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Sample records for acute corneal hydrops

  1. Acute corneal hydrops in keratoconus

    PubMed Central

    Maharana, Prafulla K; Sharma, Namrata; Vajpayee, Rasik B

    2013-01-01

    Acute corneal hydrops is a condition characterized by stromal edema due to leakage of aqueous through a tear in descemet membrane. The patient presents with sudden onset decrease in vision, photophobia, and pain. Corneal thinning and ectasias combined with trivial trauma to the eye mostly by eye rubbing is considered as the underlying cause. With conservative approach self-resolution takes around 2 to 3 months. Surgical intervention is required in cases of non-resolution of corneal edema to avoid complications and for early visual rehabilitation. Intracameral injection of air or gas such as perflouropropane is the most common surgical procedure done. Recent investigative modality such as anterior segment optical coherence tomography is an extremely useful tool for diagnosis, surgical planning, and postoperative follow up. Resolution of hydrops may improve the contact lens tolerance and visual acuity but most cases require keratoplasty for visual rehabilitation. PMID:23925338

  2. Acute hydrops in the corneal ectasias: associated factors and outcomes.

    PubMed Central

    Grewal, S; Laibson, P R; Cohen, E J; Rapuano, C J

    1999-01-01

    PURPOSE: To identify factors associated with the development of hydrops and affecting its clinical outcome. METHODS: Chart review of all patients with acute hydrops seen by a referral cornea service during a 2.5-year period between June 1996 and December 1998. RESULTS: Twenty-one patients (22 eyes) with acute hydrops were seen. Nineteen patients had keratoconus, 2 had pellucid marginal degeneration, and 1 had keratoglobus. Twenty-one of 22 (95%) eyes had seasonal allergies and 20 of 22 (91%) eyes had allergy-associated eye-rubbing behavior. Six of 22 (27%) had a diagnosis of Down's syndrome. Six patients were able to identify a traumatic inciting event: vigorous eye rubbing in 4 and traumatic contact lens insertion in 2. The affected area ranged from 7% to 100% of the corneal surface area and was related to disease duration and final visual acuity. Proximity of the area of edema to the corneal limbus ranged from 0 to 2.3 mm and was also related to prognosis. Three serious complications were observed: a leak, an infectious keratitis, and an infectious keratitis and coincidental neovascular glaucoma. Various medical therapies did not differ significantly in their effect on outcome, and ultimately 4 (18%) of 22 patients underwent penetrating keratoplasty. Best-corrected visual acuity was equal to or better than prehydrops visual acuity in 5 of the 6 patients in whom prehydrops visual acuity was known, without corneal transplantation. CONCLUSIONS: Allergy and eye-rubbing appear to be important risk factors in the development of hydrops. Visual results are acceptable in some patients without surgery. Close observation allows for the early detection and treatment of complications such as perforation and infection. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 PMID:10703124

  3. Acute corneal hydrops in keratoconus: a national prospective study of incidence and management

    PubMed Central

    Barsam, A; Petrushkin, H; Brennan, N; Bunce, C; Xing, W; Foot, B; Tuft, S

    2015-01-01

    Purpose To determine incidence and management of acute corneal hydrops in the UK. Methods We used the BOSU report card system to survey cases of acute corneal hydrops in patients with keratoconus that occurred in the UK between November 2009 and December 2010. Ophthalmologists who reported a case were sent an initial questionnaire, with a follow-up questionnaire after 6 months. We collected information on the demographics, complications, changes in visual acuity, and management. The 2011 National Census was used as a source for population and ethnicity in the UK. Results There were 73 incident cases of acute corneal hydrops, with a response to the initial questionnaire for 64 (88%) patients and follow-up data at 6 months for 57 (78%) patients. For the 64 confirmed cases the median (interquartile range) age of onset was 31.9 (23.2, 41.3) years and 48 (75%) of the cases occurred in males. A total of 42 (66%) patients were white, 14 (22%) were South Asian, and 7 (11%) were black. The proportion of South Asian and black patients with acute corneal hydrops was significantly higher than in the general population (P<0.001). The minimum estimated annual incidence of acute corneal hydrops in patients with keratoconus was estimated to be 1.43 (1.10, 1.83) per 1000. At 6 months following acute corneal hydrops a decision to proceed with keratoplasty had been made for 12 (20.3%) patients. Conclusions This is the first population-based estimate of the incidence of acute corneal hydrops in keratoconus. PMID:25592120

  4. Acute corneal hydrops in keratoconus: a national prospective study of incidence and management.

    PubMed

    Barsam, A; Petrushkin, H; Brennan, N; Bunce, C; Xing, W; Foot, B; Tuft, S

    2015-04-01

    PurposeTo determine incidence and management of acute corneal hydrops in the UK.MethodsWe used the BOSU report card system to survey cases of acute corneal hydrops in patients with keratoconus that occurred in the UK between November 2009 and December 2010. Ophthalmologists who reported a case were sent an initial questionnaire, with a follow-up questionnaire after 6 months. We collected information on the demographics, complications, changes in visual acuity, and management. The 2011 National Census was used as a source for population and ethnicity in the UK.ResultsThere were 73 incident cases of acute corneal hydrops, with a response to the initial questionnaire for 64 (88%) patients and follow-up data at 6 months for 57 (78%) patients. For the 64 confirmed cases the median (interquartile range) age of onset was 31.9 (23.2, 41.3) years and 48 (75%) of the cases occurred in males. A total of 42 (66%) patients were white, 14 (22%) were South Asian, and 7 (11%) were black. The proportion of South Asian and black patients with acute corneal hydrops was significantly higher than in the general population (P<0.001). The minimum estimated annual incidence of acute corneal hydrops in patients with keratoconus was estimated to be 1.43 (1.10, 1.83) per 1000. At 6 months following acute corneal hydrops a decision to proceed with keratoplasty had been made for 12 (20.3%) patients.ConclusionsThis is the first population-based estimate of the incidence of acute corneal hydrops in keratoconus.

  5. Acute Corneal Hydrops 3 Years after Intra-corneal Ring Segments and Corneal Collagen Cross-linking

    PubMed Central

    Antonios, Rafic; Dirani, Ali; Fadlallah, Ali; Chelala, Elias; Hamadeh, Adib; Jarade, Elias

    2016-01-01

    This case report describes a 15-year-old male with allergic conjunctivitis and keratoconus, who underwent uneventful intra-corneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in the right eye. During the follow-up periods, the patient was noted to have several episodes of allergic conjunctivitis that were treated accordingly. At the 2 years postoperatively, he presented with another episode of allergic conjunctivitis and progression of keratoconus was suspected on topography. However, the patient was lost to follow-up, until he presented with acute hydrops at 3 years postoperatively. There are no reported cases of acute corneal hydrops in cross-linked corneas. We suspect the young age, allergic conjunctivitis and eye rubbing may be a risk factors associated with possible progression of keratoconus after CXL. Prolonged follow-up and aggressive control of the allergy might be necessary in similar cases. PMID:26957859

  6. Treatment of acute corneal hydrops with intracameral C3F8 in a patient of pellucid marginal degeneration with keratoglobus.

    PubMed

    Kaushal, Sameer; Sharma, Namrata; Vajpayee, Rasik B

    2007-11-01

    We report the use of perfluoropropane (C(3)F(8)) gas for the treatment of acute hydrops with intrastromal cleft in a case of pellucid marginal degeneration with keratoglobus. Acute hydrops in a 36-year-old man with pellucid marginal degeneration with keratoglobus was treated with intracameral injection of 0.3 mL isoexpansile C(3)F(8) (14%). Reduction in corneal haze was seen beginning from the third postoperative day. Significant clearing had taken place by the end of the second week with the closure of intrastromal cleft. Best corrected visual acuity improved from finger counting at 1 foot preoperatively to 6/18 after 2 weeks. There was no postoperative rise in intraocular pressure or cataract formation. Intracameral injection of C(3)F(8) may possibly be a viable treatment option for acute hydrops in a case of corneal ectasia. Larger studies are required to clarify the role of intracameral gas injection in the treatment of acute hydrops in corneal ectasia.

  7. Infectious keratitis with corneal perforation associated with corneal hydrops and contact lens wear in keratoconus.

    PubMed Central

    Donnenfeld, E D; Schrier, A; Perry, H D; Ingraham, H J; Lasonde, R; Epstein, A; Farber, B

    1996-01-01

    BACKGROUND: Corneal perforation is an uncommon complication associated with keratoconus. The first cases of infectious keratitis and corneal perforation associated with corneal hydrops and contact lens wear are reported in two keratoconus patients. METHODS: A retrospective chart review and histopathological examination were carried out. RESULTS: Both patients progressed to corneal perforation and emergency penetrating keratoplasty. One patient cultured Fusarium and the second patient Serratia marcesens. Both patients wore contact lenses against medical advice. CONCLUSIONS: The tear in Descement's membrane, stromal oedema, and epithelial bedewing associated with corneal hydrops results in loss of the epithelial-endothelial barrier of the cornea, creating a conduit for infectious organisms through the cornea. Acute hydrops associated with epithelial keratitis, stromal swelling, and a Descement's membrane tear may be a significant risk factor for infectious keratitis and corneal perforation. Contact lenses should not be worn during an active corneal hydrops owing to the increased risk for severe infectious keratitis and corneal perforation. Images PMID:8695560

  8. Spontaneous Corneal Hydrops in a Patient with a Corneal Ulcer

    PubMed Central

    Batawi, Hatim; Kothari, Nikisha; Camp, Andrew; Bernhard, Luis; Karp, Carol L.; Galor, Anat

    2016-01-01

    Purpose We report the case of a 77-year-old man with no history of keratoconus or other ectatic disorders who presented with corneal hydrops in the setting of a corneal ulcer. The risk factors, pathogenesis and treatment options of corneal hydrops are discussed. Method This is an observational case report study. Results A 77-year-old man presented with a 1-day history of severe pain, redness, mucous discharge and photophobia in the right eye. A slit-lamp examination of the right eye showed an area of focal corneal edema and protrusion. Within the area of edema and protrusion, there was an infiltrate with an overlying epithelial defect consistent with an infectious corneal ulcer. The Seidel test showed no leakage, so a clinical diagnosis of corneal hydrops associated with nonperforated corneal ulcer was made. With appropriate antibiotic treatment, the corneal ulcer and hydrops both resolved over a 1-month period. Conclusion Corneal hydrops can occur in the setting of corneal infections. PMID:26889160

  9. Corneal Hydrops in Pellucid Marginal Degeneration: A Case Series

    PubMed Central

    Bhandari, Vipul; Ganesh, Sri

    2015-01-01

    Purpose To report an unusual presentation of pellucid marginal degeneration (PMD) and its management by using air injection and tension sutures. Case Report We report 2 cases with a history of acute pain and loss of vision. Examination revealed hydrops at the 6–9 o'clock meridian with Descemet's membrane detachment and tear at the same area and advanced PMD in the other eye. Discussion Air injection with suturing to treat the hydrops in PMD and crescentic excision with lamellar grafting instead of lamellar keratoplasty lead to better results than conservative management. Conclusion Corneal hydrops and perforation in patients with PMD is a rare presentation and can be managed by tension sutures and air injection. PMID:26265904

  10. Bilateral Keratoconus and Corneal Hydrops Associated with Eye Rubbing in a 7-year-old Girl

    PubMed Central

    Panahi-Bazaz, Mahmoud-Reza; Sharifipour, Farideh; Moghaddasi, Alireza

    2014-01-01

    Purpose To report a young child with bilateral keratoconus in the context of vernal keratoconjunctivitis (VKC) who developed bilateral corneal hydrops associated with eye rubbing, and to discuss the pathogenesis and review the pertinent literature. Case Report A seven-year-old girl with VKC and asymmetric keratoconus developed corneal hydrops due to habitual eye rubbing. Corneal edema subsided within 16 weeks in her right eye and 9 weeks in the left eye with subsequent corneal scarring. Conclusion Continuous mechanical trauma, such as eye rubbing, plays a significant role in the pathogenesis of keratoconus and subsequent hydrops even in childhood. PMID:24982739

  11. Pneumodescemetopexy with perfluoroethane (C2F6) for the treatment of acute hydrops secondary to keratoconus

    PubMed Central

    Ting, D SJ; Srinivasan, S

    2014-01-01

    Purpose To evaluate the efficacy and safety of pneumodescemetopexy with intracameral perfluoroethane (C2F6) gas for the treatment of acute hydrops secondary to keratoconus. Methods Retrospective, non-comparative, interventional case series. Eight eyes of eight patients who presented with acute hydrops secondary to keratoconus between July 2009 and September 2013 were consecutively recruited. All were treated with intracameral 14% isoexpansile concentration of C2F6. Preoperative and postoperative best-corrected visual acuities (BCVA), intraoperative and postoperative complications, and time taken for resolution of corneal oedema were assessed. Results All the patients, except for one, were followed up for 1 year. The mean age of the cohort was 29.1±13.5 years. BCVA at presentation was 6/60 or less in all patients. Improvement of BCVA was achieved postoperatively in seven (87.5%) patients, with three (37.5%) patients achieving a BCVA of 6/18. The average time between initial presentation and complete resolution of corneal oedema was 60.0±32.1 days. The C2F6 gas persisted in the anterior chamber between 6 and 8 days. All the patients required only one injection during the treatment period. There was no intraoperative or postoperative complication noted during the follow-up period. Conclusion Pneumodescemetopexy with intracameral isoexpansile concentration of C2F6 gas serves as a safe and effective treatment modality for patients with acute hydrops secondary to keratoconus. PMID:24833179

  12. Lipopolysaccharide induced acute red eye and corneal ulcers.

    PubMed

    Schultz, C L; Morck, D W; McKay, S G; Olson, M E; Buret, A

    1997-01-01

    Using a new animal model, the aims of this study were to assess the role played by purified lipopolysaccharide (LPS) and neutrophils in the pathogenesis of acute red-eye reactions (ARE) and corneal ulcers. In addition, IL-1 alpha was assessed for its implications in the formation of corneal ulcers. Following corneal abrasion, eyes of rabbits underwent single or double exposures to various doses of LPS from Pseudomonas aeruginosa or Serratia marcescens. This protocol induced ARE symptoms, and their severity depended on the dosage, number of LPS exposures, and type of LPS used (LPS from S. marcescens showing highest virulence). Corneal ulcers were induced by delivering a high dose of Serratia LPS (100 micrograms) followed by a low dose (10 micrograms). Histopathological examination revealed that both ARE and corneal ulceration were associated with prominent neutrophil infiltration. In addition, many lymphocytes and other monocytic cells infiltrated ulcerated ocular tissue. Tear fluids obtained from ulcerated eyes contained high concentrations of a protein recognized by anti-rabbit IL-1 alpha antibodies as demonstrated by immunoblotting studies. The results indicate that LPS can induce ARE and corneal ulceration in the absence of any live bacteria. Moreover, the findings implicate the accumulation of neutrophils and IL-1 alpha-related proteins in the pathogenesis of ARE and corneal ulcers.

  13. Corneal abnormalities in Ehlers-Danlos syndrome type VI.

    PubMed

    Cameron, J A

    1993-01-01

    Eleven patients with blue sclera, limbus-to-limbus corneal thinning, hypermobile joints, and consanguineous parents were examined between January 1983 and September 1991. The clinical diagnosis was consistent with the Ehlers-Danlos syndrome type VI phenotype in all patients. A "halo" sign at the limbus was present in all patients. Corneal rupture occurred in seven patients (nine eyes) either spontaneously or following minimal trauma. Acute hydrops occurred in three patients. Bilateral microcornea was present in one patient and two patients had a unilateral increased corneal diameter as a result of secondary glaucoma after trauma. Peripheral sclerocornea was present bilaterally in five patients. Curvature abnormalities included cornea plana, keratoconus, and keratoglobus.

  14. Pathogenesis of Acute and Delayed Corneal Lesions after Ocular Exposure to Sulfur Mustard Vapor

    DTIC Science & Technology

    2012-01-01

    2000) Nanoscale topography of the basement membrane underlying the corneal epithelium of the rhesus macaque. Cell Tissue Res 299: 39–46. 28. Pal-Ghosh...DATES COVERED (From - To) 4. TITLE AND SUBTITLE Pathogenesis of acute and delayed corneal lesions after ocular exposure to 5a. CONTRACT NUMBER sulfur...involves a progressive corneal degeneration resulting in chronic ocular discomfort and impaired vision for which clinical interventions have typically

  15. Hydrops foetalis in sheep.

    PubMed

    Plant, J W; Lomas, S T; Harper, P A; Duncan, D W; Carroll, S N

    1987-10-01

    Hydrops foetalis was observed in foetuses from a sheep flock in southern New South Wales over 4 years. Ewes showed marked abdominal distension and most died at parturition, being unable to deliver large affected foetuses. These had birth weights up to 18 kg and exhibited severe generalised oedema of subcutaneous tissues, fluid accumulation in the serous cavities and oedema of the placenta. Microscopically, there was a generalised extramedullary haemopoiesis and massive oedema, consistent with a chronic foetal anaemia. No infectious or environmental factors could be incriminated in the outbreak. The clinical and pathological findings resemble those of the homozygous alpha-thalassaemia in infants associated with haemoglobin Bart's.

  16. [Non-immunologic fetal hydrops].

    PubMed

    Stejskalová, S; Dolezal, Z; Nekvasil, R

    1993-07-01

    The authors demonstrate two cases of non-immunological foetal hydrops. In the first case the initial cause of foetal hydrops was hypoalbuminaemia (hypoproteinaemia), in the second case intrauterine cardiac failure resulting from supraventricular tachycardia of unknown aetiology. The authors explain the pathogenesis of the condition, its early diagnosis and therapy. They draw attention to possible intoxication of the neonate by digoxin administered to the mother during pregnancy.

  17. Feline corneal disease.

    PubMed

    Moore, Phillip Anthony

    2005-05-01

    The cornea is naturally transparent. Anything that interferes with the cornea's stromal architecture, contributes to blood vessel migration, increases corneal pigmentation, or predisposes to corneal edema, disrupts the corneas transparency and indicates corneal disease. The color, location, and shape and pattern of a corneal lesion can help in determining the underlying cause for the disease. Corneal disease is typically divided into congenital or acquired disorders. Congenital disorders, such as corneal dermoids are rare in cats, whereas acquired corneal disease associated with nonulcerative or ulcerative keratitis is common. Primary ocular disease, such as tear film instability, adenexal disease (medial canthal entropion, lagophthalmus, eyelid agenesis), and herpes keratitis are associated with the majority of acquired corneal disease in cats. Proliferative/eosinophilic keratitis, acute bullous keratopathy, and Florida keratopathy are common feline nonulcerative disorders. Nonprogressive ulcerative disease in cats, such as chronic corneal epithelial defects and corneal sequestration are more common than progressive corneal ulcerations.

  18. Topical Antinociceptive Effect of Vanillosmopsis arborea Baker on Acute Corneal Pain in Mice

    PubMed Central

    Inocêncio Leite, Laura Hévila; Leite, Gerlânia de Oliveira; Silva Coutinho, Thales; de Sousa, Severino Denício Gonçalves; Sampaio, Renata Souza; da Costa, José Galberto Martins; de Menezes, Irwin Rose Alencar; Campos, Adriana Rolim

    2014-01-01

    This study aimed to assess the possible topical antinociceptive activity of Vanillosmopsis arborea Baker essential oil (EOVA) and to clarify the underlying mechanism, using the acute model of chemical (eye wiping) nociception in mice. EOVA (25 to 200 mg/kg; p.o. and topical) evidenced significant antinociception against chemogenic pain in the test model of formalin-induced neuroinflammatory pain. Local application of 5 M NaCl solution on the corneal surface of the eye produced a significant nociceptive behavior, characterized by eye wiping. The number of eye wipes was counted during the first 30 s. EOVA (25, 50, 100, and 200 mg/kg; p.o. and topical) significantly decreased the number of eye wipes. Naloxone, yohimbine, L-NAME, theophylline, glibenclamide, and ruthenium red had no effect on the antinociceptive effect of EOVA. However, ondansetron, p-chlorophenylalanine methyl ester (PCPA), capsazepine, prazosin, and atropine prevented the antinociception induced by EOVA. These results indicate the topical antinociceptive effect of EOVA and showed that 5-HT, α1, TRPV1, and central muscarinic receptors might be involved in the antinociceptive effect of EOVA in the acute corneal model of pain in mice. PMID:24660017

  19. Descemet stripping endothelial keratoplasty in a patient with keratoglobus and chronic hydrops secondary to a spontaneous descemet membrane tear.

    PubMed

    Kolomeyer, Anton M; Chu, David S

    2013-01-01

    Purpose. To report the use of Descemet stripping endothelial keratoplasty (DSEK) in a patient with keratoglobus and chronic hydrops. Case Report. We describe a case of a 28-year-old man with bilateral keratoglobus and chronic hydrops in the right eye secondary to spontaneous Descemet membrane tear. The patient presented with finger counting (CF) vision, itching, foreign body sensation, and severe photophobia in the right eye. Peripheral corneal thinning with central corneal protrusion and Descemet membrane tear spanning from 4 to 7 o'clock was noted on slit lamp examination. The right eye cornea was 15 mm in the horizontal diameter. After a 5.5-month loss to follow-up, the patient presented with discomfort, photophobia, decreasing vision, and tearing in the right eye. Vision was 20/60 with pinhole. 360-degree peripheral corneal ectasia with mild neovascularization and hydrops was present. Over the next few months, the patient complained of photophobia and intermittent eye pain. His vision deteriorated to CF, he developed corneal scarring with bullae, and a DSEK was performed. Eight months postoperatively, best-corrected vision improved to 20/30, cornea was clear, and the DSEK graft was stable. Conclusions. Nonresolving hydrops secondary to Descemet membrane tear in a patient with keratoglobus may result in permanent endothelial cell damage and scar formation. This may be successfully treated with DSEK.

  20. Descemet Stripping Endothelial Keratoplasty in a Patient with Keratoglobus and Chronic Hydrops Secondary to a Spontaneous Descemet Membrane Tear

    PubMed Central

    Kolomeyer, Anton M.; Chu, David S.

    2013-01-01

    Purpose. To report the use of Descemet stripping endothelial keratoplasty (DSEK) in a patient with keratoglobus and chronic hydrops. Case Report. We describe a case of a 28-year-old man with bilateral keratoglobus and chronic hydrops in the right eye secondary to spontaneous Descemet membrane tear. The patient presented with finger counting (CF) vision, itching, foreign body sensation, and severe photophobia in the right eye. Peripheral corneal thinning with central corneal protrusion and Descemet membrane tear spanning from 4 to 7 o'clock was noted on slit lamp examination. The right eye cornea was 15 mm in the horizontal diameter. After a 5.5-month loss to follow-up, the patient presented with discomfort, photophobia, decreasing vision, and tearing in the right eye. Vision was 20/60 with pinhole. 360-degree peripheral corneal ectasia with mild neovascularization and hydrops was present. Over the next few months, the patient complained of photophobia and intermittent eye pain. His vision deteriorated to CF, he developed corneal scarring with bullae, and a DSEK was performed. Eight months postoperatively, best-corrected vision improved to 20/30, cornea was clear, and the DSEK graft was stable. Conclusions. Nonresolving hydrops secondary to Descemet membrane tear in a patient with keratoglobus may result in permanent endothelial cell damage and scar formation. This may be successfully treated with DSEK. PMID:23710398

  1. [Hydrops fetalis associated with Noonan syndrome].

    PubMed

    Paupe, A; Chassevent, J; Lenclen, R; Blanc, P; Carbajal, R; Hoenn, E; Olivier-Martin, M

    1991-01-01

    A case of Noonan syndrome associated with hydrops fetalis has been reported; it is recalled that morphological anomalies common to both Turner and Noonan syndromes depend on similar lymphatic anomalies. In the present case it is therefore proposed that the malformations of Noonan syndrome and hydrops fetalis proceed from the same lymphatic anomalies.

  2. Establishment and Characterization of an Air-Liquid Canine Corneal Organ Culture Model To Study Acute Herpes Keratitis

    PubMed Central

    Harman, Rebecca M.; Bussche, Leen; Ledbetter, Eric C.

    2014-01-01

    ABSTRACT Despite the clinical importance of herpes simplex virus (HSV)-induced ocular disease, the underlying pathophysiology of the disease remains poorly understood, in part due to the lack of adequate virus–natural-host models in which to study the cellular and viral factors involved in acute corneal infection. We developed an air-liquid canine corneal organ culture model and evaluated its susceptibility to canine herpesvirus type 1 (CHV-1) in order to study ocular herpes in a physiologically relevant natural host model. Canine corneas were maintained in culture at an air-liquid interface for up to 25 days, and no degenerative changes were observed in the corneal epithelium during cultivation using histology for morphometric analyses, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays, and transmission electron microscopy (TEM). Next, canine corneas were inoculated with CHV-1 for 48 h, and at that time point postinfection, viral plaques could be visualized in the corneal epithelium and viral DNA copies were detected in both the infected corneas and culture supernatants. In addition, we found that canine corneas produced proinflammatory cytokines in response to CHV-1 infection similarly to what has been described for HSV-1. This emphasizes the value of our model as a virus–natural-host model to study ocular herpesvirus infections. IMPORTANCE This study is the first to describe the establishment of an air-liquid canine corneal organ culture model as a useful model to study ocular herpesvirus infections. The advantages of this physiologically relevant model include the fact that (i) it provides a system in which ocular herpes can be studied in a virus–natural-host setting and (ii) it reduces the number of experimental animals needed. In addition, this long-term explant culture model may also facilitate research in other fields where noninfectious and infectious ocular diseases of dogs and humans are being studied. PMID

  3. Corneal Disorders

    MedlinePlus

    ... Injuries Dystrophies - conditions in which parts of the cornea lose clarity due to a buildup of cloudy material Treatments of corneal disorders include medicines, corneal transplantation, and corneal laser surgery. NIH: National Eye Institute

  4. DNA flow cytometric analysis in variable types of hydropic placentas

    PubMed Central

    Atabaki pasdar, Fatemeh; Khooei, Alireza; Fazel, Alireza; Rastin, Maryam; Tabasi, Nafise; Peirouvi, Tahmineh; Mahmoudi, Mahmoud

    2015-01-01

    Background: Differential diagnosis between complete hydatidiform mole, partial hydatidiform mole and hydropic abortion, known as hydropic placentas is still a challenge for pathologists but it is very important for patient management. Objective: We analyzed the nuclear DNA content of various types of hydropic placentas by flowcytometry. Materials and Methods: DNA ploidy analysis was performed in 20 non-molar (hydropic and non-hydropic spontaneous abortions) and 20 molar (complete and partial moles), formalin-fixed, paraffin-embedded tissue samples by flow cytometry. The criteria for selection were based on the histopathologic diagnosis. Results: Of 10 cases histologically diagnosed as complete hydatiform mole, 9 cases yielded diploid histograms, and 1 case was tetraploid. Of 10 partial hydatidiform moles, 8 were triploid and 2 were diploid. All of 20 cases diagnosed as spontaneous abortions (hydropic and non-hydropic) yielded diploid histograms. Conclusion: These findings signify the importance of the combined use of conventional histology and ploidy analysis in the differential diagnosis of complete hydatidiform mole, partial hydatidiform mole and hydropic abortion. PMID:26221125

  5. Corneal Emergencies.

    PubMed

    Belknap, Ellen B

    2015-09-01

    Corneal emergencies can be due to a number of different causes and may be vision threatening if left untreated. In an attempt to stabilize the cornea, it is of benefit to place an Elizabethan collar on the patient to prevent further corneal damage. This article discusses the diagnosis, prognosis, and management of corneal emergencies in dogs and cats.

  6. Corneal dystrophies

    PubMed Central

    Klintworth, Gordon K

    2009-01-01

    The term corneal dystrophy embraces a heterogenous group of bilateral genetically determined non-inflammatory corneal diseases that are restricted to the cornea. The designation is imprecise but remains in vogue because of its clinical value. Clinically, the corneal dystrophies can be divided into three groups based on the sole or predominant anatomical location of the abnormalities. Some affect primarily the corneal epithelium and its basement membrane or Bowman layer and the superficial corneal stroma (anterior corneal dystrophies), the corneal stroma (stromal corneal dystrophies), or Descemet membrane and the corneal endothelium (posterior corneal dystrophies). Most corneal dystrophies have no systemic manifestations and present with variable shaped corneal opacities in a clear or cloudy cornea and they affect visual acuity to different degrees. Corneal dystrophies may have a simple autosomal dominant, autosomal recessive or X-linked recessive Mendelian mode of inheritance. Different corneal dystrophies are caused by mutations in the CHST6, KRT3, KRT12, PIP5K3, SLC4A11, TACSTD2, TGFBI, and UBIAD1 genes. Knowledge about the responsible genetic mutations responsible for these disorders has led to a better understanding of their basic defect and to molecular tests for their precise diagnosis. Genes for other corneal dystrophies have been mapped to specific chromosomal loci, but have not yet been identified. As clinical manifestations widely vary with the different entities, corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. Main differential diagnoses include various causes of monoclonal gammopathy, lecithin-cholesterol-acyltransferase deficiency, Fabry disease, cystinosis, tyrosine transaminase deficiency, systemic lysosomal storage diseases (mucopolysaccharidoses

  7. Histomorphometric and proteomic analysis of the acute rabbit corneal tissue response following in vitro exposure to 1540-nm laser light

    NASA Astrophysics Data System (ADS)

    Eurell, Thomas E.; Johnson, Thomas E.; Roach, William P.

    2003-06-01

    In vitro exposures of explant rabbit corneas to single pulse 1540 nm infrared laser light operating at a pulse width of 0.8 milliseconds resulted in coagulative necrosis of both the corneal epithelium and stroma. Histomorphometric data correlated with increasing tissue radiant exposures. Histologic alterations in the corneal stroma were typical of matrix remodeling within the beam path and reactive to antibodies against matrix metalloproteinase-2. A two-dimensional electrophoretic analysis, using a mini-gel format, was developed to determine if specific corneal protein changes within tissue sections could be detected. Frozen sections taken through the center of the laser lesion were evaluated for proteomic data using tissue isoelectric focusing in the first dimension and polyacrylamide gel electrophoresis in the second dimension. Histomorphometric data describing the extent of the laser lesions were compared to the isoelectric points, molecular weights and relative densities of individual corneal proteins. Increasing radiant exposures of corneal tissues were associated with characteristic histomorphometric and proteomic changes.

  8. Topographic analysis in pellucid marginal corneal degeneration and keratoglobus.

    PubMed

    Karabatsas, C H; Cook, S D

    1996-01-01

    Pellucid marginal corneal degeneration (PMCD) is an uncommon cause of inferior peripheral corneal ectasia, affecting patients between the ages of 20 and 40 years. Although histopathologically it is considered a variant of keratoconus, it differs in that the marked corneal steepening occurs more inferiorly, above a narrow band of corneal stromal thinning concentric to the inferior limbus. Here we present two cases. The first case is a clinically typical bilateral PMCD with a characteristic pattern of irregular against-the-rule astigmatism on corneal topography. The second case had an uncommon presentation of hydrops in a clinically keratoglobic eye which showed a marked steepening of the inferior corneal periphery on corneal topography. The other eye showed both clinically and topographically the features of PMCD. Corneal topography suggested that in the second patient, PMCD may have preceded the development of keratoglobus. Keratoconus, PMCD and keratoglobus are considered to be associated as part of the spectrum of non-inflammatory corneal thinning disorders. However, although the finding of PMCD and keratoconus in fellow eyes has been reported, to the best of our knowledge progression from PMCD to keratoglobus has not previously been shown.

  9. Perinatal-lethal Gaucher disease presenting as hydrops fetalis

    PubMed Central

    BenHamida, Emira; Ayadi, Imene; Ouertani, Ines; Chammem, Maroua; Bezzine, Ahlem; BenTmime, Riadh; Attia, Leila; Mrad, Ridha; Marrakchi, Zahra

    2015-01-01

    Perinatal-lethal Gaucher disease is very rare and is considered a variant of type 2 Gaucher disease that occurs in the neonatal period. The most distinct features of perinatal-lethal Gaucher disease are non-immune hydrops fetalis. Less common signs of the disease are hepatosplenomegaly, ichthyosis and arthrogryposis. We report a case of Gaucher's disease (type 2) diagnosed in a newborn who presented with Hydrops Fetalis. PMID:26327947

  10. Assessment of corneal epithelial integrity after acute exposure to ocular hypotensive agents preserved with and without benzalkonium chloride.

    PubMed

    Whitson, Jess T; Cavanagh, H Dwight; Lakshman, Neema; Petroll, W Matthew

    2006-01-01

    The corneal toxicity of 2 intraocular pressure-lowering agents was compared in a rabbit cornea model with New Zealand White rabbits. Corneal epithelial morphology and cell size were assessed by in vivo confocal microscopy. Baseline microscopic examinations were performed on 1 eye of each animal. Two weeks later, the eyes were bathed for 3 min in travoprost 0.004% preserved without benzalkonium chloride (BAK( or latanoprost 0.005% preserved with 0.02% BAK; the eyes were then rinsed with balanced salt solution, and the corneas were again examined by confocal microscopy (n=4/group). A second group of animals was exposed to the medications through a dosing regimen of 1 drop/min (lpar3 drops total) (n=4/group). In eyes treated with travoprost without BAK (3-min bath), superficial epithelial cells were similar to baseline, as indicated by their visible cell borders and bright nuclei. In contrast, the surface cells in eyes treated with latanoprost were significantly smaller and brighter and had less distinct borders. Surface cell size was significantly smaller as compared with baseline size and as compared with rabbits treated with travoprost without BAK for 3 min. Similar effects on corneal epithelial cell morphology were observed with the 1-drop/min dosing regimen. In this rabbit model, travoprost 0.004% preserved without BAK did not cause corneal epithelial toxicity; latanoprost 0.005% induced superficial cell loss, most likely caused by the presence of a relatively high concentration of BAK (0.02%).

  11. Corneal injury

    MedlinePlus

    ... as sand or dust Ultraviolet injuries: Caused by sunlight, sun lamps, snow or water reflections, or arc- ... a corneal injury if you: Are exposed to sunlight or artificial ultraviolet light for long periods of ...

  12. Corneal Abrasions

    MedlinePlus

    ... Causes a Corneal Abrasion? Your eye has other defenses besides the orbital bone: The eyelids and eyelashes ... The Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart. ...

  13. Corneal Abrasions

    MedlinePlus

    ... fingernails short, too.Use care when putting in contact lenses. Make sure you clean them properly each day.Don’t sleep in your contact lenses.Trim low-hanging tree branches. Corneal abrasion treatment ...

  14. Corneal Abrasions

    MedlinePlus

    ... can damage the cornea. This includes dust, sand, wood shavings, hay, sparks, bugs, pieces of paper, and ... prevent a corneal abrasion, make sure to wear protection for your eyes, such as safety goggles or ...

  15. Corneal transplant

    MedlinePlus

    ... lenses to achieve the best vision. Laser vision correction may be an option if you have nearsightedness, ... Editorial team. Related MedlinePlus Health Topics Corneal Disorders Refractive Errors Browse the Encyclopedia A.D.A.M., Inc. ...

  16. Corneal Toxicity Following Exposure to Asclepias Tuberosa

    PubMed Central

    Mikkelsen, Lauge Hjorth; Hamoudi, Hassan; Gül, Cigdem Altuntas; Heegaard, Steffen

    2017-01-01

    Purpose: To present a case of corneal toxicity following exposure to milky plant latex from Asclepias tuberosa. Methods: A 70-year-old female presented with blurred vision and pain in her left eye after handling an Ascepias tuberosa. Clinical examination revealed a corneal stromal oedema with small epithelial defects. The corneal endothelium was intact and folds in Descemets membrane were observed. The oedema was treated with chloramphenicol, dexamethasone and scopolamine. Results: The corneal oedema had appeared after corneal exposure to the plant, Asclepias tuberosa, whose latex contains cardenolides that inhibit the Na+/ K+-ATPase in the corneal endothelium. The oedema resolved after 96 hours. After nine months the best corrected visual acuity was 20/20. Conclusion: Corneal toxicity has previously been reported for plants of the Asclepias family. This is a rare case describing severe corneal toxicity caused by exposure to latex from Asclepias tuberosa. Handling of plants of the Asclepias family should be kept as a differential diagnosis in cases of acute corneal toxicity.

  17. [Transplantation of corneal endothelial cells].

    PubMed

    Amano, Shiro

    2002-12-01

    culture of HCECs was possible using adult human serum. We reconstructed the cornea using cultured HCECs and human corneal stroma. The corneal stroma, on which the cell suspension of HCECs was poured, was mildly centrifuged to enhance the HCECs attachment to the stroma. The cell density of HCECs on the reconstructed cornea reached 2,500 cells/mm2. The pump function of the reconstructed cornea was measured with an Ussing chamber. The potential difference in the reconstructed cornea and normal cornea was 0.30 mV and 0.40 mV, respectively; indicating that the pump function of the reconstructed cornea is 75% of that of the normal cornea. The reconstructed cornea was transplanted to a rabbit eye and stayed transparent for 6 months after the operation. Fluorescein labeled cultured HCECs remained on the graft 1 month after the transplantation, indicating that transplanted HCECs contributed to the transparency of the graft. The possibility of using artificial stroma or porcine corneal stroma as a carrier of cultured HCECs was investigated. The artificial stroma made of alkaline-treated collagen could not be sutured but showed good transparency, biocompatibility, and cell-attachability. Porcine corneal stroma, expressing little xeno-sugar antigen alpha-gal epitope, induced no super acute rejection but mild cellular rejection when transplanted in the cornea of animals possessing natural antibody to alpha-gal epitope. The cornea reconstructed with porcine corneal stroma and HCECs had an average cell density of 1721/mm2 and had approximately 60% of the pump function of a normal cornea. As new technologies in corneal transplantation, the application of self immature cells and the direct delivery of cultured HCECs into the anterior chamber were investigated. Part of rat mononuclear cells that were obtained from the bone marrow and injected into the rat anterior chamber transformed into corneal endothelium-like cells, suggesting that self immature cells can transform into corneal

  18. Digitalization of the mother in treating hydrops fetalis in monochorionic twin with Ebstein's anomaly. Case report.

    PubMed

    Koike, T; Minakami, H; Shiraishi, H; Ogawa, S; Matsubara, S; Honma, Y; Sato, I

    1997-01-01

    Hydrops fetalis thought to be due to Ebstein's anomaly was seen at 22 weeks' gestation in one of two fetuses with a monochorionic placenta. Hydrops was treated with maternal digitalization and resolved by the 28th week of gestation. Hydrops did not recur while maternal digitalization continued. A clinical diagnosis of twin-to-twin transfusion syndrome required termination of the pregnancy at 33 weeks of gestation. The twin with Ebstein's anomaly died 22 hours after birth. The other twin survived and was normal at 19 months of age. Thus, administration of digitalis to the mother controlled hydrops fetalis in one fetus, and ultimately led to the survival of the healthy infant.

  19. [Severe hydrops fetalis in a first trimester pregnancy with Ulrich-Turner syndrome].

    PubMed

    Klare, P; Sydow, P; Körner, H

    1992-01-01

    We report about a case of abundant hydropic evolution of a fetus in the first trimester of gestation. Already in the 8th week of gestation we diagnosed the first references of failure with transvaginal ultrasound. In the following three weeks we observed the progression of the hydrops. The genetic research of fetal tissue after induced abortion show the karyotype 45 X0.

  20. Corneal ulcers in horses.

    PubMed

    Williams, Lynn B; Pinard, Chantale L

    2013-01-01

    Corneal ulceration is commonly diagnosed by equine veterinarians. A complete ophthalmic examination as well as fluorescein staining, corneal cytology, and corneal bacterial (aerobic) and fungal culture and sensitivity testing are necessary for all infected corneal ulcers. Appropriate topical antibiotics, topical atropine, and systemic NSAIDs are indicated for all corneal ulcers. If keratomalacia (melting) is observed, anticollagenase/antiprotease therapy, such as autologous serum, is indicated. If fungal infection is suspected, antifungal therapy is a necessity. Subpalpebral lavage systems allow convenient, frequent, and potentially long-term therapy. Referral corneal surgeries provide additional therapeutic options when the globe's integrity is threatened or when improvement has not been detected after appropriate therapy.

  1. Survival and integration of tissue-engineered corneal stroma in a model of corneal ulcer.

    PubMed

    Zhang, Chao; Nie, Xin; Hu, Dan; Liu, Yuan; Deng, Zhihong; Dong, Rui; Zhang, Yongjie; Jin, Yan

    2007-08-01

    Tissue-engineered replacement of diseased or damaged tissue has become a reality for some types of tissue, such as skin and cartilage. Tissue-engineered corneal stroma represents a promising concept to overcome the limitations of cornea replacement with allograft. In this study, porcine cornea was decellularized by a series of extraction methods, and the in vivo biocompatibility of the scaffold was measured subcutaneously in rabbits (n = 8). These were not acutely rejected and no abscesses were observed by hematoxylin and eosin staining at the 8th week, indicating that the scaffolds had good biocompatibility. To investigate the potential value of clinical applications, rabbit stromal keratocytes were implanted onto decellularized scaffolds to fabricate tissue-engineered corneal stroma. Allograft, tissue-engineered corneal stroma, or scaffolds were implanted into a model of corneal ulcer. The survival and reconstruction of corneal transplantation were morphologically evaluated by light and electron microscopy until the 32nd week after implantation. Experiments involving transplantation indicated that the epithelial and stromal defect healed quickly, with improvement in corneal clarity. The integration of the graft was accompanied by neurite ingrowth from the host tissue. By 16 weeks after transplantation, the cornea had gradually regained an intact state similar to that of normal cornea. Our results demonstrate that the tissue-engineered corneal stroma with allogenetic cells is a promising therapeutic method for corneal injury.

  2. Corneal transplant - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000243.htm Corneal transplant - discharge To use the sharing features on this page, please enable JavaScript. You had a corneal transplant. Most of the tissue of your cornea (the ...

  3. Partial-thickness corneal tissue restoration after a chemical burn

    PubMed Central

    Galan, Alessandro; Catania, Anton Giulio; Giudice, Giuseppe Lo

    2016-01-01

    Purpose We describe a case of full-thickness corneal restoration after an acute corneal burn with an acid agent. Methods A 32-year-old male reported painful discomfort, redness, photophobia, and a decrease in visual acuity in the left eye after a unilateral burn with an acid agent. Slit-lamp examination revealed massive corneal melting involving necrotic sequestrum of the entire corneal surface. Surgical approach was carried out in order to preserve residual ocular tissues. Results Extensive corneal–conjunctival layer curettage of the necrotic tissue was performed showing perfectly clear undamaged deep lamellar corneal layers. The patient underwent multilayered amniotic membrane transplantation and total capsular–conjunctival flap in order to preserve ocular tissue from further melting or corneal perforation. A complete and spontaneous “restitutio ad integrum” of the corneal layers was shown during the follow-up. The cornea was perfectly clear with restored normal anatomical architecture. Conclusion In this case, a spontaneous full-thickness corneal tissue restoration occurred after an acute chemical burn. Studies about the mechanisms whereby different cells interact and replicate within the stroma may unveil the biology behind corneal regeneration and transparency. PMID:27194918

  4. Reversal of foetal hydrops and foetal tachyarrhythmia associated with maternal diabetic coma.

    PubMed

    Greco, P; Vimercati, A; Giorgino, F; Loverro, G; Selvaggi, L

    2000-11-01

    Foetal hydrops is always a challenge for the clinician. We report a case of tachycardia associated with hydrops and hydramnios in a pregnancy complicated with diabetic coma at 28 weeks gestation. Normal foetal heart rate was recorded immediately after correction of maternal acidotic status and hydrops eventually disappeared. The woman was delivered at 32 weeks and the baby had an uncomplicated postnatal course. We hypothesise that maternal ketoacidosis has been the precipitating factor of tachycardia and congestive heart failure and that this case is conceptually similar to the "late death" phenomenon, reported in cases of poorly controlled maternal diabetes.

  5. Hydropic degeneration of the anterior pituitary gland (adenohypophysis) in uremic rats.

    PubMed

    Levine, Seymour; Saltzman, Arthur

    2004-03-01

    We observed hydropic degeneration of the anterior pituitary in rats made uremic by nephrotoxic chemicals, especially when the uremic rats were given a pure carbohydrate diet beforehand. The hydropic degeneration caused loss of nuclear and cytoplasmic content of many or most anterior pituitary cells. It was readily visible in paraffin sections by light microscopy. It was exaggerated when water was injected after the nephrotoxin and it was greatly reduced if saline was injected after the nephrotoxin. Low serum sodium levels in affected rats and the response to saline injection suggested that the mechanism for development of hydropic degeneration of the anterior pituitary gland involved hyponatremia. Depletion of total body sodium probably accounts for the enhancement of hydropic degeneration by the pure carbohydrate diet. Morphologic lesions of the anterior pituitary related to hyponatremia and uremia have not been described previously.

  6. Keratoglobus in the Rubinstein-Taybi syndrome.

    PubMed Central

    Nelson, M E; Talbot, J F

    1989-01-01

    The case of a 20-year-old male with the Rubinstein-Taybi syndrome associated with unilateral acute corneal hydrops is presented. The initial findings were of keratoglobus, but after the corneal oedema had settled the cornea assumed a more conical contour. The relationship between keratoglobus, keratoconus, and acute hydrops is discussed. Images PMID:2730863

  7. Keratoglobus in the Rubinstein-Taybi syndrome.

    PubMed

    Nelson, M E; Talbot, J F

    1989-05-01

    The case of a 20-year-old male with the Rubinstein-Taybi syndrome associated with unilateral acute corneal hydrops is presented. The initial findings were of keratoglobus, but after the corneal oedema had settled the cornea assumed a more conical contour. The relationship between keratoglobus, keratoconus, and acute hydrops is discussed.

  8. The Prevalence of High-Riding Jugular Bulb in Patients with Suspected Endolymphatic Hydrops

    PubMed Central

    Brook, Christopher D.; Buch, Karen; Kaufmann, Matthew; Sakai, Osamu; Devaiah, Anand K.

    2015-01-01

    Background To determine the prevalence of a high-riding jugular bulb (HRJB) in the endolymphatic hydrops population. Methods This was a retrospective chart and radiology review of patients seen at a tertiary care medical center. Patients were identified using the International Classification of Diseases, 9th edition, code 386.xx (Meniere disease–unspecified), and were required to have undergone an imaging study that included views of the jugular bulb that were available for review. A radiologist then evaluated all of the imaging studies for evidence of HRJB or inner ear dehiscence with a jugular bulb abnormality. Results The prevalence of a HRJB in all endolymphatic hydrops patients was 9.0% (7 of 78), and it was 4.5% (7 of 156) in all ears. The prevalence of HRJB ipsilateral to an ear with endolymphatic hydrops was 4.6% (4 of 88 ears); it was 4.4% (3 of 68 ears) in ears without endolymphatic hydrops. The incidence of inner ear dehiscence with a HRJB was 1.3% (1 of 78). Electrocochleography results were not correlated with jugular bulb volume. Discussion The results of this study indicate that a small subset of patients treated for endolymphatic hydrops patients have a HRJB. Overall, these results suggest that HRJB does not play a major role in endolymphatic hydrops, although it may play a role in a few isolated patients. PMID:26682126

  9. The Prevalence of High-Riding Jugular Bulb in Patients with Suspected Endolymphatic Hydrops.

    PubMed

    Brook, Christopher D; Buch, Karen; Kaufmann, Matthew; Sakai, Osamu; Devaiah, Anand K

    2015-12-01

    Background To determine the prevalence of a high-riding jugular bulb (HRJB) in the endolymphatic hydrops population. Methods This was a retrospective chart and radiology review of patients seen at a tertiary care medical center. Patients were identified using the International Classification of Diseases, 9th edition, code 386.xx (Meniere disease-unspecified), and were required to have undergone an imaging study that included views of the jugular bulb that were available for review. A radiologist then evaluated all of the imaging studies for evidence of HRJB or inner ear dehiscence with a jugular bulb abnormality. Results The prevalence of a HRJB in all endolymphatic hydrops patients was 9.0% (7 of 78), and it was 4.5% (7 of 156) in all ears. The prevalence of HRJB ipsilateral to an ear with endolymphatic hydrops was 4.6% (4 of 88 ears); it was 4.4% (3 of 68 ears) in ears without endolymphatic hydrops. The incidence of inner ear dehiscence with a HRJB was 1.3% (1 of 78). Electrocochleography results were not correlated with jugular bulb volume. Discussion The results of this study indicate that a small subset of patients treated for endolymphatic hydrops patients have a HRJB. Overall, these results suggest that HRJB does not play a major role in endolymphatic hydrops, although it may play a role in a few isolated patients.

  10. Select noxious stimuli induce changes on corneal nerve morphology.

    PubMed

    Hegarty, Deborah M; Hermes, Sam M; Yang, Katherine; Aicher, Sue A

    2017-06-01

    The surface of the cornea contains the highest density of nociceptive nerves of any tissue in the body. These nerves are responsive to a variety of modalities of noxious stimuli and can signal pain even when activated by low threshold stimulation. Injury of corneal nerves can lead to altered nerve morphology, including neuropathic changes which can be associated with chronic pain. Emerging technologies that allow imaging of corneal nerves in vivo are spawning questions regarding the relationship between corneal nerve density, morphology, and function. We tested whether noxious stimulation of the corneal surface can alter nerve morphology and neurochemistry. We used concentrations of menthol, capsaicin, and hypertonic saline that evoked comparable levels of nocifensive eye wipe behaviors when applied to the ocular surface of an awake rat. Animals were sacrificed and corneal nerves were examined using immunocytochemistry and three-dimensional volumetric analyses. We found that menthol and capsaicin both caused a significant reduction in corneal nerve density as detected with β-tubulin immunoreactivity 2 hr after stimulation. Hypertonic saline did not reduce nerve density, but did cause qualitative changes in nerves including enlarged varicosities that were also seen following capsaicin and menthol stimulation. All three types of noxious stimuli caused a depletion of CGRP from corneal nerves, indicating that all modalities of noxious stimuli evoked peptide release. Our findings suggest that studies aimed at understanding the relationship between corneal nerve morphology and chronic disease may also need to consider the effects of acute stimulation on corneal nerve morphology.

