping donors using excimer laser can deliver improved visual outcomes after DSAEK.

  12. Effect of corneal collagen crosslinking on subsequent deep anterior lamellar keratoplasty (DALK) in keratoconus.

    PubMed

    Schaub, Friederike; Enders, Philip; Bachmann, Björn O; Heindl, Ludwig M; Cursiefen, Claus

    2017-04-01

    The purpose was to investigate the impact of ultraviolet light corneal collagen crosslinking (UV-CXL) on the success rate and clinical outcome of subsequent deep anterior lamellar keratoplasty (DALK) in eyes with keratoconus (KC). Medical records of 101 consecutive eyes with KC scheduled for big-bubble DALK surgery were screened retrospectively for details of previously performed UV-CXL, as well as intra- and postoperative complications of DALK surgery. Main outcome measures were intraoperative success rates (big-bubble formation, conversion to penetrating keratoplasty (PK)), postoperative complications, best corrected visual acuity (BCVA), endothelial cell density (ECD), and central corneal thickness (CCT) within 18 months of follow-up. Out of the 101 KC eyes, eight eyes (7.9%) had a history of previous UV-CXL. Surgical failure, defined as conversion to PK due to macroperforation, occurred in 17 eyes (16.8%) of 93 eyes without and in none with previous UV-CXL (P < .001). Failure to achieve a big-bubble occurred in 37 eyes (40.2%) without previous UV-CXL and in two eyes (25%) with previous UV-CXL. Microperforations of Descemet's membrane were observed in ten eyes (20.7%) without and in 14 eyes (15.2%) with previous UV-CXL (P = .16). No significant differences could be detected for either the postoperative complication rate (P ≥ .18) or the clinical outcome parameters at 18 months follow-up, including BCVA, ECD and CCT (P ≥ .08) for eyes with or without UV-CXL. In DALK surgery, prior UV-CXL does not seem to affect the rate of intra- or postoperative complications, the success rate, or its clinical outcome.

  13. [Excimer laser-assisted lamellar endothelial keratoplasty (ExALEK): Technique and results].

    PubMed

    Bonissent, A; Vabres, B; Orignac, I; Martin, E; Libeau, L; Heymann, D; Ducourneau, Y; Weber, M

    2016-02-01

    The purpose of this study is to describe a technique for thin endothelial lamellar keratoplasty and to present the results for endothelial transplant performed at the University Hospital of Nantes. This paper is a retrospective, single-center descriptive study conducted at the University Hospital of Nantes from September 2010 to May 2014, at first for anatomical or analgesic indications (group 1) and then extended to visual indications (group 2). Patients were followed for 12 months. The preparation of the endothelial graft includes an excimer-laser ablation of the residual stromal bed after lamellar keratectomy by manual deep anterior approach. Seventy surgeries were analyzed. The etiologies were mainly Fuchs Dystrophy, secondary endothelial dystrophy and post-penetrating keratoplasty endothelial failure. Fifty-three patients were integrated in group 1 and seventeen patients in group 2. In group 1, the mean VA at 12 months was 0.70 ± 0.30 Log MAR (0.2 decimal equivalent). In group 2, the mean VA at 12 months was 0.28 ± 0.12 Log MAR (0.5 decimal equivalent). Pachymetry decreased from 740 ± 125.1 μm preoperatively to 613.4 ± 73.4 μm at 12 months. The average central thickness of the graft was 84.1 ± 28.9 μm at 1 month and 80.2 ± 29.4 μm at 12 months. The advantage of this new surgical technique is that it is a rapid and repeatable method allowing thin grafts with satisfactory functionality and easy handling. Its performance independent of the scheduled surgery, allows for predictable organization in the operating room. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  14. Pachymetry-guided intrastromal air injection ("pachy-bubble") for deep anterior lamellar keratoplasty.

    PubMed

    Ghanem, Ramon C; Ghanem, Marcielle A

    2012-09-01

    To evaluate an innovative technique for intrastromal air injection to achieve deep anterior lamellar keratoplasty (DALK) with bare Descemet membrane (DM). Thirty-four eyes with anterior corneal pathology, including 27 with keratoconus, underwent DALK. After 400 μm trephination with a suction trephine, ultrasound pachymetry was performed 0.8 mm internally from the trephination groove in the 11 to 1 o'clock position. In this area, a 2-mm incision was created, parallel to the groove, with a micrometer diamond knife calibrated to 90% depth of the thinnest measurement. A cannula was inserted through the incision and 0.5 mL of air was injected to dissect the DM from the stroma. After peripheral paracentesis, anterior keratectomy was carried out to bare the DM. A 0.25-mm oversized graft was sutured in place. Overall, 94.1% of eyes achieved DALK. Bare DM was achieved in 30 eyes, and a pre-DM dissection was performed in 2 eyes. Air injection was successful in detaching the DM (achieving the big bubble) in 88.2% of the eyes. In keratoconus eyes, the rate was 88.9%. All cases but one required a single air injection to achieve DM detachment. Microperforations occurred in 5 cases: 3 during manual layer-by-layer dissection after air injection failed to detach the DM, 1 during removal of the residual stroma after big-bubble formation, and 1 during the diamond knife incision. Two cases (5.9%) were converted to penetrating keratoplasty because of macroperforations. The technique was reproducible, safe, and highly effective in promoting DALK with bare DM.

  15. [Microkeratome and excimer laser-assisted endothelial keratoplasty (MELEK)].

    PubMed

    Thannhäuser, C L; Palka, K; Herbst, H; Schroeter, J; Pham, D T

    2014-10-01

    Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) have become well established procedures for the treatment of endothelial pathologies. In the last years the field of lamellar corneal surgery has further developed in terms of preparation of the lamellae as well as of implantation. A modified form of the "ultrathin DSAEK" (UT-DSAEK) is the "microkeratome and excimer laser-assisted endothelial keratoplasty" (MELEK). In this new technique a corneal graft is prepared by a single cut of a microkeratome followed by a stromal excimer-laser thinning and smoothing. The purpose of the present report is to describe this new technique and present first clinical results. In this prospective clinical study 18 patients (76 ± 11 years) underwent a MELEK. The BCVA increased from 0.25 ± 0.1 preoperatively to one month postoperatively was 0.33 ± 0.21 (decimal, n = 12), after three months 0.51 ± 0.23 (n = 8) and after six months 0.80 ± 0.16 (n = 4). The average thickness of the residual stromal lamella before laser ablation was 173 ± 42 µm, after ablation 111 ± 15 µm. The central corneal thickness decreased from 704 µm to 639 µm, the thickness of the transplant decreased from 114 µm to 106 µm six months postoperatively. The ultrathin "microkeratome and excimer laser-assisted endothelial keratoplasty" (MELEK) is a new and safe technique in the field of lamellar keratoplasty. In the future it could have the potential to combine the advantages of DSAEK and DMEK for the treatment of endothelial pathologies. Georg Thieme Verlag KG Stuttgart · New York.

  16. Late spontaneous resolution of a double anterior chamber post deep anterior lamellar keratoplasty.

    PubMed

    Passani, Andrea; Sframeli, Angela Tindara; Loiudice, Pasquale; Nardi, Marco

    2017-01-01

    A 31-year-old healthy male underwent deep anterior lamellar keratoplasty with big-bubble technique for treatment of keratoconus in his right eye. One week after surgery, he presented with detachment of the endothelium-Descemet complex with formation of a double anterior chamber, despite the apparent absence of an intraoperative Descemet membrane rupture. A subsequent intervention with the intent to relocate the corneal graft button was not effective, because the detachment appeared again one day later. The authors hypothesized that, at the time of the stromal dissection with big bubble technique, a small amount of air penetrated into the anterior chamber, creating a false pathway through the trabecular meshwork. The aqueous humor then penetrated the graft flowing through the false pathway, causing the endothelium-Descemet detachment. The persistence of that pathway, even after the intervention of graft repositioning, caused the failure of the latter procedure and persistence of the double chamber. We decided to wait and observe. The double anterior chamber spontaneously resolved in approximately three months.

  17. Penetration equations

    SciTech Connect

    Young, C.W.

    1997-10-01

    In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.

  18. [Suture loosening after keratoplasty and methods for correction (author's transl)].

    PubMed

    Mackensen, G; Haug, H P; Horn, C; Sundmacher, R; Witschel, H

    1978-11-01

    An analysis of histological and clinical findings in 102 keratoplasties confirms that suture loosening is often associated with defects found in Bowman's membrane and in the superficial stroma. These structures of the cornea serve as the major supporting layer for a suture. In cases of more generally weakened corneal tissue, like in keratokonus, suture loosening is also a relatively frequent occurance. In this paper we report on our experiences with correction methods, post-operative care and immunoprophylaxis after correction.

  19. Survey of Experts on Current Endothelial Keratoplasty Techniques

    PubMed Central

    Chamberlain, Winston; Austin, Ariana; Terry, Mark; Jeng, Bennie H; Rose-Nussbaumer, Jennifer

    2016-01-01

    Objective To survey cornea specialists’ opinions on different endothelial keratoplasty techniques and to gauge the perceived need for and utility of a randomized controlled trial (RCT) comparing them. Methods A short survey was distributed to a group of cornea specialists at the Endothelial Keratoplasty Group meeting at the American Academy of Ophthalmology meeting in November 2015. Results Thirty-three of 80 practicing surgeons present at the EKG meeting participated in the survey, yielding a response rate of 41%. Ninety-seven percent (n=32) of our respondents reported performing Descemet’s Stripping Endothelial Keratoplasty (DSEK) regularly, and 70% reported having performed Descemet’s Membrane Endothelial Keratoplasty (DMEK) at least once (n=23). While most respondents (n=26, 79%) thought there was at least some evidence that DMEK is superior to DSEK in terms of visual acuity, there was less certainty about comparing ultrathin-DSEK (UT-DSEK) to DMEK with 48% (n=16) thinking there was at least some evidence of DMEK’s superiority, 6% (n=2) thinking there was at least some evidence of UT-DSEK’s superiority, and 30% (n=10) unsure. Seventy-two percent (n=23) of respondents thought an RCT comparing visual acuity outcomes in UT-DSEK versus DMEK would be at least moderately beneficial, and 82% (n=27) reported they were at least moderately likely to change their EK technique based on the results of said RCT. Conclusion There is substantial interest in an RCT comparing visual acuity outcomes in UT-DSEK versus DMEK. PMID:28149669

  20. Changes in keratometric corneal power and refractive error after laser thermal keratoplasty.

    PubMed

    Park, Choul Yong; Ji, Yong Hoon; Chung, Eui-Sang

    2004-04-01

    To evaluate the effect of laser thermal keratoplasty (LTK) on corneal power and refractive error to develop a logical approach to calculating accurate intraocular lens (IOL) power for cataract surgery. Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Laser thermal keratoplasty was performed in 27 eyes of 23 patients. Preoperatively and postoperatively, the refractive error was measured and the corneal power obtained by manual keratometry and topography. The changes in keratometric corneal power and refractive error after LTK were compared. The mean age of the 15 women and 8 men was 45.0 years +/- 4.6 (SD) (range 43 to 61 years). The mean preoperative refractive error was +1.43 +/- 0.97 diopters (D) (range 0 to +3.63 D) at the spectacle plane and +1.46 +/- 1.01 D (range 0 to +3.79 D) at the corneal plane. The mean postoperative refractive error was -0.44 +/- 1.07 D (range -2.24 to +2.18 D) at the spectacle plane and -0.44 +/- 1.08 D (range -2.18 to +2.23 D) at the corneal plane. After surgery, corneal powers measured by manual keratometry were significantly smaller than those measured by topography (P<.001) and refractive error changes were significantly smaller than keratometric changes (P<.001). After LTK, corneal power measured by manual keratometry was smaller than that measured by corneal topography and changes in corneal power measured by conventional keratometric instruments were greater than changes in refractive error. This difference should be considered in calculating IOL power in post-LTK eyes to prevent undesirable hyperopia after cataract surgery.

  1. Ground Shock from Penetrating Conventional Weapons

    DTIC Science & Technology

    1983-05-01

    Soil conditions ranged from loose dry sand to Significant enhancement of the stresses and saturated clay. Empirical equations are pre- ground motions...expected stresses and ground before it denotates. Often, protective layers of motions as a function of burst position, soil concrete or rock rubble are ...loading are : a) weapon size and distance to been pertormed oveL the past 35 years in snil to the structure, b) the mechanical properties of the

  2. Histological changes and wound healing response following noncontact holmium: YAG laser thermal keratoplasty.

    PubMed Central

    Koch, D D

    1996-01-01

    PURPOSE: To evaluate acute histological changes and the induced wound healing response in corneal tissue following noncontact holmium:YAG laser thermal keratoplasty (LTK). METHODS: LTK using 10 pulses and a range of radiant energies was performed on 3 human corneas one day prior ro their removal at penetrating keratoplasty. Rabbit corneas were treated with 10-pulse and 5-pulse LTK and followed for up to 3 months. Tissues were studies with light and transmission electron microscopy and immunohistochemistry. RESULTS: The amount of acute tissue injury increased with increasing pulse radiant energy. In human corneas, changes in the irradiated zones included epithelial cell injury and death loss of fine filamentous structure in Bowman's layer, disruption of stromal lamallae, and keratocyte injury and death. In the rabbit corneas, similar acute changes were noted. By 3 weeks, epithelial hyperplasia and stromal contraction were present. Wound healing in the rabbit corneas included repair of the epithelial attachment complex, keratocyte activation, synthesis of type I collagen, partial restoration of stromal keratan sulfate and type VI collagen, and retrocorneal membrane formation. Compared to 10-pulse treatments, 5-pulse treatments produced less acute tissue injury and had more rapid restoration of normal stromal architecture. CONCLUSION: Noncontact LTK produces acute epithelial and stromal tissue changes and in rabbit corneas stimulates a brisk wound healing response. These changes could contribute to postoperative regression of induced refractive correction. Further work is required to determine if reductions in the magnitude of acute tissue injury and induced wound healing response will enhance the efficacy and stability of LTK. Images FIGURE 1A FIGURE 1B FIGURE 2A FIGURE 2B FIGURE 3A FIGURE 3B FIGURE 4A FIGURE 4B FIGURE 4C FIGURE 4D FIGURE 5A FIGURE 5B FIGURE 5C FIGURE 5D FIGURE 6A FIGURE 6B FIGURE 6C FIGURE 6D FIGURE 7A FIGURE 7B FIGURE 8A FIGURE 8B FIGURE 8C FIGURE

  3. Tectonic lamellar keratoplasty with acellular corneal stroma in high-risk corneal transplantation.

    PubMed

    Li, Naiyang; Wang, Xiaoran; Wan, Pengxia; Huang, Minghai; Wu, Zheng; Liang, Xuanwei; Liu, Ying; Ge, Jian; Huang, Junqi; Wang, Zhichong

    2011-01-01

    Tectonic lamellar keratoplasty (TLKP) is a primary surgical procedure to improve the condition of the recipient bed in high-risk corneal transplantation. It is usually performed for a secondary optical penetrating keratoplasty (PKP). The present study was undertaken to explore a new strategy for TLKP using acellular corneal stroma (ACS) prepared by decellularization. ACS for TLKP was prepared from cat cornea by decellularization. The efficiency of the decellularization was examined by hematoxylin and eosin (H&E) staining and through DNA content analysis. Twenty-eight New Zealand white rabbits, as recipients, were assigned to one of two groups that had different material for their TLKP. The TLKP was combined with a central optical PKP as a single-stage procedure. Either ACS or fresh cat corneal lamella, 11.25 mm in diameter, was used for the TLKP in these two groups. After TLKP, a 6.5-mm full-thickness cat cornea was placed in the central cornea of each recipient rabbit for PKP. Clinical outcomes and the histology of the transplants were compared post-operatively. ACS for TLKP prolonged the survival of the transplants. The mean survival time of the transplants in the ACS group (36.4±4.3 days) was longer than for those in the control group (14.0±2.2 days, p<0.05). The ACS group showed a significantly smaller neovascularization area compared to the control group. The areas of corneal neovascularization were 5.3±1.1 mm² and 45.2±4.9 mm² (p<0.05), respectively, after two weeks, and 25.1±4.7 mm² and 105.3±12.4 mm² (p<0.05), respectively, after four weeks. Histology revealed that fewer inflammatory cells were infiltrating the transplants in the ACS group than those in the control group. The use of ACS for TLKP prolonged the survival of corneal transplants, reduced corneal neovascularization, and prevented from infiltration of inflammatory cells. It is a feasible and effective strategy to prolong the survival of transplants in high-risk corneal transplantation.

  4. Two-photon optical microscopy imaging of endothelial keratoplasty grafts.

    PubMed

    Lombardo, Marco; Parekh, Mohit; Serrao, Sebastiano; Ruzza, Alessandro; Ferrari, Stefano; Lombardo, Giuseppe

    2017-03-01

    To investigate the microstructure of endothelial keratoplasty grafts using two-photon optical microscopy. Six endothelial keratoplasty grafts obtained from human donor corneoscleral tissues and prepared by submerged hydrodissection technique were imaged by two-photon optical microscopy. In each graft, two liquid bubbles were created in order to investigate the presence of a conserved cleavage plane regardless of the volume of posterior stroma that remained attached to Descemet's membrane (DM); the first bubble (bubble A) was generated under DM and the second bubble (bubble B) injection was done in order to obtain a layer of deep stroma that kept the two bubbles separated. Six human donor corneoscleral tissues were used as controls. Second harmonic generation and two-photon emitted fluorescence signals were collected from each specimen. Dissection of stroma occurred along the posterior collagen lamellae at variable distance from DM, which ranged between 3 and 16 μm in bubble A and between 23 and 41 μm in bubble B. The residual stroma included, anteriorly, bands of collagen lamellae, and thin bundles of stromal collagen fibrils, posteriorly, which were tightly intertwining with the underlying DM. There was no anatomically distinct plane of separation between these pre-Descemetic stromal collagen bundles and the overlying collagen lamellae with this hydrodissection technique. Two-photon optical microscopy provided label-free high-resolution imaging of endothelial keratoplasty grafts, showing that the most posterior stroma changes organization at approximately 10 μm above the DM. The pre-Descemetic stromal collagen fibrils form an intertwined complex with DM, which cannot be separated using hydrodissection.

  5. Relaxing incision for control of postoperative astigmatism following keratoplasty.

    PubMed

    Troutman, R C; Swinger, C

    1980-02-01

    A new technique has been presented which provides a second surgical approach to correct excessive residual astigmatism following keratoplasty. The relaxing incision procedure has advantages over wedge resection in that it can be performed at the slit lamp, it gives no initial overcorrection, and it has a much shorter postoperative course while giving rapid results without suturing. Since this technique does not appear to produce significant hyperopia and may produce a tendency toward myopia, the corneal surgeon would thus have alternative techniques from which to choose, depending, in part, on the spherical component of the refraction.

  6. Intradescemetic air bubble trapping during deep anterior lamellar keratoplasty.

    PubMed

    Touboul, David; Binder, Perry S; Colin, Joseph

    2012-02-01

    We describe a case of a 52-year-old man in whom the appearance of an air bubble developed, trapped within the Descemet membrane (DM), that occurred during a planned deep anterior lamellar keratoplasty using the "big bubble" technique. This situation can occur because Descemet membrane's anatomic structure can be opened by the gas dissection; this complication may result in unanticipated results during and after this type of surgery. Surgeons should be aware of this specific risk, so they will recognize it when it occurs. Optical coherence tomography (OCT) imaging and surgical management are presented.

  7. Noncontact laser penetrating keratoplasty: in-vivo comparative evaluation in rabbit and cat

    NASA Astrophysics Data System (ADS)

    Parel, Jean-Marie A.; Jeffers, William Q.; Simon, Gabriel; Hostyn, Patrick; Legeais, Jean-Marc; Kuhne, Francois; Takesue, Yoshiko; Shimada, Hiroyuki; Barraquer, Elena; Loertscher, Hanspeter; Nowicky, M.; Ren, Qiushi; Nose, Izuru

    1993-06-01

    With their inherent precision and avoidance of tissue deformation, non-contact laser trephines may minimize graft postoperative astigmatism. Laser-cut corneal button geometry surpassed handheld and equaled Hanna and Krumeich vacuum held trephines, without significant endothelium or wound healing differences for linear cuts between laser and metal blades. To compare the laser with metal trephines, we performed 8 mm diameter grafts on 12 rabbits and 12 cats. A new laser system, using an advanced pulsed HF laser coupled to a computer controlled optical delivery system and equipped for quasi-instantaneous simultaneous 8-point corneal marking (200 ns) for precise suture placement at the 5.5 to 10.5 mm diameter and rapid corneal trephination (approximately equals 6 sec), or a new disposable sterile vacuum-assisted Hessburg-Barron (HB) trephine was used in each procedure. Circumferential keratotomies were more accurately and more easily performed with the laser. No statistical differences were found in wound strength and healing. The laser produced a slightly lower astigmatism. These initial results suggest the safety of HF laser corneal marking-trephination and its potential for PK procedures in humans.

  8. Penetrant-Indication-Measuring Compass

    NASA Technical Reports Server (NTRS)

    Schaefer, Lloyd

    1991-01-01

    Modified drafting compass well suited to measurement of length of crack or width of area stained by penetrant-dye-inspection method. Equipped with any of variety of standard curved or straight pointed tips. Modification consists in coating tips with dye that fluoresces light pink under same ultraviolet inspection light causing penetrant dye to fluoresce yellow green. Used in locations inaccessible to conventional fluorescent comparator. Eliminates errors of optical distortion in comparator, also eliminates errors of interpolation.

  9. Aspergillus Flavus Keratitis after Deep Anterior Lamellar Keratoplasty

    PubMed Central

    Jafarinasab, Mohammad-Reza; Feizi, Sepehr; Yazdizadeh, Forouzan; Rezaei Kanavi, Mozhgan; Moein, Hamid-Reza

    2012-01-01

    Purpose To report the clinical, microbiologic, confocal scan and histopathologic features of Aspergillus flavus keratitis which developed immediately after deep anterior lamellar keratoplasty (DALK). Case Report A 28-year-old woman underwent DALK using the big-bubble technique for keratoconus. The operation was uneventful, yielding a bare Descemet’s membrane (DM) followed by transplantation of a corneal graft devoid of DM and endothelium. Four days after keratoplasty, mild infiltrates were noticed in the inferonasal margin of the graft, which rapidly progressed to involve the adjacent recipient cornea. Confocal scan findings suggested filamentous fungal keratitis, leading to initiation of topical and systemic antifungal medications followed by immediate replacement of the graft. Histopathologic examination disclosed keratitis caused by a filamentous fungus, which was determined by microbiologic cultures to be Aspergillus flavus. Early diagnosis and appropriate management resulted in complete recovery from this potentially devastating infection. Conclusion Aspergillus Flavus can cause graft ulcers immediately after DALK. Confocal scan proved to be a valuable tool for early diagnosis and prompt intervention to control this otherwise devastating infection. PMID:23275826

  10. Partial lamellar keratoplasty for peripheral corneal disease using a graft from the glycerin-preserved corneoscleral rim.

    PubMed

    Gao, Hua; Wang, Xiuxian; Echegaray, Jose J; Li, Suxia; Wang, Ting; Shi, Weiyun

    2014-06-01

    To evaluate the feasibility of partial lamellar keratoplasty (LK) for treatment of peripheral corneal disease (PCD) using a graft from the corneoscleral rim preserved in glycerin. Patients who underwent LK for PCD at Shandong Eye Hospital from January 2006 to December 2012 were included. Corneoscleral rims of donor grafts, out of which the corneal buttons had been punched and used for penetrating keratoplasty, were preserved in glycerin and used for LK procedures. A trephine of 7.5-8.0 mm was used to mark the central cornea. An excision was made according to the size of the lesions, after which a partial ring-shaped corneoscleral graft was transplanted to repair the peripheral cornea. Visual acuity, refractive astigmatism, and complications were monitored. There were 26 patients (28 eyes), including 15 patients with Terrien's marginal degeneration, eight with Mooren's ulcer, two with Wegener's granulomatosis, and one with peripheral corneal ulcer. The mean follow-up was 15 months (range, 6-36 months). Uncorrected visual acuity was improved by a mean of 3.17 Snellen chart lines (P = 0.010), and best spectacle-corrected visual acuity was improved by a mean of 0.85 Snellen chart lines (P = 0.045) at 6 months after surgery. The refractive astigmatism decreased by 5.1 ± 8.6 diopters (P = 0.003). Two patients suffering graft ulcers (recurrence) were successfully treated by a second partial LK. No graft rejection occurred. Partial LK using a graft from the corneoscleral rim appears to be effective in the treatment of patients with PCD. This approach saves the donor graft, which is important in the countries or regions with scarcity of donor tissue.

  11. Microbubble incision as a new rescue technique for big-bubble deep anterior lamellar keratoplasty with failed bubble formation.

    PubMed

    Riss, Stephan; Heindl, Ludwig M; Bachmann, Björn O; Kruse, Friedrich E; Cursiefen, Claus

    2013-02-01

    To describe a new surgical technique allowing dissection down to Descemet membrane in big-bubble deep anterior lamellar keratoplasty (DALK) with failed big-bubble formation (the "microbubble incision technique"). This is an interventional case series of 10 consecutive patients with keratoconus undergoing intended big-bubble DALK with failure to establish a normal big bubble. In all patients, repeated air injections into the stroma were performed, leaving a whitish colored stroma. Lamellar dissection as far down as possible was then performed within this white tissue. As soon as the anterior chamber was visible, a large remaining intrastromal air bubble was incised with a sharp 15-degree knife introduced perpendicular to the tissue to open up this predescemetic bubble. If deeper air bubbles were still visible, this approach was repeated. Using a blunt spatula, this new layer was then prepared and viscodissection performed. Using this novel approach, in 9 of the 10 patients, it was possible to dissect down to Descemet membrane. Macroperforation made conversion to penetrating keratoplasty necessary in 1 patient. Microperforations not necessitating conversion occurred in 2 patients. All 9 patients with "rescued" DALK had an uneventful postoperative course and had a mean visual acuity of 20/63 ± 20/125 (range, 20/500-20/50) and a mean endothelial cell count of 1672 ± 163 cells per square millimeter (range, 1493-1867 cells/mm) at 3 months. Microbubble incision is a new rescue technique for big-bubble DALK patients without bubble formation allowing for a safer dissection down to Descemet membrane.

  12. Pachymetry-guided intrastromal air injection ("pachy-bubble") for deep anterior lamellar keratoplasty: results of the first 110 cases.

    PubMed

    Ghanem, Ramon C; Bogoni, Ayla; Ghanem, Vinícius C

    2015-06-01

    To report intraoperative and 1-year postoperative results of the pachy-bubble technique for deep anterior lamellar keratoplasty (DALK). This prospective interventional case series included 110 eyes of 107 patients with anterior corneal pathology who underwent DALK, including 78 with keratoconus. Outcome measures included the rate of bubble formation, rate of completing DALK, bubble types, complications, and visual and keratometric parameters. Intrastromal air injection was attempted in 109 eyes, and the air bubble was achieved in 93 eyes (85.3%). Intrastromal 2% methylcellulose injection was attempted in 9 eyes, after unsuccessful air bubble formation, and the viscobubble was achieved in 7 eyes (77.8%). Manual layer-by-layer dissection was performed in 8 eyes. Bubble formation was reached in 100 eyes (90.9%). Overall, 105 eyes (95.5%) achieved DALK. Air bubble occurred as type 1 (white margin) in 96.6% of the cases and as type 2 (clear margin) in 3.4%. There was a statistically significant improvement in all visual and keratometric parameters analyzed. Macroperforations converted to penetrating keratoplasty occurred in 5 eyes (4.5%) and microperforations in 12 (10.9%). There were significantly higher rates of perforation when a bubble was not achieved (P = 0.018) and when it was achieved as type 2 (P = 0.033). Interface haze occurred in 5 eyes (4.5%) and stromal rejection in 11 (10.0%). A short learning curve was observed for air bubble formation. Bubble formation, especially type 1, is the key to decrease the risk of perforation in DALK. The pachy-bubble was safe, effective, and reproducible in promoting DALK with air bubble and viscobubble formation with a short learning curve.

  13. Ultrastructural analysis of the decellularized cornea after interlamellar keratoplasty and microkeratome-assisted anterior lamellar keratoplasty in a rabbit model

    PubMed Central

    Hashimoto, Yoshihide; Hattori, Shinya; Sasaki, Shuji; Honda, Takako; Kimura, Tsuyoshi; Funamoto, Seiichi; Kobayashi, Hisatoshi; Kishida, Akio

    2016-01-01

    The decellularized cornea has received considerable attention for use as an artificial cornea. The decellularized cornea is free from cellular components and other immunogens, but maintains the integrity of the extracellular matrix. However, the ultrastructure of the decellularized cornea has yet to be demonstrated in detail. We investigated the influence of high hydrostatic pressure (HHP) on the decellularization of the corneal ultrastructure and its involvement in transparency, and assessed the in vivo behaviour of the decellularized cornea using two animal transplantation models, in relation to remodelling of collagen fibrils. Decellularized corneas were prepared by the HHP method. The decellularized corneas were executed by haematoxylin and eosin and Masson’s trichrome staining to demonstrate the complete removal of corneal cells. Transmission electron microscopy revealed that the ultrastructure of the decellularized cornea prepared by the HHP method was better maintained than that of the decellularized cornea prepared by the detergent method. The decellularized cornea after interlamellar keratoplasty and microkeratome-assisted anterior lamellar keratoplasty using a rabbit model was stable and remained transparent without ultrastructural alterations. We conclude that the superior properties of the decellularized cornea prepared by the HHP method were attributed to the preservation of the corneal ultrastructure. PMID:27291975

  14. Femtosecond Laser Assisted Deep Anterior Lamellar Keratoplasty Outcomes and Healing Patterns Compared to Manual Technique

    PubMed Central

    Alio, Jorge L.; Abdelghany, Ahmed A.; Barraquer, Rafael; Hammouda, Laila M.; Sabry, Ahmed M.

    2015-01-01

    The purpose of the study is to report the visual, refractive, and wound healing pattern outcomes of femtosecond assisted deep anterior lamellar keratoplasty (DALK) compared to the conventional manual technique. DALK was performed on 50 eyes of 47 advanced keratoconus patients. The patients were divided into two groups, 25 eyes each, depending on whether femtosecond assisted or manual DALK technique was performed for the side cut of the procedure only. Patients were followed up at 1 month, 6 months, and 1 year for visual acuity, clinical refraction, corneal cylinder, date of suture removal, and side cut corneal healing pattern according to new grading classification of the side cut scar (Grade 0 = transparent scar, 1 = faint healing opacity, 2 = evident healing opacity, 3 = significant opacity with some cosmetic imbalance, and 4 = highly significant opacity with very significant cosmetic imbalance). Outcomes are reported at one year. In conclusion, femtosecond assisted and manual DALK show comparable visual and refractive outcomes but femtosecond assisted DALK shows more evident corneal wound healing patterns at the side cut. This observation may indicate that an activated cornea wound healing might allow earlier suture removal when femtosecond technology is used to perform the side cut for DALK. PMID:26557663

  15. Changes in Corneal Densitometry in Patients with Fuchs Endothelial Dystrophy after Endothelial Keratoplasty.

    PubMed

    Alnawaiseh, Maged; Rosentreter, André; Prokosch, Verena; Eveslage, Maria; Eter, Nicole; Zumhagen, Lars

    2017-02-01

    The aim of the study was to quantify corneal densitometry in patients with Fuchs endothelial dystrophy (FED) after endothelial keratoplasty. We retrospectively reviewed the charts and anterior segment data of patients with FED before and after endothelial keratoplasty. Patients were examined using the Scheimpflug-based Oculus Pentacam corneal densitometry module. Densitometry parameters in different corneal layers and in different annuli were extracted and analyzed. 27 eyes of 27 patients after endothelial keratoplasty (11 DSAEK, 16 DMEK) were included. After endothelial keratoplasty the total corneal light backscatter at total corneal thickness in the central cornea (0-2 mm annulus) was significantly lower than before (DSAEK: p = 0.026, DMEK: p = 0.001). In the entire group the total corneal light backscatter at total corneal thickness and at total diameter before surgery correlated with the postoperative values (Pearson correlation = 0.49, p = 0.01). The strongest correlation was found in the central layer in the DMEK group (Pearson correlation = 0.79, p < 0.001). Corneal densitometry is a useful, objective method for quantification of the outcome of posterior lamellar keratoplasty irrespective of visual acuity. There is a significant correlation between preoperative and postoperative corneal light backscatter values after endothelial keratoplasty, especially in the case of the DMEK procedure.

  16. A Biodegradable, Sustained-Released, Prednisolone Acetate Microfilm Drug Delivery System Effectively Prolongs Corneal Allograft Survival in the Rat Keratoplasty Model

    PubMed Central

    Liu, Yu-Chi; Peng, Yan; Lwin, Nyein Chan; Venkatraman, Subbu S.

    2013-01-01

    Frequent and long-term use of topical corticosteroids after corneal transplantation is necessary to prevent graft rejection. However, it relies heavily on patient compliance, and sustained therapeutic drug levels are often not achieved with administration of topical eye drops. A biodegradable drug delivery system with a controlled and sustained drug release may circumvent these limitations. In this study, we investigated the efficacy of a prednisolone acetate (PA)-loaded poly (d,l-lactide-co-ε-caprolactone) (PLC) microfilm drug delivery system on promoting the survival of allogeneic grafts after penetrating keratoplasty (PK) using a rat model. The drug release profiles of the microfilms were characterized (group 1). Subsequently, forty-eight PK were performed in four experimental groups: syngeneic control grafts (group 2), allogeneic control grafts (group 3), allogeneic grafts with subconjunctivally-implanted PA microfilm (group 4), and allogeneic grafts with PA eye drops (group 5; n = 12 in each). PA-loaded microfilm achieved a sustained and steady release at a rate of 0.006–0.009 mg/day, with a consistent aqueous drug concentration of 207–209 ng/ml. The mean survival days was >28 days in group 2, 9.9±0.8 days in group 3, 26.8±2.7 days in group 4, and 26.4±3.4 days in group 5 (P = 0.023 and P = 0.027 compared with group 3). Statistically significant decrease in CD4+, CD163+, CD 25+, and CD54+ cell infiltration was observed in group 4 and group 5 compared with group 3 (P<0.001). There was no significant difference in the mean survival and immunohistochemical analysis between group 4 and group 5. These results showed that sustained PA-loaded microfilm effectively prolongs corneal allograft survival. It is as effective as conventional PA eye drops, providing a promising clinically applicable alternative for patients undergoing corneal transplantation. PMID:23940573

  17. Descemet's Stripping Automated Endothelial Keratoplasty Tissue Insertion Devices

    PubMed Central

    Khan, Salman Nasir; Shiakolas, Panos S.; Mootha, Venkateswara Vinod

    2015-01-01

    This review study provides information regarding the construction, design, and use of six commercially available endothelial allograft insertion devices applied for Descemet's stripping automated endothelial keratoplasty (DSAEK). We also highlight issues being faced in DSAEK and discuss the methods through which medical devices such as corneal inserters may alleviate these issues. Inserter selection is of high importance in the DSAEK procedure since overcoming the learning curve associated with the use of an insertion device is a time and energy consuming process. In the present review, allograft insertion devices were compared in terms of design, construction material, insertion technique, dimensions, incision requirements and endothelial cell loss to show their relative merits and capabilities based on available data in the literature. Moreover, the advantages/disadvantages of various insertion devices used for allograft insertion in DSAEK are reviewed and compared. The information presented in this review can be utilized for better selection of an insertion device for DSAEK. PMID:27051492

  18. Use of indocyanine green in deep lamellar endothelial keratoplasty.

    PubMed

    John, Thomas

    2003-03-01

    A new technique using indocyanine green (ICG) during deep lamellar endothelial keratoplasty (DLEK) to stain the corneal stroma of the donor disk facilitated surgical placement of the disk in the host corneal opening created to match the donor disk. Two female patients, aged 82 and 77 years, had ICG staining of the donor corneal disk during DLEK for pseudophakic bullous keratopathy and Fuchs' corneal dystrophy. By 24 hours postoperatively, no ICG was detected clinically by biomicroscopy of the sutureless (no corneal sutures) lamellar transplanted corneas. This is the first report of the use of ICG during DLEK and the first intrastromal use of ICG in the human cornea. The use of ICG facilitated the DLEK procedure and appears to be safe for intraoperative use in the cornea.

  19. [Emergency Keratoplasty with Porcine Xenografts in Necrotizing Keratitis].

    PubMed

    Drozhzhyna, Galyna I; Gaidamaka, Tetiana B; Cursiefen, Claus; Bachmann, Björn O; Ivanovska, Olena V; Ostashevsky, Viktor L; Kogan, Boris M; Usov, Volodymyr J; Pasyechnikova, Natalija V

    2017-07-06

    Background The great shortage of donor material in Ukraine makes it necessary to find additional sources of transplant material. A possible suitable material are the porcine corneas, as they are similar in structure and biomechanical parameters to the human cornea. The purpose of our study was to analyze the results of therapeutic keratoplasty (KP) with keratoxenotransplants from cryolyophilized porcine corneas in patients with severe necrotizing keratitis. Methods A retrospective analysis of 32 xenotransplantations patients with severe necrotizing keratitis (17 lamellar, 6 stepped perforating, 4 perforating, 5 "biological coverage" according to Puchkovskaya) was completed. Results All eyes could be preserved, but the graft was rejected in all eyes. A semitransparent xenograft (XG) was achieved in 9 patients (33.3%). The best results were obtained after lamellar XKP with an XT diameter of 3.5 - 6.5 mm. Lamellar XTs with larger diameters (7.0 - 10.0 mm) were opaque. Postoperatively, the intensity of the inflammatory response after stepped XKP was slightly lower than that of the classical perforating XKP. A new KP with human corneas had to be performed in 5 patients, in one case combined with an antiglaucomatous operation and in another case with cataract extraction. Antiglaucomatous surgery had to be performed in 5 patients (15.6%). Conclusion In the absence of human donor corneas, a porcine keratoxenoimplant can be used as temporary therapeutic keratoplasty in case of emergency stop the inflammation process and to save the eye. In cases of keratoxenoimplant, a poor visual outcome is expected. Georg Thieme Verlag KG Stuttgart · New York.

  20. Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device compared to keratoplasty for the treatment of corneal ectasia.

    PubMed

    DeLoss, Karen S; Fatteh, Nadeem H; Hood, Christopher T

    2014-11-01

    To compare the ocular characteristics and visual outcomes of eyes with corneal ectasia that were fitted with the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral device to those that underwent keratoplasty. Retrospective, comparative case series. We reviewed the charts of consecutive patients with corneal ectasia that were evaluated for PROSE or underwent keratoplasty at our institution. Clinical data, topographic indices, and corneal thickness were reviewed, and eyes were stratified according to the Amsler-Krumeich classification for severity of ectasia. Only the more severe eye of each patient was included in the study. We compared visual acuity before and after PROSE fitting or keratoplasty. For PROSE evaluations, achievement of satisfactory fit and continued wear at 1 year of follow-up were recorded. From 2010 to 2012, 36 patients underwent PROSE evaluation for corneal ectasia while 37 patients underwent keratoplasty for the same indication. All eyes were successfully fitted with the PROSE device. Eyes in the keratoplasty group had more severe ectasia than eyes in the PROSE group (P = .038). Visual acuity was achieved more rapidly in the PROSE cohort compared to keratoplasty, and mean visual acuity was significantly better for all eyes (P < .0001) and when including only eyes with stage 4 ectasia (P < .001). More eyes with stage 4 ectasia achieved 20/25 visual acuity after PROSE than after keratoplasty (P = .003). At 1 year follow-up in the PROSE cohort, Snellen acuity was 20/28 (P = .108 vs keratoplasty), improving to 20/25 with over-refraction (P = .006 vs keratoplasty). Eyes with advanced corneal ectasia can be successfully fitted with the PROSE device, and the visual acuity outcome for stage 4 ectasia was better and more rapid compared to keratoplasty. The acuity remained excellent with 1 year of follow-up. PROSE evaluation should be considered in patients with advanced corneal ectasia before proceeding to keratoplasty, especially if

  1. Outcomes after Descemet stripping endothelial keratoplasty in glaucoma patients with previous trabeculectomy and tube shunt implantation.

    PubMed

    Wiaux, Christophe; Baghdasaryan, Elmira; Lee, Olivia L; Bourges, Jean-Louis; Deng, Sophie X; Yu, Fei; Aldave, Anthony J

    2011-12-01

    To describe the incidence of intraoperative and postoperative complications and visual outcomes in eyes with previous penetrating glaucoma surgery undergoing Descemet stripping endothelial keratoplasty (DSEK). A retrospective review of the first 227 cases of DSEK performed by 2 surgeons at a single institution. Data were collected regarding the performance of concurrent ocular procedures, intraoperative complications, postoperative visual outcomes, and postoperative complications, including primary graft failure, donor dislocation, endothelial rejection, and intraocular pressure (IOP) elevation. Fifty-six of the 227 DSEK procedures were performed in 52 eyes with previous trabeculectomy and/or tube shunt implantation. The percentage of procedures performed in eyes with and without a history of penetrating glaucoma surgery that resulted in primary graft failure (5.4% vs. 4.1%; P = 0.71) and donor dislocation (12.5% vs. 15.2%; P = 0.83) were not statistically significantly different. Additionally, the endothelial rejection rate was not significantly different between cases performed in eyes with (1/19.2 eye-years) and without (1/20.1 eye-years) a history of glaucoma surgery (P = 0.99). The incidence of elevated IOP (≥ 25 mm Hg) after DSEK was the highest in eyes with medically controlled glaucoma (47.4%), followed by eyes without a history of glaucoma (18.3%), and was the lowest in eyes with previous glaucoma surgery (11.5%). Postoperative corrected distance visual acuity was improved over the preoperative corrected distance visual acuity in 81%, 95%, and 88% of eyes with previous glaucoma surgery, medically controlled glaucoma, and no glaucoma, respectively. DSEK is an effective procedure to improve vision in the majority of eyes with advanced glaucoma after trabeculectomy and/or tube shunt implantation. The incidence of postoperative complications, such as donor dislocation, primary graft failure, and endothelial rejection, is not significantly higher in eyes with

  2. 'Blue bubble' technique: an ab interno approach for Descemet separation in deep anterior lamellar keratoplasty using trypan blue stained viscoelastic device.

    PubMed

    Livny, Eitan; Bahar, Irit; Hammel, Naama; Nahum, Yoav

    2017-07-03

    In this study, we examined a novel variant of 'big-bubble' deep anterior lamellar keratoplasty using trypan-blue-stained viscoelastic device for the creation of a pre-descemetic bubble. Ten corneoscleral rims were mounted on an artificial anterior chamber (AC). The AC was filled with air through a limbal paracentesis. A Melles' triangulated spatula was inserted through the paracentesis, with its tip penetrating the AC, was then slightly retracted and pushed into the deep stroma above the roof of the paracentesis. A mixture of trypan blue and viscoelastic device (Healon, Abbott Medical Optics, Abbott Park, Illinois) was injected into this intra-stromal pocket using a 27-G cannula to create a pre-descemetic separation bubble. Bubble type and visualization of dyed viscoelastic device were noted. The method was later employed in three cases. In all 10 corneoscleral rims, the technique successfully created a visible pre-descemetic (type 1) bubble that could be expanded up to the predicted diameter of trephination. Subsequent trephination and the removal of corneal stroma were uneventful. In two out of four clinical cases, a type 1 bubble was created, while in two others, visco-dissection failed and dyed viscoelastic was seen in the AC. The presented technique holds promise of being a relatively easy to perform, predictable and well-controlled alternative for achieving a type 1 bubble during deep anterior lamellar keratoplasty surgery. The trypan-blue-stained viscoelastic device facilitates proper visualization and control of the separation bubble and assists in identifying the penetrance to the separation bubble prior to removal of the stromal cap. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

  3. [The artificial epithelium in chronic corneal diseases and to avoid emergency keratoplasty (author's transl)].

    PubMed

    Turss, R; Retzlaff, K; Hebrock, R

    1979-02-01

    Report on the treatment of 41 patients in the last 10 years. In chronic corneal diseases epikeratoprosthesis is possible when every other therapy failed. With growing experience functional results are better and complications seldom. Since several years we use glued-on contact lenses in acute ulcers too in order to avoid emergency keratoplasty. When suitable donor material is missing or if plastic surgery of the eye lids is necessary the artificial epithelium prevents ulcer perforation as a mechanical collagenase inhibitor. The anterior chamber can be reinstalled in perforated ulcers by sealing with cyanoacrylate glue and covering with artificial epithelium. A corticosteroid therapy of the iritis becomes possible to avoid the frequent complication of anterior synechia in later keratoplasty. By reducing the steroid dosis vascularisation of the ulcer is reached and a corneal grafting can be evaded sometimes if the prognosis of keratoplasty is poor or the central cornea is clear such as in ulcers near the limbus.

  4. Effects of a novel push-through technique using the implantable collamer lens injector system for graft delivery during endothelial keratoplasty.

    PubMed

    Kang, Sug Jae; Kim, Myung Hun; Kim, Mee Kum; Wee, Won Ryang; Lee, Jin Hak; Chung, Eui Sang

    2013-04-01

    To investigate effects of a new push-through insertion method for donor lenticules using an injector system on endothelial viability ex vivo and in a clinical case series of endothelial keratoplasty. An ex vivo delivery model was used with porcine corneoscleral rims. We compared the endothelial viability in a new push-through insertion method using the Visian Implantable Collamer Lens (ICL) injector versus that of standard forceps-assisted insertion for lenticule delivery. Twenty porcine corneal lenticules were divided into four groups by insertion method and wound size. Vital dye staining was performed and devitalized areas were semi-quantitatively assessed by digital imaging. In the clinical case series, Descemet's stripping endothelial keratoplasty (DSEK) using the push-through method was performed in seven patients and endothelial outcome was determined six months postoperatively. Mean devitalized areas for the push-through method were significantly lower than for forceps-assisted insertion through 3.2 mm incision (23.99 ± 2.17% vs. 50.48 ± 5.07%, p = 0.009) in the ex vivo model. Average endothelial cell counts of donor tissues of patients who underwent DSEK were 26.4% lower six months postoperatively. Push-through delivery of donor lenticules using the Visian ICL injector system appears to be less harmful to endothelial cells than conventional forceps-assisted delivery.

  5. Treatment of acanthamoeba keratitis with intravenous pentamidine before therapeutic keratoplasty.

    PubMed

    Sacher, Bradley A; Wagoner, Michael D; Goins, Kenneth M; Sutphin, John E; Greiner, Mark A; Kitzmann, Anna S

    2015-01-01

    The aim of this study was to evaluate the outcome of pretreatment of Acanthamoeba keratitis with intravenous pentamidine (IVP) before therapeutic keratoplasty (TKP). A retrospective chart review was performed of the medical records of every patient treated with IVP before TKP for Acanthamoeba keratitis at a single, tertiary care eye center between January 1, 2002, and December 31, 2012. The main outcome measures were microbiological cure, graft survival, and visual outcome. Eight eyes of 7 patients met the inclusion criteria. Preoperatively, all 8 eyes had failed traditional antiamoebic therapy, including 5 eyes with recurrent infections after previous TKP. The patients were treated with IVP (190-400 mg/d) for a median of 14 days (range, 7-26 days). After 8 TKP, a microbiological cure was achieved, and a clear graft was maintained in 5 (62.5%) eyes during a mean follow-up interval of 31.2 months (range, 1.0-95.7 months). Repeat TKP in 3 eyes with recurrent Acanthamoeba keratitis resulted in 2 additional microbiological cures and 1 more clear graft. The final best-corrected visual acuity was ≥20/40 in 5 (62.5%) eyes and worse than 20/200 in 3 eyes. Overall, the final vision was improved in 6 (75.0%) eyes, remained the same in 1 (12.5%) eye, and was worse in 1 (12.5%) eye. The adjunctive use of IVP before TKP may assist with the achievement of microbiological cure, clear graft, and good visual outcome in a majority of eyes with Acanthamoeba keratitis.

  6. Use of Brilliant Blue G in Descemet's Membrane Endothelial Keratoplasty

    PubMed Central

    Yuda, Kentaro; Oyakawa, Itaru; Kato, Naoko

    2017-01-01

    Vital staining of the endothelial graft is essential during Descemet's membrane endothelial keratoplasty (DMEK) to ensure surgical success. DMEK surgeons worldwide commonly use trypan blue (TB) to this end. However, TB may exert toxic effects on both the cornea and retina. Recently, Brilliant Blue G (BBG) has become recognized as an alternative stain for use during vitreoretinal surgery; BBG is associated with lower levels of toxicity. We retrospectively analyzed the utility of BBG staining during DMEK. We used 0.1% (w/v) BBG to stain the DMEK grafts of 12 patients. We evaluated the best spectacle-corrected visual acuity (BSCVA), central corneal thickness (CCT), and endothelial cell density (ECD) before and 3 and 6 months after surgery. BBG was effective in terms of graft visualization during DMEK. The BSCVA (log  MAR) improved from 0.99 ± 0.57 to 0.01 ± 0.07 (p < 0.05). The CCT decreased from 720.3 ± 58.1 μm preoperatively to 511.5 ± 50.6 μm at 6 months postoperatively (p = 0.0001). The ECD decreased from 2,754 ± 296 cells/mm2 to 1,708 ± 426 cells/mm2 at 6 months postoperatively (p < 0.001). The ECD loss was 37.9 ± 16.3%. The outcomes using BBG were comparable to those of earlier reports that employed TB; thus, BBG may be a viable alternative to TB. PMID:28676862

  7. OPTICS OF CONDUCTIVE KERATOPLASTY: IMPLICATIONS FOR PRESBYOPIA MANAGEMENT

    PubMed Central

    Hersh, Peter S

    2005-01-01

    Purpose To define the corneal optics of conductive keratoplasty (CK) and assess the clinical implications for hyperopia and presbyopia management. Methods Four analyses were done. (1) Multifocal effects: In a prospective study of CK, uncorrected visual acuity (UCVA) for a given refractive error in 72 postoperative eyes was compared to control eyes. (2) Surgically induced astigmatism (SIA): 203 eyes were analyzed for magnitude and axis of SIA. (3) Higher-order optical aberrations: Corneal higher-order optical aberrations were assessed for 36 eyes after CK and a similar patient population after hyperopic laser in situ keratomileusis (LASIK). (4) Presbyopia clinical trial: Visual acuity, refractive result, and patient questionnaires were analyzed for 150 subjects in a prospective, multicenter clinical trial of presbyopia management with CK. Results (1) 63% and 82% of eyes after CK had better UCVA at distance and near, respectively, than controls. (2) The mean SIA was 0.23 diopter (D) steepening at 175° (P < .001); mean magnitude was 0.66 D (SD, 0.43 D). (3) After CK, composite fourth- and sixth-order spherical aberration increased; change in (Z12) spherical aberration alone was not statistically significant. When compared to hyperopic LASIK, there was a statistically significant increase in composite fourth- and sixth-order spherical aberration (P < .01) and spherical aberration (Z12) alone (P < .02); spherical aberration change was more prolate after CK. (4) After the CK monovision procedure, 80% of patients had J3 or better binocular UCVA at near; 84% of patients were satisfied. Satisfaction was associated with near UCVA of J3 or better in the monovision eye (P = .001) and subjectively good postoperative depth perception (P = .038). Conclusions CK seems to produce functional corneal multifocality with definable introduction of SIA and higher-order optical aberrations, and development of a more prolate corneal contour. These optical factors may militate toward

  8. Deep anterior lamellar keratoplasty for pellucid marginal degeneration***

    PubMed Central

    Al-Torbak, Abdullah A.

    2012-01-01

    Purpose To present the surgical outcomes of deep anterior lamellar keratoplasty (DALK) for pellucid marginal degeneration (PMD). Methods A retrospective review was performed in 16 eyes of 16 patients who underwent DALK at the King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia between January 1, 2006 and December 30, 2009. Baring of Descemet’s membrane (DM) during DALK was achieved in 8 (50%) eyes; residual stroma was left intraoperatively in the remaining 8 (50%) eyes. The big bubble technique was performed in 10 (62.5%) eyes and manual dissection was performed in the remaining 6 (37.5%) eyes. Visual acuity (LogMAR notation), intraocular pressure, intraoperative complications and postoperative graft status were assessed. Results The mean follow up was 14.6 ± 8.2 months (range 6–35 months). The mean overall age was 31.4 ± 9.6 years (range, 19–50 years). Visual acuity increased statistically significantly from 0.9 ± 0.3 (range 0.5–1.6) preoperatively to 0.4 ± 0.2 (range 0.0–0.7) at last follow-up (p < 0.0001). There was a statistically significant improvement in postoperative sphere, cylinder, and spherical equivalent (p < 0.035, p < 0.001, and p < 0.02, respectively) compared to preoperative. Postoperative visual acuity was not statistically significantly related to gender, type of surgical technique, and baring or perforation of DM. The main graft-related complication was graft–host vascularization (2/16 eyes). Conclusion DALK reduces severe corneal astigmatism and results in good visual and refractive outcomes and is an effective alternative for patients with PMD. PMID:23964180

  9. Intraocular Lens Calcifications After (Triple-) Descemet Membrane Endothelial Keratoplasty.

    PubMed

    Schrittenlocher, Silvia; Penier, Marius; Schaub, Friederike; Bock, Felix; Cursiefen, Claus; Bachmann, Björn

    2017-07-01

    To identify incidence of and risk factors for calcifications of intraocular lenses (IOLs) after Descemet membrane endothelial keratoplasty (DMEK). Retrospective cohort study. Retrospective review of charts and slit-lamp images of 564 consecutive patients from the prospective Cologne DMEK database who underwent DMEK in pseudophakic eyes or DMEK in combination with cataract surgery (triple-DMEK) between September 3, 2013 and October 30, 2015 at the Department of Ophthalmology, University of Cologne. IOL calcifications after (triple-)DMEK occurred in 14 patients (2.5%). Visual acuities in affected and unaffected eyes were 0.33 ± 0.24 logMAR and 0.16 ± 0.01 logMAR after 3 months (P < .001) as well as 0.28 ± 0.16 logMAR and 0.13 ± 0.08 logMAR (P < .001) after 6 months, respectively. The proportions of triple-DMEK vs DMEK, the use of SF6 gas vs room air for anterior chamber tamponade, and the presence of hydrophilic vs hydrophobic acrylic IOLs were comparable in affected and unaffected eyes. Patients with IOL calcifications had higher rebubbling rates than patients without. Larger pupil diameters at the time of surgery showed a tendency to slightly larger areas of IOL calcifications. IOL calcifications after anterior chamber gas tamponade in DMEK lead to visual impairment and are associated with the number of rebubblings after DMEK. IOL calcifications also occur in hydrophobic acrylic IOLs. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Evidence of endothelial cell migration after descemet membrane endothelial keratoplasty.

    PubMed

    Jacobi, Christina; Zhivov, Andrey; Korbmacher, Judit; Falke, Karen; Guthoff, Rudolf; Schlötzer-Schrehardt, Ursula; Cursiefen, Claus; Kruse, Friedrich E

    2011-10-01

    To investigate the hypothesis that adult corneal endothelial cells can migrate after Descemet membrane endothelial keratoplasty (DMEK). Prospective observational study. Five patients with Fuchs endothelial dystrophy were examined 1 year after uneventful DMEK. These patients had been selected on the basis of slightly decentered grafts and/or large descemetorrhexis showing areas of denuded corneal stroma, which were covered by neither the patients' Descemet membrane (DM) nor the graft. These areas were investigated by in vivo confocal laser scanning microscopy using a specially designed Heidelberg Retina Tomograph II and Rostock cornea module equipped with custom-made software. Source data (frame rate 30 Hz, 384 × 384 pixels, 400 × 400 μm) were used to create large-scale maps of the scanned area in automatic real-time composite mode. In each case an on-line mapping with maximum size up to 3.2 × 3.2 mm (3072 × 3072 pixels) was performed. Corneal stroma overlying areas devoid of DM was transparent. In vivo confocal laser scanning microscopy of stroma devoid of DM revealed a monolayer of endothelial cells in all patients observed. The morphologic pattern of these cells was similar to that of endothelial cells on DM grafts but different from the morphology of the patients' own endothelium, suggesting migration of donor endothelial cells from DMEK grafts. The results strongly support the hypothesis that adult corneal endothelial cells are able to migrate in the human eye. Furthermore, we provide evidence to support the hypothesis that grafted endothelium migrates onto the host tissue, repopulating the corneal stroma with a regular endothelial phenotype. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Graft epithelial defects after deep anterior lamellar keratoplasty.

    PubMed

    Feizi, Sepehr; Javadi, Fatemeh; Javadi, Mohammad Ali

    2014-11-01

    The aim of this study was to report the incidence of epithelial defects and identify donor factors that might correlate with the presence of epithelial defects and graft reepithelialization time after a deep anterior lamellar keratoplasty (DALK). In this retrospective study, 283 consecutive keratoconic eyes underwent DALK using donor corneas of different qualities, ranging from fair to excellent. The donor data included age and sex, cause of death, death-to-preservation time, preservation-to-surgery time, epithelial and stromal status, endothelial cell density and morphology, and graft rating. On the first postoperative day, the corneal surface was carefully examined before and after the application of fluorescein stain, and the patients were followed up daily until complete reepithelialization occurred. A multivariate regression analysis was used to assess the correlation between donor characteristics and graft epithelial defects on postoperative day 1. The mean donor and recipient ages were 33.5 ± 13.2 and 27.6 ± 7.9 years, respectively. Two hundred sixty-four (93.3%) grafts had epithelial defects on day 1. The epithelial defects completely healed after 3.5 ± 2.7 (range, 1-37) days. In the univariate analysis, the presence of epithelial defects on postoperative day 1 had a significant correlation with donor preservation-to-surgery time (P = 0.01), epithelial sloughing (P < 0.001), and graft rating (P = 0.004). In the multivariate analysis, only donor epithelial sloughing significantly influenced the presence of epithelial defects on postoperative day 1 (odds ratio = 9.26, P < 0.001). Graft epithelial defects were very common after DALK. The epithelial status of donors was the only independent factor predictive of the surface integrity on the first postoperative day.

  12. Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty During the Surgeon Learning Curve Versus Descemet Stripping Endothelial Keratoplasty Performed at the Same Time

    PubMed Central

    Rose-Nussbaumer, Jennifer; Alloju, Shashi; Chamberlain, Winston

    2016-01-01

    Purpose To compare outcomes after Descemet Membrane Endothelial Keratoplasty (DMEK) and traditional Descemet Stripping Endothelial Keratoplasty (DSEK) during the surgeon’s DMEK learning curve in a prospective, non-randomized, consecutive, interventional case series. Methods Consecutive patients presenting to the university eye clinics and undergoing endothelial keratoplasty were included. Data including patient demographics, visual acuity, endothelial cell counts and complications were recorded at baseline, as well as 3 and 6 months post-operatively. The primary outcome for this study was BSCVA at 6 months. Pre-specified secondary outcomes included endothelial cell counts and complication rates. Results A total of 60 eyes of 42 consecutive patients met inclusion criteria, underwent endothelial keratoplasty, and were included in this analysis. Of these, 18 eyes of 14 patients had DSEK while 42 eyes of 28 patients had DMEK. After controlling for baseline visual acuity, study participants undergoing DMEK had a statistically significant approximately half-line improvement in visual acuity compared with DSEK at 3 months (P=0.05) but not at 6 months (P=0.22). DMEK patients experienced an average of 43% endothelial cell loss compared with 25% in DSEK. There were 5 primary graft failures after DMEK compared with 0 after DSEK and but this was not a statistically significant difference (P=0.09). Conclusion During the surgeon’s DMEK learning curve there was some evidence of improved visual acuity outcomes in DMEK. We observed worse 6-month endothelial cell loss among DMEK patients; however this may improve with surgeon experience. PMID:28018708

  13. Does Corneal Collagen Cross-linking Reduce the Need for Keratoplasties in Patients With Keratoconus?

    PubMed

    Sandvik, Gunhild Falleth; Thorsrud, Andreas; Råen, Marianne; Østern, Atle E; Sæthre, Marit; Drolsum, Liv

    2015-09-01

    To investigate whether the introduction of corneal collagen cross-linking (CXL) influences the frequency of keratoplasties in patients with keratoconus. Data were obtained from a cohort of patients from our corneal transplant registry. Two different periods were compared, 2005 to 2006 (period 1) and 2013 to 2014 (period 2). Patients during period 1 had surgery before the introduction of CXL treatment, and patients in period 2 had surgery after this treatment was well established in our department. Age and gender were registered, and the Amsler-Krumeich classification system was applied to grade the degree of keratoconus. The total number of keratoplasties performed during period 1 was 137, and keratoconus was the cause of surgery in 55 eyes (55 patients). The corresponding numbers in period 2 were 231 and 26 eyes (26 patients), respectively. The difference in the number of keratoplasties for keratoconus in both periods was statistically significant (P = 0.003). There were no significant differences in the distributions of age and gender between both periods. In period 1, 63.6% of the eyes were graded as stage 4 in the Amsler-Krumeich classification, compared with 96.2% in period 2 (P = 0.001). The frequency of keratoplasty for keratoconus has been more than halved in our department over the last decade. There is reason to believe that this reduction is for a great part caused by the introduction of CXL treatment.

  14. Modification of Siepser sliding suture technique for iris repair and endothelial keratoplasty.

    PubMed

    Schoenberg, Evan D; Price, Francis W

    2014-05-01

    We describe a technique for closed-chamber iris repair that prevents knot and suture tail exposure into the anterior chamber. This modification of the Siepser sliding slipknot suture technique is particularly important in the setting of combined or future endothelial keratoplasty to prevent mechanical damage to donor endothelium during transplantation. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  15. [Regression analysis of idiopathic endothelial cell loss after perforating normal risk keratoplasty: basic principles for long-term analysis of endothelial risk factors in a retrospective clinical study].

    PubMed

    Böhringer, D; Reinhard, T; Godehardt, E; Sundmacher, R

    2001-06-01

    For the characterisation of influencing factors on chronic endothelial cell loss after penetrating keratoplasty by means of multivariate statistics, a mathematical description of the course of the individual postoperative endothelial cell density is a prerequisite. This mathematical description should result in a standardized index value describing course and amount of the postoperative endothelial cell loss over time in a canonical way. The slopes of the linear regression lines for each individual scatter plot of a) the endothelial cell density values plotted against the respective postoperative time directly (linear regression), and b) after logarithmic transformation (exponential regression) are evaluated, respectively. 58 patients after normal-risk keratoplasty (26x keratokonus, 22x Fuchs-dystrophy and 10 cases of corneal decompensation after cataract surgery) with 5 or more postoperatively acquired endothelial density values and without any episodes of graft rejection were included in this study. Mean follow up was 2.9 +/- 1.1 years. The postoperative endothelial cell density values were plotted against the respective time for each patient individually. The coefficients of variation (R2) derived from the linear and the exponential regression models were calculated for each of these scatter plots. The pairs of R2 values (linear vs. exponential) were compared statistically. A dependence of the difference of linear and exponential R2-values on the ophthalmologic diagnosis was tested as well. The linear model is able to declare 83% the total variance of the course of the endothelial cell density. The exponential model even declares 86%. This small difference was statistically significant. Since both methods of regression describe the course of the cell density well, intra/and extrapolation of missing endothelial values is possible with both models. No dependence of the difference of linear and exponential R2-values on the ophthalmologic diagnosis could be

  16. Penetration of concrete targets

    SciTech Connect

    Forrestal, M.J.; Cargile, J.D.; Tzou, R.D.Y.

    1993-08-01

    We developed penetration equations for ogive-nosed projectiles that penetrated concrete targets after normal impact. Our penetration equations predict axial force on the projectile nose, rigid-body motion, and final penetration depth. For target constitutive models, we conducted triaxial material experiments to confining pressures of 600 MPa and curve-fit these data with a linear pressure-volumetric strain relation and with a linear Mohr-Coulomb, shear strength-pressure relation. To verify our penetration equations, we conducted eleven penetration experiments with 0.90 kg, 26.9-mm-diameter, ogive-nosed projectiles into 1.37-m-diameter concrete targets with unconfined compressive strengths between 32-40 MPa. Predictions from our penetration equation are compared with final penetration depth measurements for striking velocities between 280--800 m/s.

  17. Outcomes of Air Injection Within 2 mm Inside a Deep Trephination for Deep Anterior Lamellar Keratoplasty in Eyes With Keratoconus.

    PubMed

    Busin, Massimo; Scorcia, Vincenzo; Leon, Pia; Nahum, Yoav

    2016-04-01

    To evaluate the outcomes of a new technique for deep anterior lamellar keratoplasty (DALK) employing the injection of air up to 2 mm inside a deep trephination (intended within 100 μm from the endothelial surface) obtained with a guarded trephine set by means of anterior segment optical coherence tomography (AS OCT). Retrospective, noncomparative, interventional case series. The success rate and learning curve of pneumatic dissection in one clinical practice were analyzed in nonscarred keratoconic eyes undergoing a standardized DALK including 9-mm trephination intended to a depth within 100 μm from the endothelial surface, based on the thinnest AS OCT measurement at this site; and injection of air through a cannula advanced 1-2 mm centripetally from the bottom of the trephination. Surgical parameters, success rate of pneumatic dissection, and complications were recorded. Eighty-eight eyes of 88 patients were included in the study. Pneumatic dissection succeeded in 75 of 88 eyes (85%). No significant correlation could be found between number of cases performed and success rate for this surgeon. Complications included loss of suction during trephination (n = 2, 2.3%) and perforation (n = 4, 4.6%). Conversion to penetrating keratoplasty was necessary in 1 case (1.1%). Setting an adjustable trephine to a depth within 100 μm from the endothelial surface eliminates the need for reaching the central cornea for successful pneumatic dissection and substantially flattens the learning curve of DALK, while achieving a constant success rate above 80% and minimizing complications. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Modified lamellar keratoplasties for the treatment of deep stromal abscesses in horses.

    PubMed

    McMullen, Richard J; Gilger, Brian C; Michau, Tammy M

    2015-09-01

    To describe a surgical modification of deep lamellar endothelial keratoplasty (DLEK) and posterior lamellar keratoplasty (PLK) procedures, to facilitate surgery on standing horses under-sedation. Four client-owned horses, for which the owners declined surgery under general anesthesia, underwent standing corneal lamellar keratoplasty procedures for the treatment of deep corneal stromal abscesses. All four horses were placed in stocks and sedated with detomidine. Local eyelid and retrobulbar blocks were performed to provide local analgesia and akinesia, and each horse's head was stabilized and supported by soft pads placed on a mobile cart. Deep lamellar endothelial keratoplasties (DLEKs) and posterior lamellar keratoplasties (PLKs) were performed on two horses each, for the treatment of deep stromal abscesses (DSA). Following the first DLEK, a mid-stromal two-step anterior lamellar keratectomy modification was used to facilitate rapid closure of the anterior chamber immediately following removal of the abscess. Each of the four horses had similar cosmetic and postoperative visual outcomes, compared to previously published results. Intra-operative complications were most prevalent in the first DLEK case (i.e., focal iris and lens damage and postoperative anterior chamber collapse) and were all but eliminated in the remaining three cases. Similar to previously reported findings, greater postoperative corneal fibrosis was observed in the DLEK cases. In horses with deep stromal or endothelial abscesses, for which general anesthesia is not an option, both the modified DLEK and PLK corneal procedures may be performed as an alternative to enucleation on the standing, sedated horse. © 2014 American College of Veterinary Ophthalmologists.

  19. FAA fluorescent penetrant activities

    SciTech Connect

    Moore, D.G.; Larson, B.F.

    1997-11-01

    The Federal Aviation Administration`s Airworthiness Assurance NDI Validation Center (AANC) and the Center for Aviation Systems Reliability (CASR) are currently working to develop a liquid penetrant inspection (LPI) system evaluation capability that will support the needs of the penetrant manufacturers, commercial airline industry and the FAA. The main focus of this facility is to support the evaluation of penetrant inspection materials, penetrant systems and to apply resources to support industry needs. This paper discusses efforts to create such a facility and an initial project to produce fatigue crack specimens for evaluation of Type 1 penetrant sensitivities.

  20. Instantaneous Conventions

    PubMed Central

    Misyak, Jennifer; Noguchi, Takao; Chater, Nick

    2016-01-01

    Humans can communicate even with few existing conventions in common (e.g., when they lack a shared language). We explored what makes this phenomenon possible with a nonlinguistic experimental task requiring participants to coordinate toward a common goal. We observed participants creating new communicative conventions using the most minimal possible signals. These conventions, furthermore, changed on a trial-by-trial basis in response to shared environmental and task constraints. Strikingly, as a result, signals of the same form successfully conveyed contradictory messages from trial to trial. Such behavior is evidence for the involvement of what we term joint inference, in which social interactants spontaneously infer the most sensible communicative convention in light of the common ground between them. Joint inference may help to elucidate how communicative conventions emerge instantaneously and how they are modified and reshaped into the elaborate systems of conventions involved in human communication, including natural languages. PMID:27793986

  1. [Fourier analysis as a mathematical model for evaluating and presenting postoperative corneal topography data after non-mechanical perforating keratoplasty].

    PubMed

    Langenbucher, A; Seitz, B; Kus, M M; Steffen, P; Naumann, G O

    1997-04-01

    Videokeratography has given the possibility to obtain information in curvature from a much larger region of the cornea than that covered by keratometry. Fourier analysis as a mathematical model can be used to represent real physical attributes of the cornea and to divide corneal topography in its basic components: the zero-frequency component as the mean ring power, the one-cycle component as a representation of decentration and the two-cycle component as a representation of regular corneal toricity. The purpose of this study was the reconstruction of the corneal refraction after penetrating keratoplasty with a small number of characteristic parameters and the evaluation of the time course of the fourier coefficients as indices for a regular astigmatic cornea in the postkeratoplasty period including suture removal. Fourty patients (group 1: 20 primary dystrophies, group 2: 20 keratoconus) underwent nonmechanical trephination (excimer laser MEL60, Aesculap-Meditec, Heroldsberg, Germany) in penetrating keratoplasty. All procedures (7.5 mm in dystrophies, 8.0 mm in keratoconus, 8 orientation teeth, double-running 10-0 nylon suture) were performed by one surgeon. At a postoperative gate of 6 weeks, 6 months, before partial suture removal and after complete suture removal, corneal topography (TMS1, Tomey, Tennenlohe, Germany), keratometry, visual acuity and subjective refraction were assessed. Radial approximation with a 5th order polynomial fit of the refractive data on 25 non-centric rings of the TMS, within 256 hemimeridians was performed to get data at equally spaced concentric rings. Fast Fourier transformation of the data sets in the mid periphery (1.4-1.8 mm apical distance) was done to get DC-, one-cycle and two-cycle component. Fourier coefficients were correlated with keratometric readings, subjective refractive values and visual acuity. Spherical equivalent was fairly constant in the postoperative interval before suture removal. After suture removal, a

  2. Chemical penetration enhancers.

    PubMed

    Newton, Stephen J

    2013-01-01

    Chemical penetration enhancers are utilized in topical preparations as a method for enhancing permeation of drugs across the skin. In particular, they are utilized for transdermal delivery of medications in an attempt to produce a systemic response, to avoid first-pass metabolism, and to decrease the gastrointestinal transit time observed with oral medications. A review of the selection of chemical penetration enhancers, their mechanism of action, the most common chemical penetration enhancers in each class, and alternatives will be discussed in detail.

  3. Tectonic Deep Anterior Lamellar Keratoplasty in Impending Corneal Perforation Using Cryopreserved Cornea

    PubMed Central

    Jang, Ji Hye

    2011-01-01

    We report a case of tectonic corneal transplantation for impending corneal perforation to preserve anatomic integrity using cryopreserved donor tissue. An 82-year-old woman exhibiting impending corneal perforation suffered from moderate ocular pain in the left eye for one week. After abnormal tissues around the impending perforation area were carefully peeled away using a Crescent blade and Vannas scissors, the patient received tectonic deep anterior lamellar keratoplasty using a cryopreserved cornea stored in Optisol GS® solution at -70℃ for four weeks. At six months after surgery, the cornea remained transparent and restored the normal corneal thickness. There were no complications such as corneal haze or scars, graft rejection, recurrent corneal ulcer, and postoperative rise of intraocular pressure. Cryopreserved donor lamellar tissue is an effective substitute in emergency tectonic lamellar keratoplasty, such as impending corneal perforation and severe necrotic corneal keratitis. PMID:21461227

  4. Development of a new superficial punch for Descemet's Membrane Endothelial Keratoplasty donor tissue preparation.

    PubMed

    Ruzza, Alessandro; Parekh, Mohit; Salvalaio, Gianni; Ferrari, Stefano; Ponzin, Diego

    2016-04-01

    Endothelial Keratoplasty (EK) is a corneal surgical procedure that allows a selective transplantation of the posterior layer of the cornea. Descemet's Membrane Endothelial Keratoplasty (DMEK) is one of the EK procedures in which the diseased Descemet's Membrane and the endothelium are replaced with a healthy donor tissue. To achieve this, the donor cornea is cut superficially from the endothelial side and the tissue can be separated using specific instruments like Pierse Notched, Acute or Fogla forceps. However, the pressure required to punch the superficial layer has always been a challenge and therefore a calibrated device to punch and excise the required superficial layer has been designed. This new model of punch will help to identify the peripheral edge of the DMEK lenticule which in turn helps to excise the tissue exclusively, further reducing the donor tissue wastage, as seen with the current tissue preparation methods.

  5. [Spatial contrast sensitivity in patients with high myopia after refraction lamellar keratoplasty].

    PubMed

    Shpak, A A; Medvedev, I V; Karamian, A A; Milova, S V

    1997-01-01

    Spatial contrast sensitivity (SCS) is one of the most important visual functions. SCS was examined in 23 patients (38 eyes) with high myopia before and after refraction lamellar keratoplasty (RLK) and in 21 healthy controls. Before surgery an appreciable (p < 0.01) reduction of SCS was observed in patients with high myopia in the entire range of spatial frequencies in comparison with the controls. After the operation the maximally corrected vision acuity was virtually unchanged, whereas the parameters of SCS somewhat increased for all frequencies, the increase being statistically reliable at frequencies of 0.23 to 3.75 and 15 cycles/degree. Hence, the studies demonstrated that changes in the topography of the cornea after refraction lamellar keratoplasty do not deteriorate the visual function.

  6. Simultaneous bilensectomy and endothelial keratoplasty for angle-supported phakic intraocular lens-induced corneal decompensation

    PubMed Central

    Mittal, Vikas; Mittal, Ruchi; Singh, Daljit

    2011-01-01

    A 40-year-old lady presented with severe endothelial cell loss in both eyes 14 years after angle-supported phakic intraocular lens (AS PIOL) implantation. The left eye had severe corneal edema with bullous keratopathy. The right eye had markedly reduced endothelial cell count (655 cells/mm2) although the cornea was clear. She underwent simultaneous bilensectomy (AS PIOL explantation and phacoemulsification) and Descemet's stripping and endothelial keratoplasty (DSEK) in the left eye. Explanted AS PIOL was identified as ZSAL-4 (Morcher, Stuttgart, Germany) model. Corneal edema cleared completely in 2 months with a best corrected visual acuity (-2.25 D sph) of 20/60. No intervention was done in the right eye. The present case illustrates that AS PIOL-induced endothelial decompensation can be effectively managed by simultaneous bilensectomy and endothelial keratoplasty. PMID:21666321

  7. Tectonic deep anterior lamellar keratoplasty in impending corneal perforation using cryopreserved cornea.

    PubMed

    Jang, Ji Hye; Chang, Sung Dong

    2011-04-01

    We report a case of tectonic corneal transplantation for impending corneal perforation to preserve anatomic integrity using cryopreserved donor tissue. An 82-year-old woman exhibiting impending corneal perforation suffered from moderate ocular pain in the left eye for one week. After abnormal tissues around the impending perforation area were carefully peeled away using a Crescent blade and Vannas scissors, the patient received tectonic deep anterior lamellar keratoplasty using a cryopreserved cornea stored in Optisol GS® solution at -70℃ for four weeks. At six months after surgery, the cornea remained transparent and restored the normal corneal thickness. There were no complications such as corneal haze or scars, graft rejection, recurrent corneal ulcer, and postoperative rise of intraocular pressure. Cryopreserved donor lamellar tissue is an effective substitute in emergency tectonic lamellar keratoplasty, such as impending corneal perforation and severe necrotic corneal keratitis.

  8. Confocal microscopy of corneal wound healing after deep lamellar keratoplasty in rabbits.

    PubMed

    Abdelkader, Almamoun; Elewah, El-Sayed M; Kaufman, Herbert E

    2010-01-01

    To compare wound healing and morphologic characteristics of the host-donor interface in rabbit corneas after maximum-depth and near-Descemet membrane anterior lamellar keratoplasty. Descriptive analysis of confocal microscopy images after 2 types of deep lamellar keratoplasty (deep stromal dissection vs total stromal resection). Deep anterior lamellar keratoplasty (DALK) was performed in 16 rabbit eyes, with exposure of the Descemet membrane in 8 eyes (deep group) and deep stromal dissection to near the Descemet membrane in 8 eyes (near group). A full-thickness graft devoid of endothelium and Descemet membrane was sutured in place. Confocal examination of lamellar interface and wound edge was performed throughout 6 months. Four days postoperatively, confocal microscopy revealed numerous highly reflective keratocytes at and adjacent to the interface in all eyes, fewer in the deep than the near group. Keratocyte density and reflectivity returned to normal at 4 to 6 weeks (deep) and 8 to 10 weeks (near) postoperatively. In the deep group, the smooth interface showed less scarring. In the near group, stroma-to-stroma healing stimulated more activated keratocytes and hence more haze. Successful DALK requires minimal central healing for clarity but significant suture-stimulated healing at the edge to prevent corneal bulge. Deep anterior lamellar keratoplasty is rarely accompanied by rejection, avoids entrance into the anterior chamber, and can be performed with tissue that does not have living keratocytes. Interface healing is a determinant of the final visual acuity; depth of the lamellar bed is a major determinant of the healing response. Although dissection to bare the Descemet membrane is more difficult, there is less keratocyte activation and scarring.

  9. Manual suction versus femtosecond laser trephination for penetrating keratoplasty: intraocular pressure, endothelial cell damage, incision geometry, and wound healing responses.

    PubMed

    Angunawela, Romesh I; Riau, Andri; Chaurasia, Shyam S; Tan, Donald T; Mehta, Jodhbir S

    2012-05-04

    To measure real-time intraocular pressure (IOP) during trephination with a manual suction trephine (MST) and the femtosecond laser (FSL), and to assess endothelial cell damage, incision geometry, and wound healing response with these procedures. IOP was monitored with an intracameral sensor. Eight rabbits underwent manual suction trephination. Eight rabbits had FSL trephination (FSL-T). Slit lamp photography, confocal microscopy, and anterior segment optical coherence tomography (AS-OCT) were performed at baseline and postoperatively. Animals were sacrificed at 4 hours and 3 days. Tissue was examined with scanning electron microscopy (SEM) and immunohistochemistry for an array of wound-healing markers. Separately, 6 human corneas had MST (3) and FSL-T (3). Incision geometry was imaged with high resolution Optovue AS-OCT. The average IOP during MST and FSL-T was similar (37 mm Hg). There was wider IOP fluctuation during the MST cutting phase (60 mm Hg maximum). There were 1-2 rows of endothelial loss on either side of the incision for FSL-T and 2-5 rows deep for MST. Immune cell responses at 4 hours (CD11b) were comparable, greater apoptosis with FSL-T (TUNEL) occurred at 4 hours, and there was increased keratocyte proliferation at 3 days (Ki67) with FSL-T. There was significantly greater undercutting of the cornea with MST (46.86 degrees versus 16.72 degrees). There is more IOP variation during MST. Average IOP is 37 mm Hg for both techniques. More endothelial damage and undercutting of the cornea occurs with MST. The wound healing response to FSL-T appears greater at 3 days.

  10. Penetration Testing of the OPRA Regolith Penetrator

    NASA Astrophysics Data System (ADS)

    El Shafie, A.; Kegege, O.; Barrows, S.; Roe, L.; Ulrich, R.

    2008-03-01

    Our work focuses on the mechanical design and penetration forces for the Optical Probe for Regolith Analysis. This is a spike-shaped probe delivered to a planet, asteroid, or cometary body by a lander to provide IR spectroscopy of the subsurface.

  11. The Effect of High Intensity Focused Ultrasound Keratoplasty on Rabbit Anterior Segment

    PubMed Central

    Li, Meixuan; Yan, Pisong; Luo, Qiang; Zhang, Yu

    2017-01-01

    Purpose. To evaluate the safety of high-intensity focused ultrasound keratoplasty as a treatment for presbyopia by examining its effect on the rabbit anterior segment. Methods. The right corneas of 36 New Zealand rabbits were treated with HIFU keratoplasty. The animals were sacrificed at 1, 7, 15, 30, 60, and 90 days after operation. Collagen type I, MMP-2, and MMP-9 were evaluated using immunohistochemistry. For the detection of apoptosis, the TUNEL method was applied. The SOD and MDA levels were analyzed with assay kits. Results. Collagen type I, MMP-2, and MMP-9 levels were altered after the operation but returned to normal within 90 days. The apoptotic index (AI) of the corneal cells decreased from 1 to 30 days gradually. No apoptosis was observed in the epithelial cells of the lens, and the SOD and MDA levels were normal at any time point. Conclusion. After HIFU keratoplasty, the histomorphology of the cornea changed, the corneal collagen type I levels decreased, the corneal MMP-2 and MMP-9 levels increased, and the corneal cells underwent apoptosis for a period of time. Ninety days after the operation, the levels returned to normal, and the lenses were not affected. Thus, HIFU presents good biological safety for eyes. PMID:28280636

  12. Endothelial Keratoplasty Safety-Basket Suture for Management of Difficult Cases.

    PubMed

    Behshad, Soroosh; Jacobsen, Bradley H; Pinney, Elizabeth; Wade, Mathew; Garg, Sumit Sam

    2016-06-01

    To describe a novel technique of a safety-basket for management of Descemet stripping automated endothelial keratoplasty in eyes with defects of the lens-iris diaphragm, postvitrectomized eyes, eyes with previous glaucoma tube-shunt or trabeculectomy, or when the patient cannot lie supine. The safety-basket suture is placed after the endothelial graft has been positioned under air and all wounds have been closed. Double-armed 10-0 polypropylene suture on a curved needle is passed under the graft in a single-running fashion, a modification of the Masket technique used as a safety suture in the management of malpositioned intraocular lenses. Care is taken not to touch the graft with the needle or suture. The suture can be left in place and removed at the slit-lamp postoperatively with continued use of topical antibiotics while the safety-basket is left in place. The technique was used successfully for 35 high-risk cases with good success with no cases of postoperative infection. Endothelial keratoplasty safety-basket sutures, when used in high-risk Descemet stripping automated endothelial keratoplasty patients with abnormal anterior segment anatomy can provide support to maintain the graft in a central position and thus allow for easier rebubbling, should it detach in the early postoperative course.

  13. Collagen crosslinking for ectasia following PRK performed in excimer laser-assisted keratoplasty for keratoconus.

    PubMed

    Spadea, Leopoldo

    2012-01-01

    To report the results of corneal collagen crosslinking (CXL) in a patient with corneal ectasia developed after excimer laser-assisted lamellar keratoplasty for keratoconus and a secondary photorefractive keratectomy (PRK) for residual refractive error. A 33-year-old woman, who had originally been treated for keratoconus in the right eye by excimer laser-assisted lamellar keratoplasty, subsequently had her residual ametropia treated by topographically guided, transepithelial excimer laser PRK. Five years after PRK, the patient developed corneal ectasia showing concomitant visual changes of best spectacle-corrected visual acuity (BSCVA) reduced to 20/33 with a refraction of -6.00 +6.00 × 30. The minimum corneal thickness at the ectasia apex was 406 µm. A treatment of riboflavin-UVA-induced corneal CXL was performed on the right eye. Two years after the CXL treatment, the right eye improved to 20/20 BSCVA with a refraction of plano +1.00 × 50 while exhibiting a clear lamellar graft. Corneal CXL provided safe and effective management of ectasia developed after excimer laser-assisted lamellar keratoplasty and PRK.

  14. Descemet membrane endothelial keratoplasty (DMEK) early stage graft failure in eyes with preexisting glaucoma.

    PubMed

    Treder, Maximilian; Alnawaiseh, Maged; Eter, Nicole

    2017-07-01

    To evaluate the effect of a preexisting glaucoma on the early postoperative outcome of a descemet membrane endothelial keratoplasty (DMEK). All patients who underwent DMEK surgery at the Department of Ophthalmology of the University of Muenster with a follow-up of at least 3 months (90d) were included in this study. The best corrected distance visual acuity (BCDVA), the intraocular pressure (IOD), the rate of re-keratoplasty and the rebubbling rate were inter alia recorded. The results of patients with (group 1) and without a preexisting glaucoma (group 2) were compared. 74 eyes of 59 patients with a mean follow-up of 152 ± 70 days were included. 65 eyes were in group 1 and 9 eyes in group 2. The BCDVA significantly improved in both groups after surgery (p < 0.03). The Re-keratoplasty rate (p = 0.172), the number of rebubblings per patient (p = 0.571) and the rebubbling rate (p = 0.939) were not significantly different in patients without glaucoma compared to patients with a preexisting glaucoma. In the early stage outcome of DMEK no significant impact of a preexisting glaucoma was found.

  15. Follicular penetration and targeting.

    PubMed

    Lademann, Jürgen; Otberg, Nina; Jacobi, Ute; Hoffman, Robert M; Blume-Peytavi, Ulrike

    2005-12-01

    In the past, intercellular penetration was assumed to be the most important penetration pathway of topically applied substances. First hints that follicular penetration needs to be taken into consideration were confirmed by recent investigations, presented during the workshop "Follicular Penetration and Targeting" at the 4th Intercontinental Meeting of Hair Research Societies", in Berlin 2004. Hair follicles represent an efficient reservoir for the penetration of topically applied substances with subsequent targeting of distinct cell populations, e.g., nestin-expressing follicular bulge cells. The volume of this reservoir can be determined by differential stripping technology. The follicular penetration processes are significantly influenced by the state of the follicular infundibulum; recent experimental investigations could demonstrate that it is essential to distinguish between open and closed hair follicles. Topically applied substances can only penetrate into open hair follicle. Knowledge of follicular penetration is of high clinical relevance for functional targeting of distinct follicular regions. Human hair follicles show a hair-cycle-dependent variation of the dense neuronal and vascular network. Moreover, during hair follicle cycling with initiation of anagen, newly formed vessels occur. Thus, the potential of nestin-expressing hair follicle stem cells to form neurons and blood vessels was investigated.

  16. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  17. Thermomechanics of Impact & Penetration

    DTIC Science & Technology

    2005-09-30

    metallic projectiles into granular targets, at high striking velocities, formulate appropriate constitutive models , and solve selected problems by...constitutive models (preliminary work only) * Multiscale Numerical Simulations (preliminary work) PROGRESS Time-Dependent Penetration Path of...theory. A dislocation based plasticity model was also developed for the impact and penetration analysis. Numerical solutions were presented for selected

  18. Study of oligotrophic bog by ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Klokov, A. V.; Zapasnoy, A. S.; Miron'chev, A. S.; Dyukarev, E. A.; Smirnov, S. V.; Shipilova, S. S.

    2017-08-01

    The work deals with study of peat deposits of oligotrophic bog and spatial distribution of snow cover by geolocation. Data from ground penetrating radar were compared with the data of conventional measurements of a peat depth and snow cover. A fairly good agreement between the thickness of the peat deposits, snow depth by using ground penetrating radar and the data of conventional measurements has been obtained.

  19. Hermetic optical fiber penetrators for aquatic environments

    NASA Astrophysics Data System (ADS)

    Burke, Gregory C.

    1992-12-01

    The primary purpose of fiber optic penetrators is to provide a safe and reliable optical path through a hermetic barrier. The penetrators must resist pressure, humidity, corrosion, and maintain optical and mechanical integrity. Many optical fiber penetrators are manufactured from a combination of epoxies and application of a physical pressure seal onto the fiber. While providing a short term solution, epoxy lacks long term hermetic protection. Physical force applied to the fiber from a pressure seal may affect the refractive index of the optical cladding in soft and hard clad silica fibers. This presentation describes methods to provide a positive hermetic seal to a variety of optical fibers. These penetrators do not use lenses, prisms, or other conventional optical relay systems. Penetrators are intrinsically radiation hard and offer the convenience of providing a standard connector interface on one or both sides of the device. Examples of aquatic and high vacuum penetrators are presented. Application for this technology spans fiber geometry from single mode to large core step index fibers. Uses include communications and high energy transmission. This technology also is applicable to fiber based sensors.

  20. Advanced Penetrator Materials

    DTIC Science & Technology

    2007-11-02

    development • Uranium (U-V-X) Alloys • Alternative Matrix (adiabatic shearing) Tungsten Composites • Amorphous and Nanocrystalline Alloys • Severe Deformation...WIDER CHANNEL • MUSHROOM NOSE • LESS DEPTH • REMAINS SHARP • NARROW CHANNEL • DEEPER CAVITY TUNGSTEN HEAVY ALLOY U-3/4 Ti ALLOY U-8Mo ALLOYW-Ni-Fe...martensite (from Staker)(from Staker) • U-V alloys have the potential to maintain penetration capability while reducing penetrator density and mass. Tungsten

  1. [Perforating keratoplasty in endogenous eczema. An indication for systemic cyclosporin A--a retrospective study of 18 patients].

    PubMed

    Reinhard, T; Sundmacher, R

    1992-09-01

    Endogenous eczema represents a considerable risk for perforating keratoplasty because of the associated chronic surface disorders and complex immunological disturbances. Between December 1986 through October 1991 we performed 24 perforating keratoplasties in 20 eyes of 18 patients with endogenous eczema suffering from keratokonus, atopic keratokonjunctivitis and bullous keratopathy after intracapsular cataract extraction. During the follow-up period of 16 (3-48) months 6 transplants failed mostly due to surface problems as well as immune reactions and bacterial transplant infections. Systemically administered ciclosporin A was found to eliminate many of the previously unsolved problems. In summary, 18 out of 20 eyes achieved an improved visual acuity with clear transplants.

  2. Femtosecond laser assisted design of sutureless intrastromal graft as an alternative to partial thickness keratoplasty

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Durkee, Heather; Pini, Roberto; Canovetti, Annalisa; Malandrini, Alex; Lenzetti, Ivo; Rubino, Pierangela; Leaci, Rosachiara; Neri, Alberto; Scaroni, Patrizia; Menabuoni, Luca; Macaluso, Claudio

    2014-02-01

    Minimally invasive laser assisted surgery in ophthalmology is continuously developing in order to find new surgical approaches, preserve patient tissue and improve surgical results in terms of cut precision, restoration of visual acuity, and invasiveness. In order to achieve these goals, the current approach in corneal transplant is lamellar keratoplasty, where only the anterior or posterior part of the patient's cornea is substituted depending on the lesion or pathology. In this work, we present a novel alternative approach: a case study of intrastromal sutureless transplant, where a portion of the anterior stroma of a donor cornea was inserted into the stroma of the recipient cornea, aiming to restore the correct thickness of the patient's cornea. The patient cornea was paracentrally thin, as the result of a trophic ulcer due to ocular pemphigoid. A discoid corneal graft from the anterior stroma of a donor eye was prepared: a femtosecond laser cut with a trapezoidal profile (thickness was 300 μm, minor and major basis were 3.00 and 3.50 mm, respectively). In the recipient eye, an intrastromal cut was also performed with the femtosecond laser using a specifically designed mask; the cut position was 275 μm in depth. The graft was loaded into an injector and inserted as an intrastromal presbyopic implant. The postoperative analysis evidenced a clear and stable graft that selectively restored corneal thickness in the thinned area. Intrastromal corneal transplant surgery is a minimally invasive alternative to anterior or posterior lamellar keratoplasty in select cases. We believe that Sutureless Intrastromal Laser Keratoplasty (SILK) could open up new avenues in the field of corneal transplantation by fully utilizing the potential and precision of existing lasers.

  3. Outcomes of Descemet Stripping Endothelial Keratoplasty Using Eye Bank-Prepared Preloaded Grafts.

    PubMed

    Palioura, Sotiria; Colby, Kathryn

    2017-01-01

    To evaluate the feasibility of Descemet stripping endothelial keratoplasty using grafts preloaded by an eye bank in a commercially available insertion device. In this retrospective case series, a series of 35 eyes in 34 consecutive patients who underwent Descemet stripping endothelial keratoplasty for Fuchs endothelial dystrophy or previously failed full-thickness grafts at a single tertiary care center from March 2013 to March 2014 was included. The donor tissue had undergone pre-lamellar dissection, trephination, and loading into EndoGlide Ultrathin inserters at the Lions Eye Institute for Transplant and Research (Tampa, FL) and was shipped overnight in Optisol GS to the surgeon (K.C.). Surgery was performed within 24 hours from tissue preparation and loading by the eye bank. Donor and recipient characteristics, endothelial cell density (ECD), best-corrected visual acuity, and central corneal thickness were recorded. The main outcome measures were intraoperative and postoperative complications and ECD loss at 3, 6, and 12 months. One primary graft failure (2.8%), 2 rebubblings (5.7%), and 1 graft rejection (2.8%) occurred. Mean preoperative donor ECD was 2821 ± 199 cells/mm. Six months postoperatively, the mean endothelial cell loss was 25.3% ± 17.2% (n = 32), which remained stable at 1 year (31.5% ± 17.9%, n = 32). Mean best-corrected visual acuity improved from 20/100 preoperatively to 20/25 at a mean follow-up of 1 year (n = 32). Mean central corneal thickness was reduced from 711 ± 110 μm to 638 ± 66 μm at the last follow-up visit. Donor graft tissue preloaded by an eye bank can be used successfully for endothelial keratoplasty. Preloading reduces intraoperative tissue manipulation.

  4. Femtosecond and excimer laser-assisted endothelial keratoplasty (FELEK): a new technique of endothelial transplantation.

    PubMed

    Trinh, L; Saubaméa, B; Auclin, F; Denoyer, A; Lai-Kuen, R; El Hamdaoui, M; Labbé, A; Despiau, M-C; Brignole-Baudouin, F; Baudouin, C

    2014-03-01

    To describe a new technique of endothelial keratoplasty (EK) that improves the quality of lamellar dissection of donor cornea. We compared four techniques of donor cornea preparation for lamellar dissection on 8 donor corneas: mechanical dissection with a microkeratome, a single femtosecond laser lamellar cut, a double femtosecond laser lamellar cut and combined femtosecond laser lamellar dissection with excimer laser surface photoablation. The quality of the donor cornea interface was assessed and compared using scanning electron microscopy (SEM), and the most satisfactory technique was employed for EK on three patients. The postoperative anatomic results were analyzed with anterior segment spectral-domain optical coherence tomography (SD-OCT) and in vivo confocal microscopy (IVCM). The smoothest stromal interface was observed on SEM with the combined use of femtosecond laser dissection and excimer photoablation. The surgical procedures performed with donor cornea prepared by a combination of femtosecond and excimer lasers resulted in clear corneas after 1 month. SD-OCT showed good attachment of the endothelial graft and a hyperreflective interface. On IVCM, subepithelial haze, honeycomb-like activated keratocytes and needle-shaped particles were visible in the recipient corneal stroma as well as numerous hyperreflective particles on the donor-recipient interface. A new technique, femtosecond and excimer laser-assisted endothelial keratoplasty (FELEK), which refines the current limitations observed in Descemet-stripping automated endothelial keratoplasty (DSAEK), is described. Femtosecond laser dissection provides a thin and reproducible endothelial graft cut with a high level of safety and accuracy, while excimer photoablation yields a smooth, high-quality interface. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  5. Incidence and Outcomes of Positive Donor Corneoscleral Rim Fungal Cultures after Keratoplasty.

    PubMed

    Vislisel, Jesse M; Goins, Kenneth M; Wagoner, Michael D; Schmidt, Gregory A; Aldrich, Benjamin T; Skeie, Jessica M; Reed, Cynthia R; Zimmerman, M Bridget; Greiner, Mark A

    2017-01-01

    To determine the incidence of positive corneoscleral donor rim fungal cultures after keratoplasty and to report clinical outcomes of grafts with culture-positive donor rims. Retrospective cohort study. Consecutive donor corneas and keratoplasty recipients at a single tertiary referral center over 20 years. Patient charts were reviewed to determine the incidence of positive donor rim fungal cultures and clinical outcomes of all grafts using contaminated tissue. The primary outcome measures were positive donor rim fungal culture results and the development of postkeratoplasty fungal infection using corresponding corneal tissue. The secondary outcome measure was the impact of postoperative prophylaxis on donor tissue-associated infections. A total of 3414 keratoplasty cases were included in the statistical analysis. Seventy-one cases (2.1%) were associated with a fungal culture-positive donor rim. Candida species were cultured in 40 cases (56.3%). There was a higher incidence of positive rim cultures over the last 5 years of the analytic period compared with the first 15 years (P = 0.018). Fungal keratitis developed in 4 cases (5.6%), and all patients required further surgical intervention to achieve cure. There were no cases of fungal endophthalmitis. Empiric antimycotic prophylaxis initiated at the time of positive culture result reduced the incidence of keratitis from 15.8% in untreated cases to 1.9% in treated cases (P = 0.056). Positive donor rim fungal cultures are uncommon, but carry an unacceptably high risk of postoperative fungal infection. This risk may be reduced with prophylactic antimycotic therapy when culture-positive donor rims are identified. Copyright © 2016 American Academy of Ophthalmology. All rights reserved.

  6. Sequential selective same-day suture removal in the management of post-keratoplasty astigmatism

    PubMed Central

    Fares, U; Mokashi, A A; Elalfy, M S; Dua, H S

    2013-01-01

    Aims In a previous study, we proposed that corneal topography performed 30–40 min after the initial suture removal can identify the next set of sutures requiring removal, for the treatment of post-keratoplasty astigmatism. The aim of this study was to evaluate the effect of removing subsequent sets of sutures at the same sitting. Methods 10/0 nylon interrupted sutures were placed, to secure the graft–host junction, at the time of keratoplasty. Topography was performed using Pentacam (Oculus) before suture removal. The sutures to be removed in the steep semi-meridians were identified and removed at the slit-lamp biomicroscope. Topography was repeated 30–40 min post suture removal, the new steep semi-meridians determined, and the next set of sutures to be removed were identified and removed accordingly. Topography was repeated 4–6 weeks later and the magnitude of topographic astigmatism was recorded. A paired-samples t-test was used to evaluate the impact of selective suture removal on reducing the magnitude of topographic and refractive astigmatism. Results Twenty eyes of 20 patients underwent sequential selective same-day suture removal (SSSS) after corneal transplantation. This study showed that the topographic astigmatism decreased by about 46.7% (3.68 D) and the refractive astigmatism decreased by about 37.7% (2.61 D) following SSSS. Vector calculations also show a significant reduction of both topographic and refractive astigmatism (P<0.001). Conclusion SSSS may help patients to achieve satisfactory vision more quickly and reduce the number of follow-up visits required post keratoplasty. PMID:23743526

  7. The efficacy of a single continuous nylon suture for control of post keratoplasty astigmatism.

    PubMed Central

    Van Meter, W

    1996-01-01

    PURPOSE: Post operative adjustment of a single continuous suture is an effective means of reducing post keratoplasty astigmatism. This study evaluates post keratoplasty keratometry following suture adjustment with an adjusted suture in place and after the suture is removed. METHODS: Average keratometric astigmatism was measured over 24 months time in 26 patients with an adjusted continuous suture and 24 patients with a continuous suture that was not adjusted. Average keratometry in 43 patients with an adjusted continuous suture was compared with 37 patients with combined continuous and interrupted sutures. Finally, suture out astigmatism in 19 adjusted patients was compared to six patients with no adjustment. RESULTS: There was an increase in average corneal astigmatism over two years of 2.2 diopters in the adjusted group and 1.7 diopters in the non-adjusted group with sutures in place. One year following surgery, average keratometry flattened from 47.5 to 42.9 diopters in the adjusted continuous group and from 47.0 to 46.0 diopters in the group with combined continuous and interrupted sutures. Following suture removal, average astigmatism in patients who had suture adjustment was 4.4 diopters +/- 2.5 diopters (range 1-10 diopters), and 6.01 diopters (range 4-7) in the non-adjusted group. CONCLUSIONS: Average post keratoplasty astigmatism increases after a continuous suture is adjusted but the increase is comparable to patients with acceptable astigmatism who do not require adjustment. More progressive corneal flattening over 12 months time is seen with a continuous suture than which combined sutures. Average suture out astigmatism was 4.0 diopters following suture adjustment, compared to an average of 8.4 diopters prior to adjustment. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 7A FIGURE 7B PMID:8981721

  8. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  9. Retained nuclear fragment found during Descemet-stripping automated endothelial keratoplasty.

    PubMed

    Mifflin, Mark D; Neuffer, Marcus C; Mamalis, Nick

    2011-03-01

    An 82-year-old man with a 2- to 3-month history of progressive visual loss due to corneal edema was referred to our center. The ocular history was significant for uneventful cataract surgery approximately 3 years earlier. Pseudophakic bullous keratopathy was diagnosed and Descemet-stripping automated endothelial keratoplasty (DSAEK) performed. During surgery, a retained nuclear fragment was discovered in the anterior chamber. The fragment was removed and the DSAEK completed successfully. At the 4-month follow-up, the symptoms had completely resolved and the uncorrected distance visual acuity in the affected eye was 20/40. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  10. [Corneal infiltrates after keratoplasty caused by tissue inclusions of corn starch glove powder. An intraoperative complication].

    PubMed

    Mittelviefhaus, H

    1993-12-01

    Corneal infiltrations after keratoplasty may be the first sign of postoperative infection. We report on our findings of unusual corneal infiltrations, which were caused by contamination of the corneal tissue with remnants of latex glove powder. The diagnosis was proved by the specific distribution pattern and the clinical course. Infiltrates of decreasing size were observed in the area of all four temporarily supporting single-stitch sutures of the transplant and at the first stitches of the permanent running corneal sutures. There is no treatment necessary, but the infiltrates have to be differentiated from infection. Improvement of operative habits and techniques can avoid this complication.

  11. [Urgent therapeutic penetrating autokeratoplasty for a purulent corneal ulcer in the only functional eye].

    PubMed

    Onishchenko, A L; Kolbasko, A V; Tatarnikova, G N; Mamontova, É G

    2014-01-01

    The article presents a case of severe purulent corneal ulcer in the only functional eye of a young patient with Frank-Kamenetsky glaucoma and high-degree myopia. Combination therapy was ineffective and the patient developed a descemetocele. Due to the absence of cadaver corneas and small size of the only available conserved Alloplant cornea, the contralateral cornea (of the blind eye, which was enucleated under general anesthesia) was used for urgent therapeutic penetrating autokeratoplasty. Postoperative period was complicated with ocular hypertension, which was surgically resolved. To overcome the critical situation around keratoplasty, with results from Russian regulation gaps, the authors suggest creating interregional eye banks in large cities that would provide sampling, conservation and storage control of donor material in accordance with the existing legislation.

  12. Moon Convention

    NASA Image and Video Library

    2015-03-23

    People with similar jobs or interests hold conventions and meetings, so why shouldn't moons? Pandora, Prometheus, and Pan -- seen here, from right to left -- also appear to be holding some sort of convention in this image. Some moons control the structure of nearby rings via gravitational "tugs." The cumulative effect of the moon's tugs on the ring particles can keep the rings' edges from spreading out as they are naturally inclined to do, much like shepherds control their flock. Pan is a prototypical shepherding moon, shaping and controlling the locations of the inner and outer edges of the Encke gap through a mechanism suggested in 1978 to explain the narrow Uranian rings. However, though Prometheus and Pandora have historically been called "the F ring shepherd moons" due to their close proximity to the ring, it has long been known that the standard shepherding mechanism that works so well for Pan does not apply to these two moons. The mechanism for keeping the F ring narrow, and the roles played -- if at all -- by Prometheus and Pandora in the F ring's configuration are not well understood. This is an ongoing topic for study by Cassini scientists. This view looks toward the sunlit side of the rings from about 29 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 2, 2015. The view was obtained at a distance of approximately 1.6 million miles (2.6 million kilometers) from the rings and at a Sun-ring-spacecraft, or phase, angle of 86 degrees. Image scale is 10 miles (15 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/pia18306

  13. Simple test to confirm cleavage with air between Descemet's membrane and stroma during big-bubble deep anterior lamellar keratoplasty.

    PubMed

    Fontana, Luigi; Parente, Gabriella; Tassinari, Giorgio

    2007-04-01

    We describe a simple test to confirm big-bubble formation in deep anterior lamellar keratoplasty by observing the position and movements of small air bubbles injected into the anterior chamber through a limbal paracentesis. The test also allows evaluation of the extension of Descemet's membrane cleavage from the posterior stroma relative to the margins of the corneal trephination.

  14. Observation on ultrastructure and histopathology of cornea following femtosecond laser-assisted deep lamellar keratoplasty for acute corneal alkaline burns.

    PubMed

    Li, Wen-Jing; Hu, Yu-Kun; Song, Hui; Gao, Xiao-Wei; Zhao, Xu-Dong; Dong, Jing; Guo, Yun-Lin; Cai, Yan

    2016-01-01

    To demonstrate the changes in ultrastructure and histopathology of the cornea in acute corneal alkaline burns after femtosecond laser-assisted deep lamellar keratoplasty. The New Zealand white rabbits treated with alkaline corneal burn were randomized into two groups, Group A (16 eyes) with femtosecond laser-assisted deep lamellar keratoplasty 24h after burn and Group B (16 eyes) without keratoplasty as controls. All eyes were evaluated with transmission electron microscopy (TEM) at 1, 2, 3, and 4wk follow-up, then all corneas were tested by hematoxylin and eosin staining histology. The corneal grafts in Group A were transparent, while those in Group B showed corneal stromal edema and loosely arranged collagen fibers. One week after treatment, TEM revealed the intercellular desmosomes in the epithelial layers and intact non-dissolving nuclei in Group A. At week 4, the center of the corneas in Group A was transparent with regularly arranged collagen fibers and fibroblasts in the stroma. In Group B, squamous cells were observed on the corneal surface and some epithelial cells were detached. Femtosecond laser-assisted deep lamellar keratoplasty can suppress inflammatory responses, prevent toxic substance-induced injury to the corneal endothelium and inner tissues with quicker recovery and better visual outcomes.

  15. Use of an air-fluid exchange system to promote graft adhesion during Descemet's stripping automated endothelial keratoplasty.

    PubMed

    Meisler, David M; Dupps, William J; Covert, Douglas J; Koenig, Steven B

    2007-05-01

    Dislocation of the graft is a well-recognized complication of Descemet's stripping automated endothelial keratoplasty (DSAEK). We describe a technique to promote adhesion of the graft during DSAEK using an anterior chamber air-fluid infusion and exchange for direct control of the pressure and medium used to tamponade the graft against the host stroma.

  16. [Achievements of S. N. Fyodorov's school in the field of keratoplasty and cornea replacement].

    PubMed

    Moroz, Z I; Kalinnikov, Iu Iu; Kovshun, E V; Borzenok, S A; Komakh, Iu A

    2007-01-01

    Reduction in corneal transparence leading to the loss of sight may be caused by different factors, such as eye burns and injuries, keratitis, corneal ulcers, primary and secondary dystrophy, keratoconus, and keratoglobus. In many cases, keratoplasty presents an effective treatment. S. N. Fyodorov made a great contribution to the development of cornea replacement. This was him who placed the entire ophthalmology, including keratoplasty, at the microsurgical level, suggested the use of large-diameter grafts, and was the initiator of establishing the first Eye Tissue Bank. Perfection of microsurgical technique, selection and protection of the graft, as well as new approaches to pre- and postoperation therapy have provided transparent engrafting in 35 to 95%. Presently, Eye Microsurgery Complex is the only Russian institution where the problem of cornea replacement is being worked out as a scientific and practical issue. Three models of keratoprosthesis have been developed: Fyodorov-Zuyev model for implantation into a burn leukoma, Moroz-Glazko model for implantation into a dystrophic leukoma, and a "grid" for implantation into a leukoma of any etiology.

  17. Tectonic Descemet Stripping Automated Endothelial Keratoplasty for the Management of Sterile Corneal Perforations in Decompensated Corneas.

    PubMed

    Nahum, Yoav; Bahar, Irit; Busin, Massimo

    2016-12-01

    To report the use of Descemet stripping automated endothelial keratoplasty (DSAEK) for treatment of sterile corneal perforations accompanying endothelial decompensation. In this multicenter interventional case series, we reviewed the medical records of all tectonic DSAEK surgeries performed at Villa Serena-Villa Igea private Hospitals (Forlì, Italy) and Rabin Medical Center (Petach Tikva, Israel) between January 2014 and March 2016. Three patients with endothelial decompensation and sterile corneal perforation (n = 2) or impending corneal perforation (n = 1) underwent DSAEK between 2014 and 2015 at Villa Igea Hospital, Forlì, Italy, and Rabin Medical Center, Petach Tikva, Israel. All 3 surgeries were performed in eyes with a history of progressive stromal thinning without signs of infection, using the standard DSAEK technique. In 1 eye, surgery was complicated by bleeding into the graft-recipient interface that resolved after intraoperative interface washout. The other 2 procedures were uneventful. In all cases, the graft formed an airtight and watertight barrier, restoring the globe's mechanical integrity. All grafts remained clear throughout follow-up. One eye underwent deep anterior lamellar keratoplasty (DALK on DSAEK) with resulting improvement of visual acuity. Standard DSAEK can be performed in the presence of corneal perforation. Surgery can be a simple technique for closure of sterile corneal perforations while treating endothelial decompensation. Internal tamponade by a lamellar graft can possibly be used in cases of corneal perforations in eyes with a healthy endothelium.

  18. Preliminary results of femtosecond laser-assisted descemet stripping endothelial keratoplasty.

    PubMed

    Cheng, Yanny Y Y; Hendrikse, Fred; Pels, Elisabeth; Wijdh, Robert-Jan; van Cleynenbreugel, Hugo; Eggink, Cathariena A; van Rij, Gabriel; Rijneveld, Wilhelmina J; Nuijts, Rudy M M A

    2008-10-01

    To evaluate the preliminary visual results of femtosecond laser-assisted Descemet stripping endothelial keratoplasty (FS-DSEK). We prospectively analyzed results of 20 consecutive patients with Fuchs endothelial dystrophy or aphakic/pseudophakic bullous keratopathy who underwent FS-DSEK. Best spectacle-corrected visual acuity (BSCVA), refraction, corneal topography, and endothelial cell density were measured preoperatively and 3 and 6 months after FS-DSEK. Corneal thickness was measured using an optical coherence tomography technique. The average BSCVA of 11 eyes with normal visual potential significantly improved from 20/110 +/- 4 lines to 20/57 +/- 1 line at 6 months (P < .007). At 6 months, the mean (SD) hyperopic shift was 2.24 (2.3) diopters (D). Preoperative and 6 months postoperative refractive astigmatism were -0.75 (0.9) D and -1.58 (1.1) D (P = .01), but the topographic astigmatism did not change postoperatively (P = .95). Mean (SD) endothelial cell density at 6 months was 1368 (425) cells/mm(2). There was a persistent deswelling of the graft up to 3 months postoperatively. Complications included graft dislocations requiring repositioning (20%), pupillary block glaucoma (5%), epithelial ingrowth (5%), and primary graft failure (5%). Femtosecond laser-assisted Descemet stripping endothelial keratoplasty was effective in treating endothelial failure with minimal induced refractive astigmatism, limited improvement of BSCVA, and induction of a hyperopic shift. Endothelial cell count and dislocation rate were significant, which may be related to the surgical technique.

  19. Opacification of hydrophilic intraocular lenses after Descemet stripping automated endothelial keratoplasty

    PubMed Central

    Morgan-Warren, Peter J; Andreatta, Walter; Patel, Amit K

    2015-01-01

    Purpose Opacification of hydrophilic acrylic intraocular lenses (IOLs) is an emerging complication following Descemet stripping automated endothelial keratoplasty (DSAEK). We report six cases and review the current literature. Methods In this retrospective, noncomparative, observational case series, patients with IOL opacification after previous DSAEK surgery were identified from corneal clinic records. Case notes were reviewed for demographic details, indication for DSAEK, IOL model, incidence of rebubbling, and postoperative course. Results Six patients developed IOL opacification after DSAEK. All patients had Fuchs’ endothelial dystrophy and had previously received hydrophilic acrylic IOL models. Central anterior IOL opacification was noted in all six cases. Five cases (83%) had required rebubbling due to dislocated graft tissue, and one had an early postoperative intraocular pressure (IOP) rise. Five cases (83%) were managed conservatively, and one case with a failed graft underwent redo DSAEK and IOL exchange. Conclusion Repeated exposure to intracameral air, raised IOP, and other patient influences may be major etiological factors for IOL opacification after DSAEK. We advise avoiding hydrophilic acrylic IOL models in patients who may require future endothelial keratoplasty. PMID:25709389

  20. Surgical outcome of Descemet's stripping automated endothelial keratoplasty for bullous keratopathy secondary to argon laser iridotomy.

    PubMed

    Hirayama, Masatoshi; Yamaguchi, Takefumi; Satake, Yoshiyuki; Shimazaki, Jun

    2012-01-28

    BACKGROUND: To report the 6-month clinical outcome of Descemet's stripping automated endothelial keratoplasty (DSAEK) for bullous keratopathy (BK) secondary to argon laser iridotomy (ALI), and compare the results with those of DSAEK for pseudophakic bullous keratopathy (PBK) or Fuchs' endothelial dystrophy (FED). METHODS: A total of 103 patients (54 with ALI, 28 with PBK, 21 with FED) undergoing DSAEK were retrospectively analyzed. Simultaneous cataract surgery was performed in 37 patients with ALI and 13 with FED. Preoperative ocular conditions, best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction (SE), induced astigmatism, keratometric value, endothelial cell density (ECD), and complications were determined over 6 months postoperatively. RESULTS: Mean axial length in the ALI group (21.8 ± 0.8 mm) was significantly shorter than that in the FED (P = 0.02) or PBK groups (P = 0.003). Severe corneal stromal edema (n = 6), advanced cataract (n = 10), posterior synechia (n = 3), poor mydriasis (n = 5), and Zinn zonule weakness (n = 1) were found only in the ALI group. A significant improvement was observed in postoperative BSCVA in all groups. No significant difference was observed in BSCVA, SE, induced astigmatism, keratometric value, ECD, or complications among the three groups. CONCLUSIONS: Descemet's stripping automated endothelial keratoplasty for BK secondary to ALI showed rapid postoperative visual improvement, with similar efficacy and safety to that observed in DSAEK for PBK or FED.

  1. Big bubble deep anterior lamellar keratoplasty for management of deep fungal keratitis.

    PubMed

    Gao, Hua; Song, Peng; Echegaray, Jose J; Jia, Yanni; Li, Suxia; Du, Man; Perez, Victor L; Shi, Weiyun

    2014-01-01

    Objective. To evaluate the therapeutic effect of big bubble deep anterior lamellar keratoplasty (DALK) in patients with deep fungal keratitis. Methods.Consecutive patients who had DALK for deep fungal keratitis at Shandong Eye Hospital between July 2011 and December 2012 were included. In all patients, the infiltration depth was more than 4/5ths of the corneal thickness. DALK surgery was performed with bare Descemet membrane (DM) using the big bubble technique. Corrected distance visual acuity (CDVA), graft status, and intraoperative and postoperative complications were monitored. Results. Big bubble DALK was performed in 23 patients (23 eyes). Intraoperative perforation of the DM occurred in two eyes (8.7%) during stromal dissection. The patients received lamellar keratoplasty with an air bubble injected into the anterior chamber. Double anterior chamber formed in 3 eyes (13.0%). Mean CDVA of the patients without cataract, amblyopia, and fungal recurrence was improved from preoperative HM/20 cm-1.0 (LogMAR) to 0.23 ± 0.13 (LogMAR) at the last followup (P < 0.01). Fungal recurrence was found in two patients (8.7%). Corneal stromal graft rejection was noted in one patient (4.3%). Conclusions. DALK using the big bubble technique seems to be effective and safe in the treatment of deep fungal keratitis unresponsive to medication.

  2. 'Expanding bubble' modification of 'big-bubble' technique for performing maximum-depth anterior lamellar keratoplasty.

    PubMed

    Daneshgar, F; Fallahtafti, M

    2011-06-01

    To describe a new technique for performing maximum-depth anterior lamellar keratoplasty. This was a case series study using a novel method. We introduce and describe a new sign (sunny-side up sign) that reveals the presence and extent of the air bubble at the Descemet membrane (DM)-stroma interface. We also report a novel technique to expand the bubble by injecting viscoelastic material into the bubble cavity and to excise the stromal tissues within the trephination area almost completely. The follow-up period ranged from 12 to 16 months. In all patients we recorded the best spectacle-corrected visual acuity, keratometry, and endothelial cell count preoperatively and postoperatively and the air bubble diameter using the sunny-side up sign. In eight of nine patients, a big bubble formed. The size of the air bubble ranged from 2 to 7 mm. All the bubbles were expanded to 8 mm and the bare DM throughout the trephination area was obtained in all cases. The postoperative mean keratometric readings were reduced compared with the preoperative mean keratometric readings. The BSCVA was increased postoperatively compared with the preoperative acuity. The difference between the preoperative and postoperative endothelial cell counts was not statistically significant. The early outcomes in our series using the expanding bubble technique suggest that it is safe and easy in performing maximum-depth anterior lamellar keratoplasty.

  3. Microencapsulated Fluorescent Dye Penetrant.

    DTIC Science & Technology

    1979-07-01

    Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

  4. Penetration resistant barrier

    DOEpatents

    Hoover, William R.; Mead, Keith E.; Street, Henry K.

    1977-01-01

    The disclosure relates to a barrier for resisting penetration by such as hand tools and oxy-acetylene cutting torches. The barrier comprises a layer of firebrick, which is preferably epoxy impregnated sandwiched between inner and outer layers of steel. Between the firebrick and steel are layers of resilient rubber-like filler.

  5. Soil penetrometers and penetrability

    USDA-ARS?s Scientific Manuscript database

    Soil penetrometers are useful tools that measure the penetrability, or strength, of a soil. They can be as simple as a rod or shaft with a blunt or sharp end, or complicated mechanically driven instruments with digital data collection systems. Regardless of their design, soil penetrometers measure s...

  6. Single wall penetration equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    1991-01-01

    Five single plate penetration equations are compared for accuracy and effectiveness. These five equations are two well-known equations (Fish-Summers and Schmidt-Holsapple), two equations developed by the Apollo project (Rockwell and Johnson Space Center (JSC), and one recently revised from JSC (Cour-Palais). They were derived from test results, with velocities ranging up to 8 km/s. Microsoft Excel software was used to construct a spreadsheet to calculate the diameters and masses of projectiles for various velocities, varying the material properties of both projectile and target for the five single plate penetration equations. The results were plotted on diameter versus velocity graphs for ballistic and spallation limits using Cricket Graph software, for velocities ranging from 2 to 15 km/s defined for the orbital debris. First, these equations were compared to each other, then each equation was compared with various aluminum projectile densities. Finally, these equations were compared with test results performed at JSC for the Marshall Space Flight Center. These equations predict a wide variety of projectile diameters at a given velocity. Thus, it is very difficult to choose the 'right' prediction equation. The thickness of a single plate could have a large variation by choosing a different penetration equation. Even though all five equations are empirically developed with various materials, especially for aluminum alloys, one cannot be confident in the shield design with the predictions obtained by the penetration equations without verifying by tests.

  7. A novel method to study fluorescein staining of the ocular surface using the fluorescein angiogram setting of the fundus camera.

    PubMed

    Novitskaya, E S; Dean, S; Moore, J; Sharma, A

    2007-09-01

    We present a case of a failed penetrating keratoplasty (PKP), comparing the fluorescein staining of the cornea with the conventional technique, and the new technique using the fluorescein filters of a standard fundus camera.

  8. Penetrating craniofacial arrow injury.

    PubMed

    Jain, Dk; Aggarwal, Gaurav; Lubana, Ps; Moses, Sonia

    2010-01-01

    Arrow injuries are an extinct form of injury in most parts of the developed world, but are still seen, albeit infrequently in developing countries. Reports of penetrating injuries of the craniofacial region secondary to projectiles are few and far between. The morbidity-free outcome of surgical removal, in case of penetrating arrow injuries, despite the delay in presentation and, moreover, in the emergency surgical practice, are the salient points to be remembered whilst managing such cases, for 'what the mind knows is what the eyes see and what the eyes see is what can be practiced'. We report the case of a patient who was attacked by a projectile fired from a crossbow. Immediate surgery under general anesthesia was required to remove the arrow, with utmost care to avoid any neurovascular compromise to the facial nerve, as well as minimize postoperative complications such as otitis media and subsequent meningitis.

  9. Cognitive Penetration and Attention

    PubMed Central

    Gross, Steven

    2017-01-01

    Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. PMID:28275358

  10. Simplified analytical model of penetration with lateral loading -- User`s guide

    SciTech Connect

    Young, C.W.

    1998-05-01

    The SAMPLL (Simplified Analytical Model of Penetration with Lateral Loading) computer code was originally developed in 1984 to realistically yet economically predict penetrator/target interactions. Since the code`s inception, its use has spread throughout the conventional and nuclear penetrating weapons community. During the penetrator/target interaction, the resistance of the material being penetrated imparts both lateral and axial loads on the penetrator. These loads cause changes to the penetrator`s motion (kinematics). SAMPLL uses empirically based algorithms, formulated from an extensive experimental data base, to replicate the loads the penetrator experiences during penetration. The lateral loads resulting from angle of attack and trajectory angle of the penetrator are explicitly treated in SAMPLL. The loads are summed and the kinematics calculated at each time step. SAMPLL has been continually improved, and the current version, Version 6.0, can handle cratering and spall effects, multiple target layers, penetrator damage/failure, and complex penetrator shapes. Version 6 uses the latest empirical penetration equations, and also automatically adjusts the penetrability index for certain target layers to account for layer thickness and confinement. This report describes the SAMPLL code, including assumptions and limitations, and includes a user`s guide.

  11. Penetration Mechanics of Composites

    DTIC Science & Technology

    1992-04-01

    distribution for tensile strength of hollow virgin filaments, based on 128 tests (source: Owens / Corning Fiberglas Corp). 14 1.2 Schematic of split Hopkinson...These were supplied by Owens / Corning Fiberglas Corporation, Granville, Ohio in two forms: 463AA750 (750 yd/lb) roving tow and G150 (1500 yd/lb...penetration of 12.7-mm thick (25-ply) GRP. Targets were fabricated by Owens Corning Fiberglas (OCF) by a licensed process designated HJ1. This complies

  12. Antibody tumor penetration

    PubMed Central

    Thurber, Greg M.; Schmidt, Michael M.; Wittrup, K. Dane

    2009-01-01

    Antibodies have proven to be effective agents in cancer imaging and therapy. One of the major challenges still facing the field is the heterogeneous distribution of these agents in tumors when administered systemically. Large regions of untargeted cells can therefore escape therapy and potentially select for more resistant cells. We present here a summary of theoretical and experimental approaches to analyze and improve antibody penetration in tumor tissue. PMID:18541331

  13. Prediction of alumina penetration

    SciTech Connect

    Mandell, D A

    1993-02-01

    The MESA hydrocode was used to predict two-dimensional tests of L/D 10 and L/D 15 tungsten rods impacting AD 90 alumina with a steel backing. The residual penetration into the steel is the measured quantity in these experiments conducted at the Southwest Research Institute (SWR). The interface velocity as a function of time between an alumina target and a lithium fluoride window, impacted by an alumina disk at velocities between 544 m/s and 2329 m/s, was also predicted. These one-dimensional flyer plate experiments were conducted at Sandia National Laboratories using Coors AD 995 alumina. The material strength and fracture models are important in the prediction of ceramic experiments. The models used in these predictions are discussed. The penetrations in the two-dimensional tests were predicted to 11.4 percent or better. In five of the six experiments, the predicted penetration depth was deeper than the measured value. This trend is expected since the calculation is based on ideal conditions. The results show that good agreement between the 1-D flyer plate data and the MESA predictions exists at the lower impact velocities, but the maximum velocity is overpredicted as the flyer plate velocity increases. At a flyer plate velocity of 2329 m/s the code overpredicted the data by 12.3 percent.

  14. [Penetrating abdominal injuries].

    PubMed

    Nesbakken, A; Pillgram-Larsen, J; Naess, F; Gerner, T; Solheim, K; Stadaas, J O; Gjøra, O

    1990-02-28

    We have reviewed the medical records of 111 patients treated for abdominal stab wounds during the period 1980-87. Our two hospitals serve a catchment area of about 450,000 people. Exploratory laparotomy was performed in 89 patients with suspected peritoneal penetration. In 16 patients the laparotomy was negative, and in 15 patients only minor injuries were noted. There were no serious complications in these 31 patients. Twenty-seven patients had thoracic wounds below the fourth intercostal space, 15 with intraabdominal injuries. The most common injuries were lacerations of the liver, the small bowel and the diaphragm. The mortality in the series was 2%. Stab wounds are infrequent in Norway, and most surgeons have limited experience of such injuries. We discuss whether to employ immediate exploratory laparotomy or selective management when the peritoneum has been penetrated. When there is no evidence of evisceration or omental protrusion, local exploration of the wound should be performed in order to confirm or exclude peritoneal penetration. Injury to the diaphragm and intraabdominal viscera should always be suspected in thoracic stab wounds below the fourth intercostal space.

  15. Mars penetrator: Subsurface science mission

    NASA Technical Reports Server (NTRS)

    Lumpkin, C. K.

    1974-01-01

    A penetrator system to emplace subsurface science on the planet Mars is described. The need for subsurface science is discussed, and the technologies for achieving successful atmospheric entry, Mars penetration, and data retrieval are presented.

  16. Effects of the preparation technique and type of material on the penetrability of sealants.

    PubMed

    Cho, John S; Covey, David; Abdelmegid, Faika; Salama, Fouad

    2015-01-01

    The purpose of this in vitro study was to compare the penetration of 2 resin-based and 2 glass ionomer sealants into fissures after either conventional or mechanical preparation. All the materials placed in the conventionally prepared and mechanically prepared fissures penetrated the fissures beyond the standard (0.5-mm) reference line used in this study. For 1 glass ionomer sealant, the number of specimens showing complete penetration of sealant was significantly greater (P < 0.05) in mechanically prepared fissures than in conventionally prepared ones. No significant differences were found between mechanically and conventionally prepared fissures for the other sealants.

  17. Descemet-stripping automated endothelial keratoplasty: effect of anterior lamellar corneal tissue-on/-off storage condition on Descemet-stripping automated endothelial keratoplasty donor tissue.

    PubMed

    Ide, Takeshi; Yoo, Sonia H; Kymionis, George D; Goldman, James M; Perez, Victor L; O'Brien, Terrence P

    2008-08-01

    To compare the effect of storing Descemet-stripping automated endothelial keratoplasty (DSAEK) tissue with anterior lamellar corneal tissue (ALCT)-on versus -off. An in vitro model was used with corneoscleral rims and DSAEK quality paired corneas. After microkeratome-assisted excision of ALCT, 4 pairs of corneas (8 eyes) were stored with the ALCT left on the stroma (on) and the others with ALCT off the stroma (off) for 24 hours in Optisol GS solution. A vital dye assay was used to identify devitalized and necrotic endothelial cells with alizarin red S and trypan blue. Corneal endothelial cell damage was observed in the ALCT-off specimens, whereas almost no staining was observed in the ALCT-on samples. In addition, the ALCT-off donor corneas were clinically edematous and opaque, whereas the ALCT-on corneas were clear. Moreover, Descemet membranes of ALCT-off samples were found to be loose and easily detached from the stroma, with many Descemet striae observed in the specimens. This study shows that endothelial damage occurs in ALCT-off corneas. We hypothesize that the absence of the Bowman layer may contribute to the damage, because it has been shown that the Bowman layer provides a barrier function. These data suggest that it is important to keep the ALCT/Bowman layer on the stromal side of the DSAEK graft as long as possible to avoid stromal swelling and endothelial damage.

  18. [Confocal microscopy as an early relapse marker after keratoplasty due to Fusarium solani keratitis].

    PubMed

    Daas, L; Bischoff-Jung, M; Viestenz, A; Seitz, B; Viestenz, A

    2017-01-01

    In the case of therapy-resistant keratitis an infection with Fusarium solani should be taken into consideration as a rare but very severe eye disease. In the majority of cases Fusarium solani keratitis will result in a protracted clinical course despite aggressive medicinal and surgical interventions. We describe the case of a referred patient after intensive topical, intracameral and systemic antibacterial and antimycotic therapy as well as surgical treatment with emergency keratoplasty à chaud because of Fusarium solani keratitis. The patient presented to our department with persistent discomfort for further therapeutic interventions. Using confocal microscopy we were able to demonstrate the presence of fungal hyphae in the host cornea and the graft, which was important for making further surgical decisions. Furthermore, this emphasizes the role of confocal microscopy as an early relapse marker during the clinical monitoring.

  19. Descemet-stripping automated endothelial keratoplasty after bee sting of the cornea.

    PubMed

    Hammel, Na'ama; Bahar, Irit

    2011-09-01

    We present a case of corneal decompensation and cataract formation following a corneal bee sting in a patient with a history of drug abuse. Clinical findings, anterior segment photographs, and medical and surgical treatment are presented. The stinger was removed from the cornea. Systemic and topical steroids, topical antibiotics, and systemic and topical antiglaucoma medication and antihistamines were prescribed. After 3 months, combined Descemet-stripping automated endothelial keratoplasty (DSAEK), phacoemulsification, and intraocular lens implantation were performed, with significant improvement in visual acuity and corneal edema. To our knowledge, this is the first report of DSAEK combined with cataract surgery for this condition. It was found to be a safe and effective treatment for corneal decompensation secondary to a bee sting. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  20. Double-bubble technique to facilitate Descemet membrane exposure in deep anterior lamellar keratoplasty.

    PubMed

    Shimazaki, Jun

    2010-02-01

    Safe and efficient exposure of Descemet membrane is the key to success in deep anterior lamellar keratoplasty. Although widely used, the big-bubble technique has the drawback of difficulty in maintaining appropriate needle insertion depth in the corneal stroma, resulting in injected air sometimes escaping to the peripheral cornea without separation of Descemet membrane. We describe a variation of the big-bubble technique in which air is injected into the anterior chamber before it is injected into the stroma. By observing the reflection created on the surface of the air, a needle can be inserted deep into the stroma without puncturing Descemet membrane. This allows safe and efficient separation of Descemet membrane. Moreover, air in the anterior chamber can be used as an indicator of successful Descemet membrane separation as air is shifted to the periphery with creation of the big bubble.

  1. Descemet membrane endothelial keratoplasty: intraoperative and postoperative imaging spectral-domain optical coherence tomography.

    PubMed

    Ang, Marcus; Dubis, Adam M; Wilkins, Mark R

    2015-01-01

    We describe a case report of using the same handheld spectral-domain anterior segment optical coherence tomography (ASOCT) for rapid intraoperative and postoperative imaging in a case of Descemet membrane endothelial keratoplasty (DMEK). A 67-year-old woman, with Fuchs dystrophy and corneal decompensation, underwent DMEK with intraoperative ASOCT imaging using the handheld Envisu spectral domain ASOCT system (Bioptigen, Inc., Morrisville, NC, USA). We found that this easy-to-use portable system with handheld probe allowed for rapid imaging of the anterior segment during donor manipulation to visualize the orientation of the DMEK donor, as well as to confirm the initial adhesion of the DMEK donor. Moreover, the same system may be used for postoperative monitoring of graft adhesion, corneal thickness, and stromal remodeling in the clinic with very high-definition images.

  2. Comparison of synthetic glues and 10-0 nylon in rabbit lamellar keratoplasty.

    PubMed

    Cho, Soon Young; Kim, Man Soo; Oh, Su Ja; Chung, Sung Kun

    2013-09-01

    To evaluate changes in mean keratometry and to compare wound repair with corneal lamellar grafts in rabbit eyes using human synthetic tissue adhesives and 10-0 nylon. Corneal grafts were made using a 6.0-mm-diameter trephine and blades in the eyes of 15 New Zealand white rabbits. Human fibrin tissue adhesive (Tisseel) was used in group 1, human fibrin tissue adhesive (Beriplast P) was used in group 2, polyethylene glycol adhesive (Coseal) was used in group 3, and 8 bite sutures with 10-0 nylon were used in group 4 (control) for lamellar keratoplasty. Four bite sutures were made with 10-0 nylon in groups 1, 2, and 3. Slit-lamp microscopy and keratometry were performed at 3 days and 1, 2, and 4 weeks after the surgery. Histopathologic and electromicroscopic examinations were performed 4 weeks after the surgery. No inflammation or corneal toxicity was seen in groups 1 and 2. Histologically, a few inflammatory cells were seen in groups 3 and 4. Groups 1, 2, and 3 showed no statistically significant changes in mean keratometry at 4 weeks postoperatively compared with preoperative mean keratometry (Wilcoxon signed-rank test, P = 0.178, 0.208, and 0.889, respectively). The control group showed significant changes in mean keratometry at 4 weeks postoperatively (Wilcoxon signed-rank test, P = 0.018). Human fibrin tissue adhesives were well tolerated in rabbit eyes, with no apparent corneal toxicity. Polyethylene glycol adhesive showed more inflammation and insufficient wound repair compared with human fibrin tissue adhesives. Therefore, human fibrin tissue adhesives can be used as an alternative to sutures in lamellar keratoplasty.

  3. Evaluation of internationally shipped prestripped donor tissue for descemet membrane endothelial keratoplasty by vital dye staining.

    PubMed

    Kobayashi, Akira; Murata, Noriaki; Yokogawa, Hideaki; Yamazaki, Natsuko; Masaki, Toshinori; Sugiyama, Kazuhisa

    2015-02-01

    The aim of this study was to evaluate endothelial cell damage of internationally shipped prestripped donor tissue for Descemet membrane endothelial keratoplasty (DMEK) using vital dye staining. Six internationally shipped prestripped DMEK donors were stained with trypan blue and were subsequently photographed before they were cut with a trephine. Quantitative analysis assessment of endothelial damage of the donor graft area (8.0 mm in diameter) was performed using Adobe Photoshop CS6 Extended software. Seven internationally shipped precut Descemet stripping automated endothelial keratoplasty (DSAEK) donors were used as controls. No statistical differences were noted between prestripped DMEK donors and precut DSAEK donors in mean donor age (67.7 vs. 56.4 years, P = 0.222), mean donor endothelial cell density (2687.3 vs. 2894.6 cells, P = 0.353), and death-to-preservation time (405.3 vs. 558.4 minutes, P = 0.173). However, the mean time of death-to-experiment time in DMEK donors was significantly longer than that of DSAEK donors (8.7 vs. 6.6 days, P = 0.031). Mean endothelial cell damage of prestripped DMEK donors was as low as 0.3%. However, DMEK donor endothelial damage (0.3%) was significantly higher compared with that of precut DSAEK donor tissue (0.01%, P = 0.029). Although endothelial damage of internationally shipped prestripped donor tissue for DMEK was higher than that of precut DSAEK donor, it was extremely low. Further evaluation using another vital dye and clinical studies may be needed to confirm this study.

  4. Combined astigmatic keratotomy and conductive keratoplasty to correct high corneal astigmatism.

    PubMed

    Sy, Mary Ellen; Kovoor, Timmy A; Tannan, Anjali; Choi, Daniel; Deng, Sophie X; Danesh, Jennifer; Hamilton, D Rex

    2015-05-01

    To determine the safety, efficacy, and predictability of combined astigmatic keratotomy (AK) and conductive keratoplasty (CK) for treating high corneal astigmatism. University of California-Los Angeles, Los Angeles, California, USA. Retrospective case series. From January 1, 2004, to December 31, 2009, AK and CK were performed in eyes with corneal astigmatism of 5.0 diopters (D) or more after keratoplasty or trauma. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), defocus equivalent, mean astigmatism, efficacy index, and complications were evaluated. In 11 eyes of 11 patients, the mean UDVA improved from 1.54 logMAR ± 0.50 (SD) preoperatively to 0.69 ± 0.62 logMAR 3 months postoperatively (P < .001) and the mean CDVA from 0.55 ± 0.62 logMAR to 0.12 ± 0.11 logMAR (P = .028). The mean SE and mean defocus equivalent decreased from -1.25 ± 5.06 D to 3.13 ± 3.06 D (P = .15) and from 7.98 ± 4.41 D to 6.97 ± 3.73 D (P = .45), respectively; these changes were not statistically significant. The mean absolute astigmatism decreased from 10.25 ± 4.71 D to 4.31 ± 2.34 D (P < .001). The mean absolute orthogonal and mean oblique astigmatism showed a statistically significant decrease. The efficacy index was 0.82. One case of wound gape after AK required suturing. No infectious keratitis, corneal perforation, or graft rejection occurred. Results indicate that combined AK and CK is safe and effective for correcting high corneal astigmatism after surgery or trauma. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  5. Descemet-membrane endothelial keratoplasty in patients with retinal comorbidity-a prospective cohort study

    PubMed Central

    Spaniol, Kristina; Holtmann, Christoph; Schwinde, Jan-Hendrik; Deffaa, Sophia; Guthoff, Rainer; Geerling, Gerd

    2016-01-01

    AIM To investigate indications, surgical challenges, and outcome of Descemet-membrane endothelial keratoplasty (DMEK) in patients with retinal comorbidities (RC). METHODS In a prospective cohort study, 8 eyes of 8 DMEK-patients with known RC were compared to 38 eyes of 38 DMEK-patients without RC. The duration of surgery, the degree of difficulty graded by the surgeon, and the complications through DMEK-surgery were analyzed for each patient. The best-corrected visual acuity (BCVA), the endothelial cell count, the intraocular pressure, and the subjective satisfaction was evaluated after a 6-month follow-up. Data were compared applying the non-parametric Wilcoxon-, Chi-square- and Fisheŕs-exact-test with P≤0. 05 as level of significance. RESULTS RC-patients had dry age-related macular degeneration (n=4) or history of pars-plana vitrectomy (n=4). The main indication for DMEK was pain due to bullous keratopathy for the RC-patients (n=7, 88%) and visual impairment due to Fuchs endothelial keratoplasty for the non-RC-patients (n=33, 87%). The BCVA increased for both groups (P=0.01, P<0.001) and all corneas cleared. For the RC-patients, the subjective satisfaction improved significantly (P=0.02). Oil-filling and missing support of the vitreous body complicated surgery in vitrectomized eyes. CONCLUSION DMEK is a favorable technique to treat endothelial disorders even if patients suffer from a retinal comorbidity. By enhancing the corneal clarity, it enables retinal examination or intraocular surgery and increases the patientś satisfaction. However, in vitrectomized or silicone-oil filled eyes, the duration of surgery and degree of complexity are increased. An experienced surgeon should perform DMEK in these patients. Clinical trial registration number: DRKS00007566. PMID:27158608

  6. Multicenter Study of 6-Month Clinical Outcomes After Descemet Membrane Endothelial Keratoplasty.

    PubMed

    Oellerich, Silke; Baydoun, Lamis; Peraza-Nieves, Jorge; Ilyas, Abbas; Frank, Laurence; Binder, Perry S; Melles, Gerrit R J

    2017-09-26

    To report the 6-month clinical outcomes of a large cohort of Descemet membrane endothelial keratoplasty (DMEK) eyes operated by 55 starting or experienced surgeons. This is a retrospective, multicenter, interventional, cohort study with a total of 2485 eyes. Best-corrected visual acuity (BCVA), endothelial cell density (ECD) decrease, and intra- and post-operative complications were evaluated. Three groups based on case order were compared: group I (cases 1-24), group II (cases 25-99), and group III (cases ≥100). Forty-nine percent of the surgeons were in their learning curve (<25 cases), representing 10.4% of the surgeries. Six months after DMEK, BCVA improved in 90.5% of eyes, remained unchanged in 4.6%, and deteriorated in 4.9% (n = 1936); 75.4% of eyes reached a BCVA of ≥20/40 (≥0.5), 45.4% ≥20/25 (≥0.8), and 25.8% ≥20/20 (≥1.0) (n = 1959) and ECD decreased by 40% (±19) (n = 1272, P < 0.05). BCVA and ECD outcomes did not differ between groups I and III (P > 0.05). Intraoperative complications were reported for 9.4% of eyes, whereas graft detachment was the main postoperative complication (27.4%), with lower intra- and post-operative complication rates in group III than group I (P < 0.05). Rebubbling was performed in 20.1% of eyes; 13.8% required secondary keratoplasty within 6 months. DMEK is applicable for surgeons in various settings with good clinical outcomes. After an arbitrary learning curve (<25 cases), virtually all transplant-related complications declined with experience. Notably, surgeons with a higher annual caseload may pass faster through their learning curve than surgeons performing their first surgeries over an extended period.

  7. Penetrating neck traumas

    PubMed Central

    Kaczmarski, Jacek; Brzeziński, Daniel; Cieślik-Wolski, Bartosz; Kozak, Józef

    2014-01-01

    Aim of the study Aim of the study is to present our own experiences in the treatment of people suffering from penetrating neck traumas. Material and methods In the years 1996-2012, 10 patients with penetrating neck traumas were treated, including 3 women and 7 men. The patients’ age ranged from 16 to 55 (the average age being 40.7 years). In 9 cases the wound was caused by cutting or stabbing, while in one case it was inflicted by a gunshot. In 8 patients it was a single cut wound, while one patient suffered from 34 stab wounds to the neck, chest and stomach. Two cut wounds resulted from a suicide attempt. The remaining injuries were the result of a crime. Results All patients underwent immediate surgery, which involved revision of the neck wounds in 8 cases, one longitudinal sternotomy and one left-sided thoracotomy. The indications for surgery included increased subcutaneous emphysema in 5 patients, bleeding from the wound in 3 patients, and mediastinal hematoma in 2 patients. The damage assessed intraoperatively included tracheal damage in 6 patients, damage to carotid vessels in 3 patients, larynx in 2 patients, thoracic vessels in 2 patients, oesophagus in 1 patient and thyroid gland in 1 patient. In 9 patients, the treatment yielded positive results. The patient with a gunshot wound died during the surgery due to massive bleeding from the aorta. Conclusions In patients with penetrating neck wounds, early and rapid diagnostics allows one to determine the indications for surgery and prevent serious fatal complications. PMID:26336390

  8. The deep penetrating nevus.

    PubMed

    Strazzula, Lauren; Senna, Maryanne Makredes; Yasuda, Mariko; Belazarian, Leah

    2014-12-01

    The deep penetrating nevus (DPN), also known as the plexiform spindle cell nevus, is a pigmented lesion that commonly arises on the head and neck in the first few decades of life. Histopathologically, the DPN is wedge-shaped and contains melanocytes that exhibit deep infiltration into the dermis. Given these features, DPN may clinically and histopathologically mimic malignant melanoma, sparking confusion about the appropriate evaluation and management of these lesions. The goal of this review is to summarize the clinical and histopathological features of DPN and to discuss diagnostic and treatment strategies for dermatologists.

  9. Penetrating thoracic trauma.

    PubMed

    Bastos, Renata; Baisden, Clinton E; Harker, Lori; Calhoon, John H

    2008-01-01

    The initial approach to penetrating thoracic trauma is directed towards the pathophysiologic syndrome upon presentation. Most patients are successfully treated with drainage tubes. The unstable patient may necessitate thoracotomy at the emergency room to drain cardiac tamponade, provide cardiac massage and control bleeding. The guidelines for this procedure are reviewed. Need for further work-up of potential injuries to other mediastinal organs is frequently screened by computerized tomography. Surgery might still be needed, on a less emergent basis, in order to repair injuries to the trachea/esophagus, retained hemothorax, or to rule out diaphragmatic injury. Laparoscopic and thoracoscopic procedures may be used in specific situations.

  10. Penetrating Fire Extinguisher

    NASA Technical Reports Server (NTRS)

    1985-01-01

    When Feecon Corporation, a manufacturer of fire protection systems, needed a piercing nozzle for larger aircraft, they were assisted by Kennedy Space Center who provided the company with a fire extinguisher with a hard pointed tip that had been developed in case of an orbiter crash landing. The nozzle can penetrate metal skins of aircraft, trains, etc. Feecon obtained a license and now markets its cobra ram piercing nozzle to airport firefighters. Its primary advantage is that the nozzle can be held in one spot during repeated blows of the ram. *This product has been discontinued and is no longer commercially available.

  11. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  12. Overview - Hard Rock Penetration

    SciTech Connect

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  13. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  14. Monolithic ballasted penetrator

    DOEpatents

    Hickerson, Jr., James P.; Zanner, Frank J.; Baldwin, Michael D.; Maguire, Michael C.

    2001-01-01

    The present invention is a monolithic ballasted penetrator capable of delivering a working payload to a hardened target, such as reinforced concrete. The invention includes a ballast made from a dense heavy material insert and a monolithic case extending along an axis and consisting of a high-strength steel alloy. The case includes a nose end containing a hollow portion in which the ballast is nearly completely surrounded so that no movement of the ballast relative to the case is possible during impact with a hard target. The case is cast around the ballast, joining the two parts together. The ballast may contain concentric grooves or protrusions that improve joint strength between the case and ballast. The case further includes a second hollow portion; between the ballast and base, which has a payload fastened within this portion. The penetrator can be used to carry instrumentation to measure the geologic character of the earth, or properties of arctic ice, as they pass through it.

  15. Sand Penetration Experiments

    NASA Astrophysics Data System (ADS)

    Bless, Stephan; Berry, Don; Lawhorn, William

    2009-06-01

    In an experimental program, steel bullets and short cylinders, and tungsten alloy rods were shot into dry silica sand at 600 to 1100 m/s. The rods included finsets that were designed for aerodynamic stabilization. The fins also apparently provided trajectory stabilization within the sand as well. Time-of-arrival screens allowed measurement of velocity. Analysis of those data indicated that drag coefficients increased as projectiles slowed down. Comparison with previous data indicates there was a slight increase in drag coefficient of rods over expected values for unfinned rods; however, the net result was penetration normalized by length was as high as 40, depending on nose shape. It was found that when the velocity exceeded about 80 m/s (which is close to the speed of sound in sand) sand particles were broken down into their constituent grains, resulting in a decrease in size by about 1000. Normalized penetration is expected to scale as kinetic energy per unit area, and it was significantly higher for the rods than for the other projectiles. This is attributed to stabilization from interaction of the fins with the cavity wall.

  16. Penetration in GTA welding

    SciTech Connect

    Heiple, C.R.; Burgardt, P.

    1990-01-01

    The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

  17. Intraoperative use of spectral-domain optical coherence tomography during Descemet’s stripping automated endothelial keratoplasty

    PubMed Central

    Sng, Chelvin CA; Gimeno, Federico Luengo; Mehta, Jodhbir S; Htoon, Hla Myint; Tan, Donald T

    2012-01-01

    Purpose To evaluate the intraoperative changes in the donor lenticule, recipient cornea, and the reduction of interface fluid thickness during Descemet’s stripping and automated endothelial keratoplasty with EndoGlide™ (Angiotech Pharmaceuticals Inc, Vancouver, Canada) donor insertion, using intraoperative spectral-domain optical coherence tomography. Methods Prospective observational case series of patients underwent Descemet’s stripping and automated endothelial keratoplasty using the EndoGlide inserter. Spectral-domain optical coherence tomography (iVue; Optovue Inc, Fremont, CA) with a handheld probe was used to image the cornea and anterior chamber. Standardized software was used to measure interface fluid gap, host cornea, and donor lenticule thicknesses during the following surgical stages of Descemet’s stripping and automated endothelial keratoplasty: (1) after donor insertion and immediately before full air tamponade; (2) after air tamponade and expression of fluid from venting incisions; (3) at 6 minutes of air tamponade; and (4) at 10 minutes of air tamponade. Results Ten patients with a mean age of 74.9 ± 11.8 years were recruited. Spectral-domain optical coherence tomography measurements of the interface fluid gap after fluid was expressed through the venting incisions (P < 0.001), at 6 minutes of air tamponade (P < 0.001) and at 10 minutes of air tamponade (P < 0.001 and P = 0.001, respectively), were significantly decreased compared to the measurements immediately before air tamponade. Donor thickness increased significantly at 6 minutes of air tamponade (P = 0.004) but reduced by 10 minutes compared to immediately before air tamponade. Conclusion Significant intraoperative changes in the donor, recipient cornea, and interface fluid thickness occurred following endothelial keratoplasty donor insertion. PMID:22536040

  18. Refractive keratoplasty

    SciTech Connect

    Schwab, I.R. )

    1987-01-01

    This book contains 12 chapters. Some of the titles are: Perspectives on refractive surgery; Radial keratotomy; The refractive aspects of corneal transplantation; Wedge resection and relating incisions; Laser surgery of the cornea; and All plastic corneal lenses.

  19. Femtosecond laser-assisted keratoplasty combined with cataract extraction in a patient with keratoconus and oculocutaneous albinism

    PubMed Central

    Pásztor, Dorottya; Kolozsvári, Bence Lajos; Losonczy, Gergely; Fodor, Mariann

    2016-01-01

    In this study, we present a case of a 58-year-old male patient with oculocutaneous albinism, keratoconus, total cataract, and glaucoma originating from father-daughter incest. He underwent femtosecond laser-assisted keratoplasty with “open-sky” cataract extraction and posterior chamber intraocular lens implantation. One week after surgery his uncorrected visual acuity improved from hand motion to 20/200. Six months later corneal K values were 49.1 D in the flat and 50.0 D in the steep meridian. The graft had a central corneal thickness of 488 µm and was well fitted. The patient's quality of life improved substantially due to the surgery. To the best of our knowledge, this is the first report on the association of albinism with advanced keratoconus, total cataract, and glaucoma. Moreover, no previous report on femtosecond laser-assisted keratoplasty using VisuMax femtosecond laser system with “open-sky” cataract extraction is available in the literature. The VisuMax femtosecond laser-assisted keratoplasty ensures fast patient rehabilitation in such challenging cases. PMID:27146942

  20. Water penetration study

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.

    1973-01-01

    Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. An experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.

  1. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, Phillip W.; Stampfer, Joseph F.; Bradley, Orvil D.

    1999-01-01

    A universal penetration test apparatus for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material.

  2. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, P.W.; Stampfer, J.F.; Bradley, O.D.

    1999-02-02

    A universal penetration test apparatus is described for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material. 23 figs.

  3. Ballistic penetration response of intermetallic matrix composites

    SciTech Connect

    Kumar, K.S.; DiPietro, M.S. )

    1995-03-01

    Titanium aluminides and their composites exhibit about the same density as alumina, are tougher and can be produced by conventional casting and powder metallurgy techniques; further, they can be ground and machined more easily than alumina and lend themselves to better microstructural manipulation via heat treatments. Graded composite tiles with a high refractory reinforcement content on the outside and a lower amount on the inside may provide the desired abrasion resistance and toughness to effectively stop an incoming projectile. Likewise, alternating layers of hard and soft materials (e.g. Ti foils and TiAl) suitably graded in their spacings can serve as an effective armor tile. Testing of these materials gave the following conclusions: (1) Titanium aluminide composites are comparable to alumina in ballistic penetration resistance (for BS-41 and M-61 AP threats, and from the work of Chin and Woolsey, to long-rod penetrators) with perhaps improved resistance to shattering. (2) Incorporation of a residual compressive stress in the titanium aluminide composite tile significantly improved its penetration resistance. This concept could be utilized to decrease the required minimum tile thickness and hence, overall system weight.

  4. Electrospun nanofibrous SF/P(LLA-CL) membrane: a potential substratum for endothelial keratoplasty

    PubMed Central

    Chen, Junzhao; Yan, Chenxi; Zhu, Mengyu; Yao, Qinke; Shao, Chunyi; Lu, Wenjuan; Wang, Jing; Mo, Xiumei; Gu, Ping; Fu, Yao; Fan, Xianqun

    2015-01-01

    Background Cornea transplant technology has progressed markedly in recent decades, allowing surgeons to replace diseased corneal endothelium by a thin lamellar structure. A thin, transparent, biocompatible, tissue-engineered substratum with corneal endothelial cells for endothelial keratoplasty is currently of interest. Electrospinning a nanofibrous structure can simulate the extracellular matrix and have beneficial effects for cell culture. Silk fibroin (SF) has good biocompatibility but poor mechanical properties, while poly(l-lactic acid-co-ε-caprolactone) (P(LLA-CL)) has good mechanical properties but poor biocompatibility. Blending SF with P(LLA-CL) can maintain the advantages of both these materials and overcome their disadvantages. Blended electrospun nanofibrous membranes may be suitable for regeneration of the corneal endothelium. The aim of this study was to produce a tissue-engineered construct suitable for endothelial keratoplasty. Methods Five scaffolds containing different SF:P(LLA-CL) blended ratios (100:0, 75:25, 50:50, 25:75, 0:100) were manufactured. A human corneal endothelial (B4G12) cell line was cultured on the membranes. Light transmission, speed of cell adherence, cell viability (live-dead test), cell proliferation (Ki-67, BrdU staining), and cell monolayer formation were detected on membranes with the different blended ratios, and expression of some functional genes was also detected by real-time polymerase chain reaction. Results Different blended ratios of scaffolds had different light transmittance properties. The 25:75 blended ratio membrane had the best transmittance among these scaffolds. All electrospun nanofibrous membranes showed improved speed of cell adherence when compared with the control group, especially when the P(LLA-CL) ratio increased. The 25:75 blended ratio membranes also had the highest cell proliferation. B4G12 cells could form a monolayer on all scaffolds, and most functional genes were also stably expressed on all

  5. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  6. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  7. Penetration enhancer-containing vesicles: composition dependence of structural features and skin penetration ability.

    PubMed

    Manconi, M; Caddeo, C; Sinico, C; Valenti, D; Mostallino, M C; Lampis, S; Monduzzi, M; Fadda, A M

    2012-10-01

    In this work, we focused on how composition and preparation method of vesicles might affect their morphological features and delivery performances. Penetration Enhancer-containing Vesicles, PEVs, vesicles containing a water miscible penetration enhancer (Transcutol® P; 10%, 20%, 30% v/v) and encapsulating diclofenac sodium, were formulated and compared with conventional liposomes. A cheap and unpurified commercial mixture of phospholipids, fatty acids, and triglycerides (Phospholipon® 50) was used, and the effects of this heterogeneous composition (along with the presence or absence of transcutol and the production method) on vesicle morphology, size, surface charge, drug loading, and stability were investigated. The variations in vesicle structure, bilayer thickness, and number of lamellae were assessed by TEM and Small and Wide Angle X-ray Scattering, which also proved the liquid state of the vesicular bilayer. Further, vesicles were evaluated for ex vivo (trans)dermal delivery, and their mode of action was studied performing a pre-treatment test and confocal laser scanning microscopy analyses. Results showed the formation of multi- and unilamellar vesicles that provided improved diclofenac delivery to pig skin, influenced by vesicle lipid composition and structure. Images of the qualitative CLSM analyses support the conclusion that PEVs enhance drug transport by penetrating intact the stratum corneum, thanks to a synergic effect of vesicles and penetration enhancer. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Top Sounder Ice Penetration

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Goemmer, S. A.; Sweeney, J. H.

    2014-12-01

    Ice draft measurements are made as part of normal operations for all US Navy submarines operating in the Arctic Ocean. The submarine ice draft data are unique in providing high resolution measurements over long transects of the ice covered ocean. The data has been used to document a multidecadal drop in ice thickness, and for validating and improving numerical sea-ice models. A submarine upward-looking sonar draft measurement is made by a sonar transducer mounted in the sail or deck of the submarine. An acoustic beam is transmitted upward through the water column, reflecting off the bottom of the sea ice and returning to the transducer. Ice thickness is estimated as the difference between the ship's depth (measured by pressure) and the acoustic range to the bottom of the ice estimated from the travel time of the sonar pulse. Digital recording systems can provide the return off the water-ice interface as well as returns that have penetrated the ice. Typically, only the first return from the ice hull is analyzed. Information regarding ice flow interstitial layers provides ice age information and may possibly be derived with the entire return signal. The approach being investigated is similar to that used in measuring bottom sediment layers and will involve measuring the echo level from the first interface, solving the reflection loss from that transmission, and employing reflection loss versus impedance mismatch to ascertain ice structure information.

  9. Electromagnetic Field Penetration Studies

    NASA Technical Reports Server (NTRS)

    Deshpande, M.D.

    2000-01-01

    A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

  10. Static penetration resistance of soils

    NASA Technical Reports Server (NTRS)

    Durgunoglu, H. T.; Mitchell, J. K.

    1973-01-01

    Model test results were used to define the failure mechanism associated with the static penetration resistance of cohesionless and low-cohesion soils. Knowledge of this mechanism has permitted the development of a new analytical method for calculating the ultimate penetration resistance which explicitly accounts for penetrometer base apex angle and roughness, soil friction angle, and the ratio of penetration depth to base width. Curves relating the bearing capacity factors to the soil friction angle are presented for failure in general shear. Strength parameters and penetrometer interaction properties of a fine sand were determined and used as the basis for prediction of the penetration resistance encountered by wedge, cone, and flat-ended penetrometers of different surface roughness using the proposed analytical method. Because of the close agreement between predicted values and values measured in laboratory tests, it appears possible to deduce in-situ soil strength parameters and their variation with depth from the results of static penetration tests.

  11. An Earth Penetrating Modeling Assessment

    SciTech Connect

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  12. Hepatic abscess secondary to a fishbone penetrating the gastric wall: CT demonstration.

    PubMed

    Masunaga, S; Abe, M; Imura, T; Asano, M; Minami, S; Fujisawa, I

    1991-01-01

    Preoperative diagnosis of hepatic abscess due to foreign bodies penetrating the gastrointestinal tract is uncommon with conventional imaging methods. This report describes and illustrates a case of hepatic abscess secondary to a fishbone penetrating the gastric antrum wall which was diagnosed preoperatively by CT and confirmed at surgery. The value of CT in the preoperative diagnosis of cases of this kind is emphasized.

  13. ASC-AD penetration modeling FY05 status report.

    SciTech Connect

    Kistler, Bruce L.; Ostien, Jakob T.; Chiesa, Michael L.; Bhutani, Nipun; Ohashi, Yuki; Marin, Esteban B.; Korellis, John S.; Settgast, Randy; Antoun, Bonnie R.

    2006-04-01

    Sandia currently lacks a high fidelity method for predicting loads on and subsequent structural response of earth penetrating weapons. This project seeks to test, debug, improve and validate methodologies for modeling earth penetration. Results of this project will allow us to optimize and certify designs for the B61-11, Robust Nuclear Earth Penetrator (RNEP), PEN-X and future nuclear and conventional penetrator systems. Since this is an ASC Advanced Deployment project the primary goal of the work is to test, debug, verify and validate new Sierra (and Nevada) tools. Also, since this project is part of the V&V program within ASC, uncertainty quantification (UQ), optimization using DAKOTA [1] and sensitivity analysis are an integral part of the work. This project evaluates, verifies and validates new constitutive models, penetration methodologies and Sierra/Nevada codes. In FY05 the project focused mostly on PRESTO [2] using the Spherical Cavity Expansion (SCE) [3,4] and PRESTO Lagrangian analysis with a preformed hole (Pen-X) methodologies. Modeling penetration tests using PRESTO with a pilot hole was also attempted to evaluate constitutive models. Future years work would include the Alegra/SHISM [5] and AlegrdEP (Earth Penetration) methodologies when they are ready for validation testing. Constitutive models such as Soil-and-Foam, the Sandia Geomodel [6], and the K&C Concrete model [7] were also tested and evaluated. This report is submitted to satisfy annual documentation requirements for the ASC Advanced Deployment program. This report summarizes FY05 work performed in the Penetration Mechanical Response (ASC-APPS) and Penetration Mechanics (ASC-V&V) projects. A single report is written to document the two projects because of the significant amount of technical overlap.

  14. Three-Dimensional Construction of a Rabbit Anterior Corneal Replacement for Lamellar Keratoplasty

    PubMed Central

    Pang, Kunpeng; Du, Liqun; Zhang, Kai; Dai, Chenyang; Ju, Chengqun; Zhu, Jing; Wu, Xinyi

    2016-01-01

    The aim of this study was to construct a rabbit anterior corneal replacement for transplantation using acellular porcine corneal matrix (APCM) and rabbit epithelial or stromal cells. APCM was prepared from fresh porcine cornea treated with 0.5% (wt./vol.) sodium dodecyl sulfate (SDS) solution. The expanded stromal cells were first injected into APCM parallel to its surface and were cultured in a shaking culture system for 7 days to obtain the stromal construct. Next, corneal epithelial cells were cultured on the stromal construct surface for another 7 days to obtain rabbit anterior corneal lamella. The construct had a phenotype similar to that of normal cornea, with high expression of cytokeratin 3 in the epithelial cell layer and vimentin in the stromal cells. More importantly, the construct integrated well with the implanted host corneal tissue, and the implant cornea maintained transparency in the 6-month follow-up, although there was a slight haze in the central corneal area. The endothelium in the surgery cornea had a similar cell density and mosaic pattern with normal cornea as shown by confocal laser corneal microscopy, and the regenerated corneal epithelial cells on the implant surface showed a similar morphology to that of natural epithelial cells. These results demonstrate that the constructed anterior corneal replacement exhibits an excellent biological property for lamellar keratoplasty and might be a possible alternative to human corneal tissue in the future. PMID:27930708

  15. Comparison of femtosecond laser-assisted descemetic and predescemetic lamellar keratoplasty for keratoconus

    PubMed Central

    Lu, Yan; Grisolia, Ana Beatriz Diniz; Ge, Yi-Rui; Xue, Chun-Yan; Cao, Qian; Yang, Li-Ping; Huang, Zhen-Ping

    2017-01-01

    Purpose: The purpose of this study is to compare the outcomes following femtosecond laser-assisted deep anterior lamellar keratoplasty (DALK) with 75% of stromal dissection (predescemetic group) and femtosecond laser-assisted DALK using big-bubble technique with total stromal resection (descemetic group) for the treatment of keratoconus. Subjects and Methods: Twenty eyes of 17 patients with keratoconus were studied. There were 10 eyes of 9 patients in predescemetic group and 10 eyes of 8 patients in descemetic group. The postoperative best-corrected visual acuity (BCVA), manifest refraction, keratometry, endothelial cell density (ECD), and central corneal thickness (CCT) were analyzed. Results: All surgeries were performed uneventfully. At 1 year after surgery, the BCVA, corneal astigmatism, keratometry, CCT, and ECD between two groups were not statistically significant (all P > 0.05). However, the mean manifest refraction was −9.43 ± 7.44 diopter (D) and −1.03 ± 1.13D in predescemetic and descemetic groups, respectively, which was statistically significant between two groups (P < 0.05). Conclusions: The results of BCVA and corneal astigmatism, keratometry, ECD, and CCT were comparable between two groups. However, the mean postoperative manifest refraction was lower in descemetic group. PMID:28300735

  16. A novel method in preparation of acellularporcine corneal stroma tissue for lamellar keratoplasty

    PubMed Central

    Shao, Yi; Tang, Jing; Zhou, Yueping; Qu, Yangluowa; He, Hui; Liu, Qiuping; Tan, Gang; Li, Wei; Liu, Zuguo

    2015-01-01

    Our objective was to develop a novel lamellar cornealbiomaterial for corneal reconstruction.Theporcine acellular corneal stroma discs (ACSDs) were prepared from de-epithelized fresh porcine corneas (DFPCs) by incubation with 100% fresh human serum and additional electrophoresis at 4°C. Such manipulation removed theanterior corneal stromal cells without residual of DNA content and α-Galantigen. Human serum decellularizing activity on porcineanterior corneal stroma cells is through apoptosis, and associated with the presence of α-Gal epitopes in anterior stroma. ACSDs displayed similar optical, biomechanical properties and ultrastructure to DFPCs, and showed good histocompatibility in rabbit corneal stromal pockets and anterior chamber. Rabbit corneallamellar keratoplasty (LKP) using ACSDs showed no rejection and high transparency of cornea at 2 months after surgery. In vivo confocal laser scanning microscopy and immunostaining analysis showed complete re-epithelization and stromal cell in growth of ACSDs without inflammatory cell infiltration, new blood vessel ingrowth and excessive wound healing. In conclusion, this novel decellularization method may be valuable for preparation of xenogenic corneal tissue for clinical application, ACSDs resulted from this method may be served as a matrix equivalent for LKP in corneal xenotransplantation. PMID:26885261

  17. Continuous intraoperative OCT guided management of post-deep anterior lamellar keratoplasty descemet's membrane detachment.

    PubMed

    Sharma, Namrata; Aron, Neelima; Kakkar, Prateek; Titiyal, Jeewan S

    2016-01-01

    Continuous intraoperative optical coherence tomography (iOCT) integrated into the operating microscope is a new modification in the current operating microscope to aid in the surgical procedures involving both the anterior and the posterior segment. This helps in intraoperative planning, modification of the surgical steps if required and confirmation of the surgical endpoint in the operating room itself. iOCT was used for the successful management of descemet's membrane detachment (DMD) following deep anterior lamellar keratoplasty (DALK) with intracameral injection of 20% Sulphur hexafluoride. The gas was injected under direct visualization through the microscope with continuous real time monitoring of the change in height of the detached Descemet's membrane (DM). Additionally stab incisions were given through the anterior cornea due to the presence of residual fluid above the DM which was visible on continuous iOCT images. This led to the successful apposition of the DM which otherwise would have remained detached due to the residual fluid. This highlights the importance of continuous iOCT monitoring of the ophthalmic surgical procedures in order to produce a successful anatomical outcome of the surgery without disruption of the surgical procedure.

  18. Methicillin-Resistant Staphylococcus aureus Keratitis after Descemet's Stripping Automated Endothelial Keratoplasty

    PubMed Central

    Miyamoto, Tatsuro; Eguchi, Hiroshi; Tserennadmid, Ehkhmaa; Mitamura-Aizawa, Sayaka; Hotta, Fumika; Mitamura, Yoshinori

    2013-01-01

    Purpose We report a case of methicillin-resistant Staphylococcus aureus (MRSA) keratitis after Descemet's stripping automated endothelial keratoplasty (DSAEK). Case Report An 87-year-old woman who had undergone a DSAEK 4 months previously was referred to Tokushima University Hospital with a diagnosis of infectious keratitis after DSAEK. A white abscess and infiltration in the inferior cornea of the right eye were observed. We started an empiric therapy using topical levofloxacin and chloramphenicol on the basis of the microscopic findings of the corneal scraping concurrently with cultivation of the cornea. Results A strain of MRSA was isolated from the corneal sample. Although the strain was susceptible to chloramphenicol, it was resistant to quinolone. The keratitis improved rapidly due to empiric therapy, and topical steroids could be resumed 6 days after initiation of the empiric therapy. Conclusions To our knowledge, this is the first case of MRSA keratitis, and the second case of bacterial keratitis, after DSAEK. MRSA keratitis can occur following uneventful DSAEK. The empiric therapy on the basis of results from a light microscopic examination of a Gram-stained corneal scraping and restarting topical steroids in the early stages of medication contributed to the good clinical course of this case. PMID:24348415

  19. Optimising deep anterior lamellar keratoplasty (DALK) using intraoperative online optical coherence tomography (iOCT).

    PubMed

    Steven, Philipp; Le Blanc, Carolin; Lankenau, Eva; Krug, Marc; Oelckers, Stefan; Heindl, Ludwig M; Gehlsen, Uta; Huettmann, Gereon; Cursiefen, Claus

    2014-07-01

    To describe the use of intraoperative online optical coherence tomography (iOCT) for improving deep anterior lamellar keratoplasty (DALK) surgery. Retrospective case series of 6 eyes of 6 male patients with keratokonus, corneal dystrophy or herpetic stromal scars undergoing DALK were investigated using intraoperative optical coherence tomography and postsurgical image/video analysis. Main outcome measures were: visibility of surgical steps, especially, assessment of placement depth of injection needle, preparation of bare Descemet's membrane and drainage of interface fluid. iOCT enables real-time visualisation of all surgical steps of DALK procedure in all patients. Placement of air injection needle above Descemet's membrane was reliably monitored as was presence of bare Descemet's membrane and potential interface fluid. iOCT assists with visualisation of injection needle placement and with assessment of bare Descemet's membrane as well as interface fluid during the DALK procedure. Overall iOCT may be a helpful device that supports surgeons in all steps of DALK procedure.

  20. Optimising deep anterior lamellar keratoplasty (DALK) using intraoperative online optical coherence tomography (iOCT)

    PubMed Central

    Steven, Philipp; Le Blanc, Carolin; Lankenau, Eva; Krug, Marc; Oelckers, Stefan; Heindl, Ludwig M; Gehlsen, Uta; Huettmann, Gereon; Cursiefen, Claus

    2014-01-01

    Background/aims To describe the use of intraoperative online optical coherence tomography (iOCT) for improving deep anterior lamellar keratoplasty (DALK) surgery. Methods Retrospective case series of 6 eyes of 6 male patients with keratokonus, corneal dystrophy or herpetic stromal scars undergoing DALK were investigated using intraoperative optical coherence tomography and postsurgical image/video analysis. Main outcome measures were: visibility of surgical steps, especially, assessment of placement depth of injection needle, preparation of bare Descemet's membrane and drainage of interface fluid. Results iOCT enables real-time visualisation of all surgical steps of DALK procedure in all patients. Placement of air injection needle above Descemet's membrane was reliably monitored as was presence of bare Descemet's membrane and potential interface fluid. Conclusions iOCT assists with visualisation of injection needle placement and with assessment of bare Descemet's membrane as well as interface fluid during the DALK procedure. Overall iOCT may be a helpful device that supports surgeons in all steps of DALK procedure. PMID:24590554

  1. Sarnicola air-visco bubble technique in deep anterior lamellar keratoplasty.

    PubMed

    Muftuoglu, Orkun; Toro, Patricia; Hogan, R Nick; Bowman, R Wayne; Cavanagh, H Dwight; McCulley, James P; Mootha, V Vinod; Sarnicola, Vicenzo

    2013-04-01

    The purpose of this study was to describe a new modification for big-bubble deep anterior lamellar keratoplasty (DALK) using pneumatic pressure to detach Descemet membrane (DM) via air injection followed by ophthalmic viscoelastic device (OVD) injection. After failure of big-bubble formation after air injection, OVD was injected from a different site other than the previous air injection using a 27-gauge cannula to detach DM, called air-visco bubble (AVB) DALK technique. The technique was used in 7 human corneoscleral rims that were investigated with anterior segment optical coherence tomography and histopathology and in 69 eyes that underwent DALK surgeries. Big-bubble formation was noted in 4 of 7 of the donor corneoscleral rims. The anterior segment optical coherence tomography showed big-bubble formations together with intrastromal OVD accumulation. The histology of the donor corneas showed microdetachments at the DM in the periphery, deep intrastromal separation, and big-bubble formation filled with OVD. One hundred forty-one of 210 eyes (67%) underwent successful DALK with only air injection, and 69 of 210 eyes (33%) underwent AVB technique when a big bubble was not achieved with only air injection. All the corneas showed a clear interface with good wound healing when DM was bared with the AVB DALK technique. Additional OVD injection to detach DM may be useful in cases where air injection fails. Also, creating small DM detachments with air injection may facilitate the formation of a big bubble with further OVD injection.

  2. Precut cornea for Descemet's stripping endothelial keratoplasty: experience at a single eye bank.

    PubMed

    Mohamed, Ashik; Chaurasia, Sunita; Chandragiri, Venkataswamy; Kandhibanda, Srinivas; Gunnam, Srinivas; Garg, Prashant

    2017-06-01

    The aim of the study is to describe the experience with precut facility for endothelial keratoplasty at a single eye bank affiliated to a tertiary eye care center in India. Data on precut tissues from Nov 2012 to Dec 2014 were retrospectively reviewed from the electronic database of the eye bank of a tertiary eye care center in South India. Donor characteristic data including donor age, precut and postcut endothelial cell density (ECD), recipient age, and thickness of graft were collected. The number of precuts increased from 42 in 2012 (Nov and Dec) and 422 in 2013 to 584 in 2014. Of the total of 1048 precuts, seven (0.67 %) were miscut and could not be utilized for transplants. The donor age ranged from 2 to 89 years. A mean change of 43.6 ± 325.2 cells/mm(2) in ECD was noted after cut, proportional increase in mean being 1.9 %. The change in ECD after cut was negatively correlated with ECD before cut. The recipient age ranged from 1 to 89 years. The median thickness of donor lenticule after cut was 148 µm (interquartile range 131-166 µm). Analysis of precut donor corneas from a single eye bank shows that the ECD of the processed tissues was excellent for transplantation. The tissue wastage in the hands of eye bank personal was minimal.

  3. Deep anterior lamellar keratoplasty of dog eyes using the big-bubble technique

    PubMed Central

    Kim, Soohyun; Kwak, Ji Yoon; Jeong, Manbok

    2016-01-01

    This study was conducted to establish the feasibility of corneal transplantation using the big-bubble technique (BBT) to perform deep anterior lamellar keratoplasty (DALK) in three dogs. After the cornea was trephined 750 µm, 4 mL of air was injected, and the blanched stroma was removed to expose Descemet's membrane (DM). The donor corneal button, which was gently stripped off the DM, was sutured onto the bare DM of the recipient cornea. The dogs received topical antibiotics every 6 h for 7 days and 2% cyclosporine ointment every 12 h for 1 month. The eyes were examined post-operatively at 7, 14, 21, 28 and 150 days. The central portion of the transplanted cornea stayed transparent while corneal haze developed around the transplanted margin. Menace response was normal even though the transplanted cornea was edematous until 3 weeks after surgery. A marginal haze was rarely observed between the donor and recipient corneas at 150 days after the operation. A spotted haze developed in the central part of the deep stroma near the DM. Upon histopathological examination, the stroma and epithelium of the donor cornea had normal structures. Corneal transplantation using DALK with BBT can be performed in dogs preserving the healthy endothelium. PMID:26645335

  4. Enhancing Descemet Membrane Endothelial Keratoplasty in Postvitrectomy Eyes With the Use of Pars Plana Infusion.

    PubMed

    Sorkin, Nir; Einan-Lifshitz, Adi; Ashkenazy, Zach; Boutin, Tanguy; Showail, Mahmood; Borovik, Armand; Alobthani, Murad; Chan, Clara C; Rootman, David S

    2017-03-01

    To present a modified surgical technique to perform Descemet membrane endothelial keratoplasty (DMEK) in previously vitrectomized eyes and to analyze its safety and efficacy. A retrospective analysis of previously vitrectomized eyes that underwent DMEK at Toronto Western Hospital was performed. The modified DMEK technique that was used included placement of a posterior pars plana infusion to reduce fluctuations in the anterior chamber depth and its excessive deepening. Twelve eyes of 12 patients (5 females and 7 males) aged 65.3 ± 21.5 years were included. Mean best-corrected visual acuity improved significantly from 1.72 ± 0.62 logMAR (mean Snellen ∼20/1040) preoperatively to 1.01 ± 0.64 logMAR (mean Snellen ∼20/200) at 6 months postoperatively (P = 0.017). Mean donor endothelial cell density was 2658 ± 229 cells/mm preoperatively and 1732 ± 454 cells/mm at 6 months after the procedure (mean percentage cell loss of 31.8%) (P = 0.046). There were no significant intraoperative complications, and no graft failures. One eye had graft detachment, which resolved after 2 rebubbling procedures. One eye had retinal detachment, which was corrected surgically. The use of posterior pars plana infusion in previously vitrectomized eyes stabilizes the anterior segment during DMEK, allowing for performance of DMEK surgery, and can potentially reduce intraoperative and postoperative complications.

  5. Patch Grafting Using a Cryopreserved Descemet Stripping Automated Endothelial Keratoplasty Flap for Treating Corneal Perforation

    PubMed Central

    Okada, Arisa; Sano, Ichiya; Ikeda, Yoshifumi; Fujihara, Etsuko; Tanito, Masaki

    2016-01-01

    A 73-year-old woman with a corneal perforation of undetermined etiology was treated with corneal patch grafting. A residual partial-thickness corneal button obtained during a previous Descemet stripping automated endothelial keratoplasty (DSAEK) surgery and stored at −80°C in Optisol GS for 3 months was used as a patch graft. Five days postoperatively, the anterior chamber was reformed and the perforation was masked by the donor cornea. During the next several weeks, gradual displacement of the anterior edge of the donor cornea in the limbal direction occurred. Seven weeks postoperatively, further displacement of the donor cornea resulted in unmasking of the perforated area. At this time, the corneal defect was closed by stromal scar tissue and corneal epithelium. Five months postoperatively, best corrected visual acuity was 1.0 without marked astigmatism and intraocular pressure was 9 mm Hg in the left eye. From this case, we learned that cryopreserved DSAEK flaps stored longer than reported previously can be used as patch grafts to treat emergency conditions. Scar tissue can fill a corneal stromal defect 1 mm in diameter during temporary patch grafting for less than 2 months. PMID:27462245

  6. Changes in Anterior, Posterior, and Total Corneal Astigmatism after Descemet Membrane Endothelial Keratoplasty

    PubMed Central

    Zumhagen, Lars; Rosentreter, André; Eter, Nicole

    2017-01-01

    Purpose. To evaluate changes in anterior, posterior, and total corneal astigmatism in patients after Descemet membrane endothelial keratoplasty (DMEK). Methods. We retrospectively included 29 eyes of 23 patients (age 67.6 ± 9.8 years, 13 female, 10 male) after DMEK surgery. The magnitude and axis orientation of anterior, posterior, and total corneal astigmatism before and after DMEK were determined using a rotating Scheimpflug system (Pentacam HR, Oculus). Results. The magnitude of anterior, posterior, and total corneal astigmatism in the central cornea did not change significantly after surgery. Before surgery, we found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Spearman's correlation coefficient (rS) = 0.526, P = 0.003), while after surgery this correlation was no longer significant (rS = 0.038, P = 0.843). There was a significant correlation between the vector difference between preoperative and postoperative posterior astigmatism and the change in corneal pachymetry (rP = 0.47, P = 0.010). Conclusions. Posterior corneal astigmatism (especially the orientation) and therefore the relationship between anterior and total corneal astigmatism may change after DMEK. This should be considered to improve the accuracy of toric IOL power calculations following phakic DMEK or in combined procedures. PMID:28553547

  7. Changes in Anterior, Posterior, and Total Corneal Astigmatism after Descemet Membrane Endothelial Keratoplasty.

    PubMed

    Alnawaiseh, Maged; Zumhagen, Lars; Rosentreter, André; Eter, Nicole

    2017-01-01

    Purpose. To evaluate changes in anterior, posterior, and total corneal astigmatism in patients after Descemet membrane endothelial keratoplasty (DMEK). Methods. We retrospectively included 29 eyes of 23 patients (age 67.6 ± 9.8 years, 13 female, 10 male) after DMEK surgery. The magnitude and axis orientation of anterior, posterior, and total corneal astigmatism before and after DMEK were determined using a rotating Scheimpflug system (Pentacam HR, Oculus). Results. The magnitude of anterior, posterior, and total corneal astigmatism in the central cornea did not change significantly after surgery. Before surgery, we found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Spearman's correlation coefficient (rS) = 0.526, P = 0.003), while after surgery this correlation was no longer significant (rS = 0.038, P = 0.843). There was a significant correlation between the vector difference between preoperative and postoperative posterior astigmatism and the change in corneal pachymetry (rP = 0.47, P = 0.010). Conclusions. Posterior corneal astigmatism (especially the orientation) and therefore the relationship between anterior and total corneal astigmatism may change after DMEK. This should be considered to improve the accuracy of toric IOL power calculations following phakic DMEK or in combined procedures.

  8. Factors associated with graft survival and endothelial cell density after Descemet's stripping automated endothelial keratoplasty.

    PubMed

    Ishii, Nobuhito; Yamaguchi, Takefumi; Yazu, Hiroyuki; Satake, Yoshiyuki; Yoshida, Akitoshi; Shimazaki, Jun

    2016-04-28

    Postoperative endothelial cell loss leads to graft failure after corneal transplantation, and is one of the important issues for long-term prognosis. The objective of this study was to identify clinical factors affecting graft survival and postoperative endothelial cell density (ECD) after Descemet's stripping automated endothelial keratoplasty (DSAEK). A total of 198 consecutive Japanese patients (225 eyes) who underwent DSAEK were analysed using Cox proportional hazard regression and multiple linear regression models. The candidate factors included recipient age; gender; diagnosis; pre-existing iris damage state, scored based on its severity; the number of previous intraocular surgeries; graft ECD; graft diameter; simultaneous cataract surgery; surgeons experience; intraoperative iris damage; postoperative rebubbling; and graft rejection. Eyes with higher pre-existing iris damage score and more number of previous intraocular surgery had a significantly higher risk of graft failure (HR = 8.53; P < 0.0001, and HR = 2.66; P = 0.026, respectively). Higher pre-existing iris damage score, lower graft ECD, and smaller graft diameter were identified as significant predisposing factors for lower postoperative ECD. The results show that iris damage status before DSAEK may be clinically useful in predicting the postoperative course. Avoiding intraoperative iris damage, especially in eyes with low ECD can change the prognosis of future DSAEK.

  9. Techniques for Learning Descemet Membrane Endothelial Keratoplasty for Eyes of Asian Patients With Shallow Anterior Chamber.

    PubMed

    Hayashi, Takahiko; Oyakawa, Itaru; Kato, Naoko

    2017-03-01

    To describe several essential surgical techniques that overcome difficulties in performing Descemet membrane endothelial keratoplasty (DMEK) for inexperienced surgeons, especially those who perform DMEK on eyes of Asian patients. Nine eyes of 9 Asian patients with bullous keratopathy who underwent DMEK were analyzed retrospectively. All patients were given a diuretic such as D-mannitol or acetazolamide shortly before surgery, with retrobulbar anesthesia and a Nadbath facial nerve block. Core vitrectomy before DMEK was performed in several cases in which a high vitreous pressure during surgery was predicted. The donor graft was stained with trypan blue, and a 25-G anterior chamber maintenance cannula was used to maintain the anterior chamber depth during graft insertion in all eyes. The cornea became clear in all eyes. The best spectacle-corrected visual acuity had improved significantly 6 months after the surgery compared with preoperative values (P = 0.026). The corneal endothelial cell density was 1371 cells per square millimeter at postoperative 6 months. Although DMEK is technically difficult, especially for inexperienced surgeons who operate on eyes of Asian patients, controlling anterior chamber pressure using various manipulations may help to prevent iatrogenic primary graft failure and lead to successful DMEK.

  10. Spontaneous resolution of double anterior chamber with perforation of Descemet's membrane in deep anterior lamellar keratoplasty.

    PubMed

    Venkatraman, Arvind

    2012-05-01

    Deep anterior lamellar keratoplasty (DALK) using Dr. Anwar's big bubble technique was performed for a patient with granular dystrophy. Intraoperatively, a perforation of the Descemet's membrane (DM) was noted inferonasally. Though the surgery was completed, the donor graft appeared to have an intact endothelium, which was inadvertently left behind by the surgeon. Intraoperatively, there was a perforation of inferonasal DM and surgery was completed by inadvertently placing a donor with an intact endothelium. Postoperatively the patient presented with a complete DM detachment and a resultant double anterior chamber (DAC). In spite of two attempts at an air tamponade on the first and fifth post operative days, the DAC still persisted. Surprisingly, during the 6(th) week follow up visit, there was a complete resolution of the DAC as well as total recovery of vision. This interesting case clearly exemplifies that, in spite of failed attempts at air tamponade, a DM detachment and a DAC due to DM perforation following a DALK procedure can resolve spontaneously with good visual outcome.

  11. Modeling for radio-frequency conductive keratoplasty: implications for the maximum temperature reached in the cornea.

    PubMed

    Berjano, Enrique J; Alió, Jorge L; Saiz, Javier

    2005-06-01

    Conductive keratoplasty (CK) is a new surgical technique for steepening the contours of the cornea to reduce hyperopia. It has been emphasized that during CK, tissue resistance to radio-frequency electrical current flow generates a localized heat with temperatures between 65 and 75 degrees C; however, we hypothesize that the maximum temperature reached in the cornea may be higher. For this reason, we developed a finite-element model to estimate the temperature distributions in the cornea during CK. The time evolution of the impedance obtained from computer simulations was compared to that obtained in an experimental study previously published. Our results show that during a typical CK with a 60% setting power (equivalent to 200 V peak-to-peak), the cornea may reach temperatures over 100 degrees C at the electrode tip. On the other hand, the initial impedance of the cornea has a significant influence on the temperature distribution, while the initial temperature of the cornea is not a significant parameter. The results also suggest that low power settings (30-40%) do not produce temperatures over 100 degrees C. Finally, although the actual voltage waveform during CK is exponential and pulsed, our model based on a constant voltage (with a value equal to the root mean square value) provides a better agreement between the theoretical impedance time evolution and that obtained experimentally.

  12. Fourier transform infrared analysis of the thermal modification of human cornea tissue during conductive keratoplasty.

    PubMed

    Zhang, Li; Aksan, Alptekin

    2010-01-01

    This paper presents a study using in vitro Fourier transform infrared spectroscopy (FT-IR) analysis to determine the thermal damage induced to the human cornea by the conductive keratoplasty (CK) procedure. Human cornea tissues were treated with CK at different radiofrequency power (58-64%) and pulse duration (0.6-1.0 s) settings. The cornea tissues were cryo-sectioned and FT-IR analysis was performed to detect the extent of thermal damage by the second-derivative analysis of the infrared (IR) spectral bands corresponding to protein secondary structure. The protein amide I and II spectral bands measured in vitro mainly arose from collagen. The denatured cornea tissue showed a higher beta-sheet content than the native tissue. The extent of the thermal damage created by the CK treatment depended on power and duration settings, with the latter having a stronger effect. With clinical settings (60%, 0.6 s), the thermal damage area was confined within a radius of 100 microm. CK treatment duration had a more significant effect on the damage zone than the power setting.

  13. Factors Predicting Refractive Outcomes After Deep Anterior Lamellar Keratoplasty in Keratoconus.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad Ali

    2015-10-01

    To determine the factors that predict refraction, mean keratometry, and keratometric astigmatism after deep anterior lamellar keratoplasty (DALK) in keratoconus. Consecutive interventional case series. This study enrolled 194 consecutive eyes of 181 patients with keratoconus who underwent DALK using the big-bubble technique. Indications for surgery included contact lens intolerance or poor corrected visual acuity. Univariate analyses and analysis of covariance were used to investigate recipient-, surgical-, and postoperative-related variables capable of predicting refractive outcomes, including mean keratometry, keratometric astigmatism, and spherical equivalent refraction. The mean patient age was 27.9 ± 8.2 years, and the patients were followed for 35.9 ± 18.2 months postoperatively. Preoperative mean keratometry (P = .007), time interval from surgery to running suture removal (P = .01), and suture-tract vascularization (P = .04) significantly influenced postoperative mean keratometry. Vitreous length predicted postoperative spherical equivalent (P = .03). Postoperative keratometric astigmatism failed to demonstrate any significant correlation with the preoperative, surgical, and postoperative variables. Postoperative refractive outcomes did not change relative to patient age and sex, central and peripheral corneal thickness, recipient trephination size, surgical technique (big-bubble vs manual dissection DALK), duration of steroid administration, and elevated intraocular pressure. Keratoconus patients with an elongated posterior segment and/or steep corneas should be informed of the need for postoperative optical correction after DALK. Running suture removal should be postponed for as long as possible if there is no suture-related complication. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Femtosecond laser and microkeratome-assisted Descemet stripping endothelial keratoplasty: first clinical results.

    PubMed

    Rosa, Andreia Martins; Silva, Maria Fátima; Quadrado, Maria João; Costa, Esmeralda; Marques, Inês; Murta, Joaquim Neto

    2013-09-01

    To perform Descemet stripping automated endothelial keratoplasty (DSAEK) using a novel technique to obtain very thin (<100 µm) posterior corneal disks. Twenty five DSAEK grafts were prepared with two sequential cuts: the first cut, of variable thickness, was made with a femtosecond laser and the second with a 300 µm microkeratome head. Spectacle corrected visual acuity, endothelial cell density evaluation with specular microscopy and anterior segment optical coherence tomography to measure central and peripheral graft thickness was performed preoperatively and postoperatively at 1, 3 and 6 months. There were no irregular cuts or perforations during tissue preparation. Central graft thickness was 79.6 µm (SD ± 14.5; range 54-98) and 69.3 µm (SD ± 14.2; range 49-96) at 3 and 6 months. Corrected distance visual acuity improved from 0.91 logMAR preoperatively to 0.11 logMAR at 6 months. Donor endothelial cells averaged 2675 cells/mm(2) preoperatively and 1729 cells/mm(2) at 6 months. There were no graft detachments. This new technique consistently yielded very thin grafts (<100 µm), excellent visual acuity results and good endothelial cell counts. No donor tissue was wasted.

  15. Pupillary Abnormalities in Descemet Membrane Endothelial Keratoplasty After Nearly Full Tamponade.

    PubMed

    Arnalich-Montiel, Francisco; Pérez-Sarriegui, Ane; Lauzirika, Gorka; Porrua, Laura; Hernández-Verdejo, José Luis

    2017-03-01

    To describe the incidence, risk factors, and management of pupillary abnormalities after anterior chamber (AC) full air or gas tamponade in Descemet membrane endothelial keratoplasty (DMEK) without pupillary block. In this retrospective case series, clinical records of 25 patients (32 eyes) who underwent DMEK were reviewed for pupillary abnormalities and iris morphology. All patients had nearly full intracameral tamponade with air or 20% SF6 at the end of surgery without default air release postoperatively. Pupillary abnormalities ranging from mild ovalization to mid-mydriasis were seen in 56% of the cases. These abnormalities were not related to morphometric changes in the iris volume, or in the iris dilator or iris sphincter muscle, but were probably due to posterior synechiae. Combining DMEK and cataract surgery increases by 5-fold the odds of developing this complication. Surgical revision of the posterior surface of the iris and synechiolysis reversed these pupillary abnormalities. Nonischemic pupillary abnormalities can be seen in patients with DMEK using a nearly full air/gas tamponade in the AC after surgery despite patent iridectomy especially when combined with cataract surgery. Ensuring complete mydriasis in the immediate postoperative period and a free-floating bubble in the AC above the inferior pupillary margin may reduce its incidence.

  16. Histopathological changes after deep anterior lamellar keratoplasty using the 'big-bubble technique'.

    PubMed

    Braun, Joachim M; Hofmann-Rummelt, Carmen; Schlötzer-Schrehardt, Ursula; Kruse, Friedrich E; Cursiefen, Claus

    2013-02-01

    During deep anterior lamellar keratoplasty (DALK), endothelium and Descemet's membrane are separated from the corneal stroma by intrastromal air injection ('big-bubble technique'). The aim of our study is to analyse histopathological changes in host corneal tissue caused by air insufflation in patients with keratoconus, their variability in 10 patients and their possible clinical implication. The excised anterior corneal lamellae of 10 patients with keratoconus having undergone DALK using the 'big-bubble technique' were analysed by light and transmission electron microscopy as well as immunohistochemistry. In addition, intrastromal air accumulations were quantified morphometrically. Intrastromal air was detected in all examined excised lamellae (8% of stromal volume), but with large variability (SD 8.8). It was detected preferentially in the inner layer of the corneal stroma and represented there up to 39% of the stromal volume. In addition, the air was predominantly located at one periphery of the excised lamellae. Intrastromal air bubbles were larger in the inner than in the superficial stromal layer and characterized by round shape and a CD68-negative collagenous 'pseudocapsule'. We detected no air-injection-induced alterations in Bowman's layer and epithelium. Our results show that 'big-bubble DALK' causes significant intrastromal air accumulations in the cornea. Pathologists should be conscious of this phenomenon and the high topographic variability. Intrastromal air in the recipient rim may be accompanied by a decrease in mechanical stability and could contribute to postoperative suture loosening. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

  17. Air bubble-associated endothelial trauma in descemet stripping automated endothelial keratoplasty.

    PubMed

    Hong, Anna; Caldwell, Matthew C; Kuo, Anthony N; Afshari, Natalie A

    2009-08-01

    To evaluate endothelial cell trauma by anterior chamber (AC) air bubbles in Descemet stripping automated endothelial keratoplasty (DSAEK). Laboratory investigation. Twelve human donor corneas (6 pairs) were sectioned using an automated microkeratome system (Moria ALTK System, Antony, France). One cornea of each pair was mounted on a Moria artificial AC, and an air bubble was injected to fill 40% of the AC. The apparatus was rotated 180 degrees for a total of 50 times to simulate air bubble trauma. The fellow corneas were used as controls. Each endothelial graft was stained with 0.25% Trypan blue for 90 seconds followed by 0.2% alizarin red for 2 minutes, and digital photomicrographs were obtained. Abnormally staining areas indicative of graft injury were removed digitally from the total graft area. The proportion of uninjured corneal endothelium was calculated, and differences were analyzed. In this ex vivo model of air bubble trauma, the proportion of viable graft endothelium after air bubble injury was 79.8 +/- 0.04% (n = 6). The proportion of viable endothelium in the control group was 89.9 +/- 0.02% (n = 6). The statistically significant mean difference of 10.1% (P = .03) is indicative of greater endothelial injury after air bubble trauma. Using this model, a moderate but significant amount of endothelial cell damage was associated with air bubble trauma compared with the control group. Air bubble trauma may account partially for the loss of endothelial cell density after DSAEK surgery and may impact graft survival.

  18. Incidence of cystoid macular edema after Descemet's stripping automated endothelial keratoplasty.

    PubMed

    Pedemonte-Sarrias, Eduard; Salvador Playà, Toni; Sassot Cladera, Irene; Gris, Oscar; Ribas Martínez, Joan; García-Arumí, José; Giménez, Núria

    2017-01-01

    To determine the incidence of cystoid macular edema (CME) after Descemet's stripping automated endothelial keratoplasty (DSAEK). This study included all consecutive patients operated in a Spanish tertiary reference hospital over a period of four years. A total of 55 eyes from 47 patients matched the selection criteria. CME was diagnosed clinically at the slit-lamp and confirmed by optical coherence tomography. Six cases of CME were diagnosed postoperatively, which represented an incidence of 11%. Three patients had previously undergone DSAEK alone (7%; 3/41) and the other three, DSAEK combined with phacoemulsification (21%; 3/14). Five out of six patients with CME responded to standard therapy. CME is a possible complication after DSAEK and can be treated with standard therapy. CME appears more frequently when DSAEK is combined with phacoemulsification and posterior chamber (PC) intraocular lens (IOL) implantation. Intraoperative damage to the corneal endothelial cells might play a role in the pathogenesis of CME. As long as the causes remain unclear, we recommend administering prophylaxis when risk factors are present or when combined surgery is planned.

  19. One-year outcome after Descemet membrane endothelial keratoplasty (DMEK) comparing sulfur hexafluoride (SF6) 20% versus 100% air for anterior chamber tamponade.

    PubMed

    Schaub, Friederike; Enders, Philip; Snijders, Katharina; Schrittenlocher, Silvia; Siebelmann, Sebastian; Heindl, Ludwig M; Bachmann, Björn O; Cursiefen, Claus

    2017-07-01

    To investigate 1-year clinical outcome and complication rates following Descemet membrane endothelial keratoplasty (DMEK) with sulfur hexafluoride 20% (SF620%) anterior chamber tamponade compared with conventionally used 100% air for primary graft attachment during DMEK surgery. Records of 1112 consecutive DMEKs were reviewed retrospectively and grouped by anterior chamber tamponade used during DMEK surgery (SF620% vs 100% air). Outcome measures included intraocular pressure (IOP), best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD) and central corneal thickness (CCT) at 1, 3, 6 and 12 months after DMEK surgery. Complication rates were assessed, including intraoperative and postoperative complications, and graft detachment rate requiring rebubbling. A total of 854 cases were included in this study. In 105 cases (12.3%), DMEK was performed with SF620%, and in 749 cases (87.7%) 100% air was used for anterior chamber tamponade. Outcome results for IOP, BSCVA, ECD and CCT at all follow-up time points were comparable for both anterior chamber tamponade groups without statistical significant differences (p≥0.05), but graft detachment rate requiring rebubbling was significantly lower in the SF620% group (p<0.001). Whereas SF620% anterior chamber tamponade does not seem to negatively affect the clinical outcome of DMEK surgery within the first postoperative year, use of SF620% significantly reduces the rate of rebubblings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Projectile penetration into ballistic gelatin.

    PubMed

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (<120m/s). The results of sphere penetration depth versus projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. © 2013 Published by Elsevier Ltd.

  1. Evaluation of Microencapsulated Penetrant Inspection.

    DTIC Science & Technology

    1980-12-01

    AD-A9b 826 GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE GROUP F/6 IA/2ADG EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION.(U) DEC 80 J M...4156 ADA096826 EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION i :I J.M. Portaz Aircraft Engine Group General Electric Company Cincinnati, Ohio... Microencapsulated Penetrant 5 7riJF-Iehica17 = Inspection p un May@84 -1 ---- --- ---- 19AMFGK657j7 7. AiJTHOR(s) nVCWRACT OR GRANT m 𔃻 " JO J.M./Portaz

  2. THE KINETICS OF PENETRATION

    PubMed Central

    Osterhout, W. J. V.; Kamerling, S. E.

    1934-01-01

    A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external

  3. LeciPlex, invasomes, and liposomes: A skin penetration study.

    PubMed

    Shah, Sanket M; Ashtikar, Mukul; Jain, Ankitkumar S; Makhija, Dinesh T; Nikam, Yuvraj; Gude, Rajiv P; Steiniger, Frank; Jagtap, Aarti A; Nagarsenker, Mangal S; Fahr, Alfred

    2015-07-25

    The present study compares three vesicular systems, cationic LeciPlex, invasomes, and conventional liposomes for their ability to deliver drugs deep into the skin. Skin penetration ability of the three vesicular systems was studied for two drugs namely idebenone (antioxidant/anticancer) and azelaic acid (antiacne). All systems showed sizes in nanometer range with small polydispersity indices. Vesicular systems were characterized by CryoTEM studies to understand the differences in morphology of the vesicular systems. Ex vivo human skin penetration studies suggested a pattern in penetration of drugs in different layers of the skin: LeciPlex showed higher penetration for idebenone whereas invasomes showed higher penetration of azelaic acid. Ex vivo study using a fluorescent dye (DiI) was performed to understand the differences in the penetration behavior of the three vesicular systems on excised human skin. In vitro cytotoxicity studies on B16F10 melanoma cell lines revealed, when loaded with idebenone, LeciPlex formulations had the superior activity followed by invasomes and liposomes. In vitro antimicrobial study of azelaic acid loaded systems on Propionibacterium acne revealed high antimicrobial activity for DDAB leciplex followed by almost equal activity for invasomes and CTAB LeciPlex followed by liposomes. Whereas antiacne efficacy study in rats for azelaic acid loaded systems, invasomes exhibited the best antiacne efficacy followed by liposomes and LeciPlex. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  5. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  6. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  7. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

  8. Penetration through the Skin Barrier.

    PubMed

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates. During recent decades, the latter has received increased attention as a route for intentionally delivering drugs to patients. This has stimulated research in methods for sampling, measuring and predicting percutaneous penetration. Previous chapters have described how different endogenous, genetic and exogenous factors may affect barrier characteristics. The present chapter introduces the theory for barrier penetration (Fick's law), and describes and discusses different methods for measuring the kinetics of percutaneous penetration of chemicals, including in vitro methods (static and flow-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous penetration. Finally, a short discussion of the advantages and challenges of each method is provided, which will hopefully allow the reader to improve decision making and treatment planning, as well as the evaluation of experimental studies of percutaneous penetration of chemicals. © 2016 S. Karger AG, Basel.

  9. THE PENETRATION OF STRONG ELECTROLYTES

    PubMed Central

    Cooper, W. C.; Dorcas, M. J.; Osterhout, W. J. V.

    1929-01-01

    The entrance of strong electrolytes into Valonia is very slow unless the cells are injured. This, together with the very high electrical resistance of the protoplasm, suggests that they may penetrate largely as undissociated molecules formed at the surface of the protoplasm by the collision of ions. Under favorable circumstances KCl may be absorbed to the extent of 3 x 10–8 mols per hour per sq. cm. of surface together with about 0.17 as much NaCl. Other substances which seem to penetrate to some extent are Li, Rb, Br, BrO3, I, IO3, and selenite. Little or no penetration is shown by SCN, ferricyanide, ferrocyanide, formate, salicylate, tungstate, seleniate, NO2, SO3, Sb, glycerophosphate, and many heavy metals and the alkaline earths. In sea water whose specific gravity had been increased by CsCl cells of Valonia floated for over a year and there was little or no penetration of Cs except as the result of injury. The penetration of NH4Cl decreases the specific gravity of the sap and causes the cells to float: under these circumstances they live indefinitely. It is probable that NH3 or NH4OH penetrates and is subsequently changed to NH4Cl. It would seem that if the sea contained a little more ammonia this would be a floating organism. PMID:19872471

  10. Is Color Experience Cognitively Penetrable?

    PubMed

    Brogaard, Berit; Gatzia, Dimitria E

    2017-01-01

    Is color experience cognitively penetrable? Some philosophers have recently argued that it is. In this paper, we take issue with the claim that color experience is cognitively penetrable. We argue that the notion of cognitive penetration that has recently dominated the literature is flawed since it fails to distinguish between the modulation of perceptual content by non-perceptual principles and genuine cognitive penetration. We use this distinction to show that studies suggesting that color experience can be modulated by factors of the cognitive system do not establish that color experience is cognitively penetrable. Additionally, we argue that even if color experience turns out to be modulated by color-related beliefs and knowledge beyond non-perceptual principles, it does not follow that color experience is cognitively penetrable since the experiences of determinate hues involve post-perceptual processes. We conclude with a brief discussion of the implications that these ideas may have on debates in philosophy. Copyright © 2016 Cognitive Science Society, Inc.

  11. Corrosion casts of big bubbles formed during deep anterior lamellar keratoplasty.

    PubMed

    Feizi, Sepehr; Kanavi, Mozhgan Rezaei; Kharaghani, Davood; Balagholi, Sahar; Meskinfam, Masoumeh; Javadi, Mohammad Ali

    2016-11-01

    To characterize the walls of big bubbles formed during deep anterior lamellar keratoplasty (DALK) using the corrosion casting technique. Fresh corneoscleral buttons with normal transparency and without any known eye diseases (n = 11) were obtained from 11 human donors. A 20-gauge needle was used to inject a solution of 20 % polyvinyl alcohol (PVA) immediately beneath the corneal endothelium to form big bubbles in eight corneoscleral buttons. In the second experiment on three corneoscleral buttons, a big bubble was first formed by air injection beneath the endothelium. Thereafter, 20 % PVA was injected into the bubble space. Scanning electron microscopy was used to characterize the surfaces of the casts, which replicated the walls of the big bubbles. A type-1 bubble was formed in all corneas. In one cornea, one type-1 bubble was initially formed centrally, and while it was enlarged, an eccentric type-2 bubble appeared. Scanning electron microscopy showed that the casts of type-1 bubbles had two distinct surfaces. The anterior surface demonstrated several holes or pits, depending on the material used for the bubble formation, whereas the posterior surface exhibited an uneven surface. The anterior and posterior surfaces of the type-2 cast were more or less similar. A communication measuring 531.9 µm in length and 171.4 µm in diameter was found between the two bubbles. The corrosion casting technique provides a permanent three-dimensional record of the potential spaces and barriers in the posterior corneal stroma, which explains several features associated with big-bubble DALK.

  12. Histopathologic Features of Descemet Membrane Endothelial Keratoplasty Graft Remnants, Folds, and Detachments.

    PubMed

    Müller, Thomas M; Verdijk, Robert M; Lavy, Itay; Bruinsma, Marieke; Parker, Jack; Binder, Perry S; Melles, Gerrit R J

    2016-12-01

    To describe the histologic features of postmortem eyes after Descemet membrane endothelial keratoplasty (DMEK) and their potential clinical implications. Histopathologic study. Eleven postmortem DMEK corneas of 8 patients who underwent surgery for Fuchs endothelial dystrophy, with an average postoperative time of 4±1.9 years (range, 7 months-6.5 years). Eleven corneas transplanted with a DMEK graft were procured after death and processed for light microscopy evaluation. Histologic findings at the donor-host interface and at the host edge. Of the 11 corneas available for analysis, 9 showed normal anatomic features in the corneal center; that is, the donor-host interface resembled that of a virgin eye. One eye also had an anatomically normal periphery, but the remaining 10 eyes showed specific abnormalities in the periphery. Nine demonstrated overlapping of the DMEK graft onto the host edge of the descemetorhexis (and in 6 of these, the overlapping tissue showed a contracted inward fold at its peripheral edge with scar tissue); 1 eye showed a dense, acellular scar overlying a portion of the DMEK graft that clinically had shown a detachment followed by spontaneous adherence; 3 eyes showed subtle graft folds with scar tissue anteriorly; in 2 eyes (of the same patient), the anterior banded layer of the host Descemet membrane (DM) was still in situ across the cornea (both of these eyes had required rebubbling); and 2 eyes showed host DM remnants within the corneolimbal tunnel incision that may have interfered with incisional wound healing. Incomplete host DM removal may relate to postoperative DMEK graft detachment and wound instability. Graft detachments may reattach with interface scarring. Rebubbling procedures may be performed within 4 to 6 weeks, before portions of the detached graft scar. Subtle DMEK graft folds may explain subjective reports of monocular diplopia. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  13. Standardization of the Descemet membrane endothelial keratoplasty technique: Outcomes of the first 450 consecutive cases.

    PubMed

    Satué, M; Rodríguez-Calvo-de-Mora, M; Naveiras, M; Cabrerizo, J; Dapena, I; Melles, G R J

    2015-08-01

    To evaluate the clinical outcome of the first 450 consecutive cases after Descemet membrane endothelial keratoplasty (DMEK), as well as the effect of standardization of the technique. Comparison between 3 groups: Group I: (cases 1-125), as the extended learning curve; Group II: (cases 126-250), transition to technique standardization; Group III: (cases 251-450), surgery with standardized technique. Best corrected visual acuity, endothelial cell density, pachymetry and intra- and postoperative complications were evaluated before, and 1, 3 and 6 months after DMEK. At 6 months after surgery, 79% of eyes reached a best corrected visual acuity of≥0.8 and 43%≥1.0. Mean preoperative endothelial cell density was 2,530±220 cells/mm2 and 1,613±495 at 6 months after surgery. Mean pachymetry measured 668±92 μm and 526±46 μm pre- and (6 months) postoperatively, respectively. There were no significant differences in best corrected visual acuity, endothelial cell density and pachymetry between the 3 groups (P > .05). Graft detachment presented in 17.3% of the eyes. The detachment rate declined from 24% to 12%, and the rate of secondary surgeries from 9.6% to 3.5%, from group I to III respectively. Visual outcomes and endothelial cell density after DMEK are independent of the technique standardization. However, technique standardization may have contributed to a lower graft detachment rate and a relatively low number of secondary interventions required. As such, DMEK may become the first choice of treatment in corneal endothelial disease. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  14. Factors influencing big-bubble formation during deep anterior lamellar keratoplasty in keratoconus.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad Ali; Daryabari, Seyed-Hashem

    2016-05-01

    To investigate recipient and operative factors that can influence the rate of achieving a bare Descemet's membrane (DM) during deep anterior lamellar keratoplasty (DALK) for keratoconus. In this retrospective comparative study, a total of 290 (153 right) consecutive eyes from 257 (179 male) keratoconus-affected patients who underwent DALK with the big-bubble technique were enrolled. Univariate analyses and multiple logistic regressions were used to investigate factors including patient age and sex, family history of keratoconus, history of contact lens wear or vernal keratoconjunctivitis, the presence of Vogt's striae or superficial stromal opacities, keratometric readings, corneal diameter, central and peripheral corneal thickness, anterior chamber depth, vitreous length, and trephination size, which could predict achievement of a bare DM. The surgery was completed as a DALK in 289 of 290 eyes, and a bare DM was successfully achieved in 229 (79.2%) eyes. The recipient sex and trephination size significantly influenced the success rate of big-bubble formation. Females had decreased odds of achieving a bare DM by 0.44 times (p=0.02). For each 0.1 mm increase in the trephination size, the odds of a successful big-bubble formation increased by 1.36 times (p=0.03). Other investigated factors did not significantly influence the rate of achieving a bare DM. The rate of successful big-bubble formation was 79.2% in keratoconus. Among the different factors, recipient sex and trephination size significantly influenced this rate. Females had a lower probability of big-bubble formation, and a large trephination size was associated with an increase in the probability of achieving a bare DM. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. Incidence and Risk Factors of Elevated Intraocular Pressure Following Deep Anterior Lamellar Keratoplasty.

    PubMed

    Huang, Olivia S; Mehta, Jodhbir S; Htoon, Hla M; Tan, Donald T; Wong, Tina T

    2016-10-01

    To report the incidence and risk factors of elevated IOP following deep anterior lamellar keratoplasty (DALK). A retrospective case series. A retrospective study investigating the 5-year incidence of raised IOP following DALK cases performed from 2004 to 2008 in a tertiary center. Patients with less than 6 months of follow-up were excluded. Elevated IOP was defined as IOP >21 mm Hg. An episode of elevated IOP occurred in 36.1% of cases (44/122 cases), 11.4% (n = 5) occurring within the first week. The average duration of raised IOP was 48.9 (SD: 65.5) days. Causes included pupil block from air, swollen grafts, and corticosteroid response. Surgical intervention to lower IOP was required in 3 cases (6.8%). In multivariate analyses, the use of Olopatadine 0.1% or cyclosporine eye drops before DALK (OR = 14.51, 95% CI = 1.43-147.23) and use of topical prednisolone acetate 1% compared with dexamethasone 0.1% post DALK (OR = 4.79, 95% CI = 0.73-31.52) were associated with higher rates of elevated IOP post DALK. At 5 years post DALK, 3 of 71 cases (4.48%) developed de novo glaucomatous field defects, and 1 case with pre-existing glaucoma had progression of glaucomatous field defect. DALK was associated with a significant incidence of transiently elevated IOP postoperatively, but had a low incidence of de novo glaucoma at 5 years in our study. Risk factors for raised IOP post DALK included the use of topical prednisolone acetate 1% compared with dexamethasone 0.1%, and the use of Olopatadine 0.1% or any concentration of cyclosporine eye drops prior to DALK. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Optimising keratoplasty for Peters' anomaly in infants using spectral-domain optical coherence tomography.

    PubMed

    Hong, Jiaxu; Yang, Yujing; Cursiefen, Claus; Mashaghi, Alireza; Wu, Dan; Liu, Zuguo; Sun, Xinghuai; Dana, Reza; Xu, Jianjiang

    2017-06-01

    To present in vivo anterior segment optical coherence tomography (OCT) features of infants with Peters' anomaly obtained during presurgical examination under general anaesthesia, and to evaluate the impact of OCT features on surgical decision making. This is a single-centre, consecutive, observational case series including 44 eyes of 27 infants with Peters' anomaly (5-18 months) undergoing keratoplasty. Medical records of patients were reviewed retrospectively. Clinical features and OCT findings, along with their impact on surgical decision-making were analysed. Of 27 patients, 10 had unilateral and 17 had bilateral disease. Two patients with mild disease (three eyes) had a posterior corneal defect with leukoma (2/27, 7.4%). Twenty patients (32 eyes) with iridocorneal adhesions were classified as having moderate Peters' anomaly (20/27, 74.1%) and five patients (nine eyes) with lenticulocorneal adhesions were classified as having severe Peters' anomaly (5/27, 18.5%). The range of angle closure, anterior chamber depth and maximum iridocorneal adhesion length (all p<0.001) were significantly different among groups, indicating that they might serve as novel OCT parameters for assessing the severity of Peters' anomaly. The surgical approach in seven patients (21.2%) was altered in response to intraoperative OCT findings, which provided information regarding the anatomical structure of the anterior chamber not provided by the surgical microscope. The use of OCT prevented unnecessary cataract surgeries in five patients. Our study showed that information gained from OCT under anaesthesia allows surgeons to classify type and severity of Peters' anomaly and supports surgical decision making. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. A Novel Tectonic Keratoplasty with Femtosecond Laser Intrastromal Lenticule for Corneal Ulcer and Perforation.

    PubMed

    Jiang, Yang; Li, Ying; Liu, Xiao-Wei; Xu, Jing

    2016-08-05

    Small incision refractive lenticule extraction (SMILE) is an effective laser procedure that treats myopia. This research was to describe a novel approach to treat corneal ulcer or perforation using the corneal lenticules obtained from SMILE and to evaluate the safety and effectiveness of tectonic keratoplasty with femtosecond laser intrastromal lenticule (TEKIL). A total of twenty patients (22 eyes) were monitored for at least 6 months and were assessed using slit lamp microscopy, optical coherence tomography, and best-corrected visual acuity (BCVA). Postoperative complications throughout the study period were recorded. Corneal ulcer in 14 patients (16 eyes) and corneal perforation in six patients (6 eyes) were treated with TEKIL. The patients were ten females and ten males, with a mean age of 58.5 ± 16.3 years (range: 16-81 years). In this study, the most causes of corneal ulcer or perforation were immunologic causes (54.5%). After TEKIL procedure, global integrity was achieved in all cases. No immune rejection or perforation was detected. The mean BCVA improved from 0.17 ± 0.20 preoperatively to 0.27 ± 0.25 postoperatively at the final follow-up (t = 2.095, P = 0.052). The postoperative BCVA improved in 12 eyes (54.5%) and maintained in nine eyes (40.9%). Vision function successfully maintained in all eyes (100%). In three cases, corneal ulcers were treated by reoperation of TEKIL at 3 months after the initial surgery for the reason that the residual corneal thickness was <250 μm. TEKIL seems to be an effective treatment for corneal ulcer and perforation in the condition of emergency and donor shortage.

  18. Big-bubble deep anterior lamellar keratoplasty using central vs peripheral air injection: a clinical trial.

    PubMed

    Feizi, Sepehr; Daryabari, Seyed-Hashem; Najdi, Danial; Javadi, Mohammad Ali; Karimian, Farid

    2016-06-10

    To compare 2 sites of air injection to achieve Descemet membrane (DM) detachment in big-bubble deep anterior lamellar keratoplasty (DALK). In this prospective, randomized study, 48 eyes of 48 keratoconus-affected patients who underwent DALK by cornea fellows were enrolled. Each patient was randomly assigned into one of 2 groups. After trephination to approximately 80% of the corneal thickness, a 27-G needle was inserted into the stroma from the trephination site. The needle was moved radially inside the trephination site and advanced to the central or paracentral cornea in group 1. In group 2, the needle was inserted into the deep stroma from the trephination site and advanced into the peripheral cornea to approximately 1.5 mm anterior to the limbus. Air was gently injected into the deep stroma until a big bubble was formed. The rates of DM separation and complications were compared between the 2 groups. Big-bubble formation was successful in 79.2% of the eyes in the study group. A bare DM was achieved by central injection in 68.0% of group 1 and by peripheral injection in 69.6% of group 2 (p = 0.68). This rate was increased to 80.0% and 78.3% in groups 1 and 2, respectively, after the injection site was shifted when injections failed. The study groups were comparable in terms of complications including DM perforation and bubble bursting. Both injection sites were equivalent in their rates of big-bubble formation and complications. Less experienced surgeons are advised to initially inject air outside the trephination.

  19. Bubble technique for Descemet membrane endothelial keratoplasty tissue preparation in an eye bank: air or liquid?

    PubMed

    Ruzza, Alessandro; Parekh, Mohit; Salvalaio, Gianni; Ferrari, Stefano; Camposampiero, Davide; Amoureux, Marie-Claude; Busin, Massimo; Ponzin, Diego

    2015-03-01

    To compare the big-bubble method using air and liquid as medium of separation for Descemet membrane endothelial keratoplasty (DMEK) lenticule preparation in an eye bank. Donor corneas (n=20) were immersed in liquid [tissue culture medium (TCM)]. Air and liquid was injected using a 25-gauge needle in the posterior stroma or as near to the stroma-Descemet membrane (DM) phase as possible to create a complete bubble of larger diameter. The endothelial cell density and mortality were checked pre- and postbubble after deflating the tissue. Four pairs of tissues were used to analyse the intracellular tight junctions and three pairs for histological examination and DNA integrity studies, respectively. The yield obtained using air was 80%, whereas that with liquid was 100%. Single injection was required in six cases; twice in two cases; three and four times in one case each with air bubble, whereas seven cases required single injection; twice in two cases; and thrice in just one case with liquid bubble. The average diameter of the final lenticule was 9.12 (±1.71) mm for air bubble and 9.78 (±1.75) mm for liquid bubble with p=0.4362 (no statistical significance). Endothelial cell mortality postbubble preparation was 8.9 (±12.38)% for air and 6.25 (±9.57)% for liquid (p=0.6268). DM and endothelium could be separated exclusively using air or liquid bubble. However, liquid bubble seems to have certain advantages over air such as the generation of yield, larger diameter and higher maintenance of endothelial cell density and integrity. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  20. Clinical application of TICL implantation for ametropia following deep anterior lamellar keratoplasty for keratoconus

    PubMed Central

    Qin, Qin; Yang, Liping; He, Zifang; Huang, Zhenping

    2017-01-01

    Abstract Background: This study aimed to investigate the clinical application of phakic toric intraocular collamer lens (TICL) implantation in treating ametropia following deep anterior lamellar keratoplasty (DALK) for patients with keratoconus, especially the effectiveness and safety of high astigmatism and indications of TICL implantation after corneal transplantation. Methods: Using the self-controlled case series observation approach, 9 patients with ametropia (9 eyes) who underwent DALK surgery for keratoconus 1.5 years ago with stitches removed 3 months ago were kept under observation from May 2013 to April 2014 in Ophthalmic Center of Nanjing Drum Tower Hospital affiliated to Nanjing Medical University. TICL implantation was performed in all patients. The uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) were examined before surgery and 1 week, 6 months, 1 year, and 2 years after surgery. Corneal astigmatism, corneal thickness, anterior chamber depth, corneal endothelial cell density (ECD), and preoperative and postoperative intraocular pressures at different time points were measured. Intraoperative or postoperative complications of TICL implantation were observed, and the safety of the operation was evaluated. Results: The UCVA and BCVA in all operated eyes were better 6 months after surgery than before surgery. The spherical diopter and cylindrical diopter decreased to different degrees after surgery. Six months after surgery, the deviation of TICL axis in all operated eyes was less than 10 degrees, tending to be stable. No severe intraoperative or postoperative complication occurred. Conclusion: TICL implantation was an optional choice for ametropia correction after DALK surgery, especially in patients with high astigmatism. PMID:28225492

  1. Organ culture storage of pre-prepared corneal donor material for Descemet's membrane endothelial keratoplasty

    PubMed Central

    Bhogal, Maninder; Matter, Karl; Balda, Maria S; Allan, Bruce D

    2016-01-01

    Purpose To evaluate the effect of media composition and storage method on pre-prepared Descemet's membrane endothelial keratoplasty (DMEK) grafts. Methods 50 corneas were used. Endothelial wound healing and proliferation in different media were assessed using a standard injury model. DMEK grafts were stored using three methods: peeling with free scroll storage; partial peeling with storage on the stroma and fluid bubble separation with storage on the stroma. Endothelial cell (EC) phenotype and the extent of endothelial overgrowth were examined. Global cell viability was assessed for storage methods that maintained a normal cell phenotype. Results 1 mm wounds healed within 4 days. Enhanced media did not increase EC proliferation but may have increased EC migration into the wounded area. Grafts that had been trephined showed evidence of EC overgrowth, whereas preservation of a physical barrier in the bubble group prevented this. In grafts stored in enhanced media or reapposed to the stroma after trephination, endothelial migration occurred sooner and cells underwent endothelial-mesenchymal transformation. Ongoing cell loss, with new patterns of cell death, was observed after returning grafts to storage. Grafts stored as free scrolls retained more viable ECs than grafts prepared with the fluid bubble method (74.2± 3% vs 60.3±6%, p=0.04 (n=8). Conclusion Free scroll storage is superior to liquid bubble and partial peeling techniques. Free scrolls only showed overgrowth of ECs after 4 days in organ culture, indicating a viable time window for the clinical use of pre-prepared DMEK donor material using this method. Methods for tissue preparation and storage media developed for whole corneas should not be used in pre-prepared DMEK grafts without prior evaluation. PMID:27543290

  2. Histologic evaluation of human posterior lamellar discs for femtosecond laser Descemet's stripping endothelial keratoplasty.

    PubMed

    Cheng, Yanny Y Y; Kang, Shin J; Grossniklaus, Hans E; Pels, Elisabeth; Duimel, Hans J Q; Frederik, Peter M; Hendrikse, Fred; Nuijts, Rudy M M A

    2009-01-01

    To evaluate the histologic changes in corneal structure after femtosecond laser preparation of posterior lamellar discs, more specifically, the smoothness of the stromal bed and the accuracy of the predicted depth of the horizontal lamellar cut. Nineteen human donor eyes unsuitable for transplantation were used. Femtosecond laser was used to prepare a horizontal lamellar cut in donor corneas at a depth of 400 microm. Transmission electron microscopy images were used to evaluate the changes in the corneal structure and to measure the damage zone. Scanning electron microscopy images were used to determine the relative depth of the horizontal lamellar cut, and the stromal bed was examined to determine the smoothness of the surface. Transmission electron microscopy images showed a mean damage zone of 6.8 +/- 3.1 microm, which consisted of irregularly oriented collagen fibrils and electron-dense granular material. The collagen lamellae, both anteriorly and posteriorly of the damaged zone, showed a regular parallel configuration. The relative depth of the horizontal lamellar cut as percentage of the total corneal thickness in the center and periphery was 70.4% +/- 4.5% and 55.6% +/- 5.9%. Scanning electron microscopy images of the stromal bed showed a relatively smooth surface. The femtosecond laser is effective to prepare a deep horizontal lamellar cut in a standardized method. The stromal bed is smooth and without extensive adjacent tissue damage. The is thinner in the center and thicker at the edges, which may produce a mild hyperopic shift after femtosecond laser-assisted Descemet's stripping endothelial keratoplasty.

  3. Peripheral deep anterior lamellar keratoplasty using a cryopreserved donor cornea for Terrien’s marginal degeneration*

    PubMed Central

    Huang, Dan; Qiu, Wen-ya; Zhang, Bei; Wang, Bing-hong; Yao, Yu-feng

    2014-01-01

    Objective: To evaluate the clinical efficacy of peripheral deep anterior lamellar keratoplasty (DALK) using a cryopreserved donor cornea for Terrien’s marginal degeneration (TMD). Methods: Thirty-one eyes of 27 patients with TMD underwent peripheral DALK using cryopreserved donor corneas. According to the distance between the inner edge of the lesion and the limbus, a ring-shaped or D-shaped DALK was performed. All grafts were stored at −20 °C. Cryopreserved corneoscleral rims were prepared for ring-shaped grafts and cryopreserved whole eyeballs were prepared for D-shaped grafts. The general conditions, intraoperative performance, postoperative corneal reconstruction, astigmatism, best corrected visual acuity (BCVA), and various complications were analyzed. Results: Ring-shaped DALK was performed in 28 eyes and D-shaped DALK was performed in 3 eyes. Postoperative follow-up time was (28.4±24.8) months. There was evidence of inflammation before surgery in 12 eyes (38.7%) and intraoperative perforation occurred in 13 eyes (41.9%). The corneal structures of all eyes were reconstructed. Postoperative astigmatism and BCVA showed improvement (both P=0.00) except for cases that underwent D-shaped DALK. Ten eyes (32.2%) developed transient ocular hypertension and one eye (3.2%) developed secondary glaucoma. No primary disease recurrence or corneal allograft rejection was observed. Conclusions: Peripheral DALK for TMD using cryopreserved donor tissue is an effective technique that eliminates rejection and extends the use of donor eyes. Inflammatory history or intraoperative perforation has no adverse effect on graft recovery. However, D-shaped DALK did not achieve good visual outcomes. PMID:25471835

  4. Interface quality of endothelial keratoplasty buttons obtained with optimised femtosecond laser settings.

    PubMed

    Rousseau, Antoine; Bensalem, Abdelkader; Garnier, Virginie; Savoldelli, Michèle; Saragoussi, Jean-Jacques; Renard, Gilles; Bourges, Jean-Louis

    2012-01-01

    To optimise interfaces of endothelial buttons created with femtosecond (FS) lasers. Department of Ophthalmology, Hôtel-Dieu Hospital, Paris, France. Forty-two corneas were divided into five groups of various cutting patterns and a control group of 100 μm laser in situ keratomileusis flap creation. A single path full lamellar cut (500 μm) was applied to groups 1 and 2. The same full lamellar cut was applied twice to groups 3 and 4. Two successive lamellar cuts were performed in group 5 (350 and 150 μm). 60 kHz and 150 kHz were used respectively in groups 1, 3, 5, 6 and 2, 4. In each group, different laser settings were tested to obtain the best interface quality while delivering minimal energy to the stroma. The quality of stromal interfaces from created endothelial lenticules was observed using a scanning electron microscope. Stromal adherences persisted after both the single- and double-path procedure, creating central irregularities on the endothelial lenticule. Among all groups and settings tested, the double-layer pattern (group 5) with FS full lamellar cut parameters set for diameter (mm), depth (μm), energy (μJ) and spot size/step (μm) respectively on 9.0 mm, 350 μm, 2.1 μJ, 4:4 μm and 8.3 mm, 150 μm, 0.9 μJ, 4:4 μm created the smoothest interfaces with the best reproducibility. Buttons for endothelial keratoplasty can be created with FS laser with a stromal interface quality comparable with that of refractive surgery.

  5. Deep Laser-Assisted Lamellar Anterior Keratoplasty with Microkeratome-Cut Grafts

    PubMed Central

    Yokogawa, Hideaki; Tang, Maolong; Li, Yan; Liu, Liang; Chamberlain, Winston; Huang, David

    2016-01-01

    Background The goals of this laboratory study were to evaluate the interface quality in laser-assisted lamellar anterior keratoplasty (LALAK) with microkeratome-cut grafts, and to achieve good graft–host apposition. Methods Simulated LALAK surgeries were performed on six pairs of eye bank corneoscleral discs. Anterior lamellar grafts were precut with microkeratomes. Deep femtosecond (FS) laser cuts were performed on host corneas followed by excimer laser smoothing. Different parameters of FS laser cuts and excimer laser smoothing were tested. OCT was used to measure corneal pachymetry and evaluate graft-host apposition. The interface quality was quantified in a masked fashion using a 5-point scale based on scanning electron microscopy images. Results Deep FS laser cuts at 226–380 μm resulted in visible ridges on the host bed. Excimer laser smoothing with central ablation depth of 29 μm and saline as a smoothing agent did not adequately reduce ridges (score = 4.0). Deeper excimer laser ablation of 58 μm and Optisol-GS as a smoothing agent smoothed ridges to an acceptable level (score = 2.1). Same sizing of the graft and host cut diameters with an approximately 50 μm deeper host side-cut relative to the central graft thickness provided the best graft–host fit. Conclusions Deep excimer laser ablation with a viscous smoothing agent was needed to remove ridges after deep FS lamellar cuts. The host side cut should be deep enough to accommodate thicker graft peripheral thickness compared to the center. This LALAK design provides smooth lamellar interfaces, moderately thick grafts, and good graft-host fits. PMID:26890667

  6. Deep Anterior Lamellar Keratoplasty in Keratoconic Patients with versus without Vernal Keratoconjunctivitis

    PubMed Central

    Feizi, Sepehr; Javadi, Mohammad Ali; Javadi, Fatemeh; Jafarinasab, Mohammad Reza

    2015-01-01

    Purpose: To compare the clinical outcomes of deep anterior lamellar keratoplasty (DALK) for keratoconus in patients with vernal keratoconjunctivitis (VKC) versus those without VKC. Methods: In this retrospective comparative study, records of 262 eyes with keratoconus (Group 1) and 28 keratoconic eyes with VKC (Group 2) that had undergone DALK were compiled. Reviewed parameters included length of follow-up, best-corrected visual acuity (BCVA), refractive error, complications and cumulative graft survival. Results: Mean duration of follow-up was 38.6 ± 20.2 and 34.4 ± 20.9 months in groups 1 and 2, respectively (P = 0.21). Mean post-operative BCVA was 0.19 ± 0.11 and 0.20 ± 0.15 logMAR, in groups 1 and 2 (P = 0.79). BCVA≥20/40 was achieved in 91.6 and 88.5% of eyes in groups 1 and 2, respectively (P = 0.48). Epithelial problems were encountered in 31.3 and 42.9% of operated eyes, respectively (P = 0.16). Vascularization of suture tracts and stitch abscesses were encountered more frequently in the eyes with VKC (P = 0.01 and <0.001, respectively). At the 33-month follow-up examination, rejection-free graft survival rates were 56.0% in group 1 and 33.3% in group 2, with mean durations of 41.0 and 32.1 months, respectively (P = 0.15). Graft survival rates were 98.1% in group 1 and 95.0% in group 2, with mean durations of 88.6 and 88.4 months, respectively (P = 0.74). Conclusion: Clinical outcomes of DALK in keratoconic eyes with VKC were comparable to those in eyes with keratoconus alone. However, complications such as suture tract vascularization and stitch abscesses were more common when VKC coexisted, necessitating closer monitoring. PMID:26425311

  7. A Novel Tectonic Keratoplasty with Femtosecond Laser Intrastromal Lenticule for Corneal Ulcer and Perforation

    PubMed Central

    Jiang, Yang; Li, Ying; Liu, Xiao-Wei; Xu, Jing

    2016-01-01

    Background: Small incision refractive lenticule extraction (SMILE) is an effective laser procedure that treats myopia. This research was to describe a novel approach to treat corneal ulcer or perforation using the corneal lenticules obtained from SMILE and to evaluate the safety and effectiveness of tectonic keratoplasty with femtosecond laser intrastromal lenticule (TEKIL). Methods: A total of twenty patients (22 eyes) were monitored for at least 6 months and were assessed using slit lamp microscopy, optical coherence tomography, and best-corrected visual acuity (BCVA). Postoperative complications throughout the study period were recorded. Results: Corneal ulcer in 14 patients (16 eyes) and corneal perforation in six patients (6 eyes) were treated with TEKIL. The patients were ten females and ten males, with a mean age of 58.5 ± 16.3 years (range: 16–81 years). In this study, the most causes of corneal ulcer or perforation were immunologic causes (54.5%). After TEKIL procedure, global integrity was achieved in all cases. No immune rejection or perforation was detected. The mean BCVA improved from 0.17 ± 0.20 preoperatively to 0.27 ± 0.25 postoperatively at the final follow-up (t = 2.095, P = 0.052). The postoperative BCVA improved in 12 eyes (54.5%) and maintained in nine eyes (40.9%). Vision function successfully maintained in all eyes (100%). In three cases, corneal ulcers were treated by reoperation of TEKIL at 3 months after the initial surgery for the reason that the residual corneal thickness was <250 μm. Conclusions: TEKIL seems to be an effective treatment for corneal ulcer and perforation in the condition of emergency and donor shortage. PMID:27453231

  8. Dual Laser-Assisted Lamellar Anterior Keratoplasty with Tophat Graft: A Laboratory Study

    PubMed Central

    Cleary, Catherine; Song, Jonathan C.; Tang, Maolong; Li, Yan; Liu, Ying; Yiu, Samuel; Huang, David

    2011-01-01

    Objectives To develop a dual laser-assisted lamellar anterior keratoplasty (LALAK) technique, using excimer and femtosecond lasers to perform surgery on eye-bank eyes. Methods First we compared corneal stromal surfaces produced by (1) deep excimer ablation, (2) femtosecond lamellar cuts, and (3) manual dissection, and evaluated the effect of excimer laser smoothing with fluid masking on each surface. Masked observers graded scanning electron microscopy (SEM) images on a 5-point roughness scale. Then we performed a 6-mm diameter excimer laser phototherapeutic keratectomy (PTK) ablation to a residual bed thickness of 200μm, followed by laser smoothing. We used the femtosecond laser to cut donors in a modified top-hat design with a thin tapered brim, which fitted into a manually dissected circumferential pocket at the base of the recipient bed. Fourier-domain optical coherence tomography (OCT) was used to measure corneal pachymetry and evaluate graft fit. Results Deep excimer ablation with smoothing (n=4) produced a significantly (p<0.05) smoother surface (grade=3.5) than deep excimer alone (n=4, grade=3.8) or manual dissection with (n=1, grade=3.8) and without smoothing (n=1, grade=4.8). Deep femtosecond cuts (n=2) produced macroscopic concentric ridges on the stromal surface. Experimental LALAK was performed on 4 recipients prepared by deep excimer ablation and 4 donors cut with the femtosecond laser. After suturing good peripheral graft-host match was observed on FD-OCT imaging. Conclusion These preliminary studies show that the LALAK technique permits improved interface smoothness and graft edge matching. Clinical trials are needed to determine whether these improvements can translate to better vision. PMID:22378114

  9. Astigmatism Correction With Toric Intraocular Lenses in Descemet Membrane Endothelial Keratoplasty Triple Procedures.

    PubMed

    Yokogawa, Hideaki; Sanchez, P James; Mayko, Zachary M; Straiko, Michael D; Terry, Mark A

    2017-03-01

    To report the clinical efficacy of astigmatism correction with toric intraocular lenses (IOLs) in patients undergoing the Descemet membrane endothelial keratoplasty (DMEK) triple procedure and to evaluate the accuracy of the correction. Fifteen eyes of 10 patients who received cataract extraction, toric IOL placement, and DMEK surgery for Fuchs corneal dystrophy and cataracts were evaluated. The cylinder power of toric IOLs was determined by an online toric calculator with keratoscopy measurements obtained using Scheimpflug corneal imaging. Prediction errors were assessed as a difference vector between the anticipated minus postoperative residual astigmatism. At 10.1 ± 4.9 months postoperatively, 8/13 (61.5%) of eyes achieved uncorrected distance visual acuity better than 20/40. Mean best spectacle-corrected distance visual acuity (logMAR) improved from 0.21 ± 0.15 preoperatively to 0.08 ± 0.12 postoperatively (P < 0.01). The magnitude of refractive astigmatism was also significantly decreased from 2.23 ± 1.10 D (range 0.75-4.25 D) preoperatively to 0.87 ± 0.75 D (range 0.00-3.00 D) postoperatively (P < 0.01). In 1 eye with rotational misalignment by 43 degrees, we found no improvement of astigmatism. The prediction error of astigmatism at the corneal plane was 0.77 ± 0.54 D (range 0.10-1.77 D). Four eyes with preoperative "with-the-rule" corneal astigmatism had postoperative "against-the-rule" refractive astigmatism. For patients with Fuchs corneal dystrophy and cataracts, use of toric IOLs might be a valuable option in triple DMEK surgery. Additionally, care should be taken to prevent excessive IOL rotation.

  10. Corneal Astigmatism Stability in Descemet Membrane Endothelial Keratoplasty for Fuchs Corneal Dystrophy.

    PubMed

    Yokogawa, Hideaki; Sanchez, P James; Mayko, Zachary M; Straiko, Michael D; Terry, Mark A

    2016-07-01

    To calculate the magnitude and angle of the shift in corneal astigmatism associated with Descemet membrane endothelial keratoplasty (DMEK) surgery to determine the feasibility of concurrent astigmatism correction at the time of DMEK triple procedures. Retrospective study. Forty-seven eyes that previously underwent the DMEK procedure for Fuchs endothelial corneal dystrophy and that had more than 1.0 diopter (D) of front corneal astigmatism preoperatively were identified. All DMEK surgeries used a clear corneal temporal incision of 3.2 mm. Surgically induced astigmatism (SIA) was evaluated 6 months postsurgery with vector analysis using Scheimpflug image reading. We did not find a difference between pre- and postoperative magnitude of front astigmatism (P = 0.88; paired t test). The magnitude of the SIA front surface was 0.77 ± 0.63 D (range, 0.10-3.14 D). The centroid vector of the SIA front surface was 0.14 at 89.3°. A hyperopic corneal power shift was noted in both the front surface by 0.26 ± 0.74 D (range, 0.45-3.05 D) (P = 0.018; paired t test) and back surface by 0.56 ± 0.55 D (range, 0.25-2.40 D) (P < 0.01; paired t test). DMEK surgery induces minimal amounts of corneal astigmatism that is a with-the-rule shift associated with a temporal clear corneal incision. The stability of these data from preop to postop supports the plausibility of incorporating astigmatism correction with the cautious use of toric intraocular lenses for patients with Fuchs corneal dystrophy and cataract.

  11. Modified big-bubble deep anterior lamellar keratoplasty using peripheral air injection.

    PubMed

    Feizi, Sepehr; Faramarzi, Amir; Javadi, Mohammad Ali; Jafarinasab, Mohammad Reza

    2014-11-01

    To introduce a modification to big-bubble deep anterior lamellar keratoplasty (DALK) which can decrease the risk of Descemet membrane (DM) perforation during air injection. In Anwar's big-bubble technique, a 27-guage needle is inserted from the trephination site and advanced into the corneal stroma up to the centre. The technique we introduce modifies the original technique in the following fashion. After trephination to approximately 80% of corneal thickness, a 27-guage needle is inserted into the stroma peripherally from the trephination site towards the limbus. Air is injected gently into the deep stroma until a big bubble is formed. This technique was performed in 16 consecutive keratoconic eyes undergoing DALK. Additionally, peripheral air injection was carried out in 27 eye-bank corneas using a peripheral approach. In all (100%) eye-bank and 13 (81.3%) live corneas, a successful big bubble was easily achieved following peripheral air injection. In these 13 live corneas, all bubbles were formed at the central (n=10) or paracentral (n=3) cornea and extended centrifugally (type 1 bubble). In one of these corneas, an additional three bubbles were noted in the periphery between the DM and the pre-Descemet posterior stromal layer (Dua's layer, type 2) after a type 1 bubble was formed. In two live corneas in which peripheral air injection failed, a big bubble was successfully formed after air was injected inside the trephination site. Air injection peripheral to the trephination site is a reproducible modification to the standard technique which can decrease the risk of DM perforation during air injection. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. Comparison of 20% sulfur hexafluoride with air for intraocular tamponade in Descemet membrane endothelial keratoplasty (DMEK).

    PubMed

    Botsford, Benjamin; Vedana, Gustavo; Cope, Leslie; Yiu, Samuel C; Jun, Albert S

    2016-01-01

    To compare the effect of 20% sulfur hexafluoride (SF6) with that of air on graft detachment rates for intraocular tamponade in Descemet membrane endothelial keratoplasty (DMEK). Forty-two eyes of patients who underwent DMEK by a single surgeon (A.S.J.) at Wilmer Eye Institute between January 2012 and 2014 were identified; 21 received air for intraocular tamponade and the next consecutive 21 received SF6. The main outcome measure was the graft detachment rate; univariate and multivariate analyses were performed. The graft detachment rate was 67% in the air group and 19% in the SF6 group (p<0.05). No complete graft detachments occurred, and all partial detachments underwent intervention with injection of intraocular air. The percentages of eyes with 20/25 or better vision were not different between the groups (67% vs. 71%). Univariate analysis showed significantly higher detachment rates with air tamponade (OR, 8.50; p<0.005) and larger donor graft size (OR, 14.96; p<0.05). Multivariate analysis with gas but not graft size included showed that gas was an independent statistically significant predictor of outcome (OR, 6.65; p<0.05). When graft size was included as a covariate, gas was no longer a statistically significant predictor of detachment but maintained OR of 7.81 (p=0.063) similar to the results of univariate and multivariate analyses without graft size. In comparison with air, graft detachment rates for intraocular tamponade in DMEK were significantly reduced by 20% SF6.

  13. Air Bubble-Induced High Intraocular Pressure After Descemet Membrane Endothelial Keratoplasty.

    PubMed

    Röck, Daniel; Bartz-Schmidt, Karl Ulrich; Röck, Tobias; Yoeruek, Efdal

    2016-08-01

    To investigate the incidence and risk factors of pupillary block caused by an air bubble in the anterior chamber in the early postoperative period after Descemet membrane endothelial keratoplasty (DMEK). A retrospective review was conducted in 306 eyes that underwent DMEK from September 2009 through October 2014 at the Tübingen Eye Hospital. Intraocular pressure (IOP) elevation was defined as a spike above 30 mm Hg. In the first 190 eyes, an intraoperative peripheral iridectomy was performed at the 12-o'clock position and in the other 116 eyes at the 6-o'clock position. If possible, reasons for IOP elevation were identified. For all eyes, preoperative and postoperative slit-lamp examinations and IOP measurements were performed. Overall, 30 eyes (9.8%) showed a postoperative IOP elevation within the first postoperative day. The incidence of IOP elevation was 13.9% (5/36) in the triple DMEK group, and 2 of 5 phakic eyes (40%) developed an air bubble-induced IOP elevation. All eyes presented with a de novo IOP elevation, associated in 25 patients with pupillary block from air anterior to iris and in 5 patients with angle closure from air migration posterior to the iris. All of them had an iridectomy at the 12-o'clock position. A postoperative pupillary block with IOP elevation caused by the residual intraoperative air bubble may be an important complication that could be avoided by close and frequent observations, especially in the first postoperative hours and by an inferior peripheral iridectomy and an air bubble with a volume of ≤80% of the anterior chamber.

  14. Rebubbling in Descemet Membrane Endothelial Keratoplasty: Influence of Pressure and Duration of the Intracameral Air Tamponade.

    PubMed

    Pilger, Daniel; Wilkemeyer, Ina; Schroeter, Jan; Maier, Anna-Karina B; Torun, Necip

    2017-06-01

    To explore the impact of intracameral air tamponade pressure and duration on graft attachment and rebubbling rates. A prospective, interventional, nonrandomized study. setting: Department of Ophthalmology, Charité - Universitätsmedizin Berlin. One hundred seventeen patients who underwent Descemet membrane endothelial keratoplasty (DMEK). Intraocular pressure (IOP) at the end of the surgery, immediately after filling the anterior chamber with air, categorized into low (<10 mm Hg), normal (10-20 mm Hg), and high (>20 mm Hg), and the time until partial removal of the air. Rebubbling rates and endothelial cell density over a 3-month follow-up period analyzed by a multivariable Cox regression model and an analysis of covariance model. Thirty-two patients required a rebubbling (27% [95% CI 19%-35%]). Nine patients required more than 1 rebubbling (7% [95% CI 3%-12%]). Compared with normal IOP, lower (HR 8.98 [95% CI 1.07-75.41]) and higher IOP (HR 10.63 [95% CI 1.44-78.27]) increased the risk of requiring a rebubbling (P = .006). Independent of the IOP, an air tamponade duration beyond 2 hours reduced the risk of rebubbling (HR 0.36 [95% CI 0.18-0.71, P = .003]). One month after surgery, the mean endothelial cell loss was 13% (95% CI 2%-25%) and 23% (95% CI 17%-29%) in the group with air tamponade duration of below and above 2 hours, respectively (P = .126). At 3 months after surgery, it was 31% (95% CI 17%-42%) and 42% (95% CI 32%-52%) in the respective groups (P = .229). A postsurgical air tamponade of at least 2 hours with an IOP within the physiological range could help to reduce rebubbling rates. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Deep Anterior Lamellar Keratoplasty in Keratoconic Patients with versus without Vernal Keratoconjunctivitis.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad Ali; Javadi, Fatemeh; Jafarinasab, Mohammad Reza

    2015-01-01

    To compare the clinical outcomes of deep anterior lamellar keratoplasty (DALK) for keratoconus in patients with vernal keratoconjunctivitis (VKC) versus those without VKC. In this retrospective comparative study, records of 262 eyes with keratoconus (Group 1) and 28 keratoconic eyes with VKC (Group 2) that had undergone DALK were compiled. Reviewed parameters included length of follow-up, best-corrected visual acuity (BCVA), refractive error, complications and cumulative graft survival. Mean duration of follow-up was 38.6 ± 20.2 and 34.4 ± 20.9 months in groups 1 and 2, respectively (P = 0.21). Mean post-operative BCVA was 0.19 ± 0.11 and 0.20 ± 0.15 logMAR, in groups 1 and 2 (P = 0.79). BCVA≥20/40 was achieved in 91.6 and 88.5% of eyes in groups 1 and 2, respectively (P = 0.48). Epithelial problems were encountered in 31.3 and 42.9% of operated eyes, respectively (P = 0.16). Vascularization of suture tracts and stitch abscesses were encountered more frequently in the eyes with VKC (P = 0.01 and <0.001, respectively). At the 33-month follow-up examination, rejection-free graft survival rates were 56.0% in group 1 and 33.3% in group 2, with mean durations of 41.0 and 32.1 months, respectively (P = 0.15). Graft survival rates were 98.1% in group 1 and 95.0% in group 2, with mean durations of 88.6 and 88.4 months, respectively (P = 0.74). Clinical outcomes of DALK in keratoconic eyes with VKC were comparable to those in eyes with keratoconus alone. However, complications such as suture tract vascularization and stitch abscesses were more common when VKC coexisted, necessitating closer monitoring.

  16. Donor Descemet-off versus Descemet-on deep anterior lamellar keratoplasty: a confocal scan study.

    PubMed

    Feizi, Sepehr; Zare, Mohammad; Hosseini, Seyed Bagher; Kanavi, Mozhgan Rezaee; Yazdani, Shahin

    2015-01-01

    To compare confocal features of grafts following deep anterior lamellar keratoplasty (DALK) using a donor without Descemet membrane (DM) versus a full-thickness donor with intact DM and endothelium. This retrospective comparative study examined 45 eyes from patients with keratoconus who underwent DALK using the big-bubble technique. The big-bubble technique yielded a bared DM in all keratoconic eyes. Twenty-seven eyes received tissue from a donor without DM (group 1), while 18 received tissue from a full-thickness donor with an intact DM and endothelium (group 2). A group of normal eyes (n = 28, group 3) served as controls. Confocal microscopy was used to determine keratocyte density, explore the donor-recipient interface including clarity and reflectivity, evaluate endothelial cell density and morphology, as well as measure interface depth and central corneal thickness. Mean follow-up duration was 20.2 ± 8.6 months and 29.6 ± 17.0 months in groups 1 and 2, respectively (p = 0.13). Confocal scan demonstrated that the keratocyte profiles and distribution were more similar to normal corneas in group 2. Significantly more severe interface haziness was observed when donor DM and endothelium was retained (mean interface reflectivity value of 102.7 ± 22.1 versus 161.7 ± 30.0 light reflectance units in groups 1 and 2, respectively, p<0.001). Graft cellular profiles and healing response at the donor-recipient interface can be profoundly affected depending on whether donor DM and endothelium is removed or retained.

  17. The Big-Bubble Full Femtosecond Laser-Assisted Technique in Deep Anterior Lamellar Keratoplasty.

    PubMed

    Buzzonetti, Luca; Petrocelli, Gianni; Valente, Paola; Iarossi, Giancarlo; Ardia, Roberta; Petroni, Sergio; Parrilla, Rosa

    2015-12-01

    To describe the big-bubble full femtosecond laser-assisted (BBFF) technique, which could be helpful in standardizing the big-bubble technique in deep anterior lamellar keratoplasty (DALK). Ten eyes of 10 consecutive patients affected by keratoconus underwent the BBFF technique using the 150-kHz IntraLase femtosecond laser (Intra-Lase FS Laser; Abbott Medical Optics, Inc., Santa Ana, CA). A 9-mm diameter metal mask with a single fissure 0.7 mm wide oriented at the 12-o'clock position was positioned into the cone, over the laser glass. The laser performed a ring lamellar cut (internal diameter = 3 mm; external diameter = 8 mm) 100 µm above the thinnest point, with the photodisruption effectively occurring only in the corneal stroma corresponding to the fissure to create a deep stromal channel; subsequently, an anterior side cut created an arcuate incision, from the corneal surface to the deep stromal channel on the mask's opening site. The mask was removed and the laser performed a full lamellar cut 200 µm above the thinnest point to create a lamella. After the removal of the lamella, the air needle was inserted into the stromal channel and air was injected to achieve a big bubble. The big bubble was achieved in 9 eyes (all type 1 bubbles) and all procedures were completed as DALK. Preliminary results suggest that the BBFF technique could help in standardizing the big-bubble technique in DALK, reducing the "learning curve" for surgeons who approach this technique and the risks of intraoperative complications. Copyright 2015, SLACK Incorporated.

  18. Image-guided modified deep anterior lamellar keratoplasty (DALK) corneal transplant using intraoperative optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Tao, Yuankai K.; LaBarbera, Michael; Ehlers, Justis P.; Srivastava, Sunil K.; Dupps, William J.

    2015-03-01

    Deep anterior lamellar keratoplasty (DALK) is an alternative to full-thickness corneal transplant and has advantages including the absence of allograft rejection; shortened duration of topical corticosteroid treatment and reduced associated risk of glaucoma, cataract, or infection; and enables use of grafts with poor endothelial quality. DALK begins by performing a trephination of approximately 80% stromal thickness, as measured by pachymetry. After removal of the anterior stoma, a needle is inserted into the residual stroma to inject air or viscoelastic to dissect Descemet's membrane. These procedures are inherently difficult and intraoperative rates of Descemet's membrane perforation between 4-39% have been reported. Optical coherence tomography (OCT) provides high-resolution images of tissue microstructures in the cornea, including Descemet's membrane, and allows quantitation of corneal layer thicknesses. Here, we use crosssectional intraoperative OCT (iOCT) measurements of corneal thickness during surgery and a novel micrometeradjustable biopsy punch to precision-cut the stroma down to Descemet's membrane. Our prototype cutting tool allows us to establish a dissection plane at the corneal endothelium interface, mitigates variability in cut-depths as a result of tremor, reduces procedure complexity, and reduces complication rates. iOCT-guided modified DALK procedures were performed on 47 cadaveric porcine eyes by non-experts and achieved a perforation rate of ~5% with a mean corneal dissection time <18 minutes. The procedure was also successful performed on a human donor eye without perforation. Our data shows the potential for iOCT-guided precision anterior segment surgery without variability as a result of tremor and improvements to standard clinical care.

  19. Foliar penetration enhanced by biosurfactant rhamnolipid.

    PubMed

    Liu, Haojing; Shao, Bing; Long, Xuwei; Yao, Yang; Meng, Qin

    2016-09-01

    With recent environmental and health concerns, biosurfactants have obtained increasing interest in replacing conventional surfactants for diverse applications. In agriculture, the use of surfactant in stimulating foliar uptake is mainly for wetting leaf surface, resisting deposition/evaporation, enhancing penetration across cuticular membrane (CM) and translocation. This paper aimed to address the improved foliar uptake by rhamnolipid (RL) in comparison with the currently used alkyl polyglucoside (APG). As found, compared with APG at 900mg/L (1×critical micellar concentration, CMC), RL at a much lower concentration of 50mg/L (1×CMC) showed much better wettability and surface activity, indicative of its high effectiveness as surfactants. Its performance on resistance to deposition and evaporation was at least as same as APG. Moreover, RL could significantly improve the penetration of herbicide glyphosate and other two small water-soluble molecules (phenol red and Fe(2+)) across CM at an equivalent efficiency as APG at 1×CMC. Finally, the greatly enhanced herbicidal actitivity of glyphosate on greenhouse plants confirmed that RL and APG could both enhance the foliar uptake including translocation. Overall, RL should be more applicable than APG in agriculture due to its more promising properties on health/environmental friendliness. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Objective, comparative assessment of the penetration depth of temporal-focusing microscopy for imaging various organs

    PubMed Central

    Rowlands, Christopher J.; Bruns, Oliver T.; Bawendi, Moungi G.; So, Peter T. C.

    2015-01-01

    Abstract. Temporal focusing is a technique for performing axially resolved widefield multiphoton microscopy with a large field of view. Despite significant advantages over conventional point-scanning multiphoton microscopy in terms of imaging speed, the need to collect the whole image simultaneously means that it is expected to achieve a lower penetration depth in common biological samples compared to point-scanning. We assess the penetration depth using a rigorous objective criterion based on the modulation transfer function, comparing it to point-scanning multiphoton microscopy. Measurements are performed in a variety of mouse organs in order to provide practical guidance as to the achievable penetration depth for both imaging techniques. It is found that two-photon scanning microscopy has approximately twice the penetration depth of temporal-focusing microscopy, and that penetration depth is organ-specific; the heart has the lowest penetration depth, followed by the liver, lungs, and kidneys, then the spleen, and finally white adipose tissue. PMID:25844509

  1. Objective, comparative assessment of the penetration depth of temporal-focusing microscopy for imaging various organs

    NASA Astrophysics Data System (ADS)

    Rowlands, Christopher J.; Bruns, Oliver T.; Bawendi, Moungi G.; So, Peter T. C.

    2015-06-01

    Temporal focusing is a technique for performing axially resolved widefield multiphoton microscopy with a large field of view. Despite significant advantages over conventional point-scanning multiphoton microscopy in terms of imaging speed, the need to collect the whole image simultaneously means that it is expected to achieve a lower penetration depth in common biological samples compared to point-scanning. We assess the penetration depth using a rigorous objective criterion based on the modulation transfer function, comparing it to point-scanning multiphoton microscopy. Measurements are performed in a variety of mouse organs in order to provide practical guidance as to the achievable penetration depth for both imaging techniques. It is found that two-photon scanning microscopy has approximately twice the penetration depth of temporal-focusing microscopy, and that penetration depth is organ-specific; the heart has the lowest penetration depth, followed by the liver, lungs, and kidneys, then the spleen, and finally white adipose tissue.

  2. Double-Plate Penetration Equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    2000-01-01

    This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

  3. Long-term follow-up after lamellar keratoplasty in a patient with bilateral idiopathic corneal keloid.

    PubMed

    Fukuda, Ken; Chikama, Tai-ichiro; Takahashi, Mutsuo; Nishida, Teruo

    2011-12-01

    To report a case of bilateral idiopathic corneal keloid. Retrospective review of clinical features, histopathological findings, clinical management, and outcome. A 2-year-old boy with bilateral corneal keloid was treated with lamellar keratoplasty and tranilast eye drops. Peripheral localized white corneal nodules had been present bilaterally since the age of approximately 6 months in the absence of any history of trauma, inflammatory disease, or relevant family history. Pathological examination of the excised corneal buttons revealed myofibroblast proliferation (positive staining for α-smooth muscle actins), a haphazard arrangement of collagen bundles, and the absence of inflammatory cells. On the basis of these findings, a diagnosis of corneal keloid was assigned. The size of the corneal lesion in the right eye decreased in response to therapy with tranilast eye drops. Lamellar keratoplasty resulted in improved bilateral visual acuity, which was maintained at the 12-year follow-up. This report describes a very rare case of bilateral corneal keloid in the absence of trauma or inflammation that was diagnosed by histological and immunohistochemical examination and electron microscopy. Good visual acuity was maintained over an extended period of postsurgery follow-up. Tranilast may represent a novel adjuvant therapy for corneal keloid.

  4. Corneal Melting Two Weeks after Pterygium Excision with Topical Mitomycin C: Successfully Treated with Lamellar Keratoplasty and Amnion Membrane Transplantation

    PubMed Central

    Menghini, Moreno; Watson, Stephanie L.; Bosch, Martina M.

    2012-01-01

    Purpose To report the management of a case of corneal melting two weeks after pterygium excision with intraoperative topical mitomycin C (MMC). Methods Case report. Results A 57-year-old male was referred to our Department for therapy of rapidly progressive corneal melting two weeks after primary pterygium surgery with MMC (0.2 mg/ml) in September 2009. Initial treatment consisted of topical and systemic immunosuppression along with topical antibiotics. Eight days after presentation, the patient underwent successful lamellar keratoplasty and amnion membrane transplantation. Subconjunctival injection of triamcinolone (40 mg/ml) and topical bevacizumab were used to manage the increased fibrovascular activity around the site of the former pterygium. Conclusion Topical use of MMC during pterygium surgery may be related to serious postoperative complications such as progressive inflammatory corneal melting. The etiology may be multifactorial, which is related to MMC-induced inflammation and/or induced apoptosis. A therapeutic option is the described combination of systemic and local anti-inflammatory treatment along with lamellar keratoplasty and amniotic membrane transplantation. Adjunctive therapy may be needed if recurrence occurs. PMID:22615697

  5. Two cases of ultrathin Descemet stripping automated endothelial keratoplasty utilizing a graft that had undergone radial keratotomy

    PubMed Central

    Nahum, Yoav; Ponzin, Diego; Busin, Massimo

    2016-01-01

    This is a report of two cases in which tissue that had undergone radial keratotomy (RK) was utilized for double-pass ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK). Postoperative slit-lamp examination, visual acuity, anterior segment optical coherence tomography, and specular microscopy were available 30 months after surgery. Both corneas from a donor, who had undergone RK several years before his demise, and were otherwise suitable for endothelial keratoplasty were prepared for UT-DSAEK using double-pass dissection using first a 300 mm microkeratome head and then a 130μm microkeratome head (ALTK system, Moria, Antony, France). After the second cut, the tissue was punched to 9.0 mm and transplanted in two eyes with endothelial decompensation according to standard technique. As early as 3 months after surgery, both patients had 20/25 best-corrected visual acuity, which remained stable for the following 27 months. Postoperative endothelial cell loss was 34% and 57% at 2.5 years. In conclusion, post-RK donor tissue can be used for UT-DSAEK. PMID:27050357

  6. ‘Expanding bubble' modification of ‘big-bubble' technique for performing maximum-depth anterior lamellar keratoplasty

    PubMed Central

    Daneshgar, F; Fallahtafti, M

    2011-01-01

    Purpose To describe a new technique for performing maximum-depth anterior lamellar keratoplasty. Methods This was a case series study using a novel method. We introduce and describe a new sign (sunny-side up sign) that reveals the presence and extent of the air bubble at the Descemet membrane (DM)–stroma interface. We also report a novel technique to expand the bubble by injecting viscoelastic material into the bubble cavity and to excise the stromal tissues within the trephination area almost completely. The follow-up period ranged from 12 to 16 months. In all patients we recorded the best spectacle-corrected visual acuity, keratometry, and endothelial cell count preoperatively and postoperatively and the air bubble diameter using the sunny-side up sign. Results In eight of nine patients, a big bubble formed. The size of the air bubble ranged from 2 to 7 mm. All the bubbles were expanded to 8 mm and the bare DM throughout the trephination area was obtained in all cases. The postoperative mean keratometric readings were reduced compared with the preoperative mean keratometric readings. The BSCVA was increased postoperatively compared with the preoperative acuity. The difference between the preoperative and postoperative endothelial cell counts was not statistically significant. Conclusions The early outcomes in our series using the expanding bubble technique suggest that it is safe and easy in performing maximum-depth anterior lamellar keratoplasty. PMID:21475313

  7. Lunar regolith penetrators and cutters

    NASA Technical Reports Server (NTRS)

    Barnes, Frank; Sture, Stein

    1991-01-01

    An apparatus was designed and built for conducting simulation experiments on cutting tool penetration in the centrifuge. This equipment is mounted on the laminar container which is used for the regolith densification study, so that the end product of the latter, i.e., a regolith bed with the proper density profile, can be used directly for the penetration tests. In this apparatus, an etching tool is suspended through a pulley system by the action of a double acting air cylinder. By adjusting the air pressure acting on each side of the cylinder, the net downward force acting on the tool can be controlled. The penetration of the tool is measured by an LVDT. This apparatus was proof-tested in the centrifuge and is ready for use in conjunction with the regolith densification experiments.

  8. Detection and sizing of defects in control rod drive mechanism penetrations using eddy current and ultrasonics

    SciTech Connect

    Light, G.M.; Fisher, J.L.; Tennis, R.F.; Stolte, J.S.; Hendrix, G.J.

    1996-08-01

    Over the last two years, concern has been generated about the capabilities of performing nondestructive evaluation (NDE) of the closure-head penetrations in nuclear-reactor pressure vessels. These penetrations are primarily for instrumentation and control rod drive mechanisms (CRDMs) and are usually thick-walled Inconel tubes, which are shrink-fitted into the steel closure head. The penetrations are then welded between the outside surface of the penetration and the inside surface of the closure head. Stress corrosion cracks initiating at the inner surface of the penetration have been reported at several plants. Through-wall cracks in the CRDM penetration or CRDM weld could lead to loss of coolant in the reactor vessel. The CRDM penetration presents a complex inspection geometry for conventional NDE techniques. A thermal sleeve, through which pass the mechanical linkages for operating the control rods, is inserted into the penetration in such a way that only a small annulus (nominally 3 mm) exists between the thermal sleeve and inside surface of the penetration. Ultrasonic (UT) and eddy current testing (ET) techniques that could be used to provide defect detection and sizing capability were investigated. This paper describes the ET and UT techniques, the probes developed, and the results obtained using these probes and techniques on CRDM penetration mock-ups.

  9. [Penetrating transorbital intracranial foreign body].

    PubMed

    Civelek, Erdinç; Bilgiç, Salih; Kabataş, Serdar; Hepgül, Kemal Tanju

    2006-07-01

    We report a seven year-old boy who suffered left orbital penetration of an industrial sewing machine needle. The needle passing through the left orbit and sphenoid bone at the posterior was extending into the layers of the dura of the left temporal lobe. In this patient, we preferred surgical approach and there was no complication after surgery. Penetrating intraorbital foreign materials with intracranial extension may lead to complications such as intracerebral hematoma, brain abscess, CSF fistula, proptosis of the eye, diplopia, orbital cellulitis and periorbital abscess. They have to be removed by surgical approach to prevent potential complications.

  10. Fluconazole Penetration into the Pancreas

    PubMed Central

    Shrikhande, Shailesh; Friess, Helmut; Issenegger, Claudia; Martignoni, Marcus E.; Yong, Huang; Gloor, Beat; Yeates, Rodney; Kleeff, Jörg; Büchler, Markus W.

    2000-01-01

    Because of antibiotic prophylaxis for necrotizing pancreatitis, the frequency of fungal superinfection in patients with pancreatic necrosis is increasing. In this study we analyzed the penetration of fluconazole into the human pancreas and in experimental acute pancreatitis. In human pancreatic tissues, the mean fluconazole concentration was 8.19 ± 3.38 μg/g (96% of the corresponding concentration in serum). In experimental edematous and necrotizing pancreatitis, 88 and 91% of the serum fluconazole concentration was found in the pancreas. These data show that fluconazole penetration into the pancreas is sufficient to prevent and/or treat fungal contamination in patients with pancreatic necrosis. PMID:10952621

  11. Mars surface penetrator: System description

    NASA Technical Reports Server (NTRS)

    Manning, L. A. (Editor)

    1977-01-01

    A point design of a penetrator system for a Mars mission is described. A strawman payload which is to conduct measurements of geophysical and meteorological parameters is included in the design. The subsystems used in the point design are delineated in terms of power, mass, volume, data, and functional modes. The prospects for survival of the rigors of emplacement are described. Data handling and communications plans are presented to allow consideration of the requirements placed by the penetrator on the orbiter and ground operations. The point design is technically feasible and the payload selection scientifically desirable.

  12. Molecular dynamics simulations of ballistic He penetration into W fuzz

    NASA Astrophysics Data System (ADS)

    Klaver, T. P. C.; Nordlund, K.; Morgan, T. W.; Westerhof, E.; Thijsse, B. J.; van de Sanden, M. C. M.

    2016-12-01

    Results are presented of large-scale Molecular Dynamics simulations of low-energy He bombardment of W nanorods, or so-called ‘fuzz’ structures. The goal of these simulations is to see if ballistic He penetration through W fuzz offers a more realistic scenario for how He moves through fuzz layers than He diffusion through fuzz nanorods. Instead of trying to grow a fuzz layer starting from a flat piece of bulk W, a new approach of creating a fully formed fuzz structure 0.43 µm thick out of ellipsoidal pieces of W is employed. Lack of detailed experimental knowledge of the 3D structure of fuzz is dealt with by simulating He bombardment on five different structures of 15 vol% W and determining the variation in He penetration for each case. The results show that by far the most important factor determining He penetration is the amount of open channels through which He ions can travel unimpeded. For a more or less even W density distribution He penetration into fuzz falls off exponentially with distance and can thus be described by a ‘half depth’. In a 15 vol% fuzz structure, the half depth can reach 0.18 µm. In the far sparser fuzz structures that were recently reported, the half depth might be 1 µm or more. This means that ballistic He penetration offers a more likely scenario than He diffusion through nanorods for how He moves through fuzz and may provide an adequate explanation for how He penetrates through the thickest fuzz layers reported so far. Furthermore, the exponential decrease in penetration with depth would follow a logarithmic dependence on fluence which is compatible with experiments. A comparison of these results and molecular dynamics calculations carried out in the recoil interaction approximation shows that results for W fuzz are qualitatively very different from conventional stopping power calculations on W with a similarly low but homogeneous density distribution.

  13. FAA Fluorescent Penetrant Laboratory Inspections

    SciTech Connect

    WINDES,CONNOR L.; MOORE,DAVID G.

    2000-08-02

    The Federal Aviation Administration Airworthiness Assurance NDI Validation Center currently assesses the capability of various non-destructive inspection (NDI) methods used for analyzing aircraft components. The focus of one such exercise is to evaluate the sensitivity of fluorescent liquid penetrant inspection. A baseline procedure using the water-washable fluorescent penetrant method defines a foundation for comparing the brightness of low cycle fatigue cracks in titanium test panels. The analysis of deviations in the baseline procedure will determine an acceptable range of operation for the steps in the inspection process. The data also gives insight into the depth of each crack and which step(s) of the inspection process most affect penetrant sensitivities. A set of six low cycle fatigue cracks produced in 6.35-mm thick Ti-6Al-4V specimens was used to conduct the experiments to produce sensitivity data. The results will document the consistency of the crack readings and compare previous experiments to find the best parameters for water-washable penetrant.

  14. Penetrating trauma to the extremity.

    PubMed

    Manthey, David E; Nicks, Bret A

    2008-02-01

    Penetrating trauma to the extremities is a complex disease that foremost requires the evaluation for vascular injury. This monograph will address an algorithm to assess for associated vascular injury that includes current evaluation techniques. Approaches to wound management and use of antibiotics in the ED are also addressed.

  15. Localizing Ground-Penetrating Radar

    DTIC Science & Technology

    2014-11-01

    determine the vehicles location when adverse conditions, such as heavy rain or fog , snow-covered roads, or lost GPS signals, hamper the...penetrate rain, fog , dust, and snow. LGPR Methodology For subsurface sensing, GPR is one of the most versatile and prolific sensing modal- ities today

  16. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  17. A penetrating orbitocranial stab wound.

    PubMed Central

    MacEwen, C J; Fullarton, G

    1986-01-01

    An unusual case of intracranial penetration of a bread knife through the orbit is described. Despite the proximity of the blade to the internal carotids, the optic nerves and chiasm, and the pituitary the patient survived with only a minimal field defect affecting the eye opposite to the entry site; otherwise no neurological or endocrine deficit was evident. Images PMID:3947613

  18. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  19. Descemet's Membrane Endothelial Keratoplasty: Risk of Immunologic Rejection Episodes after Discontinuing Topical Corticosteroids.

    PubMed

    Price, Marianne O; Scanameo, Amanda; Feng, Matthew T; Price, Francis W

    2016-06-01

    To assess the risk of immunologic rejection episodes if topical corticosteroids are discontinued 1 year after Descemet's membrane endothelial keratoplasty (DMEK) compared with continued once-per-day use. Prospective, longitudinal, parallel-group study. A total of 400 eyes of 259 DMEK recipients, aged 23 to 90 years. Patients were enrolled 1 year after DMEK and allowed to choose whether to stop or continue once-daily topical corticosteroids to maximize compliance. Fellow eyes were eligible for enrollment because the donor grafts were independent. Participants were examined at 1, 3, 6, and 12 months during the second year after DMEK. Results were assessed using Kaplan-Meier survival analysis. Incidence of immunologic rejection episodes. Steroids were discontinued in 277 eyes (no steroid group) and continued once per day in 123 eyes (steroid group). The subject demographics were well balanced across groups; 99% of the subjects were white, and 95% of the grafts were performed to treat Fuchs' dystrophy. The cumulative incidence of rejection episodes was significantly greater in the no steroid group (6% vs. 0% in the steroid group; P = 0.013). Thirteen of 14 rejection episodes (all in the no steroid group) resolved with resumption of topical corticosteroids. Overall, 1 of 277 grafts (0.4%) failed in the no steroid group, and none failed in the steroid group during the second year after DMEK (P = 0.49). The endothelial cell loss between 1 and 2 years was comparable in the no steroid and steroid groups (6.4%±12% vs. 5.6%±14%, respectively; P = 0.67). Continued once-per-day use of a topical corticosteroid, even a weak one, was protective against rejection episodes during the second year after DMEK, whereas 6% experienced a rejection episode when steroids were discontinued. Among the 364 eyes that completed 12 months' follow-up, only 1 graft (0.27%) failed. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  20. Cost Minimization Analysis of Precut Cornea Grafts in Descemet Stripping Automated Endothelial Keratoplasty.

    PubMed

    Yong, Kai-Ling; Nguyen, Hai V; Cajucom-Uy, Howard Y; Foo, Valencia; Tan, Donald; Finkelstein, Eric A; Mehta, Jodhbir S

    2016-02-01

    Descemet stripping automated endothelial keratoplasty (DSAEK) is the most common corneal transplant procedure. A key step in the procedure is preparing the donor cornea for transplantation. This can be accomplished via 1 of 3 alternatives: surgeon cuts the cornea on the day of surgery, the cornea is precut ahead of time in an offsite facility by a trained technician, or a precut cornea is purchased from an eye bank. Currently, there is little evidence on the costs and effectiveness of these 3 strategies to allow healthcare providers decide upon the preferred method to prepare grafts.The aim of this study was to compare the costs and relative effectiveness of each strategy.The Singapore National Eye Centre and Singapore Eye Bank performed both precut cornea and surgeon-cut cornea transplant services between 2009 and 2013.This study included 110 subjects who received precut cornea and 140 who received surgeon-cut cornea. Clinical outcomes and surgical duration were compared across the strategies using the propensity score matching. The cost of each strategy was estimated using the microcosting and consisted of facility costs and procedural costs including surgical duration. One-way sensitivity analysis and threshold analysis were performed.The cost for DSAEK was highest for the surgeon-cut approach ($13,965 per procedure), followed by purchasing precut corneas ($12,659) and then setting up precutting ($12,421). The higher procedural cost of the surgeon-cut approach was largely due to the longer duration of the procedure (surgeon-cut = 72.54 minutes, precut = 59.45 minutes, P < 0.001) and the higher surgeon fees. There was no evidence of differences in clinical outcomes between grafts that were precut or surgeon-cut. Threshold analysis demonstrated that if the number of cases was below 31 a year, the strategy that yielded the lowest cost was purchasing precut cornea from eye bank. If there were more than 290 cases annually, the cheapest option would be

  1. Large-diameter deep anterior lamellar keratoplasty for keratoconus: visual and refractive outcomes.

    PubMed

    Huang, Ting; Hu, Yunwei; Gui, Mengru; Zhang, Hong; Wang, Yun; Hou, Chao

    2015-09-01

    To investigate the difference in clinical outcomes between large-diameter deep anterior lamellar keratoplasty (L-DALK) and standard DALK (S-DALK) for the treatment of keratoconus. 132 patients (132 eyes) from the Zhongshan Ophthalmic Center with a clinical diagnosis of keratoconus were enrolled. The participants were featured by the intolerance to rigid gas-permeable contact lenses or unsuccessful fitting of contact lenses. Using stratified blocked randomisation, eligible eyes were allocated into the L-DALK group or the S-DALK group (66 eyes, respectively). Postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refractive sphere, manifest cylinder and spherical equivalent refractive error were tested at 6, 12, 18 and 24 months after surgery. After surgery, the L-DALK group had better UCVA and BSCVA than the S-DALK group (p=0.000 and 0.021, respectively). At 24 months, mean BSCVA was 0.17±0.10 logarithm of the minimum angle of resolution (logMAR) (Snellen equivalent, 20/25) in the L-DALK group vs 0.22±0.10 logMAR (Snellen equivalent, 20/32) in the S-DALK group. Differences were observed between the L-DALK group and the S-DALK group in terms of refractive sphere (p=0.015), manifest cylinder (p=0.014) and spherical equivalent refractive error (p=0.034) at any time interval postoperatively. At 24 months, the mean spherical equivalent refractive error was -3.5±3.2 D and -5.2±2.6 D in the L-DALK and S-DALK groups, respectively. L-DALK can reduce the degree of postoperative myopia and manifest astigmatism and improve visual acuity outcomes in keratoconus compared with S-DALK. Chinese Clinical Trial Registry (TRC-13003122). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  2. Aachen keratoprosthesis as temporary implant for combined vitreoretinal surgery and keratoplasty: report on 10 clinical applications.

    PubMed

    Langefeld, S; Kompa, S; Redbrake, C; Brenman, K; Kirchhof, B; Schrage, N F

    2000-09-01

    A new keratoprosthesis was used during pars plana vitrectomy in order to test the optical quality, watertightness, short-term biocompatibility and handling of the new device. The implantability was also tested, given that this keratoprosthesis might in future be left in place for several months. This Aachen keratoprosthesis (Aachen-KPro) is developed to be used as permanent implant to restore vision in corneal blind patients. The Aachen-KPro was used during pars plana vitrectomy in 10 patients with opaque corneas. In four cases, trauma precipitated the ocular disease. Eye burn was the cause of corneal and retinal disorders in another four cases. One patient had a history of congenital glaucoma with myopia, and one of uveitis with corneal dystrophy. After trephination of 6.5 mm in diameter, the Aachen-KPro, composed of soft silicone rubber, was temporarily placed in the trephination hole. After completion of the vitrectomy, the Aachen-KPro was replaced by a 7 mm corneal graft. Intraoperative use of the Aachen-KPro allowed uncomplicated intraoperative handling, smooth adaptation to the corneal rim in the trephination hole, and an undistorted view of the central and peripheral retina. Leakage, even during scleral depression, could be avoided by individual suturing of the scleral rim. After a follow-up period of 1-10 months, the retina was still attached in all cases. The corneal graft was clear after surgery in four eyes, and edema was found in three cases. Amnion or conjunctiva was placed over three patients' transplants. We report the first temporary implantations of a new keratoprosthesis in 10 patients. Its flexibility and good optical qualities allowed control of intraoperative procedures. The outcome and prognosis of the vitreoretinal surgery and keratoplasty were related to the primary diagnosis. The Aachen-KPro has shown advantages, especially in eyes where the anterior eye segment is severely damaged by eye burn or previous surgical interventions. In the