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Sample records for posterior scleral mechanics

  1. Peripapillary and posterior scleral mechanics--part II: experimental and inverse finite element characterization.

    PubMed

    Girard, Michaël J A; Downs, J Crawford; Bottlang, Michael; Burgoyne, Claude F; Suh, J-K Francis

    2009-05-01

    The posterior sclera likely plays an important role in the development of glaucoma, and accurate characterization of its mechanical properties is needed to understand its impact on the more delicate optic nerve head--the primary site of damage in the disease. The posterior scleral shells from both eyes of one rhesus monkey were individually mounted on a custom-built pressurization apparatus. Intraocular pressure was incrementally increased from 5 mm Hg to 45 mm Hg, and the 3D displacements were measured using electronic speckle pattern interferometry. Finite element meshes of each posterior scleral shell were reconstructed from data generated by a 3D digitizer arm (shape) and a 20 MHz ultrasound transducer (thickness). An anisotropic hyperelastic constitutive model described in a companion paper (Girard, Downs, Burgoyne, and Suh, 2009, "Peripapillary and Posterior Scleral Mechanics--Part I: Development of an Anisotropic Hyperelastic Constitutive Model," ASME J. Biomech. Eng., 131, p. 051011), which includes stretch-induced stiffening and multidirectional alignment of the collagen fibers, was applied to each reconstructed mesh. Surface node displacements of each model were fitted to the experimental displacements using an inverse finite element method, which estimated a unique set of 13 model parameters. The predictions of the proposed constitutive model matched the 3D experimental displacements well. In both eyes, the tangent modulus increased dramatically with IOP, which indicates that the sclera is mechanically nonlinear. The sclera adjacent to the optic nerve head, known as the peripapillary sclera, was thickest and exhibited the lowest tangent modulus, which might have contributed to the uniform distribution of the structural stiffness for each entire scleral shell. Posterior scleral deformation following acute IOP elevations appears to be nonlinear and governed by the underlying scleral collagen microstructure as predicted by finite element modeling. The

  2. Peripapillary and posterior scleral mechanics--part I: development of an anisotropic hyperelastic constitutive model.

    PubMed

    Girard, Michaël J A; Downs, J Crawford; Burgoyne, Claude F; Suh, J-K Francis

    2009-05-01

    The sclera is the white outer shell and principal load-bearing tissue of the eye as it sustains the intraocular pressure. We have hypothesized that the mechanical properties of the posterior sclera play a significant role in and are altered by the development of glaucoma-an ocular disease manifested by structural damage to the optic nerve head. An anisotropic hyperelastic constitutive model is presented to simulate the mechanical behavior of the posterior sclera under acute elevations of intraocular pressure. The constitutive model is derived from fiber-reinforced composite theory, and incorporates stretch-induced stiffening of the reinforcing collagen fibers. Collagen fiber alignment was assumed to be multidirectional at local material points, confined within the plane tangent to the scleral surface, and described by the semicircular von Mises distribution. The introduction of a model parameter, namely, the fiber concentration factor, was used to control collagen fiber alignment along a preferred fiber orientation. To investigate the effects of scleral collagen fiber alignment on the overall behaviors of the posterior sclera and optic nerve head, finite element simulations of an idealized eye were performed. The four output quantities analyzed were the scleral canal expansion, the scleral canal twist, the posterior scleral canal deformation, and the posterior laminar deformation. A circumferential fiber organization in the sclera restrained scleral canal expansion but created posterior laminar deformation, whereas the opposite was observed with a meridional fiber organization. Additionally, the fiber concentration factor acted as an amplifying parameter on the considered outputs. The present model simulation suggests that the posterior sclera has a large impact on the overall behavior of the optic nerve head. It is therefore primordial to provide accurate mechanical properties for this tissue. In a companion paper (Girard, Downs, Bottlang, Burgoyne, and Suh, 2009

  3. Ghost cell glaucoma following sutureless scleral-fixated posterior chamber intraocular lens placement.

    PubMed

    Thompson, Jordan M; Chang, Jonathan S; Bermudez-Magner, J Antonio; Dubovy, Sander R

    2015-01-01

    Secondary intraocular lens (IOL) placement in the absence of a capsular bag may result in several complications. The authors report the clinicopathologic features of a case of ghost cell glaucoma after the placement of a sutureless posterior chamber IOL. A 47-year-old male presented with a dislocated IOL and underwent lens exchange using a sutureless scleral-fixation technique. Over the following year, the patient developed recurrent vitreous hemorrhages and elevated intraocular pressure despite medical therapy, and an aqueous specimen disclosed ghost cells. Although uncommon, mechanical contact between the iris and a secondary IOL may produce persistent vitreous hemorrhage and elevated intraocular pressures with the formation of ghost cells.

  4. Posterior scleral reinforcement combined with vitrectomy for myopic foveoschisis

    PubMed Central

    Li, Xiu-Juan; Yang, Xiao-Peng; Li, Qiu-Ming; Wang, Yu-Ying; Wang, Jing; Lyu, Xiao-Bei; Jia, Heng

    2016-01-01

    AIM To investigate the effects of posterior scleral reinforcement (PSR) combined with vitrectomy for myopic foveoschisis. METHODS Thirty-nine highly myopic eyes of 39 patients with myopic foveoschisis underwent PSR combined with vitrectomy. Best corrected visual acuity (BCVA), refraction error, and the foveal thickness by optical coherence tomography (OCT) were recorded before and after the surgery, and complications were noted. RESULTS The follow-up period was 12mo, and the main focus was on the results of the 12-month follow-up visit. The mean preoperative BCVA was 0.96±0.43 logMAR. At the final follow-up visit, the mean BCVA was 0.46±0.28 logMAR, which significantly improved compared with the preoperative one (P=0.003). The BCVA improved in 33 eyes (84.62%), and unchanged in 6 eyes (15.38%). At the end of follow-up, the mean refractive error was -15.13±2.55 D, and the improvement was significantly compared with the preoperative one (-17.53±4.51 D) (P=0.002). Twelve months after surgery, OCT showed complete resolution of the myopic foveoschisis and a reat-tachment of the fovea in 37 eyes (94.87%) and partial resolution in the remained two eyes (5.13%). The foveal thickness was obviously reduced at 12-month follow-up visit (196.45±36.35 µm) compared with the preoperative one (389.32±75.56 µm) (P=0.002). There were no serious complications during the 12mo follow-up period. CONCLUSION PSR combined with vitrectomy is a safe and effective procedure for myopic foveoschisis with both visual and anatomic improvement. PMID:26949646

  5. Posterior scleral reinforcement for the treatment of pathological myopia

    PubMed Central

    Li, Xiu-Juan; Yang, Xiao-Peng; Li, Qiu-Ming; Wang, Yu-Ying; Wang, Yuan; Lyu, Xiao-Bei; Jia, Heng

    2016-01-01

    AIM To investigate the effects of posterior scleral reinforcement (PSR) in the treatment of pathological myopia. METHODS The study included 52 eyes in 43 patients with pathological myopia who underwent PSR (PSR group), and 52 eyes in 36 age- and myopia-matched patients who did not undergo such treatment as control group. Axial length, refraction error, best corrected visual acuity (BCVA), and macular scans by optical coherence tomography (OCT) were recorded at baseline, 6mo, 1, 3 and 5y after the surgery, and the complications were noted. RESULTS There were no statistical differences in axial length, refractive error, or BCVA between the PSR group and the control group at baseline. At the end of the follow-up, the mean axial length was 29.79±1.26 mm in the PSR group, which was significantly shorter than that in the control group (30.78±1.30 mm) (P<0.01), and the mean refractive error was -16.86±2.53 D in the PSR group, which was significantly lower than that in the control group (-19.18±2.12 D) (P<0.01). A statistically significant difference in BCVA was found between the PSR group (0.51±0.25 logMAR) and the control group (0.62±0.26 logMAR) at the postoperative 5-year follow-up (P<0.01). There were no serious complications during the 5-year follow-up period. CONCLUSION PSR can prevent axial elongation and myopia progression in eyes with pathological myopia. PMID:27162733

  6. Changes in posterior scleral collagen microstructure in canine eyes with an ADAMTS10 mutation

    PubMed Central

    Palko, Joel R.; Sorensen, Thomas; Mohammadvali, Ashkan; Elsheikh, Ahmed; Komáromy, András M.; Pan, Xueliang; Liu, Jun

    2016-01-01

    Purpose We aimed to characterize alterations in the posterior scleral collagen microstructure before detectable disease onset in a canine model of open-angle glaucoma caused by an ADAMTS10 mutation. Methods Collagen orientation, anisotropy degree (proportion of preferentially aligned collagen), and relative density were measured at 0.4 mm spatial resolution using synchrotron wide-angle X-ray scattering. For statistical evaluation of structure parameters, regional averages of the peripapillary and mid-posterior sclera were compared between ADAMTS10 mutant (affected) dogs (n = 3) and age-matched (carrier) controls (n = 3). Results No marked differences in the general pattern of preferential collagen fibril orientation were noted between the control and affected dogs. The peripapillary sclera of all specimens featured strongly aligned circumferential collagen ringing the optic nerve head. Collagen anisotropy was significantly reduced in the mid-posterior sclera of the affected dogs (carrier: 0.27±0.11; affected: 0.24±0.10; p = 0.032) but was not statistically significantly different in the peripapillary sclera (carrier: 0.46±0.15; affected: 0.45±0.17; p = 0.68). Collagen density was statistically significantly reduced in the affected dogs for the mid-posterior sclera (carrier: 28.1±9.14; affected: 18.3±5.12; p<0.0001) and the peripapillary sclera (carrier: 34.6±9.34; affected: 21.1±6.97; p = 0.0002). Conclusions Significant alterations in the posterior scleral collagen microstructure are present before the onset of clinical glaucoma in ADAMTS10 mutant dogs. A reduction in fibrous collagen density is likely an important contributory factor in the previously reported mechanical weakening of the sclera in this model. Baseline scleral abnormalities have the potential to interact with intraocular pressure (IOP) elevations in determining the course of glaucoma progression in animal models of the disease, and potentially in human glaucoma. PMID:27212875

  7. A new surgical technique using steel suture for trans-scleral fixation of posterior chamber intraocular lenses

    PubMed Central

    Ram, Jagat; Gupta, Nishant; Chaudhary, Manish; Verma, Neelam

    2013-01-01

    Background: A new emerging complication of trans-scleral fixation of posterior chamber (PC) intraocular lens (IOL) with polypropylene suture is high rates of spontaneous dislocation of the IOL due to disintegration or breakage of suture. Materials: We report a new surgical technique of trans-scleral fixation of posterior chamber intraocular lens (SF PCIOL) with steel suture to eliminate the complication of dislocation of IOL fixed with polypropylene suture in one adult and a child. Results: We successfully achieved stable fixation and good centration of IOL after SF PCIOL with steel suture in these patient having inadequate posterior capsular support. Both eyes achieved best corrected visual acuity 20/40 at 18 months follow-up. Conclusions: Steel suture is a viable option for trans-scleral fixation of posterior chamber intraocular lens. PMID:23619504

  8. The Outcomes of Primary Scleral Buckling during Repair of Posterior Segment Open-Globe Injuries

    PubMed Central

    Cohen, Dan; Lifshitz, Tova; Belfair, Nadav; Klemperer, Itamar; Yanculovich, Noam

    2014-01-01

    Objective. To compare visual outcomes of eyes which underwent primary scleral buckling (PSB) treatment during posterior segment open-globe injury (OGI) repair with eyes not treated with PSB. Methods. We retrospectively reviewed 38 eyes which underwent a posterior segment OGI repair with no preoperative evidence of retinal detachment (RD) at Soroka University Medical Center (1995–2010). 19 (50%) underwent scleral repair alone (control group) and the other 19 eyes were treated with PSB also (PSB group). We compared visual outcomes in these two groups and rates of subsequent postoperative complications. Results. Baseline characteristics of the groups were similar. Compared with the control group, the PSB group had statistically significant lower rates of proliferative vitreoretinopathy (PVR) (5.3% versus 38.4%, P < 0.05) and a trend towards lower rates of RD (15.8% versus 41.1%, P = 0.1). PSB group eyes had a statistically significant improvement of their best distance visual acuity (BDVA) with lower means of final BDVA-grade (P < 0.05) and logMAR vision (P < 0.05). Eyes in the control group had no improvement in these parameters. Conclusion. PSB procedure during posterior segment OGI repair may decrease the risk of subsequent retinal complications and improve final visual outcome. PMID:25050367

  9. Unilateral Scleral Fixation of Posterior Chamber Intraocular Lenses in Pediatric Complicated Traumatic Cataracts

    PubMed Central

    Hyun, Dong Won; Cho, Sung Won

    2009-01-01

    Purpose The purpose of this study was to evaluate the visual outcomes and complications of unilateral scleral fixation of posterior chamber intraocular lenses (SF-PCIOLs) in pediatric complicated traumatic cataracts without capsular support. Methods This study involved five eyes of five children who underwent unilateral SF-PCIOL. All patients had a unilateral complicated traumatic cataract associated with anterior or posterior segment injury. Visual acuity (VA), IOL position, and postoperative complications were assessed during follow-up. Results The mean age of patients at the time of SF-PCIOL was 90 months (range, 66-115). The mean duration of follow-up time after surgery was 22 months (range, 5-55). In all patients, the best-corrected VA was either improved or was stable at last follow-up following SF-PCIOL implantation. There were no serious complications. Conclusions Unilateral scleral fixation of PCIOL can be a safe and effective procedure for pediatric, unilateral, complicated traumatic cataracts without capsular support in selected cases. PMID:19794939

  10. Clinical Investigation of the Posterior scleral contraction to Treat Macular Traction Maculopathy in Highly Myopic Eyes

    PubMed Central

    Pan, An-Peng; Wan, Ting; Zhu, Shuang-Qian; Dong, Liang; Xue, An-Quan

    2017-01-01

    Myopic traction maculopathy (MTM) can cause vision disabilities in highly myopic eyes. This retrospective case series investigated the clinical outcomes of posterior scleral contraction (PSC) using genipin-cross-linked sclera as the material to treat MTM in highly myopic eyes. In total, 32 eyes from 29 highly myopic patients who underwent PSC for MTM were recruited. The changes in best-corrected visual acuity (BCVA) and axial length were evaluated, macular reattachment and macular hole (MH) closure was assessed by optical coherence tomography, and complications were evaluated. At the final follow-up, the retina was completely reattached in 25 eyes (78.1%), essentially reattached in 4 eyes (12.5%), and partially reattached in 3 eyes (9.4%). The logMAR BCVA improved significantly from 1.18 ± 0.45 preoperatively to 0.87 ± 0.45 postoperatively (P < 0.001). The 32 eyes were further divided into the MH group (16 eyes) and the non-MH group (16 eyes) for comparison. The MH was closed in 9 eyes (56.3%). The retinal reattachment rate was 75.0% in the MH group and 81.25% in the non-MH group, and the logMAR BCVA improved significantly in both groups. The PSC using genipin-cross-linked sclera as the material can effectively treat MTM in highly myopic eyes, and significant visual improvement can be achieved with minimal complications. PMID:28220890

  11. Application of optical coherence tomography angiography in assessment of posterior scleral reinforcement for pathologic myopia

    PubMed Central

    Mo, Jing; Duan, An-Li; Chan, Szy-Yann; Wang, Xue-Fei; Wei, Wen-Bin

    2016-01-01

    AIM To investigate the effect of posterior scleral reinforcement (PSR) on circulation of pathologic myopia eyes with posterior staphyloma by optical coherence tomography angiography (OCTA). METHODS The study included 30 pathologic myopia eyes with posterior staphyloma which underwent PSR (PSR group) for 6 to 18mo ago, and 30 age and myopia matched eyes without PSR surgery as control group. Macular, choriocapillaris and radial peripapillary capillary (RPC) flow density were measured by OCTA, and the measurements were compared between groups. RESULTS OCTA found no significant differences in macular flow density between PSR and control groups. For the superficial flow, whole enface flow density (WED), fovea density (FD), and parafoveal density (PD) were 46.55%±5.19% vs 47.29%±4.12% (P=0.542), 31.45%±6.35% vs 31.17%±4.48% (P=0.841), and 48.82%±5.66% vs 49.21%±4.15% (P=0.756) in PSR and control groups, respectively. For the deep flow, WED, FD, and PD were 52.07%±5.78% vs 53.95%±4.62% (P=0.168), 29.62%±6.55% vs 29.50%±6.38% (P=0.940), and 56.93%±6.17% vs 58.15%±5.13% (P=0.407) in PSR and control groups, respectively. The choriocapillary flow density was 61.18±3.25% in PSR group vs 60.88%±2.56% in control group (P=0.692). Also, OCTA found no significant differences in RPCs flow density between PSR and control groups. The optic disc WED, inside disc flow density and peripapillary flow density were 48.47%±4.77% vs 48.11%±4.57% (P=0.813), 45.47%±11.44% vs 46.68%±9.02% (P=0.709), 54.32%±5.29% vs 52.47%±6.62% (P=0.349) in PSR and control groups, respectively. CONCLUSION OCTA provides a non-invasive and quantitative approach for monitoring macular and papillary blood flow in pathologic myopia. PSR can not improve but may maintain the circulation of pathologic myopia eyes with posterior staphyloma. PMID:28003976

  12. Ab-interno scleral suture loop fixation with cow-hitch knot in posterior chamber intraocular lens decentration

    PubMed Central

    Can, Ertuğrul; Koçak, Nurullah; Yücel, Özlem Eşki; Gül, Adem; Öztürk, Hilal Eser; Sayın, Osman

    2016-01-01

    Aim of Study: To describe a simplified ab-interno cow-hitch suture fixation technique for repositioning decentered posterior chamber intraocular lens (PC IOL). Materials and Methods: Two cases are presented with the surgical correction of decentered and subluxated IOL. Ab-interno scleral suture fixation technique with hitch-cow knot in the eye was performed with a ciliary sulcus guide instrument and 1 year follow-up was completed. Results: Both of the patients had well centered lenses postoperatively. Corrected distant and near visual acuities of the patients were improved. There was no significant postoperative complication. In the follow-up period of 1 year, no evidence of suture erosion was found. Conclusions: Ab-interno scleral suture loop fixation with hitch-cow knot in the eye was effective in repositioning decentered or subluxated PC IOLs with excellent postoperative centered lenses and visual outcomes. PMID:27050346

  13. Comparison of outcomes of primary and secondary implantation of scleral fixated posterior chamber intraocular lens

    PubMed Central

    Lee, V Y W; Yuen, H K L; Kwok, A K H

    2003-01-01

    Aim: To assess and compare the results of primary and secondary implantation of scleral fixated posterior chamber intraocular lens (SFIOL). Methods: The medical records of a consecutive series of 55 eyes of 55 patients with SFIOLs implanted during (group 1) or after (group 2) complicated senile cataract surgery were retrospectively reviewed and analysed. Results: There were 30 and 25 eyes in group 1 and 2, respectively. Follow up was from 6 to 36 months. Mean logMAR postoperative best corrected visual acuity in group 1 was not significantly different (0.50 (SD 0.36)) from that of group 2 (0.36 (0.21)) (p = 0.109). Postoperative best corrected visual acuity of 6/12 or better was achieved in 58.6% and 76.0% in group 1 and 2, respectively. The difference was not statistically significant (p = 0.177). In group 1, 25 (83.3%) eyes had a total of 55 early complications, while in group 2, 16 (64%) eyes had 26 early complications (p = 0.028). The difference in early complication was statistically significant. For late complication after 1 month, 21 (70.0%) eyes had a total of 37 complications in group 1, while 13 eyes (52.0%) had 19 complications in group 2 (p = 0.077). The difference in late complication was not statistically significant. Conclusion: Secondary implantation of SFIOL after cataract extraction seems to have a lower early complication rate than primary implantation in complicated cataract extraction although the final visual acuity and late complication rate are not significantly different. PMID:14660452

  14. A Forward Incremental Prestressing Method with Application to Inverse Parameter Estimations and Eye-Specific Simulations of Posterior Scleral Shells

    PubMed Central

    Downs, J. Crawford

    2012-01-01

    Numerical simulations or inverse numerical analyses of individual eyes or eye segments are often based on an eye-specific geometry obtained from in vivo medical images such as CT scans or from in vitro 3D digitizer scans. These eye-specific geometries are usually measured while the eye is subjected to internal pressure. Due to the nonlinear stiffening of the collagen fibril network in the eye, numerical incorporation of the pre-existing stress/strain state may be essential for realistic eye-specific computational simulations. Existing prestressing methods either compute accurate predictions of the prestressed state or guarantee a unique solution. In this contribution, a forward incremental pre-stressing method is presented that unifies the advantages of the existing approaches by providing accurate and unique predictions of the pre-existing stress/strain state at the true measured geometry. The impact of prestressing is investigated on (i) the inverse constitutive parameter identification of a synthetic sclera inflation test and (ii) an eye-specific simulation that estimates the realistic mechanical response of a preloaded posterior monkey scleral shell. Evaluation of the pre-existing stress/strain state in the inverse analysis had a significant impact on the reproducibility of the constitutive parameters but may be estimated based on an approximative approach. The eye-specific simulation of one monkey eye shows that prestressing is required for accurate displacement and stress/strain predictions. The numerical results revealed an increasing error in displacement, strain and stress predictions with increasing pre-existing pressure load when the pre-stress/strain state is disregarded. Disregarding the prestress may lead to a significant underestimation of the strain/stress environment in the sclera and overestimation in the lamina cribrosa. PMID:22224843

  15. Regional Variations in Mechanical Strain in the Posterior Human Sclera

    PubMed Central

    Fazio, Massimo A.; Grytz, Rafael; Bruno, Luigi; Girard, Michael J. A.; Gardiner, Stuart; Girkin, Christopher A.; Downs, J. Crawford

    2012-01-01

    Purpose. The goal of this study was to establish sectorial and regional variability in the mechanical strain of peripapillary and mid-peripheral sclera in normal eyes from elderly human donors. Methods. Ten pairs of normal eyes from human donors aged 57 to 90 years old were mechanically inflation-tested within 48 hours post mortem. The intact posterior scleral shells were pressurized from 5 to 45 mm Hg while the full-field three-dimensional displacements of the scleral surface were measured using laser speckle interferometry. The displacement field was fit to continuous and differentiable analytical functions, from which the full strain tensor of the outer scleral surface was calculated. Mean maximum principal (tensile) strain was computed for eight circumferential sectors (45° wide) within the peripapillary and mid-peripheral regions surrounding the optic nerve head (ONH). Results. Overall, the peripapillary sclera exhibited significantly higher tensile strain (1.2%) than mid-peripheral sclera (0.95%) for a 40 mm Hg IOP elevation (P < 0.00001). In the peripapillary region, the inferotemporal sector exhibited the highest tensile strain (1.45%) while the superior sector had the lowest (1.19%; P < 0.00001). Mid-peripheral scleral strains were lower but exhibited a similar sectorial pattern. Conclusions. Human posterior sclera exhibits complex regional mechanical behavior in response to acute IOP elevations from 5 to 45 mm Hg. Results indicate 1) the peripapillary sclera is subjected to significantly higher tensile strain than the adjacent mid-peripheral sclera, and 2) strains are significantly higher in the temporal and inferior quadrants of the peripapillary sclera, which may contribute to the increased prevalence of glaucomatous damage associated with these regions of the ONH. PMID:22700704

  16. Long-term safety of polypropylene knots under scleral flaps for transsclerally sutured posterior chamber lenses.

    PubMed Central

    Van Meter, W S

    1997-01-01

    PURPOSE: To evaluate the safety of polypropylene knots used in TS-SPCL combined with PK and AV over time. METHOD: A retrospective review of 26 consecutive cases of TS-SPCL by one surgeon (WSVM) with at least 12 months follow-up (mean 26, range 12-62). All patients had a double strand polypropylene knot buried under partial thickness scleral flaps at 2 and 8 o'clock. Knots were rotated into the globe (R) in 10 cases, and could not be buried (N) in 13 cases, and in 3 cases 1 knot was buried. RESULTS: No cases of suture erosion occurred in R or N. One or more polypropylene sutures were visible in 17 patients (8 R, 9 T) at last exam. Twenty-three of 52 knots were rotated into the globe, and 70% of rotated knots were not even visible at the slit lamp at final visit. There was no evidence of conjunctival erosion in any patient. There was no lens dislocation and no endophthalmitis. CONCLUSION: The combination of partial thickness scleral flaps with double strand polypropylene knots reduces the incidence of suture erosion through the conjunctive if knots cannot be rotated into the globe. Images FIGURE 1 FIGURE 2 FIGURE 3 PMID:9440177

  17. Comparative effects of posterior eye cup tissues from myopic and hyperopic chick eyes on cultured scleral fibroblasts.

    PubMed

    Christian, Parul G; Harkin, Damien G; Rayner, Cassie; Schmid, Katrina L

    2013-02-01

    The role of individual ocular tissues in mediating changes to the sclera during myopia development is unclear. The aim of this study was to examine the effects of retina, RPE and choroidal tissues from myopic and hyperopic chick eyes on the DNA and glycosaminoglycan (GAG) content in cultures of chick scleral fibroblasts. Primary cultures of fibroblastic cells expressing vimentin and α-smooth muscle actin were established in serum-supplemented growth medium from 8-day-old normal chick sclera. The fibroblasts were subsequently co-cultured with posterior eye cup tissue (full thickness containing retina, RPE and choroid) obtained from untreated eyes and eyes wearing translucent diffusers (form-deprivation myopia, FDM) or -15D lenses (lens-induced myopia, LIM) for 3 days (post-hatch day 5-8) (n = 6 per treatment group). The effect of tissues (full thickness and individual retina, RPE, and choroid layers) from -15D (LIM) versus +15D (lens-induced hyperopia, LIH) treated eyes was also determined. Refraction changes in the direction predicted by the visual treatments were confirmed by retinoscopy prior to tissue collection. Glycosaminoglycan (GAG) and DNA content of the scleral fibroblast cultures were measured using GAG and PicoGreen assays. There was no significant difference in the effect of full thickness tissue from either FDM or LIM treated eyes on DNA and GAG content of scleral fibroblasts (DNA 8.9 ± 2.6 μg and 8.4 ± 1.1 μg, p = 0.12; GAG 11.2 ± 0.6 μg and 10.1 ± 1.0 μg, p = 0.34). Retina from LIM eyes did not alter fibroblast DNA or GAG content compared to retina from LIH eyes (DNA 27.2 ± 1.7 μg versus 23.2 ± 1.5 μg, p = 0.21; GAG 28.1 ± 1.7 μg versus. 28.7 ± 1.2 μg, p = 0.46). Similarly, the choroid from LIH and LIM eyes did not produce a differential effect on DNA content (DNA LIM 46.9 ± 6.4 versus LIH 51.5 ± 4.7 μg, p = 0.31). In contrast, scleral fibroblast DNA was greater in co-culture with RPE from LIM eyes than the empty basket and DNA

  18. Retinectomy vs vitrectomy combined with scleral buckling in repair of posterior segment open-globe injuries with retinal incarceration.

    PubMed

    Wei, Y; Zhou, R; Xu, K; Wang, J; Zu, Z

    2016-05-01

    PurposeTo evaluate the anatomic and functional outcome of pars plana vitrectomy (PPV) combined with scleral buckling (SB) vs retinectomy in treating posterior segment open-globe injuries with retinal incarceration.MethodsPatients (38 eyes) with posterior segment open-globe injuries and retinal incarceration were identified, and they underwent either PPV combined with SB (PPV+SB, n=19) or retinectomy (n=19). The two groups were matched in the following categories: the severity of injury (including wound length), the location of the incarceration site and the presence of retinal detachment. Anatomic reattachment of the retina and best-corrected visual acuity (BCVA) were measured at the time of 12 months after operation.ResultsAt 12 months after operation, the PPV+SB group demonstrated a better anatomic retinal attachment rate (84.2% vs 68.4%, P=0.252) and BCVA (73.7% vs 47.4%, P=0.247) compared with the retinectomy group, however, the differences failed to reach statistical significance. Compared with the PPV+SB group, the rectinectomy group had significantly higher rates of hemorrhage (47.4% vs 15.8%, P=0.036), inflammation (42.1% vs 10.5%, P=0.027), and a lower intraocular pressure (IOP, 9.8±3.1 vs 13.6±4.1 mmHg, P=0.002) after silicone oil (SO) removal.ConclusionsFor patients with posterior segment open-globe injuries and retinal incarceration, PPV and SB treatments resulted in a better anatomic and functional outcome and less post-operation complications compared with the retinectomy.

  19. The effects of glycosaminoglycan degradation on the mechanical behavior of the posterior porcine sclera

    PubMed Central

    Murienne, Barbara J.; Jefferys, Joan L.; Quigley, Harry A.; Nguyen, Thao D.

    2014-01-01

    Pathological changes in scleral glycosaminoglycan (GAG) content and in scleral mechanical properties have been observed in eyes with glaucoma and myopia. The purpose of this study is to investigate the effect of GAG removal on the scleral mechanical properties to better understand the impact of GAG content variations in the pathophysiology of glaucoma and myopia. We measured how the removal of sulphated GAG (s-GAG) affected the hydration, thickness and mechanical properties of the posterior sclera in enucleated eyes of 6–9 month-old pigs. Measurements were made in 4 regions centered on the optic nerve head (ONH) and evaluated under 3 conditions: no treatment (control), after treatment in buffer solution alone, and after treatment in buffer containing chondroitinase ABC (ChABC) to remove s-GAGs. The specimens were mechanically tested by pressure-controlled inflation with full-field deformation mapping using digital image correlation (DIC). The mechanical outcomes described the tissue tensile and viscoelastic behavior. Treatment with buffer alone increased the hydration of the posterior sclera compared to controls, while s-GAG removal caused a further increase in hydration compared to buffer-treated scleras. Buffer-treatment significantly changed the scleral mechanical behavior compared to the control condition, in a manner consistent with an increase in hydration. Specifically, buffer-treatment led to an increase in low-pressure stiffness, hysteresis, and creep rate, and a decrease in high-pressure stiffness. ChABC-treatment on buffer-treated scleras had opposite mechanical effects than buffer-treatment on controls, leading to a decrease in low-pressure stiffness, hysteresis, and creep rate, and an increase in high-pressure stiffness and transition strain. Furthermore, s-GAG digestion dramatically reduced the differences in the mechanical behavior among the 4 quadrants surrounding the ONH as well as the differences between the circumferential and meridional

  20. The effects of glycosaminoglycan degradation on the mechanical behavior of the posterior porcine sclera.

    PubMed

    Murienne, Barbara J; Jefferys, Joan L; Quigley, Harry A; Nguyen, Thao D

    2015-01-01

    Pathological changes in scleral glycosaminoglycan (GAG) content and in scleral mechanical properties have been observed in eyes with glaucoma and myopia. The purpose of this study is to investigate the effect of GAG removal on the scleral mechanical properties to better understand the impact of GAG content variations in the pathophysiology of glaucoma and myopia. We measured how the removal of sulphated GAG (s-GAG) affected the hydration, thickness and mechanical properties of the posterior sclera in enucleated eyes of 6-9 month-old pigs. Measurements were made in 4 regions centered on the optic nerve head (ONH) and evaluated under 3 conditions: no treatment (control), after treatment in buffer solution alone, and after treatment in buffer containing chondroitinase ABC (ChABC) to remove s-GAGs. The specimens were mechanically tested by pressure-controlled inflation with full-field deformation mapping using digital image correlation (DIC). The mechanical outcomes described the tissue tensile and viscoelastic behavior. Treatment with buffer alone increased the hydration of the posterior sclera compared to controls, while s-GAG removal caused a further increase in hydration compared to buffer-treated scleras. Buffer-treatment significantly changed the scleral mechanical behavior compared to the control condition, in a manner consistent with an increase in hydration. Specifically, buffer-treatment led to an increase in low-pressure stiffness, hysteresis, and creep rate, and a decrease in high-pressure stiffness. ChABC-treatment on buffer-treated scleras had opposite mechanical effects than buffer-treatment on controls, leading to a decrease in low-pressure stiffness, hysteresis, and creep rate, and an increase in high-pressure stiffness and transition strain. Furthermore, s-GAG digestion dramatically reduced the differences in the mechanical behavior among the 4 quadrants surrounding the ONH as well as the differences between the circumferential and meridional

  1. Material Properties of the Posterior Human Sclera☆

    PubMed Central

    Grytz, Rafael; Fazio, Massimo A.; Girard, Michael J.A.; Libertiaux, Vincent; Bruno, Luigi; Gardiner, Stuart; Girkin, Christopher A.; Downs, J. Crawford

    2013-01-01

    To characterize the material properties of posterior and peripapillary sclera from human donors, and to investigate the macro- and micro-scale strains as potential control mechanisms governing mechanical homeostasis. Posterior scleral shells from 9 human donors aged 57–90 years were subjected to IOP elevations from 5 to 45 mmHg and the resulting full-field displacements were recorded using laser speckle interferometry. Eye-specific finite element models were generated based on experimentally measured scleral shell surface geometry and thickness. Inverse numerical analyses were performed to identify material parameters for each eye by matching experimental deformation measurements to model predictions using a microstructure-based constitutive formulation that incorporates the crimp response and anisotropic architecture of scleral collagen fibrils. The material property fitting produced models that fit both the overall and local deformation responses of posterior scleral shells very well. The nonlinear stiffening of the sclera with increasing IOP was well reproduced by the uncrimping of scleral collagen fibrils, and a circumferentially-aligned ring of collagen fibrils around the scleral canal was predicted in all eyes. Macroscopic in-plane strains were significantly higher in peripapillary region then in the mid-periphery. In contrast, the meso- and micro-scale strains at the collagen network and collagen fibril level were not significantly different between regions. The elastic response of the posterior human sclera can be characterized by the anisotropic architecture and crimp response of scleral collagen fibrils. The similar collagen fibril strains in the peripapillary and mid-peripheral regions support the notion that the scleral collagen architecture including the circumpapillary ring of collagen fibrils evolved to establish optimal load bearing conditions at the collagen fibril level. PMID:23684352

  2. [Endoscopically controlled optimization of trans-scleral suture fixation of posterior chamber lenses in the ciliary sulcus].

    PubMed

    Althaus, C; Sundmacher, R

    1993-08-01

    Two technical difficulties have to be overcome in transscleral suture fixation of posterior chamber intraocular lenses (PCL) in the ciliary sulcus: first, exact needle penetration through the sulcus, and second, exact positioning of the PCL haptics in the sulcus. Incongruence of the two may lead to long-term complications by compression or even strangulation of ciliary processes. Intraocular endoscopy was used intraoperatively to visualize the site of needle penetration and the final location of the haptics in patients. It turned out that with our previously described standard techniques the precision was far less than anticipated. Thus, new technical ways had to be sought to improve the precision of positioning. In secondary implantation without perforating keratoplasty we achieved the best results when the needle was passed ab externo before opening the eye and before anterior vitrectomy, taking advantage of a precisely prepared sclerocorneal zone. Passing the needle ab externo in an already hypotonic eyeball gives much less precise results. In combination with perforating keratoplasty with an open-sky approach, needle penetration ab interno is reliable. Correct positioning of the PCL haptics is at least as difficult as correct needle penetration, a fact which up to now has mostly been ignored. In 33 consecutively operated eyes the technique of implantation and PCL design was varied under endoscopical control.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Intact Globe Inflation Testing of Changes in Scleral Mechanics in Myopia and Recovery

    PubMed Central

    Lewis, Jacob A.; Garcia, Mariana B.; Rani, Lakshmisahithi; Wildsoet, Christine F.

    2014-01-01

    The purpose of this study was to examine the effects of myopia-inducing and myopia recovery conditions on the scleral biomechanics of enucleated eyes of young chicks. Enucleated eyes from 5-day old chicks, with fiducial markers attached at 5 locations on the external sclera, were placed in a custom-built chamber filled with phosphate-buffered saline, and subjected to controlled increments in intraocular pressure (IOP). IOP was initially ramped from 15 to 100 mmHg and then maintained at 100 mmHg for one hour, with eyes photographed at a rate of 0.1 Hz over the same period. There were two experimental groups, one in which chicks were monocularly form deprived for four days to induce myopia, and the other in which chicks were allowed two days of recovery from myopia induced by two days of form deprivation. For all chicks, the contralateral (fellow) eyes served as controls. Myopic eyes showed less initial deformation relative to their fellows, while no difference was recorded between recovering eyes and their fellows over the same time frame. With exposure to sustained elevated pressure, eyes in all groups displayed time-dependent changes in creep behavior, which included a linear region of secondary, steady creep. The creep deformation of myopic eyes was significantly higher than that of their fellows, consistent with results of previous studies using uniaxial loading of scleral strips. When allowed only 2 days to recover from induced myopia, previously myopic eyes continued to show increased creep deformation. Compared to results reported in studies involving scleral strips, our whole globe testing yielded higher values for creep rate. Whole globe inflation testing provides a viable, less anatomically disruptive and readily adaptable method for investigating scleral biomechanics than uniaxial tensile strip testing. Furthermore, our results suggest that elastic stretching does not contribute to the increased axial elongation underlying myopia in young chick eyes. They

  4. [A preliminary study on macular retinal and choroidal thickness and blood flow change after posterior scleral reinforcement by optical coherence tomography angiography].

    PubMed

    Zhang, X F; Qiao, L Y; Li, X X; Ma, N; Li, M; Guan, Z; Wang, H Z; Wang, N L

    2017-01-11

    Objective: To investigate macular retinal and choroidal thickness and blood flow change using optical coherence tomography angiography after posterior scleral reinforcement (PSR) surgery. Methods: Prospective study. Twenty eyes of 10 patients with high myopia were enrolled in this open-label, single-treatment group and prospective study. Radial lines and Angio retina (3 mm×3 mm) module were performed for 20 eyes using Angio-vue optical coherence tomography (Avanti, Optovue) without pupil dilation, and best corrected visual acuity, spherical equivalent and axial length were compared before and 60 days after surgery. Retinal and choroidal thickness was measured in the fovea, 1 mm superior, 1 mm inferior, 1 mm nasal and 1 mm temporal to the fovea. Flow area, flow density and flow index were recorded using self-provided software in the superficial retina layer, deep retina layer, outer retina layer and choroid capillary layer, respectively. Statistical analysis was performed using SPSS 16.0. Data that followed normal distribution were compared with paired two-sample t-test, while others were compared with Wilcoxon signed rank test. Results: Of the patients participating in this preliminary study, the mean age was (35.5±4.2) years, and 50% were female. No significant difference was found between before and 60 days after PSR surgery in best corrected visual acuity (t=0.99, P=0.33), spherical equivalent (t=-1.89, P=0.07) and axial length (t=0.2, P=0.08). The retinal thickness in the fovea was thinner (Z=-2.58, P=0.01), while there was no significant difference in the 1 mm superior (t=0.44, P=0.67) , 1 mm inferior (t=0.05, P=0.96) , 1 mm nasal (Z=0.87, P=0.64) and 1 mm temporal (Z=-0.78, P=0.99) to the fovea. No significant difference was found in choroidal thickness (t=-0.12, P=0.87; t=-0.25, P=0.81. t=0.53, P=0.61; t=-0.91, P=0.38. t=1.2, P=0.25) before and after surgery. The postoperative flow density in the superficial and deep retinal layers (48.18±4.56% and 31.47

  5. Enhancement of scleral macromolecular permeability with prostaglandins.

    PubMed Central

    Weinreb, R N

    2001-01-01

    PURPOSE: It is proposed that the sclera is a metabolically active and pharmacologically responsive tissue. These studies were undertaken to determine whether prostaglandin exposure can enhance scleral permeability to high-molecular-weight substances. METHODS: Topical prostaglandin F2 alpha (PGF2 alpha) was administered to monkeys to determine if this altered the amount of scleral matrix metalloproteinases (MMPs). Experiments also were performed to determine whether the prostaglandin F (FP) receptor and gene transcripts are expressed in normal human sclera. Permeability of organ-cultured human sclera following prostaglandin exposure then was studied and the amount of MMP released into the medium measured. Finally, the permeability of human sclera to basic fibroblast growth factor (FGF-2) was determined following prostaglandin exposure. RESULTS: Topical prostaglandin administration that reduced scleral collagen also increased scleral MMP-1, MMP-2, and MMP-3 by 63 +/- 35%, 267 +/- 210%, and 729 +/- 500%, respectively. FP receptor protein was localized in scleral fibroblasts, and FP receptor gene transcript was identified in sclera. Exposure to prostaglandin F2 alpha, 17-phenyltrinor, PGF2 alpha, or latanoprost acid increased scleral permeability by up to 124%, 183%, or 213%, respectively. In these cultures, MMP-1, MMP-2, and MMP-3 were increased by up to 37%, 267%, and 96%, respectively. Finally, transscleral absorption of FGF-2 was increased by up to 126% with scleral exposure to latanoprost. CONCLUSIONS: These studies demonstrate that the sclera is metabolically active and pharmacologically responsive to prostaglandins. Further, they demonstrate the feasibility of cotreatment with prostaglandin to enhance transscleral delivery of peptides, such as growth factors and high-molecular-weight substances, to the posterior segment of the eye. PMID:11797317

  6. Scleral Buckling with Chandelier Illumination.

    PubMed

    Seider, Michael I; Nomides, Riikka E K; Hahn, Paul; Mruthyunjaya, Prithvi; Mahmoud, Tamer H

    2016-01-01

    Scleral buckling is a highly successful technique for the repair of rhegmatogenous retinal detachment that requires intra-operative examination of the retina and treatment of retinal breaks via indirect ophthalmoscopy. Data suggest that scleral buckling likely results in improved outcomes for many patients but is declining in popularity, perhaps because of significant advances in vitrectomy instrumentation and visualization systems. Emerging data suggest that chandelier-assisted scleral buckling is safe and has many potential advantages over traditional buckling techniques. By combining traditional scleral buckling with contemporary vitreoretinal visualization techniques, chandelier-assistance may increase the popularity of scleral buckling to treat primary rhegmatogenous retinal detachment for surgeons of the next generation, maintaining buckling as an option for appropriate patients in the future.

  7. Scleral Buckling with Chandelier Illumination

    PubMed Central

    Seider, Michael I.; Nomides, Riikka E. K.; Hahn, Paul; Mruthyunjaya, Prithvi; Mahmoud, Tamer H.

    2016-01-01

    Scleral buckling is a highly successful technique for the repair of rhegmatogenous retinal detachment that requires intra-operative examination of the retina and treatment of retinal breaks via indirect ophthalmoscopy. Data suggest that scleral buckling likely results in improved outcomes for many patients but is declining in popularity, perhaps because of significant advances in vitrectomy instrumentation and visualization systems. Emerging data suggest that chandelier-assisted scleral buckling is safe and has many potential advantages over traditional buckling techniques. By combining traditional scleral buckling with contemporary vitreoretinal visualization techniques, chandelier-assistance may increase the popularity of scleral buckling to treat primary rhegmatogenous retinal detachment for surgeons of the next generation, maintaining buckling as an option for appropriate patients in the future. PMID:27621789

  8. Neck and scleral hemorrhage in drowning.

    PubMed

    Alexander, Russell T; Jentzen, Jeffrey M

    2011-03-01

    The determination of the cause and manner of death for a body recovered from the water can be difficult because of a lack of autopsy findings specific for drowning. This case report describes a 30-year-old man found submerged at the bottom of a hotel pool. An autopsy revealed scleral hemorrhages and fascial hemorrhages of multiple muscles of the anterior and posterior neck bilaterally. No evidence of traumatic injury was on the surface of the body. An investigation by law enforcement found no evidence of foul play. The occurrence of petechial and neck hemorrhage in a body recovered from the water is controversial, and a review of this literature will be given. We suggest that fascial hemorrhages of the muscles of the neck, as well as cephalic hemorrhages, can be explained by drowning-related elevated central venous pressure that is communicated to the head through the valveless veins of the neck.

  9. Mitral Valve Mechanics Following Posterior Leaflet Patch Augmentation

    PubMed Central

    Rahmani, Azadeh; Rasmussen, Ann Q.; Honge, Jesper L.; Ostli, Bjorn; Levine, Robert A.; Hagège, Albert; Nygaard, Hans; Nielsen, Sten L.; Jensen, Morten O.

    2013-01-01

    Background and aim of the study Attention towards the optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy used to treat functional ischemic mitral regurgitation (FIMR). The study aim was to investigate the force balance changes in specific chordae tendineae emanating from the posterior papillary muscle in a FIMR-simulated valve, following posterior leaflet patch augmentation. Methods Mitral valves were obtained from 12 pigs (body weight 80 kg). An in vitro test set-up simulating the left ventricle was used to hold the valves. The left ventricular pressure was regulated with water to simulate different static pressures during valve closure. A standardized oval pericardial patch (17 × 29 mm) was introduced into the posterior leaflet from mid P2 to the end of the P3 scallop. Dedicated miniature transducers were used to record the forces exerted on the chordae tendineae. Data were acquired before and after 12 mm posterior and 5 mm apical posterior papillary muscle displacement to simulate the effect from one of the main contributors of FIMR, before and after patch augmentation. Results The effect of displacing the posterior papillary muscle induced tethering on the intermediate chordae tendineae to the posterior leaflet, and resulted in a 39.8% force increase (p = 0.014). Posterior leaflet patch augmentation of the FIMR valve induced a 31.1% force decrease (p = 0.007). There was no difference in force between the healthy and the repaired valve simulations (p = 0.773). Conclusion Posterior leaflet patch augmentation significantly reduced the forces exerted on the intermediate chordae tendineae from the posterior papillary muscle following FIMR simulation. As changes in chordal tension lead to a redistribution of the total stress exerted on the valve, patch augmentation may have an adverse long-term influence on mitral valve function and remodeling. PMID:23610985

  10. Longterm remission of left posterior fascicular ventricular tachycardia due to mechanical trauma.

    PubMed

    Parizek, Petr; Popelka, Jiri; Haman, Ludek

    2010-08-01

    We present a case of a 28 year old woman with paroxysmal left posterior fascicular ventricular tachycardia (LPFVT). Ventricular tachycardia was not inducible after completing of left ventricle 3D reconstruction. Even though catheter ablation was not performed, no LPFVT recurrence has been documented during 60 months follow-up. We surmise that we caused mechanical trauma during the mapping of the posterior fascicle that damaged arrhythmogenic structures and subsequently led to long term remission of the left posterior fascicular ventricular tachycardia.

  11. Two – three loci control scleral ossicle formation via epistasis in the cavefish Astyanax mexicanus

    PubMed Central

    Lyon, Anastasia; Powers, Amanda K.; Gross, Joshua B.; O’Quin, Kelly E.

    2017-01-01

    The sclera is the protective outer layer of the eye. In fishes, birds, and reptiles, the sclera may be reinforced with additional bony elements called scleral ossicles. Teleost fish vary in the number and size of scleral ossicles; however, the genetic mechanisms responsible for this variation remain poorly understood. In this study, we examine the inheritance of scleral ossicles in the Mexican tetra, Astyanax mexicanus, which exhibits both a cave morph and a surface fish morph. As these morphs and their hybrids collectively exhibit zero, one, and two scleral ossicles, they represent a microcosm of teleost scleral ossicle diversity. Our previous research in F2 hybrids of cavefish from Pachón cave and surface fish from Texas suggested that three genes likely influence the formation of scleral ossicles in this group through an epistatic threshold model of inheritance, though our sample size was small. In this study, we expand our sample size using additional hybrids of Pachón cavefish and Mexican surface fish to (1) confirm the threshold model of inheritance, (2) refine the number of genes responsible for scleral ossicle formation, and (3) increase our power to detect quantitative trait loci (QTL) for this trait. To answer these three questions, we scored surface fish and cavefish F2 hybrids for the presence of zero, one, or two scleral ossicles. We then analyzed their distribution among the F2 hybrids using a chi-square (χ2) test, and used a genetic linkage map of over 100 microsatellite markers to identify QTL responsible for scleral ossicle number. We found that inheritance of scleral ossicles follows an epistatic threshold model of inheritance controlled by two genes, which contrasts the three-locus model estimated from our previous study. Finally, the combined analysis of hybrids from both crosses identified two strong QTL for scleral ossicle number on linkage groups 4.2 and 21, and a weaker QTL on linkage group 4.1. Scleral ossification remains a complex

  12. Modern scleral contact lenses: A review.

    PubMed

    van der Worp, Eef; Bornman, Dina; Ferreira, Daniela Lopes; Faria-Ribeiro, Miguel; Garcia-Porta, Nery; González-Meijome, José M

    2014-08-01

    Scleral contact lenses (ScCL) have gained renewed interest during the last decade. Originally, they were primarily used for severely compromised eyes. Corneal ectasia and exposure conditions were the primary indications. However, the indication range of ScCL in contact lens practices seems to be expanding, and it now increasingly includes less severe and even non-compromised eyes, too. All lenses that partly or entirely rest on the sclera are included under the name ScCL in this paper; although the Scleral Lens Education Society recommends further classification. When a lens partly rests on the cornea (centrally or peripherally) and partly on the sclera, it is called a corneo-scleral lens. A lens that rests entirely on the sclera is classified as a scleral lens (up to 25 mm in diameter maximum). When there is full bearing on the sclera, further distinctions of the scleral lens group include mini-scleral and large-scleral lenses. This manuscript presents a review of the current applications of different ScCL (all types), their fitting methods, and their clinical outcomes including potential adverse events. Adverse events with these lenses are rare, but the clinician needs to be aware of them to avoid further damage in eyes that often are already compromised. The use of scleral lenses for non-pathological eyes is discussed in this paper.

  13. 21 CFR 886.4155 - Scleral plug.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... stainless steel with or without a gold, silver, or titanium coating. The special controls for the surgical grade stainless steel scleral plug (with or without a gold, silver, or titanium coating) are: (i) The... titanium coating). The special controls for scleral plugs made of other materials are: (i) The device...

  14. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation.

    PubMed

    Horiguchi, Lie; Garcia, Patricia Novita; Malavazzi, Gustavo Ricci; Allemann, Norma; Gomes, Rachel L R

    2016-01-01

    Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound biomicroscopy (UBM). Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6%) and the ab interno in 8 eyes (53.3%). In the ab externo technique, 14 haptics were located: 4 (28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus, and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno.

  15. Scleral buckle infection by Serratia species

    PubMed Central

    Venkatesh, Ramesh; Agarwal, Manisha; Singh, Shalini; Mayor, Rahul; Bansal, Aditya

    2017-01-01

    We describe a rare case of scleral buckle (SB) infection with Serratia species. A 48-year-old male with a history of retinal detachment repair with scleral buckling presented with redness, pain, and purulent discharge in the left eye for 4 days. Conjunctival erosion with exposure of the SB and scleral thinning was noted. The SB was removed and sent for culture. Blood and chocolate agar grew Gram-negative rod-shaped bacillus identified as Serratia marcescens. On the basis of the susceptibility test results, the patient was treated with oral and topical antibiotics. After 6 weeks of the treatment, his infection resolved. PMID:28298863

  16. Age- and Race-Related Differences in Human Scleral Material Properties

    PubMed Central

    Grytz, Rafael; Fazio, Massimo A.; Libertiaux, Vincent; Bruno, Luigi; Gardiner, Stuart; Girkin, Christopher A.; Downs, J. Crawford

    2014-01-01

    Purpose. We tested the hypothesis that there are age- and race-related differences in posterior scleral material properties, using eyes from human donors of European (20–90 years old, n = 40 eyes) and African (23–74 years old, n = 22 eyes) descent. Methods. Inflation tests on posterior scleral shells were performed while full-field, three-dimensional displacements were recorded using laser speckle interferometry. Scleral material properties were fit to each eye using a microstructure-based constitutive formulation that incorporates the collagen fibril crimp and the local anisotropic collagen architecture. The effects of age and race were estimated using Generalized Estimating Equations, while accounting for intradonor correlations. Results. The shear modulus significantly increased (P = 0.038) and collagen fibril crimp angle significantly decreased with age (P = 0.002). Donors of African descent exhibited a significantly higher shear modulus (P = 0.019) and showed evidence of a smaller collagen fibril crimp angle (P = 0.057) compared to donors of European descent. The in-plane strains in the peripapillary sclera were significantly lower with age (P < 0.015) and African ancestry (P < 0.015). Conclusions. The age- and race-related differences in scleral material properties result in a loss of scleral compliance due to a higher shear stiffness and a lower level of stretch at which the collagen fibrils uncrimp. The loss of compliance should lead to larger high frequency IOP fluctuations and changes in the optic nerve head (ONH) biomechanical response in the elderly and in persons of African ancestry, and may contribute to the higher susceptibility to glaucoma in these at-risk populations. PMID:25389203

  17. Experimental Investigation on the Morphology and Adhesion Mechanism of Leech Posterior Suckers

    PubMed Central

    Dong, Wenhao

    2015-01-01

    The posterior sucker of a leech represents a fascinating natural system that allows the leech to adhere to different terrains and substrates. However, the mechanism of adhesion and desorption has not yet to be elucidated. In order to better understand how the adhesion is performed, we analyzed the surface structure, adsorption movements, the muscles’ distribution, physical characteristics, and the adsorption force of the leech posterior suckers by experimental investigation. Three conclusions can be drawn based on the obtained experimental results. First, the adhesion by the posterior sucker is wet adhesion, because the surface of the posterior sucker is smooth and the sealing can only be achieved on wet surfaces. Second, the deformation texture, consisting of soft collagen tissues and highly ductile epidermal tissues, plays a key role in adhering to rough surfaces. Finally, the adhesion and desorption is achieved by the synergetic operation of six muscle fibers working in different directions. Concrete saying, directional deformation of the collagen/epithermal interface driven by spatially-distributed muscle fibers facilitates the excretion of fluids in the sucker venter, thus allowing liquid sealing. Furthermore, we found that the adhesion strength is directly related to the size of the contact surface which is generated and affected by the sucker deformation. Such an underlying physical mechanism offers potential cues for developing innovative bio-inspired artificial adhesion systems. PMID:26536352

  18. Secretory mechanism of fibroin, a silk protein, in the posterior silk gland cells of Bombyx mori.

    PubMed

    Sasaki, S; Nakagaki, I

    1980-01-01

    There are two microtubule-microfilament systems in the posterior silk gland cells of Bombyx mori. One is a radial microtubule system; the other is a circular microtubule-microfilament system. These two systems are presumably concerned with the intracellular transport of secretory granules of fibroin and the secretion of fibroin into the lumen, respectively. Conventional and scanning electron microscopic observations of the two microtubule-microfilament systems in the posterior silk gland cells are reported. Scanning electron micrographs showed that a number of parallel linear cytoplasmic processes ran circularly on the luminal surface of the posterior silk gland cells. These processes were assumed to correspond to the circular microtubule-microfilament systems. The effects of cytochalasin (B or D), a secretion stimulating agent of fibroin, on the intracellular recording of membrane potential from the posterior silk gland cells are also reported. Exposure to cytochalasin resulted in depolarization of the membrane potential of the gland cells. Possible functional roles of the two microtubule-microfilament systems in the secretory mechanism of fibroin are discussed with reference to the effects of antimitotic reagents and cytochalasin on these two systems.

  19. 21 CFR 886.3300 - Absorbable implant (scleral buckling method).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Absorbable implant (scleral buckling method). 886.3300 Section 886.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... (scleral buckling method). (a) Identification. An absorbable implant (scleral buckling method) is a...

  20. 21 CFR 886.3300 - Absorbable implant (scleral buckling method).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Absorbable implant (scleral buckling method). 886.3300 Section 886.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... (scleral buckling method). (a) Identification. An absorbable implant (scleral buckling method) is a...

  1. Scleral lens for keratoconus: technology update

    PubMed Central

    Rathi, Varsha M; Mandathara, Preeji S; Taneja, Mukesh; Dumpati, Srikanth; Sangwan, Virender S

    2015-01-01

    Scleral lenses are large diameter lenses which rest over the sclera, unlike the conventional contact lenses which rest on the cornea. These lenses are fitted to not touch the cornea and there is a space created between the cornea and the lens. These lenses are inserted in the eyes after filling with sterile isotonic fluid. Generally, scleral contact lenses are used for high irregular astigmatism as seen in various corneal ectatic diseases such as keratoconus, pellucid marginal degeneration, or/and as liquid bandage in ocular surface disorders. In this article, we review the new developments, that have taken place over the years, in the field of scleral contact lenses as regard to new designs, materials, manufacturing technologies, and fitting strategies particularly for keratoconus. PMID:26604671

  2. Sequential-digital image correlation for mapping human posterior sclera and optic nerve head deformation.

    PubMed

    Pyne, Jeffrey D; Genovese, Katia; Casaletto, Luciana; Vande Geest, Jonathan P

    2014-02-01

    Optic nerve head (ONH) deformations may be involved in the onset or further development of glaucoma, including in patients with relatively normal intraocular pressures (IOPs). Characterizing posterior scleral deformations over physiological pressures may provide a better understanding of how changes in IOP lead to changes in the mechanical environment of the ONH and possibly retinal ganglion cell death. Pressure inflation measurement test protocols are commonly used to measure deformation of the peripapillary sclera with full-field noncontact optical methods. The purpose of this work was to develop and validate a new sequential 3D digital image correlation (S-DIC) approach for quantification of posterior scleral pressure induced deformation that improves z (in-depth) resolution of the DIC measurement without losing in-plane sensitivity, while also being able to contour and map deformations of the complex-shaped ONH. Our approach combines two orthogonal axes of parallax with standard 3D DIC methods using a single high-resolution camera. The enhanced capabilities of S-DIC with respect to standard 3D DIC has been demonstrated by carrying out a complete benchmark for shape, deformation, and strain measurement on an object of known complex geometry. Our S-DIC method provided a reconstruction accuracy of 0.17% and an uncertainty in z-position measurement of 8 μm. The developed methodology has also been applied to a human posterior scleral shell, including the full peripapillary sclera and optic nerve. The relatively inexpensive S-DIC approach may provide new information on the biomechanical deformations of the optic nerve head and, thus, the death of retinal ganglion cells in primary open angle glaucoma.

  3. Failure of Polyethelene Insert Locking Mechanism after a Posterior Stabilised Total Knee Arthroplasty- A Case Report

    PubMed Central

    Reddy, AY Gurava; Rajan, D Soundar; Chiranjeevi, T; Karthik, C; Kiran, E Krishna

    2016-01-01

    Introduction: Disengagement of polyethylene insert used in total knee arthroplasty is a rare but serious complication. Still rarer is disengagement because of failure of tibial insert locking mechanism. We report a previously unpublished complication of polyethylene insert locking mechanism failure in a 10-months-old posterior stabilized total knee arthroplasty in a 70-year-old woman with osteoarthritis for whom Attune (Depuy) knee implant was used. Case Presentation: A 70-year-old female underwent (Attune, Depuy) primary bilateral posterior stabilised total knee arthroplasty in a private hospital. The patient did not have any complaints and had had been functioning well post her arthroplasty. After five months of surgery she had a fall and sustained injury over right hip which was treated with Cemented Bipolar Hemiarthroplasty. Ten months after index surgery, she sustained trivial fall and presented to the same hospital with knee pain and swelling, where the right knee prosthesis was found to be dislocated. An attempted closed reduction under anaesthesia failed, after which she was referred to our centre with an unstable, painful, swollen right knee in a long knee brace. The physical examination at the time of admission showed posterior sag of the tibia, fullness in the postero-lateral corner, quadriceps muscle atrophy without any neurovascular deficit oflower leg. Postero-lateral dislocation was confirmed with radiographs. Surgical error as a possible causative factor was excluded because patient had been functioning well after surgery. Her comorbidities included hypertension and hyponatremia. ESR and CRP were within normal limits. An open reduction surgery was planned. On exposure, polyethylene was found in the postero-lateral corner of the knee. We were not sure that revising the polyethylene alone would suffice as the poly and locking mechanism was of a relatively new design and hence it was decided to proceed with revision of the components. Revision was done

  4. Ultrasound Elasticity Imaging for Determining the Mechanical Properties of Human Posterior Tibial Tendon: A Cadaveric Study

    PubMed Central

    Yuan, Justin S.; Heden, Gregory J.; Szivek, John A.; Taljanovic, Mihra S.; Latt, L. Daniel; Witte, Russell S.

    2016-01-01

    Posterior tibial tendon dysfunction (PTTD) is a common degenerative condition leading to a severe impairment of gait. There is currently no effective method to determine whether a patient with advanced PTTD would benefit from several months of bracing and physical therapy or ultimately require surgery. Tendon degeneration is closely associated with irreversible degradation of its collagen structure, leading to changes to its mechanical properties. If these properties could be monitored in vivo, they could be used to quantify the severity of tendonosis and help determine the appropriate treatment. The goal of this cadaveric study was, therefore, to develop and validate ultrasound elasticity imaging (UEI) as a potentially noninvasive technique for quantifying tendon mechanical properties. Five human cadaver feet were mounted in a materials testing system (MTS), while the posterior tibial tendon (PTT) was attached to a force actuator. A portable ultrasound scanner collected 2-D data during loading cycles. Young’s modulus was calculated from the strain, loading force, and cross-sectional area of the PTT. Average Young’s modulus for the five tendons was (0.45 ± 0.16 GPa) using UEI, which was consistent with simultaneous measurements made by the MTS across the whole tendon (0.52 ± 0.18 GPa). We also calculated the scaling factor (0.12 ± 0.01) between the load on the PTT and the inversion force at the forefoot, a measurable quantity in vivo. This study suggests that UEI could be a reliable in vivo technique for estimating the mechanical properties of the PTT, and as a clinical tool, help guide treatment decisions for advanced PTTD and other tendinopathies. PMID:25532163

  5. Prevention of Evisceration or Enucleation in Endogenous Bacterial Panophthalmitis with No Light Perception and Scleral Abscess

    PubMed Central

    Chen, Kuan-Jen; Chen, Yen-Po; Chao, An-Ning; Wang, Nan-Kai; Wu, Wei-Chi; Lai, Chi-Chun; Chen, Tun-Lu

    2017-01-01

    Panophthalmitis is the most extensive ocular involvement in endophthalmitis with inflammation in periocular tissues. Severe inflammation of the anterior and posterior segments is frequently accompanied by corneal opacity, scleral abscess, and perforation or rupture. Enucleation or evisceration was the only remaining viable treatment option when all options to salvage the eye had been exhausted. The purpose of this retrospective study is to examine the outcomes of patients with endogenous bacterial panophthalmitis, no light perception and scleral abscess who were treated with multiple intravitreal and periocular injections of antibiotics and dexamethasone. Evaluation included spreading of infection to contiguous or remote sites, following evisceration or enucleation, and sympathetic ophthalmia. Eighteen patients were diagnosed with EBP, with liver abscesses in eight patients, retroperitoneal infection in four, pneumonia in two, infective endocarditis in one, cellulitis in one, drug abuse in one, and mycotic pseudoaneurysm in one. Culture results were positive for Klebsiella pneumoniae in 12 patients, Streptococcus spp. in three, Pseudomonas aeruginosa in one, Escherichia coli in one, and Staphylococcus aureus in one. The average number of periocular injections was 2.2, and the average number of intravitreal injections was 5.8. No eye required evisceration or enucleation and developed the spreading of infection to contiguous or remote sites during the follow-up. No sympathetic ophthalmia was observed in the fellow eye of all patients. Prevention of evisceration or enucleation in patients with EBP, NLP and scleral abscess can be achieved by multiple intravitreal and periocular injections of antibiotics and dexamethasone. PMID:28056067

  6. Genome-Wide Scleral Micro- and Messenger-RNA Regulation During Myopia Development in the Mouse

    PubMed Central

    Metlapally, Ravikanth; Park, Han Na; Chakraborty, Ranjay; Wang, Kevin K.; Tan, Christopher C.; Light, Jacob G.; Pardue, Machelle T.; Wildsoet, Christine F.

    2016-01-01

    Purpose MicroRNA (miRNAs) have been previously implicated in scleral remodeling in normal eye growth. They have the potential to be therapeutic targets for prevention/retardation of exaggerated eye growth in myopia by modulating scleral matrix remodeling. To explore this potential, genome-wide miRNA and messenger RNA (mRNA) scleral profiles in myopic and control eyes from mice were studied. Methods C57BL/6J mice (n = 7; P28) reared under a 12L:12D cycle were form-deprived (FD) unilaterally for 2 weeks. Refractive error and axial length changes were measured using photorefraction and 1310-nm spectral-domain optical coherence tomography, respectively. Scleral RNA samples from FD and fellow control eyes were processed for microarray assay. Statistical analyses were performed using National Institute of Aging array analysis tool; group comparisons were made using ANOVA, and gene ontologies were identified using software available on the Web. Findings were confirmed using quantitative PCR in a separate group of mice (n = 7). Results Form-deprived eyes showed myopic shifts in refractive error (−2.02 ± 0.47 D; P < 0.01). Comparison of the scleral RNA profiles of test eyes with those of control eyes revealed 54 differentially expressed miRNAs and 261 mRNAs fold-change >1.25 (maximum fold change = 1.63 and 2.7 for miRNAs and mRNAs, respectively) (P < 0.05; minimum, P = 0.0001). Significant ontologies showing gene over-representation (P < 0.05) included intermediate filament organization, scaffold protein binding, detection of stimuli, calcium ion, G protein, and phototransduction. Significant differential expression of Let-7a and miR-16-2, and Smok4a, Prph2, and Gnat1 were confirmed. Conclusions Scleral mi- and mRNAs showed differential expression linked to myopia, supporting the involvement of miRNAs in eye growth regulation. The observed general trend of relatively small fold-changes suggests a tightly controlled, regulatory mechanism for scleral gene expression. PMID

  7. Effect of passive self-ligating bracket placement on the posterior teeth on reduction of frictional force in sliding mechanics

    PubMed Central

    Kim, Kyu-Ry

    2016-01-01

    Objective The purpose of this study was to investigate the static (SFF) and kinetic frictional forces (KFF) in sliding mechanics of hybrid bracket systems that involve placing a conventional bracket (CB) or active self-ligating bracket (ASLB) on the maxillary anterior teeth (MXAT) and a passive SLB (PSLB) on the maxillary posterior teeth (MXPT). Methods The samples consisted of two thoroughbred types (group 1, anterior-CB + posterior-CB; group 2, anterior-ASLB + posterior-ASLB) and four hybrid types (group 3, anterior-CB + posterior-PSLB-type 1; group 4, anterior-CB + posterior-PSLB-type 2; group 5, anterior-ASLB + posterior-PSLB-type 1; group 6, anterior-ASLB + posterior-PSLB-type 2) (n = 13 per group). After maxillary dentition alignment and maxillary first premolars removal in the stereolithographically-made typodont system, a 0.019 × 0.025-inch stainless steel wire was drawn through the right quadrant of the maxillary arch at 0.5 mm/min for 5 min. The SFF and KFF were measured with a mechanical testing machine and statistical analyses were performed. Results Four different categories of SFF and KFF were observed among all groups (all p < 0.001). Group 1 demonstrated the highest SFF and KFF; groups 4 and 3 were second and third highest, respectively. The fourth category included groups 2, 5, and 6. Placing PSLBs on the MXPT resulted in significant SFF and KFF reductions in cases with CBs on the MXAT, but not in cases with ASLBs on the MXAT. Conclusions These data might aid in the development of a hybrid bracket system that enables low-friction sliding of an archwire through the MXPT. PMID:27019821

  8. [Hemiplegia in posterior cerebral artery infarctions: analysis of various responsible mechanisms].

    PubMed

    Ortiz, N; Barraquer Bordas, L; Dourado, M; Rey, A; Avila, A

    1993-01-01

    When cerebral infarction determines hemiplegia or hemiparesia which accompany a hemilateral sensitive deficit and hemianopsia and even neuropsychologic symptoms (aphasic alterations in the case of injury to the left hemisphere, heminegligence and anosognosy in the case of injury to the right hemisphere) the involvement of a sylvian artery syndrome is usually considered. Nonetheless, recent contributions have reported that such symptoms may appear in infarctions of the territory of the posterior cerebral artery. Two clinical-radiologic observations in this line are presented. Nuclear magnetic resonance demonstrated injury to the posterior arm of the internal capsule in one case and in the other the lesion developed over three times, in the latter of which injury to the cerebral peduncle was produced causing hemiparesia. The authors emphasize that hemiplegia or hemiparesia in some infarctions of the posterior cerebral artery may be due to 1) mesencephalic infarction in the posterior plane of the retromamillar Foix and Hillemand pediculum (or G. Lazorthes interpedunculum), 2) infarction or "ischemic penumbra" in the internal capsule by involvement of any of the perforating branches of the posterior cerebrum irrigating the thalamus, except for the medial posterior choroid artery or even of the Foix and Hillemand thalamus-tuberian pediculum (or Lazorthes inferior and anterior) which principally initiates at the posterior communicating branch with a fragment of the posterior branch of the internal capsule perhaps not always being under its control. In this case, the thrombus occupying the posterior cerebrum may extend to the cited communicating branch or a hemodynamic deficit may be produced in the territory of the same.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Endoilluminator-assisted scleral buckling: Our results

    PubMed Central

    Gogia, Varun; Venkatesh, Pradeep; Gupta, Shikha; Kakkar, Ashish; Garg, Satpal

    2014-01-01

    Aims: The aim was to evaluate the long-term surgical outcomes of endoillumination assisted scleral buckling (EASB) in primary rhegmatogenous retinal detachment (RRD). Methods: Twenty-five eyes of 25 patients with primary RRD and proliferative vitreoretinopathy ≤C2 where any preoperative break could not be localised, were included. All patients underwent 25 gauge endoilluminator assisted rhegma localisation. Successful break determination was followed by cryopexy and standard scleral buckling under surgical microscope. Anatomical and functional outcomes were evaluated at the end of 2 years. Results: At least one intraoperative break could be localized in 23 of 25 (92%) eyes. Median age of these patients was 46 years (range: 17-72). Thirteen eyes (56.52%) were phakic, 8 (34.78%) were pseudophakic and 2 (8.6%) were aphakic. Anatomical success (attachment of retina) was achieved in 22 (95.63%) of 23 eyes with EASB. All eyes remained attached at the end of 2 years. Significant improvement in mean visual acuity (VA) was achieved at the end of follow-up (1.09 ± 0.46 log of the minimum angle of resolution [logMAR]) compared with preoperative VA (1.77 ± 0.28 logMAR) (P < 0.001). Conclusion: EASB can be considered an effective alternative to vitreoretinal surgery in simple retinal detachment cases with the added advantage of enhanced microscopic magnification and wide field illumination. PMID:25230970

  10. Bleb Revision using Reversed Scleral Flap and Pedical Conjunctival Graft.

    PubMed

    Sharma, Sourabh; Patel, Dhaval; Sharma, Reetika; Dada, Tanuj

    2012-01-01

    Bleb revision for hypotony maculopathy following trabeculectomy is an effective technique for raising intraocular pressure and limiting visual loss. The presence for scleral fistula causing over-filtration obviates the need for reinforcing materials, such as donor sclera or pericardium to cover the defect. However, if the surrounding scleral tissue is healthy, a partial thickness scleral flap can be upturned and sutured over the fistula. Moreover, a vascularized pedical conjunctival graft can also be used in cases where there is a large conjunctival defect.

  11. Non-drainage scleral buckling with solid silicone elements

    PubMed Central

    Rishi, Pukhraj; Rishi, Ekta; Gupta, Aditi; Mathew, Cheriyan Shane; Shah, Bhavesh J.

    2014-01-01

    Background: With the increasing number of cataract surgeries, incidence of posterior segment complications including rhegmatogenous retinal detachment (RRD) is likely to rise. Scleral buckling (SB) surgery is an effective and less expensive option. The primary advantage of non-drainage procedure is avoidance of possible complications associated with trans-choroidal drainage. The aim of present study is to describe the clinical profile of subjects undergoing non-drainage SB surgery with solid silicone elements for RRD and analyze their treatment outcomes. Materials and Methods: This was a retrospective, non-randomized, interventional study at a tertiary care center. Three hundred and six eyes of 298 patients undergoing non-drainage SB surgery with solid silicone elements from year 2000 to 2006 were included. Inclusion criteria were primary RRD, peripheral depressible retinal break, media clarity affording peripheral retinal view and proliferative vitreo-retinopathy (PVR) up to grade C2. Uni- and multivariate analyses was done to analyze factors affecting anatomical and visual outcomes. Statistical analysis was performed using SPSS Version 10. Results: Mean follow-up was 303 ± 393.33 days. Primary anatomical success was obtained in 279 (91.2%) eyes; primary functional success in 286 (93.5%) eyes. PVR (grade B or C), intraocular pressure <10 mm Hg and the inability to find a retinal break were significantly associated with final anatomical failure. Baseline vision ≤3/60 was significantly associated with poor visual recovery. Conclusions: SB surgery is reasonably safe and highly efficacious. Solid silicone elements are effective in non-drainage SB surgery. However, case selection is important. PMID:25136227

  12. odd-skipped genes and lines organize the notum anterior-posterior axis using autonomous and non-autonomous mechanisms.

    PubMed

    Del Signore, Steven J; Hayashi, Teru; Hatini, Victor

    2012-07-01

    The growth and patterning of Drosophila wing and notum primordia depend on their subdivision into progressively smaller domains by secreted signals that emanate from localized sources termed organizers. While the mechanisms that organize the wing primordium have been studied extensively, those that organize the notum are incompletely understood. The genes odd-skipped (odd), drumstick (drm), sob, and bowl comprise the odd-skipped family of C(2)H(2) zinc finger genes, which has been implicated in notum growth and patterning. Here we show that drm, Bowl, and eyegone (eyg), a gene required for notum patterning, accumulate in nested domains in the anterior notum. Ectopic drm organized the nested expression of these anterior notum genes and downregulated the expression of posterior notum genes. The cell-autonomous induction of Bowl and Eyg required bowl, while the non-autonomous effects were independent of bowl. The homeodomain protein Bar is expressed along the anterior border of the notum adjacent to cells expressing the Notch (N) ligand Delta (Dl). bowl was required to promote Bar and repress Dl expression to pattern the anterior notum in a cell-autonomous manner, while lines acted antagonistically to bowl posterior to the Bowl domain. Our data suggest that the odd-skipped genes act at the anterior notum border to organize the notum anterior-posterior (AP) axis using both autonomous and non-autonomous mechanisms.

  13. Damage threshold in adult rabbit eyes after scleral cross-linking by riboflavin/blue light application.

    PubMed

    Iseli, Hans Peter; Körber, Nicole; Karl, Anett; Koch, Christian; Schuldt, Carsten; Penk, Anja; Liu, Qing; Huster, Daniel; Käs, Josef; Reichenbach, Andreas; Wiedemann, Peter; Francke, Mike

    2015-10-01

    Several scleral cross-linking (SXL) methods were suggested to increase the biomechanical stiffness of scleral tissue and therefore, to inhibit axial eye elongation in progressive myopia. In addition to scleral cross-linking and biomechanical effects caused by riboflavin and light irradiation such a treatment might induce tissue damage, dependent on the light intensity used. Therefore, we characterized the damage threshold and mechanical stiffening effect in rabbit eyes after application of riboflavin combined with various blue light intensities. Adult pigmented and albino rabbits were treated with riboflavin (0.5 %) and varying blue light (450 ± 50 nm) dosages from 18 to 780 J/cm(2) (15 to 650 mW/cm(2) for 20 min). Scleral, choroidal and retinal tissue alterations were detected by means of light microscopy, electron microscopy and immunohistochemistry. Biomechanical changes were measured by shear rheology. Blue light dosages of 480 J/cm(2) (400 mW/cm(2)) and beyond induced pathological changes in ocular tissues; the damage threshold was defined by the light intensities which induced cellular degeneration and/or massive collagen structure changes. At such high dosages, we observed alterations of the collagen structure in scleral tissue, as well as pigment aggregation, internal hemorrhages, and collapsed blood vessels. Additionally, photoreceptor degenerations associated with microglia activation and macroglia cell reactivity in the retina were detected. These pathological alterations were locally restricted to the treated areas. Pigmentation of rabbit eyes did not change the damage threshold after a treatment with riboflavin and blue light but seems to influence the vulnerability for blue light irradiations. Increased biomechanical stiffness of scleral tissue could be achieved with blue light intensities below the characterized damage threshold. We conclude that riboflavin and blue light application increased the biomechanical stiffness of scleral tissue at

  14. Gene expression suggests double-segmental and single-segmental patterning mechanisms during posterior segment addition in the beetle Tribolium castaneum.

    PubMed

    Janssen, Ralf

    2014-01-01

    In the model arthropod Drosophila, all segments are patterned simultaneously in the blastoderm. In most other arthropods, however, posterior segments are added sequentially from a posterior segment addition zone. Posterior addition of single segments likely represents the ancestral mode of arthropod segmentation, although in Drosophila, segments are patterned in pairs by the pair-rule genes. It has been shown that in the new model insect, the beetle Tribolium, a segmentation clock operates that apparently patterns all segments in pairs as well. Here, I report on the expression of the segment polarity gene H15/midline in Tribolium. In the anterior embryo, segmental stripes of H15 appear in pairs, but in the posterior of the embryo stripes appear in a single-segmental periodicity. This implies that either two completely different segmentation-mechanisms may act in the germ band of Tribolium, that the segmentation clock changes its periodicity during development, or that the speed in which posterior segments are patterned changes. In any case, the data suggest the presence of another (or modified), yet undiscovered, mechanism of posterior segment addition in one of the best-understood arthropod models. The finding of a hitherto unrecognized segmentation mechanism in Tribolium may have major implications for the understanding of the origin of segmentation mechanisms, including the origin of pair rule patterning. It also calls for (re)-investigation of posterior segment addition in Tribolium and other previously studied arthropod models.

  15. In vitro scleral lutein distribution by cyclodextrin containing nanoemulsions.

    PubMed

    Liu, Chi-Hsien; Lai, Kuan-Yu; Wu, Wei-Chi; Chen, Yu-Jui; Lee, Wei-Shiou; Hsu, Ching-Yun

    2015-01-01

    Lutein is a macular pigment that contributes to maintaining eye health. The development of lutein-laden nanocarriers for ocular delivery would have the advantages of user friendliness and cost-effectiveness. Nano-scaled vehicles such as cyclodextrin (CD) and nanoemulsion could overcome the barriers caused by the scleral structure. This study focused on the development of hybrid nanocarriers containing nanoemulsion and CD for scleral lutein accumulation. In the presence of the nanoemulsion, CD forms such as βCD and hydroxyethyl (HE) βCD increased the partition of lutein into the porcine sclera. A combination of nanoemulsion and 2% HEβCD enhanced lutein accumulation to 119±6 µg g(-1) h(-1), which was 9.2-fold higher than that with lutein suspension alone. We explored the dose effect of CD in nanoemulsion on scleral lutein and found that the scleral accumulation of lutein was enhanced by increasing the CD content. The novel nanoemulsion had 95% drug-loading efficiency and low cytotoxicity in retinal cells. The CD-modified nanoemulsion not only improved the stability and entrapment efficacy of lutein in the aqueous system but also enhanced scleral lutein accumulation. An increase in the partition coefficient of lutein in porcine sclera when using the CD-modified nanoemulsion was also confirmed.

  16. Supplemental gas tamponade after conventional scleral buckling surgery--a simple alternative to surgical revision.

    PubMed Central

    Worsley, D R; Grey, R H

    1991-01-01

    Supplemental intravitreal gas injection was used in the early postoperative period in an attempt to achieve long term retinal reattachment in 11 cases of failed scleral buckling surgery. Success was dependent on the presence of a correctly placed scleral buckle underlying all breaks. Surgical revision was thereby avoided in these patients. However, when the scleral buckle was inadequate the technique failed. PMID:1911655

  17. Effect of Mechanical Loads and Surface Roughness on Wear of Silorane and Methacrylate-Based Posterior Composites

    PubMed Central

    Tabatabaei, Masomeh Hasani; Arami, Sakineh

    2016-01-01

    Objectives: Dental composite wear in posterior restorations is a concern and is affected by different factors. This study was conducted to evaluate the effect of polishing and mechanical loads on wear of silorane-based and methyl methacrylate-based composites resins. Materials and Methods: Of each dental composite (Filtek P90 and Filtek P60), 40 samples were fabricated in a polyethylene mold (4mm diameter, 10mm height). According to the finishing and/or polishing protocols (180-grit or 2500-grit silicon carbide papers), the samples of each composite were divided into two groups. Surface roughness (R ә ) was measured and recorded using a contact profilometer. The weight of each sample was also measured in grams. The wear test was performed in a pin-on-disc device under two different loads (70N, 150N). Afterwards, samples were subjected to profilometry and their weight was measured again. Data were analyzed using t-test and univariate ANOVA. P <0.05 was considered statistically significant. Results: Higher mechanical load resulted in greater weight loss (P<0.001). Samples polished with 2500-grit papers showed significantly lower Ra changes compared to those polished with 180-grit papers (P<0.001). Filtek P90 had greater weight loss than Filtek P60 except in one condition (180-grit, 70N). Conclusions: Results showed that wear of posterior composite restorations depends on mechanical load, type of composite resin and surface properties. PMID:28243302

  18. High speed small gauge anterior vitrectomy cutter for scleral fixated intraocular lens implantation

    PubMed Central

    Liang, Yuan Bo; Fong, Yoly Y.Y.; Cheng, Lulu L.; Young, Alvin L.

    2017-01-01

    AIM To report the outcomes of anterior vitrectomy using high speed cutter for scleral fixated intraocular lens (SFIOL) implantation in patients with posterior capsular rupture. METHODS Medical records of 51 patients with posterior capsular rupture who received high speed cutter anterior vitrectomy via limbal incision with SFIOL implantation from June 2011 to December 2013 were reviewed retrospectively for visual outcomes and complications. RESULTS Totally 51 eyes of 51 patients were identified (23 males and 28 females). Mean age at surgery was 67.2±15y (range 27-91y), with mean follow-up of 23±8.2mo (range 12-40mo). The 49 (96.1%) eyes had improvement or unchanged of final postoperative visual acuity. The most common complication was vitreous haemorrhage (5.9%) and transient rise in intraocular pressure (5.9%) which all spontaneously resolved CONCLUSION High speed cutter anterior vitrectomy via limbal incision is a safe and effective method for those with posterior capsular rupture for SFIOL implantation. PMID:28149781

  19. Differential mechanisms for insulin-induced relaxations in mouse posterior tibial arteries and main mesenteric arteries.

    PubMed

    Qu, Dan; Liu, Jian; Lau, Chi Wai; Huang, Yu

    2014-12-01

    The characteristics of endothelium-dependent relaxations in response to insulin and acetylcholine (ACh) in the mouse posterior tibial artery (PTA) were studied on wire myograph, and compared to those in the mouse main mesenteric artery (MMA). Insulin-induced relaxation in PTA was reversed by PI3K and Akt inhibitors, LY294002 and triciribine, but not by nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME) or guanylate cyclase inhibitor, ODQ. The relaxation in PTA was also inhibited by apamin (small-conductance Ca(2+)-activated K(+) channel blocker) plus charybdotoxin (intermediate-conductance Ca(2+)-activated K(+) channel blocker), elevated KCl or ouabain (Na(+)-K(+) ATPase inhibitor) plus BaCl(2) [inwardly rectifying K(+) (K(IR)) channel inhibitor]; whereas L-NAME but not triciribine inhibited ACh-induced relaxation in PTA. On the other hand, nitric oxide and endothelium-derived hyperpolarizing factor albeit to a less extent mediated both insulin- and ACh-induced relaxations in MMA. The present study is for the first time dissecting out the components of endothelium-dependent relaxation in mouse PTA and suggesting differential responses to different agonists in distinctive blood vessels.

  20. Evaluation of tissue adhesives in closure of scleral tunnel incisions.

    PubMed

    Kim, J C; Bassage, S D; Kempski, M H; del Cerro, M; Park, S B; Aquavella, J V

    1995-05-01

    Using a biomechanical wound strength model, we compared the efficacy of cyanoacrylate and fibrin glues used to close scleral tunnel incisions. Scleral tunnel incisions were made in four groups of rabbits: (1) traditional self-sealing incision, (2) modified non-self-sealing incision, (3) method 2, closed with cyanoacrylate glue, or (4) method 2, closed with fibrin glue. Overall, Groups 1 and 4 showed the least clinical reaction, the slightest decrease in intraocular pressure (which recovered to baseline by day 7), and the most significant recovery of postoperative astigmatism. Initially, the bursting pressure in Groups 1 and 3 was statistically the highest (P < .005). By day 3, wound strengths in Groups 1 and 4 were comparable. Bursting pressure decreased in Groups 2 and 3 by day 7. Our results indicate that clinical responses, intraocular pressure, induced astigmatism, and ultimately wound strength were comparable in fibrin-glue-closed scleral pocket and sutureless self-sealing cataract incisions. Although cyanoacrylate glue cures immediately and initially demonstrates a strong adhesive quality, it causes a severe inflammatory response that inhibits subsequent collagen remodeling. Fibrin tissue adhesives may have an application as adjunctive means of closing scleral tunnel incisions.

  1. [Changes in axial length after scleral buckling surgery].

    PubMed

    Hayashi, H; Hayashi, K; Nakao, F; Hayashi, F

    1996-04-01

    The eye lengthens after scleral buckling surgery for retinal detachment. We investigated the changes in axial length and refraction after scleral buckling. A total of 89 eyes from 88 patients which were all scheduled to undergo scleral buckling were included in this study. The eyes were classified into four groups based on the type of buckling procedures:1 local buckling, 2 encircling, 3 encircling with vitrectomy, and 4 encircling with local buckling. We examined the axial length of these eyes using ultrasonography, preoperatively and at 1, 3, and 6 months postoperatively. The refractive changes were also examined. Depending on the type of scleral buckling procedure employed, the eyes in Groups 2, 3, and 4 clearly lengthened, but those of Group 1 did not. The amount of axial lengthening in Groups 2, 3, and 4 was significantly greater than in Group 1 at 3 and 6 months after surgery. In the spherical equivalent, a myopic shift occurred in the eyes in Groups 2, 3, and 4, and this shift was significantly greater than in Group 1 In addition, the correlation between the extent of axial lengthening and myopic shift was significant. In conclusion, the axial length increases with a myopic shift due to encircling, whereas local buckling changed the axial length only slightly.

  2. Scleral fibroblast response to experimental glaucoma in mice

    PubMed Central

    Tezel, Gülgün; Cone-Kimball, Elizabeth; Steinhart, Matthew R.; Jefferys, Joan; Pease, Mary E.; Quigley, Harry A.

    2016-01-01

    Purpose To study the detailed cellular and molecular changes in the mouse sclera subjected to experimental glaucoma. Methods Three strains of mice underwent experimental bead-injection glaucoma and were euthanized at 3 days and 1, 3, and 6 weeks. Scleral protein expression was analyzed with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) using 16O/18O labeling for quantification in 1- and 6-week tissues. Sclera protein samples were also analyzed with immunoblotting with specific antibodies to selected proteins. The proportion of proliferating scleral fibroblasts was quantified with Ki67 and 4’,6-diamidino-2-phenylindole (DAPI) labeling, and selected proteins were studied with immunohistochemistry. Results Proteomic analysis showed increases in molecules involved in integrin-linked kinase signaling and actin cytoskeleton signaling pathways at 1 and 6 weeks after experimental glaucoma. The peripapillary scleral region had more fibroblasts than equatorial sclera (p=0.001, n=217, multivariable regression models). There was a sixfold increase in proliferating fibroblasts in the experimental glaucoma sclera at 1 week and a threefold rise at 3 and 6 weeks (p=0.0005, univariate regression). Immunoblots confirmed increases for myosin, spectrin, and actinin at 1 week after glaucoma. Thrombospondin-1 (TSP-1), HINT1, vimentin, actinin, and α-smooth muscle actin were increased according to immunohistochemistry. Conclusions Scleral fibroblasts in experimental mouse glaucoma show increases in actin cytoskeleton and integrin-related signaling, increases in cell division, and features compatible with myofibroblast transition. PMID:26900327

  3. Scleral buckling surgery for rhegmatogenous retinal detachment with subretinal proliferation

    PubMed Central

    Ghasemi Falavarjani, K; Alemzadeh, S A; Modarres, M; Parvaresh, M M; Hashemi, M; Naseripour, M; Nazari Khanamiri, H; Askari, S

    2015-01-01

    Purpose To evaluate the outcome of scleral buckling surgery in patients with rhegmatogenous retinal detachment (RRD) with subretinal proliferation. Methods In this retrospective study, a chart review of all patients with RRD associated with subretinal proliferation who were primarily treated with scleral buckling procedure, from April 2007 to April 2014, was undertaken. Main outcome measures were anatomical retinal reattachment and visual acuity. Results Forty-four eyes of 43 patients including 24 males and 19 females with a mean age of 26.5±13.1 years were evaluated. Immediately after the surgery, retina was reattached in all eyes. However, five eyes (11.3%) needed additional surgery for retinal redetachment. Single surgery anatomical success rate was 88.7%. Four eyes (9.1%), needed pars plana vitrectomy for the treatment of redetachment associated with proliferative vitreoretinopathy and scleral buckle revision surgery was successfully performed in the other eye. Best corrected visual acuity improved from 1.5±0.9 logMAR before surgery to 1.1±0.7 logMAR after surgery (P<0.001). An improvement in BCVA of >2 lines was found in 23 eyes (52.2%) and worsening of best corrected visual acuity of >2 lines was observed in 2 eyes (4.5%). Conclusions Scleral buckling surgery is highly successful in eyes with RRD associated with subretinal proliferation. PMID:25613841

  4. [Distribution and compensation mechanism of aberrations between anterior and posterior surface of the cornea in myopia and myopic astigmatism eyes].

    PubMed

    Li, X J; Wang, Y; Wu, Y N; Wu, W J; Yu, C J; Xu, L L

    2016-11-11

    Objective: To study the compensation mechanism of aberrations between anterior and posterior corneal surface, and to investigate the correlations between corneal aberrations and K values, intraocular pressure and central corneal thickness. Methods: One hundred and sixty-one subjects (300 eyes) with myopia and myopic astigmatism were recruited randomly. Corneal aberrations (anterior, posterior and total) in three different optical zones (2 mm, 4 mm, and 6 mm) centered on the corneal vertex were assessed with a corneal topographer (Sirius). We also calculated compensation factors (CFs) as a measure of the relative efficiency of the aberration compensation mechanism. Astigmatism was divided into corneal astigmatism and non-corneal astigmatism. Mann-Whitney U test was utilized for the comparison of different aberrations and CFs between the two astigmatism groups. Spearman correlation was applied to analyze the correlations between corneal aberrations and K values, intraocular pressure and central corneal thickness. Results: As the order of the aberrations elevated from the second to the seventh, the RMS values decreased significantly. The larger the optical zone, the greater the values of aberrations and the lower the percentage of the compensation mechanism among all the Zernike terms. At the same time, as the order of the aberrations increased, the predominance of the compensation mechanism was increasingly obvious. Slight compensation of spherical aberration (Z4(0)) was observed in the peripheral. In the center of the analyzing zones (2 mm), compensation mechanism represented in coma (Z3(±1)), and it disappeared in the peripheral. We detected slight compensation of the corneal astigmatism (Z2(±2)) in the surrounding zone, although the compensation factors were closed to zero in diverse optical zones. Superposition was found in trefoil (Z3(±3)) straightly. Nevertheless, a tendency towards compensation was discovered with the enlargement of the optical zones. And

  5. Mechanism of posterior semicircular canal stimulation in patients with benign paroxysmal positional vertigo.

    PubMed

    Honrubia, V; House, M

    2001-01-01

    A quantitative study of the stimuli and vestibulo-ocular response associated with benign paroxysmal positional vertigo (BPPV) was made to test and further develop the canalithiasis theory of BPPV. The angular velocities of the head in the planes of the semicircular canals during the Dix-Hallpike test were measured in four healthy subjects using electromagnetic sensors to record the position of the head in a six degrees of freedom paradigm. Next, the nystagmus reactions in seven patients diagnosed with idiopathic BPPV were recorded with video-oculography. The characteristics of the vestibulo-ocular reflex (VOR) response were analyzed using three-dimensional vector techniques. The angular velocity of the head was primarily, but not exclusively, in the plane of the posterior semicircular canal (PSC) in question. Both the anterior and horizontal canals were also stimulated by a lesser degree. The duration of the motion stimulus in the PSC was < 1.3 s with peak angular velocities of 150 deg/s. The eye response in BPPV patients began 4 s after the test and had a duration of 15-20 s. Peak slow-component eye velocities of about 42 deg/s were reached 3-5 s after onset of nystagmus. The motion of the eye, as predicted by the cupulolithiasis theory, is disconjugated and has torsional, vertical, and horizontal components. In the eye ipsilateral to the tested ear it is primarily torsional (0.80, 0.54, 0.16) and in the contralateral eye it is mainly vertical (0.57, 0.73, 0.08). These results suggest that particles, initially resting on the floor of the cupula dome in the PSC, are perturbed by the Dix-Hallpike test and disperse freely into the endolymph where they are propelled by gravity into the canal lumen. This creates abnormal pressure on the cupula and the specific VOR activation of the ipsilateral superior oblique and the contralateral inferior rectus muscles, whose force vectors are indistinguishable from the measured eye motion vectors. The estimated pressure exerted on

  6. Combined Scleral Flap with Donor Scleral Patch Graft for Anterior Tube Placement in Glaucoma Drainage Device Surgery

    PubMed Central

    Yu, Jea H.; Nguyen, Chuck; Gallemore, Esmeralda

    2016-01-01

    Purpose. To report a new technique for anterior placement of tubes for glaucoma drainage devices to reduce the risk of tube erosions. Methods. Retrospective review of select cases of Ahmed Valve surgery combined with the novel method of a limbal-based scleral flap covered by a scleral patch graft to cover the tube at the entrance through the limbus. Intraoperative and postoperative illustrations are shown to highlight the method of tube placement. Results. In this retrospective case series, 3 patients are presented illustrating the technique. Two had neovascular glaucoma and one had primary open-angle glaucoma (POAG). On average, intraocular pressure was reduced from 39 ± 14 mmHg to 15 ± 2 mmHg and the number of glaucoma medications was reduced from 4 ± 1 to 0. Preoperative and most recent visual acuities were hand-motion (HM) and HM, 20/60 and 20/50, and 20/70 and 20/30, respectively. Conclusion. The combination of a limbal-based scleral flap with scleral patch graft to cover the tube with glaucoma drainage devices may be an effective means to reduce erosion and protect against endophthalmitis. PMID:27747118

  7. One "8"-shaped scleral suture to treat rhegmatogenous retinal detachment: a refined procedure of minimal scleral buckling.

    PubMed

    Min, H Y; Chen, D; Chen, Y; Dong, F T

    2014-08-28

    The aim of this study was to investigate the outcomes of one "8"-shaped scleral suture of minimal scleral buckling (MSB) surgery without sub-retinal drainage for rhegmatogenous retinal detachment (RRD) treatment. Thirty patients (30 eyes) with RRD were recruited. Thirty eyes with RRD were repaired by one "8"-shaped scleral suture of minimal buckling without subretinal drainage by one surgeon. The refined MSB procedure is described. Reattachment time and best-corrected visual acuity (BCVA) were observed. The age of the 30 patients ranged from 17 to 65 years (mean, 43.1 ± 8.6 years). The retinas of 19 eyes (63.3%) reattached within 12 h of the operations, and those of 11 eyes (67%) reattached within 72 h. The average time of follow-up was 10.4 ± 2.8 months. BCVAs were increased in 27 eyes (90%), whereas those of 3 eyes did not change. The mean preoperative BCVA was 0.738 ± 0.368 log minimal angle of resolution (MAR), and mean postoperative BCVA was 0.422 ± 0.278 logMAR, and the difference was statistically significant (P < 0.05). The sponge for buckling in only one eye exposed from the conjunctiva was taken out, and the retina remained attached. In conclusion, an "8"-shaped scleral suture of MSB without sub-retinal drainage is an efficient procedure to treat selected RRD cases.

  8. Anterior eye tissue morphology: Scleral and conjunctival thickness in children and young adults

    PubMed Central

    Read, Scott A.; Alonso-Caneiro, David; Vincent, Stephen J.; Bremner, Alexander; Fothergill, Annabel; Ismail, Brittney; McGraw, Rebecca; Quirk, Charlotte J.; Wrigley, Elspeth

    2016-01-01

    The sclera and conjunctiva form part of the eye’s tough, protective outer coat, and play important roles in the eye’s mechanical protection and immune defence, as well as in determining the size and shape of the eye globe. Advances in ocular imaging technology now allow these tissues in the anterior eye to be imaged non-invasively and with high resolution, however there is a paucity of data examining the dimensions of these tissues in paediatric populations. In this study, we have used optical coherence tomography (OCT) imaging to examine the normal in vivo thickness profile of the anterior sclera and overlying conjunctiva in 111 healthy young participants, including a large proportion of paediatric subjects. We demonstrate that the thickness of the anterior sclera varies significantly with measurement location and meridian. Tissue thickness also varied significantly with age, with younger subjects exhibiting significantly thinner scleras and significantly greater conjunctival thickness. Males were also found to exhibit significantly greater scleral thickness. Refractive error however was not significantly associated with either scleral or conjunctival thickness in this population. These findings provide new data describing the normative dimensions of anterior eye tissues in children and the factors that can influence these dimensions in young populations. PMID:27646956

  9. Inadvertent sclerostomy with encysted bleb following trans-scleral contact diode laser cyclophotocoagulation.

    PubMed

    Gupta, Viney; Sony, Parul; Sihota, Ramanjit

    2006-01-01

    A 22-year-old woman underwent 360 degrees trans-scleral contact diode laser cyclophotocoagulation for refractory glaucoma. Conjunctival burns and scleral thinning were noticed inferonasally at the last laser application. Intraocular pressure in the first week was normal. Six months later the patient presented with encysted filtering bleb and high intraocular pressure. Ultrasound biomicroscopy revealed a full thickness sclerostomy. This report suggests that inadvertent sclerostomy may present with encysted bleb months after trans-scleral contact diode laser cyclophotocoagulation.

  10. Trans-scleral tactile tonometry: an instrumented approach.

    PubMed

    Polyvás, Péter P; Peyman, Gholam; Enikov, Eniko T

    2013-07-01

    This article describes a feasibility study of a novel trans-scleral tonometer based on the use of an instrumented form of digital palpation tonometry. Similar to manual digital palpation tonometery, trans-scleral tonometer utilizes two force probes offset by a fixed distance. Force indentation data from these probes have been shown to correlate with the intraocular pressure (IOP) of the eye. Enucleated porcine eyes were used to experimentally validate the approach. The observed hysteresis in the force data was analyzed using an analytical model that accounts for the outflow of the aqueous humor. The predictions of the model indicate that the primary reason behind the observed hysteresis is stress relaxation (accommodation) in the visco-elastic corneo-scleral shell. Experimental data from eye distention and indentation tests were then used to infer the conditions under which the novel tonometer would be expected to have an accuracy of ±1 mmHg. Analysis of the data shows that indentation rates should be kept below 0.5 mm/s for a pressure range of 10-35 mmHg. Two commonly used pressure control protocols were tested in an effort to ensure accurate IOP values during the palpation tests. Due to the large increase of IOP during digital palpation, the trans-scleral (intra-vitreous) pressurization was found to be inadequate, leading to clogging of the line by the displaced vitreous. No such problems were identified when the eye was pressurized through the cornea and into the anterior chamber. Force data from multiple palpation experiments are used to generate calibration curves for a two-probe conceptual tonometer. The calibration showed that a 10 mN of force variation corresponds to 1 mmHg of IOP change. A possible implementation using a contoured facial mask is also presented.

  11. Posterior vitreous wick syndrome: a potential cause of endophthalmitis following vitreo-retinal surgery.

    PubMed

    Venkatesh, P; Verma, L; Tewari, H

    2002-06-01

    Endophthalmitis following pars-plana procedures such as a vitrectomy vitreo-retinal procedures has been infrequently reported in literature. The cited incidence is about 0.1% to 0.2%. In the 8 cases of endophthalmitis that have been reported in literature, the prognosis has been indicated as very poor due to a delay in diagnosis (1-3). Also, no possible source of an inoculum of the pathogenic organism reaching the vitreous cavity has been considered in these reports. We have encountered a few cases of endophthalmitis following vitreo-retinal surgeries at our tertiary eye care centre. Here again not being able to identify the possible source of infectious spread, we now report for the first time in literature, a new entity, the 'posterior vitreous wick syndrome'. This potential source of infectious spread, to the best of our knowledge, has not been considered earlier. We describe the patho-mechanism of the 'posterior vitreous wick syndrome' and also suggest methods of reducing its occurrence during vitreo-retinal procedures. This could also be the patho-mechanism of endophthalmitis following inadvertent loss of scleral integrity during extraocular surgeries like retinal detachment surgery and strabismus surgery (4,5).

  12. Biomechanical Properties and Correlation With Collagen Solubility Profile in the Posterior Sclera of Canine Eyes With an ADAMTS10 Mutation

    PubMed Central

    Palko, Joel R.; Iwabe, Simone; Pan, Xueliang; Agarwal, Gunjan; Komáromy, András M.; Liu, Jun

    2013-01-01

    Purpose. We examined the biomechanical properties and correlation with the collagen solubility profile of the posterior sclera in a canine model of primary open-angle glaucoma caused by the G661R missense mutation in the ADAMTS10 gene. Methods. Scleral strips from ADAMTS10-mutant (affected) dogs and age-matched controls were collected. Viscoelastic properties (i.e., complex modulus and tan[δ]) were measured using dynamic mechanical analysis (DMA) with a 0.15% sinusoidal strain at different frequencies superimposed upon different preloads. A tensile ramp was performed following DMA. The collagen solubility profile was examined using a colorimetric hydroxyproline assay to determine the amount of soluble and insoluble collagen. The viscoelastic properties were compared between groups using linear mixed models for repeated measures at different preloads and frequencies. The correlation between the biomechanical properties and collagen content were evaluated using Pearson correlations. Results. Complex modulus and tan(δ) were significantly lower in the affected group (P < 0.001), and the differences were consistent at different preloads and frequencies. The B value from the tensile ramp test also was significantly lower in the affected group (P = 0.02). The insoluble collagen was significantly lower in the affected group (P < 0.05) and correlated positively with the complex modulus (R = 0.88, P < 0.005). Conclusions. An inherently weaker and biochemically distinct posterior sclera was observed in dogs with the G661R missense mutation in ADAMTS10 before clinical indications of optic nerve damage. It remains to be shown whether and how the altered scleral biomechanics may affect the rate of glaucoma progression following intraocular pressure elevation. PMID:23518772

  13. Quantification of the role of tibial posterior slope in knee joint mechanics and ACL force in simulated gait.

    PubMed

    Marouane, H; Shirazi-Adl, A; Hashemi, J

    2015-07-16

    The anterior cruciate ligament (ACL) rupture is a common knee joint injury with higher prevalence in female athletes. In search of contributing mechanisms, clinical imaging studies of ACL-injured individuals versus controls have found greater medial-lateral posterior tibial slope (PTS) in injured population irrespective of the sex and in females compared to males, with stronger evidence on the lateral plateau slope. To quantify these effects, we use a lower extremity musculoskeletal model including a detailed finite element (FE) model of the knee joint to compute the role of changes in medial and/or lateral PTS by ±5° and ±10° on knee joint biomechanics, in general, and ACL force, in particular, throughout the stance phase of gait. The model is driven by reported kinematics/kinetics of gait in asymptomatic subjects. Our predictions showed, at all stance periods, a substantial increase in the anterior tibial translation (ATT) and ACL force as PTS increased with reverse trends as PTS decreased. At mid-stance, for example, ACL force increased from 181 N to 317 N and 460 N as PTS increased by 5° and 10°, respectively, while dropped to 102 N and 0 N as PTS changed by -5° and -10°, respectively. These effects are caused primarily by change in PTS at the tibial plateau that carries a larger portion of joint contact force. Steeper PTS is a major risk factor, especially under activities with large compression, in markedly increasing ACL force and its vulnerability to injury. Rehabilitation and ACL injury prevention programs could benefit from these findings.

  14. 78 FR 68714 - Medical Devices; Ophthalmic Devices; Classification of the Scleral Plug

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ... controls), and exempting the scleral plugs composed of surgical grade stainless steel (with or without... from surgical grade stainless steel (with or without a gold, silver, or titanium coating). The Agency... scleral plugs made from surgical grade stainless steel (with or without a gold, silver, or...

  15. Scleral and suprachoroidal foreign body in a dog--a case report.

    PubMed

    Welihozkiy, Anja; Pirie, Christopher G; Pizzirani, Stefano

    2011-09-01

    A 2-year-old male castrated Springer Spaniel with a 3-week history of waxing and waning right sided exophthalmos, periorbital swelling, chemosis, and fundic changes was examined. Ophthalmic examination of the right eye revealed slight chemosis and nictitating membrane protrusion. Indirect ophthalmoscopy showed an approximately 8 mm peripapillary hyporeflective tapetal lesion with subretinal edema consistent with a bulbar/retrobulbar disease process. Inflammatory or neoplastic diseases were the main differential diagnoses. Ancillary diagnostics (ocular ultrasound and computed tomography) showed a focal, poorly defined dense tissue involving the caudomedial aspect of the right globe, adjacent to the optic nerve head without apparent orbital involvement. Considering the duration, location, and severity of the clinical findings, enucleation of the right globe was performed. Histopathology revealed focal thickening of the posterior wall with severe pyogranulomatous inflammation, surrounding a foreign body most consistent with plant material embedded between the sclera and the choroid (suprachoroidal). This report describes a rare case of a scleral/suprachoroidal foreign body (plant material), and outlines the difficulty of establishing an etiological diagnosis using standard ocular imaging.

  16. Intraoperative electrophysiological evaluations of macular function during peripheral scleral indentation

    PubMed Central

    Akiyama, Goichi; Matsumoto, Celso Soiti; Shinoda, Kei; Terauchi, Gaku; Matsumoto, Harue; Watanabe, Emiko; Iwata, Takeshi; Mizota, Atsushi; Miyake, Yozo

    2016-01-01

    Scleral indentation is widely used to examine the peripheral fundus, however it can increase the intraocular pressure (IOP) to high levels which can then affect retinal function. We evaluated the effects of scleral indentation on the macular function electrophysiologically. Intraoperative focal macular electroretinograms (iFMERGs) were recorded with and without controlling the IOP in 7 eyes. Without IOP control, the IOP increased from 21.7 ± 4.9 to 92.7 ± 20.2 mmHg significantly (P = 0.020) and the amplitudes of the b-wave (from 6.29 ± 1.160 to 3.71 ± 1.98 uV, P = 0.007), on-photopic negative response (from 2.29 ± 0.99 to 0.72 ± 0.47 uV, on-PhNR, P = 0.005), and d-wave (from 2.57 ± 0.41 to 1.64 ± 0.69 uV, P = 0.007) decreased significantly soon after beginning the indentation. All values returned to the baseline levels after releasing the indentation. In the eyes with IOP controlled, the IOP and the amplitude of all components did not change significantly during and after the indentation except the on-PhNR amplitude which was significantly reduced during the indentation. The changes in the iFMERGs and macular function caused by scleral indentation were transient and reversible. The changes can be minimized by controlling the IOP. PMID:27762313

  17. The influence of scleral flap thickness, shape, and sutures on intraocular pressure (IOP) and aqueous humor flow direction in a trabeculectomy model

    PubMed Central

    Samsudin, Amir; Eames, Ian; Brocchini, Steve; Khaw, Peng Tee

    2015-01-01

    Purpose IOP and aqueous humor flow direction determined by the scleral flap immediately after trabeculectomy are critical determinants of the surgical outcome. We used a large-scale model to objectively measure the influence of flap thickness and shape, and suture number and position on pressure difference across the flap and flow of fluid underneath it. Methods The model exploits the principle of dynamic and geometric similarity, so while dimensions were up to 30× greater than actual, the flow had similar properties. Scleral flaps were represented by transparent 0.8 and 1.6 mm thick silicone sheets on an acrylic plate. Dyed 98% glycerine, representing the aqueous humor was pumped between the sheet and plate, and the equilibrium pressure measured with a pressure transducer. Image analysis based on the principle of dye dilution was performed using MATLAB software. Results The pressure drop across the flap was larger with thinner flaps, due to reduced rigidity and resistance. Doubling the surface area of flaps and reducing the number of sutures from 5 to 3 or 2 also resulted in larger pressure drops. Flow direction was affected mainly by suture number and position, it was less towards the sutures and more towards the nearest free edge of the flap. Posterior flow of aqueous humor was promoted by placing sutures along the sides while leaving the posterior edge free. Conclusion We demonstrate a new physical model which shows how changes in scleral flap thickness and shape, and suture number and position affect pressure and flow in a trabeculectomy. PMID:26561421

  18. PROSE scleral lens: a novel aid for staged eyelid reconstruction.

    PubMed

    Samimi, David B; Chiu, Gloria B; Burnstine, Michael A

    2014-01-01

    A 50-year-old man presented with a papillomatous tarsoconjunctival tumor involving the medial two-thirds of the left upper eyelid. Office biopsy revealed papillary squamous cell carcinoma (SCCA). Rapid tumor growth with caruncular and forniceal conjunctival involvement continued, despite a trial of weekly interferon-α2b intralesional injection therapy. Surgical excision with clear margins resulted in a large upper eyelid defect. The suspicion for recurrence remained, given the aggressive nature of the tumor. A temporary prosthetic replacement of the ocular surface ecosystem (PROSE) scleral lens was fit for preservation of the ocular surface and visual function during a 1-month observation period. No evidence of recurrence was noted, and the eyelid defect was successfully reconstructed with a Cutler-Beard procedure. Local disease was controlled; unfortunately, metastatic disease was found in the ipsilateral parotid gland 1 year later. Aggressive surgical removal is recommended in interferon-α2b nonresponsive SCCA tumors. The PROSE scleral contact lens may serve as a useful adjunct for the maintenance of a healthy ocular surface and visual function during delayed eyelid defect repair.

  19. Posterior crossbites in children.

    PubMed

    Zhu, J F; Crevoisier, R; King, D L; Henry, R; Mills, C M

    1996-11-01

    Posterior crossbite, the most common malocclusion in young children, can be caused by a variety of skeletal, muscular, or dental factors. This condition produces insufficient maxillary arch width and is frequently associated with various oral sucking and postural habits. If left untreated, this problem can result in adverse skeletal growth changes. Various mechanical treatment modalities designed to expand the posterior maxillary arch width are available to correct this problem. The appropriate treatment method depends on the patient's age and level of cooperation as well as the determined etiology of the constriction.

  20. Risk factors influencing the outcome of strabismus surgery following retinal detachment surgery with scleral buckle

    PubMed Central

    Rabinowitz, Ronen; Velez, Federico G.; Pineles, Stacy L.

    2013-01-01

    Purpose To determine factors associated with surgical success in patients undergoing strabismus surgery after retinal detachment repair with scleral buckle. Methods The medical records of consecutive patients who underwent strabismus surgery after repair of retinal detachment with scleral buckle were retrospectively reviewed. A successful “motor” outcome was defined as horizontal deviation <10Δ and vertical deviation <4Δ in the primary position; successful “sensory” outcome was no diplopia in the primary position. Various factors such as removing the scleral buckle at the time of strabismus surgery, the macula structural status, size of the preoperative deviation, presence of restriction to passive movement, and whether the eye with the scleral buckle was the operated eye were compared among groups based on motor success. Results A total of 25 patients were included. The overall motor success rate was 72% after 1.8 ± 0.9 operations, with 62% of patients diplopia free in the primary position. Horizontal deviation <10Δ (P = 0.005) and minimal restriction on forced duction test were associated with motor success after the first surgery (P = 0.05). Partial or entire scleral buckle removal (n = 15) and fellow-eye surgery were not significantly correlated with motor success in our cohort. There were no retinal redetachments after scleral buckle removal. Conclusions A small preoperative horizontal deviation, and minimally restricted ocular rotations were associated with better results. Removing the scleral buckle did not improve results. PMID:24215808

  1. Nocturnality in dinosaurs inferred from scleral ring and orbit morphology.

    PubMed

    Schmitz, Lars; Motani, Ryosuke

    2011-05-06

    Variation in daily activity patterns facilitates temporal partitioning of habitat and resources among species. Knowledge of temporal niche partitioning in paleobiological systems has been limited by the difficulty of obtaining reliable information about activity patterns from fossils. On the basis of an analysis of scleral ring and orbit morphology in 33 archosaurs, including dinosaurs and pterosaurs, we show that the eyes of Mesozoic archosaurs were adapted to all major types of diel activity (that is, nocturnal, diurnal, and cathemeral) and provide concrete evidence of temporal niche partitioning in the Mesozoic. Similar to extant amniotes, flyers were predominantly diurnal; terrestrial predators, at least partially, nocturnal; and large herbivores, cathemeral. These similarities suggest that ecology drives the evolution of diel activity patterns.

  2. Macular Hole Formation in Rhegmatogenous Retinal Detachment after Scleral Buckling

    PubMed Central

    Byon, Ik Soo; Kwon, Han Jo; Park, Gun Hyung; Park, Sung Who

    2014-01-01

    Purpose To describe early macular hole (MH) development in rhegmatogenous retinal detachment (RRD) after scleral buckling (SB) based on optical coherence tomography (OCT) findings. Methods The medical records and spectral domain OCT images of patients in whom MH developed after RRD repair were evaluated retrospectively. Results A postoperative MH was detected in five eyes that underwent SB during a 6-year period. All had fovea-off RRD without MH at the time of surgery. OCT showed partial loss of the inner retina with a preserved photoreceptor layer in early postoperative days. On average, 7 days (range,5 to 8 days) after surgery, outer retinal tissues disappeared, resulting in the full-thickness MH. Conclusions Serial OCT findings revealed that partial-thickness lamellar holes progressed to full-thickness MHs, which were formed by the degeneration of the outer retina in eyes with preceding loss of the glial cone in the fovea. PMID:25276077

  3. Short-term effect of cryotherapy on human scleral tissue by atomic force microscopy.

    PubMed

    Lee, Seung Jun; Choi, Samjin; Kim, Moo Sang; Cheong, Youjin; Kwak, Hyung-Woo; Park, Hun-Kuk; Jin, Kyung-Hyun

    2013-01-01

    This study investigated the inflammatory effect of cryotherapy application on collagen matrix network in human infant sclera. Donor scleral tissues taken from three infant patients divided into five groups: control group, sham-treated group, and three cryotreated groups. In the cryotherapy groups, the sclera was treated for 5 s, 10 s, and 20 s with -80°C freezing by a cryosurgical system. The cryotreated reactions were examined using double histological analysis with hematoxylin-eosin and Masson's trichrome, and atomic force microscopy analysis to quantify the diameter and D-banding of collagen fibrils. The infant scleral tissues treated with cryotherapy showed a significantly increased collagen density associated with inflammatory response (p < 0.05), increased fibril diameter (p < 0.005) compared to the scleral tissues in the control group. The results directly suggest that the cryotherapy affects the morphology of scleral collagen.

  4. Endoillumination (chandelier) assisted scleral buckling for a complex case of retinal detachment.

    PubMed

    Temkar, Shreyas; Takkar, Brijesh; Azad, Shorya Vardhan; Venkatesh, Pradeep

    2016-11-01

    Endoilluminator-assisted scleral buckling combines the advantages of scleral buckling for its external approach and pars plana vitrectomy for its better visual visualization in the management of retinal detachment (RD). It has recently been proven to be safe and efficacious in simple cases. This report discusses successful management of a complex case of RD in a patient with the single functioning eye, where vitrectomy was expected to have a complicated course.

  5. Endoillumination (chandelier) assisted scleral buckling for a complex case of retinal detachment

    PubMed Central

    Temkar, Shreyas; Takkar, Brijesh; Azad, Shorya Vardhan; Venkatesh, Pradeep

    2016-01-01

    Endoilluminator-assisted scleral buckling combines the advantages of scleral buckling for its external approach and pars plana vitrectomy for its better visual visualization in the management of retinal detachment (RD). It has recently been proven to be safe and efficacious in simple cases. This report discusses successful management of a complex case of RD in a patient with the single functioning eye, where vitrectomy was expected to have a complicated course. PMID:27958210

  6. Corneal perforation during scleral indentation in a patient with pellucid marginal degeneration

    PubMed Central

    Mercieca, Karl; Dharmasena, Aruna; Hopley, Charles

    2016-01-01

    An observational case report of corneal perforation following scleral indentation in a patient with previously undiagnosed pellucid marginal degeneration is presented. Clinical examination, investigations, and subsequent management of this unwarranted and rare complication are described and discussed. The case highlights the need for thorough anterior segment examination before indirect ophthalmoscopy particularly in the presence of ectatic corneal pathology in which case scleral indentation should be avoided. PMID:27146937

  7. Mechanical and biological complication rates of the modified lateral-screw-retained implant prosthesis in the posterior region: an alternative to the conventional Implant prosthetic system

    PubMed Central

    2016-01-01

    PURPOSE The modified lateral-screw-retained implant prosthesis (LSP) is designed to combine the advantages of screw- and cement-retained implant prostheses. This retrospective study evaluated the mechanical and biological complication rates of implant-supported single crowns (ISSCs) inserted with the modified LSP in the posterior region, and determined how these complication rates are affected by clinical factors. MATERIALS AND METHODS Mechanical complications (i.e., lateral screw loosening [LSL], abutment screw loosening, lateral screw fracture, and ceramic fracture) and biological complications (i.e., peri-implant mucositis [PM] and peri-implantitis) were identified from the patients' treatment records, clinical photographs, periapical radiographs, panoramic radiographs, and clinical indices. The correlations between complication rates and the following clinical factors were determined: gender, age, position in the jaw, placement location, functional duration, clinical crown-to-implant length ratio, crown height space, and the use of a submerged or nonsubmerged placement procedure. RESULTS Mechanical and biological complications were present in 25 of 73 ISSCs with the modified LSP. LSL (n=11) and PM (n=11) were the most common complications. The incidence of mechanical complications was significantly related to gender (P=.018). The other clinical factors were not significantly associated with mechanical and biological complication rates. CONCLUSION Within the limitations of this study, the incidence of mechanical and biological complications in the posterior region was similar for both modified LSP and conventional implant prosthetic systems. In addition, the modified LSP is amenable to maintenance care, which facilitates the prevention and treatment of mechanical and biological complications. PMID:27141260

  8. Estimation of axial curvature of anterior sclera: correlation between axial length and anterior scleral curvature as affected by angle kappa.

    PubMed

    Lee, Sang-Mok; Choi, Hyuk Jin; Choi, Heejin; Kim, Mee Kum; Wee, Won Ryang

    2016-10-07

    BACKGROUND: Though the development and fitting of scleral contact lenses are expanding steadily, there is no simple method to provide scleral metrics for scleral contact lens fitting yet. The aim of this study was to establish formulae for estimation of the axial radius of curvature (ARC) of the anterior sclera using ocular biometric parameters that can be easily obtained with conventional devices.

  9. Posterior rat eye during acute intraocular pressure elevation studied using polarization sensitive optical coherence tomography

    PubMed Central

    Fialová, Stanislava; Augustin, Marco; Fischak, Corinna; Schmetterer, Leopold; Handschuh, Stephan; Glösmann, Martin; Pircher, Michael; Hitzenberger, Christoph K.; Baumann, Bernhard

    2016-01-01

    Polarization sensitive optical coherence tomography (PS-OCT) operating at 840 nm with axial resolution of 3.8 µm in tissue was used for investigating the posterior rat eye during an acute intraocular pressure (IOP) increase experiment. IOP was elevated in the eyes of anesthetized Sprague Dawley rats by cannulation of the anterior chamber. Three dimensional PS-OCT data sets were acquired at IOP levels between 14 mmHg and 105 mmHg. Maps of scleral birefringence, retinal nerve fiber layer (RNFL) retardation and relative RNFL/retina reflectivity were generated in the peripapillary area and quantitatively analyzed. All investigated parameters showed a substantial correlation with IOP. In the low IOP range of 14-45 mmHg only scleral birefringence showed statistically significant correlation. The polarization changes observed in the PS-OCT imaging study presented in this work suggest that birefringence of the sclera may be a promising IOP-related parameter to investigate. PMID:28101419

  10. The comparison of retinal blood flow after scleral buckling surgery with or without encircling procedure

    PubMed Central

    Dehghani, Alireza; Razmjoo, Hassan; Fazel, Farhad; Karami, Mehdi; Etesampour, Akbar; Ghanbari, Heshmatolah; Kianersi, Farzan; Akhlaghi, Mohammadreza; Fesharaki, Hamid

    2013-01-01

    Aim: We aimed to compare peak systolic velocity of central retinal artery (PSV.CRA) and peak systolic velocity of ophthalmic artery (PSV.OA) between patients with retinal detachment who were treated with segmental scleral bucking and scleral buckling with encircling procedure. Materials and Methods: This study was a descriptive-analytic cross sectional study that was performed in Isfahan university referral centers since April 2010 to April 2011. Of the patients who have undergone scleral buckling surgery, 20 patients belonging to two groups were randomly selected to enroll in the study. Study groups were, patients who have undergone segmental scleral buckling and the other group were patients who have undergone scleral buckling with encircling procedure. Patients were invited to perform color Doppler imaging. PSV-RA and PSV-OA were measured and documented in both operated and unoperated eyes. All of the Doppler's performed at least three months after ophthalmic surgery. Results: We found significant decrease in PSV.CRA among patients in both groups. In patients who had undergone scleral buckling with encircling procedure PSV.CRA was 11.03 ± 3.04 (cm/sec) and 14.83 ± 4.80 in operated and unoperated eye respectively (P = 0.03). In other hand, who treated with segmental scleral buckling these parameters were 11.02 ± 2.48 and 14.45 ± 4.69 (P = 0.03). PSV.OA did not change significantly in each method. The difference between mean PSV.CRA and PSV.OA in operated eye between two study groups was not significant. Conclusion: PSV.CRA reduced significantly in both surgery methods and PSV.OA changes was not significant. However, the mean PSV.CRA and PSV.OA changes did not show statistically significant difference between surgery methods. PMID:23930119

  11. Effects of Peripapillary Scleral Stiffening on the Deformation of the Lamina Cribrosa

    PubMed Central

    Coudrillier, Baptiste; Campbell, Ian C.; Read, A. Thomas; Geraldes, Diogo M.; Vo, Nghia T.; Feola, Andrew; Mulvihill, John; Albon, Julie; Abel, Richard L.; Ethier, C. Ross

    2016-01-01

    Purpose Scleral stiffening has been proposed as a treatment for glaucoma to protect the lamina cribrosa (LC) from excessive intraocular pressure–induced deformation. Here we experimentally evaluated the effects of moderate stiffening of the peripapillary sclera on the deformation of the LC. Methods An annular sponge, saturated with 1.25% glutaraldehyde, was applied to the external surface of the peripapillary sclera for 5 minutes to stiffen the sclera. Tissue deformation was quantified in two groups of porcine eyes, using digital image correlation (DIC) or computed tomography imaging and digital volume correlation (DVC). In group A (n = 14), eyes were subjected to inflation testing before and after scleral stiffening. Digital image correlation was used to measure scleral deformation and quantify the magnitude of scleral stiffening. In group B (n = 5), the optic nerve head region was imaged using synchrotron radiation phase-contrast microcomputed tomography (PC μCT) at an isotropic spatial resolution of 3.2 μm. Digital volume correlation was used to compute the full-field three-dimensional deformation within the LC and evaluate the effects of peripapillary scleral cross-linking on LC biomechanics. Results On average, scleral treatment with glutaraldehyde caused a 34 ± 14% stiffening of the peripapillary sclera measured at 17 mm Hg and a 47 ± 12% decrease in the maximum tensile strain in the LC measured at 15 mm Hg. The reduction in LC strains was not due to cross-linking of the LC. Conclusions Peripapillary scleral stiffening is effective at reducing the magnitude of biomechanical strains within the LC. Its potential and future utilization in glaucoma axonal neuroprotection requires further investigation. PMID:27183053

  12. Differential effects of aging on transport properties of anterior and posterior human sclera.

    PubMed

    Boubriak, O A; Urban, J P G; Bron, A J

    2003-06-01

    The transport properties and composition of 44 pairs of human sclera, 37-91 years were compared. Solute transport, diffusion and partition coefficients of posterior sclera for solutes ranging in mass from 0.023-70kDa were higher than those of anterior sclera; the posterior region was also more hydrated. The differences in partition coefficient between anterior and posterior sclera became more pronounced as solute molecular weight increased. Partition coefficients and hydration of both regions decreased with increasing age. Chondroitinase ABC digestion, which removed the majority of glycosaminoglycans, increased partition coefficients of both regions significantly. These results suggest that for regions of equal scleral thickness, neglecting the influence of vascular factors, drug delivery will be more readily achieved across the posterior sclera than the anterior sclera in the age group studied and that, for both regions, ease of delivery will decrease with decreasing age.

  13. Laser-induced scleral shrinkage for refractive surgery

    NASA Astrophysics Data System (ADS)

    Ren, Qiushi; Simon, Gabriel; Parel, Jean-Marie A.; Shen, Jin-Hui

    1994-06-01

    We investigate the laser refractive scleroplasty (LRS) as a potential minimal-invasive method for correcting post-operative astigmatism. The scleral shrinkage near limbus was induced on 6 cadaver eyes using a 200 micrometers fiber optic probe coupled to a pulsed Ho:YAG laser. The diameter of the treatment spot was 0.8 mm. The output energy measured at tip was 60.2+/- 0.6 mJ. The treatments consisted of multiple sector patterns placed along the major axis of astigmatism parallel to the limbus, and round patterns placed along the limbus. Three treatment spots were applied on each side of the sector. The separation among sectors and limbus is 1 mm. Keratometry and topography of the cornea were measured after each sector or round pattern treatment. Effect of 5 and 10 pulses at each treatment spot were compared. Histology was performed to evaluate laser tissue damage. The major axis of astigmatism was shifted 90 degrees after the sector pattern treatment and amount of dioptric change increased when adding a new treatment or using more treatment pulses. However, the spherical equivalent of the eyes was essentially unchanged. The keratometry of the corneas remained the same after the round pattern treatment. Laser refractive scleroplasty may be applied for the correction of post-operative astigmatism.

  14. Scleral Buckling for Rhegmatogenous Retinal Detachment Associated with Pars Planitis

    PubMed Central

    Ahn, Jae Kyoun

    2016-01-01

    Purpose. To evaluate the surgical outcome of scleral buckling (SB) in rhegmatogenous retinal detachment (RRD) patients associated with pars planitis. Methods. Retrospective review of RRD patients (32 eyes of pars planitis RRD and 180 eyes of primary RRD) who underwent SB. We compared primary and final anatomical success rates and visual outcomes between two groups. Results. Primary and final anatomical success were achieved in 25 (78.1%) and 31 (96.8%) eyes in the pars planitis RRD group and in 167 eyes (92.7%) and 176 eyes (97.7%) in primary RRD group, respectively. Both groups showed significant visual improvement (p < 0.001) and there were no significant differences in final visual acuity. Pars planitis RRD group was associated with higher rate of postoperative proliferative vitreoretinopathy (PVR) development (12.5% versus 2.8%, p = 0.031). Pars planitis and high myopia were significant preoperative risk factors and pseudophakia was borderline risk for primary anatomical failure after adjusting for various clinical factors. Conclusions. Pars planitis associated RRD showed inferior primary anatomical outcome after SB due to postoperative PVR development. However, final anatomical and visual outcomes were favorable. RRD cases associated with pars planitis, high myopia, and pseudophakia might benefit from different surgical approaches, such as combined vitrectomy and SB. PMID:27688907

  15. Impact of Mitomycin-C application time on the scleral Mitomycin-C concentration.

    PubMed

    Vass, C; Georgopoulos, M; El Menyawi, I; Radda, S; Nimmerrichter, P

    2001-04-01

    The aim of this study was to determine the effect of varying the application time of Mitomycin-C (MMC) on the scleral concentration of MMC. The sclerae of 14 human donor eyes were used for this study. The episcleral sides of the 4 scleral quadrants of each donor eye were exposed for 0.5, 1, 3 and 5 min to round, 8 mm-diameter sponges soaked with 50 microl of 0.2 mg/ml MMC. After 40-ml irrigation with saline, a central 8-mm diameter scleral disk was punched out, homogenized and analyzed with high performance liquid chromatography (HPLC). The scleral MMC concentrations (microg/g) after 0.5, 1, 3 and 5 min application times were 6.40 (+/-3.38), 9.02 (+/-2.40), 12.31 (+/-3.37), and 13.97 (+/-3.83). The differences of scleral MMC concentration in paired t-tests were statistically significant comparing 0.5 with 1 and 1 with 5 min application. However the effect was relatively small within the range of usual application times (1 to 5 min), and 64% of the MMC was delivered to the sclera within the first min.

  16. Increase in scleral collagen stability during glycosylation with threose in vitro

    NASA Astrophysics Data System (ADS)

    Danilov, N. A.; Ignat'eva, N. Yu.; Iomdina, E. N.; Grokhovskaya, T. E.; Obrezkova, M. V.; Rudenskaya, G. N.; Lunin, V. V.

    2010-01-01

    A systematic study of changes in the physicochemical characteristics of scleral collagen in the course of glycosylation by threose, including their dependence on the time changes of transverse cross-linking, was performed. Glycosylation by threose leads to a significant increase in heat, proteolytic, and biomechanical stability of collagen in the scleral tissue and has been shown to be a useful approach for stabilizing scleral collagen. It was found that a fraction of collagen with a reduced denaturation temperature is, apparently, an intermediate in the reaction of glycosylation by threose. The most likely reason for its occurrence is the elongation of the side chains of amino acid residues of the protein in the early stages.

  17. Scleral Permeability Varies by Mouse Strain and Is Decreased by Chronic Experimental Glaucoma

    PubMed Central

    Pease, Mary E.; Oglesby, Ericka N.; Cone-Kimball, Elizabeth; Jefferys, Joan L.; Steinhart, Matthew R.; Kim, Anthony J.; Hanes, Justin; Quigley, Harry A.

    2014-01-01

    Purpose. To determine differences in scleral permeability, as measured by diffusion of macromolecules, by using fluorescence recovery after photobleaching (FRAP), with reference to differences by mouse strain, scleral region, and the effect of experimental glaucoma. Methods. In three mouse strains (B6, CD1, and B6 mice with mutation in collagen 8α2 [Aca23]), we used FRAP to measure the diffusion of fluorescein isothiocyanate–dextran, molecular weight 40 kDa, into a photobleached zone of sclera. Scleral regions near the optic nerve head (peripapillary) and two successively more anterior regions were compared. Sclera from mouse eyes subjected to chronically elevated intraocular pressure after bead injection into the anterior chamber were compared to fellow eye controls. FRAP data were compared against estimated retinal ganglion cell axon loss in glaucomatous eyes. Results. Diffusion rates of dextran molecules in the sclera were significantly greater in Aca23 and B6 mice than in CD1 mice in a multivariate model adjusted for region and axial length (P < 0.0001). Dextran diffusion significantly decreased in glaucomatous eyes, and the decline increased with greater axon loss (P = 0.0003, multivariable model). Peripapillary scleral permeability was higher in CD1 than B6 and Aca23 mice (P < 0.05, multivariable model, adjusted by Bonferroni). Conclusions. Measurement of the diffusion rates of dextran molecules in the sclera showed that glaucoma leads to decreased scleral permeability in all three mouse strains tested. Among mouse strains tested, those that were more susceptible to glaucomatous loss of retinal ganglion cells had a lower scleral permeability at baseline. PMID:24557355

  18. An epibulbar chocolate cyst: a rare complication of silicone-based scleral buckle.

    PubMed

    Venkatesh, Pradeep; Gogia, Varun; Gupta, Shikha; Nayak, Bhagabat

    2015-08-03

    A patient with a history of vitreoretinal surgery presented with nasal dystopia, diplopia and epibulbar bluish black mass simulating a chocolate cyst in the right eye. After a non-conclusive ocular examination, he underwent CT of the orbit along with volume rendition and three-dimensional reconstruction, which demonstrated intact globe with laterally displaced band-buckle assembly along with peri-scleral buckle element (SBE) soft tissue proliferation. Imaging-assisted exploration of the lesion was performed and retained scleral buckle element (SBE) was removed in toto; thus relieving the patient long-standing dystopia.

  19. Percutaneous Posterior Calcaneal Osteotomy.

    PubMed

    Lui, Tun Hing

    2015-01-01

    Different types of posterior calcaneal osteotomy are used for calcaneal realignment in the management of hindfoot deformity. We describe a percutaneous technique of posterior calcaneal osteotomy that can be either a Dwyer-type closing wedge osteotomy or displacement osteotomy.

  20. Scleral necrosis in congenital erythropoietic porphyria: A case report and review of the literature.

    PubMed

    Agarwal, Shweta; Majumder, Parthopratim Dutta; Srinivasan, Bhaskar; Iyer, Geetha

    2015-01-01

    A 28-year-old presented with complaints of severe pain and redness in the left eye since 2 weeks. He had similar complaints in the right eye 2 years back for which he had undergone a scleral patch graft. Best corrected visual acuity was 20/20 in both eyes. The right had a well vascularized scleral graft and rest of the anterior segment was normal. The left eye had inferior conjunctival congestion with an area of the scleral melt with uveal show just temporal to the limbus in the interpalbebral area. The cornea was clear and anterior chamber was quiet in the left eye. Applanation tonometry and fundus evaluation were normal in both eyes. Physical examination revealed hyperpigmented skin lesion, hypertrichosis and absorption of distal phalanges. Laboratory, ocular and physical findings confirmed the diagnosis of congenital erythropoietic porphyria. He was on oral steroids 40 mg/day since 2 weeks and topical antibiotics and lubricants. He was advised to continue the same and was taken up for scleral patch graft with fibrin glue in the left eye. Postoperatively he was continued on topical and oral steroids and lubricants.3 weeks later the left eye had stabilized however patient came with a melt in the right eye. Since it was an early melt, we went ahead with cyanoacrylate glue and bandage contact lens in the right eye and started him on topical steroids for the right eye also. Three months later both the eyes were stable, and the patient was gradually tapered off the steroids.

  1. Wide-Angle Viewing System versus Conventional Indirect Ophthalmoscopy for Scleral Buckling.

    PubMed

    Tomita, Yohei; Kurihara, Toshihide; Uchida, Atsuro; Nagai, Norihiro; Shinoda, Hajime; Tsubota, Kazuo; Ozawa, Yoko

    2015-09-02

    Wide-angle viewing systems (WAVSs) were originally established for pars plana vitrectomy. However, their application to scleral buckling surgery was recently reported. In this study, we compared the outcomes of scleral buckling using a noncontact WAVS with that of scleral buckling using conventional indirect ophthalmoscopy for rhegmatogenous retinal detachment. The clinical records of 39 eyes (39 patients) with rhegmatogenous retinal detachment primarily treated between November 2012 and June 2014 at the Vitreo-Retina Surgical Division Clinic at the Department of Ophthalmology, Keio University Hospital were retrospectively reviewed. Scleral bucking was performed using WAVS with surgical placement of an endoilluminator in 16 eyes and indirect ophthalmoscopy in 23 eyes. The patients in these groups were consecutive over different intervals. The preoperative demographics, success rate of retinal reattachment, intraoperative findings, and postoperative complications were evaluated. There were no significant differences in pre- or postoperative conditions between groups, and similar surgical outcomes were achieved with the WAVS and conventional procedures. However, compared with the conventional procedure, the WAVS procedure resulted in fewer intraoperative corneal epithelial disorders (p = 0.049) and decreased the surgical duration of segmental buckling (p = 0.02); therefore, it may be suggested as an effective alternative procedure.

  2. Wide-Angle Viewing System versus Conventional Indirect Ophthalmoscopy for Scleral Buckling

    PubMed Central

    Tomita, Yohei; Kurihara, Toshihide; Uchida, Atsuro; Nagai, Norihiro; Shinoda, Hajime; Tsubota, Kazuo; Ozawa, Yoko

    2015-01-01

    Wide-angle viewing systems (WAVSs) were originally established for pars plana vitrectomy. However, their application to scleral buckling surgery was recently reported. In this study, we compared the outcomes of scleral buckling using a noncontact WAVS with that of scleral buckling using conventional indirect ophthalmoscopy for rhegmatogenous retinal detachment. The clinical records of 39 eyes (39 patients) with rhegmatogenous retinal detachment primarily treated between November 2012 and June 2014 at the Vitreo-Retina Surgical Division Clinic at the Department of Ophthalmology, Keio University Hospital were retrospectively reviewed. Scleral bucking was performed using WAVS with surgical placement of an endoilluminator in 16 eyes and indirect ophthalmoscopy in 23 eyes. The patients in these groups were consecutive over different intervals. The preoperative demographics, success rate of retinal reattachment, intraoperative findings, and postoperative complications were evaluated. There were no significant differences in pre- or postoperative conditions between groups, and similar surgical outcomes were achieved with the WAVS and conventional procedures. However, compared with the conventional procedure, the WAVS procedure resulted in fewer intraoperative corneal epithelial disorders (p = 0.049) and decreased the surgical duration of segmental buckling (p = 0.02); therefore, it may be suggested as an effective alternative procedure. PMID:26329974

  3. Fitting an MSD (mini scleral design) rigid contact lens in advanced keratoconus with INTACS.

    PubMed

    Dalton, Kristine; Sorbara, Luigina

    2011-12-01

    Keratoconus is a bilateral degenerative disease characterized by a non-inflammatory, progressive central corneal ectasia (typically asymmetric) and decreased vision. In its early stages it may be managed with spectacles and soft contact lenses but more commonly it is managed with rigid contact lenses. In advanced stages, when contact lenses can no longer be fit, have become intolerable, or corneal damage is severe, a penetrating keratoplasty is commonly performed. Alternative surgical techniques, such as the use of intra-stromal corneal ring segments (INTACS) have been developed to try and improve the fit of rigid contact lenses in keratoconic patients and avoid penetrating keratoplasties. This case report follows through the fitting of rigid contact lenses in an advanced keratoconic cornea after an INTACS procedure and discusses clinical findings, treatment options, and the use of mini-scleral and scleral lens designs as they relate to the challenges encountered in managing such a patient. Mini-scleral and scleral lenses are relatively easy to fit, and can be of benefit to many patients, including advanced keratoconic patients, post-INTAC patients and post-penetrating keratoplasty patients.

  4. 78 FR 5327 - Medical Devices; Ophthalmic Devices; Classification of the Scleral Plug

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-25

    ... (special controls), and proposing to exempt the scleral plugs composed of surgical grade stainless steel... surgical grade stainless steel with or without a gold, silver, or titanium coating. B. Regulatory History... rooms. These devices are often made of surgical grade stainless steel and can be coated in gold,...

  5. Surgical treatment of necrotic scleral calcification using combined conjunctival autografting and an amniotic membrane inlay filling technique

    PubMed Central

    Kim, B-H

    2011-01-01

    Purpose To introduce a novel technique to treat necrotic scleral calcification caused by previous regional conjunctivectomy using conjunctival autografting and amniotic membrane inlay filling, and to evaluate the clinical outcome. Methods Ten patients (11 eyes, 12 regions) who had undergone regional conjunctivectomy with postoperative mitomycin C (MMC) for pterygia or pingueculae were included. Scleral calcification was removed using a bevel-down crescent knife. After the conjunctival donor tissue was harvested from the upper bulbar conjunctiva, the tissue was grafted to the scleral defect and secured with sutures. Amniotic membrane was inserted randomly into spaces between the conjunctival graft and the scleral bed. Protective amniotic membrane was transplanted over the graft, with stromal side up. Results Scleral calcification developed in ischaemic areas in 11 of the 12 regions; 50% of cases had a surface defect seen with a fluorescent dye. The grafted conjunctiva epithelialized successfully in all cases. In 10 regions, the epithelialization occurred in 1 or 2 weeks. In the remaining two regions, one region required another surgery because of graft failure, and epithelialization occurred in the last region in 9 weeks. Vascular growth into the graft from the surrounding tissue occurred in all cases in 1 to 10 weeks. The surgical wound stabilized 3 weeks postoperatively. Conclusion The combined technique had high success rates of graft survival and good revitalization of the necrotic area of scleral calcification, eliminated the need for invasive and time-consuming scleral autografting or allografting, and provided good cosmesis. Scleral ischaemia, which was caused by MMC, may induce scleral calcification. PMID:21869832

  6. A flattened retina-eyecup preparation suitable for electrophysiological studies of neurons visualized with trans-scleral infrared illumination.

    PubMed

    Hu, E H; Dacheux, R F; Bloomfield, S A

    2000-11-30

    We present an in vitro flattened retinal-scleral preparation suitable for electrophysiological studies from visually targeted amacrine and ganglion cells of the rabbit retina. In a newly designed superfusion chamber, the retinal-scleral tissue is stained with Azure B allowing for imaging of neurons in the ganglion cell layer with an infrared (IR)-sensitive CCD camera via trans-scleral IR illumination. Neurons can be visually identified and targeted for both extracellular and intracellular recordings made singly or in simultaneous pairs. The quality and stability of the recordings are excellent and the tissue remains viable for up to 10 h. This relatively simple preparation avoids the extensive surgical manipulations inherent to those based on isolated retinas or retinal slices. Moreover, the use of trans-scleral IR illumination rather than fluorescent dyes to visualize and target neurons allows for electrophysiological studies of the retina under controlled adaptational states including dark-adapted conditions.

  7. Complex Evolutionary and Genetic Patterns Characterize the Loss of Scleral Ossification in the Blind Cavefish Astyanax mexicanus

    PubMed Central

    O’Quin, Kelly E.; Doshi, Pooja; Lyon, Anastasia; Hoenemeyer, Emma; Yoshizawa, Masato; Jeffery, William R.

    2015-01-01

    The sclera is the tough outer covering of the eye that provides structural support and helps maintain intraocular pressure. In some fishes, reptiles, and birds, the sclera is reinforced with an additional ring of hyaline cartilage or bone that forms from scleral ossicles. Currently, the evolutionary and genetic basis of scleral ossification is poorly understood, especially in teleost fishes. We assessed scleral ossification among several groups of the Mexican tetra (Astyanax mexicanus), which exhibit both an eyed and eyeless morph. Although eyed Astyanax surface fish have bony sclera similar to other teleosts, the ossicles of blind Astyanax cavefish generally do not form. We first sampled cavefish from multiple independent populations and used ancestral character state reconstructions to determine how many times scleral ossification has been lost. We then confirmed these results by assessing complementation of scleral ossification among the F1 hybrid progeny of two cavefish populations. Finally, we quantified the number of scleral ossicles present among the F2 hybrid progeny of a cross between surface fish and cavefish, and used this information to identify quantitative trait loci (QTL) responsible for this trait. Our results indicate that the loss of scleral ossification is common–but not ubiquitous–among Astyanax cavefish, and that this trait has been convergently lost at least three times. The presence of wild-type, ossified sclera among the F1 hybrid progeny of a cross between different cavefish populations confirms the convergent evolution of this trait. However, a strongly skewed distribution of scleral ossicles found among surface fish x cavefish F2 hybrids suggests that scleral ossification is a threshold trait with a complex genetic basis. Quantitative genetic mapping identified a single QTL for scleral ossification on Astyanax linkage group 1. We estimate that the threshold for this trait is likely determined by at least three genetic factors which

  8. Ocular prosthesis incorporating IPS e-max press scleral veneer and a literature review on non-integrated ocular prosthesis

    PubMed Central

    Da Costa, Godwin Clovis; Aras, Meena Ajay; Chalakkal, Paul; Da Costa, Michelle Clovis

    2017-01-01

    The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a “cut-back” on a selected stock eye, insertion of the IPS e-max press scleral veneer, finishing and insertion. It also includes a detailed review on non-integrated ocular prostheses. PMID:28149792

  9. Ocular prosthesis incorporating IPS e-max press scleral veneer and a literature review on non-integrated ocular prosthesis.

    PubMed

    Da Costa, Godwin Clovis; Aras, Meena Ajay; Chalakkal, Paul; Da Costa, Michelle Clovis

    2017-01-01

    The article highlights a new method for the fabrication of an ocular prosthesis by the incorporation of a ceramic scleral veneer. The steps of fabrication include impression making, wax try-in, performing a "cut-back" on a selected stock eye, insertion of the IPS e-max press scleral veneer, finishing and insertion. It also includes a detailed review on non-integrated ocular prostheses.

  10. Comparison of iris-fixated foldable lens and scleral-fixated foldable lens implantation in eyes with insufficient capsular support

    PubMed Central

    Zhang, Han; Zhao, Jun; Zhang, Li-Jun; Liu, Jing; Liu, Yuan; Song, Wei; Tian, Qing-Fen; Wang, Qi; Hamilton, David-Rex

    2016-01-01

    AIM To compare the outcomes of vision using two different intraocular lens (IOL) replacement techniques, iris-fixated foldable intraocular lens (IF-IOL) and scleral-fixated foldable intraocular lens (SF-IOL) in patients with insufficient capsular support. METHODS Total 63 eyes (62 patients) with insufficient posterior capsule support underwent replacement of IF-IOL or SF-IOL between January 2008 and August 2011. Outcome measures included changes in visual acuity, slit lamp examination, refractive indices and corneal curvatures. RESULTS The mean improvement of uncorrected visual acuity (UCVA) was greater in IF-IOL group compared to the SF-IOL group (0.43 D±0.19 D vs 0.35 D±0.18 D, P<0.05). Moreover, 12 (38.71%) eyes in IF-IOL group and 4 (12.50%) in SF-IOL group had a higher postoperative UCVA than preoperative best corrected visual acuity (BCVA) while 9 (29.03%) eyes in IF-IOL group and 18 (56.25%) in SF-IOL group had a lower postoperative UCVA than preoperative BCVA. The myopic mean manifest sphere and mean cylinder magnitude were lower in the IF-IOL group than that in the SF-IOL group (-0.47 D±0.58 D vs 0.50 D±0.43 D, P<0.01; 0.84 D±0.53 D vs 1.23 D±0.70 D, P<0.05). No difference of corneal astigmatism and surgically induced astigmatism was found between the two groups. In addition, fewer complications were observed in IF-IOL eyes. CONCLUSION IF-IOL implantation can give a significant improvement in vision with fewer complications than SF-IOL in patients with insufficient capsular support. PMID:27990363

  11. Vestibulo-Oculomotor Reflex Recording Using the Scleral Search Coil Technique. Review of Peripheral Vestibular Disorders

    PubMed Central

    Boleas-Aguirre, Marisol; Migliaccio, Amerio A.; Carey, John P.

    2010-01-01

    Our goal is to review vestibulo-oculomotor reflex (VOR) studies on several peripheral vestibular disorders (Ménière’s disease, vestibular neuritis, benign paroxysmal positional vertigo, superior canal dehiscence syndrome, and vestibular neuroma), using the scleral search coil (SSC) technique. Head movements are detected by vestibular receptors and the elicited VOR is responsible for compensatory 3 dimensional eye movements. Therefore, to study the VOR it is necessary to assess the direction and velocity of 3 dimensional head, and eye movements. This can be achieved using the SSC technique. Interaction between a scleral search coil and an alternating magnetic field generates an electrical signal that is proportional to eye position. Ideally, eye rotation axis is aligned with head rotation axis and VOR gain (eye velocity/head velocity) for horizontal and vertical head rotations is almost 1. The VOR gain, however, for torsional head rotations is smaller and about 0.7. PMID:17683700

  12. Scleral necrosis in congenital erythropoietic porphyria: A case report and review of the literature

    PubMed Central

    Agarwal, Shweta; Majumder, Parthopratim Dutta; Srinivasan, Bhaskar; Iyer, Geetha

    2015-01-01

    A 28-year-old presented with complaints of severe pain and redness in the left eye since 2 weeks. He had similar complaints in the right eye 2 years back for which he had undergone a scleral patch graft. Best corrected visual acuity was 20/20 in both eyes. The right had a well vascularized scleral graft and rest of the anterior segment was normal. The left eye had inferior conjunctival congestion with an area of the scleral melt with uveal show just temporal to the limbus in the interpalbebral area. The cornea was clear and anterior chamber was quiet in the left eye. Applanation tonometry and fundus evaluation were normal in both eyes. Physical examination revealed hyperpigmented skin lesion, hypertrichosis and absorption of distal phalanges. Laboratory, ocular and physical findings confirmed the diagnosis of congenital erythropoietic porphyria. He was on oral steroids 40 mg/day since 2 weeks and topical antibiotics and lubricants. He was advised to continue the same and was taken up for scleral patch graft with fibrin glue in the left eye. Postoperatively he was continued on topical and oral steroids and lubricants.3 weeks later the left eye had stabilized however patient came with a melt in the right eye. Since it was an early melt, we went ahead with cyanoacrylate glue and bandage contact lens in the right eye and started him on topical steroids for the right eye also. Three months later both the eyes were stable, and the patient was gradually tapered off the steroids. PMID:26903733

  13. Drainage of subretinal fluidduring scleral buckling surgery for rhegmatogenous retinal detachment

    PubMed Central

    MALAGOLA, R.; PANNARALE, L.; TORTORELLA, P.; ARRICO, L.

    2015-01-01

    Background and objective The purpose of the study is to compare the drainage of subretinal fluid (SRF) in a scleral pocket (SP) with incision parallel to the limbus to drainage through a simple radial scleral thinning (ST), during scleral buckling surgery for rhegmatogenous retinal detachment (RRD). Patients and methods Retrospective cohort study of one hundred sixty-nine consecutive buckling surgery for RRD, where a drainage puncture was performed through SP in eighty-five cases and through previous radial ST in eighty-four cases. Results PT shows significant lower complication rate. The incidence of retinal incarceration or formation of a retinal hole at the first drainage site is lower in PT group (p=0.0285). During surgery choroidal detachment have been observed in a higher percentage of cases in the SP group (p=0.0379). At the end of the surgery a certain amount of SRF behind the buckling was significant in ST group (p=0.0026). Conclusion The SP drainage technique appears to be a useful, effective and safe method to drain SRF. PMID:26188754

  14. Scleral buckling procedure with chandelier illumination for pediatric rhegmatogenous retinal detachment

    PubMed Central

    Yokoyama, Toshiyuki; Kanbayashi, Koki; Yamaguchi, Tamaki

    2015-01-01

    Purpose To assess the treatment of pediatric patients with rhegmatogenous retinal detachment (RRD) by scleral buckling with chandelier illumination. Methods Three eyes were treated in three patients, healthy boys aged 7 years, 12 years, and 11 years, with RRD, macular involvement, and small retinal holes, of which two were preoperatively undetectable. Conventional scleral buckling with cryoretinopexy was performed under the contact lens for vitreous surgery or noncontact wide-angle viewing system using 27-gauge twin chandelier illumination. Results The only known predisposing factor for retinal detachment was myopia stronger than 3 D with lattice retinal degeneration in two of the three patients. Retinal reattachment was achieved in all cases without intra- or postoperative complications. However, visual recovery was limited in one of the three patients. Conclusion Scleral buckling with chandelier illumination is effective for pediatric RRD, especially if the retinal hole is difficult to detect preoperatively. However, visual recovery was sometimes limited because of macular involvement due to late diagnosis, which is one of the characteristic features of pediatric RRD. PMID:25657577

  15. A computational remodeling approach to predict the physiological architecture of the collagen fibril network in corneo-scleral shells.

    PubMed

    Grytz, Rafael; Meschke, Günther

    2010-04-01

    Organized collagen fibrils form complex networks that introduce strong anisotropic and highly nonlinear attributes into the constitutive response of human eye tissues. Physiological adaptation of the collagen network and the mechanical condition within biological tissues are complex and mutually dependent phenomena. In this contribution, a computational model is presented to investigate the interaction between the collagen fibril architecture and mechanical loading conditions in the corneo-scleral shell. The biomechanical properties of eye tissues are derived from the single crimped fibril at the micro-scale via the collagen network of distributed fibrils at the meso-scale to the incompressible and anisotropic soft tissue at the macro-scale. Biomechanically induced remodeling of the collagen network is captured on the meso-scale by allowing for a continuous re-orientation of preferred fibril orientations and a continuous adaptation of the fibril dispersion. The presented approach is applied to a numerical human eye model considering the cornea and sclera. The predicted fibril morphology correlates well with experimental observations from X-ray scattering data.

  16. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region.

    PubMed

    Sureda-Gómez, Miquel; Pascual-Carreras, Eudald; Adell, Teresa

    2015-11-05

    The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior) axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts) are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent) underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis.

  17. Microstructural Differences in the Human Posterior Sclera as a Function of Age and Race

    PubMed Central

    Yan, Dongmei; McPheeters, Sheridan; Johnson, Gregory; Utzinger, Urs

    2011-01-01

    Purpose. The purpose of this study was to quantify the age and race-related differences in the microstructural organization of the human posterior sclera. Such differences may contribute to the predisposition of primary open-angle glaucoma in various high-risk populations. Methods. Posterior–temporal scleras from 75 right eyes were procured at an average distance of 3.5 mm from the center of the optic nerve head (ONH). A light-scattering device was used to investigate the matrix organization of posterior scleral fibers around the ONH. In addition to the degree of alignment (via eccentricity), the percentage occurrence of fiber angles within equatorial and meridionally aligned bins was quantified as a function of depth, sex, age, and race. There were 20 African Americans, 55 Caucasians, 49 males, 26 females, in this study, all falling within three age groups (<30, n = 8; 30–60, n = 33; and >60 years, n = 34). Three scleral layers, normalized for depth, were examined. Results. For all ages and both races, fibers were preferentially oriented equatorially at all layers (P < 0.001). The African Americans had a significantly higher percentage of occurrence of meridional fibers than did the Caucasians (P < 0.001). The percentage occurrence of meridional fibers decreased significantly from the inner to the outer layers of the posterior sclera (P < 0.001). Conclusions. Statistically significant microstructural differences were found in the posterior sclera between African American and Caucasian donors. Ongoing work is focused on identifying whether such microstructural differences play a role in the higher prevalence of glaucoma in African American populations. PMID:21051726

  18. Posterior Cruciate Ligament Injury

    MedlinePlus

    ... ACL connect your thighbone (femur) to your shinbone (tibia). If either ligament is torn, it might cause ... ligaments connect the thighbone (femur) to the shinbone (tibia). The anterior and posterior cruciate ligaments form an " ...

  19. Posterior ankle impingement syndrome.

    PubMed

    Maquirriain, Javier

    2005-10-01

    Posterior ankle impingement syndrome is a clinical disorder characterized by posterior ankle pain that occurs in forced plantar flexion. The pain may be acute as a result of trauma or chronic from repetitive stress. Pathology of the os trigonum-talar process is the most common cause of this syndrome, but it also may result from flexor hallucis longus tenosynovitis, ankle osteochondritis, subtalar joint disease, and fracture. Patients usually report chronic or recurrent posterior ankle pain caused or exacerbated by forced plantar flexion or push-off maneuvers, such as may occur during dancing, kicking, or downhill running. Diagnosis of posterior ankle impingement syndrome is based primarily on clinical history and physical examination. Radiography, scintigraphy, computed tomography, and magnetic resonance imaging depict associated bone and soft-tissue abnormalities. Symptoms typically improve with nonsurgical management, but surgery may be required in refractory cases.

  20. Influence of Scleral Buckling Surgery with Encircling Band on Subfoveal Choroidal Thickness in Long-Term Observations

    PubMed Central

    Laudańska-Olszewska, Iwona; Gozdek, Piotr; Maroszyński, Mariusz; Amon, Michael

    2013-01-01

    Purpose. The aim of this study is the presentation of subfoveal choroidal thickness with enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) several months after scleral buckling with encircling band surgery. Methods. 48 patients who underwent scleral buckling with encircling band surgery for unilateral rhegmatogenous retinal detachment were included in the retrospective observational study. The mean time from scleral buckling surgery to the final EDI-OCT examination was 22±6.7 months. We compare choroidal thickness between operated and fellow eyes. Results. In all patients, the macula was detached before the surgery. The subfoveal choroidal thickness in 48 treated eyes was 260.9±45.8 µm (range 155–383 µm) and in the fellow eyes was 217.5±36.7 µm (range 98–326 µm). The subfoveal choroidal thickness of eyes after scleral buckling surgery in long-term EDI-OCT examination was significantly thicker (P<0.001) than in fellow eyes. Conclusions. The subfoveal choroid in eyes undergoing encircling band surgery was significantly thicker than in fellow eyes. We suspect that this may be the result of reduced choroidal blood flow. It also seems that the width and size of the material used in scleral buckling surgery may affect a change in the choroid circulation and increase subfoveal choroidal thickness. PMID:23841077

  1. Scleral Cross-Linking Using Riboflavin UVA Irradiation for the Prevention of Myopia Progression in a Guinea Pig Model: Blocked Axial Extension and Altered Scleral Microstructure

    PubMed Central

    Wang, Bingjie; Lin, Xiao; Wu, Yi; Liu, Hong; Qu, Xiaomei; Dai, Jinhui; Zhou, Xingtao; Zhou, Hao

    2016-01-01

    Purpose To develop methods of collagen cross-linking (CXL) in the sclera for the treatment of progressive myopia and to investigate the biomechanical and histological changes that occur in as a result. Methods Twenty 14-day-old guinea pigs were divided into 3 groups: the cross-linking group (CL, n = 8), non cross-linking group (NCL, n = 8), and control group (n = 4). The scleras of the right eyes of the guinea pigs in the CL group were surgically exposed and riboflavin was dropped onto the irradiation zone for 20 seconds prior to ultraviolet-A (UVA) irradiation. The same procedure was conducted on the NCL group but without UVA irradiation. No procedure was conducted on the control group. The right eyes of the guinea pigs in the CL and NCL groups were then fitted with -10.00DS optics for six weeks. Retinoscopy and the axial lengths (AXL) were measured at baseline, and at the second, fourth and sixth weeks post-treatment in all three groups. All animal subjects were euthanized after the sixth week and then biomechanical and histopathological examinations of the scleras were conducted. Results The mean AXL of the NCL group was longer than both the control and CL groups at six weeks (P = 0.001). The mean refractive error in the NCL group was statistically significantly more negative than both the control and the CL groups at six weeks (P = 0.001). The scleral collagen fiber arrangements of the CL and control groups were denser and more regularly distributed than the NCL group. Ultimate stress of the sclera was lowest in the NCL group, followed by the CL then the control group (P<0.05). Ultimate strain (%) of the sclera was lowest in the CL group followed by the NCL and then the control group (P<0.05). Conclusion Our study demonstrates that scleral CXL using riboflavin UVA irradiation effectively prevents the progression of myopia by increasing scleral biomechanical strength in a guinea pig model. PMID:27829051

  2. Effects of hepatocyte growth factor on MMP-2 expression in scleral fibroblasts from a guinea pig myopia model

    PubMed Central

    Li, Xiu-Juan; Yang, Xiao-Peng; Wan, Guang-Ming; Wang, Yu-Ying; Zhang, Jin-Song

    2014-01-01

    AIM To investigate the effects of hepatocyte growth factor (HGF) on MMP-2 expression in scleral fibroblasts from guinea pig with LIM. METHODS Sixty 1-week-old guinea pigs were chosen for the study. The right eyes were treated with -10.0 D lenses as the LIM group; the left eyes remained untreated as the control group. The refraction and axial length were measured by streak retinoscopy and A-scan ultrasonography respectively prior to and 4 weeks after the experiment. Four weeks later, the guinea pigs were sacrificed and primary scleral fibroblasts were taken for tissue culture. The 3rd-5th generation scleral fibroblasts were chosen for the experiments. The expression levels of HGF and MMP-2 protein in the scleral fibroblasts were analyzed by Western blotting. After HGF with different doses acted on the scleral fibroblasts of the control group, MMP-2 protein expression in the scleral fibroblasts was analyzed by Western blotting. HGF siRNA was transfected into the scleral fibroblasts of the LIM group and the protein expressions of HGF and MMP-2 were analyzed by Western blotting. RESULTS The LIM group became myopic with a significant increase in axial length (7.97±0.29 mm vs 7.01±0.26 mm, P<0.05), and a significant decrease in refraction (-5.06±0.31 D vs 0.55±0.25 D, P<0.05) compared with the control group. The protein expression of HGF in the scleral fibroblasts of the LIM group was significantly higher compared with the control group ( 1.26±0.04 vs 0.32 ±0.04, P<0.05). The protein expression of MMP-2 in the scleral fibroblasts of the LIM group was significantly higher compared with the control group (0.89±0.06 vs 0.42±0.05, P<0.05). In the scleral fibroblasts of the control group, HGF(0, 0.1, 1, 10 ng/mL) upregulated MMP-2 protein expression in a dose-dependent manner (0.35±0.03, 0.44±0.02, 0.91±0.03, 1.33±0.04, all P<0.05). In the scleral fibroblasts of the LIM group transfected with HGF siRNA, MMP-2 protein expressions were significantly decreased

  3. The changes of ocular axial length and corneal curvatures after scleral buckling for retinal detachment.

    PubMed

    Wang, H Z; Chen, M T; Chang, C H; Tsai, M C; Wu, W C; Chung, C B

    1994-02-01

    As myopia plays an important role in the pathogenesis of retinal detachment, alterations of refractive components after scleral buckling procedures for retinal detachment may be an important factor for retinal redetachment. To find out the refractive change following retinal detachment surgery, we prospectively followed up the alterations of corneal curvature, and axial components (axial length, anterior chamber depth, lens thickness, and vitreous length) of 44 eyes of rhegmatogenous retinal detachment before and after operations. The procedures consisted of encircling scleral buckling (12 eyes) and segmental scleral buckling (32 eyes). All patients were followed for 6 months postoperatively. The corneal curvatures were measured with a keratometer, the axial length and axial components were measured with an A-scan ultrasonography. The methods and materials used in operation were recorded in detail to correlate with the refractive changes. The corneal curvature showed a trend to flatten early after operation (the 1st week), and gradually reversed to steepening. But, the difference was statistically significant only at the K2 (vertical meridian) in the 1st postoperative week and the K1 (horizontal meridian) in the 4th postoperative week. Lengthening of eyeballs were noted in the encircling group (12 eyes), but only the elongation in the 1st postoperative week was statistically significant. While in segmental buckling group, the axial length of the eyeballs was transiently shortened. The shortening was significant in the 2nd, 4th, and 6th week after operation. The reduction of eyeball's axial length was related to the shortening of vitreous length and shallowing of anterior chamber.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Losartan Treatment Protects Retinal Ganglion Cells and Alters Scleral Remodeling in Experimental Glaucoma

    PubMed Central

    Pitha, Ian F.; Nguyen, Cathy; Steinhart, Matthew R.; Nguyen, Thao D.; Pease, Mary Ellen; Oglesby, Ericka N.; Berlinicke, Cynthia A.; Mitchell, Katherine L.; Kim, Jessica; Jefferys, Joan J.

    2015-01-01

    Purpose To determine if oral losartan treatment decreases the retinal ganglion cell (RGC) death caused by experimental intraocular pressure (IOP) elevation in mice. Methods We produced IOP increase in CD1 mice and performed unilateral optic nerve crush. Mice received oral losartan, spironolactone, enalapril, or no drug to test effects of inhibiting angiotensin receptors. IOP was monitored by Tonolab, and blood pressure was monitored by tail cuff device. RGC loss was measured in masked axon counts and RGC bodies by β-tubulin labeling. Scleral changes that could modulate RGC injury were measured including axial length, scleral thickness, and retinal layer thicknesses, pressure-strain behavior in inflation testing, and study of angiotensin receptors and pathways by reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry. Results Losartan treatment prevented significant RGC loss (median loss = 2.5%, p = 0.13), while median loss with water, spironolactone, and enalapril treatments were 26%, 28% and 43%; p < 0.0001). The lower RGC loss with losartan was significantly less than the loss with spironolactone or enalapril (regression model p = 0.001; drug treatment group term p = 0.01). Both losartan and enalapril significantly lowered blood pressure (p< 0.001), but losartan was protective, while enalapril led to worse than water-treated RGC loss. RGC loss after crush injury was unaffected by losartan treatment (difference from control p = 0.9). Survival of RGC in cell culture was not prolonged by sartan treatment. Axonal transport blockade after 3 day IOP elevations was less in losartan-treated than in control glaucoma eyes (p = 0.007). Losartan inhibited effects of glaucoma, including reduction in extracellular signal-related kinase activity and modification of glaucoma-related changes in scleral thickness and creep under controlled IOP. Conclusions The neuroprotective effect of losartan in mouse glaucoma is associated with adaptive changes

  5. Trans-scleral selective laser trabeculoplasty (SLT) without a gonioscopy lens (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Belkin, Michael; Geffen, Noa; Goldenfeld, Modi; Ofir, Shay; Belkin, Avner; Assia, Ehud

    2016-03-01

    Developing a one-second automatic glaucoma treatment using trans-scleral laser trabeculoplasty (LTP) without a gonioscopy lens Purpose: Developing an LTP device for delivering multiple simultaneous trans-scleral applications of low energy laser irradiation to the trabecular meshwork (TM) for reducing Intraocular Pressure (IOP). Methods: Concept proof: A randomized, masked, controlled one was performed on open angle glaucoma patients. The control group underwent conventional SLT (100 laser spots through a gonioscope for 360 degrees directly on the TM). The trial group underwent irradiation by the same laser at the same irradiation parameters on the sclera overlying the TM. Topical glaucoma therapy was not changed during the 12 months trial. Feasibility trial: Using optimized laser parameters, 60 discrete applications were administered on similar locations of patients' sclera. Results: Concept proof: Trans-scleral applications: (N=15), IOP decrease from 20.21 mmHg before treatment to 16.00 (27.1%) at one year. The corresponding numbers for the control group (n=15), were 21.14 mmHg and 14.30 (23.4%). There was no statistical difference between the two groups in IOP reduction. The complications rate was significantly higher in the control group. Trial 2: IOP was reduced from an of 25.3 mmHg to 19.3 (23.7%) in the 11 patients. Conclusions: Laser coherency, lost in tissue transmission, is not required for the therapeutic effect. The new method will possibly enable treatment of angle closure glaucoma as well as simultaneous applications of all laser spots to the sclera. When used conjointly with target acquisition, will make feasible an automatic glaucoma treatment in less than one second.

  6. The tibialis posterior tendon.

    PubMed

    Lhoste-Trouilloud, A

    2012-02-01

    The tibialis posterior tendon is the largest and anteriormost tendon in the medial ankle. It produces plantar flexion and supination of the ankle and stabilizes the plantar vault. Sonographic assessment of this tendon is done with high-frequency, linear-array transducers; an optimal examination requires transverse retromalleolar, longitudinal retromalleolar, and distal longitudinal scans, as well as dynamic studies. Disorders of the posterior tibial tendon include chronic tendinopathy with progressive rupture, tenosynovitis, acute rupture, dislocation and instability, enthesopathies. The most common lesion is a progressive "chewing gum" lesion that develops in a setting of chronic tendinopathy; it is usually seen in overweight women over 50 years of age with valgus flat feet. Medial ankle pain must also be carefully investigated, and the presence of instability assessed with dynamic maneuvers (forced inversion, or dorsiflexion) of the foot. Sonography plays an important role in the investigation of disorders involving the posterior tibial tendon.

  7. Posterior Fossa Tumors.

    PubMed

    Brandão, Lara A; Young Poussaint, Tina

    2017-02-01

    Pediatric brain tumors are the leading cause of death from solid tumors in childhood. The most common posterior fossa tumors in children are medulloblastoma, atypical teratoid/rhabdoid tumor, cerebellar pilocytic astrocytoma, ependymoma, and brainstem glioma. Location, and imaging findings on computed tomography (CT) and conventional MR (cMR) imaging may provide important clues to the most likely diagnosis. Moreover, information obtained from advanced MR imaging techniques increase diagnostic confidence and help distinguish between different histologic tumor types. Here we discuss the most common posterior fossa tumors in children, including typical imaging findings on CT, cMR imaging, and advanced MR imaging studies.

  8. Long-Term Outcome of Medial Rectus Recession and Pulley Posterior Fixation in Esotropia With High AC/A Ratio

    PubMed Central

    Wabulembo, Geoffrey; Demer, Joseph L.

    2014-01-01

    Purpose: Medial rectus (MR) recession with pulley posterior fixation (PF) can be used to treatesotropia (ET) with a high accommodative convergence to accommodation (AC/A) ratio as effectively in the short term as MR recession with scleral PF. This study provides a novel examination of the long-term results of MR recession with pulley PF (PPF). Methods: In 21 children we performed bilateral MR recession and pulley PF for ET greater at near than distance (high AC/A). Mean follow-up was 3.5 ± 2.5 (standard deviation [SD]) years. Results: Mean age at presentation was 2.7 ± 1.8 and at surgery 4.3 ± 1.6 years. Fourteen (67%) children had amblyopia. Distance and near pre-operative ET averaged 19.6Δ ± 10.5Δ and 36.9Δ ± 18.9Δ, respectively. Mean near-distance (N-D) disparity was 16.4Δ ± 12.3Δ. The MR recession averaged 4.4 ± 0.9 mm. Early mean postoperative ET was 1.3 ± 3.3Δ at distance and 2.8Δ ± 5.2Δ at near. Mean late postoperative ET was 0.1Δ ± 5.8Δ and 1.0Δ ± 6.2Δ at distance and near, respectively. At the final postoperative examination, mean N-D disparity was reduced to 0.9Δ ± 3.6Δ. Discussion: MR recession with PPF has a high long-term effectiveness, even in patients with amblyopia and autism. Since no posterior scleral suturing is required, it minimizes the perforation risk associated with scleral PF. Conclusion: MR recession with PPF is a safe and highly effective long-term treatment for ET with high AC/A ratio. Long-term results may surpass those of alternate procedures. PMID:22906381

  9. Tibialis Posterior Tendon Entrapment Within Posterior Malleolar Fracture Fragment.

    PubMed

    Fantry, Amanda; Lareau, Craig; Vopat, Bryan; Blankenhorn, Brad

    2016-01-01

    Management of posterior malleolus fractures continues to be controversial, with respect to both need for fixation and fixation methods. Fixation methods include an open posterior approach to the ankle as well as percutaneous reduction and fixation with or without arthroscopy for visualization of the articular surface. Plain radiographs are unreliable in identifying fracture pattern and intraoperative reduction, making arthroscopy a valuable adjunct to posterior malleolus fracture management. In this article, we report a case of tibialis posterior tendon entrapment within a posterior malleolus fracture, as identified by arthroscopy and managed with open reduction. Tibialis posterior tendon entrapment within a posterior malleolus has not been previously reported. Ankle arthroscopy for posterior malleolus fractures provides an opportunity to identify soft-tissue or tendinous entrapment, articular surface reduction, and articular cartilage injuries unlikely to be identified with fluoroscopy alone and should be considered in reduction and fixation of posterior malleolus fractures.

  10. Analysis of Scleral Feeder Vessel in Myopic Choroidal Neovascularization Using Optical Coherence Tomography Angiography

    PubMed Central

    Louzada, Ricardo Noguera; Ferrara, Daniela; Novais, Eduardo Amorim; Moult, Eric; Cole, Emily; Lane, Mark; Fujimoto, James; Duker, Jay S.; Baumal, Caroline R.

    2017-01-01

    To describe the appearance of a scleral-derived feeder vessel in a highly myopic eye with secondary choroidal neovascularization (CNV) as visualized on both en face high-speed swept-source (SS) optical coherence tomography angiography (OCTA) prototype, and a commercially available spectral-domain (SD) OCTA, with the corresponding en face and cross-sectional structural OCT images. In this case report, a 60-year-old white male presented with high myopia and secondary CNV in the right eye, previously treated with anti-vascular endothelial growth factor, and was imaged on both SD-OCT and SS-OCT. The neovascular complex could be visualized on both devices. Structural en face SS-OCT images demonstrated a large choroidalscleral feeder vessel that was not visualized with SD-OCT. The authors concluded that structural en face SS-OCT better visualizes scleral feeder vessel compared to SD-OCT due to the longer wavelength (~1,050 nm) with increased choroidal penetration and decreased sensitivity roll-off in the SS-OCT system. PMID:27759864

  11. Transmuscular Migration of a Scleral Tunnel-Secured Encircling Silicone Band

    PubMed Central

    Nishida, Yui; Fukumoto, Masanori; Kida, Teruyo; Suzuki, Hiroyuki; Ikeda, Tsunehiko

    2016-01-01

    The migration of an encircling silicone band through a rectus muscle is a rare postoperative complication associated with scleral buckling surgery for retinal detachment. In this present study, we describe what we believe to be the first reported case of a patient who experienced postoperative migration of an encircling silicone band through the rectus muscle, despite the band being surgically secured to the sclera in a scleral tunnel. A 58-year-old man presented with a rhegmatogenous retinal detachment in his left eye. Pars plana vitrectomy was performed with the placement of an encircling silicone band, and the patient's retina was successfully reattached. One year postoperatively, the encircling band became exposed on the nasal side of the conjunctiva next to the limbus without any symptoms. Two weeks later, the exposed encircling band was surgically removed without any complications. The findings of this study show that even when an encircling silicone band is surgically secured around the eye, periodic and careful postoperative follow-up examinations should be performed to ensure no migration of the band. PMID:27790129

  12. Scleral Cross-linking Using Riboflavin and Ultraviolet-A Radiation for Prevention of Axial Myopia in a Rabbit Model.

    PubMed

    Dotan, Assaf; Kremer, Israel; Gal-Or, Orly; Livnat, Tami; Zigler, Arie; Bourla, Dan; Weinberger, Dov

    2016-04-03

    Myopic individuals, especially those with severe myopia, are at higher-than-normal risk of cataract, glaucoma, retinal detachment and chorioretinal abnormalities. In addition, pathological myopia is a common irreversible cause of visual impairment and blindness. Our study demonstrates the effect of scleral crosslinking using riboflavin and ultraviolet-A radiation on the development of axial myopia in a rabbit model. The axial length of the eyeball was measured by A-scan ultrasound in New Zealand white rabbits aged 13 days (male and female). The eye then underwent 360° conjunctival peritomy with scleral crosslinking, followed by tarsorrhaphy. Axial elongation was induced in 13 day-old New Zealand rabbits by suturing their right eye eyelids (tarsorrhaphy). The eyes were divided into quadrants, and every quadrant had two scleral irradiation zones, each with an area of 0.2 cm² and a radius of 4 mm. Crosslinking was performed by dropping 0.1% dextran-free riboflavin-5-phosphate onto the irradiation zones 20 sec before ultraviolet-A irradiation and every 20 sec during the 200 sec irradiation time. UVA radiation (370 nm) was applied perpendicular to the sclera at 57 mW/cm² (total UVA light dose, 57 J/cm²). Tarsorrhaphies were removed on day 55, followed by repeated axial length measurements. This study demonstrates that scleral crosslinking with riboflavin and ultraviolet-A radiation effectively prevents occlusion-induced axial elongation in a rabbit model.

  13. Posterior Circulation Ischemic Stroke.

    PubMed

    Go, Steven

    2015-01-01

    Approximately 20-25% of all acute strokes occur in the posterior circulation. These strokes can be rather difficult to diagnose because they present in such diverse ways, and can easily be mistaken for more benign entities. A fastidious history, physical exam, high clinical suspicion, and appropriate use of imaging are essential for the emergency physician to properly diagnose and treat these patients. Expert stroke neurologist consultation should be utilized liberally.

  14. Posterior scleritis presenting as conjunctivitis in a child.

    PubMed

    Mallick, Jyotiranjan; Pujahari, Susant; Maharana, Prafulla Kumar

    2016-12-09

    A 14-year-old male child presented with redness and decreased vision in the right eye for 7 days. He was being treated for viral conjunctivitis for right eye at a local hospital. His visual acuity was 6/24 OD and 6/9 OS. Slit-lamp examination revealed diffuse conjunctival congestion in the right eye. Dilated fundus examination revealed mild disc hyperaemia and retinal striae in both the eyes. A peripapillary serous detachment of macula in the right eye was seen on optical coherence tomography. B scan ultrasonography revealed increased scleral thickening and characteristic 'T' sign in both the eyes. Investigations revealed no other relevant systemic association. A diagnosis of bilateral posterior scleritis was made. The patient was started on topical steroids and oral non-steroidal anti-inflammatory drugs. Within 2 weeks of therapy the visual acuity improved to 6/6, the serous detachment resolved and retinal striae reduced in both the eyes.

  15. Planned posterior assisted levitation in severe subluxated cataract: surgical technique and clinical results.

    PubMed

    Lifshitz, Tova; Levy, Jaime; Kratz, Assaf; Belfair, Nadav; Tsumi, Erez

    2012-01-01

    We report the surgical technique and outcome of planned posterior assisted levitation (P-PAL) in four cases of subluxated cataract. P-PAL was planned as the preferred approach in all cases. A spatula was inserted via the pars plana, the whole lens was lifted to the anterior chamber and then removed through a scleral tunnel incision. Anterior chamber intraocular lenses were implanted in all cases. All four eyes had severe subluxation of the crystalline lenses with marked phacodonesis. Two eyes had history of blunt trauma, and the other two eyes had severe pseudoexfoliation with spontaneous lens subluxation. Follow-up ranged from 1 to 2 years in three cases. The postoperative visual acuity was 20/80 or better. No intraoperative complications were observed. In conclusion, the P-PAL technique was successfully performed during cataract surgery in four eyes with severe subluxated cataracts. There were no complications over the long-term follow-up.

  16. Posterior dislocation of the shoulder in athletes.

    PubMed

    Samilson, R L; Prieto, V

    1983-07-01

    Although posterior dislocation of the shoulder is a rare injury in athletes, failure to recognize and properly manage acute dislocation may have serious consequences. The article discusses the incidence, mechanism of injury, classification, pathologic findings, clinical and radiologic diagnosis, and management.

  17. Scleral buckling with a noncontact wide-angle viewing system in the management of retinal detachment with undetected retinal break: a case report

    PubMed Central

    Kita, Mihori; Fujii, Yukiko; Kawagoe, Naoaki; Hama, Sachiyo

    2013-01-01

    A young patient who showed rhegmatogenous retinal detachment with preoperatively undetected retinal break was successfully treated by scleral buckling using a noncontact wide-angle viewing system. PMID:23569352

  18. The effect of scleral search coil lens wear on the eye

    PubMed Central

    Murphy, P.; Duncan, A.; Glennie, A.; Knox, P.

    2001-01-01

    BACKGROUND/AIM—Scleral search coils are used to measure eye movements. A recent abstract suggests that the coil can affect the eye by decreasing visual acuity, increasing intraocular pressure, and damaging the corneal and conjunctival surface. Such findings, if repeated in all subjects, would cast doubt on the credibility of the search coil as a reliable investigative technique. The aim of this study was to reassess the effect of the scleral search coil on visual function.
METHODS—Six volunteer subjects were selected to undergo coil wear and baseline measurements were taken of logMAR visual acuity, non-contact tonometry, keratometry, and slit lamp examination. Four drops of 0.4% benoxinate hydrochloride were instilled before insertion of the lens by an experienced clinician. The lens then remained on the eye for 30 minutes. Measurements of the four ocular health parameters were repeated after 15 and 30 minutes of lens wear. The lens was then removed and the health of the eye reassessed.
RESULTS—No obvious pattern of change was found in logMAR visual acuity, keratometry, or intraocular pressure. The lens did produce changes to the conjunctival and corneal surfaces, but this was not considered clinically significant.
CONCLUSION—Search coils do not appear to cause any significant effects on visual function. However, thorough prescreening of subjects and post-wear checks should be carried out on all coil wearers to ensure no adverse effects have been caused.

 PMID:11222341

  19. Scleral buckling for retinal detachment in Ibadan, Sub-Saharan Africa: anatomical and visual outcome

    PubMed Central

    Oluleye, TS; Ibrahim, OA; Olusanya, BA

    2013-01-01

    Background Scleral buckle surgery is not a commonly performed surgical procedure in Sub-Saharan Africa due to a paucity of trained vitreo retinal surgeons. The aim of the study was to review sclera buckle procedures with a view to evaluating the anatomical and visual outcomes. Methods Case records of patients that had scleral buckle surgery at the Retina Unit of the University College Hospital, Ibadan, Nigeria, between 2007 and 2010 were reviewed. Information retrieved included patients’ demographics, duration of symptoms, and presenting vision. Other information included site of retinal break, extent of retinal detachment, involvement of the fellow eye, and macular involvement. Postoperative retina reattachment and postoperative visual acuity were also recorded. Proportions and percentages were used to analyze data. Results Forty five eyes of 42 patients were studied with a male to female ratio of 1.6:1. The mean age was 47.7 years (±17.6 years). The median duration before presentation was 3 months (range: 5 days – 156 months). Subtotal retinal detachment was found in 35 eyes (77.8%) while total retinal detachment occurred in ten eyes (22.2%). Thirty four eyes (75.6%) had “macular off ” detachments. At 6 weeks, there was an improvement in visual acuity in 23 eyes (51.1%), while visual acuity remained the same in nine eyes (20%) and was worse in 13 eyes (28.9%). Anatomical attachment was seen in 43 eyes (95.6%) on the operation table, in 40 eyes (90.9%) at first day postoperatively and in 32 eyes (86.5%) at 6 weeks after surgery. Conclusion Outcome of sclera buckle surgery for rhegmatogenous retinal detachment may be improved in developing countries of Sub Sahara Africa if adequate awareness is created to educate the populace on early presentation. PMID:23754869

  20. Current applications and efficacy of scleral contact lenses — a retrospective study

    PubMed Central

    Severinsky, Boris; Millodot, Michel

    2010-01-01

    Purpose To evaluate the indications and efficacy of high gas permeable scleral contact lenses (GP-SCL). Methods A total database of 97 consecutive patients (140 eyes) fitted with GP-SCL between January 2003 and December 2008, was retrospectively analyzed to determine the benefits of fitting scleral lenses. All lenses were fitted by preformed technique and were non-fenestrated. Patients included keratoconus – 88 eyes (63 %); corneal irregularities after penetrating keratoplasty – 39 eyes (28 %); various ocular surface disorders: Stevens-Johnson syndrome (SJS), graft versus host disease (GVHD) and exposure keratopathy – 6 eyes (4 %); post refractive surgery keratoectasia – 4 eyes (3 %), and high refractive error – 3 eyes (2 %). Results Mean follow up was 27.5 months (range 1–71), mean wearing time in successful wearers group was 12.2 hours per day (range 10–16), mean wearing time in group of wearers who dropped out using GP-SCL, was 5.8 hours (range 3–8). Keratoconus patients achieved median best corrected visual acuity (BCVA) of 20/32, 84 % of patients achieved BCVA of 20/40 or more. The post keratoplasty group achieved median BCVA of 20/25, 92 % of patients achieved BCVA of 20/40 or better. In the other groups, median BCVA was as follows: ocular surface disorders – 20/50, keratoectasia – 20/30, high refractive error – 20/32. Positive fluid-venting was highly associated with successful GP-SCL wearing. Twenty patients (21 %) failed to wear GP-SCL. Conclusions GP-SCL's expand the management of various corneal abnormalities. The main indication for GP-SCL is optical correction of an irregular corneal surface, especially keratoconus and corneal transplant.

  1. Posterior interosseous neuropathy

    PubMed Central

    Kele, Henrich; Xia, Annie; Weiler, Markus; Schwarz, Daniel; Bendszus, Martin; Pham, Mirko

    2016-01-01

    Objective: To investigate the spatial pattern of lesion dispersion in posterior interosseous neuropathy syndrome (PINS) by high-resolution magnetic resonance neurography. Methods: This prospective study was approved by the local ethics committee and written informed consent was obtained from all patients. In 19 patients with PINS and 20 healthy controls, a standardized magnetic resonance neurography protocol at 3-tesla was performed with coverage of the upper arm and elbow (T2-weighted fat-saturated: echo time/repetition time 52/7,020 milliseconds, in-plane resolution 0.27 × 0.27 mm2). Lesion classification of the radial nerve trunk and its deep branch (which becomes the posterior interosseous nerve) was performed by visual rating and additional quantitative analysis of normalized T2 signal of radial nerve voxels. Results: Of 19 patients with PINS, only 3 (16%) had a focal neuropathy at the entry of the radial nerve deep branch into the supinator muscle at elbow/forearm level. The other 16 (84%) had proximal radial nerve lesions at the upper arm level with a predominant lesion focus 8.3 ± 4.6 cm proximal to the humeroradial joint. Most of these lesions (75%) followed a specific somatotopic pattern, involving only those fascicles that would form the posterior interosseous nerve more distally. Conclusions: PINS is not necessarily caused by focal compression at the supinator muscle but is instead frequently a consequence of partial fascicular lesions of the radial nerve trunk at the upper arm level. Neuroimaging should be considered as a complementary diagnostic method in PINS. PMID:27683851

  2. Posterior Urethral Strictures

    PubMed Central

    Gelman, Joel; Wisenbaugh, Eric S.

    2015-01-01

    Pelvic fracture urethral injuries are typically partial and more often complete disruptions of the most proximal bulbar and distal membranous urethra. Emergency management includes suprapubic tube placement. Subsequent primary realignment to place a urethral catheter remains a controversial topic, but what is not controversial is that when there is the development of a stricture (which is usually obliterative with a distraction defect) after suprapubic tube placement or urethral catheter removal, the standard of care is delayed urethral reconstruction with excision and primary anastomosis. This paper reviews the management of patients who suffer pelvic fracture urethral injuries and the techniques of preoperative urethral imaging and subsequent posterior urethroplasty. PMID:26691883

  3. Symptomatic posterior mediastinal angioleiomyoma.

    PubMed

    I, Hoseok; Jeong, Yeon Joo; Choi, Kyung Un; Kim, Yeong-Dae

    2008-08-30

    We report a case of a symptomatic angioleiomyoma in the left posterior mediastinum. A 66-year-old woman presented with left back and flank pain for 6 months. Chest computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-circumscribed 4.3 cm round mass. The mass was initially diagnosed as nerve sheath tumor, because of her symptoms and its close location to the sympathetic trunk and intercostal nerve. It was uneventfully removed through video-assisted thoracoscopic surgery. The pathology revealed an angioleiomyoma.

  4. Posterior Cortical Atrophy

    PubMed Central

    Crutch, Sebastian J; Lehmann, Manja; Schott, Jonathan M; Rabinovici, Gil D; Rossor, Martin N; Fox, Nick C

    2013-01-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that is characterized by a progressive decline in visuospatial, visuoperceptual, literacy and praxic skills. The progressive neurodegeneration affecting parietal, occipital and occipito-temporal cortices which underlies PCA is attributable to Alzheimer's disease (AD) in the majority of patients. However, alternative underlying aetiologies including Dementia with Lewy Bodies (DLB), corticobasal degeneration (CBD) and prion disease have also been identified, and not all PCA patients have atrophy on clinical imaging. This heterogeneity has led to diagnostic and terminological inconsistencies, caused difficulty comparing studies from different centres, and limited the generalizability of clinical trials and investigations of factors driving phenotypic variability. Significant challenges remain in identifying the factors associated with both the selective vulnerability of posterior cortical regions and the young age of onset seen in PCA. Greater awareness of the syndrome and agreement over the correspondence between syndrome-and disease-level classifications are required in order to improve diagnostic accuracy, research study design and clinical management. PMID:22265212

  5. Posterior Fossa Meningioma

    PubMed Central

    Saleh, Essam A.; Taibah, Abdel Kader; Achilli, Vittorio; Aristegui, Miguel; Mazzoni, Antonio; Sanna, Mario

    1994-01-01

    Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far. ImagesFigure 1Figure 2Figure 3Figure 4p206-bFigure 5p207-bFigure 5 PMID:17171173

  6. Development of a murine ocular posterior segment explant culture for the study of intravitreous vector delivery.

    PubMed

    Denk, Nora; Misra, Vikram; Sandmeyer, Lynne S; Bauer, Bianca B; Singh, Jaswant; Forsyth, George W; Grahn, Bruce H

    2015-01-01

    The objective of this study was to develop a murine retinal/choroidal/scleral explant culture system to facilitate the intravitreous delivery of vectors. Posterior segment explants from adult mice of 2 different age groups (4 wk and 15 wk) were cultured in serum-free medium for variable time periods. Tissue viability was assessed by gross morphology, cell survival quantification, activated caspase-3 expression, and immunohistochemistry. To model ocular gene therapy, explants were exposed to varying transducing units of a lentiviral vector expressing the gene for green fluorescent protein for 48 h. Explant retinal cells remained viable for approximately 1 wk, although the ganglion cell layer developed apoptosis between 4 and 7 d. Following vector infusion into the posterior segment cups, viral transduction was noted in multiple retinal layers in both age groups. An age of donor mouse influence was noted and older mice did not transduce as well as younger mice. This explant offers an easily managed posterior segment ocular culture with minimum disturbance of the tissue, and may be useful for investigating methods of enhancing retinal gene therapy under controlled conditions.

  7. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region

    PubMed Central

    Sureda-Gómez, Miquel; Pascual-Carreras, Eudald; Adell, Teresa

    2015-01-01

    The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior) axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts) are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent) underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis. PMID:26556349

  8. Bilateral Implantation of Scleral-Fixated Cionni Endocapsular Rings and Toric Intraocular Lenses in a Pediatric Patient with Marfan's Syndrome

    PubMed Central

    Gimbel, Howard V.; Camoriano, Gerardo D.; Aman-Ullah, Muhammad

    2012-01-01

    The management of ectopia lentis in Marfan's syndrome is challenging. Multiple disease-associated factors conspire to deprive these patients of adequate vision. While optical correction with glasses and contact lenses is usually advocated early on, the irregular astigmatism and even partial aphakia that accompanies advanced cases generally warrant surgical intervention. Several surgical strategies have been devised to manage these challenging cases, including the combination of endocapsular or pars plana lensectomy and iris or scleral fixation of the intraocular lens (IOL) or IOL-bag complex. All of the reported cases have been implanted with IOLs that correct for myopia only. With toric lenses, it is now possible to correct for corneal astigmatism in these patients as well, provided that the capsular bag is maintained and can be properly centered. We report the combination of scleral-fixated Cionni endocapsular rings and toric IOLs in a pediatric patient with bilateral ectopia lentis secondary to Marfan's syndrome. PMID:22615696

  9. BAER suppression during posterior fossa dural opening

    PubMed Central

    Shields, Christopher B.; Shields, Lisa B. E.; Jiang, Yi Dan; Yao, Tom; Zhang, Yi Ping; Sun, David A.

    2015-01-01

    Background: Intraoperative monitoring with brainstem auditory evoked responses (BAER) provides an early warning signal of potential neurological injury and may avert tissue damage to the auditory pathway or brainstem. Unexplained loss of the BAER signal in the operating room may present a dilemma to the neurosurgeon. Methods: This paper documents two patients who displayed a unique mechanism of suppression of the BAER apparent within minutes following dural opening for resection of a posterior fossa meningioma. Results: In two patients with anterior cerebellopontine angle and clival meningiomas, there was a significant deterioration of the BAER soon after durotomy but prior to cerebellar retraction and tumor removal. Intracranial structures in the posterior fossa lying between the tumor and dural opening were shifted posteriorly after durotomy. Conclusion: We hypothesized that the cochlear nerve and vessels entering the acoustic meatus were compressed or stretched when subjected to tissue shift. This movement caused cochlear nerve dysfunction that resulted in BAER suppression. BAER was partially restored after the tumor was decompressed, dura repaired, and bone replaced. BAER was not suppressed following durotomy for removal of a meningioma lying posterior to the cochlear complex. Insight into the mechanisms of durotomy-induced BAER inhibition would allay the neurosurgeon's anxiety during the operation. PMID:25883849

  10. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

    The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

  11. Posterior pole tumor update.

    PubMed

    Ou, Judy I; Wheeler, Sharon M; O'Brien, Joan M

    2002-12-01

    This chapter focuses on the diagnosis and management of choroidal melanoma in light of recent findings from the COMS. Retinoblastoma is emphasized to describe recent trends in primary treatment away from EBRT and toward chemoreduction with local therapy. In addition, vascular and glial tumors of the retina and tumors of the retinal pigment epithelium are described because of the association between these lesions and systemic disease. Recent advances in treatment and genetic testing for these diseases are discussed. Finally, ocular metastasis, intraocular lymphoid tumors, and intraocular leukemia are included because of their importance in determining systemic treatment and prognosis. The chapter gives an overview of important posterior pole tumors and highlights recent developments in the management of each intraocular disease process.

  12. Scleral lenses for severe chronic GvHD-related keratoconjunctivitis sicca: a retrospective study by the SFGM-TC.

    PubMed

    Magro, L; Gauthier, J; Richet, M; Robin, M; Nguyen, S; Suarez, F; Dalle, J-H; Fagot, T; Huynh, A; Rubio, M-T; Oumadely, R; Vigouroux, S; Milpied, N; Delcampe, A; Yakoub-Agha, I

    2017-02-20

    Chronic GvHD-related keratoconjunctivitis sicca (cGvHD-related KCS) can significantly alter the quality of life of patients after allogeneic hematopoietic stem cell transplantation. The aim of this work was to assess the efficacy and tolerability of scleral lenses to treat severe cGvHD-related KCS. In this retrospective, multicenter study, we included 60 consecutive patients diagnosed with cGvHD-related KCS and fitted with scleral lenses. Patients were evaluated at baseline and at 2 months with the following tests: the Ocular Surface Disease Index (OSDI) to assess quality of life, the Oxford score to grade corneal damage and the logarithm of minimal angle of resolution (Log MAR) scale to determine visual acuity. We observed improvement in quality of life in 58 patients (97%). All parameters improved at 2 months. We observed significant differences at 2 months compared with baseline for the mean OSDI (86 versus 30, respectively, P<0.001), the mean Oxford score (3.2 versus 1.3, respectively, P<0.001) as well as visual acuity (Log MAR of 0.33 versus 0.10, respectively, P<0.001). Treatment with scleral lenses was discontinued in only 5 patients (8%) with a median follow-up of 20.5 months (range: 2-125 months). Scleral lenses were very efficient and well tolerated in patients with severe cGvHD-related KCS.Bone Marrow Transplantation advance online publication, 20 February 2017; doi:10.1038/bmt.2017.9.

  13. Femtosecond laser subsurface scleral treatment in cadaver human sclera and evaluation using two-photon and confocal microscopy

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Fan, Zhongwei; Yan, Ying; Lian, Fuqiang; Kurtz, Ron; Juhasz, Tibor

    2016-03-01

    Glaucoma is the second-leading cause of blindness worldwide and is often associated with elevated intraocular pressure (IOP). Partial-thickness drainage channels can be created with femtosecond laser in the translucent sclera for the potential treatment of glaucoma. We demonstrate the creation of partial-thickness subsurface drainage channels with the femtosecond laser in the cadaver human eyeballs and describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in cadaver human eyes. A femtosecond laser operating at a wavelength of 1700 nm was scanned along a rectangular raster pattern to create the partial thickness subsurface drainage channels in the sclera of cadaver human eyes. Analysis of the dimensions and location of these channels is important in understanding their effects. We describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in cadaver human eyes. High-resolution images, hundreds of microns deep in the sclera, were obtained to allow determination of the shape and dimension of such partial thickness subsurface scleral channels. Our studies suggest that the confocal and two-photon microscopy can be used to investigate femtosecond-laser created partial-thickness drainage channels in the sclera of cadaver human eyes.

  14. Posterior Reversible Encephalopathy Syndrome

    PubMed Central

    Algahtani, Abdulhadi; Aldarmahi, Ahmad; Hmoud, Mohammed; Marzuk, Yousef; Shirah, Bader

    2016-01-01

    Objectives: Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological syndrome characterized by headache, altered mental status, seizures, or loss of vision. In this study, we report the largest series of PRES coming from Saudi Arabia and explore the etiology, clinical presentation, and outcome. We also report new imaging findings associated with this condition. Methods: We performed a retrospective study of all cases of PRES admitted to King Abdulaziz Medical City, Jeddah, Saudi Arabia, between the years 2005 and 2015. A neurologist reviewed all charts and analyzed the clinical presentations, etiological factors, and outcomes, and a neuroradiologist reviewed the imaging studies. Only patients with clinical and imaging features consistent with PRES were included in the study. Results: We collected 31 patients who had clinical and radiological features consistent with PRES. Females were more affected than males (18 females and 13 males), and patients’ age ranged from 6 to 95 years, with a mean of 38.3 years. Patients were treated by removing the precipitating causes and treating the underlying conditions. Resolution of neurologic signs occurred within 2 to 3 weeks in all patients. Conclusion: In our opinion, PRES itself is usually a benign condition with complete recovery if the condition is recognized early and managed appropriately. Although clinical signs are nonspecific, the constellation of symptoms including headache, visual problems, seizures, and altered level of consciousness should suggest the possibility of PRES, especially in high-risk group. Abnormalities on magnetic resonance imaging are often characteristic and may be the first clue to the diagnosis. PMID:28042366

  15. Human ocular torsion during parabolic flights: an analysis with scleral search coil

    NASA Technical Reports Server (NTRS)

    Cheung, B. S.; Money, K.; Howard, I.; Kirienko, N.; Johnson, W.; Lackner, J.; Dizio, P.; Evanoff, J.

    1992-01-01

    Rotation of the eyes about the visual axis is known as ocular torsion. A lateral inclination (a "roll") of the head induces ocular torsion in the opposite direction, a response known as ocular counterrolling. For six subjects, we recorded the static (head still) and dynamic (head in oscillatory roll motion) ocular torsion in normal 1 g condition and also during the microgravity and hypergravity periods of parabolic flight, using the electromagnetic scleral search coil technique. With the head still, the direction and magnitude of torsion that occurred in response to microgravity and hypergravity differed substantially from one individual to another, but there was a significant difference in torsional magnitude between the microgravity and hypergravity periods, for all static head positions including the upright position. Under normal 1 g conditions, counterrolling compensated for about 16% of (voluntary) static head roll, while dynamic counterroll was much larger, up to 36% of head roll at 0.55 Hz. With increasing frequency of head oscillation between 0.33 Hz and 0.55 Hz, the gain of counterrolling increased and there was no change in the phase relationship. The gain of dynamic counterroll (in response to voluntary head rolling) was not significantly less in hypogravity, suggesting that on the ground at these frequencies the contribution of gravity and gravity receptors to this reflex is redundant: this reflex is probably driven by the semicircular canals. In some subjects, the torsional displacement in microgravity is accompanied by micro-torsional oscillatory motion.

  16. A novel and inexpensive digital system for eye movement recordings using magnetic scleral search coils.

    PubMed

    Eibenberger, Karin; Eibenberger, Bernhard; Roberts, Dale C; Haslwanter, Thomas; Carey, John P

    2016-03-01

    After their introduction by Robinson (IEEE Trans Biomed Eng 10:137-145, 1963), magnetic scleral search coils quickly became an accepted standard for precise eye movement recordings. While other techniques such as video-oculography or electro-oculography may be more suitable for routine applications, search coils still provide the best low-noise and low-drift characteristics paired with the highest temporal and spatial resolution. The problem with search coils is that many research laboratories still have their large and expensive coil systems installed and are acquiring eye movement data with old, analog technology. Typically, the number of recording channels is limited and modifications to an existing search coil system can be difficult. We propose a system that allows to retro-fit an existing analog search coil system to become a digital recording system. The system includes digital data acquisition boards and a reference coil as the hardware part, receiver software, and a new calibration method. The circuit design has been kept simple and robust, and the proposed software calibration allows the calibration of a single coil within a few seconds.

  17. In vivo volumetric imaging of the human corneo-scleral limbus with spectral domain OCT

    PubMed Central

    Bizheva, Kostadinka; Hutchings, Natalie; Sorbara, Luigina; Moayed, Alireza A.; Simpson, Trefford

    2011-01-01

    The limbus is the structurally rich transitional region of tissue between the cornea on one side, and the sclera and conjunctiva on the other. This zone, among other things, contains nerves passing to the cornea, blood and lymph vasculature for oxygen and nutrient delivery and for waste, CO2 removal and drainage of the aqueous humour. In addition, the limbus contains stem cells responsible for the existence and healing of the corneal epithelium. Here we present 3D images of the healthy human limbus, acquired in vivo with a spectral domain optical coherence tomography system operating at 1060nm. Cross-sectional and volumetric images were acquired from temporal and nasal locations in the human limbus with ~3µm x 18µm (axial x lateral) resolution in biological tissue at the rate of 92,000 A-scans/s. The imaging enabled detailed mapping of the corneo-scleral tissue morphology, and visualization of structural details such as the Vogt palisades, the blood and lymph vasculature including the Schlemm’s canal and the trabecular meshwork, as well as corneal nerve fiber bundles. Non-invasive, volumetric, high resolution imaging reveals fine details of the normal human limbal structure, and promises to provide invaluable information about its changes in health and disease as well as during and after corneal surgery. PMID:21750758

  18. Foveal Structure in Macula-off Rhegmatogenous Retinal Detachment after Scleral Buckling or Vitrectomy

    PubMed Central

    Roohipoor, Ramak; Mohammadi, Naseh; Ghassemi, Fariba; Karkhaneh, Reza; Rezaei, Mansour; Nili-Ahmadabadi, Mehdi; Ebrahimiadib, Nazanin

    2015-01-01

    Purpose: To evaluate foveal microstructural changes and to determine its association with visual outcomes after reattachment of rhegmatogenous retinal detachments (RRDs) by scleral buckling (SB) or pars plana vitrectomy (PPV). Methods: Using spectral domain optical coherence tomography (SD-OCT), foveal microstructure in eyes with macula-off RRD were studied 1, 3, 6, 9, 12 and 15 months after PPV or SB and correlated with visual outcomes. Results: Forty-two eyes were included in the final analysis. Even with improved microstructural changes and normalization of retinal structures on OCT, final visual acuity was not correlated with microstructural changes in eyes undergoing PPV. In the SB group, final visual acuity was significantly correlated with an intact inner segment/outer segment (IS/OS) junction (P = 0.013). There was no significant correlation between final visual acuity and presence of subretinal fluid (SRF) in either group. Conclusion: After SB, eyes with an intact IS/OS junction had better final visual acuity. In the PPV group, there was no significant correlation between microstructural changes and visual acuity. The presence of SRF did not influence final visual acuity in both groups. PMID:26425321

  19. Simultaneous occlusion of three cilioretinal arteries following scleral buckling surgery under local anesthesia

    PubMed Central

    Napoli, Pietro Emanuele; Cuccu, Alberto; Farci, Roberta; Fossarello, Maurizio

    2016-01-01

    Background Cilioretinal artery (CRA) occlusions are rare in young patients. In these cases, the most commonly associated causes are considered to be the same as those implicated in central retina artery occlusions, such as vasculitic processes, migraine, cardiac disorder, and coagulation abnormality. The aim of this article was to report for the first time the medical records and investigational results of an unusual case of simultaneous occlusion of three CRAs after scleral buckling surgery under local anesthesia. Methods A complete ophthalmic examination, including color fundus image, fundus fluorescein angiography, optical coherence tomography, visual field, as well as systemic and laboratory assessments, was performed. Results A case of contemporaneous blockage of three CRAs after ab externo surgery for retinal detachment in a 29-year-old Caucasian woman was reported. The interdisciplinary approach and the imaging results have allowed us the clinical definition of such a very rare case. Conclusion Here, we reported that optical coherence tomography is an indispensable tool to better delineate the pathological process and follow atrophic changes in the macula, especially in cases in which fundus fluorescein angiography and systemic tests may be poorly informative. PMID:27695367

  20. Posterior sampling with improved efficiency

    SciTech Connect

    Hanson, K.M.; Cunningham, G.S.

    1998-12-01

    The Markov Chain Monte Carlo (MCMC) technique provides a means to generate a random sequence of model realizations that sample the posterior probability distribution of a Bayesian analysis. That sequence may be used to make inferences about the model uncertainties that derive from measurement uncertainties. This paper presents an approach to improving the efficiency of the Metropolis approach to MCMC by incorporating an approximation to the covariance matrix of the posterior distribution. The covariance matrix is approximated using the update formula from the BFGS quasi-Newton optimization algorithm. Examples are given for uncorrelated and correlated multidimensional Gaussian posterior distributions.

  1. Biomechanics of the Human Posterior Sclera: Age- and Glaucoma-Related Changes Measured Using Inflation Testing

    PubMed Central

    Coudrillier, Baptiste; Tian, Jing; Alexander, Stephen; Myers, Kristin M.; Quigley, Harry A.; Nguyen, Thao D.

    2012-01-01

    Purpose. The objective of this study was to measure the biomechanical response of the human posterior sclera in vitro and to estimate the effects of age and glaucoma. Methods. Scleral specimens from 22 donors with no history of glaucoma and 11 donors with a history of glaucoma were excised 3 mm posterior to the equator and affixed to an inflation chamber. Optic nerve cross-sections were graded to determine the presence of axon loss. The time-dependent inflation response was measured in a series of pressure-controlled load–unload tests to 30 mm Hg and creep tests to 15 and 30 mm Hg. Circumferential and meridional strains were computed from the digital image correlation displacements, and midposterior stresses were determined from pressure and deformed geometry. Results. Among normal specimens, older age was predictive of a stiffer response and a thinner sclera. In the age group 75 to 93, diagnosed glaucoma eyes with axon damage were thicker than normal eyes. Both damaged and undamaged glaucoma eyes had a different strain response in the peripapillary sclera characterized by a stiffer meridional response. Undamaged glaucoma eyes had slower circumferential creep rates in the peripapillary sclera than normal eyes. Glaucoma eyes were not different from normal eyes in stresses and strains in the midposterior sclera. Conclusions. The observed differences in the biomechanical response of normal and glaucoma sclera may represent baseline properties that contribute to axon damage, or may be characteristics that result from glaucomatous disease. PMID:22395883

  2. Mini-scleral Contact Lens for Management of Poor Visual Outcomes after Intrastromal Corneal Ring Segments Implantation in Keratoconus

    PubMed Central

    Alipour, Fatemeh; Rahimi, Firoozeh; Hashemian, Mohammad Naser; Ajdarkosh, Zahra; Roohipoor, Ramak; Mohebi, Masoumeh

    2016-01-01

    Purpose: To evaluate the feasibility and efficacy of mini-scleral design (MSD) contact lenses to treat keratoconus patients who were unsatisfied with the results of corneal inlay. Methods: In this prospective interventional case series, 9 eyes of 6 keratoconus patients who were unsatisfied with the results of corneal inlay were fitted with MSD contact lenses. Demographic data, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and higher order aberrations (HOAs) were evaluated before contact lens fitting. Corrected visual acuity by placing the MSD contact lens with or without over-refraction, and HOAs were measured one hour after contact lens fitting. One month after contact lens wearing, corrected visual acuity by placing the MSD contact lens with over-refraction and possible contact lens related problems were assessed. Ocular comfort and contact lens handling problems were asked in follow-up visits. The data was analyzed using descriptive statistical tests. Results: Nine eyes of 6 patients were successfully fitted with the mini-scleral lens. Fitting was ideal in 7 eyes and acceptable in 2 eyes. Mean corrected visual acuity by placing the MSD lens without over-refraction was 0.09 (range, 0.00-0.15) LogMAR which was significantly better than the mean BSCVA of 0.38 (range, 0.2-0.6) LogMAR (P = 0.007). The mean root mean square (RMS) of third-order coma and trefoil significantly decreased after MSD contact lens fitting (P = 0.012 and P = 0.015, respectively); however, changes in the fourth-order spherical aberration were not statistically significant (P = 0.336). Conclusion: Mini-scleral contact lenses may be helpful in the management of visually unsatisfied patients after corneal inlay. PMID:27621780

  3. A non-surgical approach to the management of exposure keratitis due to facial palsy by using mini-scleral lenses

    PubMed Central

    Zaki, Victor

    2017-01-01

    Abstract Rationale: This is a retrospective study aimed to determine the efficacy of mini-scleral contact lens in protecting the cornea and improving vision in cases of facial palsy. Patient concerns: Patients with facial palsy get exposure keratitis because the cornea is dry. They feel pain, discomfort and excessive watering. If left untreated, it leads to permanent damage to the cornea and loss of good functional vision. Mini-scleral lens keep the cornea covered by saline solution all wearing hours. Diagnoses: Three patients (4 eyes) with acoustic neuroma, two unilateral and one bilateral, who underwent acoustic neuroma surgeries resulting in facial palsy, are presented. The gold implant and lateral tarsorrhaphy were not enough for corneal protection. Two patients (patients 1 and 2) suffered continuous pain and watering. They had to apply thick lubricant, Lacri-Lube ointment (Allergan, Inc., Dublin, Ireland), several times daily to the affected eye for 15 years. The vision of these patients in the affected eyes were counting fingers (CF) at one foot. Patient 3 with bilateral facial palsy had exposure keratitis in both eyes resulting in constant watering, pain and blurred vision. Interventions: The 4 eyes were fitted with mini-scleral lenses. The lenses were 15.8 mm rigid gas permeable filled with preservative free saline solution that continuously covers the cornea all wearing hours. Outcomes: In patients 1 and 2 with unilateral facial palsy, vision improved through the mini-scleral lenses to 20/30 and all their symptoms disappeared. The keratitis in case 3 with bilateral facial palsy disappeared within one week of mini-scleral lens use. Follow up for 2 years showed that these patients maintained good vision with no side effects. Lessons: Mini-scleral lenses protected the cornea, gave comfort and improved the vision and the quality of life of these three patients with facial palsy and should be considered for all patients with facial palsy. PMID:28178141

  4. Cosmetic Preservatives as Therapeutic Corneal and Scleral Tissue Cross-Linking Agents

    PubMed Central

    Babar, Natasha; Kim, MiJung; Cao, Kerry; Shimizu, Yukari; Kim, Su-Young; Takaoka, Anna; Trokel, Stephen L.; Paik, David C.

    2015-01-01

    Purpose. Previously, aliphatic β-nitroalcohols (BNAs) have been studied as a means to chemically induce tissue cross-linking (TXL) of cornea and sclera. There are a number of related and possibly more potent agents, known as formaldehyde releasers (FARs), that are in commercial use as preservatives in cosmetics and other personal care products. The present study was undertaken in order to screen such compounds for potential clinical utility as therapeutic TXL agents. Methods. A chemical registry of 62 FARs was created from a literature review and included characteristics relevant to TXL such as molecular weight, carcinogenicity/mutagenicity, toxicity, hydrophobicity, and commercial availability. From this registry, five compounds [diazolidinyl urea (DAU), imidazolidinyl urea (IMU), sodium hydroxymethylglycinate (SMG), DMDM hydantoin (DMDM), 5-Ethyl-3,7-dioxa-1-azabicyclo [3.3.0] octane (OCT)] were selected for efficacy screening using two independent systems, an ex vivo rabbit corneal cross-linking simulation setup and incubation of cut scleral tissue pieces. Treatments were conducted at pH 7.4 or 8.5 for 30 minutes. Efficacy was evaluated using thermal denaturation temperature (Tm), and cell toxicity was studied using the trypan blue exclusion method. Results. Cross-linking effects in the five selected FARs were pH and concentration dependent. Overall, the Tm shifts were in agreement with both cornea and sclera. By comparison with BNAs previously reported upon, the FARs identified in this study were significantly more potent but with similar or better cytotoxicity. Conclusions. The FARs, a class of compounds well known to the cosmetic industry, may have utility as therapeutic TXL agents. The compounds studied thus far show promise and will be further tested. PMID:25634979

  5. Risk Factors for Scleral Buckle Removal: A Matched, Case-Control Study

    PubMed Central

    Covert, Douglas J.; Wirostko, William J.; Han, Dennis P.; Lindgren, Kevin E.; Hammersley, Jill A.; Connor, Thomas B.; Kim, Judy E.

    2008-01-01

    Purpose To identify preoperative, perioperative, and postoperative risk factors for scleral buckle (SB) removal. Methods A retrospective, consecutive, matched, case-control study. Cases included all patients undergoing SB removal between 1988 and 2007 at a single academic center. Case patients were matched against 4 randomly selected control patients who underwent SB implantation during the same year as the case patients. Odds ratios (ORs) were calculated for each factor investigated. Results Forty cases of SB removal and 148 matched control cases were identified. Three cases of SB removal were omitted from analysis because of incomplete records. Factors associated with SB removal for any reason, according to univariate analysis, included concurrent globe-penetrating injury at the time of SB placement (OR, 24; 95% confidence interval [CI], 2.9–200), concurrent pars plana vitrectomy (PPV) (OR, 17.3; CI, 4.9–61), diabetes mellitus (DM) (OR, 7.3; CI, 1.8–30), prior long-term topical ocular therapy (OR, 4.3; CI, 1.7–11), and subsequent ocular procedures (OR, 3.4; CI, 1.5–7.5). Factors independently associated with SB removal according to multivariate analysis included concurrent globe-penetrating injury (OR, 27.3; CI, 1.7–426), concurrent PPV (OR, 11.3; CI, 2.9–45), DM (OR, 8.9; CI, 1.3–58), and subsequent ocular procedures (OR, 3.9; CI, 1.4–11). Factors that did not alter SB removal risk included patient age; sex; and type, size, or location of buckling elements used. Conclusions Awareness of these risk factors may be valuable for the surgical planning of retinal detachment repair in patients at higher risk for subsequent SB removal and for risk stratification subsequent to SB implantation. PMID:19277232

  6. Anatomical and functional outcomes of scleral buckling versus primary vitrectomy in pseudophakic retinal detachment

    PubMed Central

    Cankurtaran, Veysel; Citirik, Mehmet; Simsek, Mert; Tekin, Kemal; Teke, Mehmet Yasin

    2017-01-01

    Retinal detachment is the separation of the sensory retina from the retinal pigment epithelium by subretinal fluid. There are several types of retinal re-attachment surgery, including scleral buckling (SB), pneumatic retinopexy, and vitrectomy (with or without SB). The objective of this study was to compare anatomical and visual outcomes between patients with pseudophakic rhegmatogenous retinal detachment (RRD) who underwent pars plana vitrectomy (PPV) with silicone oil (SO) or perfluoropropane (C3F8) gas tamponade and pseudophakic RRD patients who underwent SB surgery. We evaluated retrospectively 101 pseudophakic RRD patients from a single center. The patients were classified into three groups according to the surgical procedure performed: PPV + Silicone - patients who underwent PPV with SO tamponade; PPV + Gas - patients who underwent PPV with perfluoropropane gas tamponade; and SB group - patients who underwent SB surgery. The groups were compared with regard to primary and final anatomical and visual outcomes. The number of patients in PPV + Silicone, PPV + Gas, and SB group was 39 (38.6%), 32 (31.7%), and 30 (29.7%), respectively. The mean follow-up period in PPV + Silicone, PPV + Gas, and SB group was 33.95 ± 23.58, 32.62 ± 10.95, and 33.76 ± 16.62 months, respectively. No significant difference was observed between the groups neither with regard to primary and final anatomical and visual success rates nor in relation to the recurrence rate of retinal detachment. According to our anatomical and visual outcome results, either of the three methods (i.e. PPV + Silicone, PPV + Gas, or SB) can be used in the treatment of pseudophakic retinal detachment. PMID:28135566

  7. Incidence and risk factors for cystoid macular edema following scleral buckling.

    PubMed

    Lai, T-T; Huang, J-S; Yeh, P-T

    2016-12-09

    PurposeTo investigate the incidence of cystoid macular edema (CME) after scleral buckling (SB) and verify the possible risk factors of CME.MethodsA retrospective, non-comparative, interventional case series study was conducted. Clinical charts of 130 consecutive patients who were underwent successful SB for primary retinal detachment (RD) from 2009 to 2013 were reviewed. Optical coherence tomography (OCT) was applied to detect CME. Data pertaining to patient demographics, pre- and postoperative visual acuity, surgical procedures, and postoperative OCT findings were recorded. Factors associated with CME were also analyzed.ResultsThe incidence of CME was 9/130 (6.9%). Risk factors for developing CME were older age (non-CME vs CME: 44.8±14.8 vs 57.3±5.3 years, P<0.05), more extensive RD (RD extent by clock hours; non-CME vs CME: 4.61±1.57 vs 5.78±1.39, P<0.05), macular detachment (non-CME vs CME: 51.2 vs 88.9%, P<0.05), and external drainage (non-CME vs CME: 38.8% vs 77.8%, P<0.05). There was no significant difference between patient with and without CME regarding the use of gas tamponade and the lens status. In patients with more extensive RD (macular detachment plus RD of more than 3 clock hours before surgery), 8 of 68 patients had CME after SB and only older age and external drainage factors were associated with CME.ConclusionsThe risk factors associated with CME after SB were older age, more extended RD, macular detachment, and external drainage. External drainage should be used with caution in older patients with more extensive RD.Eye advance online publication, 9 December 2016; doi:10.1038/eye.2016.264.

  8. Anatomical and functional outcomes of scleral buckling versus primary vitrectomy in pseudophakic retinal detachment.

    PubMed

    Cankurtaran, Veysel; Citirik, Mehmet; Simsek, Mert; Tekin, Kemal; Teke, Mehmet Yasin

    2017-02-21

    Retinal detachment is the separation of the sensory retina from the retinal pigment epithelium by subretinal fluid. There are several types of retinal re-attachment surgery, including scleral buckling (SB), pneumatic retinopexy, and vitrectomy (with or without SB). The objective of this study was to compare anatomical and visual outcomes between patients with pseudophakic rhegmatogenous retinal detachment (RRD) who underwent pars plana vitrectomy (PPV) with silicone oil (SO) or perfluoropropane (C3F8) gas tamponade and pseudophakic RRD patients who underwent SB surgery. We evaluated retrospectively 101 pseudophakic RRD patients from a single center. The patients were classified into three groups according to the surgical procedure performed: PPV + Silicone - patients who underwent PPV with SO tamponade; PPV + Gas - patients who underwent PPV with perfluoropropane gas tamponade; and SB group - patients who underwent SB surgery. The groups were compared with regard to primary and final anatomical and visual outcomes. The number of patients in PPV + Silicone, PPV + Gas, and SB group was 39 (38.6%), 32 (31.7%), and 30 (29.7%), respectively. The mean follow-up period in PPV + Silicone, PPV + Gas, and SB group was 33.95 ± 23.58, 32.62 ± 10.95, and 33.76 ± 16.62 months, respectively. No significant difference was observed between the groups neither with regard to primary and final anatomical and visual success rates nor in relation to the recurrence rate of retinal detachment. According to our anatomical and visual outcome results, either of the three methods (i.e., PPV + Silicone, PPV + Gas, or SB) can be used in the treatment of pseudophakic retinal detachment.

  9. In Vivo Detection of Laminar and Peripapillary Scleral Hypercompliance in Early Monkey Experimental Glaucoma

    PubMed Central

    Ivers, Kevin M.; Yang, Hongli; Gardiner, Stuart K.; Qin, Lirong; Reyes, Luke; Fortune, Brad; Burgoyne, Claude F.

    2016-01-01

    Purpose To compare optical coherence tomography (OCT) detected, optic nerve head (ONH) compliance within control and experimental glaucoma (EG) eyes of 15 monkeys at EG onset. Methods Intraocular pressure (IOP) was chronically elevated in one eye of each animal using a laser. Experimental glaucoma onset was identified using confocal scanning laser tomography (CSLT). Optical coherence tomography ONH imaging (40 radial B-scans) was performed at 10 mm Hg before and after laser. At EG onset, OCT scans were obtained at IOP 10 and 30 mm Hg. Optical coherence tomography landmarks within the IOP 10/30 images were delineated to quantify IOP 10/30 differences (compliance) for anterior lamina cribrosa surface depth (ALCSD) relative to Bruch's membrane opening (BMO) (ALCSD-BMO), ALCSD relative to peripheral BM (ALCSD-BM), and BMO depth relative to peripheral BM (BMOD-BM). A linear mixed effects model assessed for acute IOP elevation effects, control versus EG eye effects, and their interaction Results Effects of IOP elevation were greater in EG versus control eyes for ALCSD-BMO (−46 ± 45 vs. −8 ± 13 μm, P = 0.0042) and ALCSD-BM (−92 ± 64 vs. −42 ± 22 μm, P = 0.0075). Experimental glaucoma eye-specific ALCSD-BMO and ALCSD-BM compliance exceeded the range of control eye compliance in 9 and 8 of the 15 EG eyes, respectively. Post-laser peak IOP (R2 = 0.798, P < 0.0001) and post-laser mean IOP (R2 = 0.634, P < 0.0004) most strongly correlated to EG versus control eye differences in ALCSD-BMO compliance. Conclusions Laminar (ALCSD-BMO) and peripapillary scleral (ALCSD-BM) hypercompliance are present in most monkey eyes at the onset of EG. PMID:27409498

  10. Comparison of scleral buckling using wide-angle viewing systems and indirect ophthalmoscope for rhegmatogenous retinal detachment

    PubMed Central

    Li, Xiu-Juan; Yang, Xiao-Peng; Lyu, Xiao-Bei

    2016-01-01

    AIM To compare the effects of scleral buckling using wide-angle viewing systems (WAVS) with that using indirect ophthalmoscope for the treatment of rhegmatogenous retinal detachment. METHODS The study was a retrospective analyses of the medical records of 94 eyes (94 patients) with rhegmatogenous retinal detachment. Among them, 47 eyes underwent scleral buckling using WAVS with endoilluminator (Group W), and 47 eyes underwent scleral buckling using indirect ophthalmoscope (Group I). Surgical durations, primary success rate, best-corrected visual acuities (BCVA), delayed subretinal fluid absorptions and surgical complications were compared between the two groups. RESULTS At baseline, there were no statistical differences between the two groups in patient's age (P=0.997), gender (P=0.853), symptom duration (P=0.216), BCVA (P=0.389), refractive error (P=0.167), intraocular pressure (P=0.595), the number of retinal breaks (P=0.832), the extent of retinal detachment (P=0.246), subretinal demarcation line (P=0.801), and macular detachment (P=0.811). The follow-up period was 12mo. The surgical durations in Group W (with or without encircling buckling) were significant shorter than those in Group I (P<0.001 respectively). The primary success rate was 94.27% in Group W, which was similar to that in Group I (92.38%, P = 0.931). The BCVA in Group W was better than that in Group I (P<0.001) at 1-month follow-up visit. However, there were no significant differences between the two groups at 3-month (P=0.221), 6-month (P=0.674), and 12-month (P=0.363) follow-up visits respectively. Delayed subretinal fluid absorptions were more common in Group I than in Group W at 1-month (P=0.045) follow-up visit, but there were no significant differences between the two groups at 3-month (P=0.111), 6-month (P=1.000) and 12-month follow-up visits respectively. CONCLUSION Scleral buckling using WAVS can be an alternative choose for rhegmatogenous retinal detachment. PMID:27672597

  11. Corneo-scleral rim cultures: donor contamination a case of fungal endophthalmitis transmitted by K-Sol stored cornea.

    PubMed

    Fong, L P; Gladstone, D; Casey, T A

    1988-01-01

    This retrospective study of 549 corneo-scleral rim cultures shows that gentamicin, used in MK and K-Sol medium storage at 4 degrees C, has decreased donor contamination from 43% in whole-globe storage to 13%, but failed to eliminate coagulase negative staphylococci (37%), streptococci (28%) and fungi (28%). Donor-to-host transmitted staphylococcal and streptococcal endophthalmitis have been reported previously. We present the first documented case of donor-to-recipient transmitted fungal endophthalmitis following corneal transplantation using corneas stored in MK or K-Sol solution at 4 degrees C; Candida albicans was isolated. Recommendations are made to assess critically the true incidence of donor fungal contamination and the necessity of adding anti-mycotic agents to preservation medium for 4 degrees C storage. In the absence of ideal antimicrobial cover for corneal preservation solutions, stringent prophylactic measures to reduce contamination and continued monitoring of corneo-scleral rim cultures are warranted, if the poor visual consequences of donor-to-host transmitted endophthalmitis are to be avoided.

  12. Rethinking "posterior" tongue-tie.

    PubMed

    Douglas, Pamela Sylvia

    2013-12-01

    Currently, many clinicians who help with breastfeeding problems are diagnosing "posterior" tongue-tie in infants and performing or referring for frenotomy. In this "Speaking Out" article, I argue that the diagnosis of "posterior" tongue-tie has successfully raised awareness of the importance of impaired tongue function in breastfeeding difficulty. However, the diagnosis of "posterior" tongue-tie also applies a reductionist, medicalized theoretical frame to the complex problem of impaired tongue function, risking unintended outcomes. Impaired tongue function arises out of multiple interacting and co-evolving factors, including the interplay between social behaviors concerning breastfeeding and mother-infant biology. Consideration of theoretical frames is vital if we are to build an evidence base through efficient use of the scarce resources available for clinical breastfeeding research and minimize unintended outcomes.

  13. Children's Understanding of Posterior Probability

    ERIC Educational Resources Information Center

    Girotto, Vittorio; Gonzalez, Michael

    2008-01-01

    Do young children have a basic intuition of posterior probability? Do they update their decisions and judgments in the light of new evidence? We hypothesized that they can do so extensionally, by considering and counting the various ways in which an event may or may not occur. The results reported in this paper showed that from the age of five,…

  14. Stereolithography for Posterior Fossa Cranioplasty

    PubMed Central

    Agner, Celso; Dujovny, Manuel; Evenhouse, Raymond; Charbel, Fady T.; Sadler, Lewis

    1998-01-01

    Posterior fossa cranioplasty has been suggested for improvement of neurological symptoms following craniectomy. However, there is no particular recommendation in the literature about techniques for prosthesis manufacture and implantation. We report our experience using rapid prototyping technology and stereolithography for pre-surgical implant design and production of cranioplasties. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:17171056

  15. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy.

    PubMed

    Shakespeare, Timothy J; Kaski, Diego; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Ryan, Natalie S; Schott, Jonathan M; Crutch, Sebastian J

    2015-07-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal 'visual dementia' and most common atypical Alzheimer's disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients' (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer's disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer's disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer's disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with 'sticky fixation'. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer's disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large saccadic intrusions

  16. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy

    PubMed Central

    Kaski, Diego; Yong, Keir X. X.; Paterson, Ross W.; Slattery, Catherine F.; Ryan, Natalie S.; Schott, Jonathan M.; Crutch, Sebastian J.

    2015-01-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal ‘visual dementia’ and most common atypical Alzheimer’s disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients’ (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer’s disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer’s disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer’s disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with ‘sticky fixation’. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer’s disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large

  17. Costello syndrome: Analysis of the posterior cranial fossa in children with posterior fossa crowding.

    PubMed

    Calandrelli, Rosalinda; D'Apolito, Gabriella; Marco, Panfili; Zampino, Giuseppe; Tartaglione, Tommaso; Colosimo, Cesare

    2015-06-01

    This study aimed to assess changes in the posterior cranial fossa (PCF) to shed light on the mechanism of cerebellar herniation in children with Costello syndrome (CS) and posterior fossa crowding. We performed a morphovolumetric PCF analysis on brain magnetic resonance imaging (MRI) in seven children with CS (mean age 31 ± 16 months) comparing the MRI scans with those of seven age-matched healthy subjects.PCF volume (PCFV), PCF brain volume (PCFBV) and cerebellar volume (CeV) were assessed on axial T2-weighted MRI. Morphometric parameters (diameters of the foramen magnum, tentorial angle, basiocciput, supraocciput, basisphenoid and exocciput lengths) were measured on sagittal T1-weighted MRI. The volume of the cerebrospinal fluid (CSF) spaces was calculated as PCFV minus PCFBV.Five out of seven CS children showed tonsillar herniation in the upper cervical canal; no child had hydrocephalus but three out of seven children showed ventriculomegaly. In addition, the PCFV/PCFBV ratio, PCFV, CSF spaces volume, basiocciput, basisphenoid and exocciput lengths and latero-lateral and antero-posterior diameters of the foramen magnum were significantly reduced, whereas no significant changes were found in supraocciput length, PCFBV, CeV or hindbrain volume. The volumetric reduction of the PCF due to bony posterior fossa hypoplasia is a predisposing factor for developing cerebellar tonsillar herniation through the foramen magnum in children with CS. The altered anatomy of the foramen magnum and upward expansion of the PCF secondary to an increased tentorial slope serves to explain the possible mechanism of cerebellar herniation in patients with CS.

  18. Costello syndrome: Analysis of the posterior cranial fossa in children with posterior fossa crowding

    PubMed Central

    D’Apolito, Gabriella; Panfili, Marco; Zampino, Giuseppe; Tartaglione, Tommaso; Colosimo, Cesare

    2015-01-01

    This study aimed to assess changes in the posterior cranial fossa (PCF) to shed light on the mechanism of cerebellar herniation in children with Costello syndrome (CS) and posterior fossa crowding. We performed a morphovolumetric PCF analysis on brain magnetic resonance imaging (MRI) in seven children with CS (mean age 31 ± 16 months) comparing the MRI scans with those of seven age-matched healthy subjects. PCF volume (PCFV), PCF brain volume (PCFBV) and cerebellar volume (CeV) were assessed on axial T2-weighted MRI. Morphometric parameters (diameters of the foramen magnum, tentorial angle, basiocciput, supraocciput, basisphenoid and exocciput lengths) were measured on sagittal T1-weighted MRI. The volume of the cerebrospinal fluid (CSF) spaces was calculated as PCFV minus PCFBV. Five out of seven CS children showed tonsillar herniation in the upper cervical canal; no child had hydrocephalus but three out of seven children showed ventriculomegaly. In addition, the PCFV/PCFBV ratio, PCFV, CSF spaces volume, basiocciput, basisphenoid and exocciput lengths and latero-lateral and antero-posterior diameters of the foramen magnum were significantly reduced, whereas no significant changes were found in supraocciput length, PCFBV, CeV or hindbrain volume The volumetric reduction of the PCF due to bony posterior fossa hypoplasia is a predisposing factor for developing cerebellar tonsillar herniation through the foramen magnum in children with CS. The altered anatomy of the foramen magnum and upward expansion of the PCF secondary to an increased tentorial slope serves to explain the possible mechanism of cerebellar herniation in patients with CS. PMID:26246091

  19. Distortions of posterior visual space.

    PubMed

    Phillips, Flip; Voshell, Martin G

    2009-01-01

    The study of spatial vision is a long and well traveled road (which, of course, converges to a vanishing point at the horizon). Its various distortions have been widely investigated empirically, and most concentrate, pragmatically, on the space anterior to the observer. The visual world behind the observer has received relatively less attention and it is this perspective the current experiments address. Our results show systematic perceptual distortions in the posterior visual world when viewed statically. Under static viewing conditions, observer's perceptual representation was consistently 'spread' in a hyperbolic fashion. Directions to distant, peripheral locations were consistently overestimated by about 11 degrees from the ground truth and this variability increased as the target was moved toward the center of the observer's back. The perceptual representation of posterior visual space is, no doubt, secondary to the more immediate needs of the anterior visual world. Still, it is important in some domains including certain sports, such as rowing, and in vehicular navigation.

  20. Outcome of rhegmatogenous retinal detachment repair by scleral buckling: The experience of a tertiary referral center in Scotland

    PubMed Central

    Shankar, Vikas; Lim, Lik Thai; Ah-Kee, Elliott Yann; Hammer, Harold

    2014-01-01

    Purpose: The primary aim of this study is to report the outcome of patients with rhegmatogenous retinal detachment (RRD) who underwent scleral buckling (SB) surgery. Methods: This is a retrospective noncomparative case series study of all patients who underwent RRD repair by primary SB between March 2008 and February 2009. Patient demographics, visual outcome, complications, and failure rates were identified and recorded. Results: A total of 65 patients underwent RRD repair by SB, with a mean age of 44.44 years. Results showed that the primary outcome (primary anatomical success following index surgery) was 90.77%, while the secondary outcome (anatomical success following repeat surgery) was 98.46%. Conclusion: The study showed a high-success rate of SB in phakic eyes both in terms of postoperative best-corrected visual acuity and complication rates. We recommend the continued use of this technique in selected cases of RRD. PMID:25378877

  1. Evaluation of Ahmed glaucoma valve implantation through a needle-generated scleral tunnel in Mexican children with glaucoma

    PubMed Central

    Albis-Donado, Oscar; Gil-Carrasco, Félix; Romero-Quijada, Rafael; Thomas, Ravi

    2010-01-01

    Purpose: To evaluate the results and extrusion rates of the Ahmed glaucoma valve (AGV) implantation through a needle-generated scleral tunnel, without a tube-covering patch, in children. Materials and Methods: A retrospective review of the charts of 106 Mexican children implanted with 128 AGVs operated between 1994 and 2002, with the needle track technique, at our institution, with at least six months follow up was done. Main outcome measures were intraocular pressure (IOP) control, tube extrusions or exposure and other complications. Results: Kaplan-Meier analysis demonstrated a 96.9% survival rate at six months, 82.4% at one year, 78.7% at two years, 70% at three years and 41.6% at four years. Total success at the last follow-up (IOP between 6 and 21 mm Hg without medications) was achieved in 30 eyes (23.5%), 58 eyes (45.3%) had qualified success (only topical hypotensive drugs) and 40 eyes (31.3%) were failures. The mean pre- and post-operative IOP at the last follow up was 28.4 mmHg (SD 9.3) and 14.5 mmHg (SD 6.3), respectively. No tube extrusions or exposures were observed. Tube-related complications included five retractions, a lens touch and a transitory endothelial touch. The risk of failure increased if the eye had any complication or previous glaucoma surgeries. Conclusion: Medium-term IOP control in Mexican children with glaucoma can be achieved with AGV implantation using a needle-generated tunnel, without constructing a scleral flap or using a patch to cover the tube. There were no tube extrusions, nor any tube exposures with this technique. PMID:20689189

  2. Pre-operative variables affecting final vision outcome with a critical review of ocular trauma classification for posterior open globe (zone III) injury

    PubMed Central

    Agrawal, Rupesh; Ho, Sue Wei; Teoh, Stephen

    2013-01-01

    Purpose: To identify pre-operative variables affecting the outcome of posterior open globe (zone III) injuries. Secondary objective was to re-look at the definition or landmarks for zone III injury and its clinical significance for predicting visual prognosis following open globe injury. Materials and Methods: Retrospective review of medical records of all hospitalized patients with surgical repair of open globe injury over last 10 years at a tertiary referral eye care center in Singapore. Out of 172 eyes with open globe injury, 28 eyes (16.3%) with zone III injury was identified and reviewed further. Pre-operative visual acuity (VA) and other variables, extent of scleral wound in reference to rectus insertion, relative afferent pupillary defect (RAPD) and final vision outcome were recorded. Results: Median age was 37 years with male predilection (92.9%). Mean follow-up was 12.9 months. Pre-operative VA was no light perception (NLP) in 16 (57.1%) eyes. Final VA remained NLP in 14 eyes (50.0%). The factors contributing to poor post-operative vision based on univariate regression analysis were the presence of RAPD, poor pre-operative VA, blunt trauma, extent of trauma, associated traumatic cataract, hyphema, vitreous loss and associated vitreo-retinal trauma. Further on, zone III injuries with scleral wound limited anterior to rectus insertion (6 eyes) had better vision outcome than those with injuries extending beyond rectus insertion (22 eyes). Conclusion: Initial VA, blunt ocular trauma, visual axis involvement, loss of light perception, presence of RAPD, traumatic cataract, hyphema, vitreous loss were the important determinants for final visual outcome in patients with zone III injury. Wound extending posterior to rectus insertion has poorer outcome as those limited anterior to rectus insertion. We suggest that there may be a need to relook at zone III injuries with reference to rectus insertion for prognostic significance, and further studies are warranted. PMID

  3. Posterior shoulder dislocation while lifting weights: a missed diagnosis

    PubMed Central

    Cuffolo, Giulio; Coomber, Ross; Burtt, Simon; Gray, Jim

    2014-01-01

    Summary We present a case of a 24-year-old man who suffered acute shoulder pain and subsequent inability to move his arm while lifting weights in the bench-press position. He attended A&E where he was examined and X-rays were performed. He was diagnosed with presumed pectoralis major tendon rupture and was discharged to fracture clinic the following day with analgesia. On review in clinic he was found to have a posterior shoulder dislocation and was taken to theatre for relocation under anaesthesia. This case report examines the mechanism, investigations and management of posterior shoulder dislocation. PMID:24557475

  4. Posterior commissure of the human larynx revisited.

    PubMed

    Tucker, John A; Tucker, Sean T

    2010-05-01

    The existence of the posterior commissure (PC) of the human larynx has been disputed (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). "The term posterior commissure has no relevance to anatomical structure. The term commissure means a joining together. The bilateral vocal folds never join at their posterior ends. The posterior aspect of the glottis is a wall. The posterior lateral aspect of the posterior glottis is also the lateral wall of the posterior glottis" (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). This study is intended to clarify the development of anatomical and morphological aspects of the PC in conjunction with a clinical classification of the larynx in sagittal view. This study uses human embryo and fetal laryngeal sections from the Carnegie Collection of Human Embryos (the world standard) and whole organ laryngeal sections from the Tucker Laryngeal Fetal Collection. Correlation of histologic and gross anatomical structure is made with the Hirano et al atlas, the Vidić Photographic Atlas of the Human Body, and the O'Rahilly Embryonic Atlas. Embryologic data clearly describe and illustrate the posterior union of the cricoid cartilage with formation of the PC. The anatomical functional aspects of the posterior lateral cricoid lamina as the supporting buttress of the articulating arytenoid cartilages are illustrated.

  5. Reversible posterior leucoencephalopathy syndrome associated with bone marrow transplantation.

    PubMed

    Teive, H A; Brandi, I V; Camargo, C H; Bittencourt, M A; Bonfim, C M; Friedrich, M L; de Medeiros, C R; Werneck, L C; Pasquini, R

    2001-09-01

    Reversible posterior leucoencephalopathy syndrome (RPLS) has previously been described in patients who have renal insufficiency, eclampsia, hypertensive encephalopathy and patients receiving immunosuppressive therapy. The mechanism by which immunosuppressive agents can cause this syndrome is not clear, but it is probably related with cytotoxic effects of these agents on the vascular endothelium. We report eight patients who received cyclosporine A (CSA) after allogeneic bone marrow transplantation or as treatment for severe aplastic anemia (SSA) who developed posterior leucoencephalopathy. The most common signs and symptoms were seizures and headache. Neurological dysfunction occurred preceded by or concomitant with high blood pressure and some degree of acute renal failure in six patients. Computerized tomography studies showed low-density white matter lesions involving the posterior areas of cerebral hemispheres. Symptoms and neuroimaging abnormalities were reversible and improvement occurred in all patients when given lower doses of CSA or when the drug was withdrawn. RPLS may be considered an expression of CSA neurotoxicity.

  6. Quantification of Posterior Globe Flattening: Methodology Development and Validation

    NASA Technical Reports Server (NTRS)

    Lumpkins, Sarah B.; Garcia, Kathleen M.; Sargsyan, Ashot E.; Hamilton, Douglas R.; Berggren, Michael D.; Ebert, Douglas

    2012-01-01

    Microgravity exposure affects visual acuity in a subset of astronauts and mechanisms may include structural changes in the posterior globe and orbit. Particularly, posterior globe flattening has been implicated in the eyes of several astronauts. This phenomenon is known to affect some terrestrial patient populations and has been shown to be associated with intracranial hypertension. It is commonly assessed by magnetic resonance imaging (MRI), computed tomography (CT) or B-mode Ultrasound (US), without consistent objective criteria. NASA uses a semiquantitative scale of 0-3 as part of eye/orbit MRI and US analysis for occupational monitoring purposes. The goal of this study was ot initiate development of an objective quantification methodology to monitor small changes in posterior globe flattening.

  7. Quantification of Posterior Globe Flattening: Methodology Development and Validationc

    NASA Technical Reports Server (NTRS)

    Lumpkins, S. B.; Garcia, K. M.; Sargsyan, A. E.; Hamilton, D. R.; Berggren, M. D.; Antonsen, E.; Ebert, D.

    2011-01-01

    Microgravity exposure affects visual acuity in a subset of astronauts, and mechanisms may include structural changes in the posterior globe and orbit. Particularly, posterior globe flattening has been implicated in several astronauts. This phenomenon is known to affect some terrestrial patient populations, and has been shown to be associated with intracranial hypertension. It is commonly assessed by magnetic resonance imaging (MRI), computed tomography (CT), or B-mode ultrasound (US), without consistent objective criteria. NASA uses a semi-quantitative scale of 0-3 as part of eye/orbit MRI and US analysis for occupational monitoring purposes. The goal of this study was to initiate development of an objective quantification methodology for posterior globe flattening.

  8. Isolated posterior cruciate ligament calcification

    PubMed Central

    Koukoulias, Nikolaos E; Papastergiou, Stergios G

    2011-01-01

    The authors present a case of calcified posterior cruciate ligament (PCL). A 61-year-old female presented in our department reporting 12 months history of knee pain that was getting worse during the night. The patient was under medication for epileptic seizure, osteoporosis and hyperthyroidism. X-rays demonstrated calcification of the PCL. CT and MRI excluded any other intra-articular and extra-articular pathology. Arthroscopic debridement of the calcium deposits was performed and the symptoms resolved immediately, while the postoperative x-rays were normal. Histological examination confirmed the calcium nature of the lesion. Two years postoperatively the patient remains asymptomatic. PMID:22669889

  9. Huge interparietal posterior fontanel meningohydroencephalocele

    PubMed Central

    Dos Santos, Manuel Filipe Dias; de Santa Barbara, Rita de Cassia

    2015-01-01

    Congenital encephalocele is a neural tube defect characterized by a sac-like protrusion of the brain, meninges, and other intracranial structures through the skull, which is caused by an embryonic development abnormality. The most common location is at the occipital bone, and its incidence varies according to different world regions. We report a case of an 1-month and 7-day-old male child with a huge interparietal-posterior fontanel meningohydroencephalocele, a rare occurrence. Physical examination and volumetric computed tomography were diagnostic. The encephalocele was surgically resected. Intradural and extradural approaches were performed; the bone defect was not primarily closed. Two days after surgery, the patient developed hydrocephaly requiring ventriculoperitoneal shunting. The surgical treatment of the meningohydroencephalocele of the interparietal-posterior fontanel may be accompanied by technical challenges and followed by complications due to the presence of large blood vessels under the overlying skin. In these cases, huge sacs herniate through large bone defects including meninges, brain, and blood vessels. The latter present communication with the superior sagittal sinus and ventricular system. A favorable surgical outcome generally follows an accurate strategy taking into account individual features of the lesion. PMID:26484324

  10. Longevity of Posterior Composite Restorations

    PubMed Central

    Opdam, N.J.M.; van de Sande, F.H.; Bronkhorst, E.; Cenci, M.S.; Bottenberg, P.; Pallesen, U.; Gaengler, P.; Lindberg, A.; Huysmans, M.C.D.N.J.M.; van Dijken, J.W.

    2014-01-01

    The aim of this meta-analysis, based on individual participant data from several studies, was to investigate the influence of patient-, materials-, and tooth-related variables on the survival of posterior resin composite restorations. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a search resulting in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years’ follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database including all restorations was constructed, and a multivariate Cox regression method was used to analyze variables of interest [patient (age; gender; caries-risk status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials, and use of glass-ionomer cement as base/liner (present or absent)]. The hazard ratios with respective 95% confidence intervals were determined, and annual failure rates were calculated for subgroups. Of all restorations, 2,816 (2,585 Class II and 231 Class I) were included in the analysis, of which 569 failed during the observation period. Main reasons for failure were caries and fracture. The regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. PMID:25048250

  11. A Case of Extrusion of a Solid Silicone Tire Migrating through the Superior Rectus Muscle with Aeromonas hydrophila Infection following a Scleral Buckling Procedure

    PubMed Central

    Makino, Shinji; Sato, Yukihiro

    2012-01-01

    To our knowledge, there are no reports of Aeromonas hydrophila infection after a scleral buckling procedure. Also, migration of a silicone explant element through the rectus muscles is extremely rare. Herein, we describe a case experiencing extrusion of a solid silicone tire migrating through the superior rectus muscle with Aeromonas hydrophila infection following a scleral buckling procedure. A 42-year-old man was referred to our hospital complaining of ocular pain and purulent discharge in his left eye which has persisted for several months. He had a history of bilateral rhegmatogenous retinal detachment which had been treated with scleral buckling. The left eye showed extrusion of the solid silicone buckle which had migrated through the superior rectus muscle and an infection in the upper quadrant of the sclera. The buckle was removed, and the patient was treated with antibiotics. After the removal of the buckle, the symptoms showed rapid amelioration and there was no recurrence of retinal detachment. Aeromonas hydrophila was isolated from the discharge and the removed explant. He used well water in daily life. In this case, the Aeromonas hydrophila infection of the extruded buckle might have originated from contaminated well water. PMID:23213585

  12. Study of Posterior Reversible Encephalopathy Syndrome in Children With Acute Lymphoblastic Leukemia After Induction Chemotherapy.

    PubMed

    Tang, Ji-Hong; Tian, Jian-Mei; Sheng, Mao; Hu, Shao-Yan; Li, Yan; Zhang, Li-Ya; Gu, Qing; Wang, Qi

    2016-03-01

    Increasing occurrence of posterior reversible encephalopathy syndrome has been reported in children with acute lymphoblastic leukemia. However, the etiology of posterior reversible encephalopathy syndrome is not clear. To study the possible pathogenetic mechanisms and treatment of this complication, we reported 11 cases of pediatric acute lymphoblastic leukemia who developed posterior reversible encephalopathy syndrome after induction chemotherapy. After appropriate treatment, the clinical symptoms of posterior reversible encephalopathy syndrome in most cases disappeared even though induction chemotherapy continued. During the 1-year follow-up, no recurrence of posterior reversible encephalopathy syndrome was observed. Although the clinical and imaging features of posterior reversible encephalopathy syndrome may be diverse, posterior reversible encephalopathy syndrome should be recognized as a possible important complication of acute lymphoblastic leukemia when neurologic symptoms appear. In line with previous reports, our study also indicated that posterior reversible encephalopathy syndrome was reversible when diagnosed and treated at an early stage. Thus, the occurrence of posterior reversible encephalopathy syndrome should be considered and investigated to optimize the early induction scheme of acute lymphoblastic leukemia treatment.

  13. Imaging of the Posterior Skull Base.

    PubMed

    Job, Joici; Branstetter, Barton F

    2017-01-01

    The posterior skull base can be involved by a variety of pathologic processes. They can be broadly classified as: traumatic, neoplastic, vascular, and inflammatory. Pathology in the posterior skull base usually involves the lower cranial nerves, either as a source of pathology or a secondary source of symptoms. This review will categorize pathology arising in the posterior skull base and describe how it affects the skull base itself and surrounding structures.

  14. Posterior peritoneal recesses: assessment using CT

    SciTech Connect

    Rubenstein, W.A.; Auh, Y.H.; Zirinsky, K.; Kneeland, J.B.; Whalen, J.P.; Kazam, E.

    1985-08-01

    Intraperitoneal compartments may extend posteriorly to the level of known retroperitoneal structures at several locations within the abdomen. These locations include the posterior subhepatic or hepatorenal space, the splenorenal space, the retropancreatic recess, the paracolic gutters, and the pararectal fossae. Because of their posterior location, fluid collections within these compartments may be mistaken radiologically for retroperitoneal masses. The sectional anatomy of these spaces and particularly their appearance on computed tomographic scans, are illustrated in this paper.

  15. Posterior ankle impingement in the dancer.

    PubMed

    Moser, Brad R

    2011-01-01

    Dancers spend a lot of time in the relevé position in demi-pointe and en pointe in their training and their careers. Pain from both osseous and soft tissue causes may start to occur in the posterior aspect of their ankle. This article reviews the potential causes of posterior ankle impingement in dancers. It will discuss the clinical evaluation of a dancer and the appropriate workup and radiographic studies needed to further evaluate a dancer with suspected posterior ankle impingement.

  16. Bladder neck incompetence at posterior urethroplasty

    PubMed Central

    Koraitim, Mamdouh M.

    2015-01-01

    The finding of an incompetent bladder neck (BN) at the time of posterior urethroplasty will necessarily exacerbate the already difficult situation. In such cases the aim of the treatment is not only to restore urethral continuity by end-to-end urethral anastomosis, but also to restore the function of the BN to maintain urinary continence. Fortunately, the incidence of incompetence of the BN at posterior urethroplasty is uncommon, usually ≈4.5%. It seems that pelvic fracture-related BN injuries, in contrast to urethral injuries which result from a shearing force, are due to direct injury by the sharp edge of the fractured and displaced pubic bone. The risk of injuries to the BN is greater in children, in patients with a fracture involving both superior and inferior pubic rami on the same side, and in those managed initially by primary realignment. An incompetent BN is suspected by finding an open rectangular BN on cystography, and a fixedly open BN on suprapubic cystoscopy. An incompetent BN can be treated either subsequent to or concomitant with the urethral repair, according to whether a perineal or a perineo-abdominal urethroplasty is used, respectively. Several options have been reported to treat pelvic fracture-related BN incompetence, including reconstructing the BN, forming a new sphincter by tubularisation of a rectangular flap of the anterior bladder wall, and mechanical occlusion by an artificial sphincter or collagen injection. Reconstruction of the BN by the Young-Dees-Leadbetter∗∗ procedure probably provides the most successful results. PMID:26019982

  17. Collagen Architecture of the Posterior Pole: High-Resolution Wide Field of View Visualization and Analysis Using Polarized Light Microscopy

    PubMed Central

    Jan, Ning-Jiun; Lathrop, Kira; Sigal, Ian A.

    2017-01-01

    Purpose The purpose of this study was to leverage polarized light microscopy (PLM) to visualize the collagen fiber architecture of posterior pole and optic nerve head with micrometer-scale resolution and to identify and quantify major organizational components. Methods Eight sheep posterior poles were cryosectioned and imaged using PLM. Collagen fiber orientation was determined by using custom scripts, and the resulting orientation maps were inspected and quantified to identify major structural elements and tested for differences in mean fiber orientation and anisotropy, using linear mixed effect models. Results Images revealed an intricate organization of collagen fibers in the posterior pole. In the lamina cribrosa, interweaving fibers formed large knots and wrapped around nerve fiber pores, with beam insertions into the scleral canal wall that were either narrow and straight or wide. In the peripapillary sclera, three significantly different (P < 0.0001) components were identified: fibers oriented circumferentially proximal to the canal, radially in the innermost sclera, and unaligned with interweaving fibers. The radial fibers were between 60 and 180 μm thick, extending at least 3 mm from the canal. Conclusions PLM revealed structural aspects of the lamina cribrosa and sclera that may have important biomechanical roles but that were previously unreported or not characterized quantitatively. In the lamina cribrosa, these roles included wide and narrow beam insertions and details of collagen fibers interweaving and wrapping around the pores. In the sclera, we described regions of circumferential, radial, and unaligned “random” fibers. Although there is consensus that circumferential fibers protect neural tissues by resisting canal expansion, the role of the radial fibers remains unclear. PMID:28146238

  18. Computational Simulation of Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment: On the Effect of the Band Size on the Myopization.

    PubMed

    Lanchares, Elena; Del Buey, María A; Cristóbal, José A; Calvo, Begoña; Ascaso, Francisco J; Malvè, Mauro

    2016-01-01

    A finite element model (FE) of the eye including cornea, sclera, crystalline lens, and ciliary body was created to analyze the influence of the silicone encircling bandwidth and the tightness degree on the myopia induced by scleral buckling (SB) procedure for rhegmatogenous retinal detachment. Intraocular pressure (IOP) was applied to the reference geometry of the FE model and then SB surgery was simulated with encircling bandwidths of 1, 2, and 2.5 mm. Different levels of tightening and three values of IOP were applied. The anterior segment resulted as unaffected by the surgery. The highest value of Cauchy stress appeared in the surroundings of the implant, whereas no increment of stress was observed either in anterior segment or in the optic nerve head. The initial IOP did not appear to play any role in the induced myopia. The wider the band, the greater the induced myopia: 0.44, 0.88, and 1.07 diopters (D) for the 1, 2, and 2.5 mm bandwidth, respectively. Therefore, patients become more myopic with a wider encircling element. The proposed simulations allow determining the effect of the bandwidth or the tightness degree on the axial lengthening, thus predicting the myopic increment caused by the encircling surgery.

  19. A retrospective study comparing outcomes of primary rhegmatogenous retinal detachment repair by scleral buckling and pars plana vitrectomy in Finland

    PubMed Central

    Sahanne, Sari; Tuuminen, Raimo; Haukka, Jari; Loukovaara, Sirpa

    2017-01-01

    Background Rhegmatogenous retinal detachment (RRD) is the most common form of retinal detachment and an ophthalmic emergency. Here, we compared outcomes of primary RRD eyes operated with conventional scleral buckling (SB) with cryoretinopexy to those operated with standard pars plana vitrectomy (PPV). Methods This is an institutional, retrospective, register-based, observational, comparative study. Based on the surgical procedure, 319 eyes of 319 patients were divided into two groups: SB plus cryotherapy (n=50) and PPV (n=269). Changes in intraocular pressure (IOP) and best-corrected visual acuity (BCVA) were recorded at 30 days and reoperation rates within 180 days postoperatively. Results Eyes operated with PPV had less reoperations within the first 180 days as compared with SB eyes (P=0.001, log-rank test); however, changes in IOP were more prominent (mean ± standard deviation: +8.1±8.8 vs. +4.4±7.0 mmHg, respectively; P=0.006). Changes in BCVA did not differ between the surgical procedures. Conclusion PPV was associated with higher primary anatomic success rates and lower risk of reoperation but significant IOP elevation when compared to SB. These factors should be case-specifically considered when choosing treatment modality for primary RRD. PMID:28331284

  20. The impact of new methods of investigation and treatment on the understanding of the pathology of scleral inflammation

    PubMed Central

    Watson, P; Romano, A

    2014-01-01

    Recent advances in the understanding of the initiation and perpetuation of the immune response strongly suggest that all forms of noninfective immunologically induced scleral inflammation have a common origin. Analysis of the progress of patients with scleritis corroborates the current clinical classification that, together with studies of the immunohistology fluoresceine/ICG angiography, 3D proteoglycan, and keratan sulphate electron microscopy of scleritis, strongly suggests that from the initiation of the inflammatory process, necrotizing scleritis and diffuse and nodular scleritis not only pursue a different course but also have a different pathogenesis; nonnecrotizing scleritis being the consequence of an auto immune response, whereas necrotizing scleritis being the complication of an already present (if not always manifest), systemic immune-mediated systemic disease and its associated vasculitis. The increasing imaging capacity of anterior segment ocular coherence tomography (OCT) and en face OCT enables the changes occurring in the sclera during the course of the disease to be observed for the first time. These observations suggest that the inflammatory changes involve the potential suprachoroidal space between choroid and sclera, an observation supported by the presence of subscleral granulomas on histopathology. New imaging techniques have also been able to explain the changes seen in the cornea as a complication of scleritis. These findings have implications for investigation and the treatment of these conditions. PMID:24875228

  1. Comparing the accuracy of video-oculography and the scleral search coil system in human eye movement analysis.

    PubMed

    Imai, Takao; Sekine, Kazunori; Hattori, Kousuke; Takeda, Noriaki; Koizuka, Izumi; Nakamae, Koji; Miura, Katsuyoshi; Fujioka, Hiromu; Kubo, Takeshi

    2005-03-01

    The measurement of eye movements in three dimensions is an important tool to investigate the human vestibular and oculomotor system. The primary methods for three dimensional eye movement measurement are the scleral search coil system (SSCS) and video-oculography (VOG). In the present study, we compare the accuracy of VOG with that of SSCS using an artificial eye. We then analyzed the Y (pitch) and Z (yaw) component of human eye movements during saccades, smooth pursuit and optokinetic nystagmus, and the X (roll) component of human eye movement during the torsional vestibulo-ocular reflex induced by rotation in normal subjects, using simultaneous VOG and SSCS measures. The coefficients of the linear relationship between the angle of a simulated eyeball and the angle measured by both VOG and SSCS was almost unity with y-intercepts close to zero for torsional (X), vertical (Y) and horizontal (Z) movements, indicating that the in vitro accuracy of VOG was similar to that of SSCS. The average difference between VOG and SSCS was 0.56 degrees , 0.78 degrees and 0.18 degrees for the X, Y and Z components of human eye movements, respectively. Both the in vitro and in vivo comparisons demonstrate that VOG has accuracy comparable to SSCS, and is a reliable method for measurement of three dimensions (3D) human eye movements.

  2. Computational Simulation of Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment: On the Effect of the Band Size on the Myopization

    PubMed Central

    Lanchares, Elena; del Buey, María A.; Cristóbal, José A.; Ascaso, Francisco J.

    2016-01-01

    A finite element model (FE) of the eye including cornea, sclera, crystalline lens, and ciliary body was created to analyze the influence of the silicone encircling bandwidth and the tightness degree on the myopia induced by scleral buckling (SB) procedure for rhegmatogenous retinal detachment. Intraocular pressure (IOP) was applied to the reference geometry of the FE model and then SB surgery was simulated with encircling bandwidths of 1, 2, and 2.5 mm. Different levels of tightening and three values of IOP were applied. The anterior segment resulted as unaffected by the surgery. The highest value of Cauchy stress appeared in the surroundings of the implant, whereas no increment of stress was observed either in anterior segment or in the optic nerve head. The initial IOP did not appear to play any role in the induced myopia. The wider the band, the greater the induced myopia: 0.44, 0.88, and 1.07 diopters (D) for the 1, 2, and 2.5 mm bandwidth, respectively. Therefore, patients become more myopic with a wider encircling element. The proposed simulations allow determining the effect of the bandwidth or the tightness degree on the axial lengthening, thus predicting the myopic increment caused by the encircling surgery. PMID:27413542

  3. Anterior and posterior corneal stroma elasticity assessed using nanoindentation

    PubMed Central

    Dias, Janice; Ziebarth, Noël M.

    2013-01-01

    Corneal biomechanics is an essential parameter for developing diagnostic and treatment methods of corneal-related diseases. It is widely accepted that corneal mechanical strength stems from the stroma's collagenous composition. However, more comprehensive insight into the mechanical properties within the stroma is needed to improve current corneal diagnostic and treatment techniques. The purpose of this study was to perform elasticity characterization of anterior and posterior stromal regions of human corneas using atomic force microscopy (AFM). Nine pairs of human whole globes were placed in 20% Dextran solution, cornea side down, to restore the corneal thickness to physiological levels (400-600μm). The epithelium and Bowman's membrane were removed from all eyes. Anterior stromal AFM elasticity testing was then performed on left (OS) eyes. Additional stroma was removed from right (OD) eyes to allow posterior stromal measurements at a depth of 50% of the original thickness. All experiments were performed with corneas submerged in 15% Dextran to maintain corneal hydration. The results of the study showed that the Young's modulus of elasticity of the anterior stroma (average: 281 ± 214kPa; range: 59-764kPa) was significantly higher than that of the posterior stroma (average: 89.5 ± 46.1kPa; range: 29-179kPa) (p=0.014). In addition, a linear relationship was found between the posterior stromal elasticity and anterior stromal elasticity (p=0.0428). On average, the elasticity of the posterior stroma is 39.3% of the anterior stroma. In summary, there appears to be an elasticity gradient within the corneal stroma, which should be considered in the design and development of corneal diagnostic and treatment methods to enhance efficacy. PMID:23800511

  4. Expression of Wnt/β-Catenin Signaling Pathway and Its Regulatory Role in Type I Collagen with TGF-β1 in Scleral Fibroblasts from an Experimentally Induced Myopia Guinea Pig Model

    PubMed Central

    Li, Min; Yuan, Ying; Chen, Qingzhong; Me, Rao; Gu, Qing; Yu, Yunjie; Sheng, Minjie; Ke, Bilian

    2016-01-01

    Background. To investigate Wnt/β-catenin signaling pathway expression and its regulation of type I collagen by TGF-β1 in scleral fibroblasts from form-deprivation myopia (FDM) guinea pig model. Methods. Wnt isoforms were examined using genome microarrays. Scleral fibroblasts from FDM group and self-control (SC) group were cultured. Wnt isoforms, β-catenin, TGF-β1, and type I collagen expression levels were examined in the two groups with or without DKK-1 or TGF-β1 neutralizing antibody. Results. For genome microarrays, the expression of Wnt3 in FDM group was significantly greater as confirmed in retinal and scleral tissue. The expression of Wnt3 and β-catenin significantly increased in FDM group and decreased significantly with DKK-1. TGF-β1 expression level decreased significantly in FDM group and increased significantly with DKK-1. Along with morphological misalignment inside and outside cells, the amount of type I collagen decreased in FDM group. Furthermore, type I collagen increased and became regular in DKK-1 intervention group, whereas it decreased and rearranged more disorder in TGF-β1 neutralizing antibody intervention group. Conclusions. The activation of Wnt3/β-catenin signaling pathway was demonstrated in primary scleral fibroblasts in FDM. This pathway further reduced the expression of type I collagen by TGF-β1, which ultimately played a role in scleral remodeling during myopia development. PMID:27247798

  5. Bilateral posterior shoulder dislocation after electrical shock: A case report

    PubMed Central

    Ketenci, Ismail Emre; Duymus, Tahir Mutlu; Ulusoy, Ayhan; Yanik, Hakan Serhat; Mutlu, Serhat; Durakbasa, Mehmet Oguz

    2015-01-01

    Introduction Posterior dislocation of the shoulder is a rare and commonly missed injury. Unilateral dislocations occur mostly due to trauma. Bilateral posterior shoulder dislocations are even more rare and result mainly from epileptic seizures. Electrical injury is a rare cause of posterior shoulder dislocation. Injury mechanism in electrical injury is similar to epileptic seizures, where the shoulder is forced to internal rotation, flexion and adduction. Presentation of case This report presents a case of bilateral posterior shoulder dislocation after electrical shock. We were able to find a few individual case reports describing this condition. The case was acute and humeral head impression defects were minor. Our treatment in this case consisted of closed reduction under general anesthesia and applying of orthoses which kept the shoulders in abduction and external rotation. A rehabilitation program was begun after 3 weeks of immobilization. After 6 months of injury the patient has returned to work. 20 months postoperatively, at final follow-up, he was painless and capable of performing all of his daily activities. Discussion The amount of bilateral shoulder dislocations after electrical injury is not reported but is known to be very rare. The aim of this case presentation is to report an example for this rare entity, highlight the difficulties in diagnosis and review the treatment options. Conclusion Physical examination and radiographic evaluation are important for quick and accurate diagnosis. PMID:26904192

  6. Posterior repair and sexual function

    PubMed Central

    Komesu, Yuko M.; Rogers, Rebecca G.; Kammerer-Doak, Dorothy N.; Barber, Matthew D.; Olsen, Ambre L.

    2011-01-01

    OBJECTIVE The purpose of this study was to determine the effect of posterior repair (PR) on sexual function in patients who have undergone incontinence and/or pelvic reconstructive surgery. STUDY DESIGN A cohort study of women who underwent incontinence and/or prolapse surgery was performed. Participants completed the pelvic organ prolapse urinary incontinence sexual questionnaire (PISQ) before and after the operation. PISQ scores were compared between women who underwent PR and women who did not. RESULTS Of 73 study participants, 30 women underwent PR; 43 women did not (no PR). Although there was no difference in dyspareunia between groups pre-op, dyspareunia prevalence post-op was significantly lower in the no PR group. Preoperative PISQ scores were similar between groups. After the operation, both groups significantly improved their PISQ scores, without a difference between groups. CONCLUSION Although the incidence of dyspareunia differed between PR and no PR groups, overall improvement in sexual function was reflected in improved total PISQ scores that occurred irrespective of PR performance. PMID:17618777

  7. Posterior regeneration in Isodiametra pulchra (Acoela, Acoelomorpha)

    PubMed Central

    2013-01-01

    Introduction Regeneration is a widespread phenomenon in the animal kingdom, but the capacity to restore damaged or missing tissue varies greatly between different phyla and even within the same phylum. However, the distantly related Acoelomorpha and Platyhelminthes share a strikingly similar stem-cell system and regenerative capacity. Therefore, comparing the underlying mechanisms in these two phyla paves the way for an increased understanding of the evolution of this developmental process. To date, Isodiametra pulchra is the most promising candidate as a model for the Acoelomorpha, as it reproduces steadily under laboratory conditions and is amenable to various techniques, including the silencing of gene expression by RNAi. In order to provide an essential framework for future studies, we report the succession of regeneration events via the use of cytochemical, histological and microscopy techniques, and specify the total number of cells in adult individuals. Results Isodiametra pulchra is not capable of regenerating a new head, but completely restores all posterior structures within 10 days. Following amputation, the wound closes via the contraction of local muscle fibres and an extension of the dorsal epidermis. Subsequently, stem cells and differentiating cells invade the wound area and form a loosely delimited blastema. After two days, the posterior end is re-patterned with the male (and occasionally the female) genital primordium being apparent. Successively, these primordia differentiate into complete copulatory organs. The size of the body and also of the male and female copulatory organs, as well as the distance between the copulatory organs, progressively increase and by nine days copulation is possible. Adult individuals with an average length of 670 μm consist of approximately 8100 cells. Conclusion Isodiametra pulchra regenerates through a combination of morphallactic and epimorphic processes. Existing structures are “re-modelled” and provide a

  8. Predictive factors for postoperative visual function of primary chronic rhegmatogenous retinal detachment after scleral buckling

    PubMed Central

    Fang, Wei; Li, Jiu-Ke; Jin, Xiao-Hong; Dai, Yuan-Min; Li, Yu-Min

    2016-01-01

    AIM To evaluate predictive factors for postoperative visual function of primary chronic rhegmatgenous retinal detachment (RRD) after sclera buckling (SB). METHODS Totally 48 patients (51 eyes) with primary chronic RRD were included in this prospective interventional clinical cases study, which underwent SB alone from June 2008 to December 2014. Age, sex, symptoms duration, detached extension, retinal hole position, size, type, fovea on/off, proliferative vitreoretinopathy (PVR), posterior vitreous detachment (PVD), baseline best corrected visual acuity (BCVA), operative duration, follow up duration, final BCVA were measured. Pearson correlation analysis, Spearman correlation analysis and multivariate linear stepwise regression were used to confirm predictive factors for better final visual acuity. Student's t-test, Wilcoxon two-sample test, Chi-square test and logistic stepwise regression were used to confirm predictive factors for better vision improvement. RESULTS Baseline BCVA was 0.8313±0.6911 logMAR and final BCVA was 0.4761±0.4956 logMAR. Primary surgical success rate was 92.16% (47/51). Correlation analyses revealed shorter symptoms duration (r=0.3850, P=0.0053), less detached area (r=0.5489, P<0.0001), fovea (r=0.4605, P=0.0007), no PVR (r=0.3138, P=0.0250), better baseline BCVA (r=0.7291, P<0.0001), shorter operative duration (r=0.3233, P=0.0207) and longer follow up (r=-0.3358, P=0.0160) were related with better final BCVA, while independent predictive factors were better baseline BCVA [partial R-square (PR2)=0.5316, P<0.0001], shorter symptoms duration (PR2=0.0609, P=0.0101), longer follow up duration (PR2=0.0278, P=0.0477) and shorter operative duration (PR2=0.0338, P=0.0350). Patients with vision improvement took up 49.02% (25/51). Univariate and multivariate analyses both revealed predictive factors for better vision improvement were better baseline vision [odds ratio (OR) =50.369, P=0.0041] and longer follow up duration (OR=1.144, P=0

  9. [Giant retinal tears treated with lens sparing, bimanual 23 g vitrectomy without scleral buckle].

    PubMed

    Quezada-Ruiz, Carlos; Cano-Hidalgo, Rene Alfredo

    2014-01-01

    Antecedentes: el desgarro retiniano gigante es la rotura del espesor total de la retina neurosensorial con extensión circunferencial de 3 o más husos horarios aunado a desprendimiento de vítreo posterior, y constituye uno de los escenarios quirúrgicos más complejos para el cirujano de retina y vítreo. No existe consenso en cuanto a su manejo; sin embargo, tradicionalmente se ha empleado un abordaje que combina lensectomía, cerclaje y vitrectomía. Objetivo: reportar la evolución a dos años de 5 pacientes con desgarro gigante tratados con vitrectomía 23 g, abordaje bimanual, sin lensectomía y sin cerclaje escleral. Material y métodos: estudio descriptivo, retrospectivo de pacientes con desgarro retiniano gigante, tratados con vitrectomía 23 g, abordaje bimanual, sin lensectomía ni cerclaje escleral. Se estudiaron la edad, estado del cristalino, etiología y extensión del desgarro, agudeza visual, resultado anatómico, taponamiento usado, criopexia o láser. Resultados: se incluyeron 3 pacientes con miopía alta, 1 con traumatismo contuso y 1 con síndrome de Wagner-Stickler. La extensión del desgarro fue de 120 a 280°. Todos con éxito anatómico y mejoría de la agudeza visual. Un paciente con vitreorretinopatía proliferativa se reintervino y la retina permaneció aplicada hasta el final del periodo analizado. Conclusiones: en este selecto grupo de pacientes la vitrectomía calibre 23 con abordaje bimanual, sin cerclaje escleral y sin tocar el cristalino, dio buenos resultados anatómicos y visuales en un seguimiento a dos años. Para establecer el papel que corresponde a esta técnica en el tratamiento de esta compleja patología se requieren estudios prospectivos y comparativos.

  10. Treatment implications of posterior fossa ependymoma subgroups.

    PubMed

    Ramaswamy, Vijay; Taylor, Michael D

    2016-11-15

    Posterior fossa ependymoma comprises two distinct molecular entities, ependymoma_posterior fossa A (EPN_PFA) and ependymoma_posterior fossa B (EPN_PFB), with differentiable gene expression profiles. As yet, the response of the two entities to treatment is unclear. To determine the relationship between the two molecular subgroups of posterior fossa ependymoma and treatment, we studied a cohort of 820 patients with molecularly profiled, clinically annotated posterior fossa ependymomas. We found that the strongest predictor of poor outcome in patients with posterior fossa ependymoma across the entire age spectrum was molecular subgroup EPN_PFA, which was recently reported in the paper entitled "Therapeutic impact of cytoreductive surgery and irradiation of posterior fossa ependymoma in the molecular era: a retrospective multicohort analysis" in the Journal of Clinical Oncology. Patients with incompletely resected EPN_PFA tumors had a very poor outcome despite receiving adjuvant radiation therapy, whereas a substantial proportion of patients with EPN_PFB tumors can be cured with surgery alone.

  11. Congenital basis of posterior fossa anomalies

    PubMed Central

    Cotes, Claudia; Bonfante, Eliana; Lazor, Jillian; Jadhav, Siddharth; Caldas, Maria; Swischuk, Leonard

    2015-01-01

    The classification of posterior fossa congenital anomalies has been a controversial topic. Advances in genetics and imaging have allowed a better understanding of the embryologic development of these abnormalities. A new classification schema correlates the embryologic, morphologic, and genetic bases of these anomalies in order to better distinguish and describe them. Although they provide a better understanding of the clinical aspects and genetics of these disorders, it is crucial for the radiologist to be able to diagnose the congenital posterior fossa anomalies based on their morphology, since neuroimaging is usually the initial step when these disorders are suspected. We divide the most common posterior fossa congenital anomalies into two groups: 1) hindbrain malformations, including diseases with cerebellar or vermian agenesis, aplasia or hypoplasia and cystic posterior fossa anomalies; and 2) cranial vault malformations. In addition, we will review the embryologic development of the posterior fossa and, from the perspective of embryonic development, will describe the imaging appearance of congenital posterior fossa anomalies. Knowledge of the developmental bases of these malformations facilitates detection of the morphological changes identified on imaging, allowing accurate differentiation and diagnosis of congenital posterior fossa anomalies. PMID:26246090

  12. Recurrent posterior shoulder instability. Diagnosis and treatment.

    PubMed

    Pollock, R G; Bigliani, L U

    1993-06-01

    Recurrent posterior glenohumeral instability is regarded as a difficult problem to diagnose and treat. A careful history and physical examination are the most helpful tools in making this diagnosis. A positive posterior stress test, demonstrable posterior subluxation, and a sulcus sign are frequently present on examination. Special roentgenographic studies, such as the computerized arthrotomography (arthro-CT) scan, may be used in cases in which plain roentgenographs suggest bony glenoid abnormalities. When conservative therapy fails, there is no consensus on the operative treatment. Procedures that address the soft tissues, such as capsulorrhaphy and posterior labral repair, as well as those that alter the bony geometry of the joint, such as posterior bone blocks and glenoid or humeral osteotomies, have been described. Capsular laxity is the most common pathologic finding in the authors' experience, and they favor the use of a posterior-inferior capsular shift procedure to correct this problem. Augmentation of the repair with a posterior bone block is reserved for unusual cases, such as when glenoid hypoplasia is present or in certain revision situations.

  13. Posterior labral injury in contact athletes.

    PubMed

    Mair, S D; Zarzour, R H; Speer, K P

    1998-01-01

    Nine athletes (seven football offensive linemen, one defensive lineman, and one lacrosse player) were found at arthroscopy to have posterior labral detachment from the glenoid. In our series, this lesion is specific to contact athletes who engage their opponents with arms in front of the body. All patients had pain with bench pressing and while participating in their sport, diminishing their ability to play effectively. Conservative measures were ineffective in relieving their symptoms. Examination under anesthesia revealed symmetric glenohumeral translation bilaterally, without evidence of posterior instability. Treatment consisted of glenoid rim abradement and posterior labral repair with a bioabsorbable tack. All patients returned to complete at least one full season of contact sports and weightlifting without pain (minimum follow-up, > or = 2 years). Although many injuries leading to subluxation of the glenohumeral joint occur when an unanticipated force is applied, contact athletes ready their shoulder muscles in anticipation of impact with opponents. This leads to a compressive force at the glenohumeral joint. We hypothesize that, in combination with a posteriorly directed force at impact, the resultant vector is a shearing force to the posterior labrum and articular surface. Repeated exposure leads to posterior labral detachment without capsular injury. Posterior labral reattachment provides consistently good results, allowing the athlete to return to competition.

  14. Argus II retinal prosthesis implantation with scleral flap and autogenous temporalis fascia as alternative patch graft material: a 4-year follow-up

    PubMed Central

    Matet, Alexandre; Amar, Nawel; Mohand-Said, Saddek; Sahel, José-Alain; Barale, Pierre-Olivier

    2016-01-01

    Introduction The Argus II retinal prosthesis is composed of an epiretinal electrode array positioned over the macula and connected to an extrascleral electronics case via a silicone cable, running through a sclerotomy. During implantation, the manufacturer recommends to cover the sclerotomy site with a patch of processed human pericardium to prevent postoperative hypotony and conjunctival erosion by the underlying electronics case. Due to biomedical regulations prohibiting the use of this material in France, we developed an alternative technique combining a scleral flap protecting the sclerotomy and an autogenous graft of superior temporalis fascia overlying the electronics case. Methods The purpose of this study is to describe the 4-year outcomes of this modified procedure in three subjects who underwent Argus II Retinal Prosthesis System implantation. Clinical data consisting of intraocular pressure measurements and tolerance in terms of conjunctival erosion or inflammation were retrospectively assessed over a 4-year postoperative follow-up. Results None of the three patients implanted with the modified technique developed ocular hypotony over 4 years. A normal, transient conjunctival inflammation occurred during the first postoperative month but conjunctival erosion was not observed in any of the three patients over 4 years. Four years after implantation, the autogenous temporalis fascia graft remained well tolerated and the retinal prosthesis was functional in all three patients. Conclusion The combination of an autograft of superficial temporalis fascia and a scleral flap efficiently prevented leakage through the sclerotomy site, ocular hypotony, and conjunctival erosion by the extrascleral electronics case. This modified technique is suitable for the implantation of existing and forthcoming retinal prostheses. Superficial temporalis fascia may also be used as alternative to commercial tectonic tissues for scleral wound repair in clinical settings where they

  15. Comparison of outcomes: scleral buckling and pars plana vitrectomy versus vitrectomy alone for primary repair of rhegmatogenous retinal detachment

    PubMed Central

    Lindsell, Luke B; Sisk, Robert A; Miller, Daniel M; Foster, Robert E; Petersen, Michael R; Riemann, Christopher D; Hutchins, Robert K

    2017-01-01

    Objective To assess the combination of scleral buckling (SB) and pars plana vitrectomy (PPV) versus PPV alone in the primary repair of rhegmatogenous retinal detachments (RRDs). Methods The current study was a retrospective, comparative, interventional, consecutive case series of 179 eyes of 174 patients who underwent primary RRD repair by five surgeons between January 1, 2008 and December 31, 2010, utilizing SB with PPV or PPV. Univariate and multivariate analyses were used to compare the efficacy of the two surgical strategies and assess for risk factors of proliferative vitreoretinopathy (PVR). Results Single surgery anatomic success (SSAS) was similar (P=0.76) between the PPV group (112 of 132 eyes, 85%) and SB with PPV group (39 of 47 eyes, 83%). Final anatomic success was 100% in each group. There was no difference in rates of PVR formation (PPV 16% vs SB with PPV 19%, P=0.70). Final logarithm of the minimum angle of resolution acuity was 0.33 (20/43) in the PPV group and 0.37 (20/47) in the SB with PPV group (P=0.62). Postoperative anterior chamber fibrin was highly correlated with PVR formation (PVR 13% vs no PVR 0.7%, P=0.003; odds ratio =68.37, P=0.007). Separate analysis of medium- to high-complexity cases showed similar SSAS (PPV 86% vs SB with PPV 83%, P=0.45). Conclusion SB with PPV versus PPV alone were similarly efficacious for repair of primary RRDs of varying complexity. SSAS rates, PVR incidence, and final visual acuities were not significantly different. PMID:28053500

  16. Topical, Aqueous, Clear Cyclosporine Formulation Design for Anterior and Posterior Ocular Delivery

    PubMed Central

    Cholkar, Kishore; Gilger, Brian C.; Mitra, Ashim K.

    2015-01-01

    Purpose: The main objective of this study was to optimize cyclosporine (CsA) nanomicellar solution and study in vivo ocular CsA tissue distribution with a topical drop. Methods: An optimized blend of hydrogenated castor oil-40 and octoxynol-40 was prepared to entrap CsA within nanomicelles. In vivo studies were conducted in New Zealand White albino rabbits with topical drop instillation. Results: Average size of CsA-loaded nanomicelles was approximately 22.4 nm. Ocular tissue CsA quantification with single and multiple dosing revealed that CsA levels followed as cornea → iris-ciliary body → aqueous humor → lens. Cyclosporine levels were also found to be in the following order: conjunctiva → sclera → retina/choroid → vitreous humor. High CsA level was detected in retina/choroid (53.7 ng/g tissue). Conclusions: Ocular tissue CsA distribution studies revealed high CsA concentrations in anterior ocular tissues. Moreover, it appears that nanomicelles are transported through a conjunctival–scleral pathway and deliver CsA to the retina/choroid. Results suggest polymeric blend to be a safe carrier for anterior and posterior ocular tissues. Translational Relevance: This study has significant translational relevance, disclosing results that suggest that aqueous nanomicellar approach can provide high corneal and conjunctival CsA concentrations. Aqueous nanomicelles can deliver high drug concentrations not only to anterior but also to back of the eye tissues, including retina. This article provides a platform for noninvasive back of the eye drug delivery with topical eye drops. Aqueous CsA nanomicelles have no perceptible toxicity such as cell membrane damage or cytotoxicity to corneal and retinal pigment epithelial cells. Clear aqueous nanomicellar solution can be translated to human conditions for keratoconjunctivitis sicca and other anti-inflammatory conditions. PMID:25964868

  17. Scleral buckling versus vitrectomy for macula-off rhegmatogenous retinal detachment as accessed with spectral-domain optical coherence tomography: a retrospective observational case series

    PubMed Central

    2013-01-01

    Background Scleral buckling surgery and pars plana vitrectomy are competing methods in the treatment of retinal detachment. The recent development of spectral-domain optical coherence tomography (SD-OCT) has dramatically improved the visualization of the photoreceptor layer relative to conventional OCT, and offers new opportunities to investigate the discordances between anatomic and functional outcomes after retinal detachment surgery. Hence, the study aim was to use SD-OCT to compare the postoperative macular recovery between scleral buckling and vitrectomy for macular-off rhegmatogenous retinal detachment. Methods In this retrospective observational case series, we observed 32 patients who underwent scleral buckling surgery (group 1) and 26 patients who underwent pars plana vitrectomy (group 2) as the primary surgery for macula-off rhegmatogenous retinal detachment. OCT was used to examine microstructural changes in the macular area. Results The mean visual acuity improvement was 0.4 ± 0.8 logMAR in group 1 and 0.7 ± 0.9 logMAR in group 2. As detected by SD-OCT, subretinal fluid was present in 26 of the group 1 eyes (81.3%) and 5 of the group 2 eyes (19.2%) at 8 weeks postoperatively. This difference was statistically significant (Fisher’s exact test, P < 0.05). Moreover, detection by SD-OCT revealed epiretinal membranes in 5 of the group 1 eyes (15.6%) and 11 of the group 2 eyes (42.3%), a difference that was statistically significant (Fisher’s exact test, P < 0.05). Conclusions Macular recovery and the mean visual acuity differed between the 2 groups of patients. With the help of SD-OCT, we observed that subretinal fluids could persist for a relatively longer period after scleral buckling. Based on our results, we conclude that primary vitrectomy surgery is a better choice for macular recovery of the macula-off rhegmatogenous retinal detachment. PMID:23587195

  18. Integrating Scleral Buckling, Transscleral Drainage of Subretinal Fluid, Intravitreal Anti-Vascular Endothelial Growth Factor, and Laser Photocoagulation in Stage 3B Coats' Total Retinal Detachment.

    PubMed

    Huang, Ying-Chen; Lai, Chi-Chun; Wu, Wei-Chi

    2016-09-01

    The integration of quadruple therapy in a 13-year-old boy with stage 3B Coats' disease achieved retinal reattachment and visual improvement. Scleral buckling might play a role in retinal detachment in Coats' disease, although it has previously been considered insignificant. Instead of performing vitrectomy and internal drainage with a drainage hole in the retina, less-invasive procedures that do not require retinotomy appear to be beneficial in cases of advanced Coats' disease. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:865-868.].

  19. Planarian Hedgehog/Patched establishes anterior–posterior polarity by regulating Wnt signaling

    PubMed Central

    Yazawa, Shigenobu; Umesono, Yoshihiko; Hayashi, Tetsutaro; Tarui, Hiroshi; Agata, Kiyokazu

    2009-01-01

    Despite long-standing interest, the molecular mechanisms underlying the establishment of anterior–posterior (AP) polarity remain among the unsolved mysteries in metazoans. In the planarians (a family of flatworms), canonical Wnt/β-catenin signaling is required for posterior specification, as it is in many animals. However, the molecular mechanisms regulating the posterior-specific induction of Wnt genes according to the AP polarity have remained unclear. Here, we demonstrate that Hedgehog (Hh) signaling is responsible for the establishment of AP polarity via its regulation of the transcription of Wnt family genes during planarian regeneration. We found that RNAi gene knockdown of Dugesia japonica patched (Djptc) caused ectopic tail formation in the anterior blastema of body fragments, resulting in bipolar-tails regeneration. In contrast, RNAi of hedgehog (Djhh) and gli (Djgli) caused bipolar-heads regeneration. We show that Patched-mediated Hh signaling was crucial for posterior specification, which is established by regulating the transcription of Wnt genes via downstream Gli activity. Moreover, differentiated cells were responsible for the posterior specification of undifferentiated stem cells through Wnt/β-catenin signaling. Surprisingly, Djhh was expressed in neural cells all along the ventral nerve cords (along the AP axis), but not in the posterior blastema of body fragments, where the expression of Wnt genes was induced for posteriorization. We therefore propose that Hh signals direct head or tail regeneration according to the AP polarity, which is established by Hh signaling activity along the body's preexisting nervous system. PMID:20018728

  20. Clinical Characteristics of Posterior and Lateral Semicircular Canal Dehiscence

    PubMed Central

    Spasic, Marko; Trang, Andy; Chung, Lawrance K.; Ung, Nolan; Thill, Kimberly; Zarinkhou, Golmah; Gopen, Quinton S.; Yang, Isaac

    2015-01-01

    The objective of this study was to evaluate the characteristic symptoms of and treatments for lateral semicircular canal dehiscence (LSCD) and posterior semicircular canal dehiscence (PSCD) and its proposed mechanism. A dehiscence acquired in any of the semicircular canals may evoke various auditory symptoms (autophony and inner ear conductive hearing loss) or vestibular symptoms (vertigo, the Tullio phenomenon, and Hennebert sign) by creating a “third mobile window” in the bone that enables aberrant communication between the inner ear and nearby structures. A PubMed search was performed using the keywords lateral, posterior, and semicircular canal dehiscence to identify all relevant cases. Our data suggest that PSCD, although clinically rare, is most likely associated with a high-riding jugular bulb and fibrous dysplasia. Patients may experience auditory manifestations that range from mild conductive to extensive sensorineural hearing loss. LSCD is usually associated with chronic otitis media with cholesteatoma. PMID:26682120

  1. Downregulation of the posterior medial frontal cortex prevents social conformity.

    PubMed

    Klucharev, Vasily; Munneke, Moniek A M; Smidts, Ale; Fernández, Guillén

    2011-08-17

    We often change our behavior to conform to real or imagined group pressure. Social influence on our behavior has been extensively studied in social psychology, but its neural mechanisms have remained largely unknown. Here we demonstrate that the transient downregulation of the posterior medial frontal cortex by theta-burst transcranial magnetic stimulation reduces conformity, as indicated by reduced conformal adjustments in line with group opinion. Both the extent and probability of conformal behavioral adjustments decreased significantly relative to a sham and a control stimulation over another brain area. The posterior part of the medial frontal cortex has previously been implicated in behavioral and attitudinal adjustments. Here, we provide the first interventional evidence of its critical role in social influence on human behavior.

  2. Posterior Hip Pain in an Athletic Population

    PubMed Central

    Frank, Rachel M.; Slabaugh, Mark A.; Grumet, Robert C.; Virkus, Walter W.; Bush-Joseph, Charles A.; Nho, Shane J.

    2010-01-01

    Context: Posterior hip pain is a relatively uncommon but increasingly recognized complaint in the orthopaedic community. Patient complaints and presentations are often vague or nonspecific, making diagnosis and subsequent treatment decisions difficult. The purposes of this article are to review the anatomy and pathophysiology related to posterior hip pain in the athletic patient population. Evidence Acquisition: Data were collected through a thorough review of the literature via a MEDLINE search of all relevant articles between 1980 and 2010. Results: Many patients who complain of posterior hip pain actually have pain referred from another part of the body—notably, the lumbar spine or sacroiliac joint. Treatment options for posterior hip pain are typically nonoperative; however, surgery is warranted in some cases. Conclusions: Recent advancements in the understanding of hip anatomy, pathophysiology, and treatment options have enabled physicians to better diagnosis athletic hip injuries and select patients for appropriate treatment. PMID:23015944

  3. Posterior cruciate ligament (PCL) injury - aftercare

    MedlinePlus

    Adib F, Curtis C, Bienkowski P Micheli LJ. Posterior cruciate ligament sprain. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, ...

  4. Posterior dislocation of the sternoclavicular joint leading to mediastinal compression.

    PubMed

    Jougon, J B; Lepront, D J; Dromer, C E

    1996-02-01

    Dislocations of the sternoclavicular joint are uncommon, and the posterior variety have a potential for considerable morbidity. We report a case with compression of the vital structures within the superior mediastinum. It was a rugby player getting run over by the scrum. The mechanism was an indirect force exerted forward and laterally against the shoulder. The patient complained of pain and dysphagia. A systolic right cervical murmur was heard. Angiography was normal and esophagography showed extrinsic esophageal compression. Surgical reduction was performed because there was a slight pneumomediastinum on the computed tomography. This case report demonstrates the mechanism, complications, and treatment of such a lesion.

  5. Gibbs Sampling for Marginal Posterior Expectations

    DTIC Science & Technology

    1991-11-19

    Achcar and Smith (1989) shows that performance of the Laplace method is often very sensitive to parametrization. Morris (1988) offers expansions based on...Berkeley Symp. 1, 453-468. Lindley, D.V. (1980). "Approximate Bayesian Methods" in Bayesian Statistics, J.M. Bernardo, M.H. DeGroot , D.V. Lindley...A.F.M. Smith, University Press, Valencia, Spain. Morris , C. "Approximating Posterior Distributions and Posterior Moments" In: Bayesian Statistics 3, J.M

  6. [Posterior cortical atrophy (Benson-syndrome)].

    PubMed

    Rózsa, Anikó; Szilvássy, Ildikó; Kovács, Krisztina; Boór, Krisztina; Gács, Gyula

    2010-01-30

    We present the characteristics of posterior cortical atrophy--a very rare cortical dementia--in a 69 year old woman's case. Our patient's symptoms began with a visual problem which was initially explained by ophthalmological disorder. After neurological exam visual agnosia was diagnosed apart from other cognitive disorder (alexia without agraphia, acalculia, prosopagnosia, constructional disorder, clock-time recognition disorder, dressing apraxia, visuospatial disorientation). The brain MRI showed bilateral asymmetric parieto-occipital atrophy which is characteristic of posterior cortical atrophy.

  7. Vertigo due to posterior circulation stroke.

    PubMed

    Kim, Ji Soo; Lee, Hyung

    2013-07-01

    Stroke in the distribution of the posterior circulation may present as acute onset spontaneous vertigo and imbalance. Although vertigo due to posterior circulation stroke is usually associated with other neurologic symptoms or signs, small infarcts in the cerebellum or brainstem can present with vertigo without other localizing symptoms. Approximately 17% of patients with isolated posterior inferior cerebellar artery territory infarction presented with isolated vertigo, nystagmus, and postural unsteadiness. A head impulse test can differentiate acute isolated vertigo associated with cerebellar stroke from more benign disorders involving the inner ear. Sometimes acute isolated audiovestibular loss can be the initial symptom of impending posterior circulation ischemic stroke (particularly within the territory of the anterior inferior cerebellar artery). In this case, evaluation of isolated audiovestibular loss may prevent the progression of acute vertigo and hearing loss into more widespread areas of infarction in the posterior circulation. In this article, the clinical syndromes and signs of acute vestibular syndrome due to posterior circulation stroke involving the brainstem and cerebellum are summarized.

  8. Posterior urethral polyp with type I posterior urethral valves: a rare association in a neonate.

    PubMed

    Kesan, Krushnakumar V; Gupta, Rahul Kumar; Kothari, Paras; Gupta, Abhaya; Mudkhedkar, Kedar; Kamble, Ravikiran; Dikshit, K Vishesh

    2014-06-01

    Urethral polyp is a rare cause of bladder outlet obstruction, voiding dysfunction, and hematuria in the pediatric age group. Urethral polyps are rarely associated with other congenital urinary tract anomalies. In this study, we report a case of solitary posterior urethral polyp with type I posterior urethral valve in a 7-day-old neonate presented with urinary retention and deranged renal function. The polyp was diagnosed on cystoscopy. Transurethral resection of the polyp with posterior urethral valve fulguration was performed. Pathologic assessment revealed a fibroepithelial lesion, which was consistent with congenital posterior urethral polyp.

  9. Hox Genes Promote Neuronal Subtype Diversification through Posterior Induction in Caenorhabditis elegans.

    PubMed

    Zheng, Chaogu; Diaz-Cuadros, Margarete; Chalfie, Martin

    2015-11-04

    Although Hox genes specify the differentiation of neuronal subtypes along the anterior-posterior axis, their mode of action is not entirely understood. Using two subtypes of the touch receptor neurons (TRNs) in C. elegans, we found that a "posterior induction" mechanism underlies the Hox control of terminal neuronal differentiation. The anterior subtype maintains a default TRN state, whereas the posterior subtype undergoes further morphological and transcriptional specification induced by the posterior Hox proteins, mainly EGL-5/Abd-B. Misexpression of the posterior Hox proteins transformed the anterior TRN subtype toward a posterior identity both morphologically and genetically. The specification of the posterior subtype requires EGL-5-induced repression of TALE cofactors, which antagonize EGL-5 functions, and the activation of rfip-1, a component of recycling endosomes, which mediates Hox activities by promoting subtype-specific neurite outgrowth. Finally, EGL-5 is required for subtype-specific circuit formation by acting in both the sensory neuron and downstream interneuron to promote functional connectivity.

  10. Aspects of treatment for posterior heel pain in young athletes

    PubMed Central

    Elengard, Thomas; Karlsson, Jón; Silbernagel, Karin Grävare

    2010-01-01

    Posterior heel pain occurs in young athletes involved in running and jumping. Due to the pain, the child often limits his/her physical activity level, with a possible negative effect on health and well-being. Although numerous research studies have examined the cause and treatment of heel and Achilles tendon pain in adults, there are no randomized clinical trials on treatment in children and adolescents. Therefore, there is limited evidence for how to treat young athletes with this type of complaint. The purpose of this review was to analyze critically and summarize the literature in regards to the cause and treatment of posterior heel pain in young athletes. The various diagnoses and clinical presentations relating to posterior heel and Achilles tendon pain are discussed. The theory and mechanism behind various recommended treatment strategies are also reviewed in the context of use in the young athlete. In summary, it is important to perform a thorough evaluation of each young athlete with heel pain to determine the appropriate diagnosis and to treat the deficits found and allow for a gradual progression to training. However, the recommendations at this time are based on clinical experience and a few retrospective studies, so further well designed prospective studies with validated outcome measures are urgently needed for the young athlete. PMID:24198561

  11. Anterior and posterior centers jointly regulate Bombyx embryo body segmentation.

    PubMed

    Nakao, Hajime

    2012-11-15

    Insect embryo segmentation is largely divided into long and short germ types. In the long germ type, each segment primordium is represented on a large embryonic rudiment of the blastoderm, and segmental patterning occurs nearly simultaneously in the syncytium. In the short germ type, however, only anterior segments are represented in the small embryonic rudiment, usually located on the egg posterior, and the rest of the segments are added sequentially from the posterior growth zone in a cellular context. The long germ type is thought to have evolved from the short germ type. It is proposed that this transition, which appears to have occurred multiple times over the course of evolution, was realized through the acquisition of a localized anterior instruction center. Here, I examined the early segmentation process in the silkmoth Bombyx mori, a lepidopteran insect, in which the mechanisms of anterior-posterior (AP) axis formation have not been well analyzed. In this insect, both the long germ and short germ features have been reported. The mRNAs for two key genes involved in insect AP axis formation, orthodenticle (Bm-otd) and caudal (Bm-cad), are localized maternally in the germ anlage, where they act as anterior and posterior instruction centers, respectively. RNAi studies indicate that, while Bm-cad affects the formation of all the even skipped (Bm-eve) stripes, there is also anterior Bm-eve stripe formation activity that involves Bm-otd. Thus, there is redundancy in Bm-eve stripe formation activity that must be coordinated. Some genetic interactions, identified either experimentally or hypothetically, are also introduced, which might enable robust AP formation in this organism.

  12. Posterior cruciate ligament removal contributes to abnormal knee motion during posterior stabilized total knee arthroplasty.

    PubMed

    Cromie, Melinda J; Siston, Robert A; Giori, Nicholas J; Delp, Scott L

    2008-11-01

    Abnormal anterior translation of the femur on the tibia has been observed in mid flexion (20-60 degrees ) following posterior stabilized total knee arthroplasty. The underlying biomechanical causes of this abnormal motion remain unknown. The purpose of this study was to isolate the effects of posterior cruciate ligament removal on knee motion after total knee arthroplasty. We posed two questions: Does removing the posterior cruciate ligament introduce abnormal anterior femoral translation? Does implanting a posterior stabilized prosthesis change the kinematics from the cruciate deficient case? Using a navigation system, we measured passive knee kinematics of ten male osteoarthritic patients during surgery after initial exposure, after removing the anterior cruciate ligament, after removing the posterior cruciate ligament, and after implanting the prosthesis. Passively flexing and extending the knee, we calculated anterior femoral translation and the flexion angle at which femoral rollback began. Removing the posterior cruciate ligament doubled anterior translation (from 5.1 +/- 4.3 mm to 10.4 +/- 5.1 mm) and increased the flexion angle at which femoral rollback began (from 31.2 +/- 9.6 degrees to 49.3 +/- 7.3 degrees). Implanting the prosthesis increased the amount of anterior translation (to 16.1 +/- 4.4 mm), and did not change the flexion angle at which femoral rollback began. Abnormal anterior translation was observed in low and mid flexion (0-60 degrees) after removing the posterior cruciate ligament, and normal motion was not restored by the posterior stabilized prosthesis.

  13. A shift in anterior-posterior positional information underlies the fin-to-limb evolution.

    PubMed

    Onimaru, Koh; Kuraku, Shigehiro; Takagi, Wataru; Hyodo, Susumu; Sharpe, James; Tanaka, Mikiko

    2015-08-18

    The pectoral fins of ancestral fishes had multiple proximal elements connected to their pectoral girdles. During the fin-to-limb transition, anterior proximal elements were lost and only the most posterior one remained as the humerus. Thus, we hypothesised that an evolutionary alteration occurred in the anterior-posterior (AP) patterning system of limb buds. In this study, we examined the pectoral fin development of catshark (Scyliorhinus canicula) and revealed that the AP positional values in fin buds are shifted more posteriorly than mouse limb buds. Furthermore, examination of Gli3 function and regulation shows that catshark fins lack a specific AP patterning mechanism, which restricts its expression to an anterior domain in tetrapods. Finally, experimental perturbation of AP patterning in catshark fin buds results in an expansion of posterior values and loss of anterior skeletal elements. Together, these results suggest that a key genetic event of the fin-to-limb transformation was alteration of the AP patterning network.

  14. Fundus autofluorescence imaging in posterior uveitis.

    PubMed

    Durrani, Khayyam; Foster, C Stephen

    2012-01-01

    Although the phenomenon of fundus autofluorescence has been known for decades, it has only recently been recognized as a measure of retinal pigment epithelial function and health. Characteristic fundus autofluorescence patterns have been described in eyes affected by inflammation of the posterior segment, and these patterns have provided insights into the pathogenesis of posterior uveitis entities. In addition, preliminary data indicate that fundus autofluorescence characteristics may serve as markers of disease activity, allow prediction of visual prognosis, and may help determine the adequacy of therapy. We provide an overview of the current state of fundus autofluorescence imaging technology and review our current knowledge of fundus autoflourescence findings and their clinical use in the posterior uveitis entities.

  15. Left hand tactile agnosia after posterior callosal lesion.

    PubMed

    Balsamo, Maddalena; Trojano, Luigi; Giamundo, Arcangelo; Grossi, Dario

    2008-09-01

    We report a patient with a hemorrhagic lesion encroaching upon the posterior third of the corpus callosum but sparing the splenium. She showed marked difficulties in recognizing objects and shapes perceived through her left hand, while she could appreciate elementary sensorial features of items tactually presented to the same hand flawlessly. This picture, corresponding to classical descriptions of unilateral associative tactile agnosia, was associated with finger agnosia of the left hand. This very unusual case report can be interpreted as an instance of disconnection syndrome, and allows a discussion of mechanisms involved in tactile object recognition.

  16. Reversible cortical blindness: posterior reversible encephalopathy syndrome.

    PubMed

    Bandyopadhyay, Sabyasachi; Mondal, Kanchan Kumar; Das, Somnath; Gupta, Anindya; Biswas, Jaya; Bhattacharyya, Subir Kumar; Biswas, Gautam

    2010-11-01

    Cortical blindness is defined as visual failure with preserved pupillary reflexes in structurally intact eyes due to bilateral lesions affecting occipital cortex. Bilateral oedema and infarction of the posterior and middle cerebral arterial territory, trauma, glioma and meningioma of the occipital cortex are the main causes of cortical blindness. Posterior reversible encephalopathy syndrome (PRES) refers to the reversible subtype of cortical blindness and is usually associated with hypertension, diabetes, immunosuppression, puerperium with or without eclampsia. Here, 3 cases of PRES with complete or partial visual recovery following treatment in 6-month follow-up are reported.

  17. Posterior cortical atrophy: a brief review.

    PubMed

    Kirshner, Howard S; Lavin, Patrick J M

    2006-11-01

    Posterior cortical atrophy is a striking clinical syndrome in which a dementing illness begins with visual symptoms. Initially, the problem may seem to be loss of elementary vision, but over time the patient develops features of visual agnosia, topographical difficulty, optic ataxia, simultanagnosia, ocular apraxia (Balint's syndrome), alexia, acalculia, right-left confusion, and agraphia (Gerstmann's syndrome), and later a more generalized dementia. Occasional patients have visual hallucinations and signs of Parkinson's disease or Lewy body dementia. A number of different neuropathologic disorders are associated with posterior cortical atrophy.

  18. Treatment rationale of fractured posterior teeth.

    PubMed

    Silvestri, A R; Singh, I

    1978-11-01

    The four types of fractures most frequently encountered in posterior teeth--obliquely directed complete fractures, vertically directed complete fractures, obliquely directed incomplete fractures, and vertically directed incomplete fractures--have been described. A detailed treatment approach for each type has been presented.

  19. Posterior Predictive Model Checking in Bayesian Networks

    ERIC Educational Resources Information Center

    Crawford, Aaron

    2014-01-01

    This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

  20. Posterior Probabilities for a Consensus Ordering.

    ERIC Educational Resources Information Center

    Fligner, Michael A.; Verducci, Joseph S.

    1990-01-01

    The concept of consensus ordering is defined, and formulas for exact and approximate posterior probabilities for consensus ordering are developed under the assumption of a generalized Mallows' model with a diffuse conjugate prior. These methods are applied to a data set concerning 98 college students. (SLD)

  1. Complicated posterior capsulorhexis: aetiology, management, and outcome

    PubMed Central

    Van Cauwenberge, F.; Rakic, J.; Galand, A.

    1997-01-01

    BACKGROUND—A 1 year retrospective analysis of 650 patients, who underwent a posterior capsulorhexis on their intact capsules, was performed to examine the incidence of complications, their aetiologies, and the outcome.
METHODS—Data were analysed on 32 patients with complicated capsulorhexis for type of surgery, preoperative and postoperative factors, and relative risk factors for vitreous issue.
RESULTS—There were six patients with vitreous loss. The posterior capsulorhexis was uncontrolled in 14 cases and difficult to perform in 12 cases. Implantation into the capsular bag was possible in all cases. Systemic vascular hazard and old age (over 80 years) were found to be statistically significant risk factors for vitreous loss (p=0.002 and p=0.03 respectively). The mean follow up was 13.5 months (range 4-25 months). One patient developed a retinal detachment and two had a transient clinical cystoid macular oedema. Visual acuity of ≥ 20/40 was obtained in 93% of the patients.
CONCLUSION—Loss of control of the posterior capsulorhexis has a low incidence but can lead to serious problems during surgery. A good knowledge of the technique is necessary to complete the procedure with a posterior capsulorhexis of the optimum size without vitreous loss.

 PMID:9135382

  2. Subspecialization in the human posterior medial cortex

    PubMed Central

    Bzdok, Danilo; Heeger, Adrian; Langner, Robert; Laird, Angela R.; Fox, Peter T.; Palomero-Gallagher, Nicola; Vogt, Brent A.; Zilles, Karl; Eickhoff, Simon B.

    2014-01-01

    The posterior medial cortex (PMC) is particularly poorly understood. Its neural activity changes have been related to highly disparate mental processes. We therefore investigated PMC properties with a data-driven exploratory approach. First, we subdivided the PMC by whole-brain coactivation profiles. Second, functional connectivity of the ensuing PMC regions was compared by task-constrained meta-analytic coactivation mapping (MACM) and task-unconstrained resting-state correlations (RSFC). Third, PMC regions were functionally described by forward/reverse functional inference. A precuneal cluster was mostly connected to the intraparietal sulcus, frontal eye fields, and right temporo-parietal junction; associated with attention and motor tasks. A ventral posterior cingulate cortex (PCC) cluster was mostly connected to the ventromedial prefrontal cortex and middle left inferior parietal cortex (IPC); associated with facial appraisal and language tasks. A dorsal PCC cluster was mostly connected to the dorsomedial prefrontal cortex, anterior/posterior IPC, posterior midcingulate cortex, and left dorsolateral prefrontal cortex; associated with delay discounting. A cluster in the retrosplenial cortex was mostly connected to the anterior thalamus and hippocampus. Furthermore, all PMC clusters were congruently coupled with the default mode network according to task-constrained but not task-unconstrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. PMID:25462801

  3. Fuchs's heterochromic cyclitis and posterior capsulotomy.

    PubMed Central

    Roussel, T J; Coster, D J

    1985-01-01

    We report a case of intractable glaucoma following an uncomplicated secondary posterior capsulotomy in a 48-year-old male with Fuchs's heterochromic cyclitis. The patient had been free of inflammation and glaucoma since cataract extraction 27 years previously. We also report the results of phenotypic analysis of lymphocytes removed from the anterior chamber. Images PMID:3859323

  4. Conservative treatment of a tibialis posterior strain in a novice triathlete: a case report

    PubMed Central

    Howitt, Scott; Jung, Sarah; Hammonds, Nicole

    2009-01-01

    Objective To detail the progress of a novice triathlete with an unusual mechanism of a tibialis posterior strain who underwent successful conservative treatment and rehabilitation. Tibialis posterior tendon dysfunction will be discussed as it relates to the case. Clinical Features The clinical features of tibialis posterior dysfunction are swelling and edema posterior to the medial malleolus with pain and an inability to weight bear. This injury may occur in endurance athletes such as triathletes, most often occurring during running. Intervention and Outcome The conservative treatment approach used in this case consisted of medical acupuncture with electrical stimulation, Graston Technique© a soft tissue instrument assisted mobilization technique, Active Release Technique®, ultrasound therapy with Traumeel, and rehabilitation. Gait analysis and orthotic prescription was completed when the patient was ready to return to play. Outcome measures included subjective pain rating and return to pre-injury activities. Objective measures included swelling and manual muscle testing. Conclusion A novice triathlete with a grade I tibialis posterior strain was quickly relieved of his symptoms and able to return to his triathlon training with conservative treatment. Practitioners treating this type of injury could consider including the soft tissue techniques, modalities and rehabilitation employed in our case for other patients with lower leg strains and/or tibialis posterior dysfunction. PMID:19421350

  5. Mapping 3D Strains with Ultrasound Speckle Tracking: Method Validation and Initial Results in Porcine Scleral Inflation.

    PubMed

    Cruz Perez, Benjamin; Pavlatos, Elias; Morris, Hugh J; Chen, Hong; Pan, Xueliang; Hart, Richard T; Liu, Jun

    2016-07-01

    This study aimed to develop and validate a high frequency ultrasound method for measuring distributive, 3D strains in the sclera during elevations of intraocular pressure. A 3D cross-correlation based speckle-tracking algorithm was implemented to compute the 3D displacement vector and strain tensor at each tracking point. Simulated ultrasound radiofrequency data from a sclera-like structure at undeformed and deformed states with known strains were used to evaluate the accuracy and signal-to-noise ratio (SNR) of strain estimation. An experimental high frequency ultrasound (55 MHz) system was built to acquire 3D scans of porcine eyes inflated from 15 to 17 and then 19 mmHg. Simulations confirmed good strain estimation accuracy and SNR (e.g., the axial strains had less than 4.5% error with SNRs greater than 16.5 for strains from 0.005 to 0.05). Experimental data in porcine eyes showed increasing tensile, compressive, and shear strains in the posterior sclera during inflation, with a volume ratio close to one suggesting near-incompressibility. This study established the feasibility of using high frequency ultrasound speckle tracking for measuring 3D tissue strains and its potential to characterize physiological deformations in the posterior eye.

  6. [Manual rotation of occiput posterior presentation].

    PubMed

    Le Ray, C; Goffinet, F

    2011-10-01

    Delivery in occiput posterior position is associated with a higher risk of cesarean section, operative vaginal delivery and severe perineal tears. We report the technic of manual rotation described by Tarnier and Chantreuil and used daily in our maternity center. Only five studies were published on this topic; all of them demonstrate that manual rotation decreases the risk of cesarean section. Moreover, it could decrease the risk of prolonged second stage, chorioamnionitis and third and fourth degree tears in comparison with expectant management. However, manual rotation is associated with a two-fold higher risk of cervical and vaginal lacerations. Manual rotation performed with an adequate technic is an efficient and safe manœuvre to avoid complications associated with occiput posterior vaginal delivery.

  7. Acute traumatic posterior elbow dislocation in children.

    PubMed

    Lieber, Justus; Zundel, Sabine M; Luithle, Tobias; Fuchs, Jörg; Kirschner, Hans-Joachim

    2012-09-01

    Traumatic posterior dislocation of the elbow is often associated with significant morbidity and incomplete recovery. The aim of this study was to retrospectively analyse the outcome of 33 children (median age 10.8 years). Patients underwent reduction and assessment of stability under general anaesthesia. Pure dislocations (n=10) were immobilized, whereas unstable fractures (n=23) were stabilized. Refixation of ligaments was performed if stability was not achieved by fracture stabilization alone. Immobilization was continued for 26 (pure dislocations) or 35 days (associated injuries), respectively. Results were excellent (n=9) or good (n=1) after pure dislocation. Results were excellent (n=15), good (n=7) or poor (n=1) in children with associated injuries. Accurate diagnosis, concentric stable reduction of the elbow as well as stable osteosynthesis of displaced fractures are associated with good results in children with acute posterior elbow dislocations.

  8. Posterior tibial nerve lesions in ankle arthroscopy.

    PubMed

    Cugat, Ramon; Ares, Oscar; Cuscó, Xavier; Garcia, Montserrat; Samitier, Gonzalo; Seijas, Roberto

    2008-05-01

    Ankle arthroscopy provides a minimally invasive approach to the diagnosis and treatment of certain ankle disorders. Neurological complications resulting from ankle arthroscopy have been well documented in orthopaedic and podiatric literature. Owing to the superficial location of the ankle joint and the abundance of overlying periarticular neurovascular structures, complications reported in ankle arthroscopy are greater than those reported for other joints. In particular, all reported neurovascular injuries following ankle arthroscopy have been the direct result of distractor pin or portal placement. The standard posteromedial portal has recognized risks because of the proximity of the posterior neurovascular structures. There can be considerable variability in the course of these portals and their proximity to the neurovascular structures. We found one report of intra-articular damage to the posterior tibial nerve as a result of ankle arthroscopy in the English-language literature and we report this paper as a second case described in the literature.

  9. Posterior composite restoration update: focus on factors influencing form and function

    PubMed Central

    Bohaty, Brenda S; Ye, Qiang; Misra, Anil; Sene, Fabio; Spencer, Paulette

    2013-01-01

    Restoring posterior teeth with resin-based composite materials continues to gain popularity among clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite restorations, however, have higher failure rates, more recurrent caries, and increased frequency of replacement. Investigators across the globe are researching new materials and techniques that will improve the clinical performance, handling characteristics, and mechanical and physical properties of composite resin restorative materials. Despite such attention, large to moderate posterior composite restorations continue to have a clinical lifetime that is approximately one-half that of the dental amalgam. While there are numerous recommendations regarding preparation design, restoration placement, and polymerization technique, current research indicates that restoration longevity depends on several variables that may be difficult for the dentist to control. These variables include the patient’s caries risk, tooth position, patient habits, number of restored surfaces, the quality of the tooth–restoration bond, and the ability of the restorative material to produce a sealed tooth–restoration interface. Although clinicians tend to focus on tooth form when evaluating the success and failure of posterior composite restorations, the emphasis must remain on advancing our understanding of the clinical variables that impact the formation of a durable seal at the restoration–tooth interface. This paper presents an update of existing technology and underscores the mechanisms that negatively impact the durability of posterior composite restorations in permanent teeth. PMID:23750102

  10. CTCF-mediated Chromatin Loop for the Posterior Hoxc Gene Expression in MEF Cells.

    PubMed

    Min, Hyehyun; Kong, Kyoung-Ah; Lee, Ji-Yeon; Hong, Chang-Pyo; Seo, Seong-Hye; Roh, Tae-Young; Bae, Sun Sik; Kim, Myoung Hee

    2016-06-01

    Modulation of chromatin structure has been proposed as a molecular mechanism underlying the spatiotemporal collinear expression of Hox genes during development. CCCTC-binding factor (CTCF)-mediated chromatin organization is now recognized as a crucial epigenetic mechanism for transcriptional regulation. Thus, we examined whether CTCF-mediated chromosomal conformation is involved in Hoxc gene expression by comparing wild-type mouse embryonic fibroblast (MEF) cells expressing anterior Hoxc genes with Akt1 null MEFs expressing anterior as well as posterior Hoxc genes. We found that CTCF binding between Hoxc11 and -c12 is important for CTCF-mediated chromosomal loop formation and concomitant posterior Hoxc gene expression. Hypomethylation at this site increased CTCF binding and recapitulated the chromosomal conformation and posterior Hoxc gene expression patterns observed in Akt1 null MEFs. From this work we found that CTCF at the C12|11 does not function as a barrier/boundary, instead let the posterior Hoxc genes switch their interaction from inactive centromeric to active telomeric genomic niche, and concomitant posterior Hoxc gene expression. Although it is not clear whether CTCF affects Hoxc gene expression solely through its looping activity, CTCF-mediated chromatin structural modulation could be an another tier of Hox gene regulation during development. © 2016 IUBMB Life, 68(6):436-444, 2016.

  11. Progressive visual agnosia with posterior cortical atrophy.

    PubMed

    Mizuno, M; Sartori, G; Liccione, D; Battelli, L; Campo, R

    1996-05-01

    A patient of posterior cortical atrophy characterized by early signs of progressive visual agnosia documented by repeated neuropsychological tests, is reported. SPECT and MRI findings showed left unilateral parieto-occipital involvement in the earlier stage. A PET study executed eight months later showed bilateral parieto-occipital hypometabolism, but predominantly in the left hemisphere. This suggests that the degeneration may have developed asymmetrically, progressing from left unilateral to bilateral.

  12. Endoscopic posterior interhemispheric complete corpus callosotomy.

    PubMed

    Sood, Sandeep; Asano, Eishi; Altinok, Deniz; Luat, Aimee

    2016-12-01

    Traditionally corpus callosotomy is done through a craniotomy centered at the coronal suture, with the aid of a microscope. This involves dissecting through the interhemispheric fissure below the falx to reach the corpus callosum. The authors describe a posterior interhemispheric approach to complete corpus callosotomy with an endoscope, which bypasses the need to perform interhemispheric dissection because the falx is generally close to the corpus callosum in this region.

  13. Iris fixation of posterior chamber intraocular lenses.

    PubMed

    Yazdani-Abyaneh, Alireza; Djalilian, Ali R; Fard, Masoud Aghsaei

    2016-12-01

    We introduce a technique for iris fixation of a posterior chamber intraocular lens (IOL) in which most of the procedure is done outside the eye. This minimizes intraocular manipulation, maximizes corneal endothelial preservation, and avoids the risk for IOL drop into the vitreous cavity intraoperatively. The IOL is fixated to the most peripheral part of the iris, resulting in a rounder pupil. Sutures are placed at exact positions on the haptics, resulting in a well-centered IOL.

  14. Cervical disc hernia operations through posterior laminoforaminotomy

    PubMed Central

    Yolas, Coskun; Ozdemir, Nuriye Guzin; Okay, Hilmi Onder; Kanat, Ayhan; Senol, Mehmet; Atci, Ibrahim Burak; Yilmaz, Hakan; Coban, Mustafa Kemal; Yuksel, Mehmet Onur; Kahraman, Umit

    2016-01-01

    Objective: The most common used technique for posterolateral cervical disc herniations is anterior approach. However, posterior cervical laminotoforaminomy can provide excellent results in appropriately selected patients with foraminal stenosis in either soft disc prolapse or cervical spondylosis. The purpose of this study was to present the clinical outcomes following posterior laminoforaminotomy in patients with radiculopathy. Materials and Methods: We retrospectively evaluated 35 patients diagnosed with posterolateral cervical disc herniation and cervical spondylosis with foraminal stenosis causing radiculopathy operated by the posterior cervical keyhole laminoforaminotomy between the years 2010 and 2015. Results: The file records and the radiographic images of the 35 patients were assessed retrospectively. The mean age was 46.4 years (range: 34-66 years). Of the patients, 19 were males and 16 were females. In all of the patients, the neurologic deficit observed was radiculopathy. The posterolaterally localized disc herniations and the osteophytic structures were on the left side in 18 cases and on the right in 17 cases. In 10 of the patients, the disc level was at C5-6, in 18 at C6-7, in 2 at C3-4, in 2 at C4-5, in 1 at C7-T1, in 1 patient at both C5-6 and C6-7, and in 1 at both C4-5 and C5-6. In 14 of these 35 patients, both osteophytic structures and protruded disc herniation were present. Intervertebral foramen stenosis was present in all of the patients with osteophytes. Postoperatively, in 31 patients the complaints were relieved completely and four patients had complaints of neck pain and paresthesia radiating to the arm (the success of operation was 88.5%). On control examinations, there was no finding of instability or cervical kyphosis. Conclusion: Posterior cervical laminoforaminotomy is an alternative appropriate choice in both cervical soft disc herniations and cervical stenosis. PMID:27217655

  15. Posterior fossa syndrome—a narrative review

    PubMed Central

    Wahab, Salima S.; Hettige, Samantha; Mankad, Kshtij

    2016-01-01

    Posterior fossa syndrome (PFS), or cerebellar mutism syndrome (CMS), is a collection of neurological symptoms that occur following surgical resection of a posterior fossa tumour, and is characterised by either a reduction or an absence of speech. Some authors suggest that CM is only one symptom of the CMS complex that also includes ataxia, hypotonia and irritability as well as cranial nerve deficits, neurobehavioral changes and urinary retention or incontinence. It is seen almost exclusively in children. In 1985 Rekate et al. published the first work describing CM as a clinical entity, occurring as a consequence of bilateral cerebellar injury. Other associated symptoms include visual impairment, altered mood, impaired swallowing and significant gross and fine motor deficits. The effects of this can have a devastating impact on both the patient and their carers, posing a significant clinical challenge to neurorehabilitation services. The reported incidence was between 8% and 31% of children undergoing surgery for posterior fossa tumour. The underlying pathologies include vasospasm, oedema, and axonal/neuronal injury. Neuroimaging has contributed to a better understanding of the anatomical location of postoperative injury. There have been a number of suggestions for treatment interventions for PFS. However, apart from some individual reports, there have been no clinical trials indicating possible benefit. Occupational therapy, speech and language therapy, as well as neurocognitive support, contribute to the recovery of these patients. PMID:27942479

  16. Electrocardiographic diagnosis of remote posterior wall myocardial infarction using unipolar posterior lead V9

    SciTech Connect

    Rich, M.W.; Imburgia, M.; King, T.R.; Fischer, K.C.; Kovach, K.L. )

    1989-09-01

    The accuracy of four electrocardiographic criteria for diagnosing remote posterior myocardial infarction was assessed prospectively in 369 patients undergoing exercise treadmill testing with thallium scintigraphy. Criteria included the following: (1) R-wave width greater than or equal to 0.04 s and R-wave greater than or equal to S-wave in V1; (2) R-wave greater than or equal to S-wave in V2; (3) T-wave voltage in V2 minus V6 greater than or equal to 0.38 mV (T-wave index); (4) Q-wave greater than or equal to 0.04 s in left paraspinal lead V9. Twenty-seven patients (7.3 percent) met thallium criteria for posterior myocardial infarction, defined as a persistent perfusion defect in the posterobase of the left ventricle. Sensitivities for the four criteria ranged from 4 to 56 percent, and specificities ranged from 64 to 99 percent. Posterior paraspinal lead V9 provided the best overall predictive accuracy (94 percent), positive predictive value (58 percent), and ability to differentiate patients with and without posterior myocardial infarction of any single criterion (p less than .0001). Combining the T-wave index with lead V9 further enhanced the diagnostic yield: the sensitivity for detecting posterior infarction by at least one of these criteria was 78 percent, and when both criteria were positive, specificity was 98.5 percent. It is concluded that a single, unipolar posterior lead in the V9 position is superior to standard 12-lead electrocardiographic criteria in diagnosing remote posterior myocardial infarction, and that combining V9 with the T-wave index maximizes the diagnostic yield.

  17. Posterior Cerebral Artery Insufficiency in Pediatric Moyamoya Disease

    PubMed Central

    Lee, Ji Yeoun; Kim, Seung-Ki; Phi, Ji Hoon

    2015-01-01

    The majority of clinical studies on moyamoya disease (MMD) have focused on anterior circulation. The disease involvement of posterior circulation in MMD, mainly in the posterior cerebral artery (PCA), has been mentioned since the early 1980s, and it has been repeatedly emphasized as one of the most important factors related to poor prognosis in MMD. However, its clinical features and outcome have only been elucidated during the last few years. In this review, the angiographic definition of PCA stenosis is summarized. The clinical features are elucidated as being either early-onset or delayed-onset, according to the time of PCA stenosis diagnosis in reference to the anterior circulation revascularization surgeries. The surgical strategy and hypothesis on the mechanism of PCA stenosis is also briefly mentioned. It appears that some MMD patients may show PCA stenosis during the early or late course of the disease and that the presenting symptoms may vary. Because the hemodynamic compromise caused by PCA stenosis may respond well to surgical treatment, clinicians should be aware of the condition, especially during follow-up of MMD patients. PMID:26180612

  18. The right posterior paravermis and the control of language interference

    PubMed Central

    Filippi, Roberto; Richardson, Fiona M.; Dick, Frederic; Leech, Robert; Green, David W.; Thomas, Michael S.C.; Price, Cathy J.

    2011-01-01

    Auditory and written language in humans' comprehension necessitates attention to the message of interest and suppression of interference from distracting sources. Investigating the brain areas associated with the control of interference is challenging because it is inevitable that activation of the brain regions that control interference co-occurs with activation related to interference per se. To isolate the mechanisms that control verbal interference, we used a combination of structural and functional imaging techniques in Italian and German participants who spoke English as a second language. First, we searched structural MRI images of Italian participants for brain regions where brain structure correlated with the ability to suppress interference from the unattended dominant language (Italian) while processing heard sentences in their weaker language (English). This revealed an area in the posterior paravermis of the right cerebellum where grey matter density was higher in individuals who were better at controlling verbal interference. Second, we found functional activation in the same region when our German participants made semantic decisions on written English words in the presence of interference from unrelated words in their dominant language (German). This combination of structural and functional imaging therefore highlights the contribution of the right posterior paravermis to the control of verbal interference. We suggest that the importance of this region for language processing has previously been missed because most fMRI studies limit the field of view to increase sensitivity; with the lower part of the cerebellum being the most likely region to be excluded. PMID:21775616

  19. Decrease of Prefrontal-Posterior EEG Coherence: Loose Control during Social-Emotional Stimulation

    ERIC Educational Resources Information Center

    Reiser, Eva M.; Schulter, Gunter; Weiss, Elisabeth M.; Fink, Andreas; Rominger, Christian; Papousek, Ilona

    2012-01-01

    In two experiments we aimed to investigate if individual differences in state-dependent decreases or increases of EEG coherence between prefrontal and posterior cortical regions may be indicative of a mechanism modulating the impact social-emotional information has on an individual. Two independent samples were exposed to an emotional stimulation…

  20. The Role of the Right Posterior Parietal Cortex in Temporal Order Judgment

    ERIC Educational Resources Information Center

    Woo, Sung-Ho; Kim, Ki-Hyun; Lee, Kyoung-Min

    2009-01-01

    Perceived order of two consecutive stimuli may not correspond to the order of their physical onsets. Such a disagreement presumably results from a difference in the speed of stimulus processing toward central decision mechanisms. Since previous evidence suggests that the right posterior parietal cortex (PPC) plays a role in modulating the…

  1. The development of posterior probability models in risk-based integrity modeling.

    PubMed

    Thodi, Premkumar N; Khan, Faisal I; Haddara, Mahmoud R

    2010-03-01

    There is a need for accurate modeling of mechanisms causing material degradation of equipment in process installation, to ensure safety and reliability of the equipment. Degradation mechanisms are stochastic processes. They can be best described using risk-based approaches. Risk-based integrity assessment quantifies the level of risk to which the individual components are subjected and provides means to mitigate them in a safe and cost-effective manner. The uncertainty and variability in structural degradations can be best modeled by probability distributions. Prior probability models provide initial description of the degradation mechanisms. As more inspection data become available, these prior probability models can be revised to obtain posterior probability models, which represent the current system and can be used to predict future failures. In this article, a rejection sampling-based Metropolis-Hastings (M-H) algorithm is used to develop posterior distributions. The M-H algorithm is a Markov chain Monte Carlo algorithm used to generate a sequence of posterior samples without actually knowing the normalizing constant. Ignoring the transient samples in the generated Markov chain, the steady state samples are rejected or accepted based on an acceptance criterion. To validate the estimated parameters of posterior models, analytical Laplace approximation method is used to compute the integrals involved in the posterior function. Results of the M-H algorithm and Laplace approximations are compared with conjugate pair estimations of known prior and likelihood combinations. The M-H algorithm provides better results and hence it is used for posterior development of the selected priors for corrosion and cracking.

  2. Reduced modulation of scanpaths in response to task demands in posterior cortical atrophy.

    PubMed

    Shakespeare, Timothy J; Pertzov, Yoni; Yong, Keir X X; Nicholas, Jennifer; Crutch, Sebastian J

    2015-02-01

    scene perception abilities in posterior cortical atrophy and offers insights into the mechanisms by which high-level cognitive schemes interact with low-level perception.

  3. Unilateral abducens and bilateral facial nerve palsies associated with posterior fossa exploration surgery

    PubMed Central

    Khalil, Ayman; Clerkin, James; Mandiwanza, Tafadzwa; Green, Sandra; Javadpour, Mohsen

    2016-01-01

    Multiple cranial nerves palsies following a posterior fossa exploration confined to an extradural compartment is a rare clinical presentation. This case report describes a young man who developed a unilateral abducens and bilateral facial nerve palsies following a posterior fossa exploration confined to an extradural compartment. There are different theories to explain this presentation, but the exact mechanism remains unclear. We propose that this patient cranial nerve palsies developed following cerebrospinal fluid (CSF) leak, potentially as a consequence of rapid change in CSF dynamics. PMID:26951144

  4. Development of conductive hearing loss due to posterior semicircular canal dehiscence.

    PubMed

    Kubota, Marie; Kubo, Kazuhiko; Yasui, Tetsuro; Matsumoto, Nozomu; Komune, Shizuo

    2015-06-01

    We herein report a case of posterior semicircular canal dehiscence (SCD) syndrome who had been audiologically followed up for eight years. The patient originally had sensorineural hearing loss. The audiogram had gradually transformed to pure conductive hearing loss. The posterior SCD was identified in CT scan. The reported case showed the possibility to distinguish the mechanism at play underlying the typical conductive hearing loss in SCD patients by tracing the transition of the hearing loss pattern. This information is of much help to predict the hearing outcomes if surgical intervention were chosen for the treatment.

  5. Patient function after a posterior stabilizing total knee arthroplasty: cam-post engagement and knee kinematics.

    PubMed

    Suggs, Jeremy F; Hanson, George R; Park, Sang Eun; Moynihan, Angela L; Li, Guoan

    2008-03-01

    Even though posterior substituting total knee arthroplasty has been widely used in surgery, how the cam-post mechanism (posterior substituting mechanism) affects knee joint kinematics and function in patients is not known. The objective of the present study was to investigate posterior femoral translation, internal tibial rotation, tibiofemoral contact, and cam-post engagement of total knee arthroplasty patients during in vivo weight-bearing flexion. Twenty-four knees with a PS TKA were investigated while performing a single leg weight-bearing lunge from full extension to maximum flexion as images were recorded using a dual fluoroscopic system. The in vivo knee position at each targeted flexion angle was reproduced using 3D TKA models and the fluoroscopic images. The kinematics of the knee was measured from the series of the total knee arthroplasty models. The cam-post engagement was determined when the surface model of the femoral cam overlapped with that of the tibial post. The mean maximum flexion angle for all the subjects was 112.5 +/- 13.1 degrees . The mean flexion angle where cam-post engagement was observed was 91.1 +/- 10.9 degrees . The femur moved anteriorly from 0 degrees to 30 degrees and posteriorly through the rest of the flexion range. The internal tibial rotation increased approximately 6 degrees from full extension to 90 degrees of flexion and decreased slightly with further flexion. Both the medial and lateral contact point moved posteriorly from 0 degrees to 30 degrees , remained relatively constant from 30 degrees to 90 degrees , and then moved further posterior from 90 degrees to maximum flexion. The in vivo cam-post engagement corresponded to increased posterior translation and reduced internal tibial rotation at high flexion of the posterior substituting total knee arthroplasty. The initial cam-post engagement was also mildly correlated with the maximum flexion angle of the knee (R = 0.51, p = 0.019). A later cam-post engagement might

  6. Posterior ventricular anchoring neochordal repair of degenerative mitral regurgitation efficiently remodels and repositions posterior leaflet prolapse†

    PubMed Central

    Woo, Y. Joseph; MacArthur, John W.

    2013-01-01

    OBJECTIVES Mitral valve repair techniques for degenerative disease typically entail leaflet resection or neochordal construction, which may require extensive resection, leaflet detachment/reattachment, reliance on diseased native chords or precise neochordal measuring. Occasionally, impaired leaflet mobility, reduced coaptation surface and systolic anterior motion (SAM) may result. We describe a novel technique for addressing posterior leaflet prolapse/flail, which both simplifies repair and addresses these issues. METHODS Fifty-four patients (age 62 ± 11 years) with degenerative MR underwent this new repair, 36 of whom minimally-invasively. A CV5 Gore-Tex suture was placed into the posterior left ventricular myocardium underneath the prolapsing segment as an anchor. This suture was then used to imbricate a portion of the prolapsed segment into the ventricle, creating a smooth, broad, non-prolapsed coapting surface on a leaflet with preserved mobility, additional neochordal support and posteriorly positioned enough to preclude SAM. RESULTS Repair was successful in all patients. The mean MR grade was reduced from +3.8 to +0.1 with 50 of 54 patients having zero MR and 4 of the 54 having trace or mild MR. All patients had proper antero-posterior location of the coaptation line of a mean length of 10.2 mm, and preserved posterior leaflet mobility. No patients had SAM or mitral stenosis. All patients were discharged and are currently doing well. CONCLUSION This new technique facilitated efficient single-suture repair of the prolapsed posterior leaflet mitral regurgitation without the need for resection or sliding annuloplasty. It precluded the need for precise neochordal measurement and preserved the leaflet coaptation surface. PMID:23449863

  7. Talar Osteochondroma Fracture Presenting as Posterior Ankle Impingement.

    PubMed

    Ercin, Ersin; Bilgili, Mustafa Gokhan; Gamsizkan, Mehmet; Avsar, Serdar

    2016-05-01

    Osteochondromas are the most common benign bone tumors. They are usually asymptomatic and found incidentally. When symptomatic, the symptoms are usually due to its location and size. Fracture of an osteochondroma presenting as posterior ankle impingement is a rare condition. We describe a 22-year-old man with solitary exostosis who presented with a posterior ankle mass and posterior ankle impingement with 2 years of follow-up. Surgical intervention was the treatment of choice in this patient, and histologic examination revealed a benign osteochondroma. Osteochondromas found in the posterior aspect of the talus can be complicated by fracture due to persistent motion of the ankle. Talar osteochondroma should be included in the differential diagnosis of posterior ankle impingement causes. Posterior talar osteochondromas, especially when a stalk is present, should be treated surgically before it is more complicated by a fracture and posterior ankle impingement.

  8. Preparative activities in posterior parietal cortex for self-paced movement in monkeys.

    PubMed

    Gemba, Hisae; Matsuura-Nakao, Kazuko; Matsuzaki, Ryuichi

    2004-02-26

    Cortical field potentials were recorded by electrodes implanted chronically on the surface and at a 2.0-3.0 mm depth in various cortices in monkeys performing self-paced finger, toe, mouth, hand or trunk movements. Surface-negative, depth-positive potentials (readiness potential) appeared in the posterior parietal cortex about 1.0 s before onset of every self-paced movement, as well as in the premotor, motor and somatosensory cortices. Somatotopical distribution was seen in the readiness potential in the posterior parietal cortex, although it was not so distinct as that in the motor or somatosensory cortex. This suggests that the posterior parietal cortex is involved in preparation for self-paced movement of any body part. This study contributes to the investigation of central nervous mechanisms of voluntary movements initiated by internal stimulus.

  9. Surgical management of posterior fossa metastases.

    PubMed

    Sunderland, Geraint J; Jenkinson, Michael D; Zakaria, Rasheed

    2016-12-01

    The diagnosis of brain metastases is associated with a poor prognosis reflecting uncontrolled primary disease that has spread to the relative sanctuary of the central nervous system. 20 % of brain metastases occur in the posterior fossa and are associated with significant morbidity. The risk of acute hydrocephalus and potential for sudden death means these metastases are often dealt with as emergency cases. This approach means a full pre-operative assessment and staging of underlying disease may be neglected and a proportion of patients undergo comparatively high risk surgery with little or no survival benefit. This study aimed to assess outcomes in patients to identify factors that may assist in case selection. We report a retrospective case series of 92 consecutive patients operated for posterior fossa metastases between 2007 and 2012. Routine demographic data was collected plus data on performance status, primary cancer site, details of surgery, adjuvant treatment and survival. The only independent positive prognostic factors identified on multivariate analysis were good performance status (if Karnofsky performance score >70, hazard ratio (HR) for death 0.36, 95 % confidence interval (CI) 0.18-0.69), adjuvant whole brain radiotherapy (HR 0.37, 95 % CI 0.21-0.65) and adjuvant chemotherapy where there was extracranial disease and non-synchronous presentation (HR 0.51, 95 % CI 0.31-0.82). Patients presenting with posterior fossa metastases may not be investigated as thoroughly as those with supratentorial tumours. Staging and assessment is essential however, and in the meantime emergencies related to tumour mass effect should be managed with steroids and cerebrospinal fluid diversion as required.

  10. Minimally invasive posterior cervical decompression using tubular retractor: The technical note and early clinical outcome

    PubMed Central

    Hur, Jung-Woo; Kim, Jin-Sung; Shin, Myeong-Hoon; Ryu, Kyeong-Sik

    2014-01-01

    Background: The aim of this work is to present a novel decompression technique that approaches cervical spine posteriorly, but through minimal invasive method using tubular retractor avoiding detachment of posterior musculature. Methods: Six patients underwent minimally invasive posterior cervical decompression using the tubular retractor system and surgical microscope. Minimally invasive access to the posterior cervical spine was performed with exposure through a paramedian muscle-splitting approach. With the assistance of a specialized tubular retraction system and deep soft tissue expansion mechanism, multilevel posterior cervical decompression could be accomplished. This approach also allows safe docking of the retractor system on the lateral mass, thus avoiding the cervical spinal canal during exposure. A standard operating microscope was used with ×10 magnification and 400 mm focal length. The hospital charts, magnetic resonance imaging studies, and follow-up records of all the patients were reviewed. Outcome was assessed by neurological status and visual analog scale (VAS) for neck and arm pain. Results: There was no significant complication related to operation. The follow-up time was 4-12 months (mean, 9 months). Muscle weakness improved in all patients; sensory deficits resolved in four patients and improved in two patients. Analysis of the mean VAS for radicular pain and VAS for neck pain showed significant improvement. Conclusions: The preliminary experiences with good clinical outcome seem to promise that this minimally invasive technique is a valid alternative option for the treatment of cervical spondylotic myelopathy. PMID:24778922

  11. Acute posterior fossa epidural hematoma in a newborn infant with Menkes disease.

    PubMed

    Takeuchi, Satoru; Horikawa, Masahiro; Wakamatsu, Hajime; Hashimoto, Jyunya; Nawashiro, Hiroshi

    2014-02-01

    Epidural hematoma (EDH) in newborn infants is rare compared with other types of intracranial hemorrhages. Furthermore, posterior fossa EDH is extremely rare. We present a case of posterior fossa EDH in an infant with Menkes disease with accessory bones in the occiput. A male infant with a condition diagnosed with Menkes disease by prenatal testing was born at 39 weeks via vacuum extraction. The patient presented with a mild tremor at 2 days after delivery. A brain computed tomography (CT) scan showed an acute EDH in the posterior fossa, extending into the occipitoparietal area. Three-dimensional CT and bone window CT scan revealed several accessory bones, diastasis of 1 accessory suture, a communicated fracture, and a linear fracture in the occipital bone. Furthermore, a bone fragment from a communicated fracture displaced toward the inside. The patient was treated conservatively for EDH because of his good general condition. The hematoma gradually resolved, and his tremor did not recur. We suggest the following mechanism of posterior fossa EDH development in our patient: (1) external force was applied to the occiput inside the birth canal during delivery, resulting in diastasis; (2) a communicated fracture occurred, and a bone fragment displaced toward the inside (linear fracture was caused indirectly by the force); (3) a transverse sinus was injured by the fragment; and (4) EDH developed in both the posterior fossa and supratentorial region. Copper deficiency can also cause fragility of connective tissues, vessels, and bones.

  12. [Posterior dislocation of the sternoclavicular joint].

    PubMed

    Mäkinen, Tatu; Madanat, Rami; Heinänen, Mikko; Brinck, Tuomas; Pajarinen, Jarkko

    2013-01-01

    Posterior dislocation of the sternoclavicular joint is a rare injury. It can be associated with life-threatening complications. Computed tomography is the imaging modality of choice with which possible associated injuries can be detected. Acute injuries are managed with closed reduction under general anaesthesia. A fracture-dislocation is inherently more unstable than an isolated dislocation. Surgical treatment is advocated in cases of delayed diagnosis or failed closed reduction. With early diagnosis and treatment, the long-term outcome of this injury is good.

  13. Decompression of Posterior Ankle Impingement With Concomitant Anterior Ankle Pathology by Posterior Ankle Arthroscopy in the Supine Position.

    PubMed

    Lui, Tun Hing

    2016-10-01

    Posterior ankle endoscopy is a safe and effective approach for treatment of posterior ankle impingement. This is usually performed with the patient in prone position. The purpose of this technical note is to describe an arthroscopic approach of decompression of posterior ankle impingement with the patient in supine position. This is indicated if there is posterior ankle impingement together with other ankle pathology requiring anterior ankle arthroscopy. This approach allows treatment of both anterior ankle and posterior ankle pathology with the patient in the supine position. Concomitant anterior ankle arthroscopy can be performed with the usual orientation without the need of change of patient's position.

  14. Acute Tetraplegia after Posterior Cervical Laminectomy for Chronic Myelopathy.

    PubMed

    Iorio, Justin A; Jakoi, Andre M; Wetzel, Franklin T

    2015-11-01

    Spinal cord injury (SCI) during revision surgery for persistent multilevel cervical myelopathy (MCM) after an initial anterior procedure is rare. However, the pathophysiology of MCM, even prior to surgery, is a risk-factor for neurological deterioration due to the development of a "sick cord", which reflects pathological changes in the spinal cord that lower the threshold for injury. We report a case of persistent MCM despite a three-level ACDF and corpectomy who developed an incomplete C6 tetraplegia during revision cervical laminectomy and posterior instrumentation. Intraoperative neuromonitoring signal-changes occurred in the absence of mechanical trauma. Postoperative MRI of the cervical spine demonstrated increased T2 hyperintensity and cord expansion at C3 and C4 compared to the pre-laminectomy MRI. The patient has not made improvements in her neurological status at 13 months postoperatively. The pathophysiology of MCM is discussed in addition to perioperative imaging, neuromonitoring, and use of steroids.

  15. [Posterior Reversible Encephalopathy Syndrome Associated with Cancer Therapy].

    PubMed

    Mitsuya, Koichi; Nakasu, Yoko; Hayashi, Nakamasa; Yasui, Hirofumi; Ikeda, Takashi; Kuji, Shiho; Onozawa, Yusuke; Endo, Masahiro

    2016-03-01

    Posterior reversible encephalopathy syndrome(PRES)is a subacute neurological syndrome typically manifesting with headache, cortical blindness, and seizures. This syndrome is associated with risk factors such as malignant hypertension, eclampsia, and renal failure. Numerous case reports depict its occurrence in cancer patients. The direct causal mechanisms of PRES in cancer patients have not yet been identified. Cytotoxic chemotherapy may cause direct endothelial damage, which would impact the blood brain barrier. Angiogenesis inhibitors also cause elevation in blood pressure;this is significant, because PRES onset may be solely related to hypertension. An increased number of case reports involving new molecular targeted agent suggests that incidence of PRES as an oncological emergency may increase in the future.

  16. Transient contribution of left posterior parietal cortex to cognitive restructuring

    PubMed Central

    Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

    2015-01-01

    Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring. PMID:25775998

  17. Functional analysis of centipede development supports roles for Wnt genes in posterior development and segment generation.

    PubMed

    Hayden, Luke; Schlosser, Gerhard; Arthur, Wallace

    2015-01-01

    The genes of the Wnt family play important and highly conserved roles in posterior growth and development in a wide range of animal taxa. Wnt genes also operate in arthropod segmentation, and there has been much recent debate regarding the relationship between arthropod and vertebrate segmentation mechanisms. Due to its phylogenetic position, body form, and possession of many (11) Wnt genes, the centipede Strigamia maritima is a useful system with which to examine these issues. This study takes a functional approach based on treatment with lithium chloride, which causes ubiquitous activation of canonical Wnt signalling. This is the first functional developmental study performed in any of the 15,000 species of the arthropod subphylum Myriapoda. The expression of all 11 Wnt genes in Strigamia was analyzed in relation to posterior development. Three of these genes, Wnt11, Wnt5, and WntA, were strongly expressed in the posterior region and, thus, may play important roles in posterior developmental processes. In support of this hypothesis, LiCl treatment of S. maritima embryos was observed to produce posterior developmental defects and perturbations in AbdB and Delta expression. The effects of LiCl differ depending on the developmental stage treated, with more severe effects elicited by treatment during germband formation than by treatment at later stages. These results support a role for Wnt signalling in conferring posterior identity in Strigamia. In addition, data from this study are consistent with the hypothesis of segmentation based on a "clock and wavefront" mechanism operating in this species.

  18. Presynaptic and extrasynaptic regulation of posterior nucleus of thalamus.

    PubMed

    Park, Anthony; Li, Ying; Masri, Radi; Keller, Asaf

    2017-03-22

    The posterior nucleus of thalamus (PO) is a higher-order nucleus involved in sensorimotor processing, including nociception. An important characteristic of PO is its wide range of activity profiles that vary across states of arousal, thought to underlie differences in somatosensory perception subject to attention and degree of consciousness. Further, PO loses the ability to down-regulate its activity level in some forms of chronic pain, suggesting that regulatory mechanisms underlying the normal modulation of PO activity may be pathologically altered. Yet, the mechanisms responsible for regulating such a wide dynamic range of activity are unknown. Here, we test a series of hypotheses regarding the function of several presynaptic receptors on both GABAergic and glutamatergic afferents targeting PO in mouse, using acute slice electrophysiology. We found that presynaptic GABAB receptors are present on both GABAergic and glutamatergic terminals in PO, but only those on GABAergic terminals are tonically active. We also found that release from GABAergic terminals, but not glutamatergic terminals, is suppressed by cholinergic activation, and that a subpopulation of GABAergic terminals is regulated by cannabinoids. Finally, we discovered the presence of tonic currents mediated by extrasynaptic GABAA receptors in PO that are heterogeneously distributed across the nucleus. Thus, we demonstrate that multiple regulatory mechanisms concurrently exist in PO, and we propose that regulation of inhibition, rather than excitation, is the more consequential mechanism by which PO activity can be regulated.

  19. Traumatic posterior dislocation of hip in children.

    PubMed

    Kutty, S; Thornes, B; Curtin, W A; Gilmore, M F

    2001-02-01

    Traumatic posterior dislocation of the hip joint in children is an uncommon injury. It constitutes a true orthopedic emergency. It makes up over 80% of pediatric hip dislocations. In children, it can occur as a result of minimal trauma, which is attributed to a soft pliable acetabulum and ligamentous laxity. In skeletally mature adolescents, a greater force is required to dislocate the hip joint. Delay in reduction is associated with long-term complications such as avascular necrosis and degenerative arthritis. Avascular necrosis is related to the duration of dislocation. A poorer prognosis is associated with delay in reduction beyond 6 hours, advanced skeletal maturity, or multiple traumas. Prompt reduction minimizes complications. We report two cases of traumatic posterior dislocation of hip in children aged 3 and 14 years. Both were reduced within 6 hours of dislocation, and review at 6 months revealed normal examination and no evidence of any post-traumatic changes. Post-reduction treatment remains without a consensus. This review highlights the clinical presentation, management, and time-sensitive complications of the injury.

  20. Management of an Uncomplicated Posterior Elbow Dislocation

    PubMed Central

    Blackard, Douglas; Sampson, Jo-Ann

    1997-01-01

    Objective: To present a case of an uncomplicated posterior elbow dislocation in a US World Cup athlete and discuss her rehabilitation. Background: Traditional protocol for management of this injury has been splint immobilization for several weeks, but research suggests a shortened duration of immobilization and early active motion. Differential Diagnosis: Elbow dislocation with possible fracture. Treatment: The dislocation was reduced and a compression bandage and sling were applied. The sports medicine staff and athlete determined that rehabilitation would involve limited immobilization with a posterior splint. Also, active range-of- motion exercises were to be incorporated early in the range-of- motion program to decrease pain at the articulation. Uniqueness: The athlete was not immobilized and her aggressive five-phase rehabilitation program progressed according to decrease in inflammation and increase in range of motion and strength. Conclusions: Shortened immobilization and return to World Championship competition 6 weeks postinjury had no longterm adverse effects on the athlete. ImagesFig 1.Fig 2.Fig 3.Fig 4.Fig. 5. PMID:16558436

  1. Posterior malleolar fractures of the ankle.

    PubMed

    Bartoníček, J; Rammelt, S; Tuček, M; Naňka, O

    2015-12-01

    Despite an increasing awareness of injuries to PM in ankle fracture-dislocations, there are still many open questions. The mere presence of a posterior fragment leads to significantly poorer outcomes. Adequate diagnosis, classification and treatment require preoperative CT examination, preferably with 3D reconstructions. The indication for surgical treatment is made individually on the basis of comprehensive assessment of the three-dimensional outline of the PM fracture and all associated injuries to the ankle including syndesmotic instability. Anatomic fixation of the avulsed posterior tibiofibular ligament will contribute to syndesmotic stability and restore the integrity of the incisura tibiae thus facilitating anatomic reduction of the distal fibula. A necessary prerequisite is mastering of posterolateral and posteromedial approaches and the technique of direct reduction and internal fixation. Further clinical studies with higher numbers of patients treated by similar methods and evaluation of pre- and postoperative CT scans will be necessary to determine reliable prognostic factors associated with certain types of PM fractures and associated injuries to the ankle.

  2. Microsurgical anatomy of the posterior fossa cisterns.

    PubMed

    Matsuno, H; Rhoton, A L; Peace, D

    1988-07-01

    The microsurgical anatomy of the posterior fossa cisterns was examined in 15 cadavers using 3X to 40X magnification. Liliequist's membrane was found to split into two arachnoidal sheets as it spreads upward from the dorsum sellae: an upper sheet, called the diencephalic membrane, which attaches to the diencephalon at the posterior edge of the mamillary bodies, and a lower sheet, called the mesencephalic membrane, which attaches along the junction of the midbrain and pons. Several other arachnoidal membranes that separate the cisterns were identified. These include the anterior pontine membrane, which separates the prepontine and cerebellopontine cisterns; the lateral pontomesencephalic membrane, which separates the ambient and cerebellopontine cisterns; the medial pontomedullary membrane, which separates the premedullary and prepontine cisterns; and the lateral pontomedullary membrane, which separates the cerebellopontine and cerebellomedullary cisterns. The three cisterns in which the arachnoid trabeculae and membranes are the most dense and present the greatest obstacle at operation are the interpeduncular and quadrigeminal cisterns and the cisterna magna. Numerous arachnoid membranes were found to intersect the oculomotor nerves. The neural and vascular structures in each cistern are reviewed.

  3. Prehension Movements in a Patient (AC) with Posterior Parietal Cortex Damage and Posterior Callosal Section

    ERIC Educational Resources Information Center

    Frak, Victor; Paulignan, Yves; Jeannerod, Marc; Michel, Francois; Cohen, Henri

    2006-01-01

    Prehension movements of the right hand were recorded in a right-handed man (AC), with an injury to the left posterior parietal cortex (PPC) and with a section of the left half of the splenium. The kinematic analysis of AC's grasping movements in direct and perturbed conditions was compared to that of five control subjects. A novel effect in…

  4. GNSS integer ambiguity validation based on posterior probability

    NASA Astrophysics Data System (ADS)

    Wu, Zemin; Bian, Shaofeng

    2015-10-01

    GNSS integer ambiguity validation is considered to be a challenge task for decades. Several kinds of validation tests are developed and widely used in these years, but theoretical basis is their weakness. Ambiguity validation theoretically is an issue of hypothesis test. In the frame of Bayesian hypothesis testing, posterior probability is the canonical standard that statistical decision should be based on. In this contribution, (i) we derive the posterior probability of the fixed ambiguity based on the Bayesian principle and modify it for practice ambiguity validation. (ii) The optimal property of the posterior probability test is proved based on an extended Neyman-Pearson lemma. Since validation failure rate is the issue users most concerned about, (iii) we derive the failure rate upper bound of the posterior probability test, so the user can use the posterior probability test either in the fixed posterior probability or in the fixed failure rate way. Simulated as well as real observed data are used for experimental validations. The results show that (i) the posterior probability test is the most effective within the R-ratio test, difference test, ellipsoidal integer aperture test and posterior probability test, (ii) the posterior probability test is computational efficient and (iii) the failure rate estimation for posterior probability test is useful.

  5. Visual input to the mouse lateral posterior and posterior thalamic nuclei: photoreceptive origins and retinotopic order

    PubMed Central

    Allen, Annette E.; Procyk, Christopher A.; Howarth, Michael; Walmsley, Lauren

    2016-01-01

    Key points The lateral posterior and posterior thalamic nuclei have been implicated in aspects of visually guided behaviour and reflex responses to light, including those dependent on melanopsin photoreception.Here we investigated the extent and basic properties of visually evoked activity across the mouse lateral posterior and posterior thalamus.We show that a subset of retinal projections to these regions derive from melanopsin‐expressing retinal ganglion cells and find many cells that exhibit melanopsin‐dependent changes in firing.We also show that subsets of cells across these regions integrate signals from both eyes in various ways and that, within the lateral posterior thalamus, visual responses are retinotopically ordered. Abstract In addition to the primary thalamocortical visual relay in the lateral geniculate nuclei, a number of other thalamic regions contribute to aspects of visual processing. Thus, the lateral posterior thalamic nuclei (LP/pulvinar) appear important for various functions including determining visual saliency, visually guided behaviours and, alongside dorsal portions of the posterior thalamic nuclei (Po), multisensory processing of information related to aversive stimuli. However, despite the growing importance of mice as a model for understanding visual system organisation, at present we know very little about the basic visual response properties of cells in the mouse LP or Po. Prompted by earlier suggestions that melanopsin photoreception might be important for certain functions of these nuclei, we first employ specific viral tracing to show that a subset of retinal projections to the LP derive from melanopsin‐expressing retinal ganglion cells. We next use multielectrode electrophysiology to demonstrate that LP and dorsal Po cells exhibit a variety of responses to simple visual stimuli including two distinct classes that express melanopsin‐dependent changes in firing (together comprising ∼25% of neurons we recorded). We also

  6. Application of Adipose-Derived Stem Cells on Scleral Contact Lens Carrier in an Animal Model of Severe Acute Alkaline Burn

    PubMed Central

    Espandar, Ladan; Caldwell, Delmar; Watson, Richard; Blanco-Mezquita, Tomas; Zhang, Shijia; Bunnell, Bruce

    2015-01-01

    Purpose To evaluate the therapeutic effect of human adipose-derived stem cells (hASCs) overlaid on a scleral contact lens (SCL) carrier in a rabbit model of ocular alkaline burn. Materials and Methods After inducing alkaline burn in 11 New Zealand white rabbits, hASCs cultured on SCLs were placed on the right eye of 5 rabbits, SCLs without cells were used in 5, and no treatment was applied in 1 eye. Each eye was examined and photographed for corneal vascularization, opacities, and epithelial defect in week 1, 2, and 4 after surgery. After 1 month, rabbits were killed and the corneas were removed and cut in half for electron and light microscopy examination. Results Human adipose-derived stem cells were attached to SCL surface and confluent easily. Human adipose-derived stem cells on SCL eyes showed smaller epithelial defect, less corneal opacity, corneal neovascularization relative to SCL eyes. Both groups showed no symblepharon. However, the cornea in the untreated eye was melted in 2 weeks and developed severe symblepharon. Conclusion Human adipose-derived stem cells on SCL can reduce inflammation and corneal haziness in severe ocular alkaline burn injury in rabbits. PMID:24901976

  7. Scleral buckling for primary rhegmatogenous retinal detachment using noncontact wide-angle viewing system with a cannula-based 25 G chandelier endoilluminator

    PubMed Central

    Imai, Hisanori; Tagami, Mizuki; Azumi, Atsushi

    2015-01-01

    Purpose The aim of this study is to report the result of scleral buckling (SB) using a combination of a noncontact wide-angle viewing system and a cannula-based 25 G chandelier endoilluminator. Methods Retrospective analyses of the medical records of 79 eyes of 79 patients with primary uncomplicated rhegmatogenous retinal detachments who had underwent SB using a combination of a noncontact wide-angle viewing system and a chandelier endoilluminator were performed. Results There were 50 men and 29 women. The mean ± standard deviation age was 43.7±16.0 years. Their preoperative best-corrected visual acuity (BCVA) was 0.31±0.65 logMAR units. The final BCVA was 0.10±0.31 logMAR units, which was significantly better than the preoperative BCVA (P<0.01). The initial and final anatomical success rates were 92.4% and 100%, respectively. Backward logistic multiple regression analysis revealed no relationship between explanatory variables and the primary anatomic success (P=0.104). Conclusion SB using a combination of a noncontact wide-angle viewing system and a chandelier endoilluminator is a modified new technique and may be a valid option for the management of rhegmatogenous retinal detachments. PMID:26635466

  8. A comparative study of the circle of Willis in fetal and adult life. The configuration of the posterior bifurcation of the posterior communicating artery.

    PubMed Central

    Van Overbeeke, J J; Hillen, B; Tulleken, C A

    1991-01-01

    The configuration of the posterior bifurcation of the posterior communicating artery is commonly described as the 'adult configuration' if the diameter of the precommunicating part of the posterior cerebral artery (P1) is larger than the diameter of the posterior communicating artery itself (PCA). In these cases the blood supply to the occipital lobes is mainly from the vertebro-basilar system. Only in a minority of cases is the fetal or embryonic configuration found. Here the diameter of the PCA is larger than the diameter of the P1 and the blood supply to the occipital lobes is mainly from the internal carotid artery via the posterior communicating artery. In order to track the origin of these different configurations, 53 complete circles of Willis (106 sides) in brains of fetuses and infants aged from 12 weeks to 60 weeks after conception were examined with the aid of an operating microscope, and measurements were made of the diameters of the PCA, P1 and P2. It is concluded that the variations of this part of the circle of Willis are the result of developmental modifications. This is confirmed by a statistical analysis that shows a relation between the stage of development of the brain and the occurrence of the different configurations. The frequencies of the adult and fetal configurations gradually increase at the expense of the transitional configurations. This configuration is found early in development and is characterised by the equality of the diameters of the PCA and P1. These findings contradict the views, found in the literature, that the variations either exist early in development as a consequence of genetic factors or arise after birth as a consequence of mechanical genetic factors. Images Fig. 1 Fig. 2 PMID:1917674

  9. Interplay between a Wnt-dependent organiser and the Notch segmentation clock regulates posterior development in Periplaneta americana

    PubMed Central

    Chesebro, John E.; Pueyo, Jose Ignacio; Couso, Juan Pablo

    2013-01-01

    Summary Sequential addition of segments in the posteriorly growing end of the embryo is a developmental mechanism common to many bilaterians. However, posterior growth and patterning in most animals also entails the establishment of a ‘posterior organiser’ that expresses the Caudal and Wnt proteins and has been proposed to be an ancestral feature of animal development. We have studied the functional relationships between the Wnt-driven organiser and the segmentation mechanisms in a basal insect, the cockroach Periplaneta americana. Here, posteriorly-expressed Wnt1 promotes caudal and Delta expression early in development to generate a growth zone from which segments will later bud off. caudal maintains the undifferentiated growth zone by dampening Delta expression, and hence Notch-mediated segmentation occurs just outside the caudal domain. In turn, Delta expression maintains Wnt1, maintaining this posterior gene network until all segments have formed. This feedback between caudal, Wnt and Notch-signalling in regulating growth and segmentation seems conserved in other arthropods, with some aspects found even in vertebrates. Thus our findings not only support an ancestral Wnt posterior organiser, but also impinge on the proposals for a common origin of segmentation in arthropods, annelids and vertebrates. PMID:23430316

  10. Incidence of Recurrence in Posterior Circulation Childhood Arterial Ischemic Stroke

    PubMed Central

    Uohara, Michael Y.; Beslow, Lauren A.; Billinghurst, Lori; Jones, Brianna M.; Kessler, Sudha K.; Licht, Daniel J.; Ichord, Rebecca N.

    2017-01-01

    IMPORTANCE Childhood arterial ischemic stroke (CAIS) affects approximately 1.6 per 100 000 children per year, while stroke recurs in up to 20%of patients at 5 years. Factors determining the risk of recurrence are incompletely understood. OBJECTIVE To investigate the incidence of the recurrence of CAIS in the posterior and anterior circulations to determine if the risk differs between the 2 locations. DESIGN, SETTING, AND PARTICIPANTS A retrospective analysis of CAIS was conducted among children enrolled in a single-center prospective consecutive cohort at The Children’s Hospital of Philadelphia between January 1, 2006, and January 1, 2015. Children with confirmed CAIS occurring between 29 days and 17.99 years were evaluated for inclusion. Patients were excluded if infarcts were located in both the anterior and posterior distributions or if CAIS occurred as a complication of intracranial surgery or brain tumor. MAIN OUTCOMES AND MEASURES Stroke recurrence. RESULTS The study population included 107 patients (75 boys [70.1%] and 32 girls [29.9%]; median age at AIS, 7.7 years [interquartile range, 3.1–13.6 years]). Sixty-one children had anterior circulation CAIS (ACAIS) and 46 had posterior circulation CAIS (PCAIS). Median follow-up was 20.9 months (interquartile range, 8.7–40.4 months). For ACAIS, recurrence-free survival was 100% at 1 month and 96%(95%CI, 85%–99%) at 1 and 3 years. For PCAIS, recurrence-free survival was 88%(95%CI, 75%–95%) at 1 month and 81%(95% CI, 66%–90%) at 1 and 3 years. The hazard ratio for recurrence after PCAIS compared with ACAIS was 6.4 (95%CI, 1.4–29.8; P = .02) in univariable analysis and 5.3 (95%CI, 1.1–26.4; P = .04) after adjusting for sex and cervical dissection. CONCLUSIONS AND RELEVANCE We identified a subgroup of patients that comprise more than 80% of recurrences of CAIS. Three years after incident stroke, 19% of children with PCAIS had a recurrence compared with 4%of patients with ACAIS. Different mechanisms of

  11. Iodine-125 radiation of posterior uveal melanoma

    SciTech Connect

    Packer, S.

    1987-12-01

    Twenty-eight cases of posterior choroidal melanoma were treated with iodine-125 in gold eye plaques. Eleven cases were located within 3.0 mm of the optic nerve (group A), nine were within 3.0 mm of the fovea (group B), and eight were within 3.0 mm of the optic nerve and fovea (group C). The mean follow-up of group A was 46.3 months; group B, 25.5 months; and group C, 42.7 months. Complications included macular edema, cataract and tumor growth. Visual acuity remained within two lines of that tested preoperatively for 4 of 11 patients in group A, 4 of 9 in group B, and 5 of 8 in group C. These results with iodine-125 suggest it as an appropriate treatment for patients with choroidal melanoma located near optic nerve and/or macula.

  12. Polycythemia causing posterior segment vascular occlusions

    PubMed Central

    Ganesan, Suganeswari; Raman, Rajiv; Sharma, Tarun

    2017-01-01

    A 44-year-old male patient presented with features suggestive of transient central retinal artery occlusion (CRAO) followed by permanent CRAO and lateral posterior ciliary artery occlusion. He had diagnostic features of polycythemia vera (PV). When presented for the first time, the patient had features of ocular ischemia such as ocular pain, conjunctival congestion, and retinal opacification but with normal arm-to-retina time and normal arteriovenous transit time. During the second presentation, he had ocular pain, congested conjunctiva, retinal opacification, cherry red spot with box-carrying of retinal vessels, and choroidal infarct (Amalric's sign). He had lost light perception in that eye. Patients with polycythemia are prone to multifocal vascular occlusions and this can be the presenting feature in PV. A timely diagnosis and prompt management can prevent these repeated thromboembolic occlusive episodes. PMID:28298862

  13. Hemifacial spasm and posterior auricular muscle.

    PubMed

    Kiziltan, M; Sahin, R; Uzun, N; Kiziltan, G

    2006-09-01

    We aimed to investigate to which extent posterior auricular muscle (PAM) was affected and whether it contributed to the reflex activity in hemifacial spasm (HFS) patients. 19 HFS patients' spasm activities were recorded from facial muscles. Spasm activity of PAM was recorded synchronously on the symptomatic side in all patients. Lateral spread of blink reflex to orbicularis oris and PAMs were recorded in all but two patients. Botulinum toxin was applied to the PAM with the 14 patients presenting tinnitus, "clicking" or a "ticking" sound on the sane side and other positive auricular symptoms. After treatment, there was symptomatic improvement in 9 of 14 patients. The patients presenting with auricular symptoms and showing spasm activity in their PAMs can be thought as a candidate for botulinum toxin treatment scheme.

  14. Supine to prolonged lateral position: a novel therapeutic maneuver for posterior canal benign paroxysmal positional vertigo.

    PubMed

    Shih, Cheng-Ping; Wang, Chih-Hung

    2013-05-01

    The treatment of posterior canal benign paroxysmal positional vertigo often involves repositioning maneuvers and exercises; however, these procedures may not be suitable for patients with limb disabilities or back disorders, or for elder patients. We sought to develop a simple therapeutic maneuver as an alternative procedure, suitable for patients with a wide range of physical ability. A simple therapeutic maneuver, supine to prolonged lateral position, was developed based on the mechanism of canalolithiasis. Its efficacy in treating posterior canal benign paroxysmal positional vertigo was evaluated in a prospective study consisting of 81 objective and 13 subjective posterior canal benign paroxysmal positional vertigo patients. A successful outcome was defined as a negative Dix-Hallpike test within 2 weeks followed by the continued absence of symptoms of vertigo or dizziness for the next 4 weeks. Seventy-two patients with objective posterior canal benign paroxysmal positional vertigo and all 13 patients with subjective posterior canal benign paroxysmal positional vertigo were successfully treated: resolution rates were 88.9 and 100 %, respectively. In the objective group, negative Dix-Hallpike tests were obtained at 1 and 2 weeks in 66.7 and 88.9 % of patients, respectively. In the subjective group, the percentages of patients free of side-dependent vertigo illusions at 1 and 2 weeks were 84.6 and 100 %, respectively. These results suggest that the supine to prolonged lateral position maneuver, which is easy to perform and generally well tolerated, could be recommended as an alternative treatment modality for patients with posterior canal benign paroxysmal positional vertigo.

  15. The role of the posterior fusiform gyrus in reading.

    PubMed

    Devlin, Joseph T; Jamison, Helen L; Gonnerman, Laura M; Matthews, Paul M

    2006-06-01

    Studies of skilled reading [Price, C. J., & Mechelli, A. Reading and reading disturbance. Current Opinion in Neurobiology, 15, 231-238, 2005], its acquisition in children [Shaywitz, B. A., Shaywitz, S. E., Pugh, K. R., Mencl, W. E., Fulbright, R. K., Skudlarski, P., et al. Disruption of posterior brain systems for reading in children with developmental dyslexia. Biological Psychiatry, 52, 101-110, 2002; Turkeltaub, P. E., Gareau, L., Flowers, D. L., Zeffiro, T. A., & Eden, G. F. Development of neural mechanisms for reading. Nature Neuroscience, 6, 767-773, 2003], and its impairment in patients with pure alexia [Leff, A. P., Crewes, H., Plant, G. T., Scott, S. K., Kennard, C., & Wise, R. J. The functional anatomy of single word reading in patients with hemianopic and pure alexia. Brain, 124, 510-521, 2001] all highlight the importance of the left posterior fusiform cortex in visual word recognition. We used visual masked priming and functional magnetic resonance imaging to elucidate the specific functional contribution of this region to reading and found that (1) unlike words, repetition of pseudowords ("solst-solst") did not produce a neural priming effect in this region, (2) orthographically related words such as "corner-corn" did produce a neural priming effect, but (3) this orthographic priming effect was reduced when prime-target pairs were semantically related ("teacher-teach"). These findings conflict with the notion of stored visual word forms and instead suggest that this region acts as an interface between visual form information and higher order stimulus properties such as its associated sound and meaning. More importantly, this function is not specific to reading but is also engaged when processing any meaningful visual stimulus.

  16. Diagnostics for insufficiencies of posterior calculations in Bayesian signal inference.

    PubMed

    Dorn, Sebastian; Oppermann, Niels; Ensslin, Torsten A

    2013-11-01

    We present an error-diagnostic validation method for posterior distributions in Bayesian signal inference, an advancement of a previous work. It transfers deviations from the correct posterior into characteristic deviations from a uniform distribution of a quantity constructed for this purpose. We show that this method is able to reveal and discriminate several kinds of numerical and approximation errors, as well as their impact on the posterior distribution. For this we present four typical analytical examples of posteriors with incorrect variance, skewness, position of the maximum, or normalization. We show further how this test can be applied to multidimensional signals.

  17. Posterior tibial subluxation and short-term arthritis resulting from failed posterior cruciate ligament reconstruction.

    PubMed

    Mavrodontidis, Alexandros N; Papadonikolakis, Anastasios; Moebius, Ulf G; Gelalis, Ioannis; Motsis, Efstathios; Soucacos, Panayotis N

    2003-01-01

    Posterior tibial subluxations because of combined or isolated posterior cruciate ligament (PCL) injuries require detailed evaluation. PCL reconstructions are difficult procedures because of the low rate of such injuries and the complex anatomy of the ligament. We report on 2 cases of failed PCL reconstruction because of malpositioned femoral tunnels. These 2 cases support the existing biomechanical evidence that the correct placement of the tunnels, especially in the femur, is a major factor in defining the outcome. It seems that the drilling of the tunnels, especially in the femur, during PCL reconstruction must be performed with accuracy and always be evaluated in cases of graft failure. In addition, failed PCL reconstructions are usually accompanied by a short-term excessive arthritis that results in poor functional outcome.

  18. Posterior tail development in the salamander Eurycea cirrigera: exploring cellular dynamics across life stages.

    PubMed

    Vaglia, Janet L; Fornari, Chet; Evans, Paula K

    2017-03-01

    During embryogenesis, the body axis elongates and specializes. In vertebrate groups such as salamanders and lizards, elongation of the posterior body axis (tail) continues throughout life. This phenomenon of post-embryonic tail elongation via addition of vertebrae has remained largely unexplored, and little is known about the underlying developmental mechanisms that promote vertebral addition. Our research investigated tail elongation across life stages in a non-model salamander species, Eurycea cirrigera (Plethodontidae). Post-embryonic addition of segments suggests that the tail tip retains some aspects of embryonic cell/tissue organization and gene expression throughout the life cycle. We describe cell and tissue differentiation and segmentation of the posterior tail using serial histology and expression of the axial tissue markers, MF-20 and Pax6. Embryonic expression patterns of HoxA13 and C13 are shown with in situ hybridization. Tissue sections reveal that the posterior spinal cord forms via cavitation and precedes development of the underlying cartilaginous rod after embryogenesis. Post-embryonic tail elongation occurs in the absence of somites and mesenchymal cells lateral to the midline express MF-20. Pax6 expression was observed only in the spinal cord and some mesenchymal cells of adult Eurycea tails. Distinct temporal and spatial patterns of posterior Hox13 gene expression were observed throughout embryogenesis. Overall, important insights to cell organization, differentiation, and posterior Hox gene expression may be gained from this work. We suggest that further work on gene expression in the elongating adult tail could shed light on mechanisms that link continual axial elongation with regeneration.

  19. Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

    PubMed Central

    Young, Ki Won; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-01-01

    Background We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Methods Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. Results The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Conclusions Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were

  20. Radial head fracture associated with posterior interosseous nerve injury.

    PubMed

    Terra, Bernardo Barcellos; Sassine, Tannus Jorge; Lima, Guilherme de Freitas; Rodrigues, Leandro Marano; Padua, David Victoria Hoffmann; Nadai, Anderson de

    2016-01-01

    Fractures of the radial head and radial neck correspond to 1.7-5.4% of all fractures and approximately 30% may present associated injuries. In the literature, there are few reports of radial head fracture with posterior interosseous nerve injury. This study aimed to report a case of radial head fracture associated with posterior interosseous nerve injury.

  1. Trabeculectomy combined with deep sclerectomy and scleral flap suture tension adjustment under an anterior chamber maintainer: a new modification of trabeculectomy.

    PubMed

    Kayikcioglu, Ozcan R; Emre, Sinan; Kaya, Ziya

    2010-06-01

    The objective of this study was to investigate the efficacy and safety of trabeculectomy combined with deep sclerectomy in patients with primary open angled glaucoma (POAG) and to compare the results with those from conventional trabeculectomy. In the study 12 eyes of 10 patients operated with trabeculectomy combined with deep sclerectomy (Group I) and 16 eyes of 16 patients operated with conventional trabeculectomy surgery (Group II) were included. In the described form of combined deep sclerectomy with the trabeculectomy technique the superficial scleral flap was sutured with 10/0 monofilament, the number and tension of sutures were adjusted according to the outflow dynamics, under the scleral flap, of balanced salt solution (BSS) provided by an anterior chamber maintainer. In groups I and II all the patients were male POAG cases with mean ages of 60.0 +/- 19.4 and 67.0 +/- 7.1 years, respectively. The mean follow-up periods were 8.3 +/- 3.5 months for group I and 16.6 +/- 7.0 months for group II. Preoperative mean IOP were 29.7 +/- 8.3 and 29.1 +/- 12.8 mmHg mmHg, and average topical antiglaucomatous medications were 2.9 +/- 0.7 and 2.7 +/- 1.1 for groups I and II, respectively. Postoperatively mean IOP measurements were reduced in groups I and II to 10.5 +/- 2.9 vs. 9.6 +/- 4.8 mmHg at 1 week, 13.7 +/- 5.6 vs. 16.0 +/- 9.8 at 1st month, 12.3 +/- 6.4 vs. 17.3 +/- 8.0 at 3rd month, 11.0 +/- 4.1 vs. 15.3 +/- 5.8 at 6th month, 10.8 +/- 1.6 vs. 16.1 +/- 4.4 at 12th month, and 11.0 +/- 1.0 vs. 16.7 +/- 5.0 at 18th month. Statistical analysis revealed that mean postoperative IOP measurements for group I were significantly lower than for group II for all measurements except the first week (P < 0.05). At 12th month, the complete (IOP <22 mmHg without medication) and qualified (IOP <22 mmHg with medication) success rates were 83.3 and 100% for group I and 63.6 and 90.9% for group II. Postoperatively at 12th month, the mean number of antiglaucoma medications had fallen to

  2. A shift in anterior–posterior positional information underlies the fin-to-limb evolution

    PubMed Central

    Onimaru, Koh; Kuraku, Shigehiro; Takagi, Wataru; Hyodo, Susumu; Sharpe, James; Tanaka, Mikiko

    2015-01-01

    The pectoral fins of ancestral fishes had multiple proximal elements connected to their pectoral girdles. During the fin-to-limb transition, anterior proximal elements were lost and only the most posterior one remained as the humerus. Thus, we hypothesised that an evolutionary alteration occurred in the anterior–posterior (AP) patterning system of limb buds. In this study, we examined the pectoral fin development of catshark (Scyliorhinus canicula) and revealed that the AP positional values in fin buds are shifted more posteriorly than mouse limb buds. Furthermore, examination of Gli3 function and regulation shows that catshark fins lack a specific AP patterning mechanism, which restricts its expression to an anterior domain in tetrapods. Finally, experimental perturbation of AP patterning in catshark fin buds results in an expansion of posterior values and loss of anterior skeletal elements. Together, these results suggest that a key genetic event of the fin-to-limb transformation was alteration of the AP patterning network. DOI: http://dx.doi.org/10.7554/eLife.07048.001 PMID:26283004

  3. Posterior parietal cortex as part of a neural network for directed attention in rats.

    PubMed

    Reep, Roger L; Corwin, James V

    2009-02-01

    A rodent model of directed attention has been developed based upon behavioral analysis of contralateral neglect, pharmacological manipulations, and anatomical analysis of neural circuitry. In each of these three domains the rodent model exhibits striking similarities to humans. We hypothesize that there is a specific thalamo-cortical-basal ganglia network that subserves spatial attentional functions. Key components of this network are medial agranular and posterior parietal cortex, dorsocentral striatum, and the lateral posterior thalamic nucleus. Several issues need to be addressed before we can hope to realistically understand or model the functions of this network. Among these are the roles of medial versus lateral posterior parietal cortex; cholinergic mechanisms in attention; interhemispheric interactions; the role of synchronous firing at the cortical, striatal, and thalamic levels; interactions between cortical and thalamic projections to the striatum; interactions between cortical and nigral inputs to the thalamus; the role of collicular inputs to the lateral posterior thalamic nucleus; the role of cerebral cortex versus superior colliculus in driving the motor output expressed as orienting behavior during directed attention; the extent to which the circuitry we describe for directed attention also plays a role in other forms of attention.

  4. Spectral-domain optical coherence tomography analysis of persistent subretinal fluid after scleral buckling surgery for macula-off retinal detachment

    PubMed Central

    Gharbiya, M; Malagola, R; Mariotti, C; Parisi, F; De Vico, U; Ganino, C; Grandinetti, F

    2015-01-01

    Purpose To determine the predictive value of markers for persistent subretinal fluid (SRF) absorption and the influence of subfoveal fluid on visual outcome after scleral buckle (SB) surgery for rhegmatogenous retinal detachment (RRD). Patients and methods This was a retrospective, observational study. We reviewed the medical records of 64 eyes of 64 patients who underwent SB surgery for macula-off RRD. Patients underwent clinical examination and spectral-domain optical coherence tomography before surgery, at 1 month and every 3 months postoperatively. The height and width of SRF bleb(s) were measured over time. Results Persistent SRF at 1 month was observed in 40 eyes (62.5%). SRF blebs were first detected 1.7±2.2 months postoperatively. In 29 cases that could be fully followed up, SRF blebs were completely absorbed 7.8±4.4 months postoperatively. Resolution of fluid was associated with an improvement of VA (P=0.003). Serial measurements of SRF bleb size showed that bleb width decreased significantly at all time points during the 12-month follow-up period (P<0.05), while significant bleb height decrease occurred from postoperative sixth month only (P<0.05). There was no correlation between VA outcomes and subfoveal bleb height or width (P>0.05). The cut-off value of the bleb width-to-height ratio level for predicting bleb absorption at 6 months was 7, with 89% sensitivity and 83% specificity. Conclusions Visual improvement may occur with late resolution of residual subfoveal fluid. A bleb width-to-height ratio >7 indicates a higher risk of SRF to persist beyond 6 months after surgery. PMID:26139048

  5. Wnt signaling and the evolution of embryonic posterior development.

    PubMed

    Martin, Benjamin L; Kimelman, David

    2009-03-10

    During vertebrate embryogenesis, most of the mesodermal tissue posterior to the head forms from a progenitor population that continuously adds blocks of muscles (the somites) from the back end of the embryo. Recent work in less commonly studied arthropods--the flour beetle Tribolium and the common house spider--provides evidence suggesting that this posterior growth process might be evolutionarily conserved, with canonical Wnt signaling playing a key role in vertebrates and invertebrates. We discuss these findings as well as other evidence that suggests that the genetic network controlling posterior growth was already present in the last common ancestor of the Bilateria. We also highlight other interesting commonalities as well as differences between posterior growth in vertebrates and invertebrates, suggest future areas of research, and hypothesize that posterior growth may facilitate evolution of animal body plans.

  6. Management of the posterior capsule during pediatric intraocular lens implantation.

    PubMed

    Buckley, E G; Klombers, L A; Seaber, J H; Scalise-Gordy, A; Minzter, R

    1993-06-15

    One of the major obstacles in pediatric intraocular lens implantation has been the subsequent dense opacification of the posterior capsule. We used a modification of the standard pediatric cataract surgical procedure, which involved endocapsular cataract extraction, posterior chamber intraocular lens implantation, pars plana posterior capsulotomy, and pars plana anterior vitrectomy in 20 consecutive patients with unilateral traumatic, radiation-induced, and developmental cataracts. Visual axes were rapidly restored in all patients without further intervention for posterior capsule opacification. Visual acuity returned to 20/40 or better in all patients and 75% of all patients (15 patients) reached maximum improvement by five weeks. No complications attributed to intraoperative removal of the posterior capsule occurred.

  7. New infectious etiologies for posterior uveitis.

    PubMed

    Khairallah, Moncef; Kahloun, Rim; Ben Yahia, Salim; Jelliti, Bechir; Messaoud, Riadh

    2013-01-01

    Emergent and resurgent arthropod vector-borne diseases are major causes of systemic morbidity and death and expanding worldwide. Among them, viral and bacterial agents including West Nile virus, Dengue fever, Chikungunya, Rift Valley fever, and rickettsioses have been recently associated with an array of ocular manifestations. These include anterior uveitis, retinitis, chorioretinitis, retinal vasculitis and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by the detection of a specific antibody in serum. Ocular involvement associated with emergent infections usually has a self-limited course, but it can result in persistent visual impairment. There is currently no proven specific treatment for arboviral diseases, and therapy is mostly supportive. Vaccination for humans against these viruses is still in the research phase. Doxycycline is the treatment of choice for rickettsial diseases. Prevention, including public measures to reduce the number of mosquitoes and personal protection, remains the mainstay for arthropod vector disease control. Influenza A (H1N1) virus was responsible for a pandemic human influenza in 2009, and was recently associated with various posterior segment changes.

  8. Facilitating text reading in posterior cortical atrophy

    PubMed Central

    Rajdev, Kishan; Shakespeare, Timothy J.; Leff, Alexander P.; Crutch, Sebastian J.

    2015-01-01

    Objective: We report (1) the quantitative investigation of text reading in posterior cortical atrophy (PCA), and (2) the effects of 2 novel software-based reading aids that result in dramatic improvements in the reading ability of patients with PCA. Methods: Reading performance, eye movements, and fixations were assessed in patients with PCA and typical Alzheimer disease and in healthy controls (experiment 1). Two reading aids (single- and double-word) were evaluated based on the notion that reducing the spatial and oculomotor demands of text reading might support reading in PCA (experiment 2). Results: Mean reading accuracy in patients with PCA was significantly worse (57%) compared with both patients with typical Alzheimer disease (98%) and healthy controls (99%); spatial aspects of passages were the primary determinants of text reading ability in PCA. Both aids led to considerable gains in reading accuracy (PCA mean reading accuracy: single-word reading aid = 96%; individual patient improvement range: 6%–270%) and self-rated measures of reading. Data suggest a greater efficiency of fixations and eye movements under the single-word reading aid in patients with PCA. Conclusions: These findings demonstrate how neurologic characterization of a neurodegenerative syndrome (PCA) and detailed cognitive analysis of an important everyday skill (reading) can combine to yield aids capable of supporting important everyday functional abilities. Classification of evidence: This study provides Class III evidence that for patients with PCA, 2 software-based reading aids (single-word and double-word) improve reading accuracy. PMID:26138948

  9. Automatic quantification of posterior capsule opacification

    NASA Astrophysics Data System (ADS)

    Barman, Sarah A.; Uyyanonvara, Bunyarit; Boyce, James F.; Sanguinetti, Giorgia; Hollick, Emma J.; Meacock, William R.; Spalton, David J.; Paplinski, Andrew P.

    2000-06-01

    After Cataract surgery where a plastic implant lens is implanted into the eye to replace the natural lens, many patients suffer from cell growth across a membrane situated at the back of the lens which degrades their vision. The cell growth is known as Posterior Capsule Opacification (or PCO). It is important to be able to quantify PCO so that the effect of different implant lens types and surgical techniques may be evaluated. Initial results obtained using a neural network to detect PCO from implant lenses are compared to an established but less automated method of detection, which segments the images using texture segmentation in conjunction with co- occurrence matrices. Tests show that the established method performs well in clinical validation and repeatability trials. The requirement to use a neural network to analyze the implant lens images evolved from the analysis of over 1000 images using the established co-occurrence matrix segmentation method. The work shows that a method based on neural networks is a promising tool to automate the procedure of calculating PCO.

  10. Representation of numerosity in posterior parietal cortex

    PubMed Central

    Roitman, Jamie D.; Brannon, Elizabeth M.; Platt, Michael L.

    2012-01-01

    Humans and animals appear to share a similar representation of number as an analog magnitude on an internal, subjective scale. Neurological and neurophysiological data suggest that posterior parietal cortex (PPC) is a critical component of the circuits that form the basis of numerical abilities in humans. Patients with parietal lesions are impaired in their ability to access the deep meaning of numbers. Acalculiac patients with inferior parietal damage often have difficulty performing arithmetic (2 + 4?) or number bisection (what is between 3 and 5?) tasks, but are able to recite multiplication tables and read or write numerals. Functional imaging studies of neurologically intact humans performing subtraction, number comparison, and non-verbal magnitude comparison tasks show activity in areas within the intraparietal sulcus (IPS). Taken together, clinical cases and imaging studies support a critical role for parietal cortex in the mental manipulation of numerical quantities. Further, responses of single PPC neurons in non-human primates are sensitive to the numerosity of visual stimuli independent of low-level stimulus qualities. When monkeys are trained to make explicit judgments about the numerical value of such stimuli, PPC neurons encode their cardinal numerical value; without such training PPC neurons appear to encode numerical magnitude in an analog fashion. Here we suggest that the spatial and integrative properties of PPC neurons contribute to their critical role in numerical cognition. PMID:22666194

  11. [Posterior reversible encephalopathy: beyond the original description].

    PubMed

    Avecillas-Chasín, Josué M; Matías-Guiu, Jordi A; Bautista-Balbás, Luis

    2015-07-16

    Introduccion. La encefalopatia posterior reversible (EPR) es una entidad clinicorradiologica caracterizada tipicamente por cuadros de cefalea, alteraciones visuales y crisis epilepticas, asociada a edema vasogeno corticosubcortical reversible en la neuroimagen. Objetivo. Presentar una revision de los aspectos fisiopatologicos de esta entidad y tambien de las asociaciones de la EPR descritas en la bibliografia. Desarrollo. Existe una serie de factores desencadenantes bien conocidos, como las crisis hipertensivas, la eclampsia o ciertos medicamentos. La descripcion de cada vez mas casos atipicos desde un punto de vista clinico y radiologico, asi como de posibles nuevos factores desencadenantes, obliga a una redefinicion de la entidad. Conclusiones. La EPR es un conjunto de manifestaciones clinicas y radiologicas que no se pueden enmarcar dentro la palabra 'sindrome'. Aunque la EPR se ha comunicado como irreversible en ciertos casos, el concepto de reversibilidad debe mantenerse en la definicion de esta entidad, ya que, en la mayor parte de los casos, el rapido control de la condicion desencadenante de la EPR permite la reversibilidad de las lesiones.

  12. Dynamic properties of the posterior cricoarytenoid muscle.

    PubMed

    Cooper, D S; Shindo, M; Sinha, U; Hast, M H; Rice, D H

    1994-12-01

    The aim of this research was to investigate the contractile properties of the posterior cricoarytenoid (PCA) muscle. Simultaneous measurements were made of the isometric force, temperature, and electromyographic activity of the dorsal cricoarytenoid muscle of anesthetized dogs during supramaximal stimulation of the recurrent laryngeal nerve for twitch and tetanic contraction. The conduction delay between stimulation of the recurrent nerve at the level of the larynx and the onset of the muscle action potential averaged 2.0 +/- 0.2 milliseconds (ms), and the latent period between the onset of electrical activity of the muscle and the onset of contraction had a mean duration of 3.3 +/- 0.8 ms. The mean of isometric contraction times found was 33.3 +/- 2.0 ms, shorter than most previous studies of canine PCA muscle. Tetanic frequency defined as smooth contraction was higher than previous estimates. Considerations of scaling of physiological time based on animal mass were applied to analysis of the experimental findings to make possible systematic comparison of previous findings across species and animal size.

  13. Ganglion cysts of the posterior cruciate ligament.

    PubMed

    Shetty, Gautam M; Nha, Kyung Wook; Patil, Sachin P; Chae, Dong Ju; Kang, Ki Hoon; Yoon, Jung Ro; Choo, Suk Kyu; Yi, Jeong Woo; Kim, Ji Hoon; Baek, Jong Ryoon

    2008-08-01

    Ganglion cysts of the posterior cruciate ligament (PCL) are uncommon lesions found incidentally on MRI and arthroscopy. Twenty patients (11 males and nine females) with the mean age of 35 years presenting with a variety of knee signs and symptoms were found to have PCL cysts on MRI. Out of these, thirteen patients (65%) had isolated symptomatic PCL cysts and seven patients had associated chondral and meniscal lesions. Eight out of the 20 patients (40%) gave a history of antecedent trauma. On arthroscopy, the majority of the cysts were situated at the midsubstance of the ligament with inter-cruciate distension and no involvement of the substance of the ligament. The content of the cysts varied with the majority having yellowish viscous fluid and three containing serous and bloody fluid. All cysts were successfully treated arthroscopically through standard anterior, posteromedial and posterolateral portals with no signs of recurrence on MRI at a mean followup of 24 months. PCL cysts may clinically mimic meniscal or chondral lesions and preoperatively, MRI is essential for the diagnosis of ganglion cysts arising from the PCL. Ganglion cysts of the PCL can be successfully treated arthroscopically using standard portals.

  14. Avulsion of both posterior meniscal roots associated with acute rupture of the anterior cruciate ligament.

    PubMed

    Mariani, Pier Paolo; Iannella, Germano; Cerullo, Guglielmo; Giacobbe, Marco

    2015-09-01

    A rare case of acute avulsion of both posterior meniscal roots concomitant with an acute anterior cruciate ligament (ACL) tear in a professional soccer player is described. While avulsion of the lateral meniscal root has been extensively reported in association with ACL injuries, medial root avulsion has never been reported in association with acute ACL. A review of the video documentation of the match accident revealed the exact mechanism of injury was a forceful external rotation of the standing limb.

  15. Initial evaluation of posterior cruciate ligament injuries: history, physical examination, imaging studies, surgical and nonsurgical indications.

    PubMed

    Lopez-Vidriero, Emilio; Simon, David A; Johnson, Donald H

    2010-12-01

    Compared with anterior cruciate ligament injuries, posterior cruciate ligament injuries are a rare event. The mechanisms are predictable and a thorough physical examination is mandatory to rule out or define combined injury patterns. Stress radiography and magnetic resonance imaging studies are very helpful adjuncts. Acute and chronic injuries require slightly different approaches. As our understanding of normal and pathologic knee joint kinematics develops, nonoperative rehabilitation goals and operative techniques continue to evolve.

  16. Posterior Probability Matching and Human Perceptual Decision Making.

    PubMed

    Murray, Richard F; Patel, Khushbu; Yee, Alan

    2015-06-01

    Probability matching is a classic theory of decision making that was first developed in models of cognition. Posterior probability matching, a variant in which observers match their response probabilities to the posterior probability of each response being correct, is being used increasingly often in models of perception. However, little is known about whether posterior probability matching is consistent with the vast literature on vision and hearing that has developed within signal detection theory. Here we test posterior probability matching models using two tools from detection theory. First, we examine the models' performance in a two-pass experiment, where each block of trials is presented twice, and we measure the proportion of times that the model gives the same response twice to repeated stimuli. We show that at low performance levels, posterior probability matching models give highly inconsistent responses across repeated presentations of identical trials. We find that practised human observers are more consistent across repeated trials than these models predict, and we find some evidence that less practised observers more consistent as well. Second, we compare the performance of posterior probability matching models on a discrimination task to the performance of a theoretical ideal observer that achieves the best possible performance. We find that posterior probability matching is very inefficient at low-to-moderate performance levels, and that human observers can be more efficient than is ever possible according to posterior probability matching models. These findings support classic signal detection models, and rule out a broad class of posterior probability matching models for expert performance on perceptual tasks that range in complexity from contrast discrimination to symmetry detection. However, our findings leave open the possibility that inexperienced observers may show posterior probability matching behaviour, and our methods provide new tools

  17. Posterior Probability Matching and Human Perceptual Decision Making

    PubMed Central

    Murray, Richard F.; Patel, Khushbu; Yee, Alan

    2015-01-01

    Probability matching is a classic theory of decision making that was first developed in models of cognition. Posterior probability matching, a variant in which observers match their response probabilities to the posterior probability of each response being correct, is being used increasingly often in models of perception. However, little is known about whether posterior probability matching is consistent with the vast literature on vision and hearing that has developed within signal detection theory. Here we test posterior probability matching models using two tools from detection theory. First, we examine the models’ performance in a two-pass experiment, where each block of trials is presented twice, and we measure the proportion of times that the model gives the same response twice to repeated stimuli. We show that at low performance levels, posterior probability matching models give highly inconsistent responses across repeated presentations of identical trials. We find that practised human observers are more consistent across repeated trials than these models predict, and we find some evidence that less practised observers more consistent as well. Second, we compare the performance of posterior probability matching models on a discrimination task to the performance of a theoretical ideal observer that achieves the best possible performance. We find that posterior probability matching is very inefficient at low-to-moderate performance levels, and that human observers can be more efficient than is ever possible according to posterior probability matching models. These findings support classic signal detection models, and rule out a broad class of posterior probability matching models for expert performance on perceptual tasks that range in complexity from contrast discrimination to symmetry detection. However, our findings leave open the possibility that inexperienced observers may show posterior probability matching behaviour, and our methods provide new tools

  18. Posterior urethral valves: long-term outcome.

    PubMed

    Caione, Paolo; Nappo, Simona Gerocarni

    2011-10-01

    Posterior urethral valves represent the most common cause of bladder outlet obstruction in infancy that impairs renal and bladder function. Long-term outcome of patients with previous PUV is evaluated. Patients over 18 years of age, treated from 1982 to 1995 before the age of 3 years were considered. Previous surgery, renal function, bladder activity, urinary incontinence, and fertility/sexual activity were evaluated. Clinical interview, creatinine clearance, uroflowmetry with ultrasound post-void urine residue, and self-administered questionnaire were recorded. Out of 45 identified records, 24 patients (53.3%) accepted to be enrolled (age 18-34 years, mean 23 years). The mean follow-up was 19.5 years (16-30 years). Out of the 21 excluded patients, 20 did not reply to the clinical interview and 1 died at age of 6 years. All the 24 patients had early endoscopic section of PUV; nine also received transient ureterocutaneostomy or vesicostomy. Ureteroneocystostomy was performed in five patients and ureterocystoplasty with unilateral nephrectomy in two. At follow-up chronic renal failure was detected in 13 patients (54.1%) and 9 (37.5%) had arterial hypertension. End-stage renal disease developed in five patients (20.8%): three had successful renal transplantation and two were in dialysis. Lower urinary tract symptoms were present in seven patients (29.1%). No significant fertility deficit and sexual dysfunction were observed in 23 patients, while 1 patient was azoospermic. No paternity was reported so far. Long-term outcome of patients with previously treated PUV is mandatory. Kidney, bladder, and sexual functions should be monitored till adulthood to verify any modified behaviour.

  19. The language profile of Posterior Cortical Atrophy

    PubMed Central

    Crutch, Sebastian J.; Lehmann, Manja; Warren, Jason D.; Rohrer, Jonathan D.

    2015-01-01

    Background Posterior Cortical Atrophy (PCA) is typically considered to be a visual syndrome, primarily characterised by progressive impairment of visuoperceptual and visuospatial skills. However patients commonly describe early difficulties with word retrieval. This paper details the first systematic analysis of linguistic function in PCA. Characterising and quantifying the aphasia associated with PCA is important for clarifying diagnostic and selection criteria for clinical and research studies. Methods Fifteen patients with PCA, 7 patients with logopenic/phonological aphasia (LPA) and 18 age-matched healthy participants completed a detailed battery of linguistic tests evaluating auditory input processing, repetition and working memory, lexical and grammatical comprehension, single word retrieval and fluency, and spontaneous speech. Results Relative to healthy controls, PCA patients exhibited language impairments across all the domains examined, but with anomia, reduced phonemic fluency and slowed speech rate the most prominent deficits. PCA performance most closely resembled that of LPA patients on tests of auditory input processing, repetition and digit span, but was relatively stronger on tasks of comprehension and spontaneous speech. Conclusions The study demonstrates that in addition to the well-reported degradation of vision, literacy and numeracy, PCA is characterised by a progressive oral language dysfunction with prominent word retrieval difficulties. Overlap in the linguistic profiles of PCA and LPA, which are both most commonly caused by Alzheimer’s disease, further emphasises the notion of a phenotypic continuum between typical and atypical manifestations of the disease. Clarifying the boundaries between AD phenotypes has important implications for diagnosis, clinical trial recruitment and investigations into biological factors driving phenotypic heterogeneity in AD. Rehabilitation strategies to ameliorate the phonological deficit in PCA are required

  20. Posterior ankle impingement syndrome: A systematic four-stage approach

    PubMed Central

    Yasui, Youichi; Hannon, Charles P; Hurley, Eoghan; Kennedy, John G

    2016-01-01

    Posterior ankle impingement syndrome (PAIS) is a common injury in athletes engaging in repetitive plantarflexion, particularly ballet dancers and soccer players. Despite the increase in popularity of the posterior two-portal hindfoot approach, concerns with the technique remain, including; the technical difficulty, relatively steep learning curve, and difficulty performing simultaneous anterior ankle arthroscopy. The purpose of the current literature review is to provide comprehensive knowledge about PAIS, and to describe a systematic four-stage approach of the posterior two-portal arthroscopy. The etiology, clinical presentation, diagnostic strategies are first introduced followed by options in conservative and surgical management. A detailed systematic approach to posterior hindfoot arthroscopy is then described. This technique allows for systematic review of the anatomic structures and treatment of the bony and/or soft tissue lesions in four regions of interest in the hindfoot (superolateral, superomedial, inferomedial, and inferolateral). The review then discusses biological adjuncts and postoperative rehabilitation and ends with a discussion on the most recent clinical outcomes after posterior hindfoot arthroscopy for PAIS. Although clinical evidence suggests high success rates following posterior hindfoot arthroscopy in the short- and mid-term it may be limited in the pathology that can be addressed due to the technical skills required, but the systematic four-stage approach of the posterior two-portal arthroscopy may improve upon this problem. PMID:27795947

  1. Neural correlates of cognitive impairment in posterior cortical atrophy.

    PubMed

    Kas, Aurélie; de Souza, Leonardo Cruz; Samri, Dalila; Bartolomeo, Paolo; Lacomblez, Lucette; Kalafat, Michel; Migliaccio, Raffaella; Thiebaut de Schotten, Michel; Cohen, Laurent; Dubois, Bruno; Habert, Marie-Odile; Sarazin, Marie

    2011-05-01

    With the prospect of disease-modifying drugs that will target the physiopathological process of Alzheimer's disease, it is now crucial to increase the understanding of the atypical focal presentations of Alzheimer's disease, such as posterior cortical atrophy. This study aimed to (i) characterize the brain perfusion profile in posterior cortical atrophy using regions of interest and a voxel-based approach; (ii) study the influence of the disease duration on the clinical and imaging profiles; and (iii) explore the correlations between brain perfusion and cognitive deficits. Thirty-nine patients with posterior cortical atrophy underwent a specific battery of neuropsychological tests, mainly targeting visuospatial functions, and a brain perfusion scintigraphy with 99mTc-ethyl cysteinate dimer. The imaging analysis included a comparison with a group of 24 patients with Alzheimer's disease, matched for age, disease duration and Mini-Mental State Examination, and 24 healthy controls. The single-photon emission computed tomography profile in patients with posterior cortical atrophy was characterized by extensive and severe hypoperfusion in the occipital, parietal, posterior temporal cortices and in a smaller cortical area corresponding to the frontal eye fields (Brodmann areas 6/8). Compared with patients with Alzheimer's disease, the group with posterior cortical atrophy showed more severe occipitoparietal hypoperfusion and higher perfusion in the frontal, anterior cingulate and mesiotemporal regions. When considering the disease duration, the functional changes began and remained centred on the posterior lobes, even in the late stage. Correlation analyses of brain perfusion and neuropsychological scores in posterior cortical atrophy highlighted the prominent role of left inferior parietal damage in acalculia, Gerstmann's syndrome, left-right indistinction and limb apraxia, whereas damage to the bilateral dorsal occipitoparietal regions appeared to be involved in B

  2. In vitro wear of flowable resin composite for posterior restorations.

    PubMed

    Shinkai, Koichi; Taira, Yoshihisa; Suzuki, Shiro; Suzuki, Masaya

    2016-01-01

    The purpose of this study was to examine three- and two-body wear values of flowable resin composites for posterior restorations, using a mechanical loading device. The cavities prepared on flattened extracted molars were restored with flowable resin composites (Clearfil Majesty LV: MLV, Estelite Flow Quick: EFQ, Beautifil Flow Plus F00: BFP, and MI Fill: MIF) using accompanying adhesive systems. A universal resin composite (Clearfil Majesty) was used as a control. The specimens were subjected to in vitro three- and two-body wear testing. MLV showed high wear value (three-body: 14.69 µm, two-body: 0.268 mm(3)) compared with other materials tested in both three- and two-body wear tests. BFP showed high three-body wear value (5.78 µm), whereas low two-body wear value (0.008 mm(3)). MIF and EFQ showed equivalent wear values (MIF, three-body: 0.42 µm, two-body: 0.026 mm(3); EFQ, three-body: 1.15 µm, two-body: 0.14 mm(3)) to that of the control in both wear tests.

  3. Posterior tibial nerve stimulation as treatment for the overactive bladder

    PubMed Central

    Sherif, Hammouda; Abdelwahab, Osama

    2013-01-01

    Objective To evaluate the efficacy of posterior tibial nerve stimulation (PTNS) as a treatment for the overactive bladder (OAB) resistant to medical treatment. Patients and methods The study included 60 patients, comprising 55 women (92%) and five men (8%) with a mean (SD) age of 41.4 (10.8) years, who presented to the Urology Department of Benha University Hospital from June 2010 to October 2012. All patients were assessed initially by taking a history, a physical examination, urine analysis, routine laboratory investigations, and a urodynamic evaluation in the form of flowmetry, cystometry, and a pressure-flow study in some cases. A voiding diary (daytime and night-time frequency, voiding volume, and leakage episodes) was completed by all patients, and all underwent 12 sessions of PTNS using a personal computer-based system, and were reassessed after the sixth session, at the end of the course, and at 3 and 6 months after the last session, using the same methods as in the baseline visit. Results There was a statistically significant improvement in all the variables assessed. No infection or failure of the PTNS mechanism was detected while using the technique, but there were rare instances of minor bleeding and a temporary painful feeling at the insertion site. Conclusion PTNS is safe, and gives statistically significant improvements in the patient’s assessment of OAB symptoms. PMID:26558070

  4. The posterior parietal cortex remaps touch into external space.

    PubMed

    Azañón, Elena; Longo, Matthew R; Soto-Faraco, Salvador; Haggard, Patrick

    2010-07-27

    Localizing tactile events in external space is required for essential functions such as orienting, haptic exploration, and goal-directed action in peripersonal space. In order to map somatosensory input into a spatiotopic representation, information about skin location must be integrated with proprioceptive information about body posture. We investigated the neural bases of this tactile remapping mechanism in humans by disrupting neural activity in the putative human homolog of the monkey ventral intraparietal area (hVIP), within the right posterior parietal cortex (rPPC), which is thought to house external spatial representations. Participants judged the elevation of touches on their (unseen) forearm relative to touches on their face. Arm posture was passively changed along the vertical axis, so that elevation judgments required the use of an external reference frame. Single-pulse transcranial magnetic stimulation (TMS) over the rPPC significantly impaired performance compared to a control site (vertex). Crucially, proprioceptive judgments of arm elevation or tactile localization on the skin remained unaffected by rPPC TMS. This selective disruption of tactile remapping suggests a distinct computational process dissociable from pure proprioceptive and somatosensory localization. Furthermore, this finding highlights the causal role of human PPC, putatively VIP, in remapping touch into external space.

  5. Detection of Neisseria gonorrhoeae Isolates from Tonsils and Posterior Oropharynx

    PubMed Central

    Whiley, D. M.; Lee, D. M.; Snow, A. F.; Fairley, C. K.; Peel, J.; Bradshaw, C. S.; Hocking, J. S.; Lahra, M. M.; Chen, M. Y.

    2015-01-01

    We examined the factors influencing gonorrhea detection at the pharynx. One hundred men infected with Neisseria gonorrhoeae were swabbed from the tonsils and posterior oropharynx. N. gonorrhoeae was reisolated from the tonsils and posterior oropharynx in 62% and 52%, respectively (P = 0.041). Culture positivity was greater with higher gonococcal DNA loads at the tonsils (P = 0.001) and oropharynx (P < 0.001). N. gonorrhoeae can be cultured from the tonsils and posterior oropharynx with greater isolation rates where gonococcal loads are higher. PMID:26292303

  6. Immunopathology of the noninfectious posterior and intermediate uveitides.

    PubMed

    Boyd, S R; Young, S; Lightman, S

    2001-01-01

    The posterior and intermediate uveitides share an underlying immune etiology; however, they can be clinically and immunopathologically distinguished. Although the initiating stimuli for posterior and intermediate uveities are not known, it is believed that an exogenous agent (such as a bacterium or a virus) or an endogenous molecule may induce disease. In either case, T-helper lymphocytes in conjunction with human leukocyte antigens are likely to be involved. This review examines the epidemiology, histology, immunopathology, and theories of pathogenesis of several posterior and intermediate uveitides, including sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, Behçet's disease, sarcoidosis, intermediate uveitis, white dot syndromes, and birdshot retinochoroidopathy.

  7. Posterior cortical atrophy: an atypical variant of Alzheimer disease.

    PubMed

    Suárez-González, Aida; Henley, Susie M; Walton, Jill; Crutch, Sebastian J

    2015-06-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by striking progressive visual impairment and a pattern of atrophy mainly involving posterior cortices. PCA is the most frequent atypical presentation of Alzheimer disease. The purpose of this article is to provide a summary of PCA's neuropsychiatric manifestations. Emotional and psychotic symptoms are discussed in the context of signal characteristic features of the PCA syndrome (the early onset, focal loss of visual perception, focal posterior brain atrophy) and the underlying cause of the disease. The authors' experience with psychotherapeutic intervention and PCA support groups is shared in detail.

  8. Incidence and surgical importance of the posterior gastric artery.

    PubMed Central

    Suzuki, K; Prates, J C; DiDio, L J

    1978-01-01

    In a series of 61 adult cadavers, the posterior gastric artery was found in 38 (62.3%), originating from the superior aspect of the mid-third of the splenic artery. The posterior gastric artery, running behind the parietal peritoneum of the omental bursa, produced a peritoneal fold before reaching the posterior wall of the superior portion of the gastric body, near the cardiac region, and the fundus. Its high incidence, hidden origin, deep course, and distribution make this artery very important for surgical procedures relating to the stomach, pancreas, spleen, and celiac region. It may be crucial, especially if partial gastric resection of splenectomy have obliterated other gastric vessels. PMID:629615

  9. Asystole during posterior fossa surgery: Report of two cases

    PubMed Central

    Goyal, Keshav; Philip, Frenny Ann; Rath, Girija Prasad; Mahajan, Charu; Sujatha, M.; Bharti, Sachidanand Jee; Gupta, Nidhi

    2012-01-01

    Asystole during posterior fossa neurosurgical procedures is not uncommon. Various causes have been implicated, especially when surgical manipulation is carried out in the vicinity of the brain stem. The trigemino-cardiac reflex has been attributed as one of the causes. Here, we report two cases who suffered asystole during the resection of posterior fossa tumors. The vago-glossopharyngeal reflex and the direct stimulation of the brainstem were hypothesized as the causes of asytole. These episodes resolved spontaneously following withdrawal of the surgical stimulus emphasizing the importance of anticipation and vigilance during critical moments of tumor dissection during posterior fossa surgery. PMID:22870159

  10. Ossification of the posterior longitudinal ligament: a case report

    PubMed Central

    Aker, PD; O’Connor, SM; Mior, SA; Beauchemin, D

    1989-01-01

    Ossification of the posterior longitudinal ligament (OPLL) has recently been recognized as a clinical entity. It is a rare condition, having a higher incidence in the Japanese population. It is characterized by hyperplasia of cartilage cells with eventual endochondral ossification of the posterior longitudinal ligament. The radiographic signs are characteristic and consist of a linear band of ossified tissue along the posterior margin of the vertebral body. OPLL can be associated with mild to serious neurological complications due to spinal cord or nerve root compression, or it may be asymptomatic. This paper reviews the radiological, clinical and therapeutic aspects of this rare condition. ImagesFigures 1 and 2Figures 3 and 4

  11. Posterior Wall Blowout in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Mitchell, Justin J.; Dean, Chase S.; Chahla, Jorge; Menge, Travis J.; Cram, Tyler R.; LaPrade, Robert F.

    2016-01-01

    Violation of the posterior femoral cortex, commonly referred to as posterior wall blowout, can be a devastating intraoperative complication in anterior cruciate ligament (ACL) reconstruction and lead to loss of graft fixation or early graft failure. If cortical blowout occurs despite careful planning and adherence to proper surgical technique, a thorough knowledge of the anatomy and alternative fixation techniques is imperative to ensure optimal patient outcomes. This article highlights anatomic considerations for femoral tunnel placement in ACL reconstruction and techniques for avoidance and salvage of a posterior wall blowout. PMID:27335885

  12. Sleep apnoea adversely affects the outcome in patients who undergo posterior lumbar fusion

    PubMed Central

    Stundner, O.; Chiu, Y-L.; Sun, X.; Ramachandran, S-K.; Gerner, P.; Vougioukas, V.; Mazumdar, M.; Memtsoudis, S. G.

    2014-01-01

    Despite the increasing prevalence of sleep apnoea, little information is available regarding its impact on the peri-operative outcome of patients undergoing posterior lumbar fusion. Using a national database, patients who underwent lumbar fusion between 2006 and 2010 were identified, sub-grouped by diagnosis of sleep apnoea and compared. The impact of sleep apnoea on various outcome measures was assessed by regression analysis. The records of 84 655 patients undergoing posterior lumbar fusion were identified and 7.28% also had a diagnostic code for sleep apnoea. Compared with patients without sleep apnoea, these patients were older, more frequently female, had a higher comorbidity burden and higher rates of peri-operative complications, post-operative mechanical ventilation, blood transfusion, and intensive care. Patients with sleep apnoea also had longer and more costly periods of hospitalisation. In the regression analysis, sleep apnoea emerged as an independent risk factor for the development of peri-operative complications (Odds Ratio (OR) 1.50, Confidence Interval (CI) 1.38;1.62), blood transfusions (OR 1.12, CI 1.03;1.23), mechanical ventilation (OR 6.97, CI 5.90;8.23), critical care services (OR 1.86, CI 1.71;2.03), prolonged hospitalisation and increased cost (OR 1.28, CI 1.19;1.37; OR 1.10, CI 1.03;1.18). Patients with sleep apnoea who undergo posterior lumbar fusion pose significant challenges to clinicians. PMID:24493191

  13. Posterior Structural Brain Volumes Differ in Maltreated Youth with and without Chronic Posttraumatic Stress Disorder

    PubMed Central

    Bellis, Michael D. De; Hooper, Stephen R.; Chen, Steven D.; Provenzale, James M.; Boyd, Brian D.; Glessner, Christopher E.; MacFall, James R.; Payne, Martha E.; Rybczynski, Robert; Woolley, Donald P

    2016-01-01

    Magnetic resonance imaging (MRI) studies of maltreated children with posttraumatic stress disorder (PTSD) suggest that maltreatment-related PTSD is associated with adverse brain development. Maltreated youth resilient to chronic PTSD were not previously investigated and may elucidate neuro-mechanisms of the stress diathesis that leads to resilience to chronic PTSD. In this cross-sectional study, anatomical volumetric and corpus callosum diffusion tensor imaging measures were examined using MRI in maltreated youth with chronic PTSD (N=38), without PTSD (N=35), and non-maltreated participants (n=59). Groups were sociodemographically similar. Participants underwent assessments for strict inclusion/exclusion criteria and psychopathology. Maltreated youth with PTSD were psychobiologically different from maltreated youth without PTSD and non-maltreated controls. Maltreated youth with PTSD had smaller posterior cerebral and cerebellar gray matter volumes than maltreated youth without PTSD and non-maltreated participants. Cerebral and cerebellar gray matter volumes inversely correlated with PTSD symptoms. Posterior corpus callosum microstructure in pediatric maltreatment-related PTSD differed compared to maltreated youth without PTSD and controls. The group differences remained significant when controlling for psychopathology, numbers of Axis I disorders, and trauma load. Alterations of these posterior brain structures may result from a shared trauma related-mechanism or an inherent vulnerability that mediates the pathway from chronic PTSD to co-morbidity. PMID:26535944

  14. Grapheme-color synesthesia subtypes: Stable individual differences reflected in posterior alpha-band oscillations.

    PubMed

    Cohen, Michael X; Weidacker, Kathrin; Tankink, Judith; Scholte, H Steven; Rouw, Romke

    2015-01-01

    Grapheme-color synesthesia is a condition in which seeing letters and numbers produces sensations of colors (e.g., the letter R may elicit a sky-blue percept). Recent evidence implicates posterior parietal areas, in addition to lower-level sensory processing regions, in the neurobiological mechanisms involved in synesthesia. Furthermore, these mechanisms seem to differ for "projectors" (synesthetes who report seeing the color "out there in the real world") versus "associators" (synesthetes who report the color to be only an internal experience). Relatively little is known about possible electrophysiological characteristics of grapheme-color synesthesia. Here we used EEG to investigate functional oscillatory differences among associators, projectors, and non-synesthetes. Projectors had stronger stimulus-related alpha-band (~10 Hz) power over posterior parietal electrodes, compared to both associators and non-synesthetes. Posterior alpha activity was not statistically significantly different between associators from non-synesthetes. We also performed a test-retest assessment of the projector-associator score and found strong retest reliability, as evidenced by a correlation coefficient of .85. These findings demonstrate that the projector-associator distinction is highly reliable over time and is related to neural oscillations in the alpha band.

  15. Identification and transcriptional profile of multiple genes in the posterior kidney of Nile tilapia at 6h post bacterial infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophi...

  16. The overlooked side of convulsion: bilateral posterior fracture and dislocation of proximal humerus.

    PubMed

    Yigit, Mehmet; Yaman, Asli; Yigit, Eda; Turkdogan, Kenan Ahmet

    2016-05-01

    Injuries after an epileptic convulsion have been seen commonly such as burns, head injury and dislocation of the extremities. But fractures of the extremities due to convulsion are rare. External trauma mechanism is not necessary for extremity fractures. Muscle contractions can cause increased load on the skeleton and it can be complicated by dislocation andor fracture of extremities. Almost 1-4% of all the shoulder dislocations are posterior. In this case report we present a 32 year old male patient who had bilateral posterior fracture and dislocation of proximal humerus after convulsion. We would like to emphasize that it is so important to make systemic examination and evaluation of the patients who were admitted to emergency department after epileptic convulsion.

  17. Rhinocerebral mucormycosis with extension to the posterior fossa: case report.

    PubMed

    Soloniuk, D S; Moreland, D B

    1988-11-01

    A 25-year-old man with juvenile onset diabetes presented with rhinoorbital mucormycosis. He was treated aggressively with orbital extirpation and amphotericin B. Six months later, he presented with posterior fossa extension of the mucormycosis.

  18. Modified posterior vertebral column resection for Kümmell disease

    PubMed Central

    Liu, Feng-Yu; Huo, Li-Shuang; Liu, Sen; Wang, Hui; Zhang, Li-Jun; Yang, Da-Long; Ding, Wen-Yuan

    2017-01-01

    Abstract Rationale: Kümmell's disease is defined as delayed traumatic vertebral collapse disease in which patients develop a kyphosis after asymptomatic minor spinal trauma. Both anterior approach and posterior approach have been reported, however, there is no standard treatment for Kümmell's disease. Patient concerns: We described a successful modified posterior vertebral column resection in a patient with Kümmell's disease. A 65-year-old woman reported persistent back pain for almost three months. Diagnoses: Kümmell's disease was diagnosed based on computer tomography (CT) and magnetic resonance imaging (MRI). Interventions: Modified posterior vertebral column resection combined with short-segment fixation was designed to treat this disease. Outcomes: The procedure was successful without any complications. Patient reported that symptoms were obviously improved in one week after operation. Lessons: Modified posterior vertebral column resection combined with short-segment fixation is an effective treatment option for Kümmell's disease. PMID:28151882

  19. Aneurysms of the posterior cerebral artery in children.

    PubMed

    Romero, F J; Tàpies, C; Ibarra, B; Rovira, M

    1988-01-01

    Two cases of aneurysms of the posterior cerebral artery, diagnosed by CT and confirmed angiographically, are reported. In the first case, the aneurysm was discovered fortuitously. The second began with intracerebral haemorrhage. A review of the literature is reported.

  20. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery.

    PubMed

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-12-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as "resection at an anterior site of the spinal cord from a posterior approach" (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis.

  1. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery

    PubMed Central

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-01-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as “resection at an anterior site of the spinal cord from a posterior approach” (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis. PMID:27853667

  2. The influence of posterior occlusion when restoring anterior teeth.

    PubMed

    Reshad, Mamaly; Jivraj, Sajid

    2008-08-01

    When any type of esthetic restorative procedure is being considered or performed, a comprehensive diagnosis and treatment plan is required. Attention to the diagnostic signs of the loss of posterior support (LPS) and their influence on the anterior dentition will guarantee a more predictable outcome. Historical solutions and their inadequacies are addressed. Patient presentations are utilized to demonstrate contemporary treatment of patients requiring esthetic rehabilitations who are lacking posterior support.

  3. Parascapular mass revealing primary tuberculosis of the posterior arch

    PubMed Central

    Arbault, Anais; Ornetti, Paul; Chevallier, Olivier; Avril, Julien; Pottecher, Pierre

    2016-01-01

    We report the case of a parascapular abscess revealing primary tuberculosis of the posterior arch in a 31-year-old man. Sectional imaging is essential in order to detect the different lesions of this atypical spinal tuberculosis as osteolysis of the posterior arch extendible to vertebral body, osteocondensation, epidural extension which is common in this location, and high specificity of a zygapophysial, costo-vertebral or transverse arthritis. PMID:27709081

  4. [Tuberculosis of the posterior vertebral arch. A case report].

    PubMed

    Nassar, I; Mahi, M; Semlali, S; Kacemi, L; El Quessar, A; Chakir, N; El Hassani, M R; Jiddane, M

    2002-09-01

    Tuberculosis of the spine usually involves the vertebral body and intervertebral disk. Involvement of the posterior arch is rare. We report a case of tuberculosis involving the posterior elements of the T4 and T5 vertebrae in a 38 year old woman. CT is helpful to assess bony structures whereas MRI is ideal to evaluate the neural structures. Clinical, radiographic, and therapeutic considerations regarding tuberculosis of the spine are reviewed.

  5. Brainstem variant of posterior reversible encephalopathy syndrome: A case report

    PubMed Central

    Caranci, Ferdinando; Belfiore, Maria Paola; Manzi, Francesca; Pagliano, Pasquale; Cirillo, Sossio

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological condition, generally observed in conjunction with severe and acute hypertension, that involves mainly the posterior head areas (occipital and temporal lobes) and anterior “watershed” areas. In this syndrome it is rare to observe a predominant involvement of the brainstem. We describe the clinical and radiological findings in a patient with brainstem involvement, discussing its pathophysiological features and possible differential diagnosis. PMID:26515750

  6. Brainstem variant of posterior reversible encephalopathy syndrome: A case report.

    PubMed

    Tortora, Fabio; Caranci, Ferdinando; Belfiore, Maria Paola; Manzi, Francesca; Pagliano, Pasquale; Cirillo, Sossio

    2015-12-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological condition, generally observed in conjunction with severe and acute hypertension, that involves mainly the posterior head areas (occipital and temporal lobes) and anterior "watershed" areas. In this syndrome it is rare to observe a predominant involvement of the brainstem. We describe the clinical and radiological findings in a patient with brainstem involvement, discussing its pathophysiological features and possible differential diagnosis.

  7. Posterior polymorphous dystrophy and keratoglobus in a child.

    PubMed

    Patel, Sangita P; Sajnani, Manoj M; Pineda, Roberto

    2011-01-01

    A 13-year-old boy presented with gradually progressive deterioration of vision in both eyes, bilateral photophobia, and regular headaches. Clinical examination, anterior segment findings, and specular microscopy findings were consistent with the diagnosis of posterior polymorphous dystrophy and keratoglobus. To the authors' knowledge, this is the first pediatric case and the second case overall of the simultaneous occurrence of posterior polymorphous dystrophy and keratoglobus.

  8. Complementary expression of EphA7 and SCO-spondin during posterior commissure development

    PubMed Central

    Stanic, Karen; Vera, América; González, Melissa; Recabal, Antonia; Astuya, Allison; Torrejón, Marcela; Montecinos, Hernán; Caprile, Teresa

    2014-01-01

    Bilaterally symmetric organisms need to exchange information between the two sides of their bodies in order to integrate sensory inputs and coordinate motor control. This exchange occurs through commissures formed by neurons that project axons across the midline to the contralateral side of the central nervous system. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. It is located in the dorsal portion of the prosomere 1, at the caudal diencephalon. The axons of the posterior commissure principally come from neurons of ventrolateral and dorsolateral pretectal nuclei (parvocellular and magnocellular nucleus of the posterior commissure, respectively) that extend their axons toward the dorsal region. The trajectory of these axons can be divided into the following three stages: (1) dorsal axon extension towards the lateral roof plate; (2) fasciculation in the lateral roof plate; and (3) midline decision of turning to the ipsilateral side or continuing to the opposite side. The mechanisms and molecules that guide the axons during these steps are unknown. In the present work, immunohistochemical and in situ hybridization analyses were performed, with results suggesting the participation of EphA7 in guiding axons from the ventral to the dorsal region of the prosomere 1 through the generation of an axonal corridor limited by repulsive EphA7 walls. At the lateral roof plate, the axons became fasciculated in presence of SCO-spondin until reaching the midline. Finally, EphA7 expression was observed in the diencephalic midline roof plate, specifically in the region where some axons turn to the ipsilateral side, suggesting its participation in this decision. In summary, the present work proposes a mechanism of posterior commissure formation orchestrated by the complementary expression of the axon guidance cues SCO-spondin and EphA7. PMID:25009468

  9. Imaging in spinal posterior epidural space lesions: A pictorial essay.

    PubMed

    Gala, Foram B; Aswani, Yashant

    2016-01-01

    Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication.

  10. Optimizing tooth form with direct posterior composite restorations

    PubMed Central

    Raghu, Ramya; Srinivasan, Raghu

    2011-01-01

    Advances in material sciences and technology have provided today's clinicians the strategies to transform the mechanistic approach of operative dentistry into a biologic philosophy. In the last three decades, composite resins have gone from being just an esthetically pleasing way of restoring Class III and Class IV cavities to become the universal material for both anterior and posterior situations as they closely mimic the natural esthetics while restoring the form of the human dentition. In order to enhance their success, clinicians have to rethink their protocol instead of applying the same restorative concepts and principles practiced with metallic restorations. Paralleling the evolution of posterior composite resin materials, cavity designs, restorative techniques and armamentarium have also developed rapidly to successfully employ composite resins in Class II situations. Most of the earlier problems with posterior composites such as poor wear resistance, polymerization shrinkage, postoperative sensitivity, predictable bonding to dentin, etc., have been overcome to a major extent. However, the clinically relevant aspect of achieving tight contacts in Class II situations has challenged clinicians the most. This paper reviews the evolution of techniques and recent developments in achieving predictable contacts with posterior composites. A Medline search was performed for articles on “direct posterior composite contacts.” The keywords used were “contacts and contours of posterior composites.” The reference list of each article was manually checked for additional articles of relevance. PMID:22144797

  11. Imaging in spinal posterior epidural space lesions: A pictorial essay

    PubMed Central

    Gala, Foram B; Aswani, Yashant

    2016-01-01

    Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication. PMID:27857455

  12. Traumatic posterior communicating artery-cavernous fistula, angioarchitecture, and possible pathogenesis: a case report and literature review

    PubMed Central

    Du, Bin; Zhang, Meng; Liu, Qing-Lin; Shen, Jie; Wang, Yun-Yan

    2016-01-01

    Carotid-cavernous fistulas (CCFs) are an abnormal vascular shunt between the carotid artery and the cavernous sinus, and were traditionally classified into four subtypes based on the detailed fistulas anatomy and arterial supply. CCFs are frequently encountered in patients with traumatic skull base fractures. In this report, we present one such case caused by two head traumas. Computed tomography and digital subtraction angiography confirmed that this CCF arose from posterior communicating artery of the internal carotid artery, which is not included in the traditional Barrow et al’s categorization. The possible mechanisms include laceration of dural mater of posterior clinoid process and laceration or pseudoaneurysm formation of posterior communicating artery. This case was successfully treated with endovascular coil embolization. PMID:27099501

  13. One step arthroscopically assisted Latarjet and posterior bone-block, for recurrent posterior instability and anterior traumatic dislocation

    PubMed Central

    D’Ambrosi, Riccardo; Perfetti, Carlo; Garavaglia, Guido; Taverna, Ettore

    2015-01-01

    This case presents the challenges of the surgical management for a patient with a history of recurrent posterior shoulder instability and subsequently traumatic anterior dislocation. The patient was already on the waiting list for an arthroscopic posterior stabilization with anchors, when a car accident caused an additional anterior shoulder dislocation. This traumatic anterior dislocation created a bone loss with a glenoid fracture and aggravated the preexisting posterior instability. In order to address both problems, we decided to perform an arthroscopically assisted Latarjet procedure for anterior instability and to stabilize with a bone graft for posterior instability. To our best knowledge, this type of surgical procedure has so far never been reported in the literature. The purpose of this report is to present the surgical technique and to outline the decision making process. PMID:26288539

  14. Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis

    PubMed Central

    Huang, Yun-Peng; Du, Cheng-Fei; Cheng, Cheng-Kung; Zhong, Zheng-Cheng; Chen, Xuan-Wei; Wu, Gui; Li, Zhe-Cheng; Ye, Jin-Duo; Lin, Jian-Hua; Wang, Li Zhen

    2016-01-01

    Objective To investigate the biomechanical effects of the lumbar posterior complex on the adjacent segments after posterior lumbar interbody fusion (PLIF) surgeries. Methods A finite element model of the L1–S1 segment was modified to simulate PLIF with total laminectomy (PLIF-LAM) and PLIF with hemilaminectomy (PLIF-HEMI) procedures. The models were subjected to a 400N follower load with a 7.5-N.m moment of flexion, extension, torsion, and lateral bending. The range of motion (ROM), intradiscal pressure (IDP), and ligament force were compared. Results In Flexion, the ROM, IDP and ligament force of posterior longitudinal ligament, intertransverse ligament, and capsular ligament remarkably increased at the proximal adjacent segment in the PLIF-LAM model, and slightly increased in the PLIF-HEMI model. There was almost no difference for the ROM, IDP and ligament force at L5-S1 level between the two PLIF models although the ligament forces of ligamenta flava remarkably increased compared with the intact lumbar spine (INT) model. For the other loading conditions, these two models almost showed no difference in ROM, IDP and ligament force on the adjacent discs. Conclusions Preserved posterior complex acts as the posterior tension band during PLIF surgery and results in less ROM, IDP and ligament forces on the proximal adjacent segment in flexion. Preserving the posterior complex during decompression can be effective on preventing adjacent segment degeneration (ASD) following PLIF surgeries. PMID:27870867

  15. C7 pars fracture subadjacent to C7 pedicle screw instrumentation at the caudal end of a posterior cervical instrumentation construct.

    PubMed

    Halim, Andrea; Grauer, Jonathan

    2014-07-01

    We report a case of a C7 pars fracture subadjacent to C7 pedicle screw instrumentation at the caudal end of posterior cervical instrumentation construct. To date, posterior cervical instrumentation has been "off label"; however, the US Food and Drug Administration is considering approving label indication of such instrumentation for this common surgical practice. Complications related to the techniques are reported to be relatively low. We know of no previous reports of pars fractures occurring subadjacent to such instrumentation. A 43-year-old man underwent posterior C5-C7 instrumented fusion. Postoperatively, the patient experienced cervical spine injury after a mechanical fall down stairs. Work-up detected bilateral C7 pars fractures subadjacent to the posterior instrumentation construct. After we treated the pars fracture with distal extension of the posterior fusion to the level of T2, the patient progressed to union and marked improvement of initial clinical symptoms that was maintained 2.5 years after posterior instrumentation. To our knowledge, a C7 pars fracture subadjacent to posterior cervical instrumentation construct has not been reported. We hypothesize that the pars may have been vulnerable to fracture because of excessive bone resection during foraminotomy or decortication. This complication was successfully treated by extending the fusion caudally.

  16. Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis.

    PubMed

    Farrokhi, Majid Reza; Rahmanian, Abdolkarim; Masoudi, Mohammad Sadegh

    2012-05-20

    Spondylolisthesis is a heterogeneous disorder characterized by subluxation of a vertebral body over another in the sagittal plane. Its most common form is isthmic spondylolisthesis (IS). This study aims to compare clinical outcomes of posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF) with posterior instrumentation in the treatment of IS. We performed a randomized prospective study in which 80 patients out of a total of 85 patients with IS were randomly allocated to one of two groups: PLF with posterior instrumentation (group I) or PLIF with posterior instrumentation (group II). Posterior decompression was performed in the patients. The Oswestry low back pain disability (OLBP) scale and Visual Analogue Scale (VAS) were used to evaluate the quality of life (QoL) and pain, respectively. Fisher's exact test was used to evaluate fusion rate and the Mann-Whitney U test was used to compare categorical data. Fusion in group II was significantly better than in group I (p=0.012). Improvement in low back pain was statistically more significant in group I (p=0.001). The incidence of neurogenic claudication was significantly lower in group I than in group II (p=0.004). In group I, there was no significant correlation between slip Meyerding grade and disc space height, radicular pain, and low back pain. There was no significant difference in post-operative complications at 1-year follow-up. Our data showed that PLF with posterior instrumentation provides better clinical outcomes and more improvement in low back pain compared to PLIF with posterior instrumentation despite the low fusion rate.

  17. Interoceptive awareness changes the posterior insula functional connectivity profile.

    PubMed

    Kuehn, Esther; Mueller, Karsten; Lohmann, Gabriele; Schuetz-Bosbach, Simone

    2016-04-01

    Interoceptive awareness describes the ability to consciously perceive inner bodily signals, such as one's own heartbeat. The right anterior insula is assumed to mediate this ability. The role of the posterior insula, particularly posterior-to-anterior insula signal flows is less clear in this respect. We scanned 27 healthy people with either high or low interoceptive awareness using 3T fMRI, while they either monitored their own heartbeats, or external tones, respectively. We used a combination of network centrality and bivariate connectivity analyses to characterize changes in cortical signal flows between the posterior insula and the anterior insula during interoceptive awareness or exteroceptive awareness, respectively. We show that heartbeat monitoring was accompanied by reduced network centrality of the right posterior insula, and decreased functional connectivity strengths between the right posterior insula and the right mid and anterior insula. In addition, decreased signal flows between the right posterior insula and the bilateral anterior cingulate cortices, and the bilateral orbitofrontal cortices were observed during interoceptive awareness. Functional connectivity changes were only shown by people with high interoceptive awareness, and occurred specifically within the low-frequency range (i.e., <0.1 Hz). Both groups did not differ in their functional connectivity profiles during rest. Our results show for the first time that interoceptive awareness changes intra-insula signal flows in the low-frequency range. We speculate that the selective inhibition of slow signal progression along the posterior-to-anterior insula pathway during interoceptive awareness allows the salient and noiseless detection of one's own heartbeat.

  18. Posterior scissors-bite: masticatory jaw movement and muscle activity.

    PubMed

    Tomonari, H; Kubota, T; Yagi, T; Kuninori, T; Kitashima, F; Uehara, S; Miyawaki, S

    2014-04-01

    Scissors-bite is a malocclusion characterised by buccal inclination or buccoversion of the maxillary posterior tooth and/or linguoclination or linguoversion of the mandibular posterior tooth. This type of malocclusion causes reduced contact of the occlusal surfaces and can cause excessive vertical overlapping of the posterior teeth. This case-control study is the first to evaluate both masticatory jaw movement and masseter and temporalis muscle activity in patients with unilateral posterior scissors-bite. Jaw movement variables and surface electromyography data were recorded in 30 adult patients with unilateral posterior scissors-bite malocclusion and 18 subjects with normal occlusion in a case-control study. The chewing pattern on the scissors-bite side significantly differed from that of the non-scissors-bite side in the patients and of the right side in the normal subjects. These differences included a narrower chewing pattern (closing angle, P < 0.01; cycle width, P < 0.01), a longer closing duration (P < 0.05), a slower closing velocity (P < 0.01) and lower activities of both the temporalis (P < 0.05) and the masseter (P < 0.05) muscles on the working side. In 96% of the patients with unilateral posterior scissors-bite, the preferred chewing side was the non-scissors-bite side (P = 0.005). These findings suggest that scissors-bite malocclusion is associated with the masticatory chewing pattern and muscle activity, involving the choice of the preferred chewing side in patients with unilateral posterior scissors-bite.

  19. Neptune is involved in posterior axis and tail formation in Xenopus embryogenesis.

    PubMed

    Takeda, Masatoshi; Kurauchi, Takayuki; Yamazaki, Takeshi; Izutsu, Yumi; Maéno, Mitsugu

    2005-09-01

    In order to elucidate the molecular mechanisms underlying the posterior axis and tail formation in embryogenesis, the function of Neptune, a zinc-finger transcription factor, in Xenopus laevis embryos was investigated. Injection of neptune mRNA into the animal pole area of embryos resulted in the formation of an additional tail structure that included a neural tube and muscle tissue. This activity required FGF signaling since coinjection of a dominant-negative FGF receptor RNA (XFD) completely blocked the formation of a tail structure. A loss-of-function experiment using a fusion construct of neptune and Drosophila engrailed (en-neptune) RNA showed that endogenous Neptune is necessary for formation of the posterior trunk and tail. Furthermore, activity of Neptune was necessary for the endogenous expression of brachyury and fgf-8 at the late gastrula stage. These findings demonstrate a novel function of Neptune in the process of anterior-posterior axis formation through the FGF and brachyury signaling cascades. An experiment using a combination explant with ventral and dorsal marginal tissues showed that cooperation of these two distinct tissues is important for the tail formation and that expression of Neptune in prospective ventral cells may be involved in the activation of the process of tail formation.

  20. Posterior ventricular restoration treatment for heart failure: a review, past, present and future aspects.

    PubMed

    Isomura, Tadashi; Fukada, Yasuhisa; Miyazaki, Takuya; Yoshida, Minoru; Morisaki, Akimasa; Endo, Masahiro

    2017-03-01

    Congestive heart failure (CHF) is one of the major causes of death and occurs in more than 15,000,000 patients worldwide. The incidence is expected to increase in parallel with the aging population. Most current therapies for CHF are medications, and biventricular pacing implantation as appropriated by cardiologists, or surgical interventions. The heart transplantation for indicated patients is still gold standard surgery although the 10-year survival rate is approximately 60% based on the worldwide data. However, the cardiac transplantation remains epidemiologically insignificant because of donor pool limitations. New strategies for treating CHF are needed. In addition to conventional cardiac surgery, surgical ventricular restoration was reported as a promising surgical therapy in 1990s. After the first report of partial left ventriculectomy in which posterior wall was widely resected for dilated heart, many controversial clinical and animal research studies have been reported. In this review, the principles of posterior cardiac restoration therapy will be discussed. An overview of posterior cardiac restoration, structure, and torsion are presented. By understanding the structure of cardiac muscle, shape, and torsion of left ventricle for surgical restoration, the procedure can be performed based on appropriate indication and this knowledge can be used to optimize and improve its efficacy. The use of mechanical support devices has recently become commonplace in many centers, and the use of implantable ventricular assist devices as destination therapy will increase. Surgeons will be able to select several options of the treatment for CHF by understanding the advantages and disadvantages of those surgical treatments.

  1. Porous Tantalum Buttress Augments for Severe Acetabular Posterior Column Deficiency.

    PubMed

    Meneghini, R Michael; Hull, Jason R; Russo, Glenn S; Lieberman, Jay R; Jiranek, William A

    2015-11-01

    In revision total hip arthroplasty (THA), consensus is lacking regarding the optimal method for reconstruction of the most severe acetabular defects. Porous tantalum (TM) buttress augments were designed for the most severe postero-superior defects. The purpose of this study was to report the results of a consecutive series of acetabular reconstructions utilizing TM buttress augments. Eight complex acetabular reconstructions utilizing a TM buttress augment were performed at two centers. All were Paprosky 3A or Paprosky 3B bone loss classification, with severe superior and posterior column deficiency where wedge augments were insufficient for mechanical support. The acetabular cup sizes ranged from 64-78, and a buttress shim was used in 7 of 8 cases. Clinical and radiographic follow-up averaged 16.5 months (range, 10-28) and no cases were lost to follow-up. There were no cases of clinical or radiographic loosening, and no case had required reoperation or revision. All patients except one were ambulating with either no assist device or a single cane at final follow-up. There was one complication of an iliac wing fracture noted incidentally on postoperative x-rays in the lone patient in whom a buttress shim was not used. At short-term follow-up, TM acetabular buttress augments appear to effectively substitute for the use of structural allografts or cages, which would otherwise be used in this challenging setting. The potential for biologic fixation is promising for the durability of these reconstructions; however, longer-term follow-up is required for full evaluation.

  2. Posterior Corneal Characteristics of Cataract Patients with High Myopia

    PubMed Central

    Jing, Qinghe; Tang, Yating; Qian, Dongjin; Lu, Yi; Jiang, Yongxiang

    2016-01-01

    Purpose To evaluate the characteristics of the posterior corneal surface in patients with high myopia before cataract surgery. Methods We performed a cross-sectional study at the Eye and ENT Hospital of Fudan University, Shanghai, China. Corneal astigmatism and axial length were measured with a rotating Scheimpflug camera (Pentacam) and partial coherence interferometry (IOLMaster) in a high-myopia study group of 167 eyes (axial length ≥ 26 mm) and a control group of 150 eyes (axial length > 20 mm and < 25 mm). Results Total corneal astigmatism and anterior corneal astigmatism values were higher in the high-myopia group than in the control group. There was no significant difference in posterior corneal astigmatism between the high-myopia study group and the control group. In the study group, the mean posterior corneal astigmatism (range 0 – −0.9 diopters) was –0.29 diopters (D) ± 0.17 standard deviations (SD). The steep corneal meridian was aligned vertically (60°–120°) in 87.43% of eyes for the posterior corneal surface, and did not change with increasing age. There was a significant correlation (r = 0.235, p = 0.002) between posterior corneal astigmatism and anterior corneal astigmatism, especially when the anterior corneal surface showed with-the-rule (WTR) astigmatism (r = 0.452, p = 0.000). There was a weak negative correlation between posterior corneal astigmatism and age (r = –0.15, p = 0.053) in the high-myopia group. Compared with total corneal astigmatism values, the anterior corneal measurements alone overestimated WTR astigmatism by a mean of 0.27 ± 0.18 D in 68.75% of eyes, underestimated against-the-rule (ATR) astigmatism by a mean of 0.41 ± 0.28 D in 88.89% of eyes, and underestimated oblique astigmatism by a mean of 0.24 ± 0.13 D in 63.64% of eyes. Conclusions Posterior corneal astigmatism decreased with age and remained as ATR astigmatism in most cases of high myopia. There was a significant correlation between posterior corneal

  3. Pseudomonas aeruginosa Survival at Posterior Contact Lens Surfaces after Daily Wear

    PubMed Central

    Wu, Yvonne T.; Zhu, Lucia S.; Tam, K. P. Connie; Evans, David J.; Fleiszig, Suzanne M. J.

    2015-01-01

    Purpose Pseudomonas aeruginosa keratitis is a sight-threatening complication of contact lens wear, yet mechanisms by which lenses predispose to infection remain unclear. Here, we tested the hypothesis that tear fluid at the posterior contact lens surface can lose antimicrobial activity over time during lens wear. Methods Daily disposable lenses were worn for 1, 2, 4, 6 or 8 h immediately after removal from their packaging, or after presoaking in sterile saline for 2 days to remove packaging solution. Unworn lenses were also tested, some coated in tears “aged” in vitro for 1 or 8 h. Lenses were placed anterior surface down into tryptic soy agar cradles containing gentamicin (100µg/ml) to kill bacteria already on the lens, and posterior surfaces inoculated with gentamicin-resistant P. aeruginosa for 3 h. Surviving bacteria were enumerated by viable counts of lens homogenates. Results Posterior surfaces of lenses worn by patients for 8 h supported more P. aeruginosa growth than lenses worn for only 1 h, if lenses were presoaked prior to wear (~ 2.4-fold, p = 0.01). This increase was offset if lenses were not presoaked to remove packaging solution (p = 0.04 at 2 h and 4 h). Irrespective of presoaking, lenses worn for 8 h showed more growth on their posterior surface than unworn lenses coated with tear fluid that was “aged” for 8 h vitro (~8.6-fold, presoaked, p = 0.003: ~ 5.4-fold from packaging solution, p = 0.004). Indeed, in vitro incubation did not impact tear antimicrobial activity. Conclusions This study shows that post lens tear fluid can lose antimicrobial activity over time during contact lens wear, supporting the idea that efficient tear exchange under a lens is critical for homeostasis. Additional studies are needed to determine applicability to other lens types, wearing modalities, and relevance to contact lens-related infections. PMID:25955639

  4. Posterior predictive modeling using multi-scale stochastic inverse parameter estimates.

    SciTech Connect

    Waanders, Bart Van Bloemen; Marzouk, Youssef M.; Ray, Jaideep; McKenna, Sean Andrew

    2010-12-01

    Multi-scale binary permeability field estimation from static and dynamic data is completed using Markov Chain Monte Carlo (MCMC) sampling. The binary permeability field is defined as high permeability inclusions within a lower permeability matrix. Static data are obtained as measurements of permeability with support consistent to the coarse scale discretization. Dynamic data are advective travel times along streamlines calculated through a fine-scale field and averaged for each observation point at the coarse scale. Parameters estimated at the coarse scale (30 x 20 grid) are the spatially varying proportion of the high permeability phase and the inclusion length and aspect ratio of the high permeability inclusions. From the non-parametric, posterior distributions estimated for these parameters, a recently developed sub-grid algorithm is employed to create an ensemble of realizations representing the fine-scale (3000 x 2000), binary permeability field. Each fine-scale ensemble member is instantiated by convolution of an uncorrelated multiGaussian random field with a Gaussian kernel defined by the estimated inclusion length and aspect ratio. Since the multiGaussian random field is itself a realization of a stochastic process, the procedure for generating fine-scale binary permeability field realizations is also stochastic. Two different methods are hypothesized to perform posterior predictive tests. Different mechanisms for combining multi Gaussian random fields with kernels defined from the MCMC sampling are examined. Posterior predictive accuracy of the estimated parameters is assessed against a simulated ground truth for predictions at both the coarse scale (effective permeabilities) and at the fine scale (advective travel time distributions). The two techniques for conducting posterior predictive tests are compared by their ability to recover the static and dynamic data. The skill of the inference and the method for generating fine-scale binary permeability

  5. Treatment of noninfectious posterior uveitis with dexamethasone intravitreal implant

    PubMed Central

    Myung, Jane S; Aaker, Grant D; Kiss, Szilárd

    2010-01-01

    Purpose To report our experience with dexamethasone 0.7 mg sustained-release intravitreal implant (Ozurdex®; Allergan, Inc, Irvine, CA) in noninfectious posterior uveitis. Methods A retrospective chart review of patients with noninfectious uveitis treated with sustained-release dexamethasone 0.7 mg intravitreal implant was performed. Complete ophthalmic examination including signs of inflammatory activity, visual acuity, fundus photography, fluorescein angiography, optical coherence tomography, and tolerability of the implant were assessed. Results Six eyes of 4 consecutive patients treated with a total of 8 dexamethasone 0.7 mg sustained-release intravitreal implants for posterior noninfectious uveitis were included. Two patients presented with unilateral idiopathic posterior uveitis; 2 patients had bilateral posterior uveitis, one secondary to sarcoidosis and the other to Vogt-Koyanagi-Harada syndrome. All eyes showed clinical and angiographic evidence of decreased inflammation following implant placement. Mean follow-up time post-injection was 5.25 months. Four eyes received 1 and 2 eyes received 2 Ozurdex implants during the follow-up period. The duration of effect of the implant was 3 to 4 months. No serious ocular or systemic adverse events were noted during the follow-up period. Conclusions In patients with noninfectious posterior uveitis, sustained-release dexamethasone 0.7 mg intravitreal implant may be an effective treatment option for controlling intraocular inflammation. PMID:21188153

  6. Flexor Digitorum Accessorius Longus: Importance of Posterior Ankle Endoscopy

    PubMed Central

    Batista, Jorge Pablo; del Vecchio, Jorge Javier; Golanó, Pau; Vega, Jordi

    2015-01-01

    Endoscopy for the posterior region of the ankle through two portals is becoming more widespread for the treatment of a large number of conditions which used to be treated with open surgery years ago. The tendon of the flexor hallucis longus (FHL) travels along an osteofibrous tunnel between the posterolateral and posteromedial tubercles of the talus. Chronic inflammation of this tendon may lead to painful stenosing tenosynovitis. The aim of this report is to describe two cases depicting an accessory tendon which is an anatomical variation of the flexor hallucis longus in patients with posterior friction syndrome due to posterior ankle impingement and associated with a posteromedial osteochondral lesion of the talus. The anatomical variation (FDAL) described was a finding during an endoscopy of the posterior region of the ankle, and we have spared it by sectioning the superior flexor retinaculum only. The accessory flexor digitorum longus is an anatomical variation and should be taken into account when performing an arthroscopy of the posterior region of the ankle. We recommend this treatment on this type of injury although we admit this does not make a definite conclusion. PMID:26060592

  7. Arthroscopic subtalar arthrodesis: the posterior approach in the prone position.

    PubMed

    Carro, Luis Perez; Golanó, Pau; Vega, Jordi

    2007-04-01

    Arthroscopic subtalar arthrodesis, as reported by Tasto, is done in the lateral decubitus position, and the portal sites are lateral. This report describes a new alternative method in which the patient is in the prone position and a posterior 2-portal approach is used, as described by van Dijk et al. The initial debridement and synovectomy are performed with 4- and 5-mm resectors. Debridement and decortication are done posterior to the interosseous ligament because only the posterior facet is fused. Denudation of the articular surfaces is performed with curettes, as well as 4.5- and 5.5-mm burs, to remove 2 mm of subchondral bone. Stabilization in 5 degrees of hindfoot valgus is accomplished with 2 percutaneous cannulated headless screws from the non-weight-bearing portion of the calcaneal tuberosity directed to a point 5 to 10 mm posterior to the anterior margin of the posterior facet. The advantages of this alternative treatment are better intra-articular visualization, more thorough preparation of the fusion site, and minimal bone removal of the lateral side with better control of the arthrodesis position and with less chance of malunion, as well as the possibility to perform a concomitant surgical fusion or debridement of the ankle joint during the same operative procedure with no need for additional portals or orientation.

  8. Instrumented Posterior Lumbar Interbody Fusion in Adult Spondylolisthesis

    PubMed Central

    Yu, Ching-Hsiao; Wang, Chen-Ti

    2008-01-01

    It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18846411

  9. Biochemical and Clinical Assessments of Segmental Maxillary Posterior Tooth Intrusion

    PubMed Central

    Tasanapanont, Jintana; Wattanachai, Tanapan; Apisariyakul, Janya; Pothacharoen, Peraphan; Kongtawelert, Prachya; Midtbø, Marit

    2017-01-01

    Objective. To compare chondroitin sulphate (CS) levels around maxillary second premolars, first molars, and second molars between the unloaded and the loaded periods and to measure the rates of intrusion of maxillary posterior teeth during segmental posterior tooth intrusion. Materials and Methods. In this prospective clinical study, 105 teeth (from 15 patients exhibiting anterior open bite and requiring maxillary posterior tooth intrusion) were studied. Competitive ELISA was used to detect CS levels. Dental casts (during the unloaded and loaded periods) were scanned, and posterior tooth intrusion distances were measured. Results. During the unloaded period, the median CS levels around maxillary second premolars, first molars, second molars (experimental teeth), and mandibular first molars (negative control) were 0.006, 0.055, 0.056, and 0.012 and during the loaded period were 2.592, 5.738, 4.727, and 0.163 ng/μg of total protein, respectively. The median CS levels around experimental teeth were significantly elevated during the loaded period. The mean rates of maxillary second premolar and first and second molar intrusion were 0.72, 0.58, and 0.40 mm/12 weeks, respectively. Conclusions. Biochemical and clinical assessments suggested that the segmental posterior tooth intrusion treatment modality with 50 g of vertical force per side was sufficient. Trial Registration. The study is registered as TCTR20170206006. PMID:28321256

  10. Interactions between biomaterials and the sclera: Implications on myopia progression

    NASA Astrophysics Data System (ADS)

    Su, James

    Myopia prevalence has steadily climbed worldwide in recent decades with the most dramatic impact in East Asian countries. Treatments such as eyeglasses, contact lenses, and laser surgery for the refractive error are widely available, but none cures the underlying cause. In progressive high myopia, invasive surgical procedures using a scleral buckle for mechanical support are performed since the patient is at risk of becoming blind. The treatment outcome is highly dependent on the surgeon's skills and the patient's myopia progression rate, with limited choices in buckling materials. This dissertation, in four main studies, represents efforts made to control high myopia progression through the exploration and development of biomaterials that influence scleral growth. First, mRNA expression levels of the chick scleral matrix metalloproteinases, tissue-inhibitor of matrix metalloproteinases, and transforming growth factor-beta 2 were assessed for temporal and defocus power effects. The first study elucidated the roles that these factors play in scleral growth regulation and suggested potential motifs that can be incorporated in future biomaterials design. Second, poly(vinyl-pyrrolidone) as injectable gels and poly(2-hydroxyethyl methacrylate) as solid strips were implanted in chicks to demonstrate the concept of posterior pole scleral reinforcements. This second study found that placing appropriate biomaterials at the posterior pole of the eye could directly influence scleral remodeling by interacting with the host cells. Both studies advanced the idea that scleral tissue remodeling could be potentially controlled by well-designed biomaterials. These findings led to the exploration of biomimetic hydrogels comprising enzymatically-degradable semi-interpenetrating polymer networks (edsIPNs) to determine their biocompatibility and effects on the chick posterior eye wall. This third study demonstrated the feasibility of stimulating scleral growth by applying biomimetic

  11. Ultrasound elasticity imaging of human posterior tibial tendon

    NASA Astrophysics Data System (ADS)

    Gao, Liang

    Posterior tibial tendon dysfunction (PTTD) is a common degenerative condition leading to a severe impairment of gait. There is currently no effective method to determine whether a patient with advanced PTTD would benefit from several months of bracing and physical therapy or ultimately require surgery. Tendon degeneration is closely associated with irreversible degradation of its collagen structure, leading to changes to its mechanical properties. If these properties could be monitored in vivo, it could be used to quantify the severity of tendonosis and help determine the appropriate treatment. Ultrasound elasticity imaging (UEI) is a real-time, noninvasive technique to objectively measure mechanical properties in soft tissue. It consists of acquiring a sequence of ultrasound frames and applying speckle tracking to estimate displacement and strain at each pixel. The goals of my dissertation were to 1) use acoustic simulations to investigate the performance of UEI during tendon deformation with different geometries; 2) develop and validate UEI as a potentially noninvasive technique for quantifying tendon mechanical properties in human cadaver experiments; 3) design a platform for UEI to measure mechanical properties of the PTT in vivo and determine whether there are detectable and quantifiable differences between healthy and diseased tendons. First, ultrasound simulations of tendon deformation were performed using an acoustic modeling program. The effects of different tendon geometries (cylinder and curved cylinder) on the performance of UEI were investigated. Modeling results indicated that UEI accurately estimated the strain in the cylinder geometry, but underestimated in the curved cylinder. The simulation also predicted that the out-of-the-plane motion of the PTT would cause a non-uniform strain pattern within incompressible homogeneous isotropic material. However, to average within a small region of interest determined by principal component analysis (PCA

  12. Subjective experience, involuntary movement, and posterior alien hand syndrome

    PubMed Central

    Bundick, T; Spinella, M

    2000-01-01

    The alien hand syndrome, as originally defined, was used to describe cases involving anterior corpus callosal lesions producing involuntary movement and a concomitant inability to distinguish the affected hand from an examiner's hand when these were placed in the patient's unaffected hand. In recent years, acceptable usage of the term has broadened considerably, and has been defined as involuntary movement occurring in the context of feelings of estrangement from or personification of the affected limb or its movements. Three varieties of alien hand syndrome have been reported, involving lesions of the corpus callosum alone, the corpus callosum plus dominant medial frontal cortex, and posterior cortical/subcortical areas. A patient with posterior alien hand syndrome of vascular aetiology is reported and the findings are discussed in the light of a conceptualisation of posterior alien hand syndrome as a disorder which may be less associated with specific focal neuropathology than are its callosal and callosal-frontal counterparts.

 PMID:10601408

  13. Local estimation of posterior class probabilities to minimize classification errors.

    PubMed

    Guerrero-Curieses, Alicia; Cid-Sueiro, Jesús; Alaiz-Rodríguez, Rocío; Figueiras-Vidal, Aníbal R

    2004-03-01

    Decision theory shows that the optimal decision is a function of the posterior class probabilities. More specifically, in binary classification, the optimal decision is based on the comparison of the posterior probabilities with some threshold. Therefore, the most accurate estimates of the posterior probabilities are required near these decision thresholds. This paper discusses the design of objective functions that provide more accurate estimates of the probability values, taking into account the characteristics of each decision problem. We propose learning algorithms based on the stochastic gradient minimization of these loss functions. We show that the performance of the classifier is improved when these algorithms behave like sample selectors: samples near the decision boundary are the most relevant during learning.

  14. ‘Split posterior tooth’: conservative clinical re-attachment

    PubMed Central

    Abraham, Sathish; Chacko, Lisa Neelathil

    2014-01-01

    Trauma is the prime causative factor for fracture of teeth/dentition. Many procedural management options are followed successfully in relation to the anterior teeth. However, most posterior cases where the tooth is fractured have only limited options to pursue to save the tooth. Fractured teeth, whether they are vital/non-vital, are predominantly managed with surgical options. This paper discusses a conservative approach to reattaching a split posterior tooth. A split tooth situation is mostly an absolute indication for extraction, but the clinician may go in for extensive surgical procedures if he/she wishes to save it. The reattachment of the tooth can be successfully done and it can be put to function. This paper discusses how a split posterior tooth can be treated successfully, although depending on multiple factors. A full crown cemented after successful reattachment and root canal therapy would provide sufficient support in order for the tooth to heal. PMID:25080545

  15. Endothelin: A novel peptide in the posterior pituitary system

    SciTech Connect

    Yoshizawa, Toshihiro; Kanazawa, Ichiro; Shinmi, Osamu; Kimura, Sadao; Yanagisawa, Masashi; Masaki, Tomoh; Uchiyama, Yasuo ); Giaid, A.; Gibson, S.J.; Polak, J.M. )

    1990-01-26

    Endothelin (ET), originally characterized as a 21-residue vasoconstrictor peptide from endothelial cells, is present in the porcine spinal cord and may act as a neuropeptide. Endothelin-like immunoreactivity has now been demonstrated by immunohistochemistry in the paraventricular and supraoptic nuclear neurons and their terminals in the posterior pituitary of the pig and the rat. The presence of ET in the porcine hypothalamus was confirmed by reversed-phase high-pressure liquid chromatography and radioimmunoassay. Moreover, in situ hybridization demonstrated ET messenger RNA in porcine paraventricular nuclear neurons. Endothelin-like immunoreactive products in the posterior pituitary of the rat were depleted by water deprivation, suggesting a release of ET under physiological conditions. These findings indicate that ET is synthesized in the posterior pituitary system and may be involved in neurosecretory functions.

  16. Ligamentous and capsular restraints to experimental posterior elbow joint dislocation.

    PubMed

    Deutch, Søren R; Olsen, Bo S; Jensen, Steen L; Tyrdal, Stein; Sneppen, Otto

    2003-10-01

    Pathological external forearm rotation (PEFR) relates to posterolateral elbow joint instability, and is considered a possible requisite step in a simple posterior elbow joint dislocation. The aim of this study was to evaluate the capsuloligamentous restraint to PEFR. In all, 18 elbow joint specimens were examined in a joint analysis system developed for experimental elbow dislocation. Sequential cutting of capsule and ligaments followed by stability testing provided specific data relating to each capsuloligamentous structure. The primary stabilizers against PEFR in the extended elbow were the anterior capsule and the lateral collateral ligament complex (LCLC), whereas in the flexed elbow the anterior capsule did not have a stabilizing effect. In flexed joint positions, the LCLC seems to be the only immediate stabilizer against PEFR, and thereby against posterolateral instability and possibly against posterior dislocation. The medial collateral ligament did not have any immediate stabilizing effect, but it prevented the final step of the posterior dislocation.

  17. Ossification of the posterior atlantoaxial membrane associated with atlas hypoplasia

    PubMed Central

    Meng, Yichen; Zhou, Dongxiao; Gao, Rui; Ma, Jun; Wang, Ce; Zhou, Xuhui

    2016-01-01

    Abstract Rationale: Hypoplasia with an intact posterior arch of the atlas and ossification of the posterior atlantoaxial membrane (PAAM) are individually rare. Patient concerns: The patient presented with a 6-month history of progressive weakness and paresthesia of his lower extremities. Diagnoses: Cervical myelopathy resulting from atlas hypoplasia and ossification of the posterior atlantoaxial membrane. Interventions: Laminectomy of the atlas with duroplasty. Outcomes: Preoperative symptoms were alleviated. Lessons: In most reported cases, either atlas hypoplasia or ossification of the PAAM is responsible for patients’ myelopathy. The case illustrated here, to the best of our knowledge, is the first one with coexistent atlas hypoplasia and ossification of the PAAM. And laminectomy of the atlas with duroplasty provided satisfied outcome. PMID:27902623

  18. Language Disorders due to Posterior System Strokes - An Ignored Dysfunction

    PubMed Central

    ÖZTÜRK, Şerefnur; EGE, Fahrettin; EKMEKÇİ, Hakan

    2014-01-01

    The anterior system is primarily responsible for the clinical picture in a patient that presents with clinical aphasia. However, recent reports have shown that injuries to posterior structures, the cerebellum in particular, may have a role in language processing. Herein, we will look first at the linguistic role of the cerebellum in light of the literature, then of the thalamus and some described clinical syndromes, and finally, specific syndromes resulting from occipital lobe lesions, all of which are supported by the posterior vascular system. The human brain is such a complex organization that in addition to the thalamus and occipital cortex, we can see the involvement of the cerebellum in high cognitive functions. Posterior system strokes may lead to clinical findings of cognitive deficits, including neurolinguistic components. Determining these defects in stroke patients may precipitate changes in current management strategies. PMID:28360648

  19. [Segmental posterior spinal osteosynthesis using the Luque-Dove technic].

    PubMed

    Kerboul, B; Courtois, B

    1989-03-01

    The Hartshill frame is method for segmental osteosynthesis of the spine. It is attached at each vertebral level by sub-laminal metal wires. This frame therefore ensures immediate stability and avoids the need for a post-operative corset. It enables correction of frontal deformities (scoliosis) whilst retaining sagittal physiological curves (lumbar lordosis--dorsal kyphosis). It ensures the fixation of posterior spinal instability (destruction of posterior ligaments and bone tissue, spondylolisthesis, etc.). The Hartshill frame can thus be seen to be a posterior brace. It has been used in 92 patients, (53 lumbar disorders, 10 cases of scoliosis, 4 of kyphosis, 19 tumors, 6 fractures). Results are generally entirely satisfactory in the mid term apart from fractures (recurrence of initial displacement). Specific complications are of a neurological nature (cases of cutaneous hyperesthesia, one severe motor deficit) long-term problems with device and material are uncommon; rupture of sub-laminar wire 8 cases; secondary incurving of frame 1 case.

  20. Ganglion cyst of the posterior cruciate ligament in a child.

    PubMed

    Hameed, Shamsi Abdul; Sujir, Premjit; Naik, Monappa A; Rao, Sharath K

    2012-04-01

    Ganglion cysts are more commonly associated with the anterior cruciate ligament than the posterior cruciate ligament (PCL). A literature review showed that all reported cases of ganglion cysts to date involved adults. We report a rare case of ganglion cyst in the PCL of a four-year-old boy, and discuss its aetiology, clinical presentation, imaging features and management. Ganglion cysts of the PCL may be confused with meniscal cysts arising from tears of the posterior horn of the medial meniscus on magnetic resonance (MR) imaging. Hence, the posterior horn of the medial meniscus has to be carefully evaluated to rule out a tear. MR imaging is the method of choice to confirm diagnosis, and arthroscopic resection is a safe treatment modality even in children.

  1. Posterior Wall Gastric Leiomyoma: Endoscopic Tattooing Facilitates Laparoscopic Resection

    PubMed Central

    Mehta, Dhiren; Zelen, Johnathan; Fogler, Richard

    1998-01-01

    Objective: To demonstrate the application of tattooing for the intraoperative localization of posterior wall gastric leiomyoma during laparoscopic resection. The preoperative injection of Indian ink in the tumor-bearing area of the posterior gastric wall eliminates the need to perform anterior wall gastrostomy or intraoperative upper endoscopic tumor localization. Methods: A patient with posterior wall gastric leiomyoma was marked with Indian ink during preoperative upper endoscopy. The dye was visualized intraoperatively facilitating wedge resection of the tumor-bearing area with the Endo GIA. Results: The patient had an uneventful surgery and recovery. Complete excision of the tumor was accomplished. Conclusion: The preoperative endoscopic marking of gastric lesions, facilitates the intraoperative localization and resection of these lesions. PMID:9876718

  2. Structural Position of the Posterior Vagina and Pelvic Floor in Women with and without Posterior Vaginal Prolapse

    PubMed Central

    LEWICKY-GAUPP, Christina; YOUSUF, Aisha; LARSON, Kindra A; FENNER, Dee E; DeLANCEY, John OL

    2012-01-01

    Objective Compare pelvic structure location on MRI during maximal Valsalva among women with posterior prolapse and those with normal support. Methods and Materials Cases (n=37) had posterior vaginal wall (PVW) prolapse > +1cm. All underwent mid-sagittal, dynamic MRI. Structure locations (distal vagina, apex, perineal body, external anal sphincter) were determined. PVW length, levator and urogenital hiatus diameters, and prolapse diameter were measured. Results Cases had more caudal structures (p<0.001) and larger hiatus diameters (p<0.005); the posterior wall was longer, while the straight-line distance between the apex and distal vagina was shorter. In enteroceles, the apex was more ventrally displaced compared to rectoceles (p=0.003). Unlike apical descent (r=-0.3, p=0.1), PVW length and point Bp were correlated with MRI prolapse size (r=0.5, p=0.002; r=0.7, P<0.001, respectively). Conclusion At maximal Valsalva on MRI, structures are more caudal in women with posterior prolapse. The posterior vaginal wall is longer; this length strongly correlates with prolapse size. PMID:20452497

  3. Posterior clinoidectomy: dural tailoring technique and clinical application.

    PubMed

    Youssef, A Samy; van Loveren, Harry R

    2009-05-01

    The posterior clinoid process, a bony prominence at the superolateral aspect of the dorsum sellae, has a strategic importance in a transcavernous approach to basilar tip aneurysms. To further optimize this microsurgical technique during posterior clinoidectomy, we performed a cadaveric study of this regional anatomy, describe a technique called dural tailoring, and report initial results in the surgical treatment of upper basilar artery (BA) aneurysm. After 10 adult cadaver heads (silicone-injected) were prepared for dissection, a posterior clinoidectomy with dural tailoring was performed. The dura overlying the upper clivus was coagulated with bipolar electrocoagulation and incised. Stripping dura off the clivus and lateral reflection then exposed the ipsilateral posterior clinoid process and dorsum sellae, thus creating a dural flap. Posterior clinoidectomy with dural tailoring was then used in seven patients with upper BA aneurysms. Our stepwise modification of the posterior clinoidectomy with dural tailoring created a flap that afforded protection of the cavernous sinus and oculomotor nerve. During surgery, there were no recorded intraoperative injuries to neurovascular structures. One patient died postoperatively from morbidity related to severe-grade subarachnoid hemorrhage. Postoperative oculomotor nerve palsy occurred in 3 patients (43%). In all cases, the nerve was anatomically preserved and partial to complete recovery was recorded during the first postoperative year. This technique effectively provided exposure of retrosellar upper basilar aneurysms in seven patients (basilar tip 43% and superior cerebellar artery aneurysms 57%). Outcomes and safety are at least equivalent to or better than basilar aneurysm surgery performed without surgical adjuncts, presumably a less complex subset.

  4. Teaching of posterior composites in dental schools in Japan.

    PubMed

    Hayashi, M; Seow, L L; Lynch, C D; Wilson, N H F

    2009-04-01

    The teaching of posterior composites has undergone considerable refinement and development in western countries in recent years. However, little information exists on this teaching in other parts of the world. The aim of this paper is to investigate the teaching of posterior composites to undergraduate dental students in Japan. In late 2007/early 2008, a questionnaire seeking information on the teaching of posterior composites was distributed by email to the person responsible for teaching operative dentistry in each of the 29 dental schools having undergraduate dental degree programmes in Japan. Twenty-three completed responses were returned (response rate = 79%). While all 23 schools taught the placement of composite in occlusal cavities in premolars and molars, 7 schools did not teach the placement of two-surface occlusoproximal composites in premolars (n = 1) and molars (n = 6) and 14 schools and 15 schools do not teach placement of three surface occlusoproximal composites in premolars and molars, respectively. While composite at the time of the survey accounted for 45% of posterior direct restorations placed by students, it is anticipated that this proportion will increase to 59% in 5 years time. Variations were noted between schools in the teaching of principles of cavity design, techniques for restoring proximal contours and light-curing technologies; however, more consistency was observed in techniques used for protecting operatively exposed dentine than that observed in western countries. Despite variations between dental schools being noted in the teaching of certain techniques for posterior composites, the overall extent and content of teaching of posterior composites in Japan could be described as comparable, if not exceeding, than that observed in western countries.

  5. [Postoperative opacification of posterior chamber intraocular lenses - a review].

    PubMed

    Schmidbauer, J M; Werner, L; Apple, D J; Pandey, S K; Izak, A M; Trivedi, R H; Macky, T A; Auffarth, G U; Peng, Q; Arthur, S N; Escobar-Gomez, M; Ma, L; Vargas, L G

    2001-09-01

    Postoperative opacification of intraocular lenses (IOLs) is a very unpleasant complication for the ophthalmic surgeon and the patient. We report on our experiences with opacification of different foldable IOL designs and rigid poly (methyl methacrylate) (PMMA) posterior chamber lenses.1. Snowflake degeneration of PMMA IOLs: This condition is an unanticipated and surprising late postoperative finding 8 to 15 years after implantation. In our opinion, this complication is probably not related to the PMMA biomaterial itself, but rather it appears to represent a manufacturing problem that has affected a selected, albeit large number of lenses manufactured in the 1980s-mid 1990s.2. Degeneration of UV absorber material and calcium deposits within the optic of hydrophilic IOLs: Two years postoperatively degenerations of UV absorber material and calcium deposits within the optic of single piece hydrophilic acrylic lenses SC60B-OUV manufactured by MDR (Medical developmental research Inc. Clearwater FL, USA) can occur. Although the precise mechanism is not fully known, it was assumed that these opacifications are due to premature aging of the UV blocking agent incorporated in the lens biomaterial and calcification.3. Calcification on the surface of the Bausch & Lomb Hydroviewtrade mark IOLs: Twelve to 15 months postoperatively granular surface calcifications in Hydroviewtrade mark IOLs occured. The mechanism is not fully understood. According to Bausch and Lomb studies, part of the components of the packaging contained silicone, which may have come off the packaging onto the lens optic, where it then appears to be a catalyst for calcium precipitation. The manufacturer has correlated a change in packaging with the appearance of the opacification. The manufacturer now believes that this problem has been solved. However, final verification will require a careful 1 - 2 years clinical study.4. Glistenings in the hydrophobic acrylic AcrySoftrade mark IOLs: The time frame of

  6. Optic nerve fast axonal transport abnormalities in primates. Occurrence after short posterior ciliary artery occlusion.

    PubMed

    Radius, R L

    1980-11-01

    Fast axonal transport abnormalities in primate (Aotus trivirgatus) optic nerve were studied in ten eyes at various intervals after occlusion of the lateral short posterior ciliary circulation. Evidence of focal axonal ischemia, as indicated by swelling of mitochondria and dissolution of cytoplasmic detail, was noted as early as one hour after occlusion. Accumulation of mitochondria, microvesicles, and dense bodies, indicating focal interruption of axonal transport mechanisms, was noted in eyes examined at 2, 4, and 6 hours. This accumulation of organelles was limited to the region of the lamina cribrosa. Nerve head abnormalities were not seen in two eyes studied at two weeks.

  7. Respiratory arrest following posteriorly displaced odontoid fractures. Case reports and review of the literature.

    PubMed

    Lewallen, R P; Morrey, B F; Cabanela, M E

    1984-09-01

    Posterior displacement of the odontoid after fracture occurs much less frequently than does anterior displacement. Experience with four patients suggests that anatomic reduction may not be possible and prolonged attempts to gain reduction are not advisable. Those cases should be managed with early application of a halo vest. A rotating frame should be avoided. The potential for respiratory arrest, at least in the older individual, is great and can be precipitated even by a change of position in the process of turning on the rotating frame. The mechanism of the respiratory failure is obscure.

  8. Posterior tibial vein aneurysm presenting as tarsal tunnel syndrome.

    PubMed

    Ayad, Micheal; Whisenhunt, Anumeha; Hong, EnYaw; Heller, Josh; Salvatore, Dawn; Abai, Babak; DiMuzio, Paul J

    2015-06-01

    Tarsal tunnel syndrome is a compressive neuropathy of the posterior tibial nerve within the tarsal tunnel. Its etiology varies, including space occupying lesions, trauma, inflammation, anatomic deformity, iatrogenic injury, and idiopathic and systemic causes. Herein, we describe a 46-year-old man who presented with left foot pain. Work up revealed a venous aneurysm impinging on the posterior tibial nerve. Following resection of the aneurysm and lysis of the nerve, his symptoms were alleviated. Review of the literature reveals an association between venous disease and tarsal tunnel syndrome; however, this report represents the first case of venous aneurysm causing symptomatic compression of the nerve.

  9. Posture and posterior crossbite in oral and nasal breathing children.

    PubMed

    Costa, Jecilene Rosana; Pereira, Silvia Regina Amorim; Pignatari, Shirley S N; Weckx, Luc Louis Maurice

    2010-01-01

    The most known etiologic factors of oral breathing may influence the craniofacial development leading to anatomical and functional alterations. A proper head and cervical spine posture allows a well functioning of the stomatognathic system structures and vice versa. This study was conducted to evaluate the prevalence of posterior crossbite in a group of oral breathing children (OB) and nasal (NB) and associate the type of bite with the head and cervical spine posture. It was concluded that most of the children, either oral or nasal breathers, did not present a crossbite and any kind of head posture and cervical spine can vary independently of a posterior crossbite.

  10. Posterior dislocation of the sternoclavicular joint: report of two cases.

    PubMed

    Labronici, Pedro José; Souza, Fabrício Cardoso de; Pires, Robinson Esteves Santos; Santos Filho, Fernando Claudino Dos; Gameiro, Vinicius Schott; Labronici, Gustavo José

    2016-01-01

    The authors report the cases of two young patients who had suffered a sporting accident with posterior traumatic dislocation of sternoclavicular joint. In one of the patients closed reduction was accomplished by keeping the limb in a sling. The second patient, after reduction was done, presented recurrence of the dislocation, thus requiring surgical treatment. It is important to observe the relevance of computed tomography to help diagnosing, as well as monitoring the reduction procedure. The objective of this study was to demonstrate two different types of treatment in a rare injury such as the posterior dislocation of sternoclavicular joint.

  11. Management of Posterior Reversible Syndrome in Preeclamptic Women

    PubMed Central

    Poma, S.; Delmonte, M. P.; Gigliuto, C.; Imberti, R.; Delmonte, M.; Arossa, A.; Iotti, G. A.

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological syndrome associated with a number of conditions including preeclampsia. It is characterized by seizures, alteration of consciousness, visual disturbances, and symmetric white matter abnormalities, typically in the posterior parietooccipital regions of the cerebral hemispheres, at computed tomography (CT) and magnetic resonance (MRI). We report three new cases of PRES in preeclamptic patients and describe the management of these patients. We present a brief review of other cases in the literature, with particular attention to the anesthetic management. PMID:25506009

  12. Spectral domain optical coherence tomography finding in posterior microphthalmos.

    PubMed

    Kumar, Mukesh; Das, Taraprasad; Kesarwani, Siddharth

    2012-11-01

    An eight-year-old boy presented with decreased vision in both eyes. At presentation, the visual acuity was 6/60 in both eyes with high plus spheres. Anterior segment examination was normal. Fundus examination and spectral domain optical coherence tomography were consistent with posterior microphthalmos and showed an elevated foveal contour and fold in the outer plexiform layer. External limiting membrane, photoreceptor and retinal pigment epithelium were not involved in the fold. To the best of our knowledge this is the first such case report with optical coherence tomography imaging of the retinal layer involved in a case of posterior microphthalmos.

  13. Recanalization of an occluded popliteal artery following posterior knee dislocation.

    PubMed

    Kirby, L; Abbas, J; Brophy, C

    1999-11-01

    Posterior knee dislocation results in popliteal artery injury in up to one-third of cases. Prompt recognition and treatment of arterial injury is essential for limb salvage. We report a case of complete occlusion of the popliteal artery following posterior knee dislocation treated with saphenous vein bypass without exclusion of the injured arterial segment. Follow-up duplex scanning demonstrated a patent vein graft and a patent ipsilateral popliteal artery. This report suggests that, in some instances, a traumatically occluded popliteal artery may recanalize, and that revascularization with a bypass graft may be the preferred method of repair, particularly in young patients.

  14. Bilateral epididymitis in a child with undiagnosed posterior urethral valves.

    PubMed

    Kwong, Justin; Lorenzo, Armando J; DeMaria, Jorge; Braga, Luis H P

    2013-07-01

    Posterior urethral valves are most commonly detected in the early neonatal period, the diagnosis often antenatally suspected from ultrasound findings. Nevertheless, some cases might go undetected and become manifest later in life with lower urinary tract symptoms. We describe the unusual case of a 5-year-old boy with a 2-month history of bladder distension, urinary dribbling, and epididymitis. Cystourethrography revealed posterior urethral valves with reflux into the seminal vesicles, vas deferens, and epididymis, bilaterally. A review of the published data is provided in the context of this unusual presentation pattern.

  15. Double triangular resection for a widely prolapsed posterior mitral leaflet†

    PubMed Central

    Sawazaki, Masaru; Tomari, Shiro; Tsunekawa, Tomohiro; Izawa, Naoto

    2013-01-01

    A wide and redundant prolapse of the posterior mitral leaflet in active infective endocarditis cannot be easily repaired. A sliding plasty can be attempted, but the range of annular plication is often too large. Chordal replacement is another option, but is prone to long-term degeneration because the redundant leaflet still exists. Here, we describe a simple resection technique that utilizes only two small triangular resections. The resections are sutured with no need to shorten the annulus. The leaflet tissue between the two triangular resections must be preserved to make an appropriately shaped posterior leaflet. PMID:23223672

  16. Recurrent Massive Epistaxis from an Anomalous Posterior Ethmoid Artery

    PubMed Central

    Mattioli, Francesco; Alberici, Maria Paola; Presutti, Livio

    2016-01-01

    A 50-year-old man, with no previous history of epistaxis, was hospitalized at our facility for left recurrent posterior epistaxis. The patient underwent surgical treatment three times and only the operator's experience and radiological support (cranial angiography) allowed us to control the epistaxis and stop the bleeding. The difficult bleeding management and control was attributed to an abnormal course of the left posterior ethmoidal artery. When bleeding seems to come from the roof of the nasal cavity, it is important to identify the ethmoid arteries always bearing in mind the possible existence of anomalous courses. PMID:28025632

  17. Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

    PubMed Central

    Kim, Hong-Ki; Kim, Ki-Jeong; Jahng, Tae-Ahn; Kim, Hyun-Jib

    2016-01-01

    Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation. PMID:27114779

  18. 3D Shape Perception in Posterior Cortical Atrophy: A Visual Neuroscience Perspective

    PubMed Central

    Gillebert, Céline R.; Schaeverbeke, Jolien; Bastin, Christine; Neyens, Veerle; Bruffaerts, Rose; De Weer, An-Sofie; Seghers, Alexandra; Sunaert, Stefan; Van Laere, Koen; Versijpt, Jan; Vandenbulcke, Mathieu; Salmon, Eric; Todd, James T.; Orban, Guy A.

    2015-01-01

    Posterior cortical atrophy (PCA) is a rare focal neurodegenerative syndrome characterized by progressive visuoperceptual and visuospatial deficits, most often due to atypical Alzheimer's disease (AD). We applied insights from basic visual neuroscience to analyze 3D shape perception in humans affected by PCA. Thirteen PCA patients and 30 matched healthy controls participated, together with two patient control groups with diffuse Lewy body dementia (DLBD) and an amnestic-dominant phenotype of AD, respectively. The hierarchical study design consisted of 3D shape processing for 4 cues (shading, motion, texture, and binocular disparity) with corresponding 2D and elementary feature extraction control conditions. PCA and DLBD exhibited severe 3D shape-processing deficits and AD to a lesser degree. In PCA, deficient 3D shape-from-shading was associated with volume loss in the right posterior inferior temporal cortex. This region coincided with a region of functional activation during 3D shape-from-shading in healthy controls. In PCA patients who performed the same fMRI paradigm, response amplitude during 3D shape-from-shading was reduced in this region. Gray matter volume in this region also correlated with 3D shape-from-shading in AD. 3D shape-from-disparity in PCA was associated with volume loss slightly more anteriorly in posterior inferior temporal cortex as well as in ventral premotor cortex. The findings in right posterior inferior temporal cortex and right premotor cortex are consistent with neurophysiologically based models of the functional anatomy of 3D shape processing. However, in DLBD, 3D shape deficits rely on mechanisms distinct from inferior temporal structural integrity. SIGNIFICANCE STATEMENT Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by progressive visuoperceptual dysfunction and most often an atypical presentation of Alzheimer's disease (AD) affecting the ventral and dorsal visual streams rather than the medial

  19. Posterior Predictive Assessment of Item Response Theory Models

    ERIC Educational Resources Information Center

    Sinharay, Sandip; Johnson, Matthew S.; Stern, Hal S.

    2006-01-01

    Model checking in item response theory (IRT) is an underdeveloped area. There is no universally accepted tool for checking IRT models. The posterior predictive model-checking method is a popular Bayesian model-checking tool because it has intuitive appeal, is simple to apply, has a strong theoretical basis, and can provide graphical or numerical…

  20. Missed C1 posterior arch fracture: a case report

    PubMed Central

    Munro, Donald S

    1990-01-01

    A case of a C1 posterior arch fracture following a fall is presented. The need to perform a thorough history and examination, regardless of previous examination findings, is emphasized. This is especially true when there is a history of recent trauma. A brief discussion of the characteristics and management of C1 fractures follows. ImagesFigure 1Figure 2Figure 3

  1. Spontaneous defects between the mastoid and posterior cranial fossa.

    PubMed

    Rereddy, Shruthi K; Mattox, Douglas E

    2016-01-01

    Conclusions Spontaneous defects between the mastoid and the posterior cranial fossa are exceedingly rare. Patients with these lesions may have a lower BMI compared to those with middle cranial fossa encephaloceles, but are otherwise demographically similar. This study recommends repair via a transtemporal approach to allow for examination of the entire posterior face of the temporal bone. Objective To describe cases of spontaneous posterior cranial fossa defects. Methods This study reviewed all cases of spontaneous posterior fossa defects presenting to a tertiary referral center over the last decade and described clinical presentation, imaging, operative findings, and outcomes. We also compared these lesions to those previously reported in the literature as well as the more common spontaneous encephaloceles of the middle cranial fossa. Results This study identified five cases with a mean age of 61.4 years, female-to-male ratio of 4:1, and a mean BMI of 31. Three cases presented with spontaneous pneumocephalus, one with CSF otorrhea, and one as an incidental imaging finding. Four defects were found medial to the sigmoid sinus and one was in the lateral retrosigmoid air cells.

  2. Covering Your Posterior: Teaching Signaling Games Using Classroom Experiments

    ERIC Educational Resources Information Center

    Turocy, Theodore L.

    2009-01-01

    The author describes a protocol for classroom experiments for courses that introduce undergraduates to signaling games. Signaling games are conceptually difficult because, when analyzing the game, students are not naturally inclined to think in probabilistic, Bayesian terms. The experimental design explicitly presents the posterior frequencies of…

  3. Atrial natriuretic factor-like activity in rat posterior pituitary

    SciTech Connect

    Gutkowska, J.; Debinski, W.; Racz, K.; Thibault, G.; Garcia, R.; Kuchel, O.; Genest, J.; Cantin, M.

    1986-03-05

    The presence of a biologically active peptide: Atrial Natriuretic Factor (ANF) has been demonstrated in rat and human circulation and ANF is considered now as a new hormone. ANF may be involved in body fluid regulation. A very sensitive radioimmunoassay for rat ANF allowed the authors to search for immunoreactive ANF (IR-ANF) in rat posterior pituitary. Serial dilutions of homogenates of rat posterior pituitary showed a good parallelism with a reference curve in a radioimmunoassay system. The IR-ANF was extracted from rat posterior pituitary homogenates by activated Vycor glass beads. The lyophilized extract was purified by HPLC on C/sub 18/ ..mu.. Bondapak column. The HPLC yielded two IR-ANF peaks. Both isolated ANF-like material showed biological activity. The IR-ANF eluted with 33% acetonitrile, inhibited ACTH-stimulated aldosterone secretion with a similar potency as synthetic (Arg 101 - Tyr 126) ANF (0.7 x 10/sup -10/M). A much less potent ANF-like material was found in the second peak eluted with 36% acetonitrile. They conclude that ANF-like material is present in rat posterior pituitary and this suggest a possible role in ANF on AVP secretion directly in situ.

  4. Multiclass Posterior Probability Twin SVM for Motor Imagery EEG Classification.

    PubMed

    She, Qingshan; Ma, Yuliang; Meng, Ming; Luo, Zhizeng

    2015-01-01

    Motor imagery electroencephalography is widely used in the brain-computer interface systems. Due to inherent characteristics of electroencephalography signals, accurate and real-time multiclass classification is always challenging. In order to solve this problem, a multiclass posterior probability solution for twin SVM is proposed by the ranking continuous output and pairwise coupling in this paper. First, two-class posterior probability model is constructed to approximate the posterior probability by the ranking continuous output techniques and Platt's estimating method. Secondly, a solution of multiclass probabilistic outputs for twin SVM is provided by combining every pair of class probabilities according to the method of pairwise coupling. Finally, the proposed method is compared with multiclass SVM and twin SVM via voting, and multiclass posterior probability SVM using different coupling approaches. The efficacy on the classification accuracy and time complexity of the proposed method has been demonstrated by both the UCI benchmark datasets and real world EEG data from BCI Competition IV Dataset 2a, respectively.

  5. The posterior meniscofemoral ligament: morphologic study and anatomic classification.

    PubMed

    Han, Seung-Ho; Kim, Deog-Im; Choi, Seung-Gyu; Lee, Jun-Hee; Kim, Yi-Suk

    2012-07-01

    The meniscofemoral ligaments (MFLs) run from the medial femoral condyle to the posterior horn of the lateral meniscus and consist of anterior MFL (aMFL) and/or posterior MFL (pMFL) components according to whether it passes anterior or posterior to the posterior cruciate ligament (PCL). The purpose of this study was to analyze the incidence and morphologic features of the MFLs in Koreans and formulate an anatomic classification system of MFLs to aid the detailed interpretation of medical imaging or biomechanical data. One hundred knees from 52 cadavers were studied. Eighty-seven knees had pMFLs, whereas an aMFL was only found in one knee from a male cadaver. The pMFLs and PCLs were longer in males than in females (P < 0.05). The most common type of MFL was the high crossing of a typical pMFL against the PCL in both genders. Regarding other types, the incidence of absent pMFLs was higher in males than in females and the oblique bundle of the PCL was easily confused with the pMFL in several cases in both genders. These results provide the basis for the classification system of the MFL and will contribute to better outcomes for evaluating the MFL and PCL when using medical imaging such as arthro-CT scan or MRI through a better understanding of the anatomy of the MFL and PCL.

  6. Learning about Posterior Probability: Do Diagrams and Elaborative Interrogation Help?

    ERIC Educational Resources Information Center

    Clinton, Virginia; Alibali, Martha W.; Nathan, Mitchell J.

    2016-01-01

    To learn from a text, students must make meaningful connections among related ideas in that text. This study examined the effectiveness of two methods of improving connections--elaborative interrogation and diagrams--in written lessons about posterior probability. Undergraduate students (N = 198) read a lesson in one of three questioning…

  7. Roseomonas spinal epidural abscess complicating instrumented posterior lumbar interbody fusion.

    PubMed

    Maraki, Sofia; Bantouna, Vasiliki; Lianoudakis, Efstratios; Stavrakakis, Ioannis; Scoulica, Efstathia

    2013-07-01

    The first case of a spinal epidural abscess caused by Roseomonas mucosa following instrumented posterior lumbar fusion is presented. Although rare, because of its highly resistant profile, Roseomonas species should be included in the differential diagnosis of epidural abscesses in both immunocompromised and immunocompetent hosts.

  8. Distinguishing torpedo maculopathy from similar lesions of the posterior segment.

    PubMed

    Villegas, Victor M; Schwartz, Stephen G; Flynn, Harry W; Capó, Hilda; Berrocal, Audina M; Murray, Timothy G; Harbour, J William

    2014-01-01

    Torpedo maculopathy is a congenital solitary, oval-shaped lesion typically located temporal to the center of the macula. Congenital hypertrophy of the retinal pigment epithelium (RPE), RPE lesions of Gardner syndrome, and other lesions can present with similar characteristics. Because of its unique clinical and imaging features, torpedo maculopathy generally can be differentiated from other posterior segment lesions.

  9. Posterior Predictive Model Checking for Multidimensionality in Item Response Theory

    ERIC Educational Resources Information Center

    Levy, Roy; Mislevy, Robert J.; Sinharay, Sandip

    2009-01-01

    If data exhibit multidimensionality, key conditional independence assumptions of unidimensional models do not hold. The current work pursues posterior predictive model checking, a flexible family of model-checking procedures, as a tool for criticizing models due to unaccounted for dimensions in the context of item response theory. Factors…

  10. FEMORAL INSERTION OF THE POSTERIOR CRUCIATE LIGAMENT: AN ANATOMICAL STUDY

    PubMed Central

    de Paula Leite Cury, Ricardo; Severino, Nilson Roberto; Camargo, Osmar Pedro Arbix; Aihara, Tatsuo; Neto, Leopoldo Viana Batista; Goarayeb, Dedley Nelson

    2015-01-01

    Objective: To identify objective parameters to guide correct location of the posterior cruciate ligament (PCL) in the femur. Methods: The PCLs of 20 human cadavers were resected. The following portions were measured: distance from the most distal portion of the PCL, close to the roof, to the most anterior edge of the cartilage (AB); distance from the most proximal portion of the PCL, close to the roof, to the most anterior cartilage (AC); distance between the two parts of the ligament close to the roof (BC); distance from the distal edge in its posterior portion, to the more posterior joint edge (DE); distance from the distal edge of the ligament in its posterior portion, to the intercondylar roof (DF); and finally, the format of the ligament insertion and area of coverage on the femoral condyle. Results: The PCL has the shape of a quarter ellipse, with an average area of 153.5mm2. The mean distances found were: AB of 2.1mm, AC of 10.7mm, BC of 8.6mm DE of 12.4mm and DF of 16.8mm. Conclusions: The edge close to the roof of the anterolateral bundle is closer to the joint cartilage (2.1mm) than the posteromedial bundle is, which is 12.4mm from the edge proximal to the cartilage. These references should assist in better and more accurate positioning of femoral tunnels in PCL reconstruction. PMID:27027059

  11. Trypan blue-assisted posterior capsulorhexis in pediatric cataract surgery

    PubMed Central

    Lotfy, Ayman; Abdelrahman, Ayman

    2017-01-01

    Purpose To evaluate the safety and efficacy of staining the posterior capsule with trypan blue during capsulorhexis in pediatric cataract surgery. Patients and methods This was a prospective randomized comparative study carried out at Alpha Vision Center, Zagazig, Egypt. This study included 2 groups of children with pediatric cataract randomly allocated to undergo irrigation and aspiration. In the trypan group, which included 11 eyes, trypan blue was used to stain the posterior capsule during posterior capsulorhexis. In the control group, which included 10 eyes, no staining was performed. All surgeries were performed by the same surgeon. The 2 groups were compared for criteria such as completion of capsulorhexis, disruption of vitreous face and in-the-bag intraocular lens implantation. Results This study included 21 eyes of 16 patients (age range: 6 months–4 years). A statistically significant difference was observed for the following parameters between the 2 groups: capsulorhexis completion (P=0.04), vitreous face disruption (P=0.01) and in-the-bag intraocular lens implantation (P=0.022). Conclusion This study suggests that staining of the posterior capsule during capsulorhexis in pediatric cataract operation gives better results than capsulorhexis without staining. The stain changes the capsule texture making capsulorhexis easier with fewer complications. PMID:28182152

  12. Tibialis posterior tendon rupture: a cause of rheumatoid flat foot.

    PubMed

    Downey, D J; Simkin, P A; Mack, L A; Richardson, M L; Kilcoyne, R F; Hansen, S T

    1988-03-01

    Flat foot, a major cause of foot pain and disability, may result from rupture of the tibialis posterior tendon. We describe 2 patients with rheumatoid arthritis who developed flat feet secondary to surgically confirmed tendon rupture, and we discuss the anatomy and diagnosis of this condition. In the second patient, we also present the results of tendon imaging with both magnetic resonance and ultrasound.

  13. Accuracy of Posterior Subtalar Joint Injection Without Fluoroscopy

    PubMed Central

    Kirk, Kevin L.; Campbell, John T.; Guyton, Gregory P.

    2008-01-01

    Injection into the posterior subtalar joint has not been validated for accuracy using radiographic end points. We asked whether needle placement into a normal posterior subtalar joint could be performed accurately and selectively by experienced surgeons without fluoroscopic guidance. Three fellowship-trained orthopaedic foot and ankle surgeons each injected the posterior subtalar joint of 20 cadaveric specimens using an anterolateral approach. Fluoroscopic images were obtained by an independent investigator and blinded. A separate fellowship-trained foot and ankle surgeon interpreted the images. Of 60 injections, 58 were accurate and two were extraarticular based on interpretation by an independent foot and ankle surgeon. Extravasation into the ankle occurred in 14 samples and into the peroneal sheath in two samples. Experienced surgeons can place intraarticular injections into a radiographically normal posterior subtalar joint without fluoroscopy with a high degree of accuracy. However, extravasation into the ankle or peroneal tendon sheath occurred in an unpredictable fashion, suggesting selectivity of injection placement is relatively limited without the use of fluoroscopy. Fluoroscopy may not be necessary for injections used solely for therapeutic purposes. However, if the injection is intended for diagnostic purposes or to assist in surgical decision-making or if the joint is abnormal, we recommend fluoroscopy to ensure the subtalar joint is the only anatomic structure impacted by the injection. PMID:18404293

  14. Posterior crossbite and temporomandibular disorders (TMDs): need for orthodontic treatment?

    PubMed

    Thilander, Birgit; Bjerklin, Krister

    2012-12-01

    The aim of this work was to update the bibliography regarding the concept of 'temporomandibular disorder (TMD)' and 'posterior crossbite' and try to find out if there is any association between some special signs/symptoms of TMD and type of posterior crossbite. A literature search from 1970 to 2009, due to specified criterion, resulted in 14 publications that were found to be relevant for the present systematic review. An association between TMD and posterior crossbite (Yes-group) was reported as often as absence of such a relationship (No-group). The samples in the two groups showed similarities as well as differences with respect to number, gender, and age. Most articles reported only on 'presence' or 'absence' of crossbite and only few on type of crossbite opposite to a thorough account of clinical signs and symptoms of TMD. This review seems, however, to state that a functional posterior crossbite (mandibular guidance with midline deviation) is associated with headache, temporomandibular joint and muscular pain, and clicking. As evident from the discussion, such type needs orthodontic treatment to rehabilitate the asymmetric muscular activity between the crossbite and non-crossbite sides and the changed condyle/temporal relationship caused by mandibular deviation. Whether this treatment also will avoid future TMD problems can be answered only after clinical follow-up studies have been performed.

  15. Morphofunctional Compensation of Masseter Muscles in Unilateral Posterior Crossbite Patients

    PubMed Central

    Cutroneo, G.; Vermiglio, G.; Centofanti, A.; Rizzo, G.; Runci, M.; Favaloro, A.; Piancino, M.G.; Bracco, P.; Ramieri, G.; Bianchi, F.; Speciale, F.; Arco, A.; Trimarchi, F.

    2016-01-01

    Unilateral posterior crossbite is a widespread, asymmetric malocclusion characterized by an inverse relationship of the upper and lower buccal dental cusps, in the molar and premolar regions, on one side only of the dental arch. Patients with unilateral posterior crossbite exhibit an altered chewing cycles and the crossbite side masseter results to be less active with respect to the contralateral one. Few studies about morphological features of masticatory muscle in malocclusion disorders exist and most of these have been performed on animal models. The aim of the present study was to evaluate morphological and protein expression characteristics of masseter muscles in patients affected by unilateral posterior crossbite, by histological and immunofluorescence techniques. We have used antibody against PAX-7, marker of satellite cells, and against α-, β-, γ-, δ-, ε- and ζ-sarcoglycans which are transmembrane glycoproteins involved in sarcolemma stabilization. By statistical analysis we have evaluated differences in amount of myonucley between contralateral and ipsilateral side. Results have shown: i) altered fibers morphology and atrophy of ipsilateral muscle if compared to the contralateral one; ii) higher number of myonuclei and PAX-7 positive cells in contralateral side than ipsilateral one; iii) higher pattern of fluorescence for all tested sarcoglycans in contralateral side than ipsilateral one. Results show that in unilateral posterior crossbite hypertrophic response of contralateral masseter and atrophic events in ipsilateral masseter take place; by that, in unilateral posterior crossbite malocclusion masticatory muscles modify their morphology depending on the function. That could be relevant in understanding and healing of malocclusion disorders; in fact, the altered balance about structure and function between ipsilateral and contralateral muscles could, long-term, lead and/ or worsen skeletal asymmetries. PMID:27349311

  16. Posterior Eye Shape Measurement With Retinal OCT Compared to MRI

    PubMed Central

    Kuo, Anthony N.; Verkicharla, Pavan K.; McNabb, Ryan P.; Cheung, Carol Y.; Hilal, Saima; Farsiu, Sina; Chen, Christopher; Wong, Tien Y.; Ikram, M. Kamran; Cheng, Ching Y.; Young, Terri L.; Saw, Seang M.; Izatt, Joseph A.

    2016-01-01

    Purpose Posterior eye shape assessment by magnetic resonance imaging (MRI) is used to study myopia. We tested the hypothesis that optical coherence tomography (OCT), as an alternative, could measure posterior eye shape similarly to MRI. Methods Macular spectral-domain OCT and brain MRI images previously acquired as part of the Singapore Epidemiology of Eye Diseases study were analyzed. The right eye in the MRI and OCT images was automatically segmented. Optical coherence tomography segmentations were corrected for optical and display distortions requiring biometry data. The segmentations were fitted to spheres and ellipsoids to obtain the posterior eye radius of curvature (Rc) and asphericity (Qxz). The differences in Rc and Qxz measured by MRI and OCT were tested using paired t-tests. Categorical assignments of prolateness or oblateness using Qxz were compared. Results Fifty-two subjects (67.8 ± 5.6 years old) with spherical equivalent refraction from +0.50 to −5.38 were included. The mean paired difference between MRI and original OCT posterior eye Rc was 24.03 ± 46.49 mm (P = 0.0005). For corrected OCT images, the difference in Rc decreased to −0.23 ± 2.47 mm (P = 0.51). The difference between MRI and OCT asphericity, Qxz, was −0.052 ± 0.343 (P = 0.28). However, categorical agreement was only moderate (κ = 0.50). Conclusions Distortion-corrected OCT measurements of Rc and Qxz were not statistically significantly different from MRI, although the moderate categorical agreement suggests that individual differences remained. This study provides evidence that with distortion correction, noninvasive office-based OCT could potentially be used instead of MRI for the study of posterior eye shape. PMID:27409473

  17. Stroke etiology is associated with outcome in posterior circulation stroke

    PubMed Central

    Chung, Chih-Ping; Yong, Chin-Sern; Chang, Feng-Chi; Sheng, Wen-Yung; Huang, Hui-Chi; Tsai, Jui-Yao; Hsu, Hung-Yi; Hu, Han-Hwa

    2015-01-01

    Objective Stroke research and clinical trials have focused mainly on anterior circulation stroke (ACS). Since clinical characteristics, mechanisms, and outcomes of posterior circulation stroke (PCS) have been reported different from ACS, more PCS studies are required, particularly researching the etiologies, to help establish an optimal management strategy. Methods The present study analyzed patients of PCS who were consecutively admitted and registered in Taipei Veterans General Hospital Stroke Registry between 1 January 2012 to 28 February 2014. We demonstrated the distribution of etiologies, compared the clinical characteristics/outcomes among different etiology groups, and used univariate/multivariate analyses to identify the predictors for poor functional outcome (modified Rankin Scale ≥5) at discharge and 3 month. Results About 286 patients of PCS were included for analyses. Basilar artery atheromatous branch occlusive disease (BABO, 28.0%) and large artery dissection (25.9%) were the two most common etiologies, followed by large artery atherosclerotic stenosis/occlusion (LAA, 20.6%), cardioembolism (CE, 18.5%) and small vessel disease (7.0%). Age, vascular risk factors, infarct locations and patterns, and outcomes were different among these five etiology groups. Multivariate analyses showed that age >70 y/o (discharge/3 month, OR, 95% CI: 3.05, 1.23–7.56/8.39, 2.32–30.33), admission NIH Stroke Scale >9 (19.50, 8.69–43.75/13.45, 5.59–32.39), and etiology (LAA versus BABO: 5.00, 1.58–15.83/4.00, 1.19–13.4; CE versus BABO: 3.36, 1.02–11.09/4.66, 1.40–15.46) were independently associated with poor functional outcome. Interpretation The etiologies of PCS are heterogeneous and shown to be associated with functional outcomes. Our results have shed lights on future pathophysiological research and designs of clinical trials for PCS. PMID:26000323

  18. Panic-like defensive behavior but not fear-induced antinociception is differently organized by dorsomedial and posterior hypothalamic nuclei of Rattus norvegicus (Rodentia, Muridae)

    PubMed Central

    Biagioni, A.F.; Silva, J.A.; Coimbra, N.C.

    2012-01-01

    The hypothalamus is a forebrain structure critically involved in the organization of defensive responses to aversive stimuli. Gamma-aminobutyric acid (GABA)ergic dysfunction in dorsomedial and posterior hypothalamic nuclei is implicated in the origin of panic-like defensive behavior, as well as in pain modulation. The present study was conducted to test the difference between these two hypothalamic nuclei regarding defensive and antinociceptive mechanisms. Thus, the GABAA antagonist bicuculline (40 ng/0.2 µL) or saline (0.9% NaCl) was microinjected into the dorsomedial or posterior hypothalamus in independent groups. Innate fear-induced responses characterized by defensive attention, defensive immobility and elaborate escape behavior were evoked by hypothalamic blockade of GABAA receptors. Fear-induced defensive behavior organized by the posterior hypothalamus was more intense than that organized by dorsomedial hypothalamic nuclei. Escape behavior elicited by GABAA receptor blockade in both the dorsomedial and posterior hypothalamus was followed by an increase in nociceptive threshold. Interestingly, there was no difference in the intensity or in the duration of fear-induced antinociception shown by each hypothalamic division presently investigated. The present study showed that GABAergic dysfunction in nuclei of both the dorsomedial and posterior hypothalamus elicit panic attack-like defensive responses followed by fear-induced antinociception, although the innate fear-induced behavior originates differently in the posterior hypothalamus in comparison to the activity of medial hypothalamic subdivisions. PMID:22437484

  19. Panic-like defensive behavior but not fear-induced antinociception is differently organized by dorsomedial and posterior hypothalamic nuclei of Rattus norvegicus (Rodentia, Muridae).

    PubMed

    Biagioni, A F; Silva, J A; Coimbra, N C

    2012-04-01

    The hypothalamus is a forebrain structure critically involved in the organization of defensive responses to aversive stimuli. Gamma-aminobutyric acid (GABA)ergic dysfunction in dorsomedial and posterior hypothalamic nuclei is implicated in the origin of panic-like defensive behavior, as well as in pain modulation. The present study was conducted to test the difference between these two hypothalamic nuclei regarding defensive and antinociceptive mechanisms. Thus, the GABA(A) antagonist bicuculline (40 ng/0.2 µL) or saline (0.9% NaCl) was microinjected into the dorsomedial or posterior hypothalamus in independent groups. Innate fear-induced responses characterized by defensive attention, defensive immobility and elaborate escape behavior were evoked by hypothalamic blockade of GABA(A) receptors. Fear-induced defensive behavior organized by the posterior hypothalamus was more intense than that organized by dorsomedial hypothalamic nuclei. Escape behavior elicited by GABA(A) receptor blockade in both the dorsomedial and posterior hypothalamus was followed by an increase in nociceptive threshold. Interestingly, there was no difference in the intensity or in the duration of fear-induced antinociception shown by each hypothalamic division presently investigated. The present study showed that GABAergic dysfunction in nuclei of both the dorsomedial and posterior hypothalamus elicit panic attack-like defensive responses followed by fear-induced antinociception, although the innate fear-induced behavior originates differently in the posterior hypothalamus in comparison to the activity of medial hypothalamic subdivisions.

  20. Extreme variability in posterior slope of the proximal tibia: measurements on 2395 CT scans of patients undergoing UKA?

    PubMed

    Nunley, Ryan M; Nam, Denis; Johnson, Staci R; Barnes, C Lowry

    2014-08-01

    Data regarding the posterior slope of the tibia (PTS) are limited and sometimes conflicting. The purpose of this study was to determine the native posterior tibial slope in patients undergoing a medial or lateral UKA. A retrospective review was performed on 2395 CT scans in patients indicated for UKA, and the PTS of the osteoarthritic compartment was measured relative to a plane set perpendicular to the sagittal, tibial mechanical axis. The mean preoperative PTS in patients undergoing medial UKA was 6.8°+3.3°, with 34.3% between 4° and 7°. The mean preoperative PTS in patients undergoing lateral UKA was 8.0°+3.3°, with 27.5% between 4° and 7°. If attempting to recreate a patient's preoperative tibial slope, a routine target of 5° to 7° will produce a posterior slope less than the patient's native anatomy in 47% of patients undergoing UKA. This is the first, large CT-based review of posterior slope variation of the proximal tibia in patients undergoing UKA.

  1. Using Particle Imaging Velocimetry to Measure Anterior-Posterior Velocity Gradients in the Excised Canine Larynx Model

    PubMed Central

    Khosla, Sid; Murugappan, Shanmugam; Lakhamraju, Raghavaraju; Gutmark, Ephraim

    2008-01-01

    Objectives To quantify the anterior-posterior velocity gradient, we studied the velocity flow fields above the vocal folds in both the midcoronal and midsagittal planes. It was also our purpose to use these fields to deduce the mechanisms that cause the anterior-posterior gradient and to determine whether the vortical structures are highly 3-dimensional. Methods Using the particle imaging velocimetry method for 5 excised canine larynges. we obtained phase-averaged velocity fields in the midcoronal and midsagittal planes for 30 phases of phonation. The velocity fields were determined synchronously with the vocal fold motion recorded by high-speed videography. Results The results show that immediately above the folds, there is no significant anterior-posterior velocity gradient. However, as the flow travels downstream, the laryngeal jet tends to narrow in width and skew toward the anterior commissure. Vortices are seen at the anterior and posterior edges of the flow. Conclusions The downstream narrowing in the midsagittal plane is consistent with and is probably due to a phenomenon known as axis switching. Axis switching also involves vortices in the sagittal and coronal planes bending in the axial plane. This results in highly 3-dimensional, complex vortical structures. However, there is remarkable cyclic repeatability of these vortices during a phonation cycle. PMID:18357838

  2. The adhesion GPCR latrophilin – a novel signaling cascade in oriented cell division and anterior-posterior polarity

    PubMed Central

    Winkler, Jana; Prömel, Simone

    2016-01-01

    ABSTRACT Although several signaling pathways in oriented cell division have been well characterized such as delta/notch inductions or wnt/frizzled-based anterior-posterior polarity, there is strong evidence for additional signal pathways controlling early anterior-posterior polarity decisions. The homolog of the adhesion G protein-coupled receptor latrophilin, LAT-1 has been identified as a receptor essential for oriented cell division in an anterior-posterior direction of specific blastomeres in the early C. elegans embryo. We recently conducted a study aiming at clarifying the signals involved in LAT-1 function. We identified a Gs protein/adenylyl cyclase/cAMP pathway in vitro and demonstrated its physiological relevance in oriented cell division. By interaction with a Gs protein LAT-1 elevates cAMP levels. These data indicate that G-protein signaling in oriented cell division is not solely GPCR-independent. This commentary will discuss our findings in the context of the current knowledge of mechanisms controlling oriented cell division and anterior-posterior polarity. Further, we identify open questions which need to be addressed in the future. PMID:27383912

  3. Posterior Capsular Opacification in Preschool- and School-Age Patients after Pediatric Cataract Surgery without Posterior Capsulotomy

    PubMed Central

    Batur, Muhammed; Gül, Adem; Seven, Erbil; Can, Ertuğrul; Yaşar, Tekin

    2016-01-01

    Objectives: We aimed to evaluate the development of posterior capsular opacification (PCO) in preschool- and school-age children with cataract who underwent cataract surgery without posterior capsulotomy and anterior vitrectomy. Materials and Methods: The records of 30 eyes of 21 patients who underwent pediatric cataract surgery and intraocular lens (IOL) implantation were retrospectively reviewed. Patients’ age, PCO status and duration, need for neodymium-doped yttrium aluminium garnet (Nd:YAG) laser treatment based on coverage of visual axis, and follow-up period were recorded. Results: The mean age of the patients was 7.6±2.83 (4-12) years. Unilateral cataract surgery and IOL implantation were performed in 12 patients (57.14%) and bilateral cataract surgery and IOL implantation were performed in nine patients (42.86%). Average follow-up time was 17.7±22.67 (3-83) months. PCO developed in 21 eyes (70%) and covered the visual axis in 15 eyes (50%), which therefore required Nd:YAG laser posterior capsulotomy. The mean duration of postoperative PCO development was 8.91±18.7 months (1 week-71 months). Conclusion: We believe that with adequately experienced surgeons, performing both cataract surgery and posterior capsulotomy with anterior vitrectomy in the same session is appropriate for selected preschool- and school-age children with cataract. PMID:28058161

  4. Posterior auricular pain caused by the trigger points in the sternocleidomastoid muscle aggravated by psychological factors -A case report-.

    PubMed

    Min, Sam Hong; Chang, Seong-Ho; Jeon, Se Keun; Yoon, Seung Zhoo; Park, Ji-Yong; Shin, Hye Won

    2010-12-01

    Psychological factors play a significant role in the pain mechanism, and psychological approaches may be useful complements to traditional medical and surgical treatments in pain management. The authors report a case of recurrent severe posterior auricular pain caused by trigger points in the right sternocleidomastoid muscle and influenced by stressful psychological situations (e.g., family affairs, job loss) in a 50-year-old man.

  5. Posterior arch C-1 screw technique: a cadaveric comparison study.

    PubMed

    Moisi, Marc; Fisahn, Christian; Tkachenko, Lara; Jeyamohan, Shiveindra; Reintjes, Stephen; Grunert, Peter; Norvell, Daniel C; Tubbs, R Shane; Page, Jeni; Newell, David W; Nora, Peter; Oskouian, Rod J; Chapman, Jens

    2017-03-17

    OBJECTIVE Posterior atlantoaxial stabilization and fusion using C-1 lateral mass screw fixation has become commonly used in the treatment of instability and for reconstructive indications since its introduction by Goel and Laheri in 1994 and modification by Harms in 2001. Placement of such lateral mass screws can be challenging because of the proximity to the spinal cord, vertebral artery, an extensive venous plexus, and the C-2 nerve root, which overlies the designated starting point on the posterior center of the lateral mass. An alternative posterior access point starting on the posterior arch of C-1 could provide a C-2 nerve root-sparing starting point for screw placement, with the potential benefit of greater directional control and simpler trajectory. The authors present a cadaveric study comparing an alternative strategy (i.e., a C-1 screw with a posterior arch starting point) to the conventional strategy (i.e., using the lower lateral mass entry site), specifically assessing the safety of screw placement to preserve the C-2 nerve root. METHODS Five US-trained spine fellows instrumented 17 fresh human cadaveric heads using the Goel/Harms C-1 lateral mass (GHLM) technique on the left and the posterior arch lateral mass (PALM) technique on the right, under fluoroscopic guidance. After screw placement, a CT scan was obtained on each specimen to assess for radiographic screw placement accuracy. Four faculty spine surgeons, blinded to the surgeon who instrumented the cadaver, independently graded the quality of screw placement using a modified Upendra classification. RESULTS Of the 17 specimens, the C-2 nerve root was anatomically impinged in 13 (76.5%) of the specimens. The GHLM technique was graded Type 1 or 2, which is considered "acceptable," in 12 specimens (70.6%), and graded Type 3 or 4 ("unacceptable") in 5 specimens (29.4%). In contrast, the PALM technique had 17 (100%) of 17 graded Type 1 or 2 (p = 0.015). There were no vertebral artery injuries found

  6. The posterior neural plate in axolotl gives rise to neural tube or turns anteriorly to form somites of the tail and posterior trunk.

    PubMed

    Taniguchi, Yuka; Kurth, Thomas; Weiche, Susanne; Reichelt, Saskia; Tazaki, Akira; Perike, Srikanth; Kappert, Verena; Epperlein, Hans-Henning

    2017-02-15

    Classical grafting experiments in the Mexican axolotl had shown that the posterior neural plate of the neurula is no specified neuroectoderm but gives rise to somites of the tail and posterior trunk. The bipotentiality of this region with neuromesodermal progenitor cell populations was revealed more recently also in zebrafish, chick, and mouse. We reinvestigated the potency of the posterior plate in axolotl using grafts from transgenic embryos, immunohistochemistry, and in situ hybridization. The posterior plate is brachyury-positive except for its more anterior parts which express sox2. Between anterior and posterior regions of the posterior plate a small domain with sox2+ and bra+ cells exists. Lineage analysis of grafted GFP-labeled posterior plate tissue revealed that posterior GFP+ cells move from dorsal to ventral, form the posterior wall, turn anterior bilaterally, and join the gastrulated paraxial presomitic mesoderm. More anterior sox2+/GFP+ cells, however, are integrated into the developing spinal cord. Tail notochord is formed from axial mesoderm involuted already during gastrulation. Thus the posterior neural plate is a postgastrula source of paraxial mesoderm, which performs an anterior turn, a novel morphogenetic movement. More anterior plate cells, in contrast, do not turn anteriorly but become specified to form tail spinal cord.

  7. Posterior reversible encephalopathy syndrome associated with left horizontal gaze palsy

    PubMed Central

    Studyvin, Sarah; Al-Halawani, Moh’d; Amireh, Sawsan; Thawabi, Mohammad

    2017-01-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by rapid onset of symptoms including headache, seizures, altered consciousness, and visual disturbance, as well as radiologic findings of focal reversible vasogenic edema. Multiple visual disturbances have been described in PRES, such as hemianopia, visual neglect, auras, visual hallucinations, and cortical blindness. However, horizontal gaze palsy has not been previously reported. We report a 72-year-old female who presented with blurred vision, severe headache, lethargy, and later developed seizures. She was found to have left horizontal gaze palsy with intact vestibulo-ocular reflex. Brain magnetic resonance imaging (MRI) showed severe edema throughout the subcortical white matter, and signal in the posterior parietal and occipital lobes. She was diagnosed with PRES associated with supranuclear gaze palsy. PMID:28361069

  8. Transoral decompression and posterior stabilisation in Morquio's disease.

    PubMed Central

    Ashraf, J; Crockard, H A; Ransford, A O; Stevens, J M

    1991-01-01

    A 3.5 year old boy with Morquio's disease was referred with a persisting left hemiparesis four months after a fall and was found to have craniocervical junction compression due to atlantoaxial subluxation and significant anterior soft tissue compression. Transient unconsciousness at the time of the fall was probably due to medullary concussion as a result of hyperextension, not a head injury. Spinal cord compression due to atlantoaxial subluxation at the craniovertebral junction is a major cause of disability and death in these patients. Once cervical myelopathy appears, early posterior occipitocervical fusion has been advocated in order to arrest the progression of neurological disability and this is successful in most cases. This conventional approach was considered unsafe because of the significant anterior compression. A combined anterior transoral decompression with posterior fusion to deal with this particularly difficult problem is described. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:1755646

  9. [Macular threshold after ECCE and posterior chamber IOL implantation].

    PubMed

    Baltatzis, S; Georgopoulos, G; Andreanos, D

    1989-01-01

    In the present paper, the macular threshold after ECCE and posterior chamber intraocular lens implantation, was studied in an effort to determine the time period needed for full postoperative recovery of macular function. We evaluated 22 eyes in 20 patients who underwent extracapsular cataract extraction and posterior chamber IOL implantation. There were 12 men and 8 women between the ages of 40 and 62 years with mean age of 53 years. Postoperative visual field testing was performed within the central 4 degrees with an automated static perimeter (Humphrey Visual Field Analyser), using a macular threshold test pattern. It has been established that central retinal sensitivity in pseudophakia shows a postoperative decrease and consequently recovers to almost normal levels within one month. The exact cause of this reduction remains under discussion and further control mainly with fluorescein angiography is necessary.

  10. Posterior polymorphous dystrophy of the cornea. An ultrastructural study.

    PubMed

    de Felice, G P; Braidotti, P; Viale, G; Bergamini, F; Vinciguerra, P

    1985-01-01

    A corneal button excised from a 2-month-old infant with congenital posterior polymorphous dystrophy of the cornea, a rare disease affecting Descemet's membrane and endothelium, was examined by electron microscopy. We observed irregularly arranged, sometimes multilayered cells with marked epithelial features, lining the posterior surface of the cornea in place of the endothelium, and Descemet's membrane with focal alterations sometimes involving all of its layers. We interpreted these abnormal cells as epithelial-like cells. As these findings were in a very young patient, which is unusual, we concluded that the onset of the disease may take place in the early period of intrauterine life, corresponding to the beginning of Descemet's membrane production.

  11. Posterior Fixation Techniques in the Subaxial Cervical Spine

    PubMed Central

    Ghori, Ahmer; Makanji, Heeren; Cha, Thomas

    2015-01-01

    This article reviews the historical context, indications, techniques, and complications of four posterior fixation techniques to stabilize the subaxial cervical spine. Specifically, posterior wiring, laminar screw fixation, lateral mass fixation, and pedicle screw fixation are among the common methods of operative fixation of the subaxial cervical spine. While wiring and laminar screw fixation are now rarely used, both lateral mass and pedicle screw fixation are technically challenging and present the risk of significant complications if performed incorrectly. With a sound understanding of anatomy and rigorous preoperative evaluation of bony structures, both lateral mass and pedicle screw fixation provide a safe and reliable method for subaxial cervical spine fixation. PMID:26594602

  12. Posterior left atrial wall hematoma mimicking cystic intracavitary atrial mass.

    PubMed

    Bahnacy, Yasser; Suresh, Cheriyil; Dawoud, Hamed; Zubaid, Mohammad

    2010-10-01

    Atrial myxoma is the most common benign primary tumor of the heart most commonly in the left atrium (LA). Cystic or cavitated intracardiac masses are rare. We report the case of a 43-year-old male patient admitted with chest infection, hemoptysis, and severe respiratory distress, who had to be ventilated. Chest computed tomography showed bilateral lung consolidation with large mass occupying the region of the LA. Transthoracic echocardiography and transesophageal echocardiography showed a large intracavitary left atrial cystic mobile mass. Open-heart surgical exploration did not show any mass inside the LA. A posterior left atrial wall hematoma was found and evacuated. Biopsies confirmed the presence of blood clots. Posterior left atrial wall hematoma may appear as left atrial intracavitary cystic mass and should be included in the differential diagnosis of cystic left atrial mass.

  13. Posterior reversible encephalopathy syndrome following a scorpion sting.

    PubMed

    Porcello Marrone, Luiz Carlos; Marrone, Bianca Fontana; Neto, Felipe Kalil; Costa, Francisco Cosme; Thomé, Gustavo Gomes; Aramburu, Martin Brandolt; Schilling, Lucas Porcello; Pascoal, Tharick Ali; Gadonski, Giovani; Huf Marrone, Antônio Carlos; da Costa, Jaderson Costa

    2013-10-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity not yet understood, that is present with transient neurologic symptoms and particular radiological findings. The most common imaging pattern in PRES is the presence of edema in the white matter of the posterior portions of both cerebral hemispheres. The cause of PRES is unclear. We report a case of 13-year-old male who was stung by a scorpion and developed a severe headache, visual disturbance, and seizures and had the diagnosis of PRES with a good outcome. Numerous factors can trigger this syndrome, most commonly: acute elevation of blood pressure, abnormal renal function, and immunosuppressive therapy. There are many cases described showing the relationship between PRES and eclampsia, transplantation, neoplasia and chemotherapy treatment, systemic infections, renal disease acute, or chronic. However, this is the first case of PRES following a scorpion sting.

  14. [Cysts in the posterior triangle of the neck in adults].

    PubMed

    Brea-Álvarez, Beatriz; Roldán-Hidalgo, Amaya

    2015-01-01

    Cystic lesions of the posterior triangle are a pathologic entity whose diagnosis is made in the first two years of life. Its presentation in adulthood is an incidental finding and the differential diagnosis includes cystic lymphangioma, lymphatic metastasis of thyroid cancer and branchial cyst. Often with the finding of a cervical lump, FNA is made before diagnostic imaging is performed, however, this procedure is not always advisable. We reviewed the cases of patients who came last year to our department with a cystic mass in this location and correlating the imaging findings with pathologic specimen. We show characteristic findings of these lesions in order to make an early diagnosis and thus to get the approach and treatment appropriate of adult patients with a cystic lesion in the posterior cervical triangle.

  15. Evaluation of arthroscopic treatment of posterior shoulder instability

    PubMed Central

    Garcia, José Carlos; Maia, Lucas Russo; Fonseca, Juliano Rocha; Zabeu, José Luís Amim; Garcia, Jesely Pereira Myrrha

    2015-01-01

    OBJECTIVE: To provide data for the analysis of arthroscopy as a method of surgical treatment for shoulder and discuss its actual indications and preliminary results. METHODS: We evaluated 15 patients submitted to reverse Bankart arthroscopic surgery. We used the UCLA (University of California at Los Angeles) score to measure the results before surgery and 12 months thereafter. RESULTS: The average UCLA score changed from 26.67±0.25 (SD 0.97) before surgery to 34.20±0.53 (SD 2.04) after surgery. The effectiveness of surgery was 93%. In five cases loose bodies were found. A patient undergoing remplissage was evaluated separately. The data did not change after 24 months post-surgery. CONCLUSION: The arthroscopic treatment of posterior shoulder instability and posterior dislocation of the shoulder has been proved feasible and results in our series followed the same trends as in the literature. Level of Evidence III, Transversal Retrospective Study. PMID:26207089

  16. Management of noninfectious posterior uveitis with intravitreal drug therapy

    PubMed Central

    Tan, Hui Yi; Agarwal, Aniruddha; Lee, Cecilia S; Chhablani, Jay; Gupta, Vishali; Khatri, Manoj; Nirmal, Jayabalan; Pavesio, Carlos; Agrawal, Rupesh

    2016-01-01

    Uveitis is an important cause of vision loss worldwide due to its sight-threatening complications, especially cystoid macular edema, as well as choroidal neovascularization, macular ischemia, cataract, and glaucoma. Systemic corticosteroids are the mainstay of therapy for noninfectious posterior uveitis; however, various systemic side effects can occur. Intravitreal medication achieves a therapeutic level in the vitreous while minimizing systemic complications and is thus used as an exciting alternative. Corticosteroids, antivascular endothelial growth factors, immunomodulators such as methotrexate and sirolimus, and nonsteroidal anti-inflammatory drugs are currently available for intravitreal therapy. This article reviews the existing literature for efficacy and safety of these various options for intravitreal drug therapy for the management of noninfectious uveitis (mainly intermediate, posterior, and panuveitis). PMID:27789936

  17. Posterior sternoclavicular dislocations--a diagnosis easily missed.

    PubMed Central

    Thomas, D. P.; Davies, A.; Hoddinott, H. C.

    1999-01-01

    Posterior dislocation of the sternoclavicular joint is a relatively rare injury and can be difficult to diagnose acutely. We report 3 cases of posterior dislocation of the sternoclavicular joint who presented to the Accident & Emergency Department within a 3 month period. All 3 patients had sustained a significant injury to the shoulder region and complained of pain around the medial clavicle. Two patients had also complained of dysphagia following the injury. Plain X-rays of the shoulder and chest were reported as normal by junior and senior medical staff. The diagnosis was delayed until CT scans were performed, and once this was established, open reduction and stabilisation was performed. Images Figure 1 Figure 2 Figure 3 p204-a PMID:10364956

  18. Absence of Posterior Triangle: Clinical and Embryological Perspective

    PubMed Central

    Singh, Shikha; Loh, Hitendra Kumar; Mehta, Vandana; Suri, Rajesh Kumar

    2017-01-01

    Sternocleidomastoid (SCM) and Trapezius (TM) muscle present in the cervical region serves as an important landmark in forming boundaries of posterior triangle of neck. This case reports a continuous muscle sheet obscuring the left posterior triangle in the neck of a 60-year-old Indian male cadaver. An unfamiliar oval gap was observed in its posterosuperior portion. Description of such a variant in anatomical literature is rare and is scarcely reported. An attempt has been made to portray its embryological and phylogenetic basis. In addition authors have endeavoured to discuss its clinical implications. Awareness of such anatomical variations is relevant for the operating surgeons in their endeavour to perform various reconstruction surgeries of head and neck, radiologists while concluding various levels in Computed Tomography (CT) and Magnetic Resonance Images (MRI) of the region and to the anaesthetists in their search for nerves and vessels while attempting various anaesthetic procedures. PMID:28384846

  19. Lumbo-costo-vertebral syndrome with posterior spinal dysraphism.

    PubMed

    Kumar, G Samson Sujit; Kulkarni, Vaijayantee; Haran, R P

    2005-09-01

    Lumbo-costo-vertebral syndrome, which includes abnormalities of the vertebral bodies, ribs and trunk musculature, is very rare and only few cases have been reported. We report a case of 18-month-old female child with absent ribs, hemivertebrae, superior lumbar hernia (features of lumbo-costo-vertebral syndrome) and posterior spinal dysraphism, which to our knowledge is the first case in the English literature with such a combination of defects. Embryology and management of the case is discussed.

  20. Detachments of the retinal pigment epithelium at the posterior pole.

    PubMed

    Noble, K G; Levitzky, M J; Carr, R E

    1976-08-01

    Multiple vitelliform cysts of the retina, a disorder of unknown cause in which there are multiple detachments of the retinal pigment epithelium at the posterior pole, occurred in five patients. In four patients all lesions were located outside the parafoveal area while one patient showed bilateral foveal elevations associated with more eccentric detachments. Several patients showed slow resolution of some of the detachments with mild disturbances of the pigment epithelium.

  1. Stenting for a symptomatic posterior cerebral artery stenosis.

    PubMed

    Xu, Gelin; Zheng, Ling; Zhou, Zhiming; Liu, Xinfeng

    2009-05-01

    Evolvement of endovascular devices and increase of operator expertise have made angioplasty and stenting in intracranial vessels technically possible. Stenting has been reported in treating stenosis in middle and anterior cerebral arteries with favorable outcomes. However, the feasibility of stenting for stenosis in posterior cerebral artery (PCA) has not been established. We report a patient with progressive focal cerebral ischemic symptoms, which were arrested after reconstruction of the associated PCA stenosis with stenting.

  2. Classical caesarean section through the posterior uterine wall.

    PubMed

    Bolaji, I I; Rafla, N M; Mylotte, M J

    1992-02-01

    We report a case of myomectomy and classical caesarean section through the posterior uterine wall necessitated by 180 degrees dextro-rotation of a gravid uterus with large fibroids. The non-specific clinical course and rarity of pathological torsion of the gravid uterus makes the preoperative diagnosis difficult. Ultrasound recognition antenatally of a fibroid changing its position should help with the prediction preoperatively of uterine rotation.

  3. Cadherin-mediated adhesion regulates posterior body formation

    PubMed Central

    Harrington, Michael J; Hong, Elim; Fasanmi, Oluwafoyinsa; Brewster, Rachel

    2007-01-01

    Background The anterior-posterior axis of the vertebrate embryo undergoes a dramatic elongation during early development. Convergence and extension of the mesoderm, occurring during gastrulation, initiates the narrowing and lengthening of the embryo. However the lengthening of the axis continues during post-gastrula stages in the tailbud region, and is thought to involve convergent extension movements as well as other cell behaviors specific to posterior regions. Results We demonstrate here, using a semi-dominant N-cadherin allele, that members of the classical cadherin subfamily of cell-cell adhesion molecules are required for tailbud elongation in the zebrafish. In vivo imaging of cell behaviors suggests that the extension of posterior axial mesodermal cells is impaired in embryos that carry the semi-dominant N-cadherin allele. This defect most likely results from a general loss of cell-cell adhesion in the tailbud region. Consistent with these observations, N-cadherin is expressed throughout the tailbud during post-gastrulation stages. In addition, we show that N-cadherin interacts synergistically with vang-like 2, a member of the non-canonical Wnt signaling/planar cell polarity pathway, to mediate tail morphogenesis. Conclusion We provide the first evidence here that N-cadherin and other members of the classical cadherin subfamily function in parallel with the planar cell polarity pathway to shape the posterior axis during post-gastrulation stages. These findings further highlight the central role that adhesion molecules play in the cellular rearrangements that drive morphogenesis in vertebrates and identify classical cadherins as major contributors to tail development. PMID:18045497

  4. Trigeminal autonomic cephalgia caused by recurrent posterior scleritis.

    PubMed

    Alim-Marvasti, Ali; Ho, Jason; Weatherall, Mark; Patel, Maneesh; George, Sheena; Viegas, Stuart

    2016-12-01

    A 40-year-old woman presented with a side-locked headache with autonomic features, which then switched sides before reverting to the original side. The atypical features of side swapping, partial response to indometacin and abnormal optic disc appearances ultimately led to a diagnosis of recurrent posterior scleritis. We discuss the differential diagnosis of trigeminal autonomic cephalgias and its secondary causes, and provide practical pointers for its investigation and management.

  5. Epinephrine-induced posterior reversible encephalopathy syndrome: a case report.

    PubMed

    Gharabawy, Ramez; Pothula, Vijayasimha R; Rubinshteyn, Vladimir; Silverberg, Michael; Gave, Asaf A

    2011-09-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare disorder that is usually associated with hypertensive crises. It is often missed but may be diagnosed by head computed tomographic (CT) scan or magnetic resonance imaging. An adolescent man presented for elective right shoulder arthroscopic bankart repair. Arthroscopy was performed using a solution of normal saline with 3.3 mg/L of epinephrine for irrigation. Postoperatively, the patient presented with hypertension and epileptiform activity. A CT scan of the head showed PRES.

  6. Pure alexia and right hemiachromatopsia in posterior dementia.

    PubMed Central

    Freedman, L; Costa, L

    1992-01-01

    A 66 year old, right handed woman presented with pure alexia and right hemiachromatopsia (PARH) in the context of a posterior dementia. PARH was accompanied by prosopagnosia, 2-D object agnosia, and environmental agnosia. Visual fields were normal to confrontation testing. The pathological anatomy of PARH involves circumscribed damage to the lingual and fusiform gyri and paraventricular white matter of the left occipital cortex, two contiguous cortical regions functionally specialised for processing colour and word form information, respectively. PMID:1619420

  7. Early treatment of posterior crossbite - a randomised clinical trial

    PubMed Central

    2013-01-01

    Background The aim of this randomised clinical trial was to assess the effect of early orthodontic treatment in contrast to normal growth effects for functional unilateral posterior crossbite in the late deciduous and early mixed dentition by means of three-dimensional digital model analysis. Methods This randomised clinical trial was assessed to analyse the orthodontic treatment effects for patients with functional unilateral posterior crossbite in the late deciduous and early mixed dentition using a two-step procedure: initial maxillary expansion followed by a U-bow activator therapy. In the treatment group 31 patients and in the control group 35 patients with a mean age of 7.3 years (SD 2.1) were monitored. The time between the initial assessment (T1) and the follow-up (T2) was one year. The orthodontic analysis was done by a three-dimensional digital model analysis. Using the ‘Digimodel’ software, the orthodontic measurements in the maxilla and mandible and for the midline deviation, the overjet and overbite were recorded. Results Significant differences between the control and the therapy group at T2 were detected for the anterior, median and posterior transversal dimensions of the maxilla, the palatal depth, the palatal base arch length, the maxillary arch length and inclination, the midline deviation, the overjet and the overbite. Conclusions Orthodontic treatment of a functional unilateral posterior crossbite with a bonded maxillary expansion device followed by U-bow activator therapy in the late deciduous and early mixed dentition is an effective therapeutic method, as evidenced by the results of this RCT. It leads to three-dimensional therapeutically induced maxillary growth effects. Dental occlusion is significantly improved, and the prognosis for normal craniofacial growth is enhanced. Trial registration Registration trial DRKS00003497 on DRKS PMID:23339736

  8. Popliteal artery injury during posterior cruciate ligament reconstruction.

    PubMed

    Cenni, Marcos Henrique Frauendorf; do Nascimento, Bruno Fajardo; Carneiro, Guilherme Galvão Barreto; de Andrade, Rodrigo Cristiano; Pinheiro Júnior, Lúcio Flávio Biondi; Nicolai, Oscar Pinheiro

    2015-01-01

    This study reports a case of popliteal artery injury during arthroscopic reconstruction of the posterior cruciate ligament. The evolution of the injury is described and comments are made regarding the anatomy of this artery and potential risks of this surgical technique. This study had the aims of alerting the medical community, especially knee surgeons, regarding a severe surgical complication and discussing the ways of preventing it.

  9. An Injectable Method for Posterior Lateral Spine Fusion

    DTIC Science & Technology

    2013-09-01

    spine area but is also used to treat diseases in the cervical and thoracic spine regions [2]. Spinal fusion has been developed with the bone...Lateral Spine Fusion PRINCIPAL INVESTIGATOR: Dr. Elizabeth Olmsted-Davis CONTRACTING ORGANIZATION: Baylor College of Medicine...Method for Posterior Lateral Spine Fusion 5b. GRANT NUMBER W81XWH-12-1-0475 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Elizabeth A

  10. Expression Patterns of Extracellular Matrix Proteins during Posterior Commissure Development

    PubMed Central

    Stanic, Karen; Saldivia, Natalia; Förstera, Benjamín; Torrejón, Marcela; Montecinos, Hernán; Caprile, Teresa

    2016-01-01

    Extracellular matrix (ECM) molecules are pivotal for central nervous system (CNS) development, facilitating cell migration, axonal growth, myelination, dendritic spine formation, and synaptic plasticity, among other processes. During axon guidance, the ECM not only acts as a permissive or non-permissive substrate for navigating axons, but also modulates the effects of classical guidance cues, such as netrin or Eph/ephrin family members. Despite being highly important, little is known about the expression of ECM molecules during CNS development. Therefore, this study assessed the molecular expression patterns of tenascin, HNK-1, laminin, fibronectin, perlecan, decorin, and osteopontin along chick embryo prosomere 1 during posterior commissure development. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. Located in the dorso-caudal portion of prosomere 1, posterior commissure axons primarily arise from the neurons of basal pretectal nuclei that run dorsally to the roof plate midline, where some turn toward the ipsilateral side. Expressional analysis of ECM molecules in this area these revealed to be highly arranged, and molecule interactions with axon fascicles suggested involvement in processes other than structural support. In particular, tenascin and the HNK-1 epitope extended in ventro-dorsal columns and enclosed axons during navigation to the roof plate. Laminin and osteopontin were expressed in the midline, very close to axons that at this point must decide between extending to the contralateral side or turning to the ipsilateral side. Finally, fibronectin, decorin, and perlecan appeared unrelated to axonal pathfinding in this region and were instead restricted to the external limiting membrane. In summary, the present report provides evidence for an intricate expression of different extracellular molecules that may cooperate in guiding posterior commissure axons. PMID:27733818

  11. Human posterior auditory cortex gates novel sounds to consciousness.

    PubMed

    Jääskeläinen, Iiro P; Ahveninen, Jyrki; Bonmassar, Giorgio; Dale, Anders M; Ilmoniemi, Risto J; Levänen, Sari; Lin, Fa-Hsuan; May, Patrick; Melcher, Jennifer; Stufflebeam, Steven; Tiitinen, Hannu; Belliveau, John W

    2004-04-27

    Life or death in hostile environments depends crucially on one's ability to detect and gate novel sounds to awareness, such as that of a twig cracking under the paw of a stalking predator in a noisy jungle. Two distinct auditory cortex processes have been thought to underlie this phenomenon: (i) attenuation of the so-called N1 response with repeated stimulation and (ii) elicitation of a mismatch negativity response (MMN) by changes in repetitive aspects of auditory stimulation. This division has been based on previous studies suggesting that, unlike for the N1, repetitive "standard" stimuli preceding a physically different "novel" stimulus constitute a prerequisite to MMN elicitation, and that the source loci of MMN and N1 are different. Contradicting these findings, our combined electromagnetic, hemodynamic, and psychophysical data indicate that the MMN is generated as a result of differential adaptation of anterior and posterior auditory cortex N1 sources by preceding auditory stimulation. Early ( approximately 85 ms) neural activity within posterior auditory cortex is adapted as sound novelty decreases. This alters the center of gravity of electromagnetic N1 source activity, creating an illusory difference between N1 and MMN source loci when estimated by using equivalent current dipole fits. Further, our electroencephalography data show a robust MMN after a single standard event when the interval between two consecutive novel sounds is kept invariant. Our converging findings suggest that transient adaptation of feature-specific neurons within human posterior auditory cortex filters superfluous sounds from entering one's awareness.

  12. Evaluating pathogenic dementia variants in posterior cortical atrophy

    PubMed Central

    Carrasquillo, Minerva M.; Barber, Imelda; Lincoln, Sarah J.; Murray, Melissa E.; Camsari, Gamze Balci; Khan, Qurat ul Ain.; Nguyen, Thuy; Ma, Li; Bisceglio, Gina D.; Crook, Julia E.; Younkin, Steven G.; Dickson, Dennis W.; Boeve, Bradley F.; Graff-Radford, Neill R.; Morgan, Kevin; Ertekin-Taner, Nilüfer

    2015-01-01

    Posterior cortical atrophy (PCA) is an understudied visual impairment syndrome most often due to “posterior Alzheimer’s disease (AD)” pathology. Case studies detected mutations in PSEN1, PSEN2, GRN, MAPT and PRNP in subjects with clinical PCA. To detect the frequency and spectrum of mutations in known dementia genes in PCA, we screened 124 European-American subjects with clinical PCA (n=67) or posterior AD neuropathology (n=57) for variants in genes implicated in AD, frontotemporal dementia, and prion disease using NeuroX, a customized exome array. Frequencies in PCA of the variants annotated as pathogenic or potentially pathogenic were compared against ~4,300 European-American population controls from the NHLBI Exome Sequencing Project (ESP). We identified two rare variants not previously reported in PCA, TREM2 Arg47His and PSEN2 Ser130Leu. No other pathogenic or potentially pathogenic variants were detected in the screened dementia genes. In this first systematic variant screen of a PCA cohort, we report two rare mutations in TREM2 and PSEN2, validate our previously reported APOE ε4 association, and demonstrate the utility of NeuroX. PMID:26507310

  13. Automated measurement of anterior and posterior acetabular sector angles

    NASA Astrophysics Data System (ADS)

    Ibragimov, Bulat; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž

    2012-03-01

    In this paper, we propose a segmentation algorithm by which anatomical landmarks on the pelvis are extracted from computed tomography (CT) images. The landmarks are used to automatically define the anterior (AASA) and posterior acetabular sector angles (PASA) describing the degree of hip misalignment. The center of each femoral head is obtained by searching for the point at which most intensity gradient vectors defined at edge points intersect. The radius of each femoral head is computed by finding the sphere, positioned at the center of the femoral head, for which the normalized sum of gradient vector magnitudes on the sphere surface is maximal. The anterior and posterior corners of each acetabulum are searched for on a curve representing the acetabulum and defined by dynamic programming. The femoral head centers and anterior and posterior corners are used to calculate the AASA and PASA. The algorithm was applied to CT images of 120 normal subjects and the results were compared to ground truth values obtained by manual segmentation. The mean absolute difference (+/- standard deviation) between the obtained and ground truth values was 1.3 +/- 0.3 mm for the femoral head centers and 2.1 +/- 1.3 degrees for the acetabular angles.

  14. Congenital posterior urethral obstruction: re-do fulguration.

    PubMed

    Imaji, Reisuke; Dewan, Paddy A

    2002-09-01

    In patients with congenital posterior urethral obstruction, transurethral fulguration (TUF) is usually the treatment of choice if the patient is in a stable condition. However, few papers have described the proportion of patients who need further fulguration. We reviewed 83 boys with a congenital obstructive posterior urethral membrane (COPUM) to assess the role of re-do fulguration, as judged by prospective video recordings. Between December 1990 and March 2000, 83 boys (aged from newborn to 15 years) underwent cystourethroscopy for investigation of a urethral anomaly and were found to have a COPUM. TUF was performed endoscopically with a hook diathermy electrode. Two to 3 months later boys who had cauterisation had a further urethroscopy and diathermy as required. Of the 83 membranous lesions in the posterior urethra, 38 were considered severe, 20 moderate, and 21 minor. Four patients had inadequate data to be properly classified. Eighteen (47.4%) of the 38 patients who had a severe obstructive membrane equired further endoscopic intervention to obliterate residual membrane elements. As over 45% of patients who had a severe obstructing membrane needed further fulguration, it is important to follow patients carefully and to repeat the cystourethroscopy.

  15. Effect of four different intraocular lenses on posterior capsule opacification

    PubMed Central

    Duman, Rahmi; Karel, Fatih; Özyol, Pelin; Ateş, Can

    2015-01-01

    AIM To evaluate the impact of 4 different intraocular lenses (IOLs) on posterior capsule opacification (PCO) by comparing the neodymium: yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy rates. METHODS This retrospective study included 4970 eyes of 4013 cataract patients who underwent phacoemulsification and IOL implantation between January 2000 and January 2008 by the same surgeon at one clinic. Four different IOLs were assessed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies. RESULTS An Nd:YAG laser posterior capsulotomy was performed in 153 (3.07%) of the 4970 eyes. The mean follow-up time was 84mo for all of the IOL groups. The percentage of eyes developing PCO was significantly greater for the acrylic hydrophilic IOLs than for the hydrophobic IOLs, although eyes with acrylic hydrophilic IOLs did not require Nd:YAG laser capsulotomy as soon as eyes with acrylic hydrophobic IOLs. There was no difference between the long-term PCO rates when 1- and 3-piece acrylic hydrophobic IOLs were compared or when IOLs made of the same material but with different haptic angles were compared. CONCLUSION In this study, eyes with acrylic hydrophilic IOLs were more likely to develop PCO than those with acrylic hydrophobic IOLs. The lens design (1-piece versus 3-piece and varying haptic angles) did not affect the PCO rate. PMID:25709920

  16. Functional unilateral posterior crossbite effects on mastication movements using axiography.

    PubMed

    Salioni, Marco Antonio Canada; Pellizoni, Silmara Elena Papa; Guimarães, Antonio Sérgio; Juliano, Yara; Alonso, Luís Garcia

    2005-05-01

    This prospective study investigated the influence of functional unilateral posterior crossbite on mastication movements. The study group included 16 patients (nine girls and seven boys) with functional unilateral posterior crossbite involving three or more posterior teeth. A control group comprised 15 individuals (nine girls and six boys) with normal occlusion and the mean age of both groups was 9.17 years. The mandibular masticatory movements were registered, using computer axiography, for 30 seconds during chewing to determine the preference side of chewing. The patterns of the first, third, and fifth chewing cycles were compared with the preference side to establish whether they would predict the chewing preference side. The extent of the maximal lateral and vertical displacements of the mandible during chewing were compared between study and control groups. This study found that overall the left side was the preferred mastication side in 43.7% of individuals in the study and 46.7% in the control group. There was no relationship between the side of the crossbite and the masticatory preference side (Mc Nemar test, P = .5). No correlation was present between the patterns of chewing movements in the first, third, or fifth cycles. Both study and control groups showed similar maximal lateral and vertical mandible displacement.

  17. Macular Development in Aggressive Posterior Retinopathy of Prematurity

    PubMed Central

    Pandya, Hemang K.; Faia, Lisa J.; Robinson, Joshua; Drenser, Kimberly A.

    2015-01-01

    Purpose. To report anatomic outcomes after early and confluent laser photocoagulation of the entire avascular retina, including areas in close proximity to the fovea, in patients with APROP. We aspire to demonstrate fundoscopic evidence of transverse growth and macular development following laser treatment in APROP. Methods. Retrospective review of 6 eyes with APROP that underwent confluent laser photocoagulation of the entire avascular retina. Photographic fundoscopic imaging was performed using the RetCam to compare outcomes after treatment. Results. Mean birth weight and gestational age were 704.8 g and 24.33 weeks, respectively. There were 2 females and 1 male. The average time to laser was 9.3 weeks after birth, with the mean postmenstrual age of 34 weeks. Two eyes had zone 1 and 4 eyes had posterior zone 2 disease. Three eyes developed 4A detachments, which were successfully treated. All 6 eyes experienced transverse growth, with expansion of the posterior pole and anterior displacement of the laser treatment. Conclusion. Confluent photocoagulation of the entire avascular retina, regardless of foveal proximity, should be the mainstay for treating APROP. Examination should be conducted within 5–10 days to examine areas previously hidden by neovascularization to ensure prudent therapy. Macular development involves both transverse and anterior-posterior growth. PMID:26167498

  18. Macular Development in Aggressive Posterior Retinopathy of Prematurity.

    PubMed

    Pandya, Hemang K; Faia, Lisa J; Robinson, Joshua; Drenser, Kimberly A

    2015-01-01

    Purpose. To report anatomic outcomes after early and confluent laser photocoagulation of the entire avascular retina, including areas in close proximity to the fovea, in patients with APROP. We aspire to demonstrate fundoscopic evidence of transverse growth and macular development following laser treatment in APROP. Methods. Retrospective review of 6 eyes with APROP that underwent confluent laser photocoagulation of the entire avascular retina. Photographic fundoscopic imaging was performed using the RetCam to compare outcomes after treatment. Results. Mean birth weight and gestational age were 704.8 g and 24.33 weeks, respectively. There were 2 females and 1 male. The average time to laser was 9.3 weeks after birth, with the mean postmenstrual age of 34 weeks. Two eyes had zone 1 and 4 eyes had posterior zone 2 disease. Three eyes developed 4A detachments, which were successfully treated. All 6 eyes experienced transverse growth, with expansion of the posterior pole and anterior displacement of the laser treatment. Conclusion. Confluent photocoagulation of the entire avascular retina, regardless of foveal proximity, should be the mainstay for treating APROP. Examination should be conducted within 5-10 days to examine areas previously hidden by neovascularization to ensure prudent therapy. Macular development involves both transverse and anterior-posterior growth.

  19. Ganglion cyst on the posterior cruciate ligament: a case report

    PubMed Central

    Durante, Jaclyn A.

    2009-01-01

    Objective: To present the diagnostic and clinical features of a ganglion cyst located on the posterior cruciate ligament and create awareness amongst clinicians of this uncommon diagnosis. Clinical Features: A 24-year old woman complaining of intermittent left knee pain brought on by an increase in mileage during her training for a half-marathon. A diagnosis of mild chondromalacia patella and a ganglion cyst on the posterior cruciate ligament was made via diagnostic imaging. Intervention and outcome: Patient was followed up with imaging. The patient chose to withdraw a surgical consult due to patient preference. No conservative treatment was provided. Conclusion: Although chondromalacia patella is the more probable, a secondary diagnostic consideration in this patient could be a ganglion cyst. A ganglion cyst on the posterior cruciate ligament is an uncommon diagnosis and the clinical manifestations are variable and non-specific. It is important to be aware of its clinical features and to obtain appropriate methods of imaging to generate the diagnosis promptly. PMID:20037698

  20. Frontal-posterior coherence and cognitive function in older adults.

    PubMed

    Fleck, Jessica I; Kuti, Julia; Brown, Jessica; Mahon, Jessica R; Gayda-Chelder, Christine

    2016-12-01

    The reliable measurement of brain health and cognitive function is essential in mitigating the negative effects associated with cognitive decline through early and accurate diagnosis of change. The present research explored the relationship between EEG coherence for electrodes within frontal and posterior regions, as well as coherence between frontal and posterior electrodes and performance on standard neuropsychological measures of memory and executive function. EEG coherence for eyes-closed resting-state EEG activity was calculated for delta, theta, alpha, beta, and gamma frequency bands. Participants (N=66; mean age=67.15years) had their resting-state EEGs recorded and completed a neuropsychological battery that assessed memory and executive function, two cognitive domains that are significantly affected during aging. A positive relationship was observed between coherence within the frontal region and performance on measures of memory and executive function for delta and beta frequency bands. In addition, an inverse relationship was observed for coherence between frontal and posterior electrode pairs, particularly within the theta frequency band, and performance on Digit Span Sequencing, a measure of working memory. The present research supports a more substantial link between EEG coherence, rather than spectral power, and cognitive function. Continued study in this area may enable EEG to be applied broadly as a diagnostic measure of cognitive ability.

  1. Conservative management of posterior ankle impingement: a case report

    PubMed Central

    Senécal, Isabelle; Richer, Nadia

    2016-01-01

    Objective: To describe the pain and functional improvements of a patient with posterior ankle impingement following a treatment plan incorporating soft tissue therapy, chiropractic adjustment and a progressive rehabilitation program. Clinical Features: A 37-year- old male presented with posterolateral ankle pain exacerbated by plantar flexion two weeks after sustaining an inversion ankle sprain. Oedema was present and the patient was describing a sensation of instability while walking. The initial diagnosis of lateral ankle sprain was found to be complicated by a posterior ankle impingement caused by a tenosynovitis of the flexor hallucis longus sheath suspected during the physical examination and confirmed by MRI. Intervention and Outcome: The patient was treated over a 14-week period. Soft tissue therapy, a rehabilitation program and cortisone injection were used to treat this condition. A precise description of the rehabilitation program that contains open kinetic chain, closed kinetic chain, proprioception, and conditioning exercises prescribed to the patient is given. After the treatment plan, the patient returned to play pain free and had no daily living restrictions. Summary: A protocol including rest, soft tissue therapy, open and closed kinetic chain exercises, sport-specific exercises and cortisone injection appeared to facilitate complete recovery of this patient’s posterior ankle impingement. PMID:27385836

  2. Evidence for extra radiation? Profile likelihood versus Bayesian posterior

    SciTech Connect

    Hamann, Jan

    2012-03-01

    A number of recent analyses of cosmological data have reported hints for the presence of extra radiation beyond the standard model expectation. In order to test the robustness of these claims under different methods of constructing parameter constraints, we perform a Bayesian posterior-based and a likelihood profile-based analysis of current data. We confirm the presence of a slight discrepancy between posterior- and profile-based constraints, with the marginalised posterior preferring higher values of the effective number of neutrino species N{sub eff}. This can be traced back to a volume effect occurring during the marginalisation process, and we demonstrate that the effect is related to the fact that cosmic microwave background (CMB) data constrain N{sub eff} only indirectly via the redshift of matter-radiation equality. Once present CMB data are combined with external information about, e.g., the Hubble parameter, the difference between the methods becomes small compared to the uncertainty of N{sub eff}. We conclude that the preference of precision cosmological data for excess radiation is 'real' and not an artifact of a specific choice of credible/confidence interval construction.

  3. Bacillus Panophthalmitis with Posterior Extension to the Prechiasmatic Optic Nerve

    PubMed Central

    Notz, Gregory M.

    2016-01-01

    A rare case of Bacillus panophthlamitis with extension to the prechiasmatic optic nerve secondary to hematogenous spreading after intravenous drug use is presented. A 27-year-old man with a recent history of trauma to the left eye presented with severe left eye pain following a binge of intravenous drug use. Visual acuity (VA) was LP. On examination he had chemosis, proptosis, elevated intraocular pressure, and a complete hyphema. CT-scan identified preseptal swelling, but no evidence of any posterior extension of the anterior process or orbital fractures. Topical and systemic therapy were initiated. On follow-up clinical examination less than 12 hours after presentation he had signs of a keratitis with worsening ophthalmoplegia and repeat imaging demonstrated posterior extension to the prechiasmatic optic nerve. Shortly after the cornea ruptured with cultures growing Bacillus. The patient underwent enucleation and has had no further progression of infection. To the best of our knowledge, this is the first report of Bacillus panophthalmitis presenting with signs of trauma with posterior extension to the prechiasmatic optic nerve. PMID:27994900

  4. Surgical management of unruptured posterior carotid artery wall aneurysms.

    PubMed

    O'Shaughnessy, Brian A; Getch, Christopher C; Bendok, Bernard R; Batjer, H Hunt

    2003-07-15

    Intracranial aneurysms arising from the posterior wall of the supraclinoid carotid artery are extremely common lesions. The aneurysm dilation typically occurs in immediate proximity to the origin of the posterior communicating artery and, less commonly, the anterior choroidal artery (AChA). Because of the increasingly widespread use of noninvasive neuroimaging methods to evaluate patients believed to harbor cerebral lesions, many of these carotid artery aneurysms are now documented in their unruptured state, prior to occurrence of subarachnoid hemorrhage. Based on these factors, the management of unruptured posterior carotid artery (PCA) wall aneurysms is an important element of any neurosurgical practice. Despite impressive recent advances in endovascular therapy, the placement of microsurgical clips to exclude aneurysms with preservation of all afferent and efferent vasculature remains the most efficacious and durable therapy. To date, an optimal outcome is only achieved when the neurosurgeon is able to combine systematic preoperative neurovascular assessment with meticulous operative technique. In this report, the authors review their surgical approach to PCA wall aneurysms, which is greatly based on the extensive neurovascular experience of the senior author. Focus is placed on their methods of preoperative evaluation and operative technique, with emphasis on neurovascular anatomy and the significance of oculomotor nerve compression. They conclude by discussing surgery-related complications, with a particular focus on intraoperative rupture of aneurysms and their management, and the postoperative ischemic AChA syndrome.

  5. Posterior reversible encephalopathy syndrome in children: a case series

    PubMed Central

    Emeksiz, Serhat; Kutlu, Nurettin Onur; Çaksen, Hüseyin; Alkan, Gülsüm; Yıkmaz, Hülya Şeker; Tokgöz, Hüseyin

    2016-01-01

    Posterior reversible encephalopathy syndrome is characterized by hypertension, seizure, headache, clouding of consciousness, and visual disturbance, and is diagnosed in the presence of typical lesions on magnetic resonance imaging. We retrospectively evaluated five patients who were diagnosed as having posterior reversible encephalopathy syndrome and followed up in Meram Medical Faculty, Pediatric Intensive Care and Hematology wards, between January 2010 and January 2014. We reviewed the demographic and clinical data, and neuroimaging findings. The primary diseases of the subjects included acute lymphocytic leukemia (n=2), Henoch-Schönlein purpura (n=1), systemic lupus erythematous (n=1), and acute poststreptococcal glomerulonephritis (n=1). The mean age was 10±4.58 years (range, 5–14 years). Acute elevation of blood pressure was found in all patients (n=5). Initial neurologic manifestations included seizure, clouding of consciousness, headache, and visual disturbance. After the diagnosis was made through clinical evaluations and magnetic resonance imaging, complete clinical recovery was obtained in all patients with the appropriate therapeutic approach. In conclusion, posterior reversible encephalopathy syndrome should be considered in the differential diagnosis of patients who present with encephalopathy and underlying diseases such as nephritis, vasculitis, malignancy accompanied by hypertension, and a history of use of medication. PMID:28123335

  6. [Kocher-Langenbeck approach in the surgical management of posterior wall fractures of the acetabulum].

    PubMed

    Fernández-Palomo, L J

    2016-01-01

    Surgical treatment of acetabular fractures is indicated in displaced cases in order to restore and stabilize the hip joint and the pelvic ring integrity. Posterior structure fractures must be treated through posterior pelvic surgical approaches. The Kocher-Langenbeck is the most recommended approach for the majority of posterior acetabular fractures.

  7. Arthroscopic posterior cruciate ligament reconstruction with allograft versus autograft

    PubMed Central

    Sun, Xiujiang; Zhang, Jianfeng; Qu, Xiaoyi

    2015-01-01

    Introduction The aim of the study was to compare and analyze retrospectively the outcomes of arthroscopic posterior cruciate ligament reconstruction with autograft versus allograft. Material and methods Seventy-one patients who underwent arthroscopic posterior cruciate ligament reconstruction with an autograft or allograft met our inclusion criteria. There were 36 patients in the autograft group and 35 patients in the allograft group. All the patients were evaluated by physical examination and a functional ligament test. Comparative analysis was done in terms of operation time, incision length, fever time, postoperative infection rate, incidence of numbness and dysesthesia around the incision, as well as a routine blood test. Results The average follow-up of the autograft group was 3.2 ±0.2 years and that of the allograft group was 3.3 ±0.6 years; there was no significant difference (p > 0.05). No differences existed in knee range of motion, Lysholm scores, International Knee Documentation Committee standard evaluation form and Tegner activity score at final follow-up (p > 0.05), except that patients in the allograft group had a shorter operation time and incision length and a longer fever time (p < 0.05). We found a difference in posterior drawer test and KT-2000 arthrometer assessment (p < 0.05). The posterior tibia displacement averaged 3.8 ±1.5 mm in the autograft group and 4.8 ±1.7 mm in the allograft group (p < 0.05). The incidence of numbness and dysesthesia around the incision in the autograft group was higher than that in the allograft group (p < 0.05). There was no infection postoperatively. The white blood cells and neutrophils in the allograft group increased more than those in the autograft group postoperatively (p < 0.05). Conclusions Both groups of patients had satisfactory outcomes after the operation. However, in the instrumented posterior laxity test, the autograft gave better results than the allograft. No differences in functional scores

  8. Factors predicting surgical site infection after posterior lumbar surgery

    PubMed Central

    Wang, Tao; Wang, Hui; Yang, Da-Long; Jiang, Li-Qiang; Zhang, Li-Jun; Ding, Wen-Yuan

    2017-01-01

    Abstract This is a retrospective study. The purpose of this study is to explore incidence and risk factors for surgical site infection (SSI) after posterior lumbar surgery. SSI is a common complication after posterior lumbar surgery, bringing mental and physical pain and prolonging hospital stay. However, predisposing factors, as reported less, remain controversial. Patients who underwent posterior lumbar surgery at 3 centers between 2006 and 2016 were included. The possible factors include 3 aspects: demographic variables-age, sex, body mass index (BMI), waist-to-hip radio (WHR), hypertension, diabetes, heart disease, smoking, drinking, steroidal injection, surgical time between June and September, preoperative shower; blood test variables-white blood cell (WBC), neutrophil, red blood cell (RBC), hemoglobin (Hb), total protein (TP), albumin, albumin/globulin (A/G), C-reactive protein (CRP), procalcitonin (PCT), erythrocyte sedimentation rate (ESR) and surgical related variables-operation time, blood loss, operative level, instrumentation, incision length. Factors related with SSI were also performed by multivariate analysis. The prevalence of SSI was 3.00% (267 cases of 8879) had a postoperative wound infection. There were significant difference in WHR (0.92 vs 0.83), WBC (4.31 vs 6.69), TP (58.7 vs 65.2), albumin (36.9 vs 43.2), CRP (2.01 vs 0.57), PCT (0.097 vs 0.067), operation time (217.9 vs 195.7), blood loss (997.1 vs 915.3) and operative level (3.05 vs 2.45) and incision length (24.1 vs 20.0) between SSI group and non-SSI group. >60 years old, female, BMI <18.5 and >30.0, diabetes, male smoking, preoperative steroidal injection, surgical time between June and September, no preoperative shower, instrumentation surgery were risk factors for SSI after posterior lumbar surgery. Many factors, >60 years old, female, BMI, WHR, diabetes, male smoking, preoperative steroidal injection, surgical time between June and September, preoperative shower, WBC, TP, albumin

  9. Vascular Complications in Arthroscopic Repair Of Posterior Cruciate Ligament

    PubMed Central

    Agotegaray, Juan Ignacio; Comba, Ignacio; Bisiach, Luciana; Grignaffini, María Emilia

    2017-01-01

    Introduction: Posterior cruciate ligament is the primary stabilizer of the knee. Among the potential complications in arthroscopic repair of this ligament, there are vascular lesions, due to laceration, thrombosis and injury of the intima of the popliteal artery. We used one case to show the vascular complications that may arise in arthroscopic repair of the posterior cruciate ligament, how to handle it and the results. Methods: One patient, 33 years old, with a history of traffic accident. In a physical exam the patient shows pain and swelling of the knee, positive posterior drawer test and positive Godfrey test. X-rays on the knee show posterior tibial translation and MRI a complete fibers rupture at the middle third of the posterior cruciate ligament. An arthroscopic repair surgery was scheduled three weeks after trauma, with PCL reconstruction using simple band technique.After surgical intervention, hemostatic cuff was released, no peripheral pulse, paleness and coldness of the member was confirmed. An arteriography was carried out, which confirmed absences of distal vascular filling in the popliteal artery. An urgent referral was carried out with Vascular Surgery Services, who had been informed of the surgery previously (a notification that is part of our routine for this kind of interventions). Arteriorrhaphy and venorrhaphy of the popliteal arteries was fulfilled 12 hours later, with a leg fasciotomy. Daily monitoring was performed, and after 72 hours, muscle necrosis is seen with wound drainage, analysis shows presence of gram-negative bacilli, Proteus Mirabilis-Pseudomonas spp and the lab results showed leukocytes: 8.700/ml, ESR: 58, CRP: 48. A new surgery is performed with complete resection of the anterior external compartment of the leg, and a system of continuous cleansing is applied with physiological saline solution and boric acid for 14 days until drainage is eliminated. Vancomycin and ceftazidime EV was indicated for 14 days and, after a good

  10. POSTERIOR INTERBONE ARTERY FLAP FOR COVERING SERIOUS FOREARM, WRIST AND HAND INJURIES

    PubMed Central

    de Lima, Sérgio José; Domingos da Costa, Ricardo Pereira; de Oliveira, Emanoel; Prudente, Fabrício Guimarães; Mendonça, Marcelo Paris; Soares de Camargo, Christiano

    2015-01-01

    To assess the results achieved with posterior interbone artery flap covering serious injuries of the distal third of the forearm, wrist and hand, evaluating the degree of effectiveness of this procedure. Methods: 35 patients with serious injuries of the distal third of upper limbs were studied. We assessed the kind of trauma, injury site, flap size, skin coverage need, clinical outcome and complications. Results: The most frequent mechanism of trauma was motorcycle accident. The most commonly affected regions were: dorsal hand, wrist volar regions and the first commissure. In all patients, the flap size was enough to cover key tissues exposed by the injury. The donor area did not show complications, being primarily closed in 23 cases. The outcomes were good for 31 cases. In 22 patients, no complication was found, and the flap was completely lost in four. Conclusion: Posterior interbone artery flap provides good outcomes in covering serious injuries of the distal third of upper limbs, leading to a stable and reliable coverage, not compromising key irrigating arteries of the hand, enabling the performance of reconstruction procedures. Therefore, this is a useful alternative in such cases. PMID:26998451

  11. Load-bearing evaluation of spinal posterior column by measuring surface strain from lumbar pedicles. An in vitro study.

    PubMed

    Sun, Peidong; Zhao, Weidong; Bi, Zhenyu; Wu, Changfu; Ouyang, Jun

    2012-01-01

    An understanding of the load transfer within spinal posterior column of lumbar spine is necessary to determine the influence of mechanical factors on potential mechanisms of the motion-sparing implant such as artificial intervertebral disc and the dynamic spine stabilization systems. In this study, a new method has been developed for evaluating the load bearing of spinal posterior column by the surface strain of spinal pedicle response to the loading of spinal segment. Six cadaveric lumbar spine segments were biomechanically evaluated between levels L1 and L5 in intact condition and the strain gauges were pasted to an inferior surface of L2 pedicles. Multidirectional flexibility testing used the Panjabi testing protocol; pure moments for the intact condition with overall spinal motion and unconstrained intact moments of ±8 Nm were used for flexion-extension and lateral bending testing. High correlation coefficient (0.967-0.998) indicated a good agreement between the load of spinal segment and the surface strain of pedicle in all loading directions. Principal compressive strain could be observed in flexion direction and tensile strain in extension direction, respectively. In conclusion, the new method seems to be effective for evaluating posterior spinal column loads using pedicles' surface strain data collected during biomechanical testing of spine segments.

  12. Sleep apnoea adversely affects the outcome in patients who undergo posterior lumbar fusion: a population-based study.

    PubMed

    Stundner, O; Chiu, Y-L; Sun, X; Ramachandran, S-K; Gerner, P; Vougioukas, V; Mazumdar, M; Memtsoudis, S G

    2014-02-01

    Despite the increasing prevalence of sleep apnoea, little information is available regarding its impact on the peri-operative outcome of patients undergoing posterior lumbar fusion. Using a national database, patients who underwent lumbar fusion between 2006 and 2010 were identified, sub-grouped by diagnosis of sleep apnoea and compared. The impact of sleep apnoea on various outcome measures was assessed by regression analysis. The records of 84,655 patients undergoing posterior lumbar fusion were identified and 7.28% (n = 6163) also had a diagnostic code for sleep apnoea. Compared with patients without sleep apnoea, these patients were older, more frequently female, had a higher comorbidity burden and higher rates of peri-operative complications, post-operative mechanical ventilation, blood product transfusion and intensive care. Patients with sleep apnoea also had longer and more costly periods of hospitalisation. In the regression analysis, sleep apnoea emerged as an independent risk factor for the development of peri-operative complications (odds ratio (OR) 1.50, confidence interval (CI) 1.38;1.62), blood product transfusions (OR 1.12, CI 1.03;1.23), mechanical ventilation (OR 6.97, CI 5.90;8.23), critical care services (OR 1.86, CI 1.71;2.03), prolonged hospitalisation and increased cost (OR 1.28, CI 1.19;1.37; OR 1.10, CI 1.03;1.18). Patients with sleep apnoea who undergo posterior lumbar fusion pose significant challenges to clinicians.

  13. Lack of the murine homeobox gene Hesx1 leads to a posterior transformation of the anterior forebrain

    PubMed Central

    Andoniadou, Cynthia L.; Signore, Massimo; Sajedi, Ezat; Gaston-Massuet, Carles; Kelberman, Daniel; Burns, Alan J.; Itasaki, Nobue; Dattani, Mehul; Martinez-Barbera, Juan Pedro

    2008-01-01

    The homeobox gene Hesx1 is an essential repressor that is required within the anterior neural plate for normal forebrain development in mouse and humans. Combining genetic cell labelling and marker analyses, we demonstrate that the absence of Hesx1 leads to a posterior transformation of the anterior forebrain (AFB) during mouse development. Our data suggest that the mechanism underlying this transformation is the ectopic activation of Wnt/β-catenin signalling within the Hesx1 expression domain in the AFB. When ectopically expressed in the developing mouse embryo, Hesx1 alone cannot alter the normal fate of posterior neural tissue. However, conditional expression of Hesx1 within the AFB can rescue the forebrain defects observed in the Hesx1 mutants. The results presented here provide new insights into the function of Hesx1 in forebrain formation. PMID:17360769

  14. Latrophilin Signaling Links Anterior-Posterior Tissue Polarity and Oriented Cell Divisions in the C. elegans Embryo

    PubMed Central

    Langenhan, Tobias; Prömel, Simone; Mestek, Lamia; Esmaeili, Behrooz; Waller-Evans, Helen; Hennig, Christian; Kohara, Yuji; Avery, Leon; Vakonakis, Ioannis; Schnabel, Ralf; Russ, Andreas P.

    2010-01-01

    SUMMARY Understanding the mechanisms that coordinate the orientation of cell division planes during embryogenesis and morphogenesis is a fundamental problem in developmental biology. Here we show that the orphan receptor lat-1, a homolog of vertebrate latrophilins, plays an essential role in the establishment of tissue polarity in the C. elegans embryo. We provide evidence that lat-1 is required for the alignment of cell division planes to the anterior-posterior axis and acts in parallel to known polarity and morphogenesis signals. lat-1 is a member of the Adhesion-GPCR protein family and is structurally related to flamingo/CELSR, an essential component of the planar cell polarity pathway. We dissect the molecular requirements of lat-1 signaling and implicate lat-1 in an anterior-posterior tissue polarity pathway in the pre-morphogenesis stage of C. elegans development. PMID:19853563

  15. A LIM-homeobox gene is required for differentiation of Wnt-expressing cells at the posterior end of the planarian body.

    PubMed

    Hayashi, Tetsutaro; Motoishi, Minako; Yazawa, Shigenobu; Itomi, Kazu; Tanegashima, Chiharu; Nishimura, Osamu; Agata, Kiyokazu; Tarui, Hiroshi

    2011-09-01

    Planarians have high regenerative ability, which is dependent on pluripotent adult somatic stem cells called neoblasts. Recently, canonical Wnt/β-catenin signaling was shown to be required for posterior specification, and Hedgehog signaling was shown to control anterior-posterior polarity via activation of the Djwnt1/P-1 gene at the posterior end of planarians. Thus, various signaling molecules play an important role in planarian stem cell regulation. However, the molecular mechanisms directly involved in stem cell differentiation have remained unclear. Here, we demonstrate that one of the planarian LIM-homeobox genes, Djislet, is required for the differentiation of Djwnt1/P-1-expressing cells from stem cells at the posterior end. RNA interference (RNAi)-treated planarians of Djislet [Djislet(RNAi)] show a tail-less phenotype. Thus, we speculated that Djislet might be involved in activation of the Wnt signaling pathway in the posterior blastema. When we carefully examined the expression pattern of Djwnt1/P-1 by quantitative real-time PCR during posterior regeneration, we found two phases of Djwnt1/P-1 expression: the first phase was detected in the differentiated cells in the old tissue in the early stage of regeneration and then a second phase was observed in the cells derived from stem cells in the posterior blastema. Interestingly, Djislet is expressed in stem cell-derived DjPiwiA- and Djwnt1/P-1-expressing cells, and Djislet(RNAi) only perturbed the second phase. Thus, we propose that Djislet might act to trigger the differentiation of cells expressing Djwnt1/P-1 from stem cells.

  16. Posterior femoral condylar offset after total knee replacement in the risk of knee flexion contracture.

    PubMed

    Onodera, Tomohiro; Majima, Tokifumi; Nishiike, Osamu; Kasahara, Yasuhiko; Takahashi, Daisuke

    2013-08-01

    The aim of this study was to clarify the risk of knee flexion contracture associated with a posterior femoral condylar offset after total knee replacement (TKR). Radiographs from 100 healthy Japanese volunteers were included in the study. We evaluated femoral component posterior offset in various implants and compared them with the normal Japanese knee. Posterior offset of the femoral condyle is up to a maximum of 4.7 times greater than that of the healthy Japanese knee in all knee implants. Excess posterior offset of the femoral condyle in TKR prostheses may cause knee joint flexion contracture due to the relative shortening of the posterior soft tissue.

  17. Posterior patterning by the Caenorhabditis elegans even-skipped homolog vab-7.

    PubMed

    Ahringer, J

    1996-05-01

    Patterning of the posterior end in animals is not well understood. Homologs of Drosophila even-skipped (eve) have a similar posterior expression pattern in many animals, and in vertebrates they are linked physically to the "posterior" ends of homeotic clusters (HOM-C), suggesting a conserved role in posterior development. However, the function of this posterior expression is not known. Here I show that the Caenorhabditis elegans gene vab-7 encodes an eve homolog that is required for posterior development and expressed in a pattern strikingly similar to that of vertebrate eve genes. Using a four-dimensional recording system, I found that posterior body muscles and the posterior epidermis are patterned abnormally in vab-7 mutants, but commitment to muscle and epidermal fates is normal. Furthermore, vab-7 activity is required for the complete expression of the most posterior HOM-C gene egl-5 in muscle cells, supporting the idea that eve homologs may act with the HOM-C to determine posterior cell fates. The conservation of sequence and expression pattern between vab-7 and eve homologs in other animals argues that most eve genes have posterior mesodermal and ectodermal patterning functions.

  18. Posterior compartment defect repair in vaginal surgery: update on surgical techniques.

    PubMed

    Ginger, Van Anh T; Kobashi, Kathleen C

    2007-09-01

    Posterior colporrhaphy has been the most common surgical technique for the repair of posterior compartment defects. Traditional posterior colporrhaphy involves plication of the levator ani, which may result in dyspareunia related to narrowing of the introitus. Current posterior compartment repairs either plicate the midline fascia or repair the specific site of fascial weakness. Despite insubstantial data, the use of grafts to reinforce posterior repairs has gained popularity. Grafts such as allografts, xenografts, and synthetic meshes have been used to reinforce the posterior wall. Complications include infection and erosion, as well as recurrence of prolapse. Minimally invasive techniques have been developed to recreate the apical support of the vaginal vault and repair the posterior prolapse. Properly conducted randomized prospective trials are needed to adequately assess these new approaches.

  19. Posterior shoulder instability following anatomic total shoulder arthroplasty: A case report and review of management

    PubMed Central

    Galvin, Joseph W.; Eichinger, Josef K.; Boykin, Robert E.; Szöllösy, Gregor; Lafosse, Laurent

    2015-01-01

    We report a case of posterior shoulder instability following anatomic total shoulder arthroplasty (TSA). In addition, we present guidelines to aid in the management of posterior instability after TSA. A 50-year-old male underwent anatomic TSA for glenohumeral osteoarthritis. Postoperatively, the patient developed posterior instability secondary to glenoid retroversion. He did not improve despite conservative treatment. He underwent an arthroscopic posterior bone block procedure, 4-month after his index arthroplasty. At 14-month follow-up, the patient had regained near full motion and strength, and radiographs demonstrated osseous integration with no evidence of component loosening. Posterior instability following TSA is a relatively rare complication and challenging to manage. The posterior, arthroscopic iliac crest bone block grafting procedure represents a treatment option for posterior instability in the setting of a stable glenoid prosthesis following TSA. PMID:26622130

  20. Patterns of attachment of the myodural bridge by the rectus capitis posterior minor muscle.

    PubMed

    Yuan, Xiao-Ying; Yu, Sheng-Bo; Li, Yun-Fei; Chi, Yan-Yan; Zheng, Nan; Gao, Hai-Bin; Luan, Bing-Yi; Zhang, Zhao-Xi; Sui, Hong-Jin

    2016-03-01

    The myodural bridge was first described by Hack in 1995 and was thought to be related to chronic cervicogenic headaches. For a long time, few studies revealed the patterns of the myodural bridge considering the rectus capitis posterior minor muscle. In this study, P45 plastination technology and anatomical dissection were performed on head specimens, and four different terminal region types of the rectus capitis posterior minor muscle were observed, including the posterior atlanto-occipital interspace, posterior arch of the atlas and posterior atlanto-axial interspace. We propose that the myodural complex structures in the posterior atlanto-occipital and posterior atlanto-axial interspace have cooperative effects on cerebrospinal fluid and work together. This force might be an important source for the circulation of cerebrospinal fluid.

  1. Human posterior auditory cortex gates novel sounds to consciousness

    PubMed Central

    Jääskeläinen, Iiro P.; Ahveninen, Jyrki; Bonmassar, Giorgio; Dale, Anders M.; Ilmoniemi, Risto J.; Levänen, Sari; Lin, Fa-Hsuan; May, Patrick; Melcher, Jennifer; Stufflebeam, Steven; Tiitinen, Hannu; Belliveau, John W.

    2004-01-01

    Life or death in hostile environments depends crucially on one's ability to detect and gate novel sounds to awareness, such as that of a twig cracking under the paw of a stalking predator in a noisy jungle. Two distinct auditory cortex processes have been thought to underlie this phenomenon: (i) attenuation of the so-called N1 response with repeated stimulation and (ii) elicitation of a mismatch negativity response (MMN) by changes in repetitive aspects of auditory stimulation. This division has been based on previous studies suggesting that, unlike for the N1, repetitive “standard” stimuli preceding a physically different “novel” stimulus constitute a prerequisite to MMN elicitation, and that the source loci of MMN and N1 are different. Contradicting these findings, our combined electromagnetic, hemodynamic, and psychophysical data indicate that the MMN is generated as a result of differential adaptation of anterior and posterior auditory cortex N1 sources by preceding auditory stimulation. Early (≈85 ms) neural activity within posterior auditory cortex is adapted as sound novelty decreases. This alters the center of gravity of electromagnetic N1 source activity, creating an illusory difference between N1 and MMN source loci when estimated by using equivalent current dipole fits. Further, our electroencephalography data show a robust MMN after a single standard event when the interval between two consecutive novel sounds is kept invariant. Our converging findings suggest that transient adaptation of feature-specific neurons within human posterior auditory cortex filters superfluous sounds from entering one's awareness. PMID:15096618

  2. Multiple cytosolic calcium buffers in posterior pituitary nerve terminals.

    PubMed

    McMahon, Shane M; Chang, Che-Wei; Jackson, Meyer B

    2016-03-01

    Cytosolic Ca(2+) buffers bind to a large fraction of Ca(2+) as it enters a cell, shaping Ca(2+) signals both spatially and temporally. In this way, cytosolic Ca(2+) buffers regulate excitation-secretion coupling and short-term plasticity of release. The posterior pituitary is composed of peptidergic nerve terminals, which release oxytocin and vasopressin in response to Ca(2+) entry. Secretion of these hormones exhibits a complex dependence on the frequency and pattern of electrical activity, and the role of cytosolic Ca(2+) buffers in controlling pituitary Ca(2+) signaling is poorly understood. Here, cytosolic Ca(2+) buffers were studied with two-photon imaging in patch-clamped nerve terminals of the rat posterior pituitary. Fluorescence of the Ca(2+) indicator fluo-8 revealed stepwise increases in free Ca(2+) after a series of brief depolarizing pulses in rapid succession. These Ca(2+) increments grew larger as free Ca(2+) rose to saturate the cytosolic buffers and reduce the availability of Ca(2+) binding sites. These titration data revealed two endogenous buffers. All nerve terminals contained a buffer with a Kd of 1.5-4.7 µM, and approximately half contained an additional higher-affinity buffer with a Kd of 340 nM. Western blots identified calretinin and calbindin D28K in the posterior pituitary, and their in vitro binding properties correspond well with our fluorometric analysis. The high-affinity buffer washed out, but at a rate much slower than expected from diffusion; washout of the low-affinity buffer could not be detected. This work has revealed the functional impact of cytosolic Ca(2+) buffers in situ in nerve terminals at a new level of detail. The saturation of these cytosolic buffers will amplify Ca(2+) signals and may contribute to use-dependent facilitation of release. A difference in the buffer compositions of oxytocin and vasopressin nerve terminals could contribute to the differences in release plasticity of these two hormones.

  3. Minimally invasive tubular access for posterior cervical foraminotomy

    PubMed Central

    Branch, Byron C.; Hilton, Donald L.; Watts, Clark

    2015-01-01

    Background: Minimally invasive tubular access for posterior cervical foraminotomy can be an effective and safe technique for decompression of the nerve root utilizing minimally invasive muscle splitting with routine outpatient discharge. This technique has come under scrutiny calling into question the associated learning curve, a subjective limited exposure provided, and an argument that the risks and complications are largely unknown. In response to previously published critiques, this study aims to describe the outcomes and complications associated with this technique in a large patient series. Methods: A retrospective chart review was performed from 1999 to 2013 capturing a single surgeon's experience with the minimally invasive tubular access for posterior cervical foraminotomy technique from a single institution, encompassing 463 patients. Surgical outcome documented at follow-up and complications were obtained from this patient series. Additional variables analyzed include: Hospital length of stay, number of levels operated, targeted root for decompression, side operated, length of surgery, and estimated blood loss. Results: Outpatient discharge was achieved in 91.6% of cases. There were 10 complications (2.2%) among the 463 patients undergoing this technique from 1999 to 2013. Patients were followed for an average of 1 year and 2 months postoperatively. Improvement from the preoperative condition was observed in 98.2% of patients and excellent outcomes with patients reporting complete relief of symptoms with no or mild residual discomfort was seen in 92.2%. Conclusions: Compared with open techniques, minimally invasive tubular access for posterior cervical foraminotomy demonstrates comparable, if not superior, complication rates, and patient outcomes. PMID:26009705

  4. Posterior dental size reduction in hominids: the Atapuerca evidence.

    PubMed

    Bermúdez de Castro, J M; Nicolas, M E

    1995-04-01

    In order to reassess previous hypotheses concerning dental size reduction of the posterior teeth during Pleistocene human evolution, current fossil dental evidence is examined. This evidence includes the large sample of hominid teeth found in recent excavations (1984-1993) in the Sima de los Huesos Middle Pleistocene cave site of the Sierra de Atapuerca (Burgos, Spain). The lower fourth premolars and molars of the Atapuerca hominids, probably older than 300 Kyr, have dimensions similar to those of modern humans. Further, these hominids share the derived state of other features of the posterior teeth with modern humans, such as a similar relative molar size and frequent absence of the hypoconulid, thus suggesting a possible case of parallelism. We believe that dietary changes allowed size reduction of the posterior teeth during the Middle Pleistocene, and the present evidence suggests that the selective pressures that operated on the size variability of these teeth were less restrictive than what is assumed by previous models of dental reduction. Thus, the causal relationship between tooth size decrease and changes in food-preparation techniques during the Pleistocene should be reconsidered. Moreover, the present evidence indicates that the differential reduction of the molars cannot be explained in terms of restriction of available growth space. The molar crown area measurements of a modern human sample were also investigated. The results of this study, as well as previous similar analyses, suggest that a decrease of the rate of cell proliferation, which affected the later-forming crown regions to a greater extent, may be the biological process responsible for the general and differential dental size reduction that occurred during human evolution.

  5. Posterior Lumbar Interbody Fusion via a Unilateral Approach

    PubMed Central

    Shin, Hyun Chul; Yi, Seong; Kim, Sang Hyun; Yoon, Do Heum

    2006-01-01

    This study sought to determine the outcomes of posterior lumbar interbody fusion (PLIF), via a unilateral approach, in selected patients who presented with unilateral leg pain and segmental instability of the lumbar spine. Patients with a single level of a herniated disc disease in the lumbar spine, unilateral leg pain, chronic disabling lower back pain (LBP), and a failed conservative treatment, were considered for the procedure. A total of 41 patients underwent a single-level PLIF using two PEEK™ (Poly-Ether-Ether-Ketone) cages filled with iliac bone, via a unilateral approach. The patients comprised 21 women and 20 men with a mean age of 41 years (range: 22 to 63 years). Two cages were inserted using a unilateral medial facetectomy and a partial hemilaminectomy. At follow-up, the outcomes were assessed using the Prolo Scale. The success of the fusion was determined by dynamic lumbar radiography and/or computerized tomography scanning. All the patients safely underwent surgery without severe complications. During a mean follow-up period of 26 months, 1 patient underwent percutaneous pedicle screw fixation due to persistent LBP. A posterior displacement of the cage was found in one patient. At the last follow up, 90% of the patients demonstrated satisfactory results. An osseous fusion was present in 85% of the patients. A PLIF, via a unilateral approach, enables a solid union with satisfactory clinical results. This preserves part of the posterior elements of the lumbar spine in selected patients with single level instability and unilateral leg pain. PMID:16807980

  6. Management of Cerebrospinal Fluid Leak following Posterior Cranial Fossa Surgery

    PubMed Central

    Altaf, Imran; Vohra, Anjum Habib; Shams, Shahzad

    2016-01-01

    Objective: Cerebrospinal fluid leakage remains a significant cause of morbidity following posterior fossa surgery, and its treatment remains a difficult problem. The aim of the study was to propose a treatment algorithm for its management. Methods: A retrospective, single-center study was conducted on 147 patients who underwent elective posterior fossa surgery for a variety of diseases. Patients with post operative CSF leakage had either been treated initially with conservative measures including re-suturing of the wound, with CSF lumbar drainage to be employed in case the CSF leakage didn’t stop, or the initial intervention was the institution of CSF lumbar drainage simultaneously with conservative measures. VP (ventriculo-peritoneal) shunt was done in patients with gross hydrocephalus on postoperative CT brain. Results: There were 25 (17%) cases of CSF leakage, including 24 incisional CSF leaks and one case of CSF otorrhea. In eight patients with incisional CSF leakage treated initially with conservative measures including re-suturing of the wound, CSF leakage stopped in only two cases. CSF lumbar drainage instituted later on in six cases with persistent leakage stopped the CSF leakage. In fourteen patients managed initially with re-suturing of the wound and concomitant CSF lumbar drainage, CSF leakage settled in all the cases. Two patients with gross hydrocephalus on post operative CT were managed successfully with VP shunt. Re-suturing of the wound with concomitant CSF lumbar drainage was found to be significantly associated (p=0.003) with the stoppage of CSF leakage, and the settlement of meningitis (p= 0.014). Conclusion: Incisional CSF leaks after posterior fossa surgery should be managed with re-suturing of the wound and concomitant CSF lumbar drainage, instead of an initial trial of conservative therapy alone. PMID:28083041

  7. Evaluation of posterior clinoid process pneumatization by multidetector computed tomography.

    PubMed

    Burulday, Veysel; Akgül, Mehmet Hüseyin; Muluk, Nuray Bayar; Ozveren, Mehmet Faik; Kaya, Ahmet

    2016-10-21

    In the present study, we investigated the types and ratio of posterior clinoid process (PCP) pneumatization in paranasal sinus multidetector computed tomography (MDCT). Paranasal MDCT images of 541 subjects (227 males, 314 females), between 15 and 65 years old, were included into the study. Pneumatization of anterior clinoid process and pneumatization types (I, II, or III) were evaluated in the males and females. PCP pneumatization was detected in 20.7 % of the males and 11.5 % of the females. Right, left, and bilateral PCP pneumatizations were detected in 7.9, 5.7, and 7.0 % of the males and 2.9, 3.2, and 4.5 % of the females, respectively. PCP pneumatization of the males is significantly higher than the females. The most detected type of pneumatization was type I (61.2 %) for all groups. In right, left, and bilateral pneumatizations separately, type I pneumatization was the most detected pneumatization type with the ratio of the 70.4, 65.2, and 50.0 %, respectively. In males, type I (61.7 %), and similarly in females, type I (60.6 %) pneumatization were detected more. Type II and type III pneumatizations were detected in decreasing order in both groups. In younger subjects, pneumatization of posterior clinoid process was found as higher, and in older subjects, PCP pneumatization was found as lower. Sclerosis process related to the aging may be responsible for the lower pneumatization ratios in older subjects. Structure of the surrounding regions of PCP is important for surgical procedures related to cavernous sinus, basilar apex aneurysms, and mass lesions. Preoperative radiological examinations are useful for operative planning. Any anomalies to PCP can cause unnecessary injury to the neurovascular complex structure around the cavernous sinus or postclinoidectomy CSF fistulas. Posterior clinoidectomies should be avoided in patients with type III PCP pneumatization to prevent CSF fistulas.

  8. Characteristic clinical features associated with aggressive posterior retinopathy of prematurity.

    PubMed

    Ahn, Y J; Hong, K E; Yum, H R; Lee, J H; Kim, K S; Youn, Y A; Park, S H

    2017-02-24

    PurposeTo identify the risk factors for, and clinical features and treatment outcomes of aggressive posterior retinopathy of prematurity (APROP) in Korean infants.MethodsAmong 770 premature infants who underwent screening, 105 infants (198 eyes, 13.63%) received treatment for ROP. A total of 24 infants (48 eyes, 3.12%) developed APROP while 81 infants (150 eyes, 10.52%) developed non-APROP treatment-requiring type. The medical records of ROP-treated infants were reviewed retrospectively. The associated systemic and maternal risk factors were analyzed and anatomical outcomes were compared according to the severity of ROP and treatment modalities.ResultsThe mean gestational age and birth weight at birth in the APROP group were significantly lower than those in the non-APROP group (P=0.019, P<0.001, respectively). Infants who were born small for their GA developed APROP more frequently than non-APROP patients (P<0.001). Chorioamnionitis-positive infants also showed higher incidence rate of APROP (APROP vs non-APROP; P<0.001 and zone I APROP vs posterior zone II APROP; P=0.036, respectively). Infants with APROP required heavier laser treatment with a higher retreatment rate compared to infants with non-APROP. Favorable anatomical outcomes were achieved in 95.3% from treatment-requiring non-APROP group, 85.7% from zone I APROP and 84.6% from posterior zone II APROP group.ConclusionIntrauterine growth restriction and chorioamnionitis were associated with development of APROP. These findings suggest that perinatal maternal environment inhibiting normal retinal vascular growth in utero may contribute to increasing the risk of APROP in premature infants.Eye advance online publication, 24 February 2017; doi:10.1038/eye.2017.18.

  9. Robotic mitral valve repair for degenerative posterior leaflet prolapse

    PubMed Central

    Javadikasgari, Hoda; Suri, Rakesh M.; Tappuni, Bassman; Lowry, Ashley M.; Mihaljevic, Tomislav; Mick, Stephanie

    2017-01-01

    Background Robotic mitral valve (MV) repair is the least invasive surgical approach to the MV and provides unparalleled access to the valve. We sought to assess technical aspects and clinical outcomes of robotic MV repair for isolated posterior leaflet prolapse by examining the first 623 such cases performed in a tertiary care center. Methods We reviewed the first 623 patients (mean age 56±9.7 years) with isolated posterior leaflet prolapse who underwent robotic primary MV repair from 01/2006 to 11/2013. All procedures were performed via right chest access with femoral perfusion for cardiopulmonary bypass. Results MV repair was attempted in all patients; 622 (99.8%) underwent MV repair and only 1 (0.2%) converted to replacement. After an initial attempt at robotic MV repair, 8 (1.3%) patients were converted to sternotomy as a result of management of residual mitral regurgitation (n=3), bleeding (n=1), difficulties with surgical exposure (n=2), aortic valve injury (n=1), and aortic dissection (n=1). Intraoperative post-repair echocardiography confirmed that all patients left the operating room with MR graded as mild or less, and pre-discharge echocardiography confirmed mild or less MR in 573 (99.1%). There was no hospital death, sternal wound infection, or renal failure. Seven (1.1%) patients suffered a stroke, 11 (1.8%) patients underwent re-exploration for bleeding, and 111 (19%) experienced new-onset atrial fibrillation. The mean intensive care unit length of stay and hospital length of stay were 29±17 hours and 4.6±1.6 days, respectively. Conclusions At a large tertiary care referral center, robotic MV repair for posterior prolapse is associated with zero mortality, infrequent operative morbidity, and near 100% successful repair. The combination of a patient selection algorithm and increased experience improved clinical outcomes and procedural efficiency. PMID:28203538

  10. Multi-Electrode Array for Transcutaneous Lumbar Posterior Root Stimulation.

    PubMed

    Krenn, Matthias; Hofstoetter, Ursula S; Danner, Simon M; Minassian, Karen; Mayr, Winfried

    2015-10-01

    Interest in transcutaneous electrical stimulation of the lumbosacral spinal cord is increasing in human electrophysiological and clinical studies. The stimulation effects on lower limb muscles depend on the depolarization of segmentally organized posterior root afferents and, thus, the rostro-caudal stimulation site. In previous studies, selective stimulation was achieved by varying the positions of single self-adhesive electrodes over the thoracolumbar spine. Here, we developed a multi-electrode surface array consisting of 3 × 8 electrode pads and tested its stimulation-site specificity. The array was placed longitudinally over the spine covering the T10-L2 vertebrae. Two different hydrogel layer configurations were utilized: a single layer adhered to all electrode pads of the array and a configuration comprised of eight separate strips attached to the three transverse electrode pads of each level. Voltage measurements demonstrated that an effectively focused field distribution along the longitudinal extent of the array was not accomplished when using the single continuous hydrogel layer, and segmental selective stimulation of the posterior root afferents was not possible. The separate strips produced a focused electric field distribution at the rostro-caudal level of the electrode pads selected for stimulation. This configuration allowed for the preferential elicitation of posterior root-muscle reflexes in either the L2-L4 innervated quadriceps or the L5-S2 innervated triceps surae muscle groups. Such multi-electrode array for transcutaneous spinal cord stimulation shall allow for improved control of stimulation conditions in electrophysiological studies and time-dependent and site-specific stimulation patterns for neuromodulation applications.

  11. Treatment of Locked Posterior Shoulder Dislocation With Bone Defect.

    PubMed

    Khira, Yousuf M; Salama, Adel M

    2017-03-14

    Locked posterior shoulder dislocation is an uncommon condition and is associated with a reverse Hill-Sachs lesion in 50% of cases. The condition is likely to occur in cases of violent trauma, seizures, or electric shock. Unrecognized dislocation with humeral head fracture affects joint function and humeral head vascularity and may lead to chronic instability, osteonecrosis, and osteoarthritis. A group of 12 patients, including 10 men and 2 women, with neglected locked posterior shoulder dislocation with a reverse Hill-Sachs lesion were treated with the modified McLaughlin technique. The added bone graft from the iliac crest was impacted in the defect and fixed with screws. Mean follow-up was 30 months (range, 24-48 months). The range of forward flexion was 150˚ to 175˚ (average, 165˚), external rotation ranged from 60˚ to 80˚ (average, 75˚), internal rotation ranged from 40˚ to 60˚ (average, 50˚), and average abduction was 150˚ (range, 145˚-160˚). The modified University of California Los Angeles (UCLA) scoring system was used for postoperative clinical evaluation. Total UCLA scores immediately postoperatively ranged from 22 to 28 points (average, 26.5 points) and averaged 30 points (range, 28-33 points) at last follow-up. No recurrence of dislocation occurred during the follow-up period. Of the study patients, 10 returned to their previous job and 2 modified their manual work. The modified McLaughlin technique with added iliac crest bone graft to fill the defect and prevent humeral head deformity is a successful technique for the treatment of patients with chronic locked posterior shoulder dislocation. [Orthopedics. 201x; xx(x):xx-xx.].

  12. Large radiopaque lesion in the posterior mandible: A challenging case

    PubMed Central

    Sasirekha, B.; Mathew, Philips; Ganeshkumar, M.; Austin, Ravi David; Prabhu, Raj

    2016-01-01

    Radiopaque lesions of the jawbones are frequently encountered in dental radiographs. A variety of conditions such as chronic inflammation, soft tissue calcifications, fibrosseous lesions, odontogenic tumors, and bone neoplasms can manifest as radiopaque lesions on the jawbones. These radiopaque lesions are often difficult to distinguish from each other, hence making the formulation of differential diagnosis challenging. A thorough patient's history and clinical examination supplemented by appropriate investigations will enable the clinician in narrowing down the differential diagnosis and to identify the condition accurately. Presented here is a case of the large radiopaque lesion on posterior mandible surrounded by lytic areas in a 20-year-old male patient. PMID:27829771

  13. Current approach in the diagnosis and management of posterior uveitis

    PubMed Central

    Sudharshan, S; Ganesh, Sudha K; Biswas, Jyotrimay

    2010-01-01

    Posterior uveitic entities are varied entities that are infective or non-infective in etiology. They can affect the adjacent structures such as the retina, vitreous, optic nerve head and retinal blood vessels. Thorough clinical evaluation gives a clue to the diagnosis while ancillary investigations and laboratory tests assist in confirming the diagnosis. Newer evolving techniques in the investigations and management have increased the diagnostic yield. In case of diagnostic dilemma, intraocular fluid evaluation for polymerase chain testing for the genome and antibody testing against the causative agent provide greater diagnostic ability. PMID:20029144

  14. Consolidation of Complex Events via Reinstatement in Posterior Cingulate Cortex

    PubMed Central

    Keidel, James L.; Ing, Leslie P.; Horner, Aidan J.

    2015-01-01

    It is well-established that active rehearsal increases the efficacy of memory consolidation. It is also known that complex events are interpreted with reference to prior knowledge. However, comparatively little attention has been given to the neural underpinnings of these effects. In healthy adults humans, we investigated the impact of effortful, active rehearsal on memory for events by showing people several short video clips and then asking them to recall these clips, either aloud (Experiment 1) or silently while in an MRI scanner (Experiment 2). In both experiments, actively rehearsed clips were remembered in far greater detail than unrehearsed clips when tested a week later. In Experiment 1, highly similar descriptions of events were produced across retrieval trials, suggesting a degree of semanticization of the memories had taken place. In Experiment 2, spatial patterns of BOLD signal in medial temporal and posterior midline regions were correlated when encoding and rehearsing the same video. Moreover, the strength of this correlation in the posterior cingulate predicted the amount of information subsequently recalled. This is likely to reflect a strengthening of the representation of the video's content. We argue that these representations combine both new episodic information and stored semantic knowledge (or “schemas”). We therefore suggest that posterior midline structures aid consolidation by reinstating and strengthening the associations between episodic details and more generic schematic information. This leads to the creation of coherent memory representations of lifelike, complex events that are resistant to forgetting, but somewhat inflexible and semantic-like in nature. SIGNIFICANCE STATEMENT Memories are strengthened via consolidation. We investigated memory for lifelike events using video clips and showed that rehearsing their content dramatically boosts memory consolidation. Using MRI scanning, we measured patterns of brain activity while

  15. Neuralgic A