  11. Hereditary deafness with hydrops and anomalous calcium phosphate deposits

    SciTech Connect

    Johnsson, L.G.; Rouse, R.C.; Hawkins, J.E. Jr.; Kingsley, T.C.; Wright, C.G.

    1981-11-01

    The temporal bones from a 58-year-old white woman who had had hereditary congenital deafness were examined with the techniques of microdissection and surface preparations followed by sectioning of the modiolus. There was bilateral, almost total sensorineural degeneration, which also involved the saccule. The degeneration of the distal processes of the cochlear neurons in the osseous spiral lamina was almost complete, whereas numerous ganglion cells and proximal processes remained in the modiolus and the internal auditory canal. Severe cochleo-saccular hydrops was present in the left ear with Reissner's membrane bulging into the horizontal canal. X-ray diffraction and electron probe analysis were used to study the abnormal crystalline deposits in both ears. On the left side the saccular otoconia were composed of calcite, but the utricular macula was covered by a crust of apatite spherulites. More apatite occurred around the maculae and in the scala media. The cupulae were composed of apatite and octacalcium phosphate. On the right side the utricular otoconia were of normal calcite, but there was a deposit of apatite on the macula sacculi. The upper part of the scala media was completely filled by a deposit of apatite and octacalcium phosphate.

  12. Characterization of Corneal Indentation Hysteresis.

    PubMed

    Ko, Match W L; Dongming Wei; Leung, Christopher K S

    2015-01-01

    Corneal indentation is adapted for the design and development of a characterization method for corneal hysteresis behavior - Corneal Indentation Hysteresis (CIH). Fourteen porcine eyes were tested using the corneal indentation method. The CIH measured in enucleated porcine eyes showed indentation rate and intraocular pressure (IOP) dependences. The CIH increased with indentation rate at lower IOP (<; 25 mmHg) and decreased with indentation rate at higher IOP (> 25 mmHg). The CIH was linear proportional to the IOP within an individual eye. The CIH was positively correlated with the IOP, corneal in-plane tensile stress and corneal tangent modulus (E). A new method based on corneal indentation for the measurement of Corneal Indentation Hysteresis in vivo is developed. To our knowledge, this is the first study to introduce the corneal indentation hysteresis and correlate the corneal indentation hysteresis and corneal tangent modulus.

  13. Endolymphatic Hydrops Reversal following Acetazolamide Therapy: Demonstration with Delayed Intravenous Contrast-Enhanced 3D-FLAIR MRI.

    PubMed

    Sepahdari, A R; Vorasubin, N; Ishiyama, G; Ishiyama, A

    2016-01-01

    Endolymphatic hydrops, the primary pathologic alteration in Menière disease, can be visualized by using delayed intravenous contrast-enhanced 3D-FLAIR MR imaging. It is not known whether MR imaging-demonstrable changes of hydrops fluctuate with disease activity or are fixed. We describe the results of baseline and posttreatment MR imaging studies in a group of subjects with Menière disease with hydrops who were treated with acetazolamide. Seven subjects with untreated Menière disease with MR imaging evidence of hydrops had repeat MR imaging during acetazolamide treatment. Symptoms and imaging findings were assessed at each time point. Five subjects showed symptom improvement, of whom 3 had improvement or resolution of hydrops. One subject had recurrent symptoms with recurrent hydrops after discontinuing therapy. Two had unchanged hydrops despite symptom improvement. Subjects with unchanged symptoms had unchanged hydrops. Hydrops reversal may be seen with acetazolamide treatment in Menière disease. MR imaging may provide an additional biomarker of disease.

  14. Significance of corneal arcus.

    PubMed

    Raj, K Mohan; Reddy, P Arun Subhash; Kumar, Vikram Chella

    2015-04-01

    The corneal arcus consists of cholesterol, phospholipids and triglycerides. As serum triglyceride is one of the accurate of lipid metabolic state, greater importance was given, and it was found to be elevated in 72% of patients and a positive correlation with increasing age. This suggests a strong correlation between impairment of lipid metabolism and incidence of corneal arcus.

  15. Significance of corneal arcus

    PubMed Central

    Raj, K. Mohan; Reddy, P. Arun Subhash; Kumar, Vikram Chella

    2015-01-01

    The corneal arcus consists of cholesterol, phospholipids and triglycerides. As serum triglyceride is one of the accurate of lipid metabolic state, greater importance was given, and it was found to be elevated in 72% of patients and a positive correlation with increasing age. This suggests a strong correlation between impairment of lipid metabolism and incidence of corneal arcus. PMID:26015693

  16. Corneal-shaping electrode

    DOEpatents

    Doss, James D.; Hutson, Richard L.

    1982-01-01

    The disclosure relates to a circulating saline electrode for changing corneal shape in eyes. The electrode comprises a tubular nonconductive electrode housing having an annular expanded base which has a surface substantially matched to a subject corneal surface. A tubular conductive electrode connected to a radiofrequency generating source is disposed within the electrode housing and longitudinally aligned therewith. The electrode has a generally hemispherical head having at least one orifice. Saline solution is circulated through the apparatus and over the cornea to cool the corneal surface while radiofrequency electric current emitted from the electrode flows therefrom through the cornea to a second electrode, on the rear of the head. This current heats the deep corneal stroma and thereby effects corneal reshaping as a biological response to the heat.

  17. Current status of corneal xenotransplantation.

    PubMed

    Kim, Mee Kum; Hara, Hidetaka

    2015-11-01

    Corneal allo-transplantation is a well-established technique to treat corneal blindness. However, the limited availability of human donors demands the exploration of alternative treatments such as corneal xenotransplantation (e.g., pigs as donors) and bioengineered corneas. Since the first attempt of corneal xenotransplantation using a donor pig cornea in 1844, great advances have been made in the development of genetically-engineered pigs, effective immunosuppressive protocols and the establishment of guidelines for the conduction of clinical trials. We highlight immunological and physio-anatomical barriers of corneal xenotransplantation, recent progress of corneal xenotransplantation in non-human-primates studies, and regulatory guidelines to conduct clinical trials for corneal xenotransplantation.

  18. Hypertonic saline in the treatment of corneal jellyfish stings.

    PubMed

    Yu Yao, Hsin; Cho, Ta Hsiung; Lu, Ching Hsiang; Lin, Feng Chi; Horng, Chi Ting

    2016-02-01

    A 20-year-old male soldier was hit by the jellyfish. The ophthalmic examination revealed that epithelial keratitis and corneal oedema in the right eye. We prescribed 3% NaCl eyedrops and 0.3% Norfloxacin eyedrops in the treatment of the corneal jellyfish stings. Two weeks later, the cornea in the right eye healed. In this case report, 3% NaCl eyedrops was effective in the treatment of acute phase of jellyfish stings of the cornea.

  19. Corneal blindness and xenotransplantation.

    PubMed

    Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K C

    2014-01-01

    Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

  20. Primary Congenital Lymphedema Complicated by Hydrops Fetalis: A Case Report and Review of the Literature

    PubMed Central

    Connell, Matthew

    2013-01-01

    Introduction. Primary congenital lymphedema is a rare disorder associated with insufficient development of lymphatic vessels. Usually most patients present with lower extremity edema seen sonographically. Rarely primary congenital lymphedema may be associated with severe lymphatic dysfunction resulting in hydrops fetalis. Case. A 27-year-old primigravida with a family history of leg swelling throughout multiple generations was diagnosed early in the third trimester with hydrops fetalis. Delivery was undertaken at 32 weeks for nonreassuring fetal status and the infant expired at approximately 45 minutes of life. Primary congenital lymphedema was confirmed via molecular testing of the vascular endothelial growth factor receptor-3 gene. Discussion. The diagnosis of PCL is suspected prenatally when ultrasound findings coincide with a positive family history of chronic lower limb lymphedema. Isolated PCL is rarely associated with significant complications. Rarely, however, widespread lymphatic dysplasia may occur, possibly resulting in nonimmune hydrops fetalis. PMID:23533860

  1. Pellucid marginal corneal degeneration.

    PubMed

    Krachmer, J H

    1978-07-01

    Pellucid marginal degeneration of the cornea is a bilateral, clear, inferior, peripheral corneal-thinning disorder. Protrusion of the cornea occurs above a band of thinning, which is located 1 to 2 mm from the limbus and measures 1 to 2 mm in width. American ophthalmologists are generally not familiar with the condition because most of the literature concerning pellucid degeneration is European. Four cases are described. This condition is differentiated from other noninflammatory cornel-thinning disorders such as keratoconus, keratoglobus, keratotorus, and posterior keratoconus. It is also differentiated from peripheral corneal disorders associated with inflammation such as Terrien's peripheral corneal degeneration, Mooren's ulcers, and ulcers from connective tissue disease.

  2. Fuchs Endothelial Corneal Dystrophy

    PubMed Central

    Elhalis, Hussain; Azizi, Behrooz; Jurkunas, Ula V.

    2011-01-01

    Fuchs endothelial corneal dystrophy (FECD) is characterized by progressive loss of corneal endothelial cells, thickening of Descement’s membrane and deposition of extracellular matrix in the form of guttae. When the number of endothelial cells becomes critically low, the cornea swells and causes loss of vision. The clinical course of FECD usually spans 10–20 years. Corneal transplantation is currently the only modality used to restore vision. Over the last several decades genetic studies have detected several genes, as well as areas of chromosomal loci associated with the disease. Proteomic studies have given rise to several hypotheses regarding the pathogenesis of FECD. This review expands upon the recent findings from proteomic and genetic studies and builds upon recent advances in understanding the causes of this common corneal disorder. PMID:20964980

  3. Corneal transplant - slideshow

    MedlinePlus

    ... ency/presentations/100082.htm Corneal transplant - series—Normal anatomy To use the sharing features on this page, ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  4. Refractive corneal surgery - discharge

    MedlinePlus

    Nearsightedness surgery - discharge; Refractive surgery - discharge; LASIK - discharge; PRK - discharge ... You had refractive corneal surgery to help improve your vision. This surgery uses a laser to reshape your cornea. It corrects mild-to-moderate nearsightedness, ...

  5. Equine corneal surgery and transplantation.

    PubMed

    Denis, Heidi M

    2004-08-01

    Corneal disease is common in equine ophthalmology and requires vigilant monitoring and appropriate therapy to optimize the outcome. Many equine corneal diseases, particularly those that progress rapidly, may benefit from surgical intervention. These include descemetoceles, deep corneal lacerations and ulcers, corneal perforation/iris prolapse, ulcerative keratitis, corneal stromal abscesses, and corneoscleral neoplasia. Indications for corneal transplantation include optical, tectonic, therapeutic, and cosmetic purposes. Corneal transplantation is most often implemented in equine patients for tectonic and therapeutic reasons when a cornea is compromised by corneal stromal abscess, iris prolapse, or neoplasia. This article provides an outline of when to consider surgical intervention for corneal disease, the procedures available and expected outcomes, and how appropriate early surgical intervention can dramatically improve the end result.

  6. Problems with corneal arcus.

    PubMed

    Fielder, A R; Winder, A F; Sheraidah, G A; Cooke, E D

    1981-01-01

    Corneal arcus presents many puzzling features. The correlation between its incidence and serum lipid levels is poor and, using immunoelectrophoresis, we have only been able to identify low-density lipoprotein inconsistently in corneae containing this deposition. Infrared thermography has shown us that arcus commences in the warmest regions of the cornea. We have considered the possible relevance of our biochemical and thermographic findings to other problems with corneal arcus such as its irreversibility, anatomical distribution, and clear zone.

  7. Central corneal abscess.

    PubMed

    van Bijsterveld, O P

    1976-05-01

    Central corneal abscess developed in the experimental animal after inoculation of biologically active staphylococcal strains in a paracentral epithelial lesion of the cornea. These abscesses did not ulcerate, developed only with high inocula, occurred more frequently in immunized rabbits. A serpiginous type of ulceration did not develop at the site of the initial epithelial lesion nor at any other place in the cornea. Histologically, the lesions consisted of densely packed polymorphonuclear leukocytes between the corneal lamellae.

  8. Effects of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell counts.

    PubMed

    Gao, Feng; Lin, Tao; Pan, Yingzhe

    2016-09-01

    Diabetic keratopathy is an ocular complication that occurs with diabetes. In the present study, the effect of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell count was investigated. One hundred and eighty diabetic patients (360 eyes) were enrolled in the study during the period from March, 2012 to March, 2013. The patients were divided into three age groups: <5, 5-10 and >10 years, with 60 patients per group (120 eyes). During the same period, 60 healthy cases (120 eyes) were selected and labeled as the normal control group. The Pentacam was used to measure the corneal optical density, and central corneal thickness. Specular microscopy was used to examine the corneal endothelial cell density. The coefficient of partial correlation was used to control age and correlate the analysis between the corneal optical density, corneal endothelial cell density, and central corneal thickness. The stage of the disease, the medial and intimal corneal optical density and central corneal thickness was analyzed in the diabetes group. The corneal optical density in the diabetes group increased compared with that of the normal control group. The medial and intimal corneal optical density and central corneal thickness were positively correlated with the course of the disease. However, the corneal endothelial cell density was not associated with the course of diabetes. There was a positive association between the medial and intimal corneal optical density and central corneal thickness of the diabetic patients. In conclusion, the results of the present study show that medial and intimal corneal optical density and central corneal thickness were sensitive indicators for early diabetic keratopathy.

  9. Effects of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell counts

    PubMed Central

    Gao, Feng; Lin, Tao; Pan, Yingzhe

    2016-01-01

    Diabetic keratopathy is an ocular complication that occurs with diabetes. In the present study, the effect of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell count was investigated. One hundred and eighty diabetic patients (360 eyes) were enrolled in the study during the period from March, 2012 to March, 2013. The patients were divided into three age groups: <5, 5–10 and >10 years, with 60 patients per group (120 eyes). During the same period, 60 healthy cases (120 eyes) were selected and labeled as the normal control group. The Pentacam was used to measure the corneal optical density, and central corneal thickness. Specular microscopy was used to examine the corneal endothelial cell density. The coefficient of partial correlation was used to control age and correlate the analysis between the corneal optical density, corneal endothelial cell density, and central corneal thickness. The stage of the disease, the medial and intimal corneal optical density and central corneal thickness was analyzed in the diabetes group. The corneal optical density in the diabetes group increased compared with that of the normal control group. The medial and intimal corneal optical density and central corneal thickness were positively correlated with the course of the disease. However, the corneal endothelial cell density was not associated with the course of diabetes. There was a positive association between the medial and intimal corneal optical density and central corneal thickness of the diabetic patients. In conclusion, the results of the present study show that medial and intimal corneal optical density and central corneal thickness were sensitive indicators for early diabetic keratopathy. PMID:27588090

  10. A corneal mold to restore normal corneal dimensions.

    PubMed

    Swinger, C A; Kornmehl, E W; York, S; Forman, J S

    1986-01-01

    A corneal mold is described that provides an MK corneal button of normal thickness and curvature from an edematous, post-mortem button. The uniform, processed tissue can then be used for experimental refractive surgery.

  11. Placental transmission of human parvovirus 4 in newborns with hydrops, Taiwan.

    PubMed

    Chen, Mao-Yuan; Yang, Shiu-Ju; Hung, Chien-Ching

    2011-10-01

    In studying the epidemiology of parvovirus 4 (PARV4) in Taiwan, we detected DNA in plasma of 3 mothers and their newborns with hydrops. In 1 additional case, only the mother had PARV4 DNA. Our findings demonstrate that PARV4 can be transmitted through the placenta.

  12. EPHB4 kinase–inactivating mutations cause autosomal dominant lymphatic-related hydrops fetalis

    PubMed Central

    Martin-Almedina, Silvia; Holdhus, Rita; Vicente, Andres; Fotiou, Elisavet; Lin, Shin; Petersen, Kjell; Simpson, Michael A.; Hoischen, Alexander; Atton, Giles; Karapouliou, Christina; Brice, Glen; Gordon, Kristiana; Wiseman, John W.; Wedin, Marianne; Rockson, Stanley G.; Jeffery, Steve; Mortimer, Peter S.; Snyder, Michael P.; Berland, Siren; Mansour, Sahar; Makinen, Taija

    2016-01-01

    Hydrops fetalis describes fluid accumulation in at least 2 fetal compartments, including abdominal cavities, pleura, and pericardium, or in body tissue. The majority of hydrops fetalis cases are nonimmune conditions that present with generalized edema of the fetus, and approximately 15% of these nonimmune cases result from a lymphatic abnormality. Here, we have identified an autosomal dominant, inherited form of lymphatic-related (nonimmune) hydrops fetalis (LRHF). Independent exome sequencing projects on 2 families with a history of in utero and neonatal deaths associated with nonimmune hydrops fetalis uncovered 2 heterozygous missense variants in the gene encoding Eph receptor B4 (EPHB4). Biochemical analysis determined that the mutant EPHB4 proteins are devoid of tyrosine kinase activity, indicating that loss of EPHB4 signaling contributes to LRHF pathogenesis. Further, inactivation of Ephb4 in lymphatic endothelial cells of developing mouse embryos led to defective lymphovenous valve formation and consequent subcutaneous edema. Together, these findings identify EPHB4 as a critical regulator of early lymphatic vascular development and demonstrate that mutations in the gene can cause an autosomal dominant form of LRHF that is associated with a high mortality rate. PMID:27400125

  13. Effect of standard-dose Betahistine on endolymphatic hydrops: an MRI pilot study.

    PubMed

    Gürkov, R; Flatz, W; Keeser, D; Strupp, M; Ertl-Wagner, B; Krause, E

    2013-03-01

    This study aimed to assess whether standard-dose Betahistine (48 mg daily) exerts an effect upon the degree of endolymphatic hydrops in patients with Menière's disease using a retrospective case series in the setting of a tertiary neurotology referral centre. In six patients with definite unilateral Menière's disease, the degree of cochlear and vestibular endolymphatic hydrops was assessed before and after treatment with a standard dose of Betahistine (48 mg daily), using high-resolution 3 T MR imaging after intratympanic contrast medium application. The treatment duration was 3-7 months (mean 5 months), and the patients were followed-up for 6-29 months (mean 11 months). In the study cohort, the standard dose of Betahistine did not have an MR morphologically measurable beneficial effect on the degree of endolymphatic hydrops. The results indicated no effect of standard-dose Betahistine on endolymphatic hydrops found on high-resolution MR imaging. Possible explanations are: (1) insufficient dosage or duration of treatment with betahistine, (2) insufficient resolution of the MR imaging technique, and (3) insufficient length of follow-up. Further studies addressing these issues are warranted.

  14. Investigation and management of non-immune fetal hydrops.

    PubMed

    Désilets, Valérie; Audibert, François

    2013-10-01

    Objectif : Décrire les moyens actuels de procéder à l’exploration et à la prise en charge de l’anasarque fœtoplacentaire non immune, en mettant l’accent sur les étiologies traitables ou récurrentes. Issues : Offrir de meilleurs services de counseling et de prise en charge en présence de cas d’anasarque non immune identifiés par diagnostic prénatal. Résultats : La littérature publiée a été récupérée par l’intermédiaire de recherches menées dans PubMed, CINAHL et The Cochrane Library en 2011 au moyen de mots clés (« non-immune hydrops fetalis », « fetal hydrops », « fetal therapy », « fetal metabolism »). Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs, aux études observationnelles et aux exposés de cas significatifs. D’autres publications ont été repérées à partir des bibliographies de ces articles. Aucune restriction n’a été appliquée en matière de date ou de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu’en mai 2012. La littérature grise (non publiée) a été identifiée par l’intermédiaire de recherches menées dans les sites Web d’organismes s’intéressant à l’évaluation des technologies dans le domaine de la santé et d’organismes connexes, dans des collections de directives cliniques, dans des registres d’essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. Avantages, désavantages et coûts : La présente directive clinique sensibilise les lecteurs aux causes de l’anasarque fœtoplacentaire non immune, ainsi qu’au diagnostic prénatal et à la prise en charge de celle-ci. Elle offre également une approche standardisée envers l’anasarque fœtoplacentaire non immune, en mettant l’accent sur la recherche de troubles pouvant être pris en charge pendant la période pr

  15. Assessment of endolymphatic hydrops and otolith function in patients with Ménière's disease.

    PubMed

    Okumura, Tomoko; Imai, Takao; Takimoto, Yasumitsu; Takeda, Noriaki; Kitahara, Tadashi; Uno, Atsuhiko; Kamakura, Takefumi; Osaki, Yasuhiro; Watanabe, Yoshiyuki; Inohara, Hidenori

    2017-03-01

    Ménière's disease is associated with hydrops of the inner ear endolymphatic space, and histopathologically, the cochlea and vestibule are usually involved. We used gadolinium-enhanced magnetic resonance imaging and measured cervical and ocular vestibular evoked myogenic potentials and the gain in the utricular induced linear vestibulo-ocular reflex to test the hypothesis that vestibular hydrops in Ménière's disease patients is associated with otolith organ dysfunction. We evaluated 21 patients diagnosed with unilateral definitive Ménière's disease using gadolinium magnetic resonance imaging to detect endolymphatic hydrops in the cochlea and vestibule. Cervical and ocular vestibular evoked myogenic potentials and the gain in utricular induced linear vestibulo-ocular reflex during eccentric rotation were measured to assess otolith organ function. For eccentric rotation, patients were rotated while displaced from the axis of rotation, while linear acceleration stimulated the utricle and induced the vestibulo-ocular reflex. Magnetic resonance imaging revealed vestibular hydrops in 14 of 20 patients (70%). Among the 14 patients, ten (71%) had abnormal cervical and three (21%) had abnormal ocular vestibular evoked myogenic potentials. Four patients (4/21, 19%) had abnormal linear vestibulo-ocular reflexes, three of whom also had abnormal ocular vestibular evoked myogenic potentials. Overall, 16 of 17 patients had normal linear vestibulo-ocular reflexes and normal ocular vestibular evoked myogenic potentials. Vestibular endolymphatic hydrops in Ménière's disease patients caused otolith organ dysfunction, mainly in the saccule. The number of Ménière's disease patients with abnormal ocular vestibular evoked myogenic potentials was low (19%), and they also had abnormal utricular induced linear vestibulo-ocular reflexes.

  16. Corneal tattooing: an alternative treatment for disfiguring corneal scars

    PubMed Central

    Pitz, S; Jahn, R; Frisch, L; Duis, A; Pfeiffer, N

    2002-01-01

    Background: The performance and results of corneal tattooing are described in a case series of 11 patients suffering from a disfiguring corneal scar using a technique similar to conventional dermatography. Methods: Drawing ink in different shades was applied into the anterior corneal stroma by punctures performed with a conventional spatula needle. Results: Up to 4 years after surgery all patients still had satisfactory staining of the formerly cosmetically disfiguring corneal scar. Conclusion: Tattooing of unsightly corneal scars proved to be an efficient and easy to perform technique, yielding acceptable results during follow up. PMID:11914207

  17. Corneal grafting and banking.

    PubMed

    Ehlers, Niels; Hjortdal, Jesper; Nielsen, Kim

    2009-01-01

    Corneal transplantation was conceptualized at the end of the 18th century, but it took more than 100 years before human corneal grafting was introduced. The greatest step forward was the demonstration by Filatov that corneal tissue can be collected and used post mortem. The history of eye banking includes the development of preservation techniques. Storage in cold to minimize microbial growth and tissue disintegration was first choice but during the last 30 years this has been taken over by warm storage (organ culture) where the donor cornea proves its sterility and vitality before being transferred to the recipient. The long-term organ culture storage makes exchange between centres possible and allows for histocompatibility matching. The internationalization led to the establishing of the European Eye Bank Association but also to an increasing number of governmental regulations. Developments in years to come may lead to control of graft biomechanics and optics. This technical development tends to favour a centralization.

  18. Treating corneal abrasions.

    PubMed

    Wingate, S

    1999-06-01

    Although corneal abrasions are commonly seen in primary care settings, the primary care literature contains scant references on detecting and managing this problem. This article provides an overview of corneal abrasion assessment and treatment. Four common etiologies of abrasion are discussed: traumatic abrasion, contact lens abrasion, foreign body abrasion, and recurrent erosion. Parameters for the history and physical examination are outlined, including sections on contact lens removal, lid eversion, and fluorescein staining. Treatment regimens for each of the etiologies are discussed, with a focus on current research on using pressure eye patches as an intervention. Indications for referral to an ophthalmologist are noted.

  19. Fetal critical aortic stenosis with natural improvement of hydrops fetalis due to spontaneous relief of severe restrictive atrial communication.

    PubMed

    Ide, Tetsuya; Miyoshi, Takekazu; Kitano, Masataka; Kurosaki, Ken-ichi; Yoshimatsu, Jun

    2015-07-01

    We describe a rare case of fetal critical aortic stenosis with spontaneous relief of severe restrictive atrial communication, resulting in complete resolution of hydrops fetalis in utero. Fetal ultrasonography showed hydrops fetalis caused by critical aortic stenosis with a severely restrictive foramen ovale and severe mitral regurgitation at 23 weeks of gestation. Hydrops fetalis, however, spontaneously resolved, showing an obvious increase of flow through the foramen ovale and pulmonary vein at 26 weeks of gestation. The neonate required balloon dilation of the aortic valve and balloon atrioseptostomy immediately after birth and also received bilateral pulmonary artery banding and arterial duct stenting 1 week later. The patient was in good condition after conversion to biventricular circulation via Ross procedure at 8 months old. The present case suggests that atrioseptostomy as a fetal intervention may improve outcome in even a hydropic condition.

  20. Diabetic corneal neuropathy.

    PubMed Central

    Schultz, R O; Peters, M A; Sobocinski, K; Nassif, K; Schultz, K J

    1983-01-01

    Corneal epithelial lesions can be found in approximately one-half of asymptomatic patients with diabetes mellitus. These lesions are transient and clinically resemble the keratopathy seen in staphylococcal keratoconjunctivitis. Staphylococcal organisms, however, can be isolated in equal percentages from diabetic patients without keratopathy. Diabetic peripheral neuropathy was found to be related to the presence of diabetic keratopathy after adjusting for age with analysis of covariance. The strongest predictor of both keratopathy and corneal fluorescein staining was vibration perception threshold in the toes (P less than 0.01); and the severity of keratopathy was directly related to the degree of diminution of peripheral sensation. Other predictors of keratopathy were: reduced tear breakup time (P less than 0.03), type of diabetes (P less than 0.01), and metabolic status as indicated by c-peptide fasting (P less than 0.01). No significant relationships were found between the presence of keratopathy and tear glucose levels, endothelial cell densities, corneal thickness measurements, the presence of S epidermidis, or with duration of disease. It is our conclusion that asymptomatic epithelial lesions in the nontraumatized diabetic cornea can occur as a manifestation of generalized polyneuropathy and probably represent a specific form of corneal neuropathy. Images FIGURE 1 FIGURE 2 FIGURE 3 PMID:6676964

  1. Corneal biomechanical properties from air-puff corneal deformation imaging

    NASA Astrophysics Data System (ADS)

    Marcos, Susana; Kling, Sabine; Bekesi, Nandor; Dorronsoro, Carlos

    2014-02-01

    The combination of air-puff systems with real-time corneal imaging (i.e. Optical Coherence Tomography (OCT), or Scheimpflug) is a promising approach to assess the dynamic biomechanical properties of the corneal tissue in vivo. In this study we present an experimental system which, together with finite element modeling, allows measurements of corneal biomechanical properties from corneal deformation imaging, both ex vivo and in vivo. A spectral OCT instrument combined with an air puff from a non-contact tonometer in a non-collinear configuration was used to image the corneal deformation over full corneal cross-sections, as well as to obtain high speed measurements of the temporal deformation of the corneal apex. Quantitative analysis allows direct extraction of several deformation parameters, such as apex indentation across time, maximal indentation depth, temporal symmetry and peak distance at maximal deformation. The potential of the technique is demonstrated and compared to air-puff imaging with Scheimpflug. Measurements ex vivo were performed on 14 freshly enucleated porcine eyes and five human donor eyes. Measurements in vivo were performed on nine human eyes. Corneal deformation was studied as a function of Intraocular Pressure (IOP, 15-45 mmHg), dehydration, changes in corneal rigidity (produced by UV corneal cross-linking, CXL), and different boundary conditions (sclera, ocular muscles). Geometrical deformation parameters were used as input for inverse finite element simulation to retrieve the corneal dynamic elastic and viscoelastic parameters. Temporal and spatial deformation profiles were very sensitive to the IOP. CXL produced a significant reduction of the cornea indentation (1.41x), and a change in the temporal symmetry of the corneal deformation profile (1.65x), indicating a change in the viscoelastic properties with treatment. Combining air-puff with dynamic imaging and finite element modeling allows characterizing the corneal biomechanics in-vivo.

  2. Antenatal diagnosis of large sacro-coccygeal teratoma with foetal cardiomegaly and hydrops.

    PubMed

    Gupta, N; Shah, D; Singh, U; Tiwari, A

    2008-01-01

    We report the case of a young primigravida who presented with a 20 weeks pregnancy with a previous diagnosis of uterine fibroid. However, ultrasound evaluation revealed the presence of a large sacro-coccygeal teratoma in the foetus which was heterogeneous with cystic areas and calcific foci, and showed increased vascularity. There was also evidence of foetal cardiomegaly and hydrops foetalis, indicated by subcutaneous oedema in the foetus,thickened placenta and polyhydramnios. The presence of hydrops with sacro-coccygeal teratoma has a grave prognosis for the mother and child; hence termination of pregnancy was done. A 20 weeks old foetus with a huge sacro-coccygeal mass, which was ruptured at many places and showed areas of active bleed, was expelled.

  3. Case of a healthy infant born following antenatal enterovirus myocarditis and hydrops.

    PubMed

    Bonnin, Aurore; Tassin, Mikael; Vauloup-Fellous, Christelle; Letamendia, Emmanuelle; Stos, Bertrand; Bonnet, Damien; Gajdos, Vincent; Mabille, Mylène; Benachi, Alexandra

    2014-11-01

    Fetal hydrops and myocarditis were diagnosed in a woman at 32 weeks of gestation (WG). Transplacental enterovirus infection was suspected because all other causes of myocarditis and hydrops were excluded, it was during an endemic period, and there was a setting of maternal infection (fever a few days before). We opted for in utero treatment because of the risk of resuscitating a neonate with myocarditis and hydrops. We administered dexamethasone 12mg twice for pulmonary maturation and presumed it would partially improve the myocarditis. Fetal arrhythmia was noted at 35 WG and we decided to deliver the infant as postnatal treatment of the heart disorder would be more effective. RT-PCR (ARGENE(®)) showed that the neonate's throat and anal tissues and cord blood sampled on the day of birth contained enterovirus ribonucleic acid and coxsackievirus B5, as did the mother's anal sample. Laboratory tests, heart MRI and probably brain MRI indicated neonatal enterovirus infection. Findings were normal at two-year follow-up.

  4. Diagnostic Value of Vestibular Evoked Myogenic Potentials in Endolymphatic Hydrops: A Meta-Analysis

    PubMed Central

    Zhang, Sulin; Leng, Yangming; Liu, Bo; Shi, Hao; Lu, Meixia; Kong, Weijia

    2015-01-01

    In this study, we evaluated the clinical diagnostic value of vestibular evoked myogenic potentials (VEMPs) for endolymphatic hydrops (EH) by systematic review and Meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under summary receiver operating characteristic curves (AUC) were calculated. Subgroup analysis and publication bias assessment were also conducted. The pooled sensitivity and the specificity were 49% (95% CI: 46% to 51%) and 95% (95% CI: 94% to 96%), respectively. The pooled positive likelihood ratio was 18.01 (95% CI: 9.45 to 34.29) and the pooled negative likelihood ratio was 0.54 (95% CI: 0.47 to 0.61). AUC was 0.78 and the pooled diagnostic odds ratio of VEMPs was 39.89 (95% CI: 20.13 to 79.03). In conclusion, our present meta-analysis has demonstrated that VEMPs test alone is not sufficient for Meniere’s disease or delayed endolymphatic hydrops diagnosis, but that it might be an important component of a test battery for diagnosing Meniere’s disease or delayed endolymphatic hydrops. Moreover, VEMPs, due to its high specificity and non-invasive nature, might be used as a screening tool for EH. PMID:26455332

  5. Corneal Hydration Control in Fuchs' Endothelial Corneal Dystrophy

    PubMed Central

    Wacker, Katrin; McLaren, Jay W.; Kane, Katrina M.; Baratz, Keith H.; Patel, Sanjay V.

    2016-01-01

    Purpose To assess corneal hydration control across a range of severity of Fuchs' endothelial corneal dystrophy (FECD) by measuring the percent recovery per hour (PRPH) of central corneal thickness after swelling the cornea and to determine its association with corneal morphologic parameters. Methods Twenty-three corneas of 23 phakic FECD patients and 8 corneas of 8 healthy control participants devoid of guttae were graded (modified Krachmer scale). Effective endothelial cell density (ECDe) was determined from the area of guttae and local cell density in confocal microscopy images. Steady-state corneal thickness (CTss) and standardized central corneal backscatter were derived from Scheimpflug images. Corneal swelling was induced by wearing a low-oxygen transmissible contact lens for 2 hours in the morning. De-swelling was measured over 5 hours after lens removal or until corneal thickness returned to CTss. Percent recovery per hour was 100 × (1 – e−k), where k was determined from CT(t) = (de−kt) + CTss, and where d was the initial change from CTss. Results After contact lens wear, corneas swelled by 9% (95% CI 9–10). Percent recovery per hour was 49%/h (95% CI 41–57) in controls and 37%/h in advanced FECD (95% CI 29–43, P = 0.028). Low PRPH was associated with disease severity, low ECDe, and increased anterior and posterior corneal backscatter. Anterior backscatter was associated with PRPH in a multivariable model (R2 = 0.44). Conclusions Corneal hydration control is impaired in advanced FECD and is inversely related to anterior corneal backscatter. Anterior corneal backscatter might serve as an indicator of impaired endothelium in FECD. PMID:27661858

  6. Nanomedicine Approaches for Corneal Diseases

    PubMed Central

    Chaurasia, Shyam S.; Lim, Rayne R.; Lakshminarayanan, Rajamani; Mohan, Rajiv R.

    2015-01-01

    Corneal diseases are the third leading cause of blindness globally. Topical nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, antibiotics and tissue transplantation are currently used to treat corneal pathological conditions. However, barrier properties of the ocular surface necessitate high concentration of the drugs applied in the eye repeatedly. This often results in poor efficacy and several side-effects. Nanoparticle-based molecular medicine seeks to overcome these limitations by enhancing the permeability and pharmacological properties of the drugs. The promise of nanomedicine approaches for treating corneal defects and restoring vision without side effects in preclinical animal studies has been demonstrated. Numerous polymeric, metallic and hybrid nanoparticles capable of transporting genes into desired corneal cells to intercept pathologic pathways and processes leading to blindness have been identified. This review provides an overview of corneal diseases, nanovector properties and their applications in drug-delivery and corneal disease management. PMID:25941990

  7. Computational Model for Corneal Transplantation

    NASA Astrophysics Data System (ADS)

    Cabrera, Delia

    2003-10-01

    We evaluated the refractive consequences of corneal transplants using a biomechanical model with homogeneous and inhomogeneous Young's modulus distributions within the cornea, taking into account ablation of some stromal tissue. A FEM model was used to simulate corneal transplants in diseased cornea. The diseased cornea was modeled as an axisymmetric structure taking into account a nonlinearly elastic, isotropic formulation. The model simulating the penetrating keratoplasty procedure gives more change in the postoperative corneal curvature when compared to the models simulating the anterior and posterior lamellar graft procedures. When a lenticle shaped tissue was ablated in the graft during the anterior and posterior keratoplasty, the models provided an additional correction of about -3.85 and -4.45 diopters, respectively. Despite the controversy around the corneal thinning disorders treatment with volume removal procedures, results indicate that significant changes in corneal refractive power could be introduced by a corneal transplantation combined with myopic laser ablation.

  8. Cryopreservation for corneal storage.

    PubMed

    Armitage, W John

    2009-01-01

    Currently, cryopreservation is the only method that offers the prospect of truly long-term storage of living cells and tissues. Despite some successful cryopreserved corneal grafts, freezing has been shown to damage the endothelium. When isolated cells are frozen, there are two principal mechanisms of damage: intracellular freezing, which occurs at high cooling rates, and solution effect injury at low cooling rates. When tissues are frozen, there are additional factors that appear to render cells more susceptible to intracellular freezing. Lower cooling rates appear to overcome this when freezing cornea. Vitrification is a way of achieving ice-free cryopreservation, but it also poses considerable challenges owing to the very high solute concentrations required to achieve vitrification at practicable cooling rates. Encouraging results have also been reported for cornea frozen using non-permeating cryoprotectants, which could lead to simpler methods of corneal cryopreservation.

  9. Keratomycosis in corneal sepsis.

    PubMed

    Sharma, S L; Bajaj, R; Sharma, R

    1987-01-01

    510 cases of corneal ulceration were studied for the presence of fungus as a causative organism. Fungus was found in 87 (17.5%) most common fungus found was aspergillus. Mucor was found in 16 cases (18.1%) which is higher than earlier reports. History of trauma specially with vegetative matter and the application of steriods for one purpose or the other is a factor of importance as noted in this study.

  10. What is Menière's disease? A contemporary re-evaluation of endolymphatic hydrops.

    PubMed

    Gürkov, R; Pyykö, I; Zou, J; Kentala, E

    2016-04-01

    Menière's disease is a chronic condition with a prevalence of 200-500 per 100,000 and characterized by episodic attacks of vertigo, fluctuating hearing loss, tinnitus, aural pressure and a progressive loss of audiovestibular functions. Over 150 years ago, Prosper Menière was the first to recognize the inner ear as the site of lesion for this clinical syndrome. Over 75 years ago, endolymphatic hydrops was discovered as the pathologic correlate of Menière's disease. However, this pathologic finding could be ascertained only in post-mortem histologic studies. Due to this diagnostic dilemma and the variable manifestation of the various audiovestibular symptoms, diagnostic classification systems based on clinical findings have been repeatedly modified and have not been uniformly used in scientific publications on Menière's disease. Furthermore, the higher level measures of impact on quality of life such as vitality and social participation have been neglected hitherto. Recent developments of high-resolution MR imaging of the inner ear have now enabled us to visualize in vivo endolymphatic hydrops in patients with suspected Menière's disease. In this review, we summarize the existing knowledge from temporal bone histologic studies and from the emerging evidence on imaging-based evaluation of patients with suspected Menière's disease. These indicate that endolymphatic hydrops is responsible not only for the full-blown clinical triad of simultaneous attacks of auditory and vestibular dysfunction, but also for other clinical presentations such as "vestibular" and "cochlear Menière's disease". As a consequence, we propose a new terminology which is based on symptomatic and imaging characteristics of these clinical entities to clarify and simplify their diagnostic classification.

  11. Semi-Quantitative vs. Volumetric Determination of Endolymphatic Space in Menière’s Disease Using Endolymphatic Hydrops 3T-HR-MRI after Intravenous Gadolinium Injection

    PubMed Central

    Homann, Georg; Vieth, Volker; Weiss, Daniel; Nikolaou, Konstantin; Heindel, Walter; Notohamiprodjo, Mike; Böckenfeld, Yvonne

    2015-01-01

    Magnetic resonance imaging enhances the clinical diagnosis of Menière's disease. This is accomplished by in vivo detection of endolymphatic hydrops, which are graded using different semi-quantitative grading systems. We evaluated an established, semi-quantitative endolymphatic hydrops score and with a quantitative method for volumetric assessment of the endolymphatic size. 11 patients with Menière's disease and 2 healthy subjects underwent high resolution endolymphatic hydrops 3 Tesla MRI with highly T2 weighted FLAIR and T2DRIVE sequences. The degree of endolymphatic hydrops was rated semi-quantitatively and compared to the results of 3D-volumetry. Moreover, the grade of endolymphatic hydrops was correlated with pure tone audiometry. Semi-quantitative grading and volumetric evaluation of the endolymphatic hydrops are in accordance (r = 0.92) and the grade of endolymphatic hydrops correlates with pure tone audiometry. Patients with a sickness duration of ≥ 30 months showed a significant higher total labyrinth fluid volume (p = 0.03). Fast, semi-quantitative evaluation of endolymphatic hydrops is highly reliable compared to quantitative/volumetric assessment. Endolymphatic space is significantly higher in patients with longer sickness duration. PMID:25768940

  12. [The causes of necrobiosis and apoptosis of corneal epithelial cells during primary acquired keratoconus].

    PubMed

    Ziangirova, G G; Antonova, O V

    2002-01-01

    We studied 56 biopsy samples of conjunctiva and 50 corneal discs excised from 28 patients with acquired keratoconus cornea. The conjunctivas in all biopsy samples showed various stages of immune inflammation. Necrobiotic changes have been revealed in epithelium of the corneal discs going by the pathways of apoptosis--programmed cell death--and oncosis--initial edematic stage of necrobiosis. At the stage of acute inflammation they are due to cytotoxic effect of the lymphocytes, monocytes, and macrophages. Antibody-dependent cytotoxicity mediated by plasma and lymphoid cells predominates at this stage. At the reparative stage of inflammation ischemia, an inductor of apoptosis and oncosis, underlies necrobiotic changes in corneal epithelium.

  13. Corneal structure and transparency

    PubMed Central

    Meek, Keith M.; Knupp, Carlo

    2015-01-01

    The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

  14. [Anomalies in the development of the sinus venosus as a probable cause of heart rhythm disorders and fetal hydrops].

    PubMed

    Dudorkinová, D; Povýsilová, V; Skovránek, J

    1993-09-01

    Prenatal ultrasonic examination during the 28th week of gestation revealed a transient disorder of the cardiac rhythm in the foetus. Subsequently repeated echocardiographic examinations confirmed foetal hydrops which together with signs of EP gestosis of the mother was an indication to terminate pregnancy during the 29th week by Caesarean section. In the severely hydropic male foetus in the enlarged anterior wall of the right atrium an atypical vascular canal was found which was in the close vicinity of the sinoatrial node. The latter most probably caused intermittent intrauterine supraventricular tachycardia in a heart with a normal configuration in other respects.

  15. Tissue Engineering of Corneal Endothelium

    PubMed Central

    Mimura, Tatsuya; Yokoo, Seiichi; Yamagami, Satoru

    2012-01-01

    Human corneal endothelial cells (HCECs) do not replicate after wounding. Therefore, corneal endothelial deficiency can result in irreversible corneal edema. Descemet stripping automated endothelial keratoplasty (DSAEK) allows selective replacement of the diseased corneal endothelium. However, DSAEK requires a donor cornea and the worldwide shortage of corneas limits its application. This review presents current knowledge on the tissue engineering of corneal endothelium using cultured HCECs. We also provide our recent work on tissue engineering for DSAEK grafts using cultured HCECs. We reconstructed DSAEK grafts by seeding cultured DiI-labelled HCECs on collagen sheets. Then HCEC sheets were transplanted onto the posterior stroma after descemetorhexis in the DSAEK group. Severe stromal edema was detected in the control group, but not in the DSAEK group throughout the observation period. Fluorescein microscopy one month after surgery showed numerous DiI-labelled cells on the posterior corneal surface in the DSAEK group. Frozen sections showed a monolayer of DiI-labelled cells on Descemet’s membrane. These findings indicate that cultured adult HCECs, transplanted with DSAEK surgery, maintain corneal transparency after transplantation and suggest the feasibility of performing DSAEK with HCECs to treat endothelial dysfunction. PMID:24955745

  16. Corneal blindness: a global perspective.

    PubMed Central

    Whitcher, J. P.; Srinivasan, M.; Upadhyay, M. P.

    2001-01-01

    Diseases affecting the cornea are a major cause of blindness worldwide, second only to cataract in overall importance. The epidemiology of corneal blindness is complicated and encompasses a wide variety of infectious and inflammatory eye diseses that cause corneal scarring, which ultimately leads to functional blindness. In addition, the prevalence of corneal disease varies from country to country and even from one population to another. While cataract is responsible for nearly 20 million of the 45 million blind people in the world, the next major cause is trachoma which blinds 4.9 million individuals, mainly as a result of corneal scarring and vascularization. Ocular trauma and corneal ulceration are significant causes of corneal blindness that are often underreported but may be responsible for 1.5-2.0 million new cases of monocular blindness every year. Causes of childhood blindness (about 1.5 million worldwide with 5 million visually disabled) include xerophthalmia (350,000 cases annually), ophthalmia neonatorum, and less frequently seen ocular diseases such as herpes simplex virus infections and vernal keratoconjunctivitis. Even though the control of onchocerciasis and leprosy are public health success stories, these diseases are still significant causes of blindness--affecting a quarter of a million individuals each. Traditional eye medicines have also been implicated as a major risk factor in the current epidemic of corneal ulceration in developing countries. Because of the difficulty of treating corneal blindness once it has occurred, public health prevention programmes are the most cost-effective means of decreasing the global burden of corneal blindness. PMID:11285665

  17. Management of advanced corneal ectasias.

    PubMed

    Maharana, Prafulla K; Dubey, Aditi; Jhanji, Vishal; Sharma, Namrata; Das, Sujata; Vajpayee, Rasik B

    2016-01-01

    Corneal ectasias include a group of disorders characterised by progressive thinning, bulging and distortion of the cornea. Keratoconus is the most common disease in this group. Other manifestations include pellucid marginal degeneration, Terrien's marginal degeneration, keratoglobus and ectasias following surgery. Advanced ectasias usually present with loss of vision due to high irregular astigmatism. Management of these disorders is difficult due to the peripheral location of ectasia and associated severe corneal thinning. Newer contact lenses such as scleral lenses are helpful in a selected group of patients. A majority of these cases requires surgical intervention. This review provides an update on the current treatment modalities available for management of advanced corneal ectasias.

  18. Cyanoacrylates and corneal abrasion.

    PubMed

    Dean, B S; Krenzelok, E P

    1989-01-01

    Cyanoacrylate-containing adhesives such as Super Glue, Krazy Glue, and a vast array of artificial nail adhesives are monomers which rapidly polymerize and bond in the presence of water or weak bases. Inadvertent contact with skin or tissue can also cause rapid bonding with resultant irritation. To assess the magnitude of problems associated with ocular contamination involving cyanoacrylates, a 12-month prospective study was conducted. 34 cases (21 adult and 13 pediatric) were collected. In all cases, contaminated eyes were thoroughly irrigated with tepid water for 15 minutes. 15 patients (44%) suffered a corneal abrasion, as determined by ophthalmic exam, necessitating treatment with antibiotics, cycloplegics, and patching. Individuals reporting complete resolution were irrigated with 20 minutes of exposure, while patients suffering mechanical injury delayed decontamination for a minimum of 15 minutes. In addition to immediate irrigation of eyes exposed to cyanoacrylates, we recommend an ophthalmologic evaluation to rule out the possibility of mechanical injury.

  19. Hydrops fetalis

    MedlinePlus

    ... condition in which mother who has Rh negative blood type makes antibodies to her baby's Rh positive blood ... of red blood cells that match the infant's blood type. An exchange transfusion to rid the baby's body ...

  20. Corneal Collagen Cross-Linking

    PubMed Central

    Jankov II, Mirko R.; Jovanovic, Vesna; Nikolic, Ljubisa; Lake, Jonathan C.; Kymionis, Georgos; Coskunseven, Efekan

    2010-01-01

    Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A (UVA) is a new technique of corneal tissue strengthening by using riboflavin as a photosensitizer and UVA to increase the formation of intra and interfibrillar covalent bonds by photosensitized oxidation. Keratocyte apoptosis in the anterior segment of the corneal stroma all the way down to a depth of about 300 microns has been described and a demarcation line between the treated and untreated cornea has been clearly shown. It is important to ensure that the cytotoxic threshold for the endothelium has not been exceeded by strictly respecting the minimal corneal thickness. Confocal microscopy studies show that repopulation of keratocytes is already visible 1 month after the treatment, reaching its pre-operative quantity and quality in terms of functional morphology within 6 months after the treatment. The major indication for the use of CXL is to inhibit the progression of corneal ectasias, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photoablation. This treatment has also been used to treat infectious corneal ulcers with apparent favorable results. Combination with other treatments, such as intracorneal ring segment implantation, limited topography-guided photoablation and conductive keratoplasty have been used with different levels of success. PMID:20543933

  1. Intrastromal Corneal Ring Implants for Corneal Thinning Disorders

    PubMed Central

    2009-01-01

    Executive Summary Objective The purpose of this project was to determine the role of corneal implants in the management of corneal thinning disease conditions. An evidence-based review was conducted to determine the safety, effectiveness and durability of corneal implants for the management of corneal thinning disorders. The evolving directions of research in this area were also reviewed. Subject of the Evidence-Based Analysis The primary treatment objectives for corneal implants are to normalize corneal surface topography, improve contact lens tolerability, and restore visual acuity in order to delay or defer the need for corneal transplant. Implant placement is a minimally invasive procedure that is purported to be safe and effective. The procedure is also claimed to be adjustable, reversible, and both eyes can be treated at the same time. Further, implants do not limit the performance of subsequent surgical approaches or interfere with corneal transplant. The evidence for these claims is the focus of this review. The specific research questions for the evidence review were as follows: Safety Corneal Surface Topographic Effects: Effects on corneal surface remodelling Impact of these changes on subsequent interventions, particularly corneal transplantation (penetrating keratoplasty [PKP]) Visual Acuity Refractive Outcomes Visual Quality (Symptoms): such as contrast vision or decreased visual symptoms (halos, fluctuating vision) Contact lens tolerance Functional visual rehabilitation and quality of life Patient satisfaction: Disease Process: Impact on corneal thinning process Effect on delaying or deferring the need for corneal transplantation Clinical Need: Target Population and Condition Corneal ectasia (thinning) comprises a range of disorders involving either primary disease conditions such as keratoconus and pellucid marginal corneal degeneration or secondary iatrogenic conditions such as corneal thinning occurring after LASIK refractive surgery. The condition

  2. An Unusual Hydrops Fetalis Associated with Compound Heterozygosity for Krüppel-like Factor 1 mutations.

    PubMed

    Lee, Helena H L; Mak, Annisa S L; Kou, K O; Poon, C F; Wong, W S; Chiu, K H; Au, Patrick K C; Chan, Kelvin Y K; Kan, Anita S Y; Tang, Mary H Y; Leung, K Y

    2016-11-01

    Hydrops fetalis is commonly due to Hb Bart's (γ4) disease in South East Asia. Here, we report an unusual case of hydrops fetalis due to congenital dyserythropoietic anemia (CDA) associated with compound heterozygosity for Krüppel-like factor 1 (KLF1) gene mutations. Fetal cardiomegaly was first detected on routine mid-trimester scan in a pregnant woman with normal mean corpuscular volume (MCV) and Rhesus positive status. The fetus subsequently developed hydrops fetalis, and cordocentesis showed severe fetal anemia with a hemoglobin (Hb) level of 3.4 g/dL. Common causes of fetal anemia including Hb Bart's disease, parvovirus infection, and red cell antibodies were excluded. In view of the marked increase in erythroblasts at various stages of erythropoiesis, the diagnosis of CDA was suspected. We screened the couple for previously reported KLF1 gene mutations, showing that the mother was heterozygous for the c.525_526insCGGCGCC, p.Gly176Argfs*179 mutation, and her husband heterozygous for c.1012C>A, p.Pro338Thr mutation. The fetus was a compound heterozygote for these two KLF1 mutations. After counseling, repeated intrauterine transfusions were given at 27, 29, and 34 weeks' gestation; the hydrops fetalis was resolved. The baby was delivered at 34 weeks' gestation and required monthly blood transfusions but was otherwise thriving. Bone marrow aspiration at 10 months of age showed the features of ineffective erythropoiesis, compatible with CDA. In conclusion, hydrops fetalis can rarely be due to CDA associated with a compound heterozygous mutation for KLF1 gene mutations, and be managed by repeated intrauterine transfusions. Our present report adds to the wide clinical spectrum of KLF1 mutations.

  3. The use of xenologous amniotic membrane to repair canine corneal perforation created by penetrating keratectomy.

    PubMed

    Barros, P.S.M.; Garcia, J.A.; Laus, J.L.; Ferreira, A.L.; Salles Gomes, T.L.

    1998-01-01

    This study was performed to evaluate the use of glycerol-preserved equine amniotic membrane as replacement for full-thickness corneal defects in dogs. Eighteen mixed-breed dogs were used. A perilimbal, full-thickness, 5 mm square corneal defect was created surgically, and a donor implant of equine amniotic membrane of the same size and shape sutured in place with 10-0 nylon simple interrupted sutures. Corneal edema was observed near the implant 24 h after surgery, but was absent after 1 week. Granulation tissue and corneal vascularization superficial to the implant were noticed on postoperative day 7, but were absent on day 30. Corneal vascularization persisted until the end of the experiment. There was no fluorescein retention by postoperative day 30. There was slight clearing of the corneal implant by postoperative 30, and slight pigmentation of the donor implant observed at postoperative day 180. An acute inflammatory process as well as fibroblasts were present at early postoperative stages. At postoperative day 60 there was no inflammatory cellular infiltrate, but fibroblasts and fibrosis were present. Corneal architecture was restored at the end of the experiment, with a layering of the epithelium-stroma-debris of amniotic membrane-stroma-endothelium present, and pigmentation and vascularization present in the deep layers of the cornea. Although vascularization indicated some degree of graft rejection, the clinical and histological evidence indicates that the xenologous amniotic membrane can be useful as a tectonic graft in the repair of full-thickness lesions of the cornea of dogs.

  4. Ultrastructural Analysis of in vivo Expanded Corneal Epithelium on Amniotic Membrane

    PubMed Central

    Ha, Hyo Shin; Song, Kye Yong

    2006-01-01

    The purpose of this study is to characterize and compare the ultrastructural changes occurring during the in vivo cultivation of corneal epithelium on amniotic membrane (AM) at several different time points. Corneal burn patients (n=7) with a corneal epithelial defect and severe limbal damage were selected. Initially, AM transplantation with limbal autograft was performed at the acute stage of corneal burn to reconstruct the damaged ocular surface. One to six (mean interval; 3.3±1.2) months later, the central part of AM containing an in vivo expanded corneal epithelium was excised and retransplanted in adjacent lesions. The excised epithelium with AM was examined by electron microscopy and immunohistochemical study. By electron microscopy, one and two months after expansion, cultivated epithelium on AM showed an undifferentiated epithelium and an incomplete basement membrane (BM). But, after three months, the cultivated epithelium began to differentiate into a multilayered epithelium with a continuous BM with increased hemidesmosomes. These findings were further confirmed by immunohistochemical study, that cytokeratin K3 was expressed in the cultivated corneal epithelium and newly formed BM was partially positive of collagen IV at three months. At least 3 months may be needed for the proliferation and differentiation of in vivo cultivated corneal epithelium on AM. PMID:16778403

  5. Evaluation of Factors Limiting Corneal Donation.

    PubMed

    Röck, Daniel; Wude, Johanna; Yoeruek, Efdal; Bartz-Schmidt, Karl Ulrich; Röck, Tobias

    2016-11-15

    BACKGROUND This study aimed to investigate factors limiting corneal donation at the University Hospital Tübingen. MATERIAL AND METHODS We retrospectively studied all hospital deaths from January 2012 to December 2015, considering each deceased patient as a potential corneal donor. During this period an ophthalmic resident managed corneal donor procurement on a full-time basis. Various factors limiting corneal donation were examined. RESULTS Among the 3412 deaths, 2937 (86.1%) displayed nonfulfillment of corneal donation. Consent for corneal donation was obtained in 475 cases (13.9%). The mean annual corneal donation rate was 13.9 donors per 100 deaths (range: 11.2-17.8). The leading causes of nonfulfillment of corneal donations were refusal to donate (49.8%, 1698 cases) and medical contraindications (23.6%, 805 cases). After next-of-kin interview of 2173 potential donors (109 potential donors were excluded because of logistical problems), willingness to participate in corneal donation was present in 475 cases (21.9%), whereas in 1698 cases (78.1%) corneal donation was refused. CONCLUSIONS Our study showed refusal to donate is the most important factor limiting corneal donation. It seems that increasing the knowledge of people about corneal donation through public education and media are necessary to address the corneal shortage.

  6. Jumping translocation in a newborn boy with dup(4q) and severe hydrops fetalis

    SciTech Connect

    Duval, E.; Enden, A. van den; Vanhaesebrouck, P.; Speleman, F.

    1994-08-15

    We report on the unusual cytogenetic findings in a newborn boy with severe hydrops fetalis. He has a mosaic for 2 unbalanced chromosome rearrangements: a der(18)t(4;18)(q31;q23) and a der(18)t(4;18)(q31;p11). As a result, this patient had a duplication of 4q31-qter in cells, and was possibly monosomic for the distal ends of 18p and 18q, respectively in the 2 cell lines. Sine in both rearrangements the same chromosome 4 segment was translocated to 2 different chromosome regions, we consider the present finding as a peculiar type of jumping translocation. 32 refs., 3 figs., 1 tab.

  7. Corneal Biomechanical Findings in Contact Lens Induced Corneal Warpage

    PubMed Central

    Letafatnejad, Mojgan; Beheshtnejad, Amir Hooshang; Ghaffary, Seyed Reza; Hassanpoor, Narges; Yaseri, Mehdi

    2016-01-01

    Purpose. To evaluate the difference in biomechanical properties between contact lens induced corneal warpage and normal and keratoconic eyes. Method. Prospective observational case control study, where 94 eyes of 47 warpage suspicious and 46 eyes of 23 keratoconic patients were included. Warpage suspected cases were followed until a definite diagnosis was made (warpage, normal, or keratoconus). Results. 44 eyes of 22 patients had contact lens related corneal warpage. 46 eyes of 23 people were diagnosed as nonwarpage normal eyes. 46 eyes of 23 known keratoconus patients were included for comparison. The mean age of the participants was 23.8 ± 3.8 years, and 66.2% of the subjects were female. The demographic and refractive data were not different between warpage and normal groups but were different in the keratoconus group. The biomechanical properties (corneal hysteresis or CH and corneal resistance factor or CRF) were different with the highest value in the warpage group followed by normal and keratoconus groups. CRF was 10.08 ± 1.75, 9.23 ± 1.22, and 7.38 ± 2.14 and CH was 10.21 ± 1.57, 9.59 ± 1.21, and 8.69 ± 2.34 in the warpage, normal, and keratoconus groups, respectively. Conclusion. Corneal biomechanics may be different in people who develop contact lens induced warpage. PMID:27688908

  8. NK cells modulate the inflammatory response to corneal epithelial abrasion and thereby support wound healing.

    PubMed

    Liu, Qiong; Smith, C Wayne; Zhang, Wanyu; Burns, Alan R; Li, Zhijie

    2012-08-01

    Natural killer (NK) cells are lymphocytes of the innate immune system that have crucial cytotoxic and regulatory roles in adaptive immunity and inflammation. Herein, we consider a role for these cells in corneal wound healing. After a 2-mm central epithelial abrasion of the mouse cornea, a subset of classic NK cells migrated into the limbus and corneal stroma, peaking at 24 hours with an eightfold increase over baseline. Depletion of γδ T cells significantly reduced NK cell accumulation (>70%; P < 0.01); however, in neutrophil-depleted animals, NK cell influx was normal. Isolated spleen NK cells migrated to the wounded cornea, and this migration was reduced by greater than 60% (P < 0.01) by ex vivo antibody blocking of NK cell CXCR3 or CCR2. Antibody-induced depletion of NK cells significantly altered the inflammatory reaction to corneal wounding, as evidenced by a 114% increase (P < 0.01) in neutrophil influx at a time when acute inflammation is normally waning. Functional blocking of NKG2D, an activating receptor for NK cell cytotoxicity and cytokine secretion, did not inhibit NK cell immigration, but significantly increased neutrophil influx. Consistent with excessive neutrophil accumulation, NK depletion and blocking of NKG2D also inhibited corneal nerve regeneration and epithelial healing (P < 0.01). Findings of this study suggest that NK cells are actively involved in corneal healing by limiting the innate acute inflammatory reaction to corneal wounding.

  9. Substrates for Expansion of Corneal Endothelial Cells towards Bioengineering of Human Corneal Endothelium

    PubMed Central

    Navaratnam, Jesintha; Utheim, Tor P.; Rajasekhar, Vinagolu K.; Shahdadfar, Aboulghassem

    2015-01-01

    Corneal endothelium is a single layer of specialized cells that lines the posterior surface of cornea and maintains corneal hydration and corneal transparency essential for vision. Currently, transplantation is the only therapeutic option for diseases affecting the corneal endothelium. Transplantation of corneal endothelium, called endothelial keratoplasty, is widely used for corneal endothelial diseases. However, corneal transplantation is limited by global donor shortage. Therefore, there is a need to overcome the deficiency of sufficient donor corneal tissue. New approaches are being explored to engineer corneal tissues such that sufficient amount of corneal endothelium becomes available to offset the present shortage of functional cornea. Although human corneal endothelial cells have limited proliferative capacity in vivo, several laboratories have been successful in in vitro expansion of human corneal endothelial cells. Here we provide a comprehensive analysis of different substrates employed for in vitro cultivation of human corneal endothelial cells. Advances and emerging challenges with ex vivo cultured corneal endothelial layer for the ultimate goal of therapeutic replacement of dysfunctional corneal endothelium in humans with functional corneal endothelium are also presented. PMID:26378588

  10. Kabuki syndrome as a cause of non-immune fetal hydrops/ascites.

    PubMed

    Long, Ashleigh; Sinkovskaya, Elena S; Edmondson, Andrew C; Zackai, Elaine; Schrier Vergano, Samantha A

    2016-12-01

    Kabuki syndrome (MIM 147920) is a well-described, multiple congenital anomaly syndrome characterized by growth and developmental delay, cardiac, renal, and vertebral anomalies, as well as persistent fetal finger pads and distinct facial features. Facies are characterized by long palpebral fissures with eversion of lateral third of the lower eyelid, resembling the "Kabuki make-up" theatre genre after which the syndrome is named. Kabuki syndrome is estimated to affect 1/32,000 births, with 55-80% of patients showing nonsense or frameshift mutations in the KMT2D (MLL2) gene, which encodes a histone transferase located on chromosome 12q. Additionally, owing to the heterogeneous nature of Kabuki syndrome, a smaller number of diagnosed patients have been identified with mutations or deletions in KDM6A (a component of the same transcriptional complex as KMT2D) with no mutations in KMT2D, or as those diagnosed with Kabuki syndrome and without alterations in either KMT2D or KDM6A. Diagnosis of the syndrome in newborns and infants is difficult, as the facial features are not as evident as in toddler- or childhood. There are no known "tell-tale" signs of Kabuki syndrome prenatally, and there are no reports of common, specific findings in fetuses that might suggest the diagnosis. We present here two infants who presented with prenatal hydrops/ascites, who were subsequently diagnosed with Kabuki syndrome. Although relatively non-specific, we suggest that Kabuki syndrome be added to the list of genetic syndromes that are suspected in cases of prenatal hydrops, review the molecular etiology of Kabuki syndrome, and broaden the phenotype of this well-described disorder. © 2016 Wiley Periodicals, Inc.

  11. Otolithic Membrane Damage in Patients with Endolymphatic Hydrops and Drop Attacks

    PubMed Central

    Calzada, Audrey P.; Lopez, Ivan A.; Ishiyama, Gail; Ishiyama, Akira

    2012-01-01

    Objectives 1. Evaluate the otolithic membrane in patients with endolymphatic hydrops (EH) and vestibular drop attacks (VDA) undergoing ablative labyrinthectomy. 2. Correlate intraoperative findings to archival temporal bone specimens of patients with EH. Study Design Retrospective case review Setting Tertiary referral center Specimen source 1. Patients undergoing labyrinthectomy for incapacitating Meniere’s disease (MD), delayed EH, VDA, or acoustic neuroma (AN) between 2004 and 2011. 2. Archival temporal bone specimens of patients with MD. Interventions Ablative labyrinthectomy Main outcome measures Examination of the utricular otolithic membrane. Results The otolithic membrane of the utricle was evaluated intraoperatively in 28 patients undergoing labyrinthectomy. 7 (25%) had a history of VDA, 6 (21%) had delayed EH, 9 (32%) had MD, and 6 (21%) had AN. All patients with VDA showed evidence of a disrupted utricular otolithic membrane, whereas only 50% and 56% of patients with delayed EH and MD respectively, demonstrated otolithic membrane disruption (p = 0.051). None of the patients with AN showed otolithic membrane disruption (p = 0.004). The mean thickness of the otolithic membrane in 5 archival temporal bone MD specimens was 11.45 micrometers versus 38 micrometers in normal specimens (p=0.001). Conclusions The otolithic membrane is consistently damaged in patients with VDA. In addition, there is a significantly higher incidence of otolithic membrane injury in patients with MD and delayed EH compared to patients without hydrops, suggesting that the underlying pathophysiology in VDA results from injury to the otolithic membrane of the saccule and utricle, resulting in free-floating otoliths and atrophy. PMID:23064391

  12. Corneal plaque containing levofloxacin in a dog.

    PubMed

    Park, Young-Woo; Kang, Byung-Jae; Lim, Jae Hyun; Ahn, Jung-Mo; Lim, Hyun Sook

    2015-11-01

    A 13-year-old castrated male Yorkshire terrier developed a corneal ulcer 2 weeks after intracapsular lens extraction (ICLE) in the right eye. The corneal ulcer was treated with levofloxacin eye drops. A plaque with a white luster developed in the central cornea 2 weeks after treatment with levofloxacin eye drops. The corneal plaque was surgically removed under inhalant anesthesia. The corneal plaque displayed antimicrobial activity against Escherichia coli. Furthermore, levofloxacin content in the plaque was confirmed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry (MS). The corneal ulcer completely resolved 2 weeks after the surgical removal of the corneal lesion and replacement of levofloxacin eye drops with tobramycin eye drops. Although the topical use of levofloxacin is unlikely to lead to corneal chemical deposits due to the high water solubility of the drug compared to other topical fluoroquinolones, this patient developed corneal plaque of the antibiotic drop.

  13. Corneal biomechanics: a review.

    PubMed

    Piñero, David P; Alcón, Natividad

    2015-03-01

    Biomechanics is often defined as 'mechanics applied to biology'. Due to the variety and complexity of the behaviour of biological structures and materials, biomechanics is better defined as the development, extension and application of mechanics for a better understanding of physiology and physiopathology and consequently for a better diagnosis and treatment of disease and injury. Different methods for the characterisation of corneal biomechanics are reviewed in detail, including those that are currently commercially available (Ocular Response Analyzer and CorVis ST). The clinical applicability of the parameters provided by these devices are discussed, especially in the fields of glaucoma, detection of ectatic disorders and orthokeratology. Likewise, other methods are also reviewed, such as Brillouin microscopy or dynamic optical coherence tomography and others with potential application to clinical practice but not validated for in vivo measurements, such as ultrasonic elastography. Advantages and disadvantages of all these techniques are described. Finally, the concept of biomechanical modelling is revised as well as the requirements for developing biomechanical models, with special emphasis on finite element modelling.

  14. Corneal cryopreservation with dextran.

    PubMed

    Halberstadt, M; Athmann, S; Hagenah, M

    2001-08-01

    Different methods of corneal cryopreservation have been introduced, those employing intracellular cryoprotectants such as Me2SO or glycerol being the most widely favored. We investigated the influence of several freeze-thaw trauma variables on the survival of porcine endothelial monolayers when employing the extracellular cryoprotective agent dextran. We first examined the effects of various dextran concentrations and then, having ascertained the optimal concentration, further investigated the influence of fetal calf serum (FCS) concentration in the cryopreservation medium, the cooling rate, the thawing temperature, and the length of the preincubation in the freezing medium prior to cryopreservation. The numerical densities of endothelial cells were determined at dissection in hypoosmotic balanced salt solution and after organ culture by staining with alizarin red S and trypan blue. Morphological evaluation was not performed directly after thawing but after a subsequent organ culture at 37 degrees C to detect latent cell damage after freeze-thaw trauma. Our data revealed that corneas cryopreserved in minimal essential medium containing 10% dextran but lacking FCS, preincubated for 3 h, frozen at a cooling rate of 1 degrees C/min, and thawed at 37 degrees C incurred the lowest cell losses (22.4%, SD +/- 3.8). We conclude that dextran is an effective cryoprotectant for freezing of porcine corneas. However, variations between species in the results of cryopreservation require further investigation of an in vivo animal model and studies with human corneas before its clinical use can be recommended.

  15. Corneal temperature in schizophrenia patients.

    PubMed

    Shiloh, Roni; Munitz, Hanan; Portuguese, Shirley; Gross-Isseroff, Ruth; Sigler, Mayanit; Bodinger, Liron; Katz, Nachum; Stryjer, Rafael; Hermesh, Haggai; Weizman, Abraham

    2005-12-01

    Most data imply that dopaminergic transmission is essential for proper hypothalamic-mediated core temperature regulation. Altered central dopaminergic transmission is suggested to be involved in the pathophysiology of schizophrenia. Thus, hypothetically, schizophrenia patients might be at increased risk of developing thermoregulatory dysregulation manifested by alterations in core temperature, as well as in peripheral tissue, the temperature of which has been shown to correlate with core temperature (e.g. cornea). Previous small pilot studies of ours showed that schizophrenia patients may exhibit corneal temperature abnormalities. Hence, we assessed corneal temperature in a controlled sample of drug-free ( n =11) and medicated ( n =28) schizophrenia patients compared to healthy comparison subjects ( n =9), using a FLIR thermal imaging camera. Drug-free schizophrenia patients exhibited significantly higher corneal temperature compared to healthy subjects, typical antipsychotic drug (APD)-treated patients ( n =16) and atypical APD-treated patients ( n =12) (37.08+/-1.46 degrees C vs. 33.37+/-2.51 degrees C, 31.08+/-1.43 degrees C and 31.67+/-0.44 degrees C respectively, p <0.0001; p <0.001 vs. each group separately). The healthy comparison subjects and the atypical APD-treated patients exhibited comparable corneal temperatures and these two groups exhibited higher corneal temperatures compared to the typical APD-treated patients ( p <0.01 and p =0.051 respectively). In conclusion, this study indicates that drug-free schizophrenia patients exhibit substantially higher corneal temperature compared to healthy comparison subjects or medicated patients, and that APDs may decrease corneal temperature either to normal (atypical APD) or to subnormal (typical APD) values. The relevance of these phenomena to the pathophysiology of schizophrenia, the biological mechanism underlying drug-induced corneal temperature alterations, the possible role of temperature-lowering drugs

  16. Topical Drug Formulations for Prolonged Corneal Anesthesia

    PubMed Central

    Wang, Liqiang; Shankarappa, Sahadev A.; Tong, Rong; Ciolino, Joseph B.; Tsui, Jonathan H.; Chiang, Homer H.; Kohane, Daniel S.

    2013-01-01

    Purpose Ocular local anesthetics (OLA’s) currently used in routine clinical practice for corneal anesthesia are short acting and their ability to delay corneal healing makes them unsuitable for long-term use. In this study, we examined the effect on the duration of corneal anesthesia of the site-1 sodium channel blocker tetrodotoxin (TTX), applied with either proparacaine or the chemical permeation enhancer OTAB. The effect of test solutions on corneal healing was also studied. Methods Solutions of TTX, proparacaine, and OTAB, singly or in combination were applied topically to the rat cornea. The blink response, an indirect measure of corneal sensitivity, was recorded using a Cochet-Bonnet esthesiometer, and the duration of corneal anesthesia calculated. The effect of test compounds on the rate of corneal epithelialization was studied in vivo following corneal debridement. Results Combination of TTX and proparacaine resulted in corneal anesthesia that was 8–10 times longer in duration than that from either drug administered alone, while OTAB did not prolong anesthesia. The rate of corneal healing was moderately delayed following co-administration of TTX and proparacaine. Conclusion Co-administration of TTX and proparacaine significantly prolonged corneal anesthesia but in view of delayed corneal re-epithelialization, caution is suggested in use of the combination. PMID:23615270

  17. Obtaining corneal tissue for keratoplasty.

    PubMed

    Navarro Martínez-Cantullera, A; Calatayud Pinuaga, M

    2016-10-01

    Cornea transplant is the most common tissue transplant in the world. In Spain, tissue donation activities depend upon transplant coordinator activities and the well-known Spanish model for organ and tissue donation. Tissue donor detection system and tissue donor evaluation is performed mainly by transplant coordinators using the Spanish model on donation. The evaluation of a potential tissue donor from detection until recovery is based on an exhaustive review of the medical and social history, physical examination, family interview to determine will of the deceased, and a laboratory screening test. Corneal acceptance criteria for transplantation have a wider spectrum than other tissues, as donors with active malignancies and infections are accepted for kearatoplasty in most tissue banks. Corneal evaluation during the whole process is performed to ensure the safety of the donor and the recipient, as well as an effective transplant. Last step before processing, corneal recovery, must be performed under standard operating procedures and in a correct environment.

  18. Gene Therapy in Corneal Transplantation

    PubMed Central

    Qazi, Yureeda; Hamrah, Pedram

    2014-01-01

    Corneal transplantation is the most commonly performed organ transplantation. Immune privilege of the cornea is widely recognized, partly because of the relatively favorable outcome of corneal grafts. The first-time recipient of corneal allografts in an avascular, low-risk setting can expect a 90% success rate without systemic immunosuppressive agents and histocompatibility matching. However, immunologic rejection remains the major cause of graft failure, particularly in patients with a high risk for rejection. Corticosteroids remain the first-line therapy for the prevention and treatment of immune rejection. However, current pharmacological measures are limited in their side-effect profiles, repeated application, lack of targeted response, and short duration of action. Experimental ocular gene therapy may thus present new horizons in immunomodulation. From efficient viral vectors to sustainable alternative splicing, we discuss the progress of gene therapy in promoting graft survival and postulate further avenues for gene-mediated prevention of allogeneic graft rejection. PMID:24138037

  19. Correlations between corneal and total wavefront aberrations

    NASA Astrophysics Data System (ADS)

    Mrochen, Michael; Jankov, Mirko; Bueeler, Michael; Seiler, Theo

    2002-06-01

    Purpose: Corneal topography data expressed as corneal aberrations are frequently used to report corneal laser surgery results. However, the optical image quality at the retina depends on all optical elements of the eye such as the human lens. Thus, the aim of this study was to investigate the correlations between the corneal and total wavefront aberrations and to discuss the importance of corneal aberrations for representing corneal laser surgery results. Methods: Thirty three eyes of 22 myopic subjects were measured with a corneal topography system and a Tschernig-type wavefront analyzer after the pupils were dilated to at least 6 mm in diameter. All measurements were centered with respect to the line of sight. Corneal and total wavefront aberrations were calculated up to the 6th Zernike order in the same reference plane. Results: Statistically significant correlations (p < 0.05) between the corneal and total wavefront aberrations were found for the astigmatism (C3,C5) and all 3rd Zernike order coefficients such as coma (C7,C8). No statistically significant correlations were found for all 4th to 6th order Zernike coefficients except for the 5th order horizontal coma C18 (p equals 0.003). On average, all Zernike coefficients for the corneal aberrations were found to be larger compared to Zernike coefficients for the total wavefront aberrations. Conclusions: Corneal aberrations are only of limited use for representing the optical quality of the human eye after corneal laser surgery. This is due to the lack of correlation between corneal and total wavefront aberrations in most of the higher order aberrations. Besides this, the data present in this study yield towards an aberration balancing between corneal aberrations and the optical elements within the eye that reduces the aberration from the cornea by a certain degree. Consequently, ideal customized ablations have to take both, corneal and total wavefront aberrations, into consideration.

  20. Progress in corneal wound healing

    PubMed Central

    Ljubimov, Alexander V.; Saghizadeh, Mehrnoosh

    2015-01-01

    Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal epithelium, and

  1. Precision Measurement Of Corneal Topography

    NASA Astrophysics Data System (ADS)

    Yoder, Paul R.; Macri, Timothy F.; Telfair, William B.; Bennett, Peter S.; Martin, Clifford A.; Warner, John W.

    1989-05-01

    We describe a new electro-optical device being developed to provide precise measurements of the three-dimensional topography of the human cornea. This device, called a digital keratoscope, is intended primarily for use in preparing for and determining the effect of corneal surgery procedures such as laser refractive keratectomy, radial keratotomy or corneal transplant on the refractive power of the cornea. It also may serve as an aid in prescribing contact lenses. The basic design features of the hardware and of the associated computer software are discussed, the means for alignment and calibration are described and typical results are given.

  2. Nonimmune fetal hydrops and placentomegaly: Diagnosis of familial Wiedemann-Beckwith syndrome with trisomy 11p15 using FISH

    SciTech Connect

    Drut, R.M.; Drut, R.

    1996-03-15

    We have studied a family in which four members of the same generation were affected with Wiedemann-Beckwith syndrome (WBS). Trisomy 11p15 was demonstrated using molecular probes in interphase nuclei of formalin-fixed paraffin-embedded placenta from a stillborn fetus and in peripheral blood lymphocytes from two liveborn female relatives. Clinical examination showed nonimmune hydrops and placentomegaly in two siblings and multiple phenotypic abnormalities consistent with WBS in the two other relatives. Paternal karyotype of the stillborn infants demonstrated a reciprocal translocation (46,XY,t(10;11) (q26;p15)) explaining the origin of the extra 11p15 material. This study illustrates the advantages of FISH for interphase analysis of chromosome aberrations otherwise not detected even by conventional cytogenetic analysis and documents that nonimmune hydrops associated with placentomegaly may be presenting features in familial WBS. 24 refs., 6 figs.

  3. Prenatal management and perinatal outcome in giant placental chorioangioma complicated with hydrops fetalis, fetal anemia and maternal mirror syndrome

    PubMed Central

    2012-01-01

    Background Giant placental chorioangiomas have been associated with a number of severe fetal complications and high perinatal mortality. Case presentation We report a case of giant chorioangioma with fetal hydrops, additionally complicated by severe anemia, mild cardiomegaly with hyperdinamic heart circulation and maternal mirror syndrome. Intrauterine blood transfusion and amniodrainage was performed at 29 weeks. Worsening of the fetal and maternal condition prompted us to proceed with delivery at 29 + 5 weeks. The newborn died 3 hours later due to pulmonary hypoplasia and hemodynamic failure. Maternal course was favourable, mirror syndrome resolved in the second day and the patient was discharged four days following delivery. Conclusions In the case described here, fetal condition got worse despite of the anemia correction and amniodrainage. Our outcome raises the issue whether additional intrauterine clinical intervention, as intersticial laser, should have been performed to stop further deterioration of the fetal condition when progressive severe hydrops develops. PMID:22840187

  4. Corneal Regeneration After Photorefractive Keratectomy: A Review☆

    PubMed Central

    Tomás-Juan, Javier; Murueta-Goyena Larrañaga, Ane; Hanneken, Ludger

    2014-01-01

    Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain. PMID:25444646

  5. History of corneal transplantation in Australia.

    PubMed

    Coster, Douglas J

    2015-04-01

    Corneal transplantation is a triumph of modern ophthalmology. The possibility of corneal transplantation was first raised in 1797 but a century passed before Zirm achieved the first successful penetrating graft in 1905. Gibson reported the first corneal graft in Australia from Brisbane in 1940 and English established the first eye bank there a few years later. Corneal transplantation evolved steadily over the twentieth century. In the second half of the century, developments in microsurgery, including surgical materials such as monofilament nylon and strong topical steroid drops, accounted for improvements in outcomes. In 2013, approximately 1500 corneal transplants were done in Australia. Eye banking has evolved to cope with the rising demands for donor corneas. Australian corneal surgeons collaborated to establish and support the Australian Corneal Graft Registry in 1985. It follows the outcomes of their surgery and has become an important international resource for surgeons seeking further improvement with the procedure.

  6. Corneal Regeneration After Photorefractive Keratectomy: A Review.

    PubMed

    Tomás-Juan, Javier; Murueta-Goyena Larrañaga, Ane; Hanneken, Ludger

    2015-01-01

    Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain.

  7. Effects of topical and systemic administration of Eugenia caryophyllata buds essential oil on corneal anesthesia and analgesia

    PubMed Central

    Khalilzadeh, Emad; Hazrati, Reza; Saiah, Gholamreza Vafaei

    2016-01-01

    Clinical studies suggest that essential oil of Eugenia caryophyllata (Clove) buds (EOEC) is efficacious in the treatment of dental pain. In the present study, we investigated the analgesic and local anesthetic effects of EOEC and its possible mechanisms of action in acute corneal pain in rats. EOEC was extracted by hydro-distillation in a Clevenger type apparatus from clove buds. The acute corneal pain was induced by applying a drop (40 µl) of 5 M NaCl solution on the corneal surface, and the numbers of eye wipes were counted during the first 30 s. The mechanical sensation of the cornea was evaluated by calibrated Von Frey filaments. Systemic administration of EOEC (100 and 200 mg/kg, SC) and morphine (2.5 and 5 mg/kg, IP) produced a significant antinociceptive effect in acute corneal pain. Pretreatment with naloxone or atropine prevented the EOEC-induced analgesia. However, L-arginine and methylene blue did not change the suppressive effect of EOEC on corneal pain response. Topical application of EOEC, eugenol and lidocaine significantly decreased corneal sensitivity. Combination treatments of eugenol (25 µg) with lidocaine (0.5%) and EOEC (50 µg) with lidocaine (0.5%) also significantly suppressed corneal sensitivity. Systemic administration of EOEC produced analgesia in the acute corneal pain through mechanisms that involved both opioidergic and cholinergic systems. In addition, topical instillation of EOEC, eugenol, and lidocaine produced local anesthesia in the rat cornea. Sub-anesthetic doses of EOEC or eugenol produced a significant local anesthetic effect when concurrently used with the sub-anesthetic dose of lidocaine. PMID:27651809

  8. Corneal Stroma Microfibrils

    PubMed Central

    Hanlon, Samuel D.; Behzad, Ali R.; Sakai, Lynn Y.; Burns, Alan R.

    2015-01-01

    Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (∼10nm diameter). Immunogold evidence clearly

  9. Biomechanics of Corneal Ring Implants

    PubMed Central

    2015-01-01

    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. Results: For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. Conclusions: The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus. PMID:26312619

  10. Immunological aspects of corneal transplant.

    PubMed

    Kumar, Vijay; Kumar, Asha

    2014-01-01

    Corneal transplant is the most common solid tissue transplant in humans. Advances in microsurgical techniques, eye banking and the use of corticosteroids have improved the success of corneal transplants. Over 65,000 corneal transplants are being performed worldwide annually. Most of these transplants are performed in developed countries. Cornea is considered an immune privileged site. Despite this, immune mediated graft rejection is the most single cause of cornea graft failure and is one of the major postoperative complications. Incidences from as low as 2% to as high as 50% have been reported depending upon the degree of vascularization. Rejection involves donor tissue recognition and various factors may influence this rejection. Major factors include the antigenic load of the donor tissue; other factors include death to enucleation time, methods and temperature of preserving the tissue. Host factors that may impact the graft include ocular surface diseases such as dry eye, chemical burns and autoimmune diseases such as mucous membrane pemphigoid. Following infection, surgery or trauma, cells of the innate immune system invade the cornea as a result of up-regulation of cytokines, cellular adhesion molecules and growth and angiogenic factors. These factors results in neoangiogenesis and lymphoangiogenesis, leading to immune activation and graft rejection. The various immunological mechanisms that may play a role in the corneal transplant are discussed.

  11. Corneal Protection for Burn Patients

    DTIC Science & Technology

    2013-10-01

    corneal collagen as a treatment for keratoconus (1) indicating that it is a safe photosensitizer. The maximum percent inhibition using RF and blue light...Seiler (2003) Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus . Am J Ophthalmol, 135, 620-7. 2. Fujisato, T

  12. Corneal Protection for Burn Patients

    DTIC Science & Technology

    2010-07-01

    blue light. RF-5P with UVA irradiation has recently been used to crosslink corneal collagen as a treatment for keratoconus (2). Thus, RF-5P appears...induced collagen crosslinking for the treatment of keratoconus . American journal of ophthalmology. 2003 May;135(5):620-7. 3. McCall AS, Kraft S

  13. Corneal injury by wild taro.

    PubMed

    Tang, Emily W H; Law, Ricky W K; Lai, Jimmy S M

    2006-12-01

    We report a case of crystalline keratopathy caused by Alocasia macrorrhiza. The diagnosis was made based on the observation of needle-like crystals in the corneal stroma following injury to that eye. The condition resolved in 3 months with the disappearance of the crystals confirmed by follow-up confocal microscopy.

  14. Corneal microprojections in coleoid cephalopods.

    PubMed

    Talbot, Christopher; Jordan, Thomas M; Roberts, Nicholas W; Collin, Shaun P; Marshall, N Justin; Temple, Shelby E

    2012-12-01

    The cornea is the first optical element in the path of light entering the eye, playing a role in image formation and protection. Corneas of vertebrate simple camera-type eyes possess microprojections on the outer surface in the form of microridges, microvilli, and microplicae. Corneas of invertebrates, which have simple or compound eyes, or both, may be featureless or may possess microprojections in the form of nipples. It was previously unknown whether cephalopods (invertebrates with camera-type eyes like vertebrates) possess corneal microprojections and, if so, of what form. Using scanning electron microscopy, we examined corneas of a range of cephalopods and discovered nipple-like microprojections in all species. In some species, nipples were like those described on arthropod compound eyes, with a regular hexagonal arrangement and sizes ranging from 75 to 103 nm in diameter. In others, nipples were nodule shaped and irregularly distributed. Although terrestrial invertebrate nipples create an antireflective surface that may play a role in camouflage, no such optical function can be assigned to cephalopod nipples due to refractive index similarities of corneas and water. Their function may be to increase surface-area-to-volume ratio of corneal epithelial cells to increase nutrient, gas, and metabolite exchange, and/or stabilize the corneal mucous layer, as proposed for corneal microprojections of vertebrates.

  15. Terahertz sensing of corneal hydration.

    PubMed

    Singh, Rahul S; Tewari, Priyamvada; Bourges, Jean Louis; Hubschman, Jean Pierre; Bennett, David B; Taylor, Zachary D; Lee, H; Brown, Elliott R; Grundfest, Warren S; Culjat, Martin O

    2010-01-01

    An indicator of ocular health is the hydrodyanmics of the cornea. Many corneal disorders deteriorate sight as they upset the normal hydrodynamics of the cornea. The mechanisms include the loss of endothelial pump function of corneal dystophies, swelling and immune response of corneal graft rejection, and inflammation and edema, which accompany trauma, burn, and irritation events. Due to high sensitivity to changes of water content in materials, a reflective terahertz (300 GHz and 3 THz) imaging system could be an ideal tool to measure the hydration level of the cornea. This paper presents the application of THz technology to visualize the hydration content across ex vivo porcine corneas. The corneas, with a thickness variation from 470 - 940 µm, were successfully imaged using a reflective pulsed THz imaging system, with a maximum SNR of 50 dB. To our knowledge, no prior studies have reported on the use of THz in measuring hydration in corneal tissues or other ocular tissues. These preliminary findings indicate that THz can be used to accurately sense hydration levels in the cornea using a pulsed, reflective THz imaging system.

  16. IL-17 and VEGF are necessary for efficient corneal nerve regeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contribution of acute inflammation to sensory nerve regeneration was investigated in the murine cornea using a model of corneal abrasion that removes the stratified epithelium and subbasal nerve plexus. Abrasion induced accumulation of IL-17(+) CCR6(+) yo T cells, neutrophils, and platelets in t...

  17. KLF1-null neonates display hydrops fetalis and a deranged erythroid transcriptome

    PubMed Central

    Magor, Graham W.; Tallack, Michael R.; Gillinder, Kevin R.; Bell, Charles C.; McCallum, Naomi; Williams, Bronwyn

    2015-01-01

    We describe a case of severe neonatal anemia with kernicterus caused by compound heterozygosity for null mutations in KLF1, each inherited from asymptomatic parents. One of the mutations is novel. This is the first described case of a KLF1-null human. The phenotype of severe nonspherocytic hemolytic anemia, jaundice, hepatosplenomegaly, and marked erythroblastosis is more severe than that present in congenital dyserythropoietic anemia type IV as a result of dominant mutations in the second zinc-finger of KLF1. There was a very high level of HbF expression into childhood (>70%), consistent with a key role for KLF1 in human hemoglobin switching. We performed RNA-seq on circulating erythroblasts and found that human KLF1 acts like mouse Klf1 to coordinate expression of many genes required to build a red cell including those encoding globins, cytoskeletal components, AHSP, heme synthesis enzymes, cell-cycle regulators, and blood group antigens. We identify novel KLF1 target genes including KIF23 and KIF11 which are required for proper cytokinesis. We also identify new roles for KLF1 in autophagy, global transcriptional control, and RNA splicing. We suggest loss of KLF1 should be considered in otherwise unexplained cases of severe neonatal NSHA or hydrops fetalis. PMID:25724378

  18. Imaging, Reconstruction, And Display Of Corneal Topography

    NASA Astrophysics Data System (ADS)

    Klyce, Stephen D.; Wilson, Steven E.

    1989-12-01

    The cornea is the major refractive element in the eye; even minor surface distortions can produce a significant reduction in visual acuity. Standard clinical methods used to evaluate corneal shape include keratometry, which assumes the cornea is ellipsoidal in shape, and photokeratoscopy, which images a series of concentric light rings on the corneal surface. These methods fail to document many of the corneal distortions that can degrade visual acuity. Algorithms have been developed to reconstruct the three dimensional shape of the cornea from keratoscope images, and to present these data in the clinically useful display of color-coded contour maps of corneal surface power. This approach has been implemented on a new generation video keratoscope system (Computed Anatomy, Inc.) with rapid automatic digitization of the image rings by a rule-based approach. The system has found clinical use in the early diagnosis of corneal shape anomalies such as keratoconus and contact lens-induced corneal warpage, in the evaluation of cataract and corneal transplant procedures, and in the assessment of corneal refractive surgical procedures. Currently, ray tracing techniques are being used to correlate corneal surface topography with potential visual acuity in an effort to more fully understand the tolerances of corneal shape consistent with good vision and to help determine the site of dysfunction in the visually impaired.

  19. Corneal graft rejection occurs despite Fas ligand expression and apoptosis of infiltrating cells

    PubMed Central

    Williams, K A; Standfield, S D; Smith, J R; Coster, D J

    2005-01-01

    Background/aims: Constitutive expression of Fas ligand (CD95L) protects the eye against cell mediated immune responses by inducing apoptosis in infiltrating Fas bearing T cells. This study was designed to examine Fas ligand expression on acutely rejecting rat corneal grafts and to investigate the kinetics of induction of apoptosis in infiltrating leucocytes. Methods: Orthotopic penetrating corneal transplantation was performed between genetically disparate inbred rats. Fas ligand expression and the phenotype of infiltrating leucocytes were examined by immunohistochemistry. Apoptotic nuclei were visualised in sections of normal rat cornea, rejecting allografts, and time matched isografts by terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labelling (TUNEL) and quantified by video image analysis. Staining with Hoechst dye 33258 was used to confirm the presence of apoptotic nuclei. Results: Fas ligand was expressed on corneal endothelial and epithelial cells during acute corneal graft rejection. At all time points examined, including as early as the fifth postoperative day, the cells infiltrating both corneal isografts and allografts were TUNEL positive. By the 15th postoperative day, over 90% of all nuclei, many of which were T cells, were apoptotic. Conclusion: Expression of Fas ligand is not downregulated on the cornea during allograft rejection and infiltrating leucocytes in both isografts and allografts die rapidly in situ. Despite the death of the cells believed to be responsible for rejection, isografts survive indefinitely whereas allografts are irreparably damaged. PMID:15834099

  20. Localization and expression of zonula occludins-1 in the rabbit corneal epithelium following exposure to benzalkonium chloride.

    PubMed

    Chen, Wensheng; Hu, Jiaoyue; Zhang, Zhenhao; Chen, Lelei; Xie, Hui; Dong, Nuo; Chen, Yongxiong; Liu, Zuguo

    2012-01-01

    Preservatives are a major component of the ophthalmic preparations in multi-dose bottles. The purpose of this study was to investigate the acute effect of benzalkonium chloride (BAC), a common preservative used in ophthalmic preparations, on the localization and expression of zonula occludens (ZO)-1 in the rabbit corneal epithelium in vivo. BAC at 0.005%, 0.01%, or 0.02% was topically applied to one eye each of albino rabbits at 5 min intervals for a total of 3 times. The contralateral untreated eyes served as controls. The following clinical indications were evaluated: Schirmer test, tear break-up time (BUT), fluorescein and rose Bengal staining. The structure of central cornea was examined by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance and permeability to carboxy fluorescein. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of ZO-1, 2, occludin, claudin-1, Ki67 and cell apoptosis in the epithelium. The expression of ZO-1 in the corneal epithelium was also examined by western blot and reverse transcription-polymerase chain reaction analyses. Exposure to BAC resulted in higher rose Bengal staining scores while no significant changes in BUT, Schirmer and corneal florescein scores. It also induced corneal epithelial cell damage, dispersion of ZO-1 and ZO-2 from their normal locus at the superficial layer and disruption of epithelial barrier function. However, the amounts of ZO-1 mRNA and protein in the corneal epithelium were not affected by BAC treatment. Exposure to BAC can quickly impair the corneal epithelium without tear deficiency. BAC disrupts the tight junctions of corneal epithelium between superficial cells in the rabbit corneal epithelium in vivo.

  1. Localization and Expression of Zonula Occludins-1 in the Rabbit Corneal Epithelium following Exposure to Benzalkonium Chloride

    PubMed Central

    Zhang, Zhenhao; Chen, Lelei; Xie, Hui; Dong, Nuo; Chen, Yongxiong; Liu, Zuguo

    2012-01-01

    Preservatives are a major component of the ophthalmic preparations in multi-dose bottles. The purpose of this study was to investigate the acute effect of benzalkonium chloride (BAC), a common preservative used in ophthalmic preparations, on the localization and expression of zonula occludens (ZO)-1 in the rabbit corneal epithelium in vivo. BAC at 0.005%, 0.01%, or 0.02% was topically applied to one eye each of albino rabbits at 5 min intervals for a total of 3 times. The contralateral untreated eyes served as controls. The following clinical indications were evaluated: Schirmer test, tear break-up time (BUT), fluorescein and rose Bengal staining. The structure of central cornea was examined by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance and permeability to carboxy fluorescein. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of ZO-1, 2, occludin, claudin-1, Ki67 and cell apoptosis in the epithelium. The expression of ZO-1 in the corneal epithelium was also examined by western blot and reverse transcription-polymerase chain reaction analyses. Exposure to BAC resulted in higher rose Bengal staining scores while no significant changes in BUT, Schirmer and corneal florescein scores. It also induced corneal epithelial cell damage, dispersion of ZO-1 and ZO-2 from their normal locus at the superficial layer and disruption of epithelial barrier function. However, the amounts of ZO-1 mRNA and protein in the corneal epithelium were not affected by BAC treatment. Exposure to BAC can quickly impair the corneal epithelium without tear deficiency. BAC disrupts the tight junctions of corneal epithelium between superficial cells in the rabbit corneal epithelium in vivo. PMID:22815857

  2. [Research and development for treating devastating corneal diseases].

    PubMed

    Kinoshita, Shigeru

    2010-03-01

    In order to develop new therapeutic modalities for corneal diseases, it is essential to combine cutting-edge translational research based upon liberal original ideas obtained from clinical experience with state-of-the-art basic science and technology. Here, I describe seven important research projects on which our group has been working. 1. Elucidation of the pathogenesis in gelatinous drop-like corneal dystrophy(GDLD). Due to loss of function of the tumor-associated calcium signal transducer 2 (TACSTD2), a responsible gene for this dystrophy, tight-junction-related proteins cease to function, resulting in severe corneal epithelial barrier impairment. As a result, various proteins contained in tear fluid continuously penetrate into the corneal stroma, promoting the development of massive amyloid deposits. 2. The development of cultivated mucosal epithelial transplantation: A landmark surgery, involving the transplantation of cultivated mucosal epithelial cells from in vitro to in vivo, now recognized as the next generation of ocular surface reconstruction. We began performing cultivated allocorneal epithelial transplantations in 1999, and cultivated auto-corneal and auto-oral mucosal epithelial transplantations in 2002. These proved to be very effective in the reconstruction of both the corneal surface and the conjunctival fornix. 3. Elucidation of the pathogenesis of Stevens-Johnson syndrome: Studies have shown that there is a close relationship between corneal epithelial stem cell loss and the associated degree of visual impairment. We discovered that a steroid pulse therapy at the acute phase aimed at minimizing stem cell loss is very effective in restoring visual acuity. This implies that inhibition of the cytokine storm is essential for the treatment of acute-phase Stevens-Johnson syndrome. The innate immunity abnormality seems to be heavily involved at the onset of this devastating disease. 4. Elucidation of the involvement of EP3 and toll like receptor 3

  3. [Regeneration and fibrosis of corneal tissues].

    PubMed

    Simirskiĭ, V N

    2014-01-01

    In this review, the features of the regeneration of corneal tissue and its disorders leading to the development of fibrosis are considered. The data on the presence of stem (clonogenic) cell pool in the corneal tissues (epithelium, endothelium, stroma) are given; these cells can serve as a source for regeneration of the tissues at injury or various diseases. The main steps of regeneration of corneal tissues and their disorders that lead to outstripping proliferation of myofibroblasts and secretion of extracellular matrix in the wound area and eventually cause the formation of connective tissue scar and corneal opacity are considered. Particular attention is given to the successes of translational medicine in the treatment of corneal tissue fibrosis. The methods of cell therapy aimed at the restoration of stem cell pool of corneal tissues are the most promising. Gene therapy provides more opportunities; one of its main objectives is the suppression of the myofibroblast proliferation responsible for the development of fibrosis.

  4. Bilateral and unilateral mesodermal corneal metaplasia.

    PubMed Central

    Klauss, V; Riedel, K

    1983-01-01

    We report on 2 infants, one with a bilateral and the other with a unilateral corneal metaplasia. The first case with bilateral corneal metaplasia showed shortening of both upper and lower lids with formation of symblephara. By ultrasonography the right eye presented with microphthalmos, aphakia, and persistent hyaloid, whereas the inner parts of the left eye appeared to be normal. The question remains to be answered whether this is an abortive cryptophthalmos leading to bilateral corneal metaplasia or a primary corneal metaplasia inhibiting the lid growth. No suggestions concerning the aetiology are made. The second case presented with a unilateral corneal metaplasia, normal eye lids, aphakia, and microphthalmos. This aberration was probably caused by an amniotic band, as it is associated with malformation of the nose on the same side. In case 2 the dermoid was excised and a lamellar corneal graft performed. The histology is reported. Images PMID:6838805

  5. Effects of Topically Applied Vitamin D during Corneal Wound Healing.

    PubMed

    Reins, Rose Y; Hanlon, Samuel D; Magadi, Sri; McDermott, Alison M

    2016-01-01

    Vitamin D is an important regulator of immune function and largely acts to dampen chronic inflammatory events in a variety of tissues. There is also accumulating evidence that vitamin D acts to enhance initial inflammation, beneficial during both infection and wound healing, and then promotes resolution and prevention of chronic, damaging inflammation. The current study examines the effect of topical vitamin D in a mouse of model of corneal epithelial wound healing, where acute inflammation is necessary for efficient wound closure. At 12 and 18 hours post-wounding, vitamin D treatment significantly delayed wound closure by ~17% and increased infiltration of neutrophils into the central cornea. Basal epithelial cell division, corneal nerve density, and levels of VEGF, TGFβ, IL-1β, and TNFα were unchanged. However, vitamin D increased the production of the anti-microbial peptide CRAMP 12 hours after wounding. These data suggest a possible role for vitamin D in modulating corneal wound healing and have important implications for therapeutic use of vitamin D at the ocular surface.

  6. Effects of Topically Applied Vitamin D during Corneal Wound Healing

    PubMed Central

    Reins, Rose Y.; Hanlon, Samuel D.; Magadi, Sri; McDermott, Alison M.

    2016-01-01

    Vitamin D is an important regulator of immune function and largely acts to dampen chronic inflammatory events in a variety of tissues. There is also accumulating evidence that vitamin D acts to enhance initial inflammation, beneficial during both infection and wound healing, and then promotes resolution and prevention of chronic, damaging inflammation. The current study examines the effect of topical vitamin D in a mouse of model of corneal epithelial wound healing, where acute inflammation is necessary for efficient wound closure. At 12 and 18 hours post-wounding, vitamin D treatment significantly delayed wound closure by ~17% and increased infiltration of neutrophils into the central cornea. Basal epithelial cell division, corneal nerve density, and levels of VEGF, TGFβ, IL-1β, and TNFα were unchanged. However, vitamin D increased the production of the anti-microbial peptide CRAMP 12 hours after wounding. These data suggest a possible role for vitamin D in modulating corneal wound healing and have important implications for therapeutic use of vitamin D at the ocular surface. PMID:27035345

  7. Murine Corneal Inflammation and Nerve Damage After Infection With HSV-1 Are Promoted by HVEM and Ameliorated by Immune-Modifying Nanoparticle Therapy

    PubMed Central

    Edwards, Rebecca G.; Kopp, Sarah J.; Ifergan, Igal; Shui, Jr-Wen; Kronenberg, Mitchell; Miller, Stephen D.; Longnecker, Richard

    2017-01-01

    Purpose To determine cellular and temporal expression patterns of herpes virus entry mediator (HVEM, Tnfrsf14) in the murine cornea during the course of herpes simplex virus 1 (HSV-1) infection, the impact of this expression on pathogenesis, and whether alterations in HVEM or downstream HVEM-mediated effects ameliorate corneal disease. Methods Corneal HVEM levels were assessed in C57BL/6 mice after infection with HSV-1(17). Leukocytic infiltrates and corneal sensitivity loss were measured in the presence, global absence (HVEM knockout [KO] mice; Tnfrsf14−/−), or partial absence of HVEM (HVEM conditional KO). Effects of immune-modifying nanoparticles (IMPs) on viral replication, corneal sensitivity, and corneal infiltrates were measured. Results Corneal HVEM+ populations, particularly monocytes/macrophages during acute infection (3 days post infection [dpi]) and polymorphonuclear neutrophils (PMN) during the chronic inflammatory phase (14 dpi), increased after HSV-1 infection. Herpes virus entry mediator increased leukocytes in the cornea and corneal sensitivity loss. Ablation of HVEM from CD45+ cells, or intravenous IMP therapy, reduced infiltrates in the chronic phase and maintained corneal sensitivity. Conclusions Herpes virus entry mediator was expressed on two key populations: corneal monocytes/macrophages and PMNs. Herpes virus entry mediator promoted the recruitment of myeloid cells to the cornea in the chronic phase. Herpes virus entry mediator–associated corneal sensitivity loss preceded leukocytic infiltration, suggesting it may play an active role in recruitment. We propose that HVEM on resident corneal macrophages increases nerve damage and immune cell invasion, and we showed that prevention of late-phase infiltration of PMN and CD4+ T cells by IMP therapy improved clinical symptoms and mortality and reduced corneal sensitivity loss caused by HSV-1. PMID:28114589

  8. [Developments in corneal transplants: lamellar techniques emerging].

    PubMed

    Steijns, Daan; Bral, Nathalie; Tang, Mei Lie; van der Lelij, Allegonda

    2013-01-01

    Corneal transplants are the most frequently performed human transplant procedure. In the last decade, we have seen large developments in the field of corneal transplant surgery. Currently, several techniques are being used in the Netherlands, each with its own advantages and disadvantages and with distinct indications. In penetrating keratoplasty all layers of the cornea are replaced by a donor cornea. In so-called lamellar corneal transplantation only the affected layer of the cornea is replaced by donor tissue. The developments in corneal transplantation surgery have resulted in an improved prognosis in terms of vision and fewer complications.

  9. Central Corneal Thickness in Children

    PubMed Central

    2011-01-01

    Objective To report the central corneal thickness (CCT) in healthy white, African-American, and Hispanic children from birth to 17 years of age. Design Prospective observational multicenter study. Central corneal thickness was measured with a hand-held contact pachymeter. Results Two thousand seventy-nine children were included in the study, with ages ranging from day of birth to 17 years. Included were 807 white, 494 Hispanic, and 474 African-American individuals, in addition to Asian, unknown and mixed race individuals. African-American children had thinner corneas on average than that of both white (p< .001) and Hispanic children (p< .001) by approximately 20 micrometers. Thicker median CCT was observed with each successive year of age from age 1 to 11 years, with year-to-year differences steadily decreasing and reaching a plateau after age 11 at 573 micrometers in white and Hispanic children and 551 micrometers in African-American children. For every 100 micrometers of thicker CCT measured, the intraocular pressure was 1.5 mmHg higher on average (p< 0.001). For every diopter of increased myopic refractive error (p< 0.001) CCT was 1 micrometer thinner on average. Conclusions Median CCT increases with age from 1 to 11 years with the greatest increase present in the youngest age groups. African-American children on average have thinner central corneas than white and Hispanic children, while white and Hispanic children demonstrate similar central corneal thickness. PMID:21911662

  10. Intrauterine blood transfusion in immune hydrops fetalis, corrects middle cerebral artery Doppler velocimetry very quickly

    PubMed Central

    Yalinkaya, Ahmet; Evsen, Mehmet Sıddık; Celik, Yusuf; Sak, Muhammet Erdal; Soydinc, Hatice Ender; Taner, Mehmet Zeki

    2012-01-01

    The aim of our study was to evaluate the middle cerebral artery velocimetry before and after intrauterine blood transfusion in immune hydrops fetalis. The current study was conducted in a tertiary research hospital, from February 2009 to January 2011. Nineteen intrauterine blood transfusions performed during the study period. The factors recorded were age of the mothers, gestational weeks, pre-transfusion fetal hematocrit and post-transfusion fetal hematocrit, and also middle cerebral artery peak systolic velocimetry (MCA-PSV) was detected and recorded before and after intrauterine transfusion. A control group of twenty two cases for normal MCA doppler velocimetry was also included to the study. During the study, a total of eleven rhesus isoimmunized pregnancies underwent intrauterine blood transfusions at our perinatal diagnose unit. Before transfusion seventeen severe and two moderate anemias were detected and mean MoM of MCA-PSV was 1.76±0.38 MoM. Post transfusion mean MoM of MCA-PSV in the patient group and control group were 1.08±0.22 MoM and 0.96±0.21 MoM, respectively. The mean MCA-PSV values were higher in RI fetuses than post transfusion and control group. In current study, we found that MCA-PSV is a valuable parameter in detecting fetal anemia requiring intrauterine transfusion and mean MCA-PSV values is higher than 1.5 MoM in fetuses with anemia. And also decrease in MCA-PSV just after transfusion in anemic fetuses showed the quick response of the fetus to correction of anemia. PMID:22364302

  11. Infantile lethal variant of Simpson-Golabi-Behmel syndrome associated with hydrops fetalis

    SciTech Connect

    Terespolsky, D.; Siegel-Bartelt, J.; Weksberg, R.; Farrell, S.A.

    1995-11-20

    Simpson-Golabi Behmel syndrome (SGBS) is an X-linked disorder characterized by pre- and postnatal macrosomia, minor facial anomalies, and variable visceral, skeletal, and neurological abnormalities. Since its first description by Simpson et al., a wide clinical range of cases has been reported. There is great variability in severity, ranging from a mild form associated with long-term survival to an early lethal form with multiple congenital anomalies and severe mental retardation. In 8 reported families, affected individuals died in infancy. Here we present 4 maternally related, male cousins with a severe variant of SGBS. One of these males was aborted therapeutically at 19 weeks of gestation following the detection of multicystic kidneys on ultrasound. The 3 liveborn males were hydropic at birth with a combination of craniofacial anomalies including macrocephaly; apparently low-set, posteriorly angulated ears; hypertelorism; short, broad nose with anteverted nares; large mouth with thin upper vermilion border; prominent philtrum; high-arched or cleft palate; short neck; redundant skin; hypoplastic nails; skeletal defects involving upper and lower limbs; gastrointestinal and genitourinary anomalies. All 3 patients were hypotonic and neurologically impaired from birth. With the exception of a trilobate left lung in one patient, the cardiorespiratory system was structurally normal. All patients died within the first 8 weeks of life of multiple complications including pneumonia and sepsis. Two SGBS kindreds, with moderate expression of the condition, have been mapped to Xq27. It is not known whether severe, familiar cases, such as ours, are genetically distinct from and map to another locus. Final resolution of the genetic basis of the phenotypic variability in SGBS must await cloning and mutation analysis of the SGBS gene(s). 21 refs., 4 figs., 1 tab.

  12. Dehydration effects of a V2 antagonist on endolymphatic hydrops in guinea pigs.

    PubMed

    Egami, Naoya; Kakigi, Akinobu; Takeda, Taizo; Yamasoba, Tatsuya

    2016-02-01

    We investigated the influence of vasopressin type 2 receptor antagonist (OPC-41061; Tolvaptan) on experimentally induced endolymphatic hydrops (EH) in guinea pigs. In the first series, the endolymphatic sac (ES) of the left ear of all animals was electrocauterized. Four weeks after surgery, the animals were allocated to four groups: three systemic applications groups (saline, OPC 10 and 100 mg/kg) and a local round window (RW) OPC 1 mg/body application group. We examined the histopathology of the temporal bones and assessed volumetric changes of the endolymphatic space in the cochlea and saccule. In the second series, we investigated the effects of systemic and topical applications of OPC on plasma vasopressin (p-VP) concentrations and plasma osmolality (p-OSM). In the first series, we found that EH was reduced in the OPC 10 mg/kg systemic and OPC RW application groups. In contrast, EH increased in the OPC 100 mg/kg systemic application group. In the second series, neither p-VP levels nor p-OSM were significantly different among the non-OPC, OPC 10 mg/kg systemic, and OPC RW application groups. However, in the OPC 100 mg/kg systemic application group, the p-VP level was significantly higher than that in other groups, and p-OSM was higher than that in the non-OPC group. The systemic application of a low dose of OPC and topical application of OPC resulted in reduced EH in the face of minimal systemic effects (p-VP and p-OSM). These findings suggest that OPC-41061 may be one useful treatment option for EH.

  13. Hydrops associated with chondrodysplasia of the fetus in a miniature Scottish Highland cow.

    PubMed

    Catalina Cabrera, L; McNabb, Bret R; Woods, Sarah E; Cartoceti, Andrew N; Busch, Rosie C

    2016-03-01

    CASE DESCRIPTION A 2-year-old primiparous miniature Scottish Highland cow with an unknown breeding date was evaluated for suspected hydrops. CLINICAL FINDINGS Transabdominal and transrectal ultrasonographic examination identified a large amount of hypoechoic fluid within an enlarged uterus; the fetus could not be identified. Presence of a severely distended uterus and concerns regarding associated health risks to the cow led to the decision to induce labor. Although fluids were expelled, parturition did not progress further over the following 48 hours. Vaginal examination revealed a partially dilated cervix and an abnormally shaped fetus that was too large to pass vaginally. TREATMENT AND OUTCOME Supportive care was provided to the cow, and a stillborn bull calf was delivered by cesarean section. Grossly evident chondrodystrophic dwarfism with hydrocephalus, compatible with so-called bulldog calf malformations, was confirmed by diagnostic imaging and histopathologic evaluation. The cow recovered from surgery uneventfully and was discharged from the hospital the following day. Genetic analysis of DNA from hair roots collected from the sire and dam confirmed both were carriers of an aggrecan-1 gene mutation (bulldog dwarfism1) previously associated with dwarfism and bulldog calf malformations in Dexter cattle. CLINICAL RELEVANCE To our knowledge, this is the first reported case of bulldog calf malformations associated with an aggrecan-1 gene mutation in miniature Scottish Highland cattle, confirming that at least 1 genetic mutation associated with this condition is found in cattle breeds other than Dexter. The findings highlighted the clinical importance of testing for known genetic diseases in breeding cattle, particularly among miniature breeds.

  14. Assessment and management of patients with acute red eye.

    PubMed

    Watkinson, Sue

    2013-06-01

    This article provides an overview of the role of the nurse in the assessment and management of five ocular conditions that give rise to an acute red eye in older people. The conditions discussed are acute closed angle glaucoma, acute iritis, acute conjunctivitis, herpes zoster ophthalmicus and bacterial corneal ulcer.

  15. Corneal Donor Tissue Preparation for Endothelial Keratoplasty

    PubMed Central

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

    2012-01-01

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

  16. Molecular analysis of patients with beta-glucuronidase deficiency presenting as hydrops fetalis or as early mucopolysaccharidosis VII.

    PubMed

    Vervoort, R; Islam, M R; Sly, W S; Zabot, M T; Kleijer, W J; Chabas, A; Fensom, A; Young, E P; Liebaers, I; Lissens, W

    1996-03-01

    Although not all mucopolysaccharidosis type VII (MPS VII) neonates present with hydrops fetalis or with related symptoms, hydrops fetalis is a common form of presentation of this mucopolysaccharidosis. We used reverse-transcription-PCR-SSCP and direct sequencing to screen for mutations in the human beta-glucuronidase cDNA of 17 MPS VII patients with severe presentation of the disease. Mutations resulting in an unstable mRNA were detected in genomic DNA with direct sequencing of the PCR-amplified beta-glucuronidase exons. We found extensive genetic heterogeneity in MPS VII alleles: in addition to 6 or 12 previously reported mutations (L176F, R216W, R357X, R382C, W507X, and W627C), we detected 14 undescribed mutations in the beta-glucuronidase coding region that produce MPS VII alleles (G136R, E150K, S312X, Y320S, Y320C, H351Y, R382H, R374C, R435P, R477W, G572D, Y508C, K606N and 1900 delta GA). The mutations in hydropic fetuses were widely scattered in the beta-glucuronidase gene. Analysis of three polymorphic sites of the mutant alleles (1766T/C, 1972C/T and a new 1091+27C/G polymorphism) allowed exclusion of identity by descent for some recurrent mutations. Three of four mutations introducing a premature translation stop codon were found to affect mRNA abundance and/or structure. Expression studies provided evidence for the causal relationship between each of the mutations found in MPS VII alleles and the enzyme deficiency, in that all mutations identified exhibited markedly reduced enzyme activity expressed in COS7 cells following transfection with the mutant cDNA.

  17. Molecular analysis of patients with beta-glucuronidase deficiency presenting as hydrops fetalis or as early mucopolysaccharidosis VII.

    PubMed Central

    Vervoort, R.; Islam, M. R.; Sly, W. S.; Zabot, M. T.; Kleijer, W. J.; Chabas, A.; Fensom, A.; Young, E. P.; Liebaers, I.; Lissens, W.

    1996-01-01

    Although not all mucopolysaccharidosis type VII (MPS VII) neonates present with hydrops fetalis or with related symptoms, hydrops fetalis is a common form of presentation of this mucopolysaccharidosis. We used reverse-transcription-PCR-SSCP and direct sequencing to screen for mutations in the human beta-glucuronidase cDNA of 17 MPS VII patients with severe presentation of the disease. Mutations resulting in an unstable mRNA were detected in genomic DNA with direct sequencing of the PCR-amplified beta-glucuronidase exons. We found extensive genetic heterogeneity in MPS VII alleles: in addition to 6 or 12 previously reported mutations (L176F, R216W, R357X, R382C, W507X, and W627C), we detected 14 undescribed mutations in the beta-glucuronidase coding region that produce MPS VII alleles (G136R, E150K, S312X, Y320S, Y320C, H351Y, R382H, R374C, R435P, R477W, G572D, Y508C, K606N and 1900 delta GA). The mutations in hydropic fetuses were widely scattered in the beta-glucuronidase gene. Analysis of three polymorphic sites of the mutant alleles (1766T/C, 1972C/T and a new 1091+27C/G polymorphism) allowed exclusion of identity by descent for some recurrent mutations. Three of four mutations introducing a premature translation stop codon were found to affect mRNA abundance and/or structure. Expression studies provided evidence for the causal relationship between each of the mutations found in MPS VII alleles and the enzyme deficiency, in that all mutations identified exhibited markedly reduced enzyme activity expressed in COS7 cells following transfection with the mutant cDNA. Images Figure 2 Figure 3A Figure 3BC Figure 4 PMID:8644704

  18. Early-onset fetal hydrops and muscle degeneration in siblings due to a novel variant of type IV glycogenosis.

    PubMed

    Cox, P M; Brueton, L A; Murphy, K W; Worthington, V C; Bjelogrlic, P; Lazda, E J; Sabire, N J; Sewry, C A

    1999-09-10

    We report on 3 consecutive sib fetuses, presenting at 13, 12, and 13 weeks of gestation, respectively, with fetal hydrops, limb contractures, and akinesia. Autopsy of the first fetus showed subcutaneous fluid collections and severe degeneration of skeletal muscle. Histologic studies demonstrated massive accumulation of diastase-resistant periodic acid-Schiff-positive material in the skeletal muscle cells and epidermal keratinocytes of all 3 fetuses. Enzyme studies of fibroblasts from the 3rd fetus showed deficient activity of glycogen brancher enzyme, indicating that this is a new, severe form of glycogenosis type IV with onset in the early second trimester.

  19. Corneal topography and the hirschberg test.

    PubMed

    Brodie, S E

    1992-07-01

    A simple trigonometric analysis of the Hirschberg test with the assumption that the corneal surface is spherical predicts a sinusoidal dependence of the corneal reflex displacement on the angle of ocular rotation. A comparison with corneal reflex photographs demonstrates that at angles larger than 50 prism diopters (26 deg) the reflex displacements are larger than predicted by the spherical model. This discrepancy may be accounted for by incorporating a more general description of the corneal topography into the geometric analysis. The linear Hirschberg relation that is seen in typical data is accounted for by a relative flattening of the peripheral cornea by ~ 20% of the apical curvature. This geometric analysis of the functional dependence of the Hirschberg relation on the corneal topography can be expressed as an integral equation. Differentiation yields a second-order differential equation for the corneal topography in terms of the Hirschberg data. If the Hirschberg relation is assumed to be linear, a quadratic dependence is found for the corneal curvature. A similar differential approach can be formulated for the Placido disk. In this sense the corneal topography problem given in terms of Placido disk data is shown to be wellformulated. The relative simplicity of the Hirschberg geometry is seen to stem from the alignment of the light source with the eye of the observer.

  20. Corneal hysteresis and its relevance to glaucoma

    PubMed Central

    Deol, Madhvi; Taylor, David A.; Radcliffe, Nathan M.

    2015-01-01

    Purpose of review Glaucoma is a leading cause of irreversible blindness worldwide. It is estimated that roughly 60.5 million people had glaucoma in 2010 and that this number is increasing. Many patients continue to lose vision despite apparent disease control according to traditional risk factors. The purpose of this review is to discuss the recent findings with regard to corneal hysteresis, a variable that is thought to be associated with the risk and progression of glaucoma. Recent findings Low corneal hysteresis is associated with optic nerve and visual field damage in glaucoma and the risk of structural and functional glaucoma progression. In addition, hysteresis may enhance intraocular pressure (IOP) interpretation: low corneal hysteresis is associated with a larger magnitude of IOP reduction following various glaucoma therapies. Corneal hysteresis is dynamic and may increase in eyes after IOP-lowering interventions are implemented. Summary It is widely accepted that central corneal thickness is a predictive factor for the risk of glaucoma progression. Recent evidence shows that corneal hysteresis also provides valuable information for several aspects of glaucoma management. In fact, corneal hysteresis may be more strongly associated with glaucoma presence, risk of progression, and effectiveness of glaucoma treatments than central corneal thickness. PMID:25611166

  1. Dense peripheral corneal clouding in Scheie syndrome.

    PubMed

    Summers, C G; Whitley, C B; Holland, E J; Purple, R L; Krivit, W

    1994-05-01

    A 28-year-old woman with Scheie syndrome (MPS I-S) presented with the unusual feature of extremely dense peripheral corneal clouding, allowing maintenance of good central visual acuity. Characteristic systemic features, an abnormal electroretinogram result, and absent alpha-L-iduronidase activity confirmed the diagnosis despite the unusual corneal pattern of clouding.

  2. Do topical antibiotics help corneal epithelial trauma?

    PubMed Central

    King, J. W.; Brison, R. J.

    1993-01-01

    Topical antibiotics are routinely used in emergency rooms to treat corneal trauma, although no published evidence supports this treatment. In a noncomparative clinical trial, 351 patients with corneal epithelial injuries were treated without antibiotics. The infection rate was 0.7%, suggesting that such injuries can be safely and effectively managed without antibiotics. A comparative clinical trial is neither warranted nor feasible. PMID:8268742

  3. Corneal autofluorescence in presence of diabetic retinopathy

    NASA Astrophysics Data System (ADS)

    Rovati, Luigi; Docchio, Franco; Azzolini, Claudio; Van Best, Jaap A.

    1998-06-01

    Recently corneal autofluorescence has been proposed as an ocular diagnostic tool for diabetic retinopathy. The method is based on the sensible increase of the natural fluorescence of corneal tissue within specific wavelength in presence of early stage of diabetic retinopathy. The main advantages of this method are that the corneal autofluorescence has been demonstrated to be not age-related and that the cornea is readily accessible to be investigated. In this study 47 insulin-dependent diabetes mellitus and 51 non-insulin- dependent diabetes mellitus patients aged 20 - 90 years have been considered. Patients were selected from the Eye Clinic of S. Raffaele Hospital. The modified Airlie House classification was used to grade the diabetic retinopathy. Corneal autofluorescence has been measured by using both a specifically designed instrument and the Fluorotron Master. Corneal autofluorescence mean value for each diabetic retinopathy measured by using both the instruments correlated with the retinopathy grade.

  4. Keratoconus and related noninflammatory corneal thinning disorders.

    PubMed

    Krachmer, J H; Feder, R S; Belin, M W

    1984-01-01

    Keratoconus and other noninflammatory corneal thinning disorders (keratoglobus, pellucid marginal degeneration and posterior keratoconus) are characterized by progressive corneal thinning, protrusion and scarring; the result is distorted and decreased vision. The etiology and pathogenesis of these disorders are unknown but may be associated with a variety of factors, including contact lens wear, eye rubbing, Down's syndrome, atopic disease, connective tissue disease, tapetoretinal degeneration and inheritance. Recent advances in techniques for biochemical and pathological investigation are now allowing further exploration in these areas. Early diagnosis is aided by the finding of irregular corneal astigmatism with inferior corneal steepening. Treatment ranges from simple spectacle correction to keratoplasty. In this review, the past and present literature on corneal thinning disorders is reviewed and practical approaches to diagnosis and management are outlined.

  5. Corneal biomechanical properties in thyroid eye disease.

    PubMed

    Karabulut, Gamze Ozturk; Kaynak, Pelin; Altan, Cıgdem; Ozturker, Can; Aksoy, Ebru Funda; Demirok, Ahmet; Yılmaz, Omer Faruk

    2014-06-01

    The purpose of this study is to investigate the effect of thyroid eye disease (TED) on the measurement of corneal biomechanical properties and the relationship between these parameters and disease manifestations. A total of 54 eyes of 27 individuals with TED and 52 eyes of 30 healthy control participants were enrolled. Thyroid ophthalmopathy activity was defined using the VISA (vision, inflammation, strabismus, and appearance/exposure) classification for TED. The intraocular pressure (IOP) measurement with Goldmann applanation tonometer (GAT), axial length (AL), keratometry, and central corneal thickness (CCT) measurements were taken from each patient. Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF) and noncontact IOP measurements, Goldmann-correlated IOP (IOPg) and corneal-compensated IOP (IOPcc) were measured with the Ocular Response Analyzer (ORA) using the standard technique. Parameters such as best corrected visual acuity, axial length, central corneal thickness, and corneal curvature were not statistically significant between the two groups (p > 0.05). IOP measured with GAT was higher in participants with TED (p < 0.001). The CH of TED patients was significantly lower than that of the control group. There was no significant difference in the corneal resistance factor between groups. However, IOPg and IOPcc were significantly higher in TED patients. CH and VISA grading of TED patients showed a negative correlation (p = 0.007). In conclusion, TED affects the corneal biomechanical properties by decreasing CH. IOP with GAT and IOPg is found to be increased in these patients. As the severity of TED increases, CH decreases in these patients.

  6. Corneal endothelium: developmental strategies for regeneration.

    PubMed

    Zavala, J; López Jaime, G R; Rodríguez Barrientos, C A; Valdez-Garcia, J

    2013-05-01

    The main treatment available for restoration of the corneal endothelium is keratoplasty. This procedure is faced with several difficulties, including the shortage of donor tissue, post-surgical complications associated with the use of drugs to prevent immune rejection, and a significant increase in the occurrence of glaucoma. Recently, surgical procedures such as Descemet's stripping endothelial keratoplasty have focused on the transplant of corneal endothelium, yielding better visual results but still facing the need for donor tissue. The emergent strategies in the field of cell biology and tissue cultivation of corneal endothelial cells aim at the production of transplantable endothelial cell sheets. Cell therapy focuses on the culture of corneal endothelial cells retrieved from the donor, in the donor's cornea, followed by transplantation into the recipient. Recently, research has focused on overcoming the challenge of harvesting human corneal endothelial cells and the generation of new biomembranes to be used as cell scaffolds in surgical procedures. The use of corneal endothelial precursors from the peripheral cornea has also demonstrated to be effective and represents a valuable tool for reducing the risk of rejection in allogeneic transplants. Several animal model reports also support the use of adult stem cells as therapy for corneal diseases. Current results represent important progresses in the development of new strategies based on alternative sources of tissue for the treatment of corneal endotheliopathies. Different databases were used to search literature: PubMed, Google Books, MD Consult, Google Scholar, Gene Cards, and NCBI Books. The main search terms used were: 'cornea AND embryology AND transcription factors', 'human endothelial keratoplasty AND risk factors', '(cornea OR corneal) AND (endothelium OR endothelial) AND cell culture', 'mesenchymal stem cells AND cell therapy', 'mesenchymal stem cells AND cornea', and 'stem cells AND (cornea OR

  7. Corneal Regeneration by Deep Anterior Lamellar Keratoplasty (DALK) Using Decellularized Corneal Matrix

    PubMed Central

    Hashimoto, Yoshihide; Funamoto, Seiichi; Sasaki, Shuji; Negishi, Jun; Honda, Takako; Hattori, Shinya; Nam, Kwangwoo; Kimura, Tsuyoshi; Mochizuki, Manabu; Kobayashi, Hisatoshi; Kishida, Akio

    2015-01-01

    The purpose of this study is to demonstrate the feasibility of DALK using a decellularized corneal matrix obtained by HHP methodology. Porcine corneas were hydrostatically pressurized at 980 MPa at 10°C for 10 minutes to destroy the cells, followed by washing with EGM-2 medium to remove the cell debris. The HHP-treated corneas were stained with H-E to assess the efficacy of decellularization. The decellularized corneal matrix of 300 μm thickness and 6.0 mm diameter was transplanted onto a 6.0 mm diameter keratectomy wound. The time course of regeneration on the decellularized corneal matrix was evaluated by haze grading score, fluorescein staining, and immunohistochemistry. H-E staining revealed that no cell nuclei were observed in the decellularized corneal matrix. The decellularized corneal matrices were opaque immediately after transplantation, but became completely transparent after 4 months. Fluorescein staining revealed that initial migration of epithelial cells over the grafts was slow, taking 3 months to completely cover the implant. Histological sections revealed that the implanted decellularized corneal matrix was completely integrated with the receptive rabbit cornea, and keratocytes infiltrated into the decellularized corneal matrix 6 months after transplantation. No inflammatory cells such as macrophages, or neovascularization, were observed during the implantation period. The decellularized corneal matrix improved corneal transparency, and remodelled the graft after being transplanted, demonstrating that the matrix obtained by HHP was a useful graft for corneal tissue regeneration. PMID:26161854

  8. Therapeutic efficiency of tissue-engineered human corneal endothelium transplants on rabbit primary corneal endotheliopathy.

    PubMed

    Fan, Ting-jun; Zhao, Jun; Hu, Xiu-zhong; Ma, Xi-ya; Zhang, Wen-bo; Yang, Chao-zhong

    2011-06-01

    To evaluate the therapeutic efficiency of tissue-engineered human corneal endothelia (TE-HCEs) on rabbit primary corneal endotheliopathy (PCEP), TE-HCEs reconstructed with monoclonal human corneal endothelial cells (mcHCECs) and modified denuded amniotic membranes (mdAMs) were transplanted into PCEP models of New Zealand white rabbits using penetrating keratoplasty. The TE-HCEs were examined using diverse techniques including slit-lamp biomicroscopy observation and pachymeter and tonometer measurements in vivo, and fluorescent microscopy, alizarin red staining, paraffin sectioning, scanning and transmission electron microscopy observations in vitro. The corneas of transplanted eyes maintained transparency for as long as 200 d without obvious edema or immune rejection. The corneal thickness of transplanted eyes decreased gradually after transplanting, reaching almost the thickness of normal eyes after 156 d, while the TE-HCE non-transplanted eyes were turbid and showed obvious corneal edema. The polygonal corneal endothelial cells in the transplanted area originated from the TE-HCE transplant. An intact monolayer corneal endothelium had been reconstructed with the morphology, cell density and structure similar to those of normal rabbit corneal endothelium. In conclusion, the transplanted TE-HCE can reconstruct the integrality of corneal endothelium and restore corneal transparency and thickness in PCEP rabbits. The TE-HCE functions normally as an endothelial barrier and pump and promises to be an equivalent of HCE for clinical therapy of human PCEP.

  9. Potential role of corneal epithelial cell-derived exosomes in corneal wound healing and neovascularization

    PubMed Central

    Han, Kyu-Yeon; Tran, Jennifer A.; Chang, Jin-Hong; Azar, Dimitri T.; Zieske, James D.

    2017-01-01

    Specific factors from the corneal epithelium underlying the stimulation of stromal fibrosis and myofibroblast formation in corneal wound healing have not been fully elucidated. Given that exosomes are known to transfer bioactive molecules among cells and play crucial roles in wound healing, angiogenesis, and cancer, we hypothesized that corneal epithelial cell-derived exosomes may gain access to the underlying stromal fibroblasts upon disruption of the epithelial basement membrane and that they induce signaling events essential for corneal wound healing. In the present study, exosome-like vesicles were observed between corneal epithelial cells and the stroma during wound healing after corneal epithelial debridement. These vesicles were also found in the stroma following anterior stromal keratectomy, in which surgical removal of the epithelium, basement membrane, and anterior stroma was performed. Exosomes secreted by mouse corneal epithelial cells were found to fuse to keratocytes in vitro and to induce myofibroblast transformation. In addition, epithelial cell-derived exosomes induced endothelial cell proliferation and ex vivo aortic ring sprouting. Our results indicate that epithelial cell-derived exosomes mediate communication between corneal epithelial cells and corneal keratocytes as well as vascular endothelial cells. These findings demonstrate that epithelial-derived exosomes may be involved in corneal wound healing and neovascularization, and thus, may serve as targets for potential therapeutic interventions. PMID:28165027

  10. Corneal modeling for analysis of photorefractive keratectomy

    NASA Astrophysics Data System (ADS)

    Della Vecchia, Michael A.; Lamkin-Kennard, Kathleen

    1997-05-01

    Procedurally, excimer photorefractive keratectomy is based on the refractive correction of composite spherical and cylindrical ophthalmic errors of the entire eye. These refractive errors are inputted for correction at the corneal plane and for the properly controlled duration and location of laser energy. Topography is usually taken to correspondingly monitor spherical and cylindrical corneorefractive errors. While a corneal topographer provides surface morphologic information, the keratorefractive photoablation is based on the patient's spherical and cylindrical spectacle correction. Topography is at present not directly part of the procedural deterministic parameters. Examination of how corneal curvature at each of the keratometric reference loci affect the shape of the resultant corneal photoablated surface may enhance the accuracy of the desired correction. The objective of this study was to develop a methodology to utilize corneal topography for construction of models depicting pre- and post-operative keratomorphology for analysis of photorefractive keratectomy. Multiple types of models were developed then recreated in optical design software for examination of focal lengths and other optical characteristics. The corneal models were developed using data extracted from the TMS I corneal modeling system (Computed Anatomy, New York, NY). The TMS I does not allow for manipulation of data or differentiation of pre- and post-operative surfaces within its platform, thus models needed to be created for analysis. The data were imported into Matlab where 3D models, surface meshes, and contour plots were created. The data used to generate the models were pre- and post-operative curvatures, heights from the corneal apes, and x-y positions at 6400 locations on the corneal surface. Outlying non-contributory points were eliminated through statistical operations. Pre- and post- operative models were analyzed to obtain the resultant changes in the corneal surfaces during PRK

  11. Kinetics of corneal thermal shrinkage

    NASA Astrophysics Data System (ADS)

    Borja, David; Manns, Fabrice; Lee, William E.; Parel, Jean-Marie

    2004-07-01

    Purpose: The purpose of this study was to determine the effects of temperature and heating duration on the kinetics of thermal shrinkage in corneal strips using a custom-made shrinkage device. Methods: Thermal shrinkage was induced and measured in corneal strips under a constant load placed while bathed in 25% Dextran irrigation solution. A study was performed on 57 Florida Lions Eye Bank donated human cadaver eyes to determine the effect of temperature on the amount and rate of thermal shrinkage. Further experiments were performed on 20 human cadaver eyes to determine the effects of heating duration on permanent shrinkage. Data analysis was performed to determine the effects of temperature, heating duration, and age on the amount and kinetics of shrinkage. Results: Shrinkage consisted of two phases: a shrinkage phase during heating and a regression phase after heating. Permanent shrinkage increased with temperature and duration. The shrinkage and regression time constants followed Arrhenius type temperature dependence. The shrinkage time constants where calculated to be 67, 84, 121, 560 and 1112 (s) at 80, 75, 70, 65, and 60°C respectively. At 65°C the permanent shrinkage time constant was calculated to be 945s. Conclusion: These results show that shrinkage treatments need to raise the temperature of the tissue above 75°C for several seconds in order to prevent regression of the shrinkage effect immediately after treatment and to induce the maximum amount of permanent irreversible shrinkage.

  12. Corneal laceration caused by river crab

    PubMed Central

    Vinuthinee, Naidu; Azreen-Redzal, Anuar; Juanarita, Jaafar; Zunaina, Embong

    2015-01-01

    A 5-year-old boy presented with right eye pain associated with tearing and photophobia of 1-day duration. He gave a history of playing with a river crab when suddenly the crab clamped his fingers. He attempted to fling the crab off, but the crab flew and hit his right eye. Ocular examination revealed a right eye corneal ulcer with clumps of fibrin located beneath the corneal ulcer and 1.6 mm level of hypopyon. At presentation, the Seidel test was negative, with a deep anterior chamber. Culture from the corneal scrapping specimen grew Citrobacter diversus and Proteus vulgaris, and the boy was treated with topical gentamicin and ceftazidime eyedrops. Fibrin clumps beneath the corneal ulcer subsequently dislodged, and revealed a full-thickness corneal laceration wound with a positive Seidel test and shallow anterior chamber. The patient underwent emergency corneal toileting and suturing. Postoperatively, he was treated with oral ciprofloxacin 250 mg 12-hourly for 1 week, topical gentamicin, ceftazidime, and dexamethasone eyedrops for 4 weeks. Right eye vision improved to 6/9 and 6/6 with pinhole at the 2-week follow-up following corneal suture removal. PMID:25678769

  13. Differences between real and predicted corneal shapes after aspherical corneal ablation

    NASA Astrophysics Data System (ADS)

    Anera, Rosario G.; Villa, César; Jiménez, José R.; Gutiérrez, Ramón; Jiménez del Barco, Luis

    2005-07-01

    We study the differences between real and expected corneal shapes, using an aspherical ablation algorithm with a known equation and avoiding the limitation imposed by most studies of refractive surgery in which the ablation equations are not known. We have calculated the theoretical corneal shape predicted by this algorithm, comparing this shape with the real corneal topography. The results indicate that the deviations that appear in the corneal shape are significant for visual performance and for the correction of eye aberrations. If we include in this analysis the effect of reflection losses and nonnormal incidence on the cornea, we can reduce corneal differences, but they will remain significant. These results confirm that it is essential to minimize corneal differences to achieve effective correction in refractive surgery.

  14. Technology needs for corneal transplant surgery

    NASA Astrophysics Data System (ADS)

    Vaddavalli, Pravin K.; Yoo, Sonia H.

    2011-03-01

    Corneal transplant surgery has undergone numerous modifications over the years with improvements in technique, instrumentation and eye banking. The main goals of corneal transplantation are achieving excellent optical clarity with long-term graft survival. Penetrating, anterior and posterior lamellar surgery along with femtosecond laser technology have partially met these goals, but outcomes are often unpredictable and surgeon dependent. Technology to predictably separate stroma from Descemet's membrane, techniques to minimize endothelial cell loss, improvements in imaging technology and emerging techniques like laser welding that might replace suturing, eventually making corneal transplantation a refractively predictable procedure are on the wish list of the cornea surgeon.

  15. Monoclonal corneal gammopathy: topographic considerations.

    PubMed

    Sekundo, W; Seifert, P

    1996-09-01

    Desposition of immunoglobulins in the cornea occasionally occurs in benign and malignant lymphoproliferative conditions. A 52-year-old woman with recently discovered monoclonal gammopathy of undetermined significance (MGUS) was referred to our hospital. Slit-lamp and ultrasound biomicroscopy revealed bilateral deposits within all corneal layers. The precipitates were organized in a circle, leaving a perilimbal zone and the axial cornea clear. Light microscopy of a biopsy disclosed confluent subepithelial deposits and defects in Bowman's layer. Immunoperoxidase reaction was positive only for IgG and IgG-kappa. Transmission electron microscopy confirmed the presence of extracellular rectangular and arcuate immunoglobulin crystalloids with a 10-nm periodicity but a non-crystalline defraction pattern. A review of the literature showed that the circumferential pattern of immunoglobulin deposition is associated with short-term visual symptoms and good visual acuity. The present report supports a hypothesis of immunoglobulin deposition via the limbal arcade and contradicts the "tear theory."

  16. Clear Corneal Incision in Cataract Surgery

    PubMed Central

    Al Mahmood, Ammar M.; Al-Swailem, Samar A.; Behrens, Ashley

    2014-01-01

    Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature. PMID:24669142

  17. Genetics Home Reference: congenital stromal corneal dystrophy

    MedlinePlus

    ... an irregular surface. These corneal changes lead to visual impairment, including blurring, glare, and a loss of sharp vision (reduced visual acuity). Visual impairment is often associated with additional ...

  18. Negative dysphotopsia after temporal corneal incisions.

    PubMed

    Cooke, David L

    2010-04-01

    Temporal incisions made during cataract extraction have been purported to cause negative dysphotopsia. A case in which negative dysphotopsia occurred after superior scleral tunnel incisions is described. The dystopsia symptoms resolved immediately after intraocular lens exchange using temporal corneal incisions.

  19. The genetics of Fuchs′ corneal dystrophy

    PubMed Central

    Iliff, Benjamin W; Riazuddin, S Amer; Gottsch, John D

    2013-01-01

    Fuchs′ corneal dystrophy (FCD) is a common late-onset genetic disorder of the corneal endothelium. It causes loss of endothelial cell density and excrescences in the Descemet membrane, eventually progressing to corneal edema, necessitating corneal transplantation. The genetic basis of FCD is complex and heterogeneous, demonstrating variable expressivity and incomplete penetrance. To date, three causal genes, ZEB1, SLC4A11 and LOXHD1, have been identified, representing a small proportion of the total genetic load of FCD. An additional four loci have been localized, including a region on chromosome 18 that is potentially responsible for a large proportion of all FCD cases. The elucidation of the causal genes underlying these loci will begin to clarify the pathogenesis of FCD and pave the way for the emergence of nonsurgical treatments. PMID:23585771

  20. Rare case of massive congenital bilateral chylothorax in a hydropic fetus with true mosaicism 47,XXX/46,XX.

    PubMed

    Cremonini, Giorgio; Poggi, Alice; Capucci, Roberta; Vesce, Fortunato; Patella, Alfredo; Marci, Roberto

    2014-01-01

    Fetal congenital chylothorax is a rare condition that occurs sporadically or can be associated with abnormal karyotype or structural chromosomal anomalies. We report a unique case of fetal congenital bilateral chylothorax associated with mosaicism 47,XXX/46,XX. A female fetus affected by massive bilateral hydrothorax and ascites was diagnosed at 34(+1) weeks of gestation. Previous ultrasonographic exams were completely normal. Immune causes of hydrops were excluded. Elective cesarean section was performed soon after bilateral thoracocentesis. The analysis of drained pleural fluid revealed its lymphatic nature. The fetal karyotyping, performed on chorionic villi at the 11th week, had shown mosaicism 47,XXX/46,XX, later confirmed in the newborn's blood. We hypothesized that chylothorax may be part of the phenotypic spectrum of 47 XXX karyotype and we suggest an ultrasound follow-up of the fetus at closer intervals than the routine timing for this condition, even if it is not usually characterized by severe phenotypic features.

  1. Asphericity analysis using corneal wavefront and topographic meridional fits

    NASA Astrophysics Data System (ADS)

    Arba-Mosquera, Samuel; Merayo-Lloves, Jesús; de Ortueta, Diego

    2010-03-01

    The calculation of corneal asphericity as a 3-D fit renders more accurate results when it is based on the corneal wavefront aberrations rather than on the corneal topography of the principal meridians. A more accurate prediction could be obtained for hyperopic treatments compared to myopic treatments. We evaluate a method to calculate corneal asphericity and asphericity changes after refractive surgery. Sixty eyes of 15 consecutive myopic patients and 15 consecutive hyperopic patients (n=30 each) are retrospectively evaluated. Preoperative and 3-month-postoperative topographic and corneal wavefront analyses are performed using corneal topography. Ablations are performed using a laser with an aberration-free profile. Topographic changes in asphericity and corneal aberrations are evaluated for a 6-mm corneal diameter. The induction of corneal spherical aberrations and asphericity changes correlates with the achieved defocus correction. Preoperatively as well as postoperatively, asphericity calculated from the topography meridians correlates with asphericity calculated from the corneal wavefront in myopic and hyperopic treatments. A stronger correlation between postoperative asphericity and the ideally expected/predicted asphericity is obtained based on aberration-free assumptions calculated from corneal wavefront values rather than from the meridians. In hyperopic treatments, a better correlation can be obtained compared to the correlation in myopic treatments. Corneal asphericity calculated from corneal wavefront aberrations represents a 3-D fit of the corneal surface; asphericity calculated from the main topographic meridians represents a 2-D fit of the principal corneal meridians. Postoperative corneal asphericity can be calculated from corneal wavefront aberrations with higher fidelity than from corneal topography of the principal meridians. Hyperopic treatments show a greater accuracy than myopic treatments.

  2. Chlorpromazine-induced corneal endothelial phototoxicity

    SciTech Connect

    Hull, D.S.; Csukas, S.; Green, K.

    1982-04-01

    Chlorpromazine, which has been used extensively for the treatment of psychiatric disorders, is known to accumulate in the posterior corneal stroma, lens, and uveal tract. Because it is a phototoxic compound, the potential exists for it to cause cellular damage after light exposure. Specular microscopic perfusion of corneal endothelial cells in darkness with 0.5 mM chlorpromazine HCl resulted in a swelling rate of 18 +/- 2 micrometer/hr, whereas corneas exposed to long-wavelength ultraviolet light for 3 min in the presence of 0.5 mM chlorpromazine swelled at 37 +/- 9 micrometer/hr (p less than 0.01). Preirradiation of 0.5 mM chlorpromazine solution with ultraviolet light for 30 min and subsequent corneal perfusion with the solution resulted in a corneal swelling rate of 45 +/- 19 micrometer/hr. Cornea endothelial cells perfused with 0.5 mM chlorpromazine that was preirradiated with ultraviolet light showed marked swelling on scanning electron microscopic examination, whereas those perfused with nonirradiated chlorpromazine were flat and showed a normal mosaic pattern. Combining either 500 U/ml catalase or 290 U/ml superoxide dismutase with chlorpromazine did not alter photoinduction of corneal swelling. The data suggest that corneal endothelial chlorpromazine phototoxicity is secondary to cytotoxic products resulting from the photodynamically induced decomposition of chlorpromazine and is not caused by hydrogen peroxide or superoxide anion generated during the phototoxic reaction.

  3. Effluxing ABC Transporters in Human Corneal Epithelium

    PubMed Central

    Vellonen, Kati-Sisko; Mannermaa, Eliisa; Turner, Helen; Häkli, Marika; Wolosin, J. Mario; Tervo, Timo; Honkakoski, Paavo; Urtti, Arto

    2010-01-01

    ATP-binding cassette (ABC) transporters are able to efflux their substrate drugs from the cells. We compared expression of efflux proteins in normal human corneal epithelial tissue, primary human corneal epithelial cells (HCEpiC), and corneal epithelial cell culture model (HCE model) based on human immortal cell line. Expression of multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 1–6 (MRP1–6) and breast cancer resistance protein (BCRP) was studied using quantitative RT-PCR, Western blot, and immunohistochemistry. Only MRP1, MRP5, and BCRP were expressed in the freshly excised human corneal epithelial tissue. Expression of MRP1 and MRP5 was localized predominantly in the basal cells of the central cornea and limbus. Functional efflux activity was shown in the cell models, but they showed over-expression of most efflux transporters compared to that of normal corneal epithelium. In conclusion, MRP1, MRP5, and BCRP are expressed in the corneal epithelium, but MDR1, MRP2, MRP3, MRP4, and MRP6 are not significantly expressed. HCE cell model and commercially available primary cells deviate from this expression profile. PMID:19623615

  4. Effect of Endolymphatic Hydrops on Sound Transmission in Live Guinea Pigs Measured with a Laser Doppler Vibrometer

    PubMed Central

    Ding, Chen-Ru; Xu, Xin-Da; Wang, Xin-Wei; Jia, Xian-Hao; Cheng, Xiang; Liu, Xiang; Yang, Lin; Tong, Bu-Sheng

    2016-01-01

    Objective. This study aimed at describing the mechanism of hearing loss in low frequency and the different dynamic behavior of the umbo, the stapes head, and the round window membrane (RWM) between normal guinea pigs and those with endolymphatic hydrops (EH), using a laser Doppler vibrometer (LDV). Methods. Cochlear sections were stained with hematoxylin and eosin (HE) to evaluate the hydropic ratio (HR). Auditory brainstem responses (ABR) and whole-mount immunostaining were measured. Displacement of the umbo, stapes head, and RWM in response to ear-canal sound was evaluated using a LDV. Results. Mean HR values in EH model of all the turns are larger than the control group. The ABR threshold of the EH group was significantly higher than that of the control. Strong positive correlation was found between HR at apical turn and ABR threshold elevation at 1000 Hz and at subapical turn and ABR threshold elevation at 2000 Hz. FITC-phalloidin immunostaining of the cochlear basilar membrane in the apical, subapical, and suprabasal turns showed missing and derangement stereocilia of third-row outer hair cells. The umbo, stapes head, and RWM displacement in ears with EH was generally lower than that of normal ears. The EH-induced differences in stapes head and RWM motion were significant at 0.5 kHz. Conclusion. The LDV results suggested that the higher inner ear impedance in EH affected the dynamic behavior of the two opening windows of the cochlea and then reduced the vibration of the ossicular chain by increasing the afterload, resulting in acoustic dysfunction. The vibration reduction mainly occurred at low frequencies, which has related with the morphology changes of the apical and subapical turns in EH model. PMID:28090361

  5. Cultured corneal epithelia for ocular surface disease.

    PubMed Central

    Schwab, I R

    1999-01-01

    PURPOSE: To evaluate the potential efficacy for autologous and allogeneic expanded corneal epithelial cell transplants derived from harvested limbal corneal epithelial stem cells cultured in vitro for the management of ocular surface disease. METHODS: Human Subjects. Of the 19 human subjects included, 18 (20 procedures) underwent in vitro cultured corneal epithelial cell transplants using various carriers for the epithelial cells to determine the most efficacious approach. Sixteen patients (18 procedures on 17 eyes) received autologous transplants, and 2 patients (1 procedure each) received allogeneic sibling grafts. The presumed corneal epithelial stem cells from 1 patient did not grow in vitro. The carriers for the expanded corneal epithelial cells included corneal stroma, type 1 collagen (Vitrogen), soft contact lenses, collagen shields, and amniotic membrane for the autologous grafts and only amniotic membrane for the allogeneic sibling grafts. Histologic confirmation was reviewed on selected donor grafts. Amniotic membrane as carrier. Further studies were made to determine whether amniotic membrane might be the best carrier for the expanding corneal epithelial cells. Seventeen different combinations of tryspinization, sonication, scraping, and washing were studied to find the simplest, most effective method for removing the amniotic epithelium while still preserving the histologic appearance of the basement membrane of the amnion. Presumed corneal epithelial stem cells were harvested and expanded in vitro and applied to the amniotic membrane to create a composite graft. Thus, the composite graft consisted of the amniotic membrane from which the original epithelium had been removed without significant histologic damage to the basement membrane, and the expanded corneal epithelial stem cells, which had been applied to and had successfully adhered to the denuded amniotic membrane. Animal model. Twelve rabbits had the ocular surface of 1 eye damaged in a standard

  6. The scale of substratum topographic features modulates proliferation of corneal epithelial cells and corneal fibroblasts.

    PubMed

    Liliensiek, S J; Campbell, S; Nealey, P F; Murphy, C J

    2006-10-01

    The cornea is a complex tissue composed of different cell types, including corneal epithelial cells and keratocytes. Each of these cell types are directly exposed to rich nanoscale topography from the basement membrane or surrounding extracellular matrix. Nanoscale topography has been shown to influence cell behaviors, including orientation, alignment, differentiation, migration, and proliferation. We investigated whether proliferation of SV40-transformed human corneal epithelial cells (SV40-HCECs), primary human corneal epithelial cells (HCECs), and primary corneal fibroblasts is influenced by the scale of topographic features of the substratum. Using basement membrane feature sizes as our guide and the known dimensions of collagen fibrils of the corneal stroma (20-60 nm), we fabricated polyurethane molded substrates, which contain anisotropic feature sizes ranging from 200-2000 nm on pitches ranging from 400 to 4000 nm (pitch = ridge width + groove width). The planar regions separating each of the six patterned regions served as control surfaces. Primary corneal and SV40-HCEC proliferation decreased in direct response to decreasing nanoscale topographies down to 200 nm. In contrast to corneal epithelial cells, corneal fibroblasts did not exhibit significantly different response to any of the topographies when compared with planar controls at 5 days. However, decreased proliferation was observed on the smallest feature sizes after 14 days in culture. Results from these experiments are relevant in understanding the potential mechanisms involved in the control of proliferation and differentiation of cells within the cornea.

  7. Relationship among Corneal Biomechanics, Anterior Segment Parameters, and Geometric Corneal Parameters

    PubMed Central

    Çevik, Sadık Görkem; Akova-Budak, Berna; Tok-Çevik, Mediha

    2016-01-01

    Purpose. To investigate the relationship between corneal biomechanical parameters, anterior segment parameters, and geometric corneal parameters in a healthy Caucasian group. Methods. This retrospective study included the healthy eyes with best corrected visual acuity of at least 20/40 of 122 Caucasian subjects. The anterior segment parameters and geometric corneal parameters such as corneal volume, central corneal thickness, horizontal and vertical corneal radii, anterior and posterior steep, and flat keratometric values were measured with a Scheimpflug camera. The biomechanical properties were measured with Ocular Response Analyzer. Results. One hundred and twenty-two healthy Caucasian subjects (67 males, 55 females) with a mean age of 45.32 ± 20.23 were enrolled. Both corneal hysteresis and corneal resistance factor were positively correlated with CCT (r = 0.529, p < 0.001; r = 0.638, p < 0.001) and CV (r = 0.635, p < 0.001; r = 0.579, p < 0.001) and negatively correlated with age (r = −0.373, p < 0.001; r = −0.249, p < 0.001). Both in age-gender and multivariate models, CH and CRF had statistically significant negative association with the posterior steep K value. Conclusions. CH and CRF are negatively correlated with posterior steep and average posterior K values. PMID:27847644

  8. Corneal nerve microstructure in Parkinson's disease.

    PubMed

    Misra, Stuti L; Kersten, Hannah M; Roxburgh, Richard H; Danesh-Meyer, Helen V; McGhee, Charles N J

    2017-03-03

    Ocular surface changes and blink abnormalities are well-established in Parkinson's disease. Blink rate may be influenced by corneal sub-basal nerve density, however, this relationship has not yet been investigated in Parkinson's disease. This case-control study examined the ocular surface in patients with moderately severe Parkinson's disease, including confocal microscopy of the cornea. Fifteen patients with moderately severe Parkinson's disease (modified Hoehn and Yahr grade 3 or 4) and fifteen control participants were recruited. Ophthalmic assessment included slit-lamp examination, blink rate assessment, central corneal aesthesiometry and in vivo corneal confocal microscopy. The effect of disease laterality was also investigated. Of the 15 patients with Parkinson's disease, ten were male and the mean age was 65.5±8.6years. The corneal sub-basal nerve plexus density was markedly reduced in patients with Parkinson's disease (7.56±2.4mm/mm(2)) compared with controls (15.91±2.6mm/mm(2)) (p<0.0001). Corneal sensitivity did not differ significantly between the patients with Parkinson's disease (0.79±1.2mBAR) and the control group (0.26±0.35mBAR), p=0.12. Sub-basal nerve density was not significantly different between the eye ipsilateral to the side of the body with most-severe motor symptoms, and the contralateral eye. There was a significant positive correlation between ACE-R scores and sub-basal corneal nerve density (R(2)=0.66, p=0.02). This is the first study to report a significant reduction in corneal sub-basal nerve density in Parkinson's disease and demonstrate an association with cognitive dysfunction. These results provide further evidence to support the involvement of the peripheral nervous system in Parkinson's disease, previously thought to be a central nervous system disorder.

  9. Cyanoacrylate glue in the treatment of corneal ulcerations.

    PubMed

    Golubović, S; Parunović, A

    1990-01-01

    The application of tissue adhesives to treat different corneal diseases has been used extensively in recent years. Owing to the widespread application, it has been possible to establish the advantages and disadvantages of this method of treatment. Keeping in mind the disadvantages (primarily the toxicity of cyanoacrylate glue for the corneal endothelium and lens when it comes into direct contact with these structures), the application of cyanoacrylate glue was restricted to the treatment of progressive corneal ulcerations where the risk of corneal perforation was recognized. This method of treatment was applied in 30 patients with corneal melting in dry eye associated with rheumatoid arthritis (12), trophic postherpetic ulcerations of the cornea (9), chemical corneal burns (7), neurotrophic corneal ulceration (1) and Mooren's ulcer (1). The defect healed and anterior corneal surface epithelization occurred in 73.33% of patients in contrast to the additional treatment, most commonly penetrating keratoplasty, required in the remaining patients (26.67%).

  10. Changes on the corneal thickness and curvature after orthokeratology

    NASA Astrophysics Data System (ADS)

    Mitsui, Iwane; Yamada, Yoshiya

    2004-07-01

    To evaluate the corneal thickness and curvature changes after Orthokeratology contact lens wear, using the ORBSCAN II corneal topography system, corneal thickness and corneal curvature were measured on one hundred and twenty eyes of sixty patients before and after wearing the custom rigid gas permeable contact lenses for Orthokeratology. The contact lenses were specially designed for each eye. The subjects wore the orthokeratology lenses for approximately Four hours with their eyes closed. The corneal thickness of the subjects was increased on fifty-five eyes at not only the peripheral zone but also the center of the cornea. The average increase of central and peripheral corneal thickness was 18 micrometer and 22micrometer, respectively. The mean anterior curvature of corneal surface changed 1.25D. The mean posterior curvature of corneal endothelium side changed 0.75D.

  11. Genetics Home Reference: lattice corneal dystrophy type I

    MedlinePlus

    ... lattice pattern. Affected individuals often have recurrent corneal erosions, which are caused by separation of particular layers of the cornea from one another. Corneal erosions are very painful and can cause sensitivity to ...

  12. Genetics Home Reference: lattice corneal dystrophy type II

    MedlinePlus

    ... In addition, affected individuals can have recurrent corneal erosions, which are caused by separation of particular layers of the cornea from one another. Corneal erosions are very painful and can cause sensitivity to ...

  13. Surgical strategies to improve visual outcomes in corneal transplantation

    PubMed Central

    Rajan, M S

    2014-01-01

    The recent years have brought about a sea change in the field of corneal transplantation with penetrating keratoplasty being phased to newer lamellar keratoplasty techniques for a variety of corneal pathology. Improved and innovative surgical techniques have allowed selective replacement of diseased host corneal layers with pre-prepared healthy donor corneal lamellae for anterior corneal disorders such as keratoconus and posterior corneal disorders such as Fuch's corneal endothelial dystrophy. The results of lamellar techniques are encouraging, with rapid visual rehabilitation and vastly reduced risk of immune-mediated transplant rejection. The techniques of deep anterior lamellar keratoplasty and Descemet's stripping endothelial keratoplasty (DSAEK) continue to evolve with advent of femtosecond lasers and newer concepts such as pre-conditioned donor corneas for Microthin DSAEK and Descemet's membrane keratoplasty. This review describes the current developments in lamellar keratoplasty, including the futuristic approach using cell therapy to restore vision in corneal blindness. PMID:24384964

  14. The Rabbit Corneal Pocket Assay.

    PubMed

    Morbidelli, Lucia; Ziche, Marina

    2016-01-01

    The rabbit corneal micropocket angiogenesis assay uses the avascular cornea as a substrate canvas to study angiogenesis in vivo. Through the use of standardized slow-release pellets, a predictable angiogenic response is generated over the course of 1-2 weeks and then quantified. Uniform slow-release pellets are prepared by mixing purified angiogenic growth factors such as basic fibroblast growth factor or vascular endothelial growth factor and a synthetic polymer to allow slow release. A micropocket is surgically created in the rabbit cornea under anesthesia and a pellet implanted. On the days later, the angiogenic response is measured and qualified using a slit lamp, as well as the concomitant vascular phenotype or inflammatory features. The results of the assay are used to assess the ability of potential therapeutic molecules to modulate angiogenesis in vivo, both when released locally or given by ocular formulations or through systemic treatment. In this chapter, the experimental details of the rabbit cornea assay and technical implementations to the original protocol are described.

  15. Corneal endothelial autocrine trophic factor VIP in a mechanism-based strategy to enhance human donor cornea preservation for transplantation.

    PubMed

    Koh, Shay-Whey Margaret

    2012-02-01

    Vasoactive intestinal peptide (VIP) and ciliary neurotrophic factor (CNTF) are identified as autocrines of human corneal endothelial (CE) cells working in concert to maintain the differentiated state and promote the survival of the corneal endothelium. From VIP gene knockdown study, endogenous VIP is shown to maintain the level of the differentiation marker, the adhesion molecule N-cadherin, CE cell size, shape, and retention, in situ in the human donor corneoscleral explants. Exogenous VIP protects the corneal endothelium against the killing effect of oxidative stress, in part by upholding ATP levels in CE cells dying of oxidative stress-induced injury, allowing them to die of an apoptotic death instead of an acute necrotic one. The switch from the acute necrosis to the programmed cell death (apoptosis) may have allowed the injured CE cell to be rescued by the VIP-upregulated pathways, including those of Bcl-2 and N-cadherin, and resulted in long-term CE cell survival. The endogenous VIP in CE cells is upregulated by CNTF, which is released by CE cells surviving the oxidative stress. The CNTF receptor (CNTFRα) is expressed in CE cells in human donor corneoscleral explant and gradually becomes lost during corneal storage. VIP treatment (10(-8) M, 37 °C, 30 min) prior to storage of freshly dissected human donor corneoscleral explants increases their CE cell CNTFRα level and responsiveness to CNTF in upregulating the gap junctional protein connexin-43 expression. VIP treatment of both fresh and preserved corneoscleral explants reduces CE damage in the corneoscleral explants and in the corneal buttons trephined from them. CE cell loss is a critical risk factor in corneal graft failure at any time in the life of the graft, which can be as late as 5-10 years after an initially successful transplant. A new procedure, Descemet's stripping automated endothelial keratoplasty (DSAEK), which is superior to the traditional full thickness transplantation in many aspects

  16. Influence of corneal hydration on optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Twa, Michael D.; Vantipalli, Srilatha; Singh, Manmohan; Li, Jiasong; Larin, Kirill V.

    2016-03-01

    Corneal biomechanical properties are influenced by several factors, including intraocular pressure, corneal thickness, and viscoelastic responses. Corneal thickness is directly proportional to tissue hydration and can influence corneal stiffness, but there is no consensus on the magnitude or direction of this effect. We evaluated the influence of corneal hydration on dynamic surface deformation responses using optical coherence elastography (OCE). Fresh rabbit eyes (n=10) were prepared by removing the corneal epithelium and dropping with 0.9% saline every 5 minutes for 1 hour, followed by 20% dextran solution every 5 minutes for one hour. Corneal thickness was determined from structural OCT imaging and OCE measurements were performed at baseline and every 20 minutes thereafter. Micron-scale deformations were induced at the apex of the corneal tissue using a spatially-focused (150μm) short-duration (<1ms) air-pulse delivery system. These dynamic tissue responses were measured non-invasively with a phase-stabilized swept source OCT system. The tissue surface deformation response (Relaxation Rate: RR) was quantified as the time constant, over which stimulated tissue recovered from the maximum deformation amplitude. Elastic wave group velocity (GV) was also quantified and correlated with change in corneal thickness due to hydration process. Corneal thickness rapidly increased and remained constant following epithelium removal and changed little thereafter. Likewise, corneal stiffness changed little over the first hour and then decreased sharply after Dextran application (thickness: -46% [-315/682 μm] RR: - 24% [-0.7/2.88 ms-1]; GV: -19% [-0.6/3.2 m/s]). Corneal thickness and corneal stiffness (RR) were well correlated (R2 = .66). Corneal biomechanical properties are highly correlated with tissue hydration over a wide range of corneal thickness and these changes in corneal stiffness are quantifiable using OCE.

  17. The molecular genetics of the corneal dystrophies--current status.

    PubMed

    Klintworth, Gordon K

    2003-05-01

    The pertinent literature on inherited corneal diseases is reviewed in terms of the chromosomal localization and identification of the responsible genes. Disorders affecting the cornea have been mapped to human chromosome 1 (central crystalline corneal dystrophy, familial subepithelial corneal amyloidosis, early onset Fuchs dystrophy, posterior polymorphous corneal dystrophy), chromosome 4 (Bietti marginal crystalline dystrophy), chromosome 5 (lattice dystrophy types 1 and IIIA, granular corneal dystrophy types 1, 2 and 3, Thiel-Behnke corneal dystrophy), chromosome 9 (lattice dystrophy type II), chromosome 10 (Thiel-Behnke corneal dystrophy), chromosome 12 (Meesmann dystrophy), chromosome 16 (macular corneal dystrophy, fish eye disease, LCAT disease, tyrosinemia type II), chromosome 17 (Meesmann dystrophy, Stocker-Holt dystrophy), chromosome 20 (congenital hereditary endothelial corneal dystrophy types I and II, posterior polymorphous corneal dystrophy), chromosome 21 (autosomal dominant keratoconus) and the X chromosome (cornea verticillata, cornea farinata, deep filiform corneal dystrophy, keratosis follicularis spinulosa decalvans, Lisch corneal dystrophy). Mutations in nine genes (ARSC1, CHST6, COL8A2, GLA, GSN, KRT3, KRT12, M1S1and TGFBI [BIGH3]) account for some of the corneal diseases and three of them are associated with amyloid deposition in the cornea (GSN, M1S1, TGFBI) including most of the lattice corneal dystrophies (LCDs) [LCD types I, IA, II, IIIA, IIIB, IV, V, VI and VII] recognized by their lattice pattern of linear opacities. Genetic studies on inherited diseases affecting the cornea have provided insight into some of these disorders at a basic molecular level and it has become recognized that distinct clinicopathologic phenotypes can result from specific mutations in a particular gene, as well as some different mutations in the same gene. A molecular genetic understanding of inherited corneal diseases is leading to a better appreciation of the

  18. Corneal Collagen Cross-Linking Outcomes: Review

    PubMed Central

    Jankov II, Mirko R; Jovanovic, Vesna; Delevic, Sladjana; Coskunseven, Efekan

    2011-01-01

    Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen cross-linking with riboflavin and UVA (CXL) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. The studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative SEQ was reduced by an average of more than 1 D, and refractive cylinder decreased by about 1 D. No eyes lost any line of BCDVA. Moreover, there was no significant decrease in endothelial cell density. It was also found that CXL treatment was effective with reducing corneal and total wavefront aberrations. Corneal cross-linking has also led to an arrest and/or even a partial reversal of keratectasia in the treatment of iatrogenic ectasia after excimer laser ablation. A primary intervention such as CXL should be considered to potentially increase the biomechanical stability of the corneal tissue and postpone the need of lamellar or penetrating keratoplasty. PMID:21448301

  19. In-vitro corneal transparency measuring system

    NASA Astrophysics Data System (ADS)

    Ventura, Liliane; da Costa Vieira, Marcelo A.; Isaac, Flavio; Chiaradia, Caio; Faria de Sousa, Sidney J.

    2001-06-01

    A system for measuring the average corneal transparency of preserved corneas has been developed in order to provide a more accurate and standard report of the corneal tissue. The donated cornea transparency is one of the features to be analyzed previously to its indication for the transplant. The small portable system consists of two main parts: the optical and the electronic parts. The optical system consists of a white light, lenses and pin-holes that collimate white light beams that illuminates the cornea in its preservative medium. The light that passes through the cornea is detected by a resistive detector and the average corneal transparency is shown in a display. In order to obtain just the tissue transparency, the electronic circuit was built in a way that there is a baseline input of the preservative medium, previous to the measurement of the corneal transparency. Manipulating the system consists of three steps: (1) Adjusting the zero percentage in the absence of light (at this time the detectors in the dark); (2) Placing the preservative medium in the system and adjusting the 100% value (this is the baseline input); (3) Preserving the cornea and placing it in the system. The system provides the tissue transparency. The system is connected to an endothelium evaluation system for Slit Lamp, that we have developed, and statistics about the relationship of the corneal transparency and density of the endothelial cells will be provided in the next years. The system is being used in a public Eye Bank in Brasil.

  20. Corneal Phaeohyphomycosis Caused by Bipolaris hawaiiensis

    PubMed Central

    Chaidaroon, Winai; Supalaset, Sumet; Tananuvat, Napaporn; Vanittanakom, Nongnuch

    2016-01-01

    Purpose To report a rare case of keratitis infected by Bipolaris hawaiiensis. Methods A patient who was diagnosed as fungal keratitis caused by B. hawaiiensis was retrospectively reviewed for history, clinical characteristics, risk factors, laboratory findings, treatments, and outcomes. Results A 63-year-old man with a history of trauma and saw dust in the left eye presented with a corneal ulcer. Eye examination revealed whitish infiltration with a feathery edge and small brownish deposits in the anterior stroma of the left cornea. Numerous septate hyphal fragments were detected in a corneal specimen, and nucleotide sequence analysis identified B. hawaiiensis. Treatment was started with 5% natamycin eyedrops and oral itraconazole. Subsequently, a corneal plaque developed which did not respond to medication and debridement. The patient underwent therapeutic penetrating keratoplasty. Conclusions B. hawaiiensis is a rare cause of corneal phaeohyphomycosis. A brownish pigmented infiltration is an important diagnostic clue, however microbiologic studies are required to obtain a definite diagnosis. Although antifungal medication and debridement are the mainstay of most corneal fungal infection, therapeutic penetrating keratoplasty can prevent morbidity related to this fungal infection. PMID:27721785

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

    PubMed Central

    2013-01-01

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

  2. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  3. Mechanisms of allograft rejection of corneal endothelium

    SciTech Connect

    Tagawa, Y.; Silverstein, A.M.; Prendergast, R.A.

    1982-07-01

    The local intraocular graft-vs.-host (GVH) reaction, involving the destruction of the corneal endothelial cells of the rabbit host by sensitized donor lymphoid cells, has been used to study the mechanism of corneal allograft rejection. Pretreatment of donor cells with a specific mouse monoclonal hybridoma anti-T cell antibody and complement suppresses the destructive reaction, suggesting that a cellular-immune mechanism is primarily involved. Pretreatment of donor cells with mitomycin-C completely abolishes the local GVH reaction, indicating that the effector lymphocytes must undergo mitosis within the eye before they can engage in target cell destruction. Finally, studies of the local GVH reaction in irradiated leukopenic recipients or in preinflamed rabbit eyes suggest that host leukocytes may contribute nonspecifically to enhance the destructive process. These studies show that the local ocular GVH reaction may provide a useful model for the study of the mechanisms involved in the rejection of corneal allografts.

  4. XENOTRANSPLANTATION – THE FUTURE OF CORNEAL TRANSPLANTATION?

    PubMed Central

    Hara, Hidetaka; Cooper, David K.C.

    2010-01-01

    Although corneal transplantation is readily available in the USA and certain other regions of the developed world, the need for human donor corneas worldwide far exceeds supply. There is currently renewed interest in the possibility of using corneas from other species, especially pigs, for transplantation into humans (xenotransplantation). The biomechanical properties of human and pig corneas are similar. Studies in animal models of corneal xenotransplantation have documented both humoral and cellular immune responses that play roles in xenograft rejection. The results obtained from the Tx of corneas from wild-type (i.e., genetically-unmodified) pigs into nonhuman primates have been surprisingly good and encouraging. Recent progress in the genetic manipulation of pigs has led to the prospect that the remaining immunological barriers will be overcome. There is every reason for optimism that corneal xenoTx will become a clinical reality within the next few years. PMID:21099407

  5. Micrometer axial resolution OCT for corneal imaging

    PubMed Central

    Yadav, Rahul; Lee, Kye-Sung; Rolland, Jannick P.; Zavislan, James M.; Aquavella, James V.; Yoon, Geunyoung

    2011-01-01

    An optical coherence tomography (OCT) for high axial resolution corneal imaging is presented. The system uses 375 nm bandwidth (625 to 1000 nm) from a broadband supercontinuum light source. The system was developed in free space to minimize image quality degradation due to dispersion. A custom-designed spectrometer based on a Czerny Turner configuration was implemented to achieve an imaging depth of 1 mm. Experimentally measured axial resolution was 1.1 μm in corneal tissue and had a good agreement with the theoretically calculated resolution from the envelope of the spectral interference fringes. In vivo imaging was carried out and thin corneal layers such as the tear film and the Bowman’s layer were quantified in normal, keratoconus, and contact lens wearing eyes, indicating the system’s suitability for several ophthalmic applications. PMID:22076265

  6. Corneal reepithelialization and anti-inflammatory agents.

    PubMed Central

    Srinivasan, B D

    1982-01-01

    These studies have demonstrated that nonsteroidal anti-inflammatory agents (cyclooxygenase and lipoxygenase inhibitors) can inhibit PMN arrival in the tear fluid following corneal injury but do not inhibit the reepithelialization either by corneal epithelial cells or by conjunctival epithelial cells. Therefore, they can be used safely in ocular inflammatory conditions even when corneal epithelial defects are present. Corticosteroids, on the other hand, inhibit reepithelialization by conjunctival epithelial cells and not by corneal epithelial cells in the doses tested. This inhibition does not occur with pretreatment prior to injury, suggesting that corticosteroids can be used clinically in conditions that have intact corneal epithelium without fear of slowing down wound healing should epithelial defects occur when not on steroid therapy. Furthermore, the steroid inhibition is temporary since there is a breakthrough in steroid inhibition with time, and occurs only if the steroids have been used shortly after deepithelialization. The steroid inhibition can be reversed by specific steroid antagonist, indicating that the steroid effect is mediated through specific receptors. An exciting and new hypothesis proposes that corticosteroids induce the formation of an inhibitory protein that inhibits the phospholipase enzyme to cause a block in arachidonic acid release from cell membranes. This mechanism of action may also be prevalent in the steroid effect on corneal reepithelialization, and experiments are under way to isolate this inhibitory protein from steroid-treated conjunctival epithelium. This isolation and pharmacologic characterization of this inhibitory protein is of obvious advantage to the field of ophthalmic therapeutics since this protein may have the anti-inflammatory potential of the steroids without their steroid sideeffects. Images FIGURE 3 a FIGURE 3 b PMID:6763806

  7. Human pluripotent stem cell-derived limbal epithelial stem cells on bioengineered matrices for corneal reconstruction.

    PubMed

    Mikhailova, Alexandra; Ilmarinen, Tanja; Ratnayake, Anjula; Petrovski, Goran; Uusitalo, Hannu; Skottman, Heli; Rafat, Mehrdad

    2016-05-01

    Corneal epithelium is renewed by limbal epithelial stem cells (LESCs), a type of tissue-specific stem cells located in the limbal palisades of Vogt at the corneo-scleral junction. Acute trauma or inflammatory disorders of the ocular surface can destroy these stem cells, leading to limbal stem cell deficiency (LSCD) - a painful and vision-threatening condition. Treating these disorders is often challenging and complex, especially in bilateral cases with extensive damage. Human pluripotent stem cells (hPSCs) provide new opportunities for corneal reconstruction using cell-based therapy. Here, we investigated the use of hPSC-derived LESC-like cells on bioengineered collagen matrices in serum-free conditions, aiming for clinical applications to reconstruct the corneal epithelium and partially replace the damaged stroma. Differentiation of hPSCs towards LESC-like cells was directed using small-molecule induction followed by maturation in corneal epithelium culture medium. After four to five weeks of culture, differentiated cells were seeded onto bioengineered matrices fabricated as transparent membranes of uniform thickness, using medical-grade porcine collagen type I and a hybrid cross-linking technology. The bioengineered matrices were fully transparent, with high water content and swelling capacity, and parallel lamellar microstructure. Cell proliferation of hPSC-LESCs was significantly higher on bioengineered matrices than on collagen-coated control wells after two weeks of culture, and LESC markers p63 and cytokeratin 15, along with proliferation marker Ki67 were expressed even after 30 days in culture. Overall, hPSC-LESCs retained their capacity to self-renew and proliferate, but were also able to terminally differentiate upon stimulation, as suggested by protein expression of cytokeratins 3 and 12. We propose the use of bioengineered collagen matrices as carriers for the clinically-relevant hPSC-derived LESC-like cells, as a novel tissue engineering approach for

  8. Tissue adhesives: new perspectives in corneal perforations.

    PubMed

    Hirst, L W; Stark, W J; Jensen, A D

    1979-03-01

    In corneal perforations associated with extensive progressive corneal disease, a technique using tissue adhesive closure of the perforation site and reformation of the anterior chamber before penetrating keratoplasty or conjunctival flap mobilization has been described. Over the past year, six eyes have been successfully treated in this manner. This method allows reformation of the eye under local anesthesia as an emergency procedure without incarceration or injury of the intraocular contents and without pain to the patient. The definitive surgical procedure can then be performed safely under retrobulbar anesthesia.

  9. The effect of rigid gas permeable lenses on corneal sensitivity.

    PubMed

    Bergenske, P D; Polse, K A

    1987-03-01

    Long term wear of hard (PMMA) contact lenses decreases corneal sensitivity. Clinicians have noted that in some patients who are refitted with rigid gas permeable (RGP) lenses, there is often an increase in lens awareness. To document this symptom, we monitored changes in corneal sensitivity of long term PMMA wearers who were refitted with RGP lenses. Corneal sensitivity measurements were conducted over a 6-month period. During this time, corneal touch threshold decreased to normal levels within a few weeks after refitting with RGP lenses. These results suggest an oxygen dependency factor in the control of corneal sensitivity accompanying contact lens wear.

  10. Reversible Corneal Toxicity of Retained Intracameral Perfluoro-n-octane

    PubMed Central

    Alharbi, Saad S.; Asiri, Mohammed S.

    2016-01-01

    A 58-year-old female presented with intracameral retained perfluoro-n-octane (PFO) following previous retinal reattachment surgery. After 4 years of follow-up without related sequelae, the patient complained of a gradual decrease in vision secondary to corneal edema with whitish corneal precipitate inferiorly corresponding to the area of retained PFO. Three weeks after anterior chamber washout, corneal edema resolved and the patient obtained 20/40 visual acuity. Even though PFO considered to have a relatively good safety profile, early anterior chamber washout may prevent corneal toxicity and avoid later persistent corneal decompensation. PMID:27555718

  11. 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

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

    PubMed

    Turss, R; Retzlaff, K; Hebrock, R

    1979-02-01

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

  13. Classification of Posterior Polymorphous Corneal Dystrophy as a Corneal Ectatic Disorder Following Confirmation of Associated Significant Corneal Steepening

    PubMed Central

    Aldave, Anthony J.; Ann, Lydia B.; Frausto, Ricardo F.; Nguyen, Catherine K.; Yu, Fei; Raber, Irving M.

    2014-01-01

    Importance Identification of steep corneal curvatures in a significant percentage of patients with posterior polymorphous corneal dystrophy (PPCD) confirms this previously reported association, and suggests a role for ZEB1 in keratocyte function. Objective To determine whether PPCD is characterized by significant corneal steepening. Design Cross-sectional study Setting University-based and private ophthalmology practices Participants Thirty-eight individuals (27 affected and 11 unaffected) from 23 families with PPCD Interventions Slit lamp examination and corneal topographic imaging were performed for individuals with PPCD and unaffected family members. Saliva or blood was collected from each individual for DNA isolation and ZEB1 sequencing. Corneal ZEB1 expression was measured using immunohistochemistry. Main Outcome Measures Percentage of individuals affected with PPCD and controls with average keratometry value >48.0D in each eye; mean keratometry value averaged for both eyes of individuals with PPCD and controls; correlation of ZEB1 mutation with keratometry value Results ZEB1 coding region mutations were identified in 7 of the 27 affected individuals. Ten of the 38 individuals (26.3%) had average keratometry values >48.0D OU: 10/27 (37.0%) individuals with PPCD (6/7 with ZEB1 mutations (85.7%) and 4/20 without ZEB1 mutations (20.0%)) and 0/11 unaffected individuals (p=0.037 for unaffected vs. affected; p=0.004 for PPCD with vs. without ZEB1 mutation). The mean keratometry value of each eye of affected individuals (48.2D) was significantly greater than unaffected family members (44.1D) (p value = 0.029). Affected individuals with ZEB1 mutations demonstrated a mean keratometry value of 53.3D, significantly greater than affected individuals without ZEB1 mutations (46.5D; p value = 0.004). Fluorescence immunohistochemistry demonstrated ZEB1 expression in keratocyte nuclei. Conclusions and Relevance Abnormally steep corneal curvatures are identified in 37% of all

  14. Air assisted lamellar keratectomy for the corneal haze model

    PubMed Central

    Kim, Soohyun; Park, Young Woo; Lee, Euiri; Park, Sang Wan; Park, Sungwon; Kim, Jong Whi; Seong, Je Kyung

    2015-01-01

    To standardize the corneal haze model in the resection depth and size for efficient corneal haze development, air assisted lamellar keratectomy was performed. The ex vivo porcine corneas were categorized into four groups depending on the trephined depth: 250 µm (G1), 375 µm (G2), 500 µm (G3) and 750 µm (G4). The stroma was equally ablated at the five measurement sites in all groups. Significant differences were observed between the trephined corneal depths for resection and ablated corneal thickness in G1 (p < 0.001). No significant differences were observed between the trephined corneal depth for resection and the ablated corneal thickness in G2, G3, and G4. The resection percentage was similar in all groups after microscopic imaging of corneal sections. Air assisted lamellar keratectomy (AK) and conventional keratectomy (CK) method were applied to six beagles, after which development of corneal haze was evaluated weekly until postoperative day 28. The occurrence of corneal haze in the AK group was significantly higher than that in the CK group beginning 14 days after surgery. Alpha-smooth muscle actin expression was significantly higher in the AK group (p < 0.001) than the CK group. Air assisted lamellar keratectomy was used to achieve the desired corneal thickness after resection and produce sufficient corneal haze. PMID:25797296

  15. Novel aspects of corneal angiogenic and lymphangiogenic privilege

    PubMed Central

    Ellenberg, David; Azar, Dimitri T.; Hallak, Joelle A.; Tobaigy, Faisal; Han, Kyu Yeon; Jain, Sandeep; Zhou, Zhongjun; Chang, Jin-Hong

    2013-01-01

    In this article, we provide the results of experimental studies demonstrating that corneal avascularity is an active process involving the production of anti-angiogenic factors, which counterbalance the proangiogenic/lymphangiogenic factors that are upregulated during wound healing. We also summarize pertinent published reports regarding corneal neovascularization (NV), corneal lymphangiogenesis and corneal angiogenic/lymphangiogenic privilege. We outline the clinical causes of corneal NV, and discuss the angiogenic proteins (VEGF and bFGF) and angiogenesis regulatory proteins. We also describe the role of matrix metalloproteinases MMP-2, -7, and MT1-MMP, anti-angiogenic factors, and lymphangiogenic regulatory proteins during corneal wound healing. Established and potential new therapies for the treatment of corneal neovascularization are also discussed. PMID:20100589

  16. Corneal stromal stem cells reduce corneal scarring by mediating neutrophil infiltration after wounding

    PubMed Central

    Funderburgh, Martha L.; Mann, Mary M.; Du, Yiqin

    2017-01-01

    Corneal scarring limits vision for millions of individuals worldwide. Corneal transplantation (keratoplasty) is the standard of care for corneal opacity; however, it bears the risk of graft rejection and infection and is not universally available. Stem cell therapy holds promise as an alternative to keratoplasty. Stem cells from human corneal stroma (CSSC) induce regeneration of transparent corneal tissue in a mouse wound-healing model. In this study we investigated the mechanism by which CSSC prevent deposition of fibrotic tissue. Infiltration by CD11b+/Ly6G+ neutrophils and myeloperoxidase expression were increased in corneas 24 hr after corneal wounding but were reduced in CSSC-treated wounds. Secretion of TSG-6, a protein known to regulate neutrophil migration, was up-regulated in CSSC in response to TNFα and as CSSC differentiate to keratocytes. In vivo, wounded mouse corneas treated with CSSC contained human TSG-6. Inhibition of neutrophil infiltration into cornea by CSSC was reversed when TSG-6 expression was knocked down using siRNA. Silencing of TSG-6 expression in CSSC reduced their ability to block scarring and the expression of mRNA for fibrosis-associated proteins collagen III, tenascin C, and smooth muscle actin in wounded corneas. Neutropenic mice exhibited a significant reduction in corneal scarring and fibrotic mRNA expression 2 weeks after wounding. These results support the conclusion that neutrophil infiltration is an essential event in the fibrotic response to corneal damage and that prevention of scarring by CSSC is mediated by secretion of TSG-6 by these cells. PMID:28257425

  17. Fibrin glue-assisted for the treatment of corneal perforations using glycerin-cryopreserved corneal tissue

    PubMed Central

    Dong, Nuo; Li, Cheng; Chen, Wen-Sheng; Qin, Wen-Juan; Xue, Yu-Hua; Wu, Hu-Ping

    2014-01-01

    AIM To evaluate the outcomes and safety of lamellar keratoplasty (LK) assisted by fibrin glue in corneal perforations. METHODS Six eyes of 6 patients affected by different corneal pathologies (2 posttraumatic corneal scar and 3 bacterial keratitis) underwent LK procedures by using fibrin glue. The mean corneal perforation diameter was 1.35±0.64mm (range, 0.7-2.5mm), and the greatest diameter of the ulcerative stromal defect was 2.47±0.77mm in average (range, 1.5-3.5mm). The donor corneal lamella diameters were 0.20-mm larger and thicker than the recipient to restore a physiologic corneal thickness and shape: mean donor diameter was 8.34±0.28mm (range, 8.2-8.7mm) and mean thickness was 352±40.27mm (range, 220-400mm). Mean follow-up was 7.33±1.97 months (range, 6-11 months). Postoperatively, the graft status, graft clarity, anterior chamber response, the visual prognosis, intraocular pressures, and postoperative complications were recorded. RESULTS All the corneal perforations were successfully healed after the procedure. The best-corrected visual acuity (BCVA) ranged from 20/1 000 to 20/50 in their initial presentation, and from 20/100 to 20/20 in their last visit, showed increase in all the patients. No major complications such as graft dislocation and graft failure were noted. Neovascularization developed in the superficial stroma of donor graft in 1 case. High intraocular pressure developed on day 2 after surgery, while was remained in normal range after application of anti-glaucomatous eyedrops for 1 week in 1 case. CONCLUSION Fibrin glue-assisted sutureless LK is valuable for maintaining the ocular integrity in the treatment of corneal perforations. PMID:24634865

  18. Corneal Higher Order Aberrations in Granular, Lattice and Macular Corneal Dystrophies

    PubMed Central

    Yagi-Yaguchi, Yukari; Yamaguchi, Takefumi; Okuyama, Yumi; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun

    2016-01-01

    Purpose To evaluate the corneal higher-order aberrations (HOAs) in granular, lattice and macular corneal dystrophies. Methods This retrospective study includes consecutive patients who were diagnosed as granular corneal dystrophy type2 (GCD2; 121 eyes), lattice corneal dystrophies type 1, type 3A (LCDI; 20 eyes, LCDIIIA; 32 eyes) and macular corneal dystrophies (MCD; 13 eyes), and 18 healthy control eyes. Corneal HOAs were calculated using anterior segment optical coherence tomography, and the correlations between HOAs and visual acuity were analyzed. Results HOAs of the total cornea within 4 mm diameter were significantly larger in GCD2 (0.17 ± 0.35 μm), in LCDI (0.33 ± 0.27), LCDIIIA (0.61 ± 1.56) and in MCD (0.23 ± 0.18), compared with healthy controls (0.09 ± 0.02μm, all P < 0.01). HOAs of the total cornea within 6 mm diameter were significantly larger in GCD2 (0.32 ± 0.48), in LCDI (0.60 ± 0.46), LCDIIIA (0.83 ± 2.29) and in MCD (0.44 ± 0.24), compared with healthy controls (0.19 ± 0.06, all P < 0.001). In GCD2, there was no significant correlation between logMAR and HOAs (r = 0.113, P = 0.227). In MCD, LCDI and LCDIIIA, logMAR was positively significantly correlated with HOAs (r = 0.620 and P = 0.028, r = 0.587 and P = 0.007, r = 0.614 and P < 0.001, respectively). Conclusions Increased HOAs occur in eyes with corneal dystrophies, especially in eye with LCD and MCD. Larger amount corneal HOAs are associated with poorer visual acuity in patients with LCD and MCD. PMID:27536778

  19. Corneal stromal stem cells reduce corneal scarring by mediating neutrophil infiltration after wounding.

    PubMed

    Hertsenberg, Andrew J; Shojaati, Golnar; Funderburgh, Martha L; Mann, Mary M; Du, Yiqin; Funderburgh, James L

    2017-01-01

    Corneal scarring limits vision for millions of individuals worldwide. Corneal transplantation (keratoplasty) is the standard of care for corneal opacity; however, it bears the risk of graft rejection and infection and is not universally available. Stem cell therapy holds promise as an alternative to keratoplasty. Stem cells from human corneal stroma (CSSC) induce regeneration of transparent corneal tissue in a mouse wound-healing model. In this study we investigated the mechanism by which CSSC prevent deposition of fibrotic tissue. Infiltration by CD11b+/Ly6G+ neutrophils and myeloperoxidase expression were increased in corneas 24 hr after corneal wounding but were reduced in CSSC-treated wounds. Secretion of TSG-6, a protein known to regulate neutrophil migration, was up-regulated in CSSC in response to TNFα and as CSSC differentiate to keratocytes. In vivo, wounded mouse corneas treated with CSSC contained human TSG-6. Inhibition of neutrophil infiltration into cornea by CSSC was reversed when TSG-6 expression was knocked down using siRNA. Silencing of TSG-6 expression in CSSC reduced their ability to block scarring and the expression of mRNA for fibrosis-associated proteins collagen III, tenascin C, and smooth muscle actin in wounded corneas. Neutropenic mice exhibited a significant reduction in corneal scarring and fibrotic mRNA expression 2 weeks after wounding. These results support the conclusion that neutrophil infiltration is an essential event in the fibrotic response to corneal damage and that prevention of scarring by CSSC is mediated by secretion of TSG-6 by these cells.

  20. Stem Cell Therapy for Corneal Regeneration Medicine and Contemporary Nanomedicine for Corneal Disorders.

    PubMed

    Hsu, Chih-Chien; Peng, Chi-Hsien; Hung, Kuo-Hsuan; Lee, Yi-Yen; Lin, Tai-Chi; Jang, Shih-Fan; Liu, Jorn-Hon; Chen, Yan-Ting; Woung, Lin-Chung; Wang, Chien-Ying; Tsa, Ching-Yao; Chiou, Shih-Hwa; Chen, Shih-Jen; Chang, Yuh-Lih

    2015-01-01

    The ocular surface is the outermost part of the visual system that faces many extrinsic or intrinsic threats, such as chemical burn, infectious pathogens, thermal injury, Stevens-Johnson syndrome, ocular pemphegoid, and other autoimmune diseases. The cornea plays an important role in conducting light into the eyes and protecting intraocular structures. Several ocular surface diseases will lead to the neovascularization or conjunctivalization of corneal epithelium, leaving opacified optical media. It is believed that some corneal limbal cells may present stem cell-like properties and are capable of regenerating corneal epithelium. Therefore, cultivation of limbal cells and reconstruction of the ocular surface with these limbal cell grafts have attracted tremendous interest in the past few years. Currently, stem cells are found to potentiate regenerative medicine by their capability of differentiation into multiple lineage cells. Among these, the most common cell sources for clinical use are embryonic, adult, and induced stem cells. Different stem cells have varied specific advantages and limitations for in vivo and in vitro expansion. Other than ocular surface diseases, culture and transplantation of corneal endothelial cells is another major issue for corneal decompensation and awaits further studies to find out comprehensive solutions dealing with nonregenerative corneal endothelium. Recently, studies of in vitro endothelium culture and ρ-associated kinase (ROCK) inhibitor have gained encouraging results. Some clinical trials have already been finished and achieved remarkable vision recovery. Finally, nanotechnology has shown great improvement in ocular drug delivery systems during the past two decades. Strategies to reconstruct the ocular surface could combine with nanoparticles to facilitate wound healing, drug delivery, and even neovascularization inhibition. In this review article, we summarized the major advances of corneal limbal stem cells, limbal stem

  1. Transplacental transfer of cefuroxime in uncomplicated pregnancies and those complicated by hydrops or changes in amniotic fluid volume.

    PubMed Central

    Holt, D E; Fisk, N M; Spencer, J A; de Louvois, J; Hurley, R; Harvey, D

    1993-01-01

    The transplacental transfer of cefuroxime was determined at antenatal fetal blood sampling in a cross sectional study of 78 patients between 15-35 weeks' gestation, 8-138 minutes after a maternal intravenous dose of 750 mg. Mean serum cefuroxime concentration, measured by high performance liquid chromatography, was 7.4 (95% confidence interval (CI) 6.8 to 8.1) mg/l in control fetuses; concentrations in hydropic fetuses were similar (6.2 mg/l, CI 4.7 to 7.7) but in fetuses with oligohydramnios they were significantly lower, (4.9 mg/l, CI 3.6 to 6.2). Antibiotic concentration did not correlate with gestational age and remained unchanged by transfusion of packed red cells. We conclude that (i) fetal serum concentrations of cefuroxime obtained after a maternal dose of 750 mg are only adequate for prophylaxis against organisms with a minimum inhibitory concentration of < 4 mg/l and (ii) transplacental passage of cefuroxime is significantly reduced in the presence of oligohydramnios. PMID:8439202

  2. Potential for Hospital Based Corneal Retreival in Hassan District Hospital

    PubMed Central

    Melsakkare, Suresh Ramappa; Manipur, Sahana R.; Acharya, Pavana; Ramamurthy, Lakshmi Bomalapura

    2015-01-01

    Context In developing countries, corneal diseases are the second leading cause of blindness. This corneal blindness can be treated through corneal transplantation. Though the present infrastructure is strong enough to increase keratoplasty numbers at a required rate, India has largest corneal blind population in the world. So a constant supply of high quality donor corneal tissue is the key factor for reduction of prevalence of corneal blindness. Considering the magnitude of corneal blindness and shortage of donor cornea, there is a huge gap in the demand and supply. Aim To study the potential for hospital based retrieval of donor corneal tissue in Hassan district hospital after analysing the indicated and contraindicated causes of deaths, so that hospital corneal retrieval program in Hassan district hospital can be planned. Materials and Methods The cross-sectional, retrospective and record-based study included all hospital deaths with age group more than two years occurred during one year period (January 2014 to December 2014). Data regarding demographic profile, cause of death, treatment given and presence of any systemic diseases were collected. The causes of deaths which are contraindicated for the retrieval of corneas were analysed and noted. The contraindications were based on the NPCB guidelines for standard of eye banking in India 2009. Results Out of 855 deaths, number of deaths in males (565) was greater than females (290). Numbers of deaths were highest between 41-60 years age group (343). Deaths due to HIV, septicaemia, meningitis, encephalitis, disseminated malignancies were contraindicated for corneal retrieval. Corneas could be retrieved from 736 deaths out of 855. Potential for corneal retrieval in a period of one year in Hassan District hospital was 86%. Conclusion Hospital corneal retrieval program has got a great potential to bridge the gap between the need for the cornea and actually collected corneas which will contribute enormously in

  3. A brief history of corneal transplantation: From ancient to modern.

    PubMed

    Crawford, Alexandra Z; Patel, Dipika V; McGhee, Charles Nj

    2013-09-01

    This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD). Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17(th) and 18(th) centuries, true scientific and surgical experimentation in this field did not begin until the 19(th) century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term "keratoplasty". Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838-unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of corticosteroids. Recent

  4. A brief history of corneal transplantation: From ancient to modern

    PubMed Central

    Crawford, Alexandra Z; Patel, Dipika V; McGhee, Charles NJ

    2013-01-01

    This review highlights many of the fundamental concepts and events in the development of corneal transplantation – from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD). Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17th and 18th centuries, true scientific and surgical experimentation in this field did not begin until the 19th century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term “keratoplasty”. Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838—unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of corticosteroids. Recent

  5. Comparative study of corneal tangent elastic modulus measurement using corneal indentation device.

    PubMed

    Ko, Match W L; Leung, Leo K K; Lam, David C C

    2014-09-01

    The aim of this study is to examine the corneal tangent modulus measurement repeatability and performance of the corneal indentation device (CID). Twenty enucleated porcine eyes were measured and the eyes were pressurized using saline solution-filled manometer to 15 and 30 mmHg. Corneal tangent moduli measured using the CID were compared with those measured using high precision universal testing machine (UTM). The within-subject standard deviation (Sw), repeatability (2.77×Sw), coefficient of variation (CV) (Sw/overall mean), and intraclass correlation coefficient (ICC) were determined. The mean corneal tangent moduli measured using UTM and CID were 0.094±0.030 and 0.094±0.028 MPa at 15 mmHg, and 0.207±0.056 and 0.207±0.055 MPa at 30 mmHg, respectively, with a difference less than 0.13%. The 95% limit of agreement was between -0.009 and 0.009 MPa. The Sw, repeatability, CV and ICC of corneal tangent moduli measured by the CID were 0.006 MPa, 0.015 MPa, 4.3% and 0.993, respectively. The results showed that the corneal tangent moduli measured by the CID are repeatable and are in good agreement with the results measured by the high precision UTM.

  6. Corneal collagen cross-linking: a review.

    PubMed

    O'Brart, David P S

    2014-01-01

    The aim was to review the published literature on corneal collagen cross-linking. The emphasis was on the seminal publications, systemic reviews, meta-analyses and randomized controlled trials. Where such an evidence did not exist, selective large series cohort studies, case controlled studies and case series with follow-up preferably greater than 12 months were included. Riboflavin/Ultraviolet A (UVA) corneal collagen cross-linking appears to be the first treatment modality to halt the progression of keratoconus and other corneal ectatic disorders with improvement in visual, keratometric and topographic parameters documented by most investigators. Its precise mechanism of action at a molecular level is as yet not fully determined. Follow-up is limited to 4-6 years at present but suggests continued stability and improvement in corneal shape with time. Most published data are with epithelium-off techniques. Epithelium-on studies suggest some efficacy but less than with the epithelium-off procedures and long-term data are not currently available. The use of Riboflavin/UVA CXL for the management of infectious and non-infectious keratitis appears very promising. Its use in the management of bullous keratopathy is equivocal. Investigation of other methodologies for CXL are under investigation.

  7. Corneal topography measurements for biometric applications

    NASA Astrophysics Data System (ADS)

    Lewis, Nathan D.

    The term biometrics is used to describe the process of analyzing biological and behavioral traits that are unique to an individual in order to confirm or determine his or her identity. Many biometric modalities are currently being researched and implemented including, fingerprints, hand and facial geometry, iris recognition, vein structure recognition, gait, voice recognition, etc... This project explores the possibility of using corneal topography measurements as a trait for biometric identification. Two new corneal topographers were developed for this study. The first was designed to function as an operator-free device that will allow a user to approach the device and have his or her corneal topography measured. Human subject topography data were collected with this device and compared to measurements made with the commercially available Keratron Piccolo topographer (Optikon, Rome, Italy). A third topographer that departs from the standard Placido disk technology allows for arbitrary pattern illumination through the use of LCD monitors. This topographer was built and tested to be used in future research studies. Topography data was collected from 59 subjects and modeled using Zernike polynomials, which provide for a simple method of compressing topography data and comparing one topographical measurement with a database for biometric identification. The data were analyzed to determine the biometric error rates associated with corneal topography measurements. Reasonably accurate results, between three to eight percent simultaneous false match and false non-match rates, were achieved.

  8. [Purulent corneal ulcers: etiology, pathogenesis, classification].

    PubMed

    Kasparova, Evg A

    2015-01-01

    Advanced purulent corneal ulcer, as well as abscess, is a serious vision-threatening condition notable for its fulminant course and possible loss of the eye due to endophthalmitis. Its leading causes, pathogenesis, and classifications are described and analyzed in this paper.

  9. Peptide Amphiphiles in Corneal Tissue Engineering

    PubMed Central

    Miotto, Martina; Gouveia, Ricardo M.; Connon, Che J.

    2015-01-01

    The increasing interest in effort towards creating alternative therapies have led to exciting breakthroughs in the attempt to bio-fabricate and engineer live tissues. This has been particularly evident in the development of new approaches applied to reconstruct corneal tissue. The need for tissue-engineered corneas is largely a response to the shortage of donor tissue and the lack of suitable alternative biological scaffolds preventing the treatment of millions of blind people worldwide. This review is focused on recent developments in corneal tissue engineering, specifically on the use of self-assembling peptide amphiphiles for this purpose. Recently, peptide amphiphiles have generated great interest as therapeutic molecules, both in vitro and in vivo. Here we introduce this rapidly developing field, and examine innovative applications of peptide amphiphiles to create natural bio-prosthetic corneal tissue in vitro. The advantages of peptide amphiphiles over other biomaterials, namely their wide range of functions and applications, versatility, and transferability are also discussed to better understand how these fascinating molecules can help solve current challenges in corneal regeneration. PMID:26258796

  10. Corneal collagen cross-linking: A review

    PubMed Central

    O’Brart, David P.S.

    2014-01-01

    The aim was to review the published literature on corneal collagen cross-linking. The emphasis was on the seminal publications, systemic reviews, meta-analyses and randomized controlled trials. Where such an evidence did not exist, selective large series cohort studies, case controlled studies and case series with follow-up preferably greater than 12 months were included. Riboflavin/Ultraviolet A (UVA) corneal collagen cross-linking appears to be the first treatment modality to halt the progression of keratoconus and other corneal ectatic disorders with improvement in visual, keratometric and topographic parameters documented by most investigators. Its precise mechanism of action at a molecular level is as yet not fully determined. Follow-up is limited to 4–6 years at present but suggests continued stability and improvement in corneal shape with time. Most published data are with epithelium-off techniques. Epithelium-on studies suggest some efficacy but less than with the epithelium-off procedures and long-term data are not currently available. The use of Riboflavin/UVA CXL for the management of infectious and non-infectious keratitis appears very promising. Its use in the management of bullous keratopathy is equivocal. Investigation of other methodologies for CXL are under investigation. PMID:25000866

  11. Aspergillus terreus recovered from a corneal scraping.

    PubMed

    Campbell, Suzanne

    2014-01-01

    A 52 year old, healthy male presented to his optometrist complaining of redness and irritation in the right eye. A foreign body was removed from the eye. The patient was started on ophthalmic solutions of vigamox and systane. At 48 hours, the patient reported increased redness, limited vision, and yellow discharge from the eye. The patient was referred to an ophthalmologist for further evaluation. Physical assessment revealed a superlative central infiltrate (extreme, centrally located injury that had permeated the cornea), diffuse corneal haze, and edema with a 3- to 4+ conjunctival injection and a 1 millimeter hypopyon (an effusion of pus into the anterior chamber of the eye). Corneal scrapings were collected for aerobic and anaerobic bacterial and fungal cultures. The patient was then prescribed. vancomycin, tobramycin, and natamycin ophthalmic eyedrops. On day three, fungal culture results indicated possible fungal forms seen. On day 12, results from the fungal culture of the corneal scraping revealed the causative agent to be Aspergillus terreus. Voriconazole eyedrops were added to the treatment regimen and continued for 10 weeks. The physician order for a fungal culture as well as laboratory data providing the final identification of Aspergillus terreus and laboratory comments indicating an elevated minimum inhibitory concentration (MIC) (> 2 microg/mL) to amphotericin B is associated with treatment failure positively impacted the patient outcome. After completion of the treatment regimen, a photo-therapeutic keratectomy (PTK) was performed in an attempt to remove the dense corneal scarring caused by the fungal infection.

  12. Mycobacterium chelonei infection of a corneal graft.

    PubMed Central

    Aylward, G. W.; Stacey, A. R.; Marsh, R. J.

    1987-01-01

    We present a case of Mycobacterium chelonei infection in a corneal graft. The chronic ulceration and stromal infiltration followed a well defined course and eventually responded to topical amikacin, though a further graft was required. Previous cases of keratitis due to the M. fortuitum complex are reviewed. Images PMID:3311141

  13. Vitamin D Enhances Corneal Epithelial Barrier Function

    PubMed Central

    Yin, Zhaohong; Pintea, Victorina; Lin, Yanping; Hammock, Bruce D.

    2011-01-01

    Purpose. The purpose of this study was to determine whether 25-hydroxyvitamin D3 (25(OH)D3) and/or its active metabolite, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), can enhance corneal epithelial barrier function. The authors also determined if corneas contain mRNA for the vitamin D receptor (VDR) and 1α-hydroxylase, the enzyme required to convert 25(OH)D3 to 1,25(OH)2D3, and measured vitamin D metabolite concentrations in aqueous and vitreous humor. Methods. RT-PCR was used to examine mouse, rabbit, and human corneal epithelial VDR and 1α-hydroxylase mRNA. Vitamin D metabolites were measured using a selective vitamin D derivatizing agent and mass spectroscopy. Barrier function experiments were performed by measuring inulin permeability (IP) and/or transepithelial resistance (TER) in control, 25(OH)D3-, and 1,25(OH)2D3-treated human and rabbit corneal epithelial monolayers cultured on permeable inserts. Ca2+ was removed, then reintroduced to the culture medium while IP and TER readings were taken. Occludin levels were examined using Western blotting. Results. All corneal samples were positive for both VDR and 1α-hydroxylase mRNA. All vitamin D metabolites except for unhydroxylated vitamin D3 were detected in aqueous and vitreous humor. Epithelial cells showed increased TER, decreased IP, and increased occludin levels when cultured with 25(OH)D3 and 1,25(OH)2D3. Conclusions. We conclude that corneas contain mRNA for VDR and 1α-hydroxylase as well as significant vitamin D concentrations. 25(OH)D3 and its active metabolite 1,25(OH)2D3, both enhance corneal epithelial barrier function. PMID:21715350

  14. Unilateral corneal leukoplakia without limbal involvement

    PubMed Central

    Hirano, Koji; Koide, Mihoko; Mizoguchi, Yoshikazu; Osakabe, Yasuhiro; Sasaki, Kaoru-Araki

    2015-01-01

    Purpose Leukoplakia is the term given to a white patch or plaque that is found mainly on the oral mucus membrane. It can occasionally be seen on the corneal surface. We report our clinical and histopathological findings in a case of unilateral corneal leukoplakia. Methods A 26-year-old woman was referred to our hospital because of a white patch on her right cornea that continued to expand. She first noticed the white patch when she was 20 years old, and the white patch had expanded to cover the pupillary area affecting her vision. After plastic surgery on both eyelids for bilateral entropion to alleviate the pain caused by the eyelashes rubbing the cornea, the white corneal patch decreased in size. Because of this reduction, we performed surgery to remove the patch with microforceps under topical anesthesia. The plaque was removed easily and completely, and submitted for histopathological examination. Results Histopathological examination showed that the specimen had characteristics of epidermis with a basal cell layer, spinous cell layer, granular cell layer, and horny layer with hyperkeratosis. She was diagnosed with leukoplakia of the corneal surface. The basic structure of the squamous cell layer was preserved, and there were no signs of metaplasia. Six months after the removal of the leukoplakia, no recurrence was seen and her corrected decimal visual acuity recovered to 1.0. Conclusion Our case of unilateral corneal leukoplakia without limbal involvement was most likely caused by chronic irritation of the cornea by the eyelashes. Although it was totally removed with good recovery of vision, we continue to follow the patient because of the potential of malignant transformation. PMID:26056494

  15. Oxygen-deficient metabolism and corneal edema.

    PubMed

    Leung, B K; Bonanno, J A; Radke, C J

    2011-11-01

    Wear of low-oxygen-transmissible soft contact lenses swells the cornea significantly, even during open eye. Although oxygen-deficient corneal edema is well-documented, a self-consistent quantitative prediction based on the underlying metabolic reactions is not available. We present a biochemical description of the human cornea that quantifies hypoxic swelling through the coupled transport of water, salt, and respiratory metabolites. Aerobic and anaerobic consumption of glucose, as well as acidosis and pH buffering, are incorporated in a seven-layer corneal model (anterior chamber, endothelium, stroma, epithelium, postlens tear film, contact lens, and prelens tear film). Corneal swelling is predicted from coupled transport of water, dissolved salts, and especially metabolites, along with membrane-transport resistances at the endothelium and epithelium. At the endothelium, the Na+/K+ - ATPase electrogenic channel actively transports bicarbonate ion from the stroma into the anterior chamber. As captured by the Kedem-Katchalsky membrane-transport formalism, the active bicarbonate-ion flux provides the driving force for corneal fluid pump-out needed to match the leak-in tendency of the stroma. Increased lactate-ion production during hypoxia osmotically lowers the pump-out rate requiring the stroma to swell to higher water content. Concentration profiles are predicted for glucose, water, oxygen, carbon dioxide, and hydronium, lactate, bicarbonate, sodium, and chloride ions, along with electrostatic potential and pressure profiles. Although the active bicarbonate-ion pump at the endothelium drives bicarbonate into the aqueous humor, we find a net flux of bicarbonate ion into the cornea that safeguards against acidosis. For the first time, we predict corneal swelling upon soft-contact-lens wear from fundamental biophysico-chemical principles. We also successfully predict that hypertonic tear alleviates contact-lens-induced edema.

  16. Oxygen-deficient metabolism and corneal edema

    PubMed Central

    Leung, B.K.; Bonanno, J.A.; Radke, C.J.

    2014-01-01

    Wear of low-oxygen-transmissible soft contact lenses swells the cornea significantly, even during open eye. Although oxygen-deficient corneal edema is well-documented, a self-consistent quantitative prediction based on the underlying metabolic reactions is not available. We present a biochemical description of the human cornea that quantifies hypoxic swelling through the coupled transport of water, salt, and respiratory metabolites. Aerobic and anaerobic consumption of glucose, as well as acidosis and pH buffering, are incorporated in a seven-layer corneal model (anterior chamber, endothelium, stroma, epithelium, postlens tear film, contact lens, and prelens tear film). Corneal swelling is predicted from coupled transport of water, dissolved salts, and especially metabolites, along with membrane-transport resistances at the endothelium and epithelium. At the endothelium, the Na+/K+ - ATPase electrogenic channel actively transports bicarbonate ion from the stroma into the anterior chamber. As captured by the Kedem–Katchalsky membrane-transport formalism, the active bicarbonate-ion flux provides the driving force for corneal fluid pump-out needed to match the leak-in tendency of the stroma. Increased lactate-ion production during hypoxia osmotically lowers the pump-out rate requiring the stroma to swell to higher water content. Concentration profiles are predicted for glucose, water, oxygen, carbon dioxide, and hydronium, lactate, bicarbonate, sodium, and chloride ions, along with electrostatic potential and pressure profiles. Although the active bicarbonate-ion pump at the endothelium drives bicarbonate into the aqueous humor, we find a net flux of bicarbonate ion into the cornea that safeguards against acidosis. For the first time, we predict corneal swelling upon soft-contact-lens wear from fundamental biophysico-chemical principles. We also successfully predict that hypertonic tear alleviates contact-lens-induced edema. PMID:21820076

  17. Review: Corneal epithelial stem cells, their niche and wound healing

    PubMed Central

    2013-01-01

    Stem cells emerged as a concept during the second half of 19th century, first as a theoretical entity, but then became one of the most promising research fields in cell biology. This work describes the most important characteristics of adult stem cells, including the experimental criteria used to identify them, and discusses current knowledge that led to the proposal that stem cells existed in different parts of the eye, such as the retina, lens, conjunctiva, corneal stroma, Descemet’s membrane, and the subject of this review: the corneal epithelium. Evidence includes results that support the presence of corneal epithelial stem cells at the limbus, as well as the major obstacles to isolating them as pure cell populations. Part of this review describes the variation in the basement membrane composition between the limbus and the central cornea, to show the importance of the corneal stem cell niche, its structure, and the participation of extracellular matrix (ECM) components in regulating corneal stem cell compartment. Results obtained by various laboratories suggest that the extracellular matrix plays a central role in regulating stem cell commitment, corneal differentiation, and participation in corneal wound healing, in addition to other environmental signals such as cytokines and growth factors. The niche could define cell division patterns in corneal stem cell populations, establishing whether stem cells divide asymmetrically or symmetrically. Characterization and understanding of the factors that regulate corneal epithelial stem cells should open up new paths for developing new therapies and strategies for accelerating and improving corneal wound healing. PMID:23901244

  18. Anatomical characterization of central, apical and minimal corneal thickness

    PubMed Central

    Saenz-Frances, Federico; Bermúdez-Vallecilla, Martha Cecilia; Borrego-Sanz, Lara; Jañez, Luis; Martinez-de-la-Casa, José María; Morales-Fernandez, Laura; Santos-Bueso, Enrique; Garcia-Sanchez, Julián; Garcia-Feijoo, Julián

    2014-01-01

    AIM To anatomically locate the points of minimum corneal thickness and central corneal thickness (pupil center) in relation to the corneal apex. METHODS Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex (AT), minimum corneal thickness (MT) and corneal thickness at the pupil center (PT) were determined using the pentacam. Distances from the corneal apex to MT (MD) and PT (PD) were calculated and their quadrant position (taking the corneal apex as the reference) determined: point of minimum thickness (MC) and point of central thickness (PC) depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume (determined using the Pentacam) and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models. RESULTS MT was located at a mean distance of 0.909 mm from the apex (79.4% in the inferior-temporal quadrant). PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume (B=-0.024; 95%CI: -0.043 to -0.004). No significant relations were identified in the linear regression model for PD or the multinomial logistic regressions for MC and PC. CONCLUSION MT was typically located at the inferior-temporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume. PMID:25161940

  19. Interferometer for measuring dynamic corneal topography

    NASA Astrophysics Data System (ADS)

    Micali, Jason Daniel

    The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. It is desirable to possess an instrument that can measure the corneal shape and tear film surface with the same accuracy and resolution that is currently performed on common optical elements. A dual interferometer system for measuring the dynamic corneal topography is designed, built, and verified. The completed system is validated by testing on human subjects. The system consists of two co-aligned polarization splitting Twyman-Green interferometers designed to measure phase instantaneously. The primary interferometer measures the surface of the tear film while the secondary interferometer simultaneously tracks the absolute position of the cornea. Eye motion, ocular variation, and a dynamic tear film surface will result in a non-null configuration of the surface with respect to the interferometer system. A non-null test results in significant interferometer induced errors that add to the measured phase. New algorithms are developed to recover the absolute surface topography of the tear film and corneal surface from the simultaneous interferometer measurements. The results are high-resolution and high-accuracy surface topography measurements of the in vivo cornea that are captured at standard camera frame rates. This dissertation will cover the development and construction of an interferometer system for measuring the dynamic corneal topography of the human eye. The discussion starts with the completion of an interferometer for measuring the tear film. The tear film interferometer is part of an

  20. Systemic Immunomodulatory Strategies in High-risk Corneal Transplantation

    PubMed Central

    Abud, Tulio B.; Di Zazzo, Antonio; Kheirkhah, Ahmad; Dana, Reza

    2017-01-01

    The cornea is the most commonly transplanted tissue in the body. Although corneal grafts generally have high success rates, transplantation onto inflamed and vascularized host beds, or so-called high-risk corneal transplantation, has a high rate of graft rejection. The management of this high-risk corneal transplantation is challenging and involves numerous measures. One of the key measures to prevent graft rejection in these cases is the use of systemic immunosuppressive agents. In this article, we will review the systemic immunosuppressive agents most commonly used for high-risk corneal transplantation, which include corticosteroids, cysclosporine A, tacrolimus, mycophenolate mofetil, and rapamycin. Benefits, risks, and published data on the use of these medications for high-risk corneal transplantation will be detailed. We will also summarize novel immunoregulatory approaches that may be used to prevent graft rejection in high-risk corneal transplantation. PMID:28299010

  1. Systemic Immunomodulatory Strategies in High-risk Corneal Transplantation.

    PubMed

    Abud, Tulio B; Di Zazzo, Antonio; Kheirkhah, Ahmad; Dana, Reza

    2017-01-01

    The cornea is the most commonly transplanted tissue in the body. Although corneal grafts generally have high success rates, transplantation onto inflamed and vascularized host beds, or so-called high-risk corneal transplantation, has a high rate of graft rejection. The management of this high-risk corneal transplantation is challenging and involves numerous measures. One of the key measures to prevent graft rejection in these cases is the use of systemic immunosuppressive agents. In this article, we will review the systemic immunosuppressive agents most commonly used for high-risk corneal transplantation, which include corticosteroids, cysclosporine A, tacrolimus, mycophenolate mofetil, and rapamycin. Benefits, risks, and published data on the use of these medications for high-risk corneal transplantation will be detailed. We will also summarize novel immunoregulatory approaches that may be used to prevent graft rejection in high-risk corneal transplantation.

  2. Using genipin-crosslinked acellular porcine corneal stroma for cosmetic corneal lens implants.

    PubMed

    Liu, Zhao; Zhou, Qiang; Zhu, Jixiang; Xiao, Jianhui; Wan, Pengxia; Zhou, Chenjing; Huang, Zheqian; Qiang, Na; Zhang, Wei; Wu, Zheng; Quan, Daping; Wang, Zhichong

    2012-10-01

    Acellular porcine corneal stroma (APCS) has been proven to maintain the matrix microenvironment and is therefore an ideal biomaterial for the repair and reconstruction of corneal stroma. This study aims to develop a method to prepare cosmetic corneal lens implants for leukoma using genipin-crosslinked APCS (Gc-APCS). The Gc-APCS was prepared from APCS immersed in 1.0% genipin aqueous solution (pH 5.5) for 4 h at 37 °C, followed by lyophilization at -10 °C. The color of the Gc-APCS gradually deepened to dark-blue. The degree of crosslinking was 45.7 ± 4.6%, measured by the decrease of basic and hydroxy amino acids. The porous structure and ultrastructure of collagenous lamellae were maintained, and the porosity and BET SSA were 72.7 ± 4.6% and 23.01 ± 3.45 m(2)/g, respectively. The Gc-APCS rehydrated to the physiological water content within 5 min and was highly resistant to collagenase digestion. There were no significant differences in the areal modulus and curvature variation between Gc-APCS and nature porcine cornea. The dark-blue pigments were stable to pH, light and implantation in vivo. Gc-APCS extracts had no inhibitory effects on the proliferation of keratocytes. Corneal neovascularization, graft degradation and corneal rejection were not observed within 6 months.

  3. Analysis of correlation between corneal topographical data and visual performance

    NASA Astrophysics Data System (ADS)

    Zhou, Chuanqing; Yu, Lei; Ren, Qiushi

    2007-02-01

    Purpose: To study correlation among corneal asphericity, higher-order aberrations and visual performance for eyes of virgin myopia and postoperative laser in situ keratomileusis (LASIK). Methods: There were 320 candidates 590 eyes for LASIK treatment included in this study. The mean preoperative spherical equivalence was -4.35+/-1.51D (-1.25 to -9.75), with astigmatism less than 2.5 D. Corneal topography maps and contrast sensitivity were measured and analyzed for every eye before and one year after LASIK for the analysis of corneal asphericity and wavefront aberrations. Results: Preoperatively, only 4th and 6th order aberration had significant correlation with corneal asphericity and apical radius of curvature (p<0.001). Postoperatively, all 3th to 6th order aberrations had statistically significant correlation with corneal asphericity (p<0.01), but only 4th and 6th order aberration had significant correlation with apical radius of curvature (p<0.05). The asymmetrical aberration like coma had significant correlation with vertical offset of pupil center (p<0.01). Preoperatively, corneal aberrations had no significant correlation with visual acuity and area under the log contrast sensitivity (AULCSF) (P>0.05). Postoperatively, corneal aberrations still didn't have significant correlation with visual acuity (P>0.05), but had significantly negative correlation with AULCSF (P<0.01). Corneal asphericity had no significant correlation with AULCSF before and after the treatment (P>0.05). Conclusions: Corneal aberrations had different correlation with corneal profile and visual performance for eyes of virgin myopia and postoperative LASIK, which may be due to changed corneal profile and limitation of metrics of corneal aberrations.

  4. Retinal evaluation and treatment after refractive corneal surgery.

    PubMed

    Swinger, C A; Kraushar, M F

    1985-08-01

    Refractive corneal surgery (a collective term used to describe a variety of surgical procedures that alter the refractive status of the eye through the surgical modification of corneal curvature) shows promise for use in situations where current methods of optical correction do not meet the patient's needs. This article reviews our experiences with the retinal evaluation of patients who have undergone corneal refractive surgery and offers recommendations for the treatment of retinal pathology after such surgery.

  5. Detection of ectatic corneal diseases based on pentacam.

    PubMed

    Lopes, Bernardo T; Ramos, Isaac C; Dawson, Daniel G; Belin, Michael W; Ambrósio, Renato

    2016-06-01

    Pentacam is a rotating Scheimpflug-based corneal and anterior segment tomographer that gives as comprehensive analysis of corneal 3D geometry. With this device the detection of mild keratoconus or ectasia susceptibility is possible. This is fundamental for screening ectasia risk prior to laser vision correction. The identification of susceptible cases at risk for developing progressive iatrogenic ectasia should go beyond (but not over) corneal front surface topography.

  6. New null screen design for corneal topography

    NASA Astrophysics Data System (ADS)

    Campos-García, Manuel; Estrada-Molina, Amilcar; Díaz-Uribe, Rufino

    2011-09-01

    In this work we report the design of a null screen for corneal topography. Here we assume that the corneal surface is an ellipsoid with a diameter of 12 mm and a curvature radius of 7.8 mm. To avoid the difficulties in the alignment of the test system due to the face contour (eyebrows, nose, or eyelids), we design a conical null-screen with spots (similar to ellipses) drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact radial array of circular spots if the surface is perfect. Additionally, we performed a numerical simulation introducing Gaussian random errors in the coordinates of the centroids of the spots on the image plane, and in the coordinates of the sources (spots on the null-screen) in order to obtain the conical null-screen that reduces the error in the evaluation of the topography.

  7. Automatic analysis of the corneal ulcer

    NASA Astrophysics Data System (ADS)

    Ventura, Liliane; Chiaradia, Caio; Faria de Sousa, Sidney J.

    1999-06-01

    A very common disease in agricultural countries is the corneal ulcer. Particularly in the public hospitals, several patients come every week presenting this kind of pathology. One of the most important features to diagnose the regression of the disease is the determination of the vanishing of the affected area. An automatic system (optical system and software), attached to a Slit Lamp, has been developed to determine automatically the area of the ulcer and to follow up its regression. The clinical procedure to isolate the ulcer is still done, but the measuring time is fast enough to not cause discomfort to the patient as the traditional evaluation does. The system has been used in the last 6 months in a hospital that has about 80 patients per week presenting corneal ulcer. The patients follow up (which is an indispensable criteria for the cure of the disease) has been improved by the system and has guaranteed the treatment success.

  8. Corneal cross-linking treatment of keratoconus

    PubMed Central

    Farjadnia, Mahgol; Naderan, Mohammad

    2015-01-01

    Keratoconus as the most common cause of ectasia is one of the leading cause of corneal transplants worldwide. The current available therapies do not modify the underlying pathogenesis of the disease, and none of the available approaches but corneal transplant hinder the ongoing ectasia. Several studies document Crosslink defect between collagen fibrils in the pathogenesis of keratoconus. Collagen cross link is a relatively new approach that with the application of the riboflavin and ultraviolet A, new covalent bands reform. Subjective and objective results following this method seem to be promising. Endothelial damage besides other deep structural injury, which is the major concern of this technique have not yet been reported, when applying the standard method. PMID:26622134

  9. Strategies for developing decellularized corneal scaffolds.

    PubMed

    Lynch, Amy P; Ahearne, Mark

    2013-03-01

    The main obstacle to successfully engineering corneal tissue has been the replication of the structural and biochemical composition of native cornea in a scaffold. In recent years decellularized corneas have been under investigation as an alternative scaffold source for use in engineering cornea. Several strategies for lysing cells and removing cellular material from corneas are discussed. The removal of such cellular components and antigen molecules whilst maintaining the corneal extracellular matrix components and architecture is required to generate scaffolds capable of generating functional tissue grafts suitable for transplantation. Different techniques to ascertain the degree of decellularization and the change in structural, mechanical and biological characteristics of the corneas after treatment are examined. In addition several in vitro and in vivo studies have been performed to ascertain the suitability of decellularized corneas as a scaffold for restoring vision.

  10. Human excimer laser corneal surgery: preliminary report.

    PubMed Central

    L'Esperance, F A; Taylor, D M; Del Pero, R A; Roberts, A; Gigstad, J; Stokes, M T; Warner, J W; Telfair, W B; Martin, C A; Yoder, P R

    1988-01-01

    The first human trial utilizing the argon fluoride excimer laser at 193 nm to produce a superficial keratectomy in ten human eyes has been described with the histopathological evaluation of four eyes and the longer gross appearance of six eyes at intervals extending to 10 months post-excimer laser treatment. The process of laser superficial keratectomy has proved to be one of the promising areas of surgical intervention for reconstructive or refractive keratoplasty in the future. Intensive investigations need to be undertaken on the corneal wound healing process following laser ablation as well as the nature, and long-term stability of the corneal excisions or induced refractive corrections. It is essential that the optimal laser parameters be established for the various refractive corrections and other corneal surgical techniques, and that pathophysiologic and histopathologic changes that have been induced by the excimer laser-corneal tissue interaction in animals and humans be critically and extensively analyzed. Images FIGURE 1 FIGURE 19 A FIGURE 19 B FIGURE 20 A FIGURE 20 B FIGURE 21 A FIGURE 21 B FIGURE 22 A FIGURE 22 B FIGURE 23 FIGURE 24 FIGURE 25 FIGURE 26 FIGURE 27 FIGURE 28 FIGURE 29 A FIGURE 29 B FIGURE 29 C FIGURE 29 D FIGURE 30 A FIGURE 30 B FIGURE 31 A FIGURE 31 B FIGURE 32 FIGURE 33 FIGURE 34 FIGURE 35 FIGURE 36 FIGURE 37 A FIGURE 37 B FIGURE 37 C FIGURE 38 A FIGURE 38 B FIGURE 39 A FIGURE 39 B FIGURE 39 C FIGURE 40 A FIGURE 40 B PMID:2979049

  11. Corneal proteoglycan changes under vitamin A deficiency

    SciTech Connect

    Twining, S.S.; Wilson, P.M.

    1986-05-01

    The vitamin A-deficient keratinized cornea is very susceptible to ulceration possibly due to altered stromal components. In this study the proteoglycans present in the corneal stroma of vitamin A-deficient, pair-fed and normal rabbits were compared. Rabbits after weaning were placed on a vitamin A deficient diet, the same diet with retinyl palmitate added (pair-fed) or normal rabbit chow. After 5 months, the corneas of the vitamin A-deficient animals became keratinized. The corneal components were then labeled by injection of /sup 3/H-leucine and Na/sup 35/SO/sub 4/ into the anterior chamber of the eyes on 3 successive days. On the 4th day the animals were sacrificed the corneas removed and dissected. The labeled corneal stromas were extracted with 4 M GuHCl and the components separated on a DEAE-Sepharose column. The proteoglycans were eluted with 0.5 M and 1.0 M NaCl. The 1.0 M NaCl fraction (mainly keratin sulfate proteoglycans) was increased 25% in the vitamin A-deficient corneas over that for the pair-fed and normal corneas. These proteoglycans from the deficient corneas gave a different elution pattern on Octyl-Sepharose eluted with a Triton X-100 gradient than those from the pair-fed corneas. The total labeled proteoglycans were similar in the stromas from the 3 types of rabbits. These results indicate the various corneal proteoglycan ratios differ under vitamin A deficiency conditions.

  12. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    PubMed Central

    Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

    2012-01-01

    Purpose. The aim of this study was to determine and characterize the effect of topical application of benzalkonium chloride (BAK) on corneal nerves in vivo and in vitro. Methods. Thy1-YFP+ neurofluorescent mouse eyes were treated topically with vehicle or BAK (0.01% or 0.1%). Wide-field stereofluorescence microscopy was performed to sequentially image the treated corneas in vivo every week for 4 weeks, and changes in stromal nerve fiber density (NFD) and aqueous tear production were determined. Whole-mount immunofluorescence staining of corneas was performed with antibodies to axonopathy marker SMI-32. Western immunoblot analyses were performed on trigeminal ganglion and corneal lysates to determine abundance of proteins associated with neurotoxicity and regeneration. Compartmental culture of trigeminal ganglion neurons was performed in Campenot devices to determine whether BAK affects neurite outgrowth. Results. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P < 0.05). These changes were most significant after 0.1% BAK treatment. The extent of inflammatory cell infiltration in the cornea showed a significant negative correlation with NFD. Sequential in vivo imaging of corneas showed two forms of BAK-induced neurotoxicity: reversible neurotoxicity characterized by axonopathy and recovery, and irreversible neurotoxicity characterized by nerve degeneration and regeneration. Increased abundance of beta III tubulin in corneal lysates confirmed regeneration. A dose-related significant reduction in neurites occurred after BAK addition to compartmental cultures of dissociated trigeminal ganglion cells. Although both BAK doses (0.0001% and 0.001%) reduced nerve fiber length, the reduction was significantly more with the higher dose (P < 0.001). Conclusion. Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous

  13. Prevalence of corneal astigmatism before cataract surgery.

    PubMed

    Mohammadi, Mehran; Naderan, Mohammad; Pahlevani, Rozhin; Jahanrad, Ali

    2016-12-01

    The purpose of this study was to describe and analyze the prevalence and pattern of corneal astigmatism in cataract surgery candidates. In a prospective cross-sectional study, preoperative demographics, and keratometric and refractive values of cataract surgery candidates were collected from January 2013 to December 2014. Axial length (AL) and flat and steep keratometry measurements were optically measured by a partial coherence interferometry device (IOLMaster). This study consisted of 2156 eyes of 1317 patients with a mean age of 64.92 ± 11.48 (SD) (30-88 years). The mean of AL was 23.33 ± 1.37 mm, and the mean of corneal astigmatism was 1.12 ± 1.10 diopter (D) (range 0.0-7.00), in all patients. Furthermore, the mean of flat and steep keratometry were 43.70 ± 1.70 and 44.83 ± 1.79 D, respectively. Corneal astigmatism was 1.50 D or less in 1590 eyes (73.7 %), more than 1.50 D in 566 eyes (26.2 %), 3.00 D or more in 161 eyes (7.4 %), WTR in 796 eyes (36.9 %), ATR in 1010 eyes (46.8 %), and oblique in 350 eyes (16.2 %). ATR astigmatism axis significantly increased with the increase in age. Corneal astigmatism of most cataract surgery candidates fell between 0.50 and 1.50 D. The results of our study however is confined to our demographics might provide useful data for cataract patients, surgeons, and intraocular lens manufacturers for different purposes.

  14. Corneal Infection Therapy with Topical Bacteriophage Administration

    PubMed Central

    Fadlallah, Ali; Chelala, Elias; Legeais, Jean-Marc

    2015-01-01

    Staphylococcus aureus is a major pathogen in bacterial keratitis, a vision-threatening disease. Although the incidence of S. aureus keratitis varies worldwide, the increasing trend of resistance to certain antibiotics makes this condition an important, global, healthcare concern. We report the case of a 65-year-old woman with nosocomial left-eye corneal abscess and interstitial keratitis.The patient then undergo topical Phage therapy with successful results. PMID:26862360

  15. Clinical correlates of common corneal neovascular diseases: a literature review

    PubMed Central

    Abdelfattah, Nizar Saleh; Amgad, Mohamed; Zayed, Amira A; Salem, Hamdy; Elkhanany, Ahmed E; Hussein, Heba; Abd El-Baky, Nawal

    2015-01-01

    A large subset of corneal pathologies involves the formation of new blood and lymph vessels (neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization (CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis, contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatments available so far. PMID:25709930

  16. Corneal stromal demarcation line after collagen cross-linking in corneal ectatic diseases: a review of the literature

    PubMed Central

    Spadea, Leopoldo; Tonti, Emanuele; Vingolo, Enzo Maria

    2016-01-01

    Collagen cross-linking (CXL) is a relatively new conservative approach for progressive corneal ectasia, which is able to strengthen corneal tissue reforming new covalent bonds. Subjective and objective results following this method seem to be promising. In recent years, newer CXL protocols have been developed to perform more effective and less invasive procedures. The increasing diffusion of CXL in the corneal ectatic disease has increased the need to have actual indices regarding the efficacy of the treatment. Evaluation of demarcation line (DL), a transition zone between the cross-linked anterior corneal stroma and the untreated posterior corneal stroma, is considered a measurement of the depth of CXL treatment into the stroma. Some evidence in the literature emphasize that DL could be a measure of effectiveness of the CXL. On the contrary, some authors believe that the “the deeper, the better” principle is rather a simplistic approach for interpreting the clinical importance of the corneal stromal DL. PMID:27695286

  17. Meretoja's Syndrome: Lattice Corneal Dystrophy, Gelsolin Type

    PubMed Central

    Abreu, C.; Neves, M.; Oliveira, L.; Beirão, M.

    2017-01-01

    Lattice corneal dystrophy gelsolin type was first described in 1969 by Jouko Meretoja, a Finnish ophthalmologist. It is caused by an autosomal dominant mutation in gelsolin gene resulting in unstable protein fragments and amyloid deposition in various organs. The age of onset is usually after the third decade of life and typical diagnostic triad includes progressive bilateral facial paralysis, loose skin, and lattice corneal dystrophy. We report a case of a 53-year-old female patient referred to our Department of Ophthalmology by severe dry eye and incomplete eyelid closure. She had severe bilateral facial paresis, significant orbicularis, and perioral sagging as well as hypoesthesia of extremities and was diagnosed with Meretoja's syndrome at the age of 50, confirmed by the presence of gelsolin mutation. At our observation she had bilateral diminished tear film break-up time and Schirmer test, diffuse keratitis, corneal opacification, and neovascularization in the left eye. She was treated with preservative-free lubricants and topical cyclosporine, associated with nocturnal complete occlusion of both eyes, and underwent placement of lacrimal punctal plugs. Ocular symptoms are the first to appear and our role as ophthalmologists is essential for the diagnosis, treatment, and monitoring of ocular alterations in these patients. PMID:28250773

  18. Lymphatic endothelial lineage assemblage during corneal lymphangiogenesis

    PubMed Central

    Connor, Alicia L.; Kelley, Philip M.; Tempero, Richard M.

    2015-01-01

    Post natal inflammatory lymphangiogenesis presumably requires precise regulatory processes to properly assemble proliferating lymphatic endothelial cells (LECs). The specific mechanisms that regulate the assembly of LECs during new lymphatic vessel synthesis are unclear. Dynamic endothelial shuffling and rearrangement has been proposed as a mechanism of blood vessel growth. We developed genetic lineage tracing strategies using an inductive transgenic technology to track the fate of entire tandem dimer tomato positive (tdT) lymphatic vessels or small, in some cases clonal, populations of LECs. We coupled this platform with a suture induced mouse model of corneal lymphangiogenesis and used different analytic microscopy techniques including serial live imaging to study the spatial properties of proliferating tdT+ LEC progenies. LEC precursors and their progeny expanded from the corneal limbal lymphatic vessel and were assembled contiguously to comprise a subunit within a new lymphatic vessel. VE-cadherin blockade induced morphologic abnormalities in newly synthesized lymphatic vessels, but did not disrupt the tdT+ lymphatic endothelial lineage assembly. Analysis of this static and dynamic data based largely on direct in vivo observations supports a model of lymphatic endothelial lineage assemblage during corneal inflammatory lymphangiogenesis. PMID:26658452

  19. Effect of Corneal Nerve Ablation on Immune Tolerance Induced by Corneal Allografts, Oral Immunization, or Anterior Chamber Injection of Antigens

    PubMed Central

    Mo, Juan; Neelam, Sudha; Mellon, Jessamee; Brown, Joseph R.; Niederkorn, Jerry Y.

    2017-01-01

    Purpose Severing corneal nerves during corneal transplantation does not affect first corneal transplants, but abolishes immune privilege of subsequent corneal allografts. This abrogation of immune privilege is attributable to the disabling of T regulatory cells (T regs) induced by corneal transplantation. The goal of this study was to determine if severing corneal nerves induces the development of contrasuppressor (CS) cells, which disable T regs that impair other forms of immune tolerance. Methods Effect of corneal nerve ablation on immune tolerance was assessed in four forms of immune tolerance: anterior chamber–associated immune deviation (ACAID); oral tolerance; corneal transplantation, and intravenously (IV) induced immune tolerance. T regulatory cell activity was assessed by adoptive transfer and by local adoptive transfer (LAT) of suppression assays. Results Corneal nerve ablation prevented ACAID and oral tolerance, but did not affect IV-induced immune tolerance. Contrasuppressor cells blocked the action of T regs that were generated by anterior chamber injection, oral tolerance, or orthotopic corneal transplantation. The neuropeptide substance P (SP) was crucial for contrasuppressor activity as CS cells could not be induced in SP−/− mice and the SP receptor inhibitor, Spantide II, prevented the expression of CS cell activity in vivo. Contrasuppressor cells expressed CD11c surface marker that identifies dendritic cells (DC). Conclusions The loss of immune privilege produced by corneal nerve ablation following corneal transplantation extends beyond the eye and also affects immune tolerance induced through mucosal surfaces and appears to be mediated by a novel cell population of CD11c+ CS cells that disables T regs. PMID:28114571

  20. Development of new therapeutic modalities for corneal endothelial disease focused on the proliferation of corneal endothelial cells using animal models.

    PubMed

    Koizumi, Noriko; Okumura, Naoki; Kinoshita, Shigeru

    2012-02-01

    This review describes our recent attempts to develop new therapeutic modalities for corneal endothelial disease using animal models including non-human primate model in which the proliferative ability of corneal endothelial cells is severely limited, as is the case in humans. First, we describe our attempt to develop new surgical treatments using cultivated corneal endothelial cells for advanced corneal endothelial dysfunction. It includes two different approaches; a "corneal endothelial cell sheet transplantation" with cells grown on a type-I collagen carrier, and a "cell-injection therapy" combined with the application of Rho-kinase (ROCK) inhibitor. Recently, it was reported that the selective ROCK inhibitor, Y-27632, promotes cell adhesion and proliferation and inhibits the apoptosis of primate corneal endothelial cells in culture. When cultivated corneal endothelial cells were injected into the anterior chamber of animal eyes in the presence of ROCK inhibitor, endothelial cell adhesion was promoted and the cells achieved a high cell density and a morphology similar to corneal endothelial cells in vivo. We are also trying to develop a novel medical treatment for the early phase of corneal endothelial disease by the use of ROCK inhibitor eye drops. In rabbit and monkey experiments using partial endothelial dysfunction models, corneal endothelial wound healing was accelerated by the topical application of ROCK inhibitor to the ocular surface, and resulted in the regeneration of a corneal endothelial monolayer with a high endothelial cell density. We are now trying to advance the clinical application of these new therapies for patients with corneal endothelial dysfunction.

  1. Epidemic acute haemorrhagic conjunctivitis in Lagos, Nigeria.

    PubMed Central

    McMoli, T. E.; Bordoh, A. N.; Munube, G. M.; Bell, E. J.

    1984-01-01

    Enterovirus 70 has recently emerged as a causative agent of epidemic acute haemorrhagic conjunctivitis ( AHC ). This paper is a report of the first association of enterovirus 70 with epidemic AHC in Nigeria. Despite numerous symptoms, including reduction in visual acuity, eventual recovery in 2 to 3 weeks with no functional loss was the rule except in 11 patients. Five of these patients ended up with superficial corneal scarring. Two had evisceration for unresolving panophthalmitis, while 4 went blind from ruptured corneal abscesses or ulcers. All the 11 patients had treated themselves or used traditional medications. None of the patients had signs of involvement of the central nervous system. PMID:6326796

  2. Intratympanic steroids injection is effective for the treatment of drop attacks with Ménière's disease and delayed endolymphatic hydrops

    PubMed Central

    Liu, Bo; Leng, Yangming; Zhou, Renhong; Liu, Jingjing; Liu, Dongdong; Zhang, Su-Lin; Kong, Wei-Jia

    2016-01-01

    Abstract Drop attack (DA) associated with Ménière's disease (MD) and delayed endolymphatic hydrops (DEH) is not common and may cause life-threatening clinical problems. The intratympanic dexamethasone (ITD) is one of primary treatments for MD or DEH. Our study investigated the effect of ITD on the DA associated with endolymphatic hydrops (EH). We retrospectively reviewed 10 patients with MD- and DEH-associated DA between January 2009 and December 2013 in Outpatient Department of Otolaryngology, Union Hospital, Wuhan, China. Among them, 7 patients (5 cases with MD, 2 cases of DEH) received ITD (4 times, on weekly basis). Further repeated ITD courses or intratympanic gentamicin (ITG) were given if the vertigo was not satisfactorily controlled. The number of DA and status of vertigo control after intratympanic injection were evaluated. After a follow-up study lasting from 19 to 35 months, DA in 5 cases (71.4%) disappeared after initial ITD course. In 2 cases, DA was altogether controlled after an additional intratympanic injection (repeated ITD or/and ITG). This study showed that ITD promises to be a first-line conservative treatment for MD- or DEH-related DA since the steroid possesses no inner-ear toxicity. Furthermore, for MD- or DEH-related DA refractory to ITD, ITG can be an effective alternative. PMID:28033296

  3. Gelatinous drop-like corneal dystrophy: a review.

    PubMed

    Kaza, Hrishikesh; Barik, Manas R; Reddy, Mamatha M; Mittal, Ruchi; Das, Sujata

    2017-01-01

    Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive form of corneal dystrophy characterised by subepithelial and stromal amyloid deposits. It is relatively common in Japan. It usually presents in the first two decades of life with subepithelial nodular lesions that later coalesce to form mulberry-like opacities. Although various surgical modalities have been attempted, recurrence remains a major challenge.

  4. Genomics of corneal wound healing: a review of the literature.

    PubMed

    Maycock, Nick J R; Marshall, John

    2014-05-01

    Corneal wound healing is a complex process: its mechanisms and the underlying genetic control are not fully understood. It involves the integrated actions of multiple growth factors, cytokines and proteases produced by epithelial cells, stromal keratocytes, inflammatory cells and lacrimal gland cells. Following an epithelial insult, multiple cytokines are released triggering a cascade of events that leads to repair the epithelial defect and remodelling of the stroma to minimize the loss of transparency and function. In this review, we examine the literature surrounding the genomics of corneal wound healing with respect to the following topics: epithelial and stromal wound healing (including inhibition); corneal neovascularisation; the role of corneal nerves in wound healing; the endothelium; the role of aquaporins and aptamers. We also examine the effect of ectasia on corneal wound healing with regard to keratoconus and following corneal surgery. A better understanding of the cellular and molecular changes that occur during repair of corneal wounds will provide the opportunity to design treatments that selectively modulate key phases of the healing process resulting in scars that more closely resemble normal corneal architecture.

  5. In Vivo Corneal Biomechanical Properties with Corneal Visualization Scheimpflug Technology in Chinese Population

    PubMed Central

    Wu, Ying

    2016-01-01

    Purpose. To determine the repeatability of recalculated corneal visualization Scheimpflug technology (CorVis ST) parameters and to study the variation of biomechanical properties and their association with demographic and ocular characteristics. Methods. A total of 783 healthy subjects were included in this study. Comprehensive ophthalmological examinations were conducted. The repeatability of the recalculated biomechanical parameters with 90 subjects was assessed by the coefficient of variation (CV) and intraclass correlation coefficient (ICC). Univariate and multivariate linear regression models were used to identify demographic and ocular factors. Results. The repeatability of the central corneal thickness (CCT), deformation amplitude (DA), and first/second applanation time (A1/A2-time) exhibited excellent repeatability (CV% ≤ 3.312% and ICC ≥ 0.929 for all measurements). The velocity in/out (Vin/out), highest concavity- (HC-) radius, peak distance (PD), and DA showed a normal distribution. Univariate linear regression showed a statistically significant correlation between Vin, Vout, DA, PD, and HC-radius and IOP, CCT, and corneal volume, respectively. Multivariate analysis showed that IOP and CCT were negatively correlated with Vin, DA, and PD, while there was a positive correlation between Vout and HC-radius. Conclusion. The ICCs of the recalculated parameters, CCT, DA, A1-time, and A2-time, exhibited excellent repeatability. IOP, CCT, and corneal volume significantly influenced the biomechanical properties of the eye. PMID:27493965

  6. Biophysical aspects of corneal and lenticular transparency.

    PubMed

    Lerman, S

    1984-01-01

    The chemical composition and morphology of the cornea and lens can provide significant information regarding what wavelengths of nonionizing radiation these two tissue should absorb and transmit. Such data, including a variety of parameters determined by biophysical techniques, can provide us with information regarding the molecular basis for corneal and lenticular transparency and the subtle changes occurring with aging and ambient radiation exposure during our lifetime. The biophysical approach (fluorescence and NMR spectroscopy) has already provided new clinical tools for studying and delineating the initial events responsible for eventual opacification in these two tissues, months to years before they become manifest by current conventional clinical methods of examination.

  7. Automatic system for corneal ulcer diagnostic

    NASA Astrophysics Data System (ADS)

    Ventura, Liliane; de Sousa, Sidney J. F.

    1997-05-01

    Corneal Ulcer is a very common disease in agricultural countries and it is responsible for 10% of the blindness causes. One of the main aspects to be observed in these cases is the increasing or decreasing of the affected area. We have been developing an automatic optical system in order to evaluate the affected area (the ulcer) to be implemented in a public hospital (400 patients per week are analyzed). The optical system is implemented in a Slit Lamp and connected to a CCD detector. The image is displayed in a PC monitor by a commercial frame grabber and a dedicated software for determining the area of the ulcer has been developed.

  8. Secondary Endolymphatic Hydrops (SEH)

    MedlinePlus

    ... and aural fullness. The attacks typically occur at intervals of weeks to months, with symptom-free periods ... a balanced diet in moderate amounts at regular intervals—with meals and snacks of a consistent size, ...

  9. Applanation optical coherence elastography: noncontact measurement of intraocular pressure, corneal biomechanical properties, and corneal geometry with a single instrument

    NASA Astrophysics Data System (ADS)

    Singh, Manmohan; Han, Zhaolong; Nair, Achuth; Schill, Alexander; Twa, Michael D.; Larin, Kirill V.

    2017-02-01

    Current clinical tools provide critical information about ocular health such as intraocular pressure (IOP). However, they lack the ability to quantify tissue material properties, which are potent markers for ocular tissue health and integrity. We describe a single instrument to measure the eye-globe IOP, quantify corneal biomechanical properties, and measure corneal geometry with a technique termed applanation optical coherence elastography (Appl-OCE). An ultrafast OCT system enabled visualization of corneal dynamics during noncontact applanation tonometry and direct measurement of micro air-pulse induced elastic wave propagation. Our preliminary results show that the proposed Appl-OCE system can be used to quantify IOP, corneal biomechanical properties, and corneal geometry, which builds a solid foundation for a unique device that can provide a more complete picture of ocular health.

  10. Prior Corneal Scarification and Injection of Immune Serum are Not Required Before Ocular HSV-1 Infection for UV-B-Induced Virus Reactivation and Recurrent Herpetic Corneal Disease in Latently Infected Mice

    PubMed Central

    BenMohamed, Lbachir; Osorio, Nelson; Khan, Arif A.; Srivastava, Ruchi; Huang, Lei; Krochmal, John J.; Garcia, Jairo M.; Simpson, Jennifer L.; Wechsler, Steven L.

    2017-01-01

    Purpose Blinding ocular herpetic disease in humans is due to spontaneous reactivation of herpes simplex virus type 1 (HSV-1) from latency, rather than to primary acute infection. Mice latently infected with HSV-1 undergo little or no in vivo spontaneous reactivation with accompanying virus shedding in tears. HSV-1 reactivation can be induced in latently infected mice by several in vivo procedures, with UV-B-induced reactivation being one commonly used method. In the UV-B model, corneas are scarified (lightly scratched) just prior to ocular infection to increase efficiency of the primary infection and immune serum containing HSV-1 neutralizing antibodies is injected intraperitoneally (i.p.) to increase survival and decrease acute corneal damage. Since scarification can significantly alter host gene transcription in the cornea and in the trigeminal ganglia (TG; the site of HSV-1 latency) and since injection of immune serum likely modulates innate and adaptive herpes immunity, we investigated eliminating both treatments. Material and Methods Mice were infected with HSV-1 with or without corneal scarification and immune serum. HSV-1 reactivation and recurrent disease were induced by UV-B irradiation. Results When corneal scarification and immune serum were both eliminated, UV-B irradiation still induced both HSV-1 reactivation, as measured by shedding of reactivated virus in tears and herpetic eye disease, albeit at reduced levels compared to the original procedure. Conclusion Despite the reduced reactivation and disease, avoidance of both corneal scarification and immune serum should improve the clinical relevance of the UV-B mouse model. PMID:26398722

  11. Corneal endothelial glutathione after photodynamic change

    SciTech Connect

    Hull, D.S.; Riley, M.V.; Csukas, S.; Green, K.

    1982-03-01

    Rabbit corneal endothelial cells perfused with 5 X 10(-6)M rose bengal and exposed to incandescent light demonstrated no alteration of either total of or percent oxidized glutathione after 1 hr. Addition of 5400 U/ml catalase to the perfusing solution had no effect on total glutathione levels but caused a marked reduction in percent oxidized glutathione in corneas exposed to light as well as in those not exposed to light. Substitution of sucrose for glucose in the perfusing solution had no effect on total or percent oxidized glutathione. Perfusion of rabbit corneal endothelium with 0.5 mM chlorpromazine and exposure to ultraviolet (UV) light resulted in no change in total glutathione content. A marked reduction in percent oxidized glutathione occurred, however, in corneas perfused with 0.5 mM chlorpromazine both in the presence and absence of UV light. It is concluded that photodynamically induced swelling of corneas is not the result of a failure of the glutathione redox system.

  12. Corneal astigmatism measuring module for slit lamps

    NASA Astrophysics Data System (ADS)

    Ventura, L.; Riul, C.; Sousa, S. J. F.; DeGroote, J. G. S.; Rosa Filho, A. B.; Oliveira, G. C. D.

    2006-06-01

    We have developed an automatic keratometer module for slit lamps that provides automatic measurements of the radii of the corneal curvature. The system projects 72 light spots displayed in a precise circle at the examined cornea. The displacement and deformation of the reflected image of these light spots are analysed providing the keratometry. Measurements in the range of 26.8-75 D can be obtained and a self-calibration system has been specially designed in order to keep the system calibrated. Infrared LEDs indicate automatically which eye is being examined. Volunteer patients (492) have been submitted to the system and the results show that our system has a high correlation factor with the commercially available manual keratometers and the keratometry measurements from a topographer. Our developed system is 95% in agreement with the corneal topographer (Humphrey—Atlas 995 CZM) and the manual keratometer (Topcon OM-4). The system's nominal precision is 0.05 mm for the radii of curvature and 1° for the associated axis. This research has been supported by Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP).

  13. Bilateral Keratectasia 34 Years after Corneal Transplant

    PubMed Central

    Valldeperas, Xavier; Angi, Martina; Romano, Vito; Romano, Mario R.

    2010-01-01

    We report the clinical findings of a patient with severe bilateral keratectasia 34 years after a penetrating keratoplasty (PK) in both eyes. An otherwise healthy 67-year-old man complained of deterioration of the eyesight in both eyes over the last 6 months. The patient was diagnosed with bilateral keratoconus at the age of 32 years, and he underwent a bilateral PK. At presentation, visual acuity was 20/200 in the right eye and light perception in the left eye. A Pentacam pachymetric map revealed a central pachymetry of 720 μm in the right eye and of 710 μm in the left eye, as well as an average paracentral pachymetry of 436 and 270 μm in the 9-mm zone in the right and the left eye, respectively. Corneal topography revealed bilateral irregular and asymmetric bowing with generalized steepening and high corneal power. We describe a case of bilateral keratectasia 34 years after PK in a patient who was originally diagnosed with bilateral keratoconus. PMID:20737056

  14. Corneal calcification after amniotic membrane transplantation

    PubMed Central

    Anderson, S B; de Souza, R Ferreira; Hofmann-Rummelt, C; Seitz, B

    2003-01-01

    Background/aims: Amniotic membrane transplantation (AMT) has become well established as a treatment for chronic epithelial defects, conjunctival reconstruction, and partial limbal cell deficiency. The aim of this study was to describe cases of corneal calcification following AMT and to search for risk factors that might predispose to this unusual finding. Methods: Details of 117 AMTs on 93 corneas of 91 patients with a follow up period of at least 1 month performed since 1999 were collected prospectively. In those with calcification clinical photographs were studied and the medical records retrospectively examined. Results: 15 calcifications in 117 AMTs (12.8%) were identified, occurring 3–17 (median 6.1) weeks after AMT, during a follow up period of 4–151 (median 25) weeks. Overall epithelial healing rate was 83%. Calcification covered a surface area between 0.7–40.5 mm2 maximum size with varied morphology. The primary diagnosis was diverse. Risk factors included the use of phosphate eye drops and pre-existing calcification in the operative or other eye. No patient with a “patch” AMT developed calcification. Conclusions: Corneal calcification occurs after some cases of AMT. A common risk factor was the postoperative use of phosphate containing eye drops. PMID:12714401

  15. [New stimulants of corneal reparative regeneration].

    PubMed

    Egorov, E A; Kalinin, N I; Kiiasov, A P

    1999-01-01

    The efficacy of corneregel, a drug containing pantothenic acid, a component of coenzyme A, in healing of corneal wounds has been evaluated. The study was carried out on 19 rabbits (38 eyes) with standard corneal defect made with a 5-mm trephine for lamellar transplantation of the cornea, divided into 2 groups: 1) instillations of corneregel (10 eyes) and 0.25% levomycetin solution (10 eyes) and 2) 20% solcoseryl gel (9 eyes) and 0.25% levomycetin (9 eyes). Time course of changes were evaluated by biomicroscopy (fluorescent test), histologically (hematoxylin-eosin staining), and immunohistochemically after 1, 2, 4, 7, 30, and 90 days. Proliferative activity was studied by expression of the proliferating cell nuclear antigen and the migration capacity of cells by expression of alpha-smooth muscle actin. The terms of epithelialization were as follows: corneregel 10 +/- 7 h, 20% solcoseryl gel 108 +/- 10 h, levomycetin 124 +/- 6.93 h. Earlier epithelialization in the corneregel group was apparently due to increased expression of alpha-smooth muscle actin and increase in the cell migration capacity. Hence, corneregel is recommended for practical use as a stimulant of reparative regeneration of the cornea.

  16. Impact of Hydration Media on Ex Vivo Corneal Elasticity Measurements

    PubMed Central

    Dias, Janice; Ziebarth, Noël M.

    2014-01-01

    Objectives To determine the effect of hydration media on ex vivo corneal elasticity. Methods Experiments were conducted on forty porcine eyes retrieved from an abattoir (10 eyes each for PBS, BSS, Optisol, 15% Dextran). The epithelium was removed and the cornea was excised with an intact scleral rim and placed in 20% Dextran overnight to restore its physiological thickness. For each hydration media, corneas were evenly divided into two groups: one with an intact scleral rim and the other without. Corneas were mounted onto a custom chamber and immersed in a hydration medium for elasticity testing. While in each medium, corneal elasticity measurements were performed for 2 hours: at 5-minute intervals for the first 30 minutes and then 15-minute intervals for the remaining 90 minutes. Elasticity testing was performed using nanoindentation with spherical indenters and Young’s modulus was calculated using the Hertz model. Thickness measurements were taken before and after elasticity testing. Results The percentage change in corneal thickness and elasticity was calculated for each hydration media group. BSS, PBS, and Optisol showed an increase in thickness and Young’s moduli for corneas with and without an intact scleral rim. 15% Dextran exhibited a dehydrating effect on corneal thickness and provided stable maintenance of corneal elasticity for both groups. Conclusions Hydration media affects the stability of corneal thickness and elasticity measurements over time. 15% Dextran was most effective in maintaining corneal hydration and elasticity, followed by Optisol. PMID:25603443

  17. Growing Three-Dimensional Corneal Tissue in a Bioreactor

    NASA Technical Reports Server (NTRS)

    Spaulding, Glen F.; Goodwin, Thomas J.; Aten, Laurie; Prewett, Tacey; Fitzgerald, Wendy S.; OConnor, Kim; Caldwell, Delmar; Francis, Karen M.

    2003-01-01

    Spheroids of corneal tissue about 5 mm in diameter have been grown in a bioreactor from an in vitro culture of primary rabbit corneal cells to illustrate the production of optic cells from aggregates and tissue. In comparison with corneal tissues previously grown in vitro by other techniques, this tissue approximates intact corneal tissue more closely in both size and structure. This novel three-dimensional tissue can be used to model cell structures and functions in normal and abnormal corneas. Efforts continue to refine the present in vitro method into one for producing human corneal tissue to overcome the chronic shortage of donors for corneal transplants: The method would be used to prepare corneal tissues, either from in vitro cultures of a patient s own cells or from a well-defined culture from another human donor known to be healthy. As explained in several articles in prior issues of NASA Tech Briefs, generally cylindrical horizontal rotating bioreactors have been developed to provide nutrient-solution environments conducive to the 30 NASA Tech Briefs, October 2003 growth of delicate animal cells, with gentle, low-shear flow conditions that keep the cells in suspension without damaging them. The horizontal rotating bioreactor used in this method, denoted by the acronym "HARV," was described in "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662), NASA Tech Briefs, Vol. 16, No. 5 (May, 1992), page 150.

  18. Characteristics of corneal lens chitin in dragonfly compound eyes.

    PubMed

    Kaya, Murat; Sargin, Idris; Al-Jaf, Ivan; Erdogan, Sevil; Arslan, Gulsin

    2016-08-01

    Chitin in the compound eyes of arthropods serves as a part of the visual system. The quality of chitin in such highly specialised body parts deserves more detailed examination. Chitin in the corneal (ommatidial) lenses of dragonfly (Sympetrum fonscolombii) compound eyes was isolated by using the classical chemical method. The chitin content of the corneal lenses was determined to be quite high (20.3±0.85%). The FT-IR analysis showed that corneal lens chitin was in the α-form as found in all arthropod species where mechanical strength is required. The surface morphology analysis by scanning electron microscopy revealed that the outer part of corneal lenses consisted of long chitin fibrils with regular arrays of papillary structures while the smoother inner part had concentric lamellated chitin formation with shorter chitin nanofibrils. Chitinase enzymatic digestion studies, elemental analysis results and the degree of acetylation value showed the purity of chitin samples from corneal lens. The maximum degradation temperature value of the corneal lens chitin was observed at 369.2°C. X-ray analysis revealed that corneal lens chitin has high crystallinity index; 96.4%. Identification of chitin found in ommaditia of insect compound eyes can provide insights into insect vision and chitin-based optical material design studies.

  19. Topical Ranibizumab as a Treatment of Corneal Neovascularization

    PubMed Central

    Ferrari, Giulio; Dastjerdi, Mohammad H.; Okanobo, Andre; Cheng, Sheng-Fu; Amparo, Francisco; Nallasamy, Nambi; Dana, Reza

    2014-01-01

    Purpose To examine the effect of topical ranibizumab on clinically stable corneal neovascularization (NV). Methods This was a prospective, open-label, monocentric, uncontrolled, non-comparative study. Ten eyes of 9 patients with corneal NV received topical ranibizumab (1%) 4 times a day for 3 weeks with a follow-up of 16 weeks. The main corneal neovascularization outcome measures were: neovascular area (NA), the area occupied by the corneal neovessels; vessel caliber (VC), the mean diameter of the corneal neovessels; and invasion area (IA), the fraction of the total cornea area covered by the vessels. This study was conducted at the Massachusetts Eye and Ear Infirmary, Boston, MA, USA. Results Statistically significant decreases in NA (55.3%, P<0.001), which lasted through 16 weeks, and VC (59%, P<0.001), which continued to improve up to week 16, were observed after treatment. No significant decrease was observed in IA (12.3%, P=0.49). There was no statistically significant change in visual acuity or intraocular pressure. No adverse events ascribed to the treatment were noted. Conclusions Topical application of ranibizumab is effective in reducing the severity of corneal NV in the context of established corneal NV, mostly through decrease in VC rather than IA. PMID:23407316

  20. Evaluating alternative stem cell hypotheses for adult corneal epithelial maintenance

    PubMed Central

    West, John D; Dorà, Natalie J; Collinson, J Martin

    2015-01-01

    In this review we evaluate evidence for three different hypotheses that explain how the corneal epithelium is maintained. The limbal epithelial stem cell (LESC) hypothesis is most widely accepted. This proposes that stem cells in the basal layer of the limbal epithelium, at the periphery of the cornea, maintain themselves and also produce transient (or transit) amplifying cells (TACs). TACs then move centripetally to the centre of the cornea in the basal layer of the corneal epithelium and also replenish cells in the overlying suprabasal layers. The LESCs maintain the corneal epithelium during normal homeostasis and become more active to repair significant wounds. Second, the corneal epithelial stem cell (CESC) hypothesis postulates that, during normal homeostasis, stem cells distributed throughout the basal corneal epithelium, maintain the tissue. According to this hypothesis, LESCs are present in the limbus but are only active during wound healing. We also consider a third possibility, that the corneal epithelium is maintained during normal homeostasis by proliferation of basal corneal epithelial cells without any input from stem cells. After reviewing the published evidence, we conclude that the LESC and CESC hypotheses are consistent with more of the evidence than the third hypothesis, so we do not consider this further. The LESC and CESC hypotheses each have difficulty accounting for one main type of evidence so we evaluate the two key lines of evidence that discriminate between them. Finally, we discuss how lineage-tracing experiments have begun to resolve the debate in favour of the LESC hypothesis. Nevertheless, it also seems likely that some basal corneal epithelial cells can act as long-term progenitors if limbal stem cell function is compromised. Thus, this aspect of the CESC hypothesis may have a lasting impact on our understanding of corneal epithelial maintenance, even if it is eventually shown that stem cells are restricted to the limbus as proposed

  1. Impact of facial conformation on canine health: corneal ulceration.

    PubMed

    Packer, Rowena M A; Hendricks, Anke; Burn, Charlotte C

    2015-01-01

    Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled) skull shape, the presence of a nasal fold (wrinkle), and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not), or if a previous diagnosis of corneal ulcer(s) was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%), small breed dogs (mean± SE weight: 11.4±1.1 kg), with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio <0.5) were twenty times more likely to be affected than non-brachycephalic dogs. A 10% increase in relative eyelid aperture width more than tripled the ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare.

  2. Blepharokeratoconjunctivitis in childhood: corneal involvement and visual outcome

    PubMed Central

    Rodríguez-García, A; González-Godínez, S; López-Rubio, S

    2016-01-01

    Purpose The main objective of this study is to describe the prevalence, degree and risk of corneal involvement, and visual impact in a pediatric population with blepharokeratoconjunctivitis (BKC). Methods Retrospective, observational, case–control study. Clinical records of patients ≤16 years old with BKC seen between 2006 and 2012 were reviewed. The prevalence and relative risk of corneal involvement was evaluated between patients with and without corneal affection through a univariate and multivariate analysis with logistic regression. Visual acuity at presentation and at last follow-up visit was also analyzed. Results One hundred and fourteen children with BKC, with a male-to-female ratio of 1 : 1 and a mean age at diagnosis of 9.13 years. The mean follow-up time was 26.4 (±25) months. Corneal involvement was present in 39.5% of patients, varying from superficial punctate keratitis to perforation. Corneal changes were not seen in children under 4 years old. The risk of corneal affection was greater in patients with photophobia, hordeolum, female gender and asymmetric disease (OR of 2.69, 11.6, 2.35 and 2.77, respectively). The mean best-corrected visual acuity at presentation was 0.20 (corneal affected group), compared to 0.11 (unaffected group; P=0.02). Conclusions Our study showed an older age at time of diagnosis and a worse visual outcome in patients with BKC and corneal disease compared with previous reports. Early diagnosis and detection of risk factors for corneal involvement, as well as adequate treatment, is mandatory to prevent serious long-term visual repercussions in children with BKC. PMID:26634709

  3. Increased corneal temperature in drug-free male schizophrenia patients.

    PubMed

    Shiloh, Roni; Portuguese, Shirley; Bodinger, Liron; Katz, Nachum; Sigler, Maianit; Hermesh, Haggai; Munitz, Hanan; Weizman, Abraham

    2003-01-01

    Schizophrenia patients may exhibit altered body temperature. We hypothesized that drug-free patients may have a higher corneal temperature than normal subjects. The corneal temperature of seven remitted drug-free schizophrenia outpatients and seven healthy volunteers was evaluated with a flir thermal imaging camera. A significantly higher corneal temperature was observed in the patient group (34.60+/-1.89 vs. 33.05+/-0.58 degrees C; P=0.005) and it correlated with their BPRS score (r=0.82; P=0.024). The relevance of these preliminary findings merit further investigation.

  4. Repositioning of pedicle conjunctival flap performed for refractory corneal ulcer.

    PubMed

    Sharma, Ashok; Mohan, Kanwar; Sharma, Rajan; Nirankari, Verinder S

    2014-01-01

    A 50-year-old male was referred with a previous history of conjunctival flap (CF) for a nonhealing fungal corneal ulcer with extreme corneal thinning in the right eye. The peritomy for the CF extended from 6:30 to 9:30 clock h on the cornea. The CF was disengaged, peritomy area deepithelialized, and CF was repositioned. He later underwent penetrating keratoplasty and achieved 20/40 best corrected visual acuity. The authors present a new concept for surgically repositioning CF s to the original site immediately after healing of the corneal ulcer.

  5. Corneal modeling using conic section fits of PAR corneal topography system measurements

    NASA Astrophysics Data System (ADS)

    Zipper, Stanley; Manns, Fabrice; Fernandez, Viviana; Sandadi, Samith; Ho, Arthur; Parel, Jean-Marie A.

    2001-06-01

    The purpose of this study was to measure the average shape and variability of human corneas and to develop a tool for analyzing, height, curvature, and aberrations based on a conic section model. Fresh Eye Bank Eyes were placed in Dextran until the corneal thickness reached a physiological value. The eyes were placed in a custom made holder and measured using an intraoperative PAR Corneal Topography System (CTS) mounted on an operation microscope. Topography was measured before and after removal of the epithelium. A series of MATLAB functions were written to analyze the raw-z (height) data in polar coordinates. The functions fit conic sections to the PAR CTS data along hemi-meridians at 5 degree(s) intervals. The conic shape factor and apical radius were used to calculate and display the curvature. The dependence of these parameters with meridional position was examined.

  6. Corneal melanosis successfully treated using topical mitomycin-C and alcohol corneal epitheliectomy: a 3-year follow-up case report.

    PubMed

    Balcı, Mehmet; Yağcı, Ramazan; Güler, Emre; Haltaş, Hacer; Duman, Rahmi; Hepşen, İbrahim F

    2015-01-01

    We report a case of primary acquired corneal melanosis without atypia associated with corneal haze in a patient with a history of limbal malignant melanoma and the effect of mitomycin-C. A 75-year-old woman with a history of limbal malignant melanoma presented with loss of vision in right eye. Corneal examination showed a patchy melanotic pigmentation with a central haze. Topical mitomycin-C improved visual acuity and corneal haze. However, the pigmented lesions persisted, and they were removed with alcohol corneal epitheliectomy. Histopathological examination demonstrated primary acquired melanosis without atypia. The lesions were successfully removed, and there were no recurrences during the follow-up period of 36 months. The association of conjunctival and corneal melanosis without atypia is a rare condition. In addition, co-existence of central corneal haze and melanosis may decrease visual acuity. Topical mitomycin-C and alcohol corneal epitheliectomy can be useful treatments in this condition.

  7. Long-term outcomes of wedge resection at the limbus for high irregular corneal astigmatism after repaired corneal laceration

    PubMed Central

    Du, Jun; Zheng, Guang-Ying; Wen, Cheng-Lin; Zhang, Xiao-Fang; Zhu, Yu

    2016-01-01

    AIM To evaluate the clinical value of wedge resection at corneal limbus in patients with traumatic corneal scarring and high irregular astigmatism. METHODS Patients with traumatic corneal astigmatism received wedge resection at least 6mo after suture removal from corneal wound. The uncorrected distance visual acuities (UCVA) and best corrected distance visual acuities (BCVA), pre- and post-operation astigmatism, spherical equivalent (SE), safety and complications were evaluated. RESULTS Ten eyes (10 patients) were enrolled in this study. Mean follow-up time after wedge resection was 37.8±15.4mo (range, 20-61mo). The mean UCVA improved from +1.07±0.55 logMAR to +0.43±0.22 logMAR (P=0.000) and the mean BCVA from +0.50±0.30 logMAR to +0.15±0.17 logMAR (P=0.000). The mean astigmatism power measured by retinoscopy was -2.03±2.27 D postoperatively and -2.83±4.52 D preoperatively (P=0.310). The mean SE was -0.74±1.61 D postoperatively and -0.64±1.89 D preoperatively (P=0.601). Two cases developed mild pannus near the sutures. No corneal perforation, infectious keratitis or wound gape occurred. CONCLUSION Corneal-scleral limbal wedge resection with compression suture is a safe, effective treatment for poor patients with high irregular corneal astigmatism after corneal-scleral penetrating injury. Retinoscopy can prove particularly useful for high irregular corneal astigmatism when other measurements are not amenable. PMID:27366685

  8. Automatic system for corneal ulcer diagnostic: II

    NASA Astrophysics Data System (ADS)

    Ventura, Liliane; Chiaradia, Caio; Faria de Sousa, Sidney J.

    1998-06-01

    Corneal Ulcer is a deepithelization of the cornea and it is a very common disease in agricultural countries. The clinician most used parameter in order to identify a favorable ulcer evolution is the regress of the affected area. However, this kind of evaluation is subjective, once just the horizontal and vertical axes are measured based on a graduated scale and the affected area is estimated. Also, the registration of the disease is made by photographs. In order to overcome the subjectiveness and to register the images in a more accessible way (hard disks, floppy disks, etc.), we have developed an automatic system in order to evaluate the affected area (the ulcer). An optical system is implemented in a Slit Lamp (SL) and connected to a CCD detector. The image is displayed in PC monitor by a commercial frame grabber and a dedicated software for determining the area of the ulcer (precision of 20 mm) has been developed.

  9. Treatment of an 8-mm Myxoma Using Acellular Corneal Tissue

    PubMed Central

    Lim, Kyung Sup; Wee, Sung Wook

    2014-01-01

    A myxoma is a benign tumor found in the heart and in various soft tissues; however, a corneal myxoma is rare. A mucinous mass of unknown etiology was observed on the left cornea of a 32-year-old male patient. We performed deep anterior lamellar keratoplasty using acellular corneal tissue and concurrent amniotic membrane transplantation. Hematoxylin and eosin staining revealed vacuolation of the parenchyma and myxoid change in the corneal tissue that occurred in the anterior half of the corneal parenchyma. We identified a myxoid stroma by Alcian blue staining and observed collagen fibers with denatured stroma by Masson trichrome staining. The patient's visual acuity improved from light perception to 20 / 200, and the intraocular pressure remained within the normal range for one year after surgery. The transplanted cornea survived successfully with well-maintained transparency, and recurrence was not observed one year after surgery. PMID:24505204

  10. Shadow photogrammetric apparatus for the quantitative evaluation of corneal buttons.

    PubMed

    Denham, D; Mandelbaum, S; Parel, J M; Holland, S; Pflugfelder, S; Parel, J M

    1989-11-01

    We have developed a technique for the accurate, quantitative, geometric evaluation of trephined and punched corneal buttons. A magnified shadow of the frontal and edge views of a corneal button mounted on the rotary stage of a modified optical comparator is projected onto the screen of the comparator and photographed. This process takes approximately three minutes. The diameters and edge profile at any meridian photographed can subsequently be analyzed from the film. The precision in measuring the diameters of well cut corneal buttons is +/- 23 microns, and in measuring the angle of the edge profile is +/- 1 degree. Statistical analysis of inter observer variability indicated excellent reproducibility of measurements. Shadow photogrammetry offers a standardized, accurate, and reproducible method for analysis of corneal trephination.

  11. Keratoprostheses for corneal blindness: a review of contemporary devices

    PubMed Central

    Avadhanam, Venkata S; Smith, Helen E; Liu, Christopher

    2015-01-01

    According to the World Health Organization, globally 4.9 million are blind due to corneal pathology. Corneal transplantation is successful and curative of the blindness for a majority of these cases. However, it is less successful in a number of diseases that produce corneal neovascularization, dry ocular surface and recurrent inflammation, or infections. A keratoprosthesis or KPro is the only alternative to restore vision when corneal graft is a doomed failure. Although a number of KPros have been proposed, only two devices, Boston type-1 KPro and osteo-odonto-KPro, have came to the fore. The former is totally synthetic and the latter is semi-biological in constitution. These two KPros have different surgical techniques and indications. Keratoprosthetic surgery is complex and should only be undertaken in specialized centers, where expertise, multidisciplinary teams, and resources are available. In this article, we briefly discuss some of the prominent historical KPros and contemporary devices. PMID:25945031

  12. Golden angle based scanning for robust corneal topography with OCT

    PubMed Central

    Wagner, Joerg; Goldblum, David; Cattin, Philippe C.

    2017-01-01

    Corneal topography allows the assessment of the cornea’s refractive power which is crucial for diagnostics and surgical planning. The use of optical coherence tomography (OCT) for corneal topography is still limited. One limitation is the susceptibility to disturbances like blinking of the eye. This can result in partially corrupted scans that cannot be evaluated using common methods. We present a new scanning method for reliable corneal topography from partial scans. Based on the golden angle, the method features a balanced scan point distribution which refines over measurement time and remains balanced when part of the scan is removed. The performance of the method is assessed numerically and by measurements of test surfaces. The results confirm that the method enables numerically well-conditioned and reliable corneal topography from partially corrupted scans and reduces the need for repeated measurements in case of abrupt disturbances. PMID:28270961

  13. Corneal ulcers associated with disposable hydrogel contact lenses.

    PubMed

    Dunn, J P; Mondino, B J; Weissman, B A; Donzis, P B; Kikkawa, D O

    1989-08-15

    Four patients developed corneal ulcers associated with the use of disposable extended-wear hydrogel contact lenses. Bacteria were recovered from corneal ulcers in three of the patients. Three patients discarded their contact lenses after ten or more days of extended wear; the corneal ulcers in these patients developed toward the end of the wearing cycle. The fourth patient removed her contact lenses every two days for cleaning and disinfection and discarded them for a new pair on a weekly basis. Improper lens hygiene was noted in only one patient. All corneal ulcers responded to antibiotic treatment. In three patients visual acuity returned to normal, but scarring of one patient's cornea resulted in a visual acuity of 20/60.

  14. Golden angle based scanning for robust corneal topography with OCT.

    PubMed

    Wagner, Joerg; Goldblum, David; Cattin, Philippe C

    2017-02-01

    Corneal topography allows the assessment of the cornea's refractive power which is crucial for diagnostics and surgical planning. The use of optical coherence tomography (OCT) for corneal topography is still limited. One limitation is the susceptibility to disturbances like blinking of the eye. This can result in partially corrupted scans that cannot be evaluated using common methods. We present a new scanning method for reliable corneal topography from partial scans. Based on the golden angle, the method features a balanced scan point distribution which refines over measurement time and remains balanced when part of the scan is removed. The performance of the method is assessed numerically and by measurements of test surfaces. The results confirm that the method enables numerically well-conditioned and reliable corneal topography from partially corrupted scans and reduces the need for repeated measurements in case of abrupt disturbances.

  15. Corneal depositions in tyrosinaemia type I during treatment with Nitisinone

    PubMed Central

    Wisse, Robert P L; Wittebol-Post, Dienke; Visser, Gepke; van der Lelij, Allegonda

    2012-01-01

    We present a 17-year-old boy, diagnosed with tyrosinaemia type I at an age of 7 months, with new complaints of severe intermittent photophobia and burning eyes. His tyrosinaemia type I is treated with nitisinone and a protein-restricted diet. Dietary compliance is low since he entered puberty. His ocular complaints are attributable to subepithelial corneal deposits, resembling the common corneal phenotype of tyrosinaemia type II. Serum tyrosine levels were markedly elevated. Tyrosinaemia is a metabolic disease of tyrosine metabolism, subdivided into two types. Corneal deposits and photophobia are cardinal features of untreated tyrosinaemia type II, but not of type I. Novel treatment strategies (with nitisinone) for type I tyrosinaemia lead to a phenotype comparable with type II, including these corneal deposits. At follow-up visits his ocular complaints unfortunately remained unchanged, though he states his dietary compliance improved through the years. PMID:23203167

  16. Corneal gene therapy: basic science and translational perspective.

    PubMed

    Mohan, Rajiv R; Rodier, Jason T; Sharma, Ajay

    2013-07-01

    Corneal blindness is the third leading cause of blindness worldwide. Gene therapy is an emerging technology for corneal blindness due to the accessibility and immune-privileged nature of the cornea, ease of vector administration and visual monitoring, and ability to perform frequent noninvasive corneal assessment. Vision restoration by gene therapy is contingent upon vector and mode of therapeutic gene introduction into targeted cells/tissues. Numerous efficacious vectors, delivery techniques, and approaches have evolved in the last decade for developing gene-based interventions for corneal diseases. Maximizing the potential benefits of gene therapy requires efficient and sustained therapeutic gene expression in target cells, low toxicity, and a high safety profile. This review describes the basic science associated with many gene therapy vectors and the present progress of gene therapy carried out for various ocular surface disorders and diseases.

  17. Corneal Gene Therapy: Basic Science and Translational Perspective

    PubMed Central

    Mohan, Rajiv R.; Rodier, Jason T.; Sharma, Ajay

    2013-01-01

    Corneal blindness is the third leading cause of blindness worldwide. Gene therapy is an emerging technology for corneal blindness due to the accessibility and immune-privileged nature of the cornea, ease of vector administration and visual monitoring, and ability to perform frequent noninvasive corneal assessment. Vision restoration by gene therapy is contingent upon vector and mode of therapeutic gene introduction into targeted cells/tissues. Numerous efficacious vectors, delivery techniques, and approaches have evolved in last decade for developing gene-based interventions for corneal diseases. Maximizing the potential benefits of gene therapy requires efficient and sustained therapeutic gene expression in target cells, low toxicity, and a high safety profile. This review describes the basic science associated with many gene therapy vectors and the present progress of gene therapy carried out for various ocular surface disorders and diseases. PMID:23838017

  18. The management of lens damage in perforating corneal lacerations.

    PubMed Central

    Muga, R.; Maul, E.

    1978-01-01

    Lens damage is present in 30% of perforating injuries of the anterior segment of the eye. There is no consensus on whether the cataractous lens should be removed at the initial repair of the corneal laceration or later, when the eye has recovered from injury. Twenty-seven consecutive cases with a perforating corneal injury and lens damage were alternatively treated either with simultaneous corneal suturing and cataract removal or with corneal suturing and delayed cataract removal several weeks later. The difference in the frequency of complications between the 2 groups was significant. The 1-step procedure was technically easier to perform, the period of postoperative irritation was shorter, complications due to the presence of an injured lens were prevented, and visual rehabilitation occurred earlier. PMID:568933

  19. Brillouin Optical Microscopy for Corneal Biomechanics

    PubMed Central

    Scarcelli, Giuliano; Pineda, Roberto

    2012-01-01

    Purpose. The mechanical properties of corneal tissue are linked to prevalent ocular diseases and therapeutic procedures. Brillouin microscopy is a novel optical technology that enables three-dimensional mechanical imaging. In this study, the feasibility of this noncontact technique was tested for in situ quantitative assessment of the biomechanical properties of the cornea. Methods. Brillouin light-scattering involves a spectral shift proportional to the longitudinal modulus of elasticity of the tissue. A 532-nm single-frequency laser and a custom-developed ultrahigh-resolution spectrometer were used to measure the Brillouin frequency. Confocal scanning was used to perform Brillouin elasticity imaging of the corneas of whole bovine eyes. The longitudinal modulus of the bovine corneas was compared before and after riboflavin corneal collagen photo-cross-linking. The Brillouin measurements were then compared with conventional stress–strain mechanical test results. Results. High-resolution Brillouin images of the cornea were obtained, revealing a striking depth-dependent variation of the elastic modulus across the cornea. Along the central axis, the Brillouin frequency shift varied gradually from 8.2 GHz in the epithelium to 7.5 GHz near the endothelium. The coefficients of the down slope were measured to be approximately 1.09, 0.32, and 2.94 GHz/mm in the anterior, posterior, and innermost stroma, respectively. On riboflavin collagen cross-linking, marked changes in the axial Brillouin profiles (P < 0.001) were noted before and after cross-linking. Conclusions. Brillouin imaging can assess the biomechanical properties of cornea in situ with high spatial resolution. This novel technique has the potential for use in clinical diagnostics and treatment monitoring. PMID:22159012

  20. Tear Mediators in Corneal Ectatic Disorders

    PubMed Central

    Pásztor, Dorottya; Kolozsvári, Bence Lajos; Csutak, Adrienne; Berta, András; Hassan, Ziad; Ujhelyi, Bernadett; Gogolák, Péter; Fodor, Mariann

    2016-01-01

    Purpose To compare the concentrations of 11 tear mediators in order to reveal the biochemical difference between pellucid marginal degeneration (PMD) and keratoconus (KC). Methods We have designed a cross-sectional study in which patients with corneal ectasia based on slit-lamp biomicroscopy and Pentacam HR (keratometry values (K1, K2, Kmax), astigmatism, minimal radius of curvature (Rmin), corneal thickness (Apex and Min), indices (surface variation, vertical asymmetry, keratoconus, central keratoconus, height asymmetry and decentration)) were enrolled. Eyes of keratoconic patients were similar to the PMD patients in age and severity (K2, Kmax and Rmin). Non-stimulated tear samples were collected from nine eyes of seven PMD patients, 55 eyes of 55 KC patients and 24 eyes of 24 healthy controls. The mediators’ (interleukin -6, -10, chemokine ligand 5, -8, -10, matrix metalloproteinase (MMP) -9, -13, tissue inhibitor of metalloproteinases (TIMP)-1, tissue plasminogen activator, plasminogen activator inhibitor, nerve growth factor) concentrations were measured using Cytometric Bead Array. Results MMP-9 was the only mediator which presented relevant variances between the two patient groups (p = 0.005). The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively. Conclusion As far as we are aware, this is the first study that aims to reveal the biochemical differences between PMD and KC. Further studies of biomarkers to investigate the precise role of these mediators need to be defined, and it is important to confirm the observed changes in a larger study to gain further insights into the molecular alterations in PMD. PMID:27074131

  1. Imaging Microscopic Features of Keratoconic Corneal Morphology

    PubMed Central

    Georgeon, Cristina; Andreiuolo, Felipe; Borderie, Marie; Ghoubay, Djida; Rault, Josette; Borderie, Vincent M.

    2016-01-01

    Purpose: To search for gold-standard histology indicators using alternative imaging modalities in keratoconic corneas. Methods: Prospective observational case–control study. Fourteen keratoconic corneas and 20 normal corneas (10 in vivo healthy subjects and 10 ex vivo donor corneas) were examined. Images of corneas were taken by spectral domain optical coherence tomography (SD-OCT) and in vivo confocal microscopy (IVCM) before keratoplasty. The same removed corneal buttons were imaged after keratoplasty with full-field optical coherence microscopy (FFOCM) and then fixed and sent for histology. Controls consisted of normal subjects imaged in vivo with IVCM and donor corneas imaged ex vivo with FFOCM. Corneal structural changes related to pathology were noted with each imaging modality. Cell density was quantified by manual cell counting. Results: Keratoconus indicators (ie, epithelial thinning/thickening, cell shape changes, ferritin deposits, basement membrane anomalies, Bowman layer thinning, ruptures, interruptions, scarring, stromal modifications, and appearance of Vogt striae) were generally visible with all modalities. Additional features could be seen with FFOCM in comparison with gold-standard histology, particularly in the Bowman layer region, whereas the combination of SD-OCT plus IVCM detected 76% of those features detected in histology. Three-dimensional FFOCM imaging aided interpretation of two-dimensional IVCM and SD-OCT data. Basal epithelial cell and keratocyte densities were significantly lower in patients with keratoconus than those in normals (P < 0.0001). Conclusions: Structural and cellular assessment of the keratoconic cornea by means of either in vivo SD-OCT combined with IVCM or ex vivo FFOCM in both cross-sectional and en face views can detect as many keratoconus indicators as gold-standard histology. PMID:27560027

  2. Morphometrics of corneal growth in chicks raised in constant light.

    PubMed

    Wahl, Christina; Li, Tong; Choden, Tsering; Howland, Howard

    2009-03-01

    In this study we wish to augment our understanding of the effect of environment on corneal growth and morphology. To understand how corneal development of chicks raised in constant light differs from that of 'normal' eyes exposed to cyclic periods of light and dark, white Leghorn chicks were raised under either constant light (approximately 700 lux at cage top) or in 12 h light/12 h dark conditions for up to 12 weeks after hatching. To determine whether corneal expansion is uniform, some birds from each group received corneal tattoos for periodic photographic assessment. By 16 days of age, constant light corneas weighed less than light/dark regimen corneas [7.39 +/- 0.35 mg (SE) vs. 8.47 mg +/- 0.26 mg SE wet weight, P < or = 0.05], and corresponding differences were seen in corneal dry weights. Spatial expansion of the corneal surface was uniform in both groups, but the rate of expansion was slower in constant light chicks [0.0327 +/- 0.009 (SE) vs. 0.144 +/- 0.018 (SE) mm(2) day(-1) for normal chicks, P < or = 0.001]. At 1 day of age, there were 422 +/- 12.5 (SE) stromal cells 0.01 mm(-2) in the central cornea and 393 +/- 21.5 (SE) stromal cells 0.01 mm(-2 )peripherally. Although this difference is not statistically significant, the cell densities in the central cornea were always larger than those of the peripheral cornea in all eight measurements over a 10.5-week period, and this difference is significant (P < or = 0.008, binomial test). Light/dark regimen birds show no such consistent difference in cell densities between central and peripheral corneas. Thus, the density distribution of corneal stromal cells of chicks grown in constant light differs from that of normal chicks. Taken together, all these observations suggest that diurnal cycles of light and darkness are necessary for normal corneal growth.

  3. Chlorpromazine-induced skin pigmentation with corneal and lens opacities.

    PubMed

    Huff, Laura S; Prado, Renata; Pederson, Jon F; Dunnick, Cory A; Lucas, Lisa M

    2014-05-01

    Chlorpromazine is known to cause abnormal oculocutaneous pigmentation in sun-exposed areas. We present the case of a psychiatric patient who developed blue-gray pigmentation of the skin as well as corneal and lens opacities following 7 years of chlorpromazine treatment. Ten months after discontinuation of chlorpromazine, the skin discoloration and anterior lens deposits showed partial improvement, but the corneal deposits remained unchanged. A review of the literature on the reversibility of chlorpromazine-induced abnormal oculocutaneous pigmentation also is provided.

  4. Dynamic Corneal Surface Mapping with Electronic Speckle Pattern Interferometry

    NASA Astrophysics Data System (ADS)

    Iqbal, S.; Gualini, M. M. S.

    2013-06-01

    In view of the fast advancement in ophthalmic technology and corneal surgery, there is a strong need for the comprehensive mapping and characterization techniques for corneal surface. Optical methods with precision non-contact approaches have been found to be very useful for such bio measurements. Along with the normal mapping approaches, elasticity of corneal surface has an important role in its characterization and needs to be appropriately measured or estimated for broader diagnostics and better prospective surgical results, as it has important role in the post-op corneal surface reconstruction process. Use of normal corneal topographic devices is insufficient for any intricate analysis since these devices operate at relatively moderate resolution. In the given experiment, Pulsed Electronic Speckle Pattern Interferometry has been utilized along with an excitation mechanism to measure the dynamic response of the sample cornea. A Pulsed ESPI device has been chosen for the study because of its micron-level resolution and other advantages in real-time deformation analysis. A bovine cornea has been used as a sample in the subject experiment. The dynamic response has been taken on a chart recorder and it is observed that it does show a marked deformation at a specific excitation frequency, which may be taken as a characteristic elasticity parameter for the surface of that corneal sample. It was seen that outside resonance conditions the bovine cornea was not that much deformed. Through this study, the resonance frequency and the corresponding corneal deformations are mapped and plotted in real time. In these experiments, data was acquired and processed by FRAMES plus computer analysis system. With some analysis of the results, this technique can help us to refine a more detailed corneal surface mathematical model and some preliminary work was done on this. Such modelling enhancements may be useful for finer ablative surgery planning. After further experimentation

  5. Choroidal detachment in perforated corneal ulcers: frequency and management

    PubMed Central

    Singh, R; Umapathy, T; Abedin, A; Eatamadi, H; Maharajan, S; Dua, H S

    2006-01-01

    Aims To determine the frequency of choroidal detachment (CD) in eyes with non‐traumatic corneal ulcer perforation and, also, to assess the efficacy and safety of cyanoacrylate glue in sealing corneal perforations. Methods 18 eyes of 17 patients were studied. Inclusion criterion was any patient with a non‐traumatic perforated corneal ulcer. All patients had a thorough history taken and complete ophthalmic examination including B‐scan ultrasonography. Patient demographics, presence of CD, and efficacy of corneal gluing were assessed. Results Eight of the 18 eyes (44%) were documented to have a CD. Among perforations of >2 mm2, six eyes (75%) were documented to have CD compared with two eyes (20%) with perforations of ⩽2 mm2 (p = 0.054). No correlation could be determined between perforation duration and incidence of CD. Of the 15 eyes that underwent gluing, there were 13 successes (87%) and two failures (13%). Within the successes four patients (27%) required re‐gluing because of infection (one patient) or progression of melt and glue loosening (three patients). Failure was the result of severe progression of melting (one patient) and a very large perforation (one patient). Conclusion Choroidal detachment following corneal ulcer perforation is common and is more likely in larger corneal perforations. Preoperative B‐scan should be considered in cases of large corneal perforations requiring therapeutic keratoplasty to document choroidal detachment, which if large may require drainage. Cyanoacrylate glue is an effective and safe method for sealing small corneal perforations. A vigil must be maintained for infection while the glue and bandage contact lens are in situ. PMID:16723362

  6. 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

  7. [The use of iontophoresis in corneal crosslinking technique].

    PubMed

    Stanca, Horia T; Tabacaru, Bogdana

    2013-01-01

    Iontophoresis is a method of facilitating the penetration of a drug through an intact tissue in the presence of an low intensity electrical current. In corneal crosslinking technique, iontophoresis is used for transepitelial impregnation of cornea with riboflavin. Compared to passive technique of corneal impregnation, iontophoresis shortens the time needed for impregnation, the time of exposure to UVA radiation and does not require de-epithelialisation.

  8. Immunohistochemical analysis of lattice corneal dystrophies types I and II.

    PubMed Central

    Kivelä, T; Tarkkanen, A; McLean, I; Ghiso, J; Frangione, B; Haltia, M

    1993-01-01

    Corneal buttons from four patients with lattice corneal dystrophy (LD) type I, thought to be an isolated corneal amyloidosis, and from six patients with LD type II, part of systemic familial amyloidosis, Finnish type (FAF; Meretoja's syndrome), were studied by immunohistochemistry to determine the differential distribution in the amyloid deposits of amyloid P component (AP), mutated gelsolin specific for FAF, and native gelsolin. In both types of LD, antibodies to AP labelled lattice lines and a discontinuous layer of amyloid deposits under Bowman's layer. In LD type II, particularly, they also reacted with streak-like amyloid deposits between corneal almellae, especially in the limbal region. While the anti-FAF antiserum strongly labelled all amyloid deposits in LD type II, it failed to react unequivocally with them in LD type I. Both in LD type I and in two control specimens representing granular dystrophy, the monoclonal antibody (MAb) GS-2C4 to gelsolin faintly labelled some deposits, while in LD type II it reacted non-homogeneously with most amyloid deposits. In all specimens, MAb GS-2C4 labelled corneal epithelial cells and occasional stromal keratocytes and endothelial cells. The results suggest that Meretoja's syndrome, a systemic disease, can be diagnosed even retrospectively from corneal buttons subjected to histopathological study. Images PMID:8110676

  9. Minimizing the risk of disease transmission during corneal tissue processing.

    PubMed

    Lindquist, Thomas D; Miller, Thomas D; Elsen, Jennifer L; Lignoski, Paul J

    2009-06-01

    Corneal transplantation is undergoing significant change because the dysfunctional portion of the cornea may now be selectively transplanted. After recovery of corneoscleral tissue, further processing of such tissue as in microkeratome preparation of endothelial keratoplasty lenticules is defined as "open-container processing" by the Eye Bank Association of America. Airborne bacterial contamination during preparation of corneal tissue is a potential source of postoperative infection. This review addresses ways to minimize the risk of disease transmission as corneal tissue is processed for lamellar keratoplasty, endothelial keratoplasty, or femtosecond laser-assisted penetrating keratoplasty and to minimize risk to eye bank personnel or physicians preparing the tissue. Secondly, quality assurance measures are described that qualify the environment in which corneal tissue is being processed. We propose that the environment in which corneal tissue is being processed must be able to demonstrate acceptable levels of airborne microbial contamination annually as measured by settle plates to estimate airborne bacterial sedimentation. It is recommended that any environment where corneal tissue is prepared should meet the minimum standard of a conventional operating room which is <25 colony-forming unit per 90-mm settle plate per 1-hour exposure.

  10. Does severity of dermatochalasis in aging affect corneal biomechanical properties?

    PubMed Central

    Atalay, Kurşat; Gurez, Ceren; Kirgiz, Ahmet; Serefoglu Cabuk, Kubra

    2016-01-01

    Purpose The aim of this study was to investigate the possibility of a relationship between corneal biomechanical properties and different grades of dermatochalasis. Patients and methods Patients were assigned to four groups according to the severity of their dermatochalasis: normal (Group 1), mild (Group 2), moderate (Group 3), and severe (Group 4). An Ocular Response Analyzer device was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc). Results We found no significant differences in the mean values of the CH, CRF, and IOPcc of all groups (P=0.75, P=0.93, and P=0.11, respectively). However, CH and IOPcc were negatively correlated in Group 1, Group 2, and Group 3 patients (P=0.013, r=−0.49; P=0.015, r=−0.52; and P=0.011, r=−0.47, respectively), but this correlation was not apparent in the Group 4 patients (P=0.57, r=0.12). CRF and IOPcc were correlated, but only in Group 4 (P=0.001, r=0.66). Conclusion Severe dermatochalasis was associated with altered corneal biomechanical properties. Some of the important visual consequences of dermatochalasis and related diseases (such as floppy eyelid syndrome) can be understood by considering corneal biomechanical alterations. PMID:27274214

  11. Inhibition of NUCKS Facilitates Corneal Recovery Following Alkali Burn

    PubMed Central

    Poon, Ming-Wai; Jiang, Dan; Qin, Peng; Zhang, Yuelin; Qiu, Beiying; Chanda, Sumit; Tergaonkar, Vinay; Li, Qing; Wong, Ian Y.; Yu, Zhendong; Tse, Hung-Fat; Wong, David S. H.; Lian, Qizhou

    2017-01-01

    Corneal wound healing involves a complex cascade of cytokine-controlled cellular events, including inflammatory and angiogenesis responses that are regulated by transcriptional chromatin remodeling. Nuclear Ubiquitous Casein and cyclin-dependent Kinase Substrate (NUCKS) is a key chromatin modifier and transcriptional regulator of metabolic signaling. In this study, we investigated the role of NUCKS in corneal wound healing by comparing its effects on corneal alkali burn in NUCKS knockout (NKO) and NUCKS wild-type (NWT) mice. Our data showed that following alkali-injury, inhibition of NUCKS (NKO) accelerated ocular resurfacing and suppressed neovascularization; the cytokine profile of alkali burned corneas in NKO mice showed suppressed expression of inflammation cytokines (IL1A & IL1B); upregulated expression of antiangiogenic factor (Pigment Epithelium-derived Factor; PEDF); and downregulated expression of angiogenic factor (Vascular Endothelial Growth Factor, VEGF); in vitro, following LPS-induced NFκB activation, NKO corneal cells showed reduced expression of IL6, IP10 and TNFα. In vitro, corneal epithelial cells showed reduced NF-κb activation on silencing of NUCKS and corresponding NFκB-mediated cytokine expression was reduced. Here, we illustrate that inhibition of NUCKS played a role in cytokine modulation and facilitated corneal recovery. This reveals a potential new effective strategy for ocular burn treatment. PMID:28106169

  12. Angiopoietin-2 Blockade Promotes Survival of Corneal Transplants

    PubMed Central

    Zhang, Liwei; Li, Guangyu; Sessa, Roberto; Kang, Gyeong Jin; Shi, Meng; Ge, Shaokui; Gong, Anna Jiang; Wen, Ying; Chintharlapalli, Sudhakar; Chen, Lu

    2017-01-01

    Purpose Corneal transplantation remains the last hope for vision restoration, and lymphangiogenesis (LG) is a primary mediator of transplant rejection. This study was to investigate the specific role of angiopoietin-2 (Ang-2) in transplantation-associated LG and graft rejection. Methods Orthotopic corneal transplantation was performed between fully mismatched C57BL/6 (donor) and BALB/c (recipient) mice to assess the effects of Ang-2 blockade via neutralizing antibody. Grafts were evaluated in vivo by ophthalmic slit-lamp biomicroscopy and anterior segment optical coherence tomography (OCT) up to 8 weeks after surgery. Additionally, whole-mount corneas were analyzed for lymphatic and blood vessels and macrophages by immunofluorescent microscopy, and draining lymph nodes were assessed for donor-derived cells by flow cytometry. Results Anti-Ang-2 treatment significantly suppressed LG and graft rejection. In this study, we achieved 75% suppression of LG and 80% graft survival. Our approach also inhibited donor-derived cell trafficking to draining lymph nodes and affected macrophage morphologic phenotypes in the grafted corneas. Additionally, Ang-2 blockade also reduced central corneal thickening, a parameter strongly associated with graft rejection. Conclusions Ang-2 is critically involved in corneal transplant rejection and anti-Ang-2 treatment significantly improves the outcomes of corneal grafts. Moreover, we have shown that anterior segment OCT offers a new tool to monitor murine corneal grafts in vivo. This study not only reveals new mechanisms for transplant rejection, but also offers a novel strategy to treat it. PMID:28061513

  13. Limbal stem cells: Central concepts of corneal epithelial homeostasis.

    PubMed

    Yoon, Jinny J; Ismail, Salim; Sherwin, Trevor

    2014-09-26

    A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent studies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal surface.

  14. Mast Cells Participate in Corneal Development in Mice

    PubMed Central

    Liu, Jun; Fu, Ting; Song, Fang; Xue, Yunxia; Xia, Chaoyong; Liu, Peng; Wang, Hanqing; Zhong, Jiajun; Li, Quanrong; Chen, Jiansu; Li, Yangqiu; Cai, Dongqing; Li, Zhijie

    2015-01-01

    The development of the cornea, a highly specialized transparent tissue located at the anterior of the eye, is coordinated by a variety of molecules and cells. Here, we report that mast cells (MCs), recently found to be involved in morphogenesis, played a potentially important role in corneal development in mice. We show that two different waves of MC migration occurred during corneal development. In the first wave, MCs migrated to the corneal stroma and became distributed throughout the cornea. This wave occurred by embryonic day 12.5, with MCs disappearing from the cornea at the time of eyelid opening. In the second wave, MCs migrated to the corneal limbus and became distributed around limbal blood vessels. The number of MCs in this region gradually increased after birth and peaked at the time of eyelid opening in mice, remaining stable after postnatal day 21. We also show that integrin α4β7 and CXCR2 were important for the migration of MC precursors to the corneal limbus and that c-Kit-dependent MCs appeared to be involved in the formation of limbal blood vessels and corneal nerve fibers. These data clearly revealed that MCs participate in the development of the murine cornea. PMID:26627131

  15. Congenital Corneal Anesthesia and Neurotrophic Keratitis: Diagnosis and Management

    PubMed Central

    Mantelli, Flavio; Nardella, Chiara; Tiberi, Eloisa; Sacchetti, Marta; Bruscolini, Alice; Lambiase, Alessandro

    2015-01-01

    Neurotrophic keratitis (NK) is a rare degenerative disease of the cornea caused by an impairment of corneal sensory innervation, characterized by decreased or absent corneal sensitivity resulting in epithelial keratopathy, ulceration, and perforation. The aetiopathogenesis of corneal sensory innervation impairment in children recognizes the same range of causes as adults, although they are much less frequent in the pediatric population. Some extremely rare congenital diseases could be considered in the aetiopathogenesis of NK in children. Congenital corneal anesthesia is an extremely rare condition that carries considerable diagnostic and therapeutic problems. Typically the onset is up to 3 years of age and the cornea may be affected in isolation or the sensory deficit may exist as a component of a congenital syndrome, or it may be associated with systemic somatic anomalies. Accurate diagnosis and recognition of risk factors is important for lessening long-term sequelae of this condition. Treatment should include frequent topical lubrication and bandage corneal or scleral contact lenses. Surgery may be needed in refractory cases. The purpose of this review is to summarize and update data available on congenital causes and treatment of corneal hypo/anesthesia and, in turn, on congenital NK. PMID:26451380

  16. Tissue Engineering of the Corneal Endothelium: A Review of Carrier Materials

    PubMed Central

    Teichmann, Juliane; Valtink, Monika; Nitschke, Mirko; Gramm, Stefan; Funk, Richard H.W.; Engelmann, Katrin; Werner, Carsten

    2013-01-01

    Functional impairment of the human corneal endothelium can lead to corneal blindness. In order to meet the high demand for transplants with an appropriate human corneal endothelial cell density as a prerequisite for corneal function, several tissue engineering techniques have been developed to generate transplantable endothelial cell sheets. These approaches range from the use of natural membranes, biological polymers and biosynthetic material compositions, to completely synthetic materials as matrices for corneal endothelial cell sheet generation. This review gives an overview about currently used materials for the generation of transplantable corneal endothelial cell sheets with a special focus on thermo-responsive polymer coatings. PMID:24956190

  17. Automated image classification applied to reconstituted human corneal epithelium for the early detection of toxic damage

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni Franco; Urani, Chiara; De Servi, Barbara; Meloni, Marisa

    2010-02-01

    For a long time acute eye irritation has been assessed by means of the DRAIZE rabbit test, the limitations of which are known. Alternative tests based on in vitro models have been proposed. This work focuses on the "reconstituted human corneal epithelium" (R-HCE), which resembles the corneal epithelium of the human eye by thickness, morphology and marker expression. Testing a substance on R-HCE involves a variety of methods. Herewith quantitative morphological analysis is applied to optical microscope images of R-HCE cross sections resulting from exposure to benzalkonium chloride (BAK). The short term objectives and the first results are the analysis and classification of said images. Automated analysis relies on feature extraction by the spectrum-enhancement algorithm, which is made sensitive to anisotropic morphology, and classification based on principal components analysis. The winning strategy has been the separate analysis of the apical and basal layers, which carry morphological information of different types. R-HCE specimens have been ranked by gross damage. The onset of early damage has been detected and an R-HCE specimen exposed to a low BAK dose has been singled out from the negative and positive control. These results provide a proof of principle for the automated classification of the specimens of interest on a purely morphological basis by means of the spectrum enhancement algorithm.

  18. Corneal Limbal Stem Cell Deficiency Associated with the Anticancer Drug S-1

    PubMed Central

    Kim, Kyeong Hwan; Kim, Wan Soo

    2015-01-01

    ABSTRACT Purpose An oral antineoplastic drug, S-1, is known to be more effective with less toxicity and fewer gastrointestinal side effects than the conventional intravenous 5-fluorouracil. We report a case of limbal stem cell deficiency that occurred in a patient receiving chemotherapy using S-1 alone for gastric cancer. Case Report A 65-year-old woman with symptoms of grittiness and epiphora in both eyes for several months was referred to the ophthalmology clinic. She had been receiving S-1 orally after total gastrectomy for advanced gastric cancer. Slit lamp examination revealed an irregular hazy corneal epithelium in both eyes that extended to the center of the cornea overlying the pupil and showed late staining with fluorescein dye. Palisades of Vogt at the superior limbus were absent in both eyes. Best-corrected distance vision was 20/50 in both eyes with all other structures of the anterior and posterior segment unremarkable including a patent lacrimal drainage system. There was no change in the corneal lesions of either eye despite 3 months of topical therapy. The lesions did resolve in 4 months after discontinuation of S-1 therapy owing to acute renal failure. Conclusions Early detection of this adverse reaction before significant visual loss through regular follow-up appears to be important in patients receiving S-1 therapy. PMID:25756340

  19. Artificial corneas versus donor corneas for repeat corneal transplants

    PubMed Central

    Akpek, Esen K; Alkharashi, Majed; Hwang, Frank S; Ng, Sueko M; Lindsley, Kristina

    2014-01-01

    Background Individuals who have failed one or more full thickness penetrating keratoplasties (PKs) may be offered repeat corneal surgery using an artificial or donor cornea. An artificial or prosthetic cornea is known as a keratoprosthesis. Both donor and artificial corneal transplantations involve removal of the diseased and opaque recipient cornea (or the previously failed cornea) and replacement with another donor or prosthetic cornea. Objectives To assess the effectiveness of artificial versus donor corneas in individuals who have had one or more failed donor corneal transplantations. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2013, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2013), EMBASE (January 1980 to November 2013), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to November 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 27 November 2013. Selection criteria Two review authors independently assessed reports from the electronic searches to identify randomized controlled trials (RCTs) or controlled clinical trials (CCTs). We resolved discrepancies by discussion or consultation with a third review author. Data collection and analysis For discussion purposes, we assessed findings from observational cohort studies and non-comparative case series. No data synthesis was performed. Main results We did not identify any RCTs or CCTs comparing artificial corneas with donor corneas for repeat corneal transplantations. Authors

  20. Corneal endothelium and central corneal thickness changes in type 2 diabetes mellitus

    PubMed Central

    El-Agamy, Amira; Alsubaie, Shams

    2017-01-01

    Purpose This study was conducted to compare the corneal endothelial cell density (ECD), morphological features, and central corneal thickness (CCT) in type 2 diabetes mellitus (DM) with age-matched, nondiabetic control subjects using EM-3000 Specular Microscope. Study design This was a prospective, hospital-based, nonrandomized, case–control, observational, and quantitative study. Subjects and methods The study included 57 patients (57 eyes) with type 2 DM and 45 control (nondiabetic) subjects (45 eyes). The corneal endothelial structure and CCT were examined in all eyes by noncontact specular microscopy using EM-3000 Specular Microscope. The endothelial structure was studied for ECD, coefficient of variation of cell area (CV), and percentage of hexagonal cells. Results The study included 36 eyes without diabetic retinopathy (DR), 14 eyes with nonproliferative DR, and 7 eyes with proliferative DR. There were 26 eyes with a duration of ≤10 years and 31 eyes with a duration of >10 years. Also, there were 24 eyes with HbA1c ≤7.5% and 33 eyes with HbA1c >7.5%. ECD was significantly lower in the diabetic cornea than in control group (P=0.014). CV was higher in diabetic cornea (P=0.008). The diabetic cornea group had lower percentage of hexagonal cells than the control group, but the difference was not statistically significant (P=0.603). Also, diabetic cornea was thicker than control group, but not statistically significant (P=0.301). Conclusion This study documented that type 2 DM causes a significant reduction of ECD and increased CV (polymegathism). Also, diabetic cornea has increased CCT and lower percentage of hexagonal cells than normal subjects, but without statistical significance. PMID:28280298

  1. Inhibition of NLRP3 Inflammasome Pathway by Butyrate Improves Corneal Wound Healing in Corneal Alkali Burn

    PubMed Central

    Bian, Fang; Xiao, Yangyan; Zaheer, Mahira; Volpe, Eugene A.; Pflugfelder, Stephen C.; Li, De-Quan; de Paiva, Cintia S.

    2017-01-01

    Epithelial cells are involved in the regulation of innate and adaptive immunity in response to different stresses. The purpose of this study was to investigate if alkali-injured corneal epithelia activate innate immunity through the nucleotide-binding oligomerization domain-containing protein (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome pathway. A unilateral alkali burn (AB) was created in the central cornea of C57BL/6 mice. Mice received either no topical treatment or topical treatment with sodium butyrate (NaB), β-hydroxybutyric acid (HBA), dexamethasone (Dex), or vehicle (balanced salt solution, BSS) quater in die (QID) for two or five days (d). We evaluated the expression of inflammasome components including NLRP3, apoptosis-associated speck-like protein (ASC), and caspase-1, as well as the downstream cytokine interleukin (IL)-1β. We found elevation of NLRP3 and IL-1β messenger RNA (mRNA) transcripts, as well as levels of inflammasome component proteins in the alkali-injured corneas compared to naïve corneas. Treatment with NLRP3 inhibitors using NaB and HBA preserved corneal clarity and decreased NLRP3, caspase-1, and IL-1β mRNA transcripts, as well as NLRP3 protein expression on post-injury compared to BSS-treated corneas. These findings identified a novel innate immune signaling pathway activated by AB. Blocking the NLRP3 pathway in AB mouse model decreases inflammation, resulting in greater corneal clarity. These results provide a mechanistic basis for optimizing therapeutic intervention in alkali injured eyes. PMID:28273882

  2. Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

    PubMed Central

    Zheng, Xiuyun

    2016-01-01

    Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69 ± 4.2, 5.19 ± 3.8, and 6.23 ± 3.9 μm at the center, paracenter, and mid-periphery, resp., P < 0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r = 0.438, 0.580, and 0.504, resp., P < 0.01). Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia. PMID:27672447

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

    PubMed

    Jang, Ji Hye; Chang, Sung Dong

    2011-04-01

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

  4. ODE/PDE analysis of corneal curvature.

    PubMed

    Płociniczak, Lukasz; Griffiths, Graham W; Schiesser, William E

    2014-10-01

    The starting point for this paper is a nonlinear, two-point boundary value ordinary differential equation (BVODE) that defines corneal curvature according to a static force balance. A numerical solution to the BVODE is computed by first converting the BVODE to a parabolic partial differential equation (PDE) by adding an initial value (t, pseudo-time) derivative to the BVODE. A numerical solution to the PDE is then computed by the method of lines (MOL) with the calculation proceeding to a sufficiently large value of t such that the derivative in t reduces to essentially zero. The PDE solution at this point is also the solution for the BVODE. This procedure is implemented in R (an open source scientific programming system) and the programming is discussed in some detail. A series approximation to the solution is derived from which an estimate for the rate of convergence is obtained. This is compared to a fitted exponential model. Also, two linear approximations are derived, one of which leads to a closed form solution. Both provide solutions very close to that obtained from the full nonlinear model. An estimate for the cornea radius of curvature is also derived. The paper concludes with a discussion of the features of the solution to the ODE/PDE system.

  5. Corneal lens goggles and visual space perception.

    PubMed

    Hadani, I

    1991-10-01

    Night vision goggles are head-mounted, unity-power systems designed to allow the human operator to see and operate at night. Field experience and experimental studies have revealed many drawbacks in conventional designs that impair performance. One major drawback is the poor space perception provided by the goggles. The Hadani et al. [J. Opt. Soc. Am. 70, 60-65 (1980)] model for space perception attributes this drawback to the fact that the conventional designs shift the observer's effective center of perspective approximately 15 cm ahead and also predicts the resulting impairments. An innovative redesign is presented in this paper-the corneal lens goggles (CLG)-which brings the effective center of perspective of the goggles to coincide with the center of perspective of the eyes, thus annulling the optical length of the device. Qualitative and quantitative laboratory studies have compared the performance of the CLG and conventional goggles (type AN/PVS-5). These studies have revealed better visual and visual-motor performance with the CLG. The implications to optical design of the Hadani et al. theory and the CLG concept are discussed.

  6. Physical Aspects of Photodynamic Corneal Collagen Crosslinking

    NASA Astrophysics Data System (ADS)

    Kornfield, Julia

    2012-02-01

    Healthy vision depends on the stability of the shape of the cornea, which provides most of the lens power of the optical system of the eye. Diseases in which the cornea progressively undergoes irregular deformation over time (e.g., keratoconus) can be treated clinically by inducing additional protein-protein crosslinks using a photosensitizing drug and a tailored dose of light. Unfortunately, the treatment moving through clinical trials is toxic to cells in and on the cornea. A path to a safer treatment is offered by the nanostructure of the corneal stroma---reminiscent of a HEX phase in block copolymers with 30nm diameter collagen cylinders spaced 60nm center-to-center in a hydrogel matrix of proteoglycans and water. We show that using a photosensitizing drug that sequesters itself in the collagen fibrils can minimize the toxicity of therapeutic protein-protein cross-linking. Photorheology and transport measurements are used to quantify the parameters of a simple physical model that is useful for optimizing clinical protocols.

  7. Stereoacuity after small aperture corneal inlay implantation

    PubMed Central

    Linn, Steven H; Skanchy, David F; Quist, Tyler S; Desautels, Jordan D; Moshirfar, Majid

    2017-01-01

    Purpose The aim of this study was to compare stereoacuity before and after KAMRA corneal inlay implantation for the correction of presbyopia. Patients and methods This is a prospective study of 60 patients who underwent KAMRA inlay implantation. Patients were examined before and 6 months after surgery for stereoacuity, uncorrected distance visual acuity (UDVA), and uncorrected near visual acuity (UNVA). Results The mean stereoacuity before surgery was 29.5±28.1 arcsec (range: 20–200) and at 6 months was 29.8±26.4 arcsec (range: 20–200). The decline in stereoacuity was not statistically significant. At 6 months follow-up, UDVA was 20/25 or better in all 60 patients and UNVA was J2 (20/25) or better in 51 (85%) patients. Conclusion There is no significant change in stereoacuity following KAMRA inlay implantation. The KAMRA inlay is a good treatment option for improving near vision in presbyopic patients while preserving stereoacuity and distance vision. PMID:28182145

  8. Sutureless Corneal Transplantation Apparatus And Method

    DOEpatents

    Rowsey, J. James

    1996-12-17

    An eye with a cornea repaired without sutures comprising a donor material in the shape of a partial sphere having a generally central extent, the central extent being of the size and shape of the central portion of a cornea of an eye, the central extent having a periphery of a fixed diameter with an exterior surface in a convex configuration and an interior surface in a concave configuration and with an essentially common thickness throughout, the central extent having a plurality of corneal flaps extending radially from the periphery of the central extent, the flaps having exterior surfaces as a continuation of the exterior surface of the central extent; and a recipient eye in the shape of a partial sphere having a circular aperture in the cornea at its central portion, the central aperture being of a size and shape essentially that of the periphery of the central extent of the donor material, the aperture being of a common thickness at the periphery of the aperture, the central portion having pockets and with the central extent of the donor material located within the aperture of the recipient eye and with the flaps of the central extent being imbricated into the pockets of the recipient eye.

  9. Pulsed vs continuous light accelerated corneal collagen crosslinking: in vivo qualitative investigation by confocal microscopy and corneal OCT

    PubMed Central

    Mazzotta, C; Traversi, C; Caragiuli, S; Rechichi, M

    2014-01-01

    Purpose To assess qualitative corneal changes and penetration of pulsed and continuous light accelerated crosslinking by in vivo confocal microscopy and corneal OCT. Methods A total of 20 patients affected from progressive keratoconus were enrolled in the study. Ten eyes of 10 patients underwent an epithelium-off pulsed-light accelerated corneal collagen crosslinking (PL-ACXL) by the KXL UV-A source (Avedro Inc.) with 8 min (1 s on/1 s off) of UV-A exposure at 30 mW/cm2 and energy dose of 7.2 J/cm2; 10 eyes of 10 patients underwent an epithelium-off continuous-light accelerated corneal collagen crosslinking (CL-ACXL) at 30 mW/cm2 for 4 min. Riboflavin 0.1% dextran-free plus hydroxyl-propyl-methylcellulose solution (VibeX Rapid, Avedro Inc.) was used for a 10-min corneal soaking. Treated eyes were examined by in vivo scanning laser confocal analysis and spectral anterior segment OCT at 1, 3, and 6 months. Results Epithelial stratification and nerves regeneration improved in time, being complete at month 6 in both groups without endothelial damage. Keratocyte apoptosis in PL-ACXL was estimated at a mean depth of ∼200 μm, whereas an uneven demarcation line was detectable by confocal microscopy at a mean depth of 160 μm in CL-ACXL. Conclusion In vivo confocal microscopy and corneal OCT allowed a precise qualitative analysis of the cornea after epithelium-off PL-ACXL and CL-ACXL treatments. Apoptotic effect was higher in pulsed than in continuous light treatments, exceeding 200 μm in corneal stroma. According to different morphological data, the clinical efficacy of ACXL needs to be determined in a long-term follow-up and large cohort of patients. PMID:25060847

  10. In Vivo Imaging of Corneal Endothelial Dystrophy in Boston Terriers: A Spontaneous, Canine Model for Fuchs' Endothelial Corneal Dystrophy

    PubMed Central

    Thomasy, Sara M.; Cortes, Dennis E.; Hoehn, Alyssa L.; Calderon, Allison C.; Li, Jennifer Y.; Murphy, Christopher J.

    2016-01-01

    Purpose Boston Terriers (BTs) have a greater prevalence of corneal endothelial dystrophy (CED), in comparison to other canine breeds. Similar to Fuchs' endothelial corneal dystrophy (FECD), this condition is characterized by endothelial cell degeneration with secondary corneal edema. This study assessed corneal morphology using in vivo confocal microscopy (IVCM) and Fourier-domain optical coherence tomography (FD-OCT) in BTs with and without CED. Methods The corneas of 16 BTs with CED and 15 unaffected, age-matched BTs underwent clinical evaluation and were imaged using IVCM and FD-OCT. A two-sample t-test or Mann-Whitney rank sum test were used to statistically compare parameters between groups. Data are presented as mean ± SD or median (range). Results Mean age did not significantly differ between affected and unaffected dogs at 10.0 ± 2.0 and 10.6 ± 2.4 years, respectively (P = 0.437). Females (69%) were overrepresented among the CED-affected dogs. In CED patients, IVCM demonstrated endothelial polymegathism and pleomorphism. Corneal endothelial density was significantly less (P < 0.001) in dogs with CED (1026 ± 260 cells/mm2) versus age-matched controls (2297 ± 372 cells/mm2). Fourier-domain OCT demonstrated a significant increase (P < 0.01) in central corneal and endothelium-Descemet's complex thickness in dogs with CED versus age-matched controls at 1019 (485–1550) or 536 (464–650) μm and 32 (22–56) or 25 (15–34) μm, respectively. Conclusions Corneal endothelial dystrophy in BTs is a bilateral, adult-onset condition that shares many similarities with FECD. Thus, CED could serve as a spontaneous disease model to study the pathogenesis of and develop novel treatments for FECD. PMID:27454658

  11. Fluorouracil as a treatment for corneal papilloma in a Malayan tapir.

    PubMed

    Karpinski, Lorraine G; Miller, Christine L

    2002-09-01

    A 26-year-old, wild caught, male Malayan tapir at the Miami Metrozoo with bilateral corneal papillomas was serially immobilized and given subconjunctival injections of fluorouracil. Over the course of 17 weeks five bilateral injections of 25 mg fluorouracil were given. This treatment caused regression of the corneal lesions as evidenced by decreased lesion diameter, decreased corneal vascularity, increased corneal clarity, and improved visual function. No adverse drug effects were observed.

  12. [Suprainfected corneal injuries--the specific therapeutic aspects in 2 cases].

    PubMed

    Stefăniu, I; Niţă, N; Zemba, M; Niţulescu, C; Chirilă, D; Zamfir, C; Ionică, N

    2000-01-01

    This paper presents two cases of corneal abscess and their therapeutically approach which was the surgical treatment (penetrant keratoplasty). First case was a corneal ulcer which failed to abscess under medical therapy. The second case was a corneal abscess complicated with impending perforation after intracorneal foreign body. The particular aspects for each case are emphasized as well as the common aspects for corneal infections summarized as an algorithm.

  13. Corneal epithelial response of the primate eye to gas permeable corneal contact lenses: a preliminary report.

    PubMed

    Bergmanson, J P; Ruben, M; Chu, L W

    1984-01-01

    The comparative corneal epithelial effects of rigid gas permeable and soft contact lenses are reported in the present preliminary study using two bush baby monkeys (Galago senegalensis). Both types of lenses produced early cell death among the surface squamous cells while internally the epithelium and its nerve fibers remained normal. Sporadically small abnormal groups of cells involving two to three of the surface layers were observed in both the hard and soft lens wearing corneas. It was concluded that this represented superficial punctate keratitis (SPK). Small superficial intracellular epithelial cysts with membranous contents were infrequently noted in the gas permeable lens wearing cornea and it is suggested here that they were mild forms or precursors of those seen clinically in human corneas. Since the gas permeable lens met the corneal oxygen requirement it is postulated that the traumatic effect of the rigidity of the lens caused the cystic formation to occur. The relative hypoxia induced by the soft contact lens resulted in a mild superficial epithelial edema.

  14. Oxidized alginate hydrogels as niche environments for corneal epithelial cells.

    PubMed

    Wright, Bernice; De Bank, Paul A; Luetchford, Kim A; Acosta, Fernando R; Connon, Che J

    2014-10-01

    Chemical and biochemical modification of hydrogels is one strategy to create physiological constructs that maintain cell function. The aim of this study was to apply oxidised alginate hydrogels as a basis for development of a biomimetic niche for limbal epithelial stem cells that may be applied to treating corneal dysfunction. The stem phenotype of bovine limbal epithelial cells (LEC) and the viability of corneal epithelial cells (CEC) were examined in oxidised alginate gels containing collagen IV over a 3-day culture period. Oxidation increased cell viability (P ≤ 0.05) and this improved further with addition of collagen IV (P ≤ 0.01). Oxidised gels presented larger internal pores (diameter: 0.2-0.8 µm) than unmodified gels (pore diameter: 0.05-0.1 µm) and were significantly less stiff (P ≤ 0.001), indicating that an increase in pore size and a decrease in stiffness contributed to improved cell viability. The diffusion of collagen IV from oxidised alginate gels was similar to that of unmodified gels suggesting that oxidation may not affect the retention of extracellular matrix proteins in alginate gels. These data demonstrate that oxidised alginate gels containing corneal extracellular matrix proteins can influence corneal epithelial cell function in a manner that may impact beneficially on corneal wound healing therapy.

  15. [Macroscopic observations on corneal epithelial wound healing in the rabbit].

    PubMed

    Hayashi, K

    1991-02-01

    A newly-developed macroscope was applied to observe the healing process of corneal epithelial wound in vivo. After removing epithelium of the central cornea, the changes of the corneal surface were observed with the macroscope and the findings were compared with histological examinations. At 12 hours after abrasion, areas unstained with Richardson's staining (R staining) appeared. In the histological section, a single layer of regenerating epithelial cells covered the same area. At 24 and 36 hours after abrasion, the epithelial defects became smaller but surrounding epithelium was rough and showed dot-like staining with R solution. By 2 days, the epithelial defects disappeared. On macroscopic observation, the central corneal surface showed a pavement-like appearance. Histology revealed that the regenerating epithelium still consisted of one or two layers. At 3 days, dot-like stainings were present only in the center and the corneal surface appeared considerably smooth. Histology also showed that regenerating epithelium became columnar and multilayered, thereby suggesting stratification. By 7 days, the abraded corneal surface had recovered its smooth appearance. Histologic sections also demonstrated that the epithelium had regained its normal structure. Thus, using this macroscope, findings suggesting the process of epithelial migration and proliferation could be observed.

  16. Hydrogen prevents corneal endothelial damage in phacoemulsification cataract surgery

    PubMed Central

    Igarashi, Tsutomu; Ohsawa, Ikuroh; Kobayashi, Maika; Igarashi, Toru; Suzuki, Hisaharu; Iketani, Masumi; Takahashi, Hiroshi

    2016-01-01

    In phacoemulsification, ultrasound induces hydroxyl radical (·OH) formation, damaging corneal endothelium. Whether H2 can prevent such oxidative damage in phacoemulsification was examined by in vitro and in vivo studies. H2 was dissolved in a commercial irrigating solution. The effects of H2 against ·OH generation were first confirmed in vitro by electron-spin resonance (ESR) and hydroxyphenyl fluorescein (HPF). ESR showed a significantly decreased signal magnitude, and fluorescence intensity by oxidized HPF was significantly less in the H2-dissolved solution. The effects of H2 in phacoemulsification were evaluated in rabbits, comparing H2-dissolved and control solutions. Five hours after the procedure, the whole cornea was excised and subjected to image analysis for corneal edema, real-time semiquantitative PCR (qPCR) for heme oxygenase (HO)-1, catalase (CAT), superoxide dismutase 1 (SOD1), and SOD2 mRNA, and immunohistochemistry. Corneal edema was significantly less and the increases in anti-oxidative HO-1, CAT and SOD2 mRNA expressions were significantly suppressed in the H2 group. In addition, corneal endothelial cell expressions of two oxidative stress markers, 4-HNE and 8-OHdG, were significantly lower in the H2 group. In conclusion, H2 dissolved in the ocular irrigating solution protected corneal endothelial cells from phacoemulsification-induced oxidative stress and damage. PMID:27498755

  17. Corneal topography from spectral optical coherence tomography (sOCT)

    PubMed Central

    Ortiz, Sergio; Siedlecki, Damian; Pérez-Merino, Pablo; Chia, Noelia; de Castro, Alberto; Szkulmowski, Maciej; Wojtkowski, Maciej; Marcos, Susana

    2011-01-01

    We present a method to obtain accurate corneal topography from a spectral optical coherence tomography (sOCT) system. The method includes calibration of the device, compensation of the fan (or field) distortion introduced by the scanning architecture, and image processing analysis for volumetric data extraction, segmentation and fitting. We present examples of three-dimensional (3-D) surface topography measurements on spherical and aspheric lenses, as well as on 10 human corneas in vivo. Results of sOCT surface topography (with and without fan-distortion correction) were compared with non-contact profilometry (taken as reference) on a spherical lens, and with non-contact profilometry and state-of-the art commercial corneal topography instruments on aspheric lenses and on subjects. Corneal elevation maps from all instruments were fitted by quadric surfaces (as well as by tenth-order Zernike polynomials) using custom routines. We found that the discrepancy in the estimated radius of curvature from nominal values in artificial corneas decreased from 4.6% (without fan distortion correction) to 1.6% (after fan distortion correction), and the difference in the asphericity decreased from 130% to 5%. In human corneas, the estimated corneal radius of curvature was not statistically significantly different across instruments. However, a Bland-Altman analysis showed consistent differences in the estimated asphericity and corneal shape between sOCT topographies without fan distortion correction and the rest of the measurements. PMID:22162814

  18. Oxidized alginate hydrogels as niche environments for corneal epithelial cells

    PubMed Central

    Wright, Bernice; De Bank, Paul A; Luetchford, Kim A; Acosta, Fernando R; Connon, Che J

    2014-01-01

    Chemical and biochemical modification of hydrogels is one strategy to create physiological constructs that maintain cell function. The aim of this study was to apply oxidised alginate hydrogels as a basis for development of a biomimetic niche for limbal epithelial stem cells that may be applied to treating corneal dysfunction. The stem phenotype of bovine limbal epithelial cells (LEC) and the viability of corneal epithelial cells (CEC) were examined in oxidised alginate gels containing collagen IV over a 3-day culture period. Oxidation increased cell viability (P ≤ 0.05) and this improved further with addition of collagen IV (P ≤ 0.01). Oxidised gels presented larger internal pores (diameter: 0.2–0.8 µm) than unmodified gels (pore diameter: 0.05–0.1 µm) and were significantly less stiff (P ≤ 0.001), indicating that an increase in pore size and a decrease in stiffness contributed to improved cell viability. The diffusion of collagen IV from oxidised alginate gels was similar to that of unmodified gels suggesting that oxidation may not affect the retention of extracellular matrix proteins in alginate gels. These data demonstrate that oxidised alginate gels containing corneal extracellular matrix proteins can influence corneal epithelial cell function in a manner that may impact beneficially on corneal wound healing therapy. © 2013 The Authors. Journal of Biomedical Materials Research Part A Published byWiley Periodicals, Inc. Part A: 102A: 3393–3400, 2014. PMID:24142706

  19. Tissue adhesive to treat 2-site corneal melting associated with topical ketorolac use.

    PubMed

    Marcon, Alexandre S; Rapuano, Christopher J; Tabas, Janine G

    2003-02-01

    We report a case of a 78-year-old man presenting with 2 discrete areas of sterile corneal melting associated with chronic use of topical ketorolac after uneventful clear corneal phacoemulsification. He was treated successfully with tissue adhesive application. Patients receiving chronic topical ketorolac treatment, especially those with ocular surface abnormalities, can present with severe complications such as corneal melting.

  20. Construction of a Corneal Stromal Equivalent with SMILE-Derived Lenticules and Fibrin Glue

    PubMed Central

    Yin, Houfa; Qiu, Peijin; Wu, Fang; Zhang, Wei; Teng, Wenqi; Qin, Zhenwei; Li, Chao; Zhou, Jiaojie; Fang, Zhi; Tang, Qiaomei; Fu, Qiuli; Ma, Jian; Yang, Yabo

    2016-01-01

    The scarcity of corneal tissue to treat deep corneal defects and corneal perforations remains a challenge. Currently, small incision lenticule extraction (SMILE)-derived lenticules appear to be a promising alternative for the treatment of these conditions. However, the thickness and toughness of a single piece of lenticule are limited. To overcome these limitations, we constructed a corneal stromal equivalent with SMILE-derived lenticules and fibrin glue. In vitro cell culture revealed that the corneal stromal equivalent could provide a suitable scaffold for the survival and proliferation of corneal epithelial cells, which formed a continuous pluristratified epithelium with the expression of characteristic markers. Finally, anterior lamellar keratoplasty in rabbits demonstrated that the corneal stromal equivalent with decellularized lenticules and fibrin glue could repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization. Corneal neovascularization, graft degradation, and corneal rejection were not observed within 3 months. Taken together, the corneal stromal equivalent with SMILE-derived lenticules and fibrin glue appears to be a safe and effective alternative for the repair of damage to the anterior cornea, which may provide new avenues in the treatment of deep corneal defects or corneal perforations. PMID:27651001

  1. Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil.

    PubMed

    Almeida, Hirlana Gomes; Hida, Richard Yudi; Kara, Newton

    2016-09-01

    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and p<0.05 was the rate of rejection of the null hypothesis. From 2002 to 2014, there was an increase in the absolute number of corneal transplants, the annual rate of transplants per million people and the percentage of needed transplants performed in each of the five regions of Brazil. Family refusal and medical contraindication were the most frequent reasons for a lack of corneal donation. Although remarkable progress has been made in the last decade in each of the five Brazilian regions, health professionals' lack of preparation to approach families with donation requests at the death of a family member appears to be the main obstacle to increasing the number of corneal donations. Thus, the present study suggests the implementation of public policies to make corneal transplants more effective, particularly given that there are considerable disparities in the effectiveness with which regional needs are met and in health professionals' ability to perform transplants among the Brazilian regions, with higher rates in the South, Southeast and Midwest regions and lower rates in the North and Northeast regions.

  2. Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil

    PubMed Central

    Almeida, Hirlana Gomes; Hida, Richard Yudi; Kara-Junior, Newton

    2016-01-01

    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and p<0.05 was the rate of rejection of the null hypothesis. From 2002 to 2014, there was an increase in the absolute number of corneal transplants, the annual rate of transplants per million people and the percentage of needed transplants performed in each of the five regions of Brazil. Family refusal and medical contraindication were the most frequent reasons for a lack of corneal donation. Although remarkable progress has been made in the last decade in each of the five Brazilian regions, health professionals’ lack of preparation to approach families with donation requests at the death of a family member appears to be the main obstacle to increasing the number of corneal donations. Thus, the present study suggests the implementation of public policies to make corneal transplants more effective, particularly given that there are considerable disparities in the effectiveness with which regional needs are met and in health professionals’ ability to perform transplants among the Brazilian regions, with higher rates in the South, Southeast and Midwest regions and lower rates in the North and Northeast regions. PMID:27652836

  3. PEP-1-FK506BP inhibits alkali burn-induced corneal inflammation on the rat model of corneal alkali injury

    PubMed Central

    Kim, Dae Won; Lee, Sung Ho; Shin, Min Jea; Kim, Kibom; Ku, Sae Kwang; Youn, Jong Kyu; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Son, Ora; Sohn, Eun Jeong; Cho, Sung-Woo; Park, Jong Hoon; Kim, Hyun Ah; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-01-01

    FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI. [BMB Reports 2015; 48(11): 618-623] PMID:25817214

  4. Neuropathologic Characterization of Pontocerebellar Hypoplasia Type 6 Associated With Cardiomyopathy and Hydrops Fetalis and Severe Multisystem Respiratory Chain Deficiency due to Novel RARS2 Mutations

    PubMed Central

    Lax, Nichola Z.; Alston, Charlotte L.; Schon, Katherine; Park, Soo-Mi; Krishnakumar, Deepa; He, Langping; Falkous, Gavin; Ogilvy-Stuart, Amanda; Lees, Christoph; King, Rosalind H.; Hargreaves, Iain P.; Brown, Garry K.; McFarland, Robert; Dean, Andrew F.; Taylor, Robert W.

    2015-01-01

    Abstract Autosomal recessive mutations in the RARS2 gene encoding the mitochondrial arginyl-transfer RNA synthetase cause infantile-onset myoencephalopathy pontocerebellar hypoplasia type 6 (PCH6). We describe 2 sisters with novel compound heterozygous RARS2 mutations who presented perinatally with neurologic features typical of PCH6 but with additional features including cardiomyopathy, hydrops, and pulmonary hypoplasia and who died at 1 day and 14 days of age. Magnetic resonance imaging findings included marked cerebellar hypoplasia, gyral immaturity, punctate lesions in cerebral white matter, and unfused deep cerebral grey matter. Enzyme histochemistry of postmortem tissues revealed a near-global cytochrome c oxidase-deficiency; assessment of respiratory chain enzyme activities confirmed severe deficiencies involving complexes I, III, and IV. Molecular genetic studies revealed 2 RARS2 gene mutations: a c.1A>G, p.? variant predicted to abolish the initiator methionine, and a deep intronic c.613-3927C>T variant causing skipping of exons 6–8 in the mature RARS2 transcript. Neuropathologic investigation included low brain weights, small brainstem and cerebellum, deep cerebral white matter pathology, pontine nucleus neuron loss (in 1 sibling), and peripheral nerve pathology. Mitochondrial respiratory chain immunohistochemistry in brain tissues confirmed an absence of complexes I and IV immunoreactivity with sparing of mitochondrial numbers. These cases expand the clinical spectrum of RARS2 mutations, including antenatal features and widespread mitochondrial respiratory chain deficiencies in postmortem brain tissues. PMID:26083569

  5. Evaluation of the usefulness of three-dimensional optical coherence tomography in a guinea pig model of endolymphatic hydrops induced by surgical obliteration of the endolymphatic duct

    NASA Astrophysics Data System (ADS)

    Cho, Nam Hyun; Lee, Jang Woo; Cho, Jin-ho; Kim, Jeehyun; Jang, Jeong Hun; Jung, Woonggyu

    2015-03-01

    Optical coherence tomography (OCT) has advanced significantly over the past two decades and is currently used extensively to monitor the internal structures of organs, particularly in ophthalmology and dermatology. We used ethylenediamine tetra-acetic acid (EDTA) to decalcify the bony walls of the cochlea and investigated the inner structures by deep penetration of light into the cochlear tissue using OCT on a guinea pig model of endolymphatic hydrops (EH), induced by surgical obliteration of the endolymphatic duct. The structural and functional changes associated with EH were identified using OCT and auditory brainstem response tests, respectively. We also evaluated structural alterations in the cochlea using three-dimensional reconstruction of the OCT images, which clearly showed physical changes in the cochlear structures. Furthermore, we found significant anatomical variations in the EH model and conducted graphical analysis by strial atrophy for comparison. The physical changes included damage to and flattening of the organ of Corti-evidence of Reissner's membrane distention-and thinning of the lateral wall. These results indicate that observation of EDTA-decalcified cochlea using OCT is significant in examination of gradual changes in the cochlear structures that are otherwise not depicted by hematoxylin and eosin staining.

  6. Vision loss after inadvertent corneal perforation during lid anesthesia.

    PubMed

    Parikh, Mansi; Kwon, Young H

    2011-01-01

    A 68-year-old woman was referred for glaucoma management after inadvertent corneal perforation during eyelid anesthesia for upper eyelid blepharoplasty. A mixture of 50:50 2% lidocaine with 1:100,000 epinephrine and 0.5% bupivacaine buffered with sodium bicarbonate was injected intracamerally. Decreased vision and uncontrollable intraocular pressure resulted, despite prompt anterior chamber washout. Examination showed corneal edema, inflammation, and secondary angle closure. Intraocular pressure control with seton placement led to an improvement in vision; however, mild corneal haze remained, and specular microscopy showed endothelial cell loss, presumably secondary to local anesthetic toxicity. Inadvertent ocular penetration is a rare but serious complication of local eyelid anesthesia. Prompt recognition is essential to institute appropriate management and minimize subsequent vision loss.

  7. Technique for the selective heating of corneal stroma

    SciTech Connect

    Doss, J.D.; Albillar, J.I.

    1980-01-01

    Conventional thermokeratoplasty, which relies upon thermal conduction from the epithelium into the stroma, does not generate a desirable temperature profile through the cornea. Previous reports show that temperature levels in the epithelium and in Bowman's membrane are excessive, often resulting in damage to these structures. In addition, this study shows that when corneal thickness exceeds approximately 300 microns, the central portion of the stroma probably will not reach critical shrinkage temperature. Shrinkage only in the superficial stroma may result in minimal and transitory alterations of corneal shape. Variation in treatment results may also occur due to the difficulty in precise control of treatment duration. An alternative corneal heating technique is discussed which appears to solve these three basic problems.

  8. Fungal corneal ulcers of onion harvesters in southern Taiwan.

    PubMed

    Lin, S H; Lin, C P; Wang, H Z; Tsai, R K; Ho, C K

    1999-06-01

    Fungal corneal ulcers related to agriculture has been reported throughout the world, especially in tropical areas. Most of them were sporadic and had histories of ocular trauma or use of topical corticosteroids and topical antibiotics. Five onion harvesters had fungal corneal ulcers during the same harvest period in Southern Taiwan. The authors think that this is the first report of a group occurrence relating to agricultural workers. Although all of the patients improved after medical and surgical management, their vision was greatly decreased. It is suggested that the tropical climate, the harvest procedure, the characteristic monsoon, and lack of eye protection were involved. Therefore, the importance of the eye protection, hygiene education, and improving medical care to reduce the occurrence of fungal corneal ulcer in agriculture workers must be emphasised.

  9. Advances in corneal topography measurements with conical null-screens

    NASA Astrophysics Data System (ADS)

    Campos-García, Manuel; Cossio-Guerrero, Cesar; Huerta-Carranza, Oliver; Moreno-Oliva, Víctor I.

    2015-09-01

    In this work we report the design of a null-screen for corneal topography. To avoid the difficulties in the alignment of the test system due to the face contour (eyebrows, nose, or eyelids), we design a conical null-screen with a novel radial points distribution drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact array of circular spots if the surface is perfect. Additionally, an algorithm to compute the sagittal and meridional radii of curvature for the corneal surface is presented. The sagittal radius is obtained from the surface normal, and the meridional radius is calculated from a function fitted to the derivative of the sagittal curvature by using the surfacenormals raw data. Experimental results for the testing a calibration spherical surface are shown. Also, we perform some corneal topography measurements.

  10. Intraoperative raster photogrammetry--the PAR Corneal Topography System.

    PubMed

    Belin, M W

    1993-01-01

    The PAR Corneal Topography System (CTS) is a computer-driven corneal imaging system that uses close-range raster photogrammetry to measure and produce a topographic map of the corneal surface. The CTS determines distortion in a projected two-dimensional grid. Unlike Placido-disc-based videokeratoscopes, the PAR CTS produces a true topographic map (elevation map) and requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. Because the system uses two noncoaxial optical paths, it can be integrated into other optical devices. A modified CTS was integrated into an experimental erbium: YAG photoablative laser. The CTS successfully imaged corneas before, after, and during laser photoablation. Its ability to image nonreflective surfaces and to be integrated into other optical systems may make it suitable for intraoperative refractive monitoring.

  11. Heterodyne moiré interferometry for measuring corneal surface profile

    NASA Astrophysics Data System (ADS)

    Chang, Wei-Yao; Chen, Kun-Huang; Chen, Der-Chin; Tseng, Jung-Kai; Chen, Shyan-Tarng; Sun, Han-Ying; Chen, Jing-Heng; Hsu, Ken Y.

    2014-03-01

    This study proposes an accurate method for reconstructing the corneal surface profile. By applying a constant velocity to the projection grating along the grating plane, a series of sampling points of the sinusoidal wave, which behaves in the manner of heterodyne interferometric signals, can be recorded using a CMOS camera. The phase distribution of the moiré fringes can then be obtained using the IEEE 1241 least-square sine fitting algorithm and two-dimensional (2D) phase unwrapping. Finally, the corneal surface profile can be reconstructed by substituting the phase distribution into a specially derived equation. To validate the proposed method, the corneal surface of a pig eyeball was measured. The measurement resolution was approximately 3.5 μm. Because of the introduction of the Talbot effect, the projection moiré method, and heterodyne interferometry, this approach provides the advantages of a simple optical setup, ease of operation, high stability, and high resolution.

  12. Inhibition of corneal epithelial cell migration by cadmium and mercury

    SciTech Connect

    Ubels, J.L.; Osgood, T.B. Medical Coll. of Wisconsin, Milwaukee )

    1991-02-01

    In a previous comparative study of corneal healing in fish, the authors observed that corneal epithelial healing occurs very rapidly in vivo in the marine teleost Myoxocephalus octodecimspinosus (longhorn sculpin) with a 6-mm diameter wound on the mammalian cornea. This rapid healing which permits prompt restoration of the epithelial barrier is apparently an adaptation to the large ionic and osmotic gradients between the environment and the intraocular fluids of the fish. These observations suggested that epithelial healing in the sculpin cornea might be useful model in aquatic biomedical toxicology if an in vitro method for measurement of healing rates could be developed. In this report the authors demonstrate that sculpin eyes maintained in short-term organ culture have a rapid corneal epithelial healing response and that this model can be used to demonstrate the toxic effects of heavy metals on epithelial cell migration.

  13. Accelerated corneal collagen crosslinking: Technique, efficacy, safety, and applications.

    PubMed

    Medeiros, Carla S; Giacomin, Natalia T; Bueno, Renata L; Ghanem, Ramon C; Moraes, Haroldo V; Santhiago, Marcony R

    2016-12-01

    Corneal collagen crosslinking (CXL) is an approach used to increase the biomechanical stability of the stromal tissue. Over the past 10 years, it has been used to halt the progression of ectatic diseases. According to the photochemical law of reciprocity, the same photochemical effect is achieved with reduced illumination time and correspondingly increased irradiation intensity. Several new CXL devices offer high ultraviolet-A irradiation intensity with different time settings. The main purpose of this review was to discuss the current use of different protocols of accelerated CXL and compare the efficacy and safety of accelerated CXL with the efficacy and safety of the established conventional method. Accelerated CXL proved to be safe and effective in halting progression of corneal ectasia. Corneal shape responses varied considerably, as did the demarcation line at different irradiance settings; the shorter the exposure time, the more superficial the demarcation line.

  14. Bietti's tapetoretinal degeneration with marginal corneal dystrophy crystalline retinopathy.

    PubMed Central

    Welch, R B

    1977-01-01

    In 1937 Bietti reported a tapetoretinal degeneration with associated corneal deposits at the limbus. The hallmark of the disease was the crystalline characteristics of the retinal spots as well as those at the corneal limbus. Bagolini and Ioli-Spade in 1968 presented a 30 year follow-up on Bietti's cases and presented six additional cases. The present report delas with this entity in Orientals, a Chinese woman and a Japanese man. Corneal and conjunctival biopsy from the female patient revelaed a lipid deposition in both fibroblasts and epithelium. The term "crystalline retinopathy" has been added to the description of this entity since it defines the most characteristic feature of the syndrome. Images FIGURE 7 A FIGURE 7 B FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 2 A FIGURE 2 B FIGURE 2 C FIGURE 3 FIGURE 4 A FIGURE 4 B FIGURE 5 FIGURE 6 A FIGURE 6 B FIGURE 6 C FIGURE 8 PMID:306693

  15. Effect of acetylcysteine on experimental corneal wounds in dogs.

    PubMed

    Aldavood, S J; Behyar, R; Sarchahi, A A; Rad, M A; Noroozian, I; Ghamsari, S M; Sadeghi-Hashjin, G

    2003-01-01

    The effects of 3, 10 and 20% concentrations of acetylcysteine on experimental corneal wound healing in dogs were evaluated. Experimental corneal wounds were induced surgically, up to the depth of the anterior third of the stroma, in both eyes of 18 dogs. One of the eyes was treated topically with 0.9% NaCl solution three times a day. The contralateral eye was treated topically with acetylcysteine (3, 10 and 20% concentrations) in each of 6 cases separately. Corneal wounds were measured by fluorescein staining every day. The mean time of healing in the 3% group was significantly different from control eyes (6.17 +/- 1.94 days). It was 7.19 +/- 0.75 days in the 20% group and 7 +/- 2 days in the 10% group. The last two groups were not significantly different from the controls (9.67 +/- 3.01 days and 8.17 +/- 3.60 days, respectively).

  16. Corneal fibropapillomatosis in green sea turtles (Chelonia mydas) in Australia.

    PubMed

    Flint, M; Limpus, C J; Patterson-Kane, J C; Murray, P J; Mills, P C

    2010-05-01

    Chelonid corneal fibropapillomatosis has not previously been recorded in Australian waters. During 2008, 724 green sea turtles (Chelonia mydas) were examined in Queensland, Australia at two sites, Moreton Bay (n=155) and Shoalwater Bay (n=569), during annual monitoring. In the same calendar year, 63 turtles were submitted from various sites in southern Queensland for post-mortem examination at the University of Queensland. Four of the 787 animals (0.5%) were found to have corneal fibropapillomas of varying size, with similar gross and microscopical features to those reported in other parts of the world. Two animals with corneal fibropapillomas also had cutaneous fibropapillomas. Clinical assessment indicated that these lesions had detrimental effects on the vision of the turtles and therefore their potential ability to source food, avoid predators and interact with conspecifics. Importantly, these findings represent an emergence of this manifestation of fibropapillomatosis in green sea turtle populations in the southern Pacific Ocean.

  17. Central Corneal Thickness in Patients with Atopic Keratoconjunctivitis

    PubMed Central

    Ondas, Osman; Keles, Sadullah

    2014-01-01

    Background The aim of this study was to evaluate central corneal thickness in patients with atopic keratoconjunctivitis. Material/Methods The study was conducted in the Atatürk University School of Medicine between April 2011 and June 2013. The study group included 60 eyes of 30 patients with atopic keratoconjunctivitis. Sixty eyes of 30 healthy individuals without any ophthalmic or systemic pathology were used as a control group. The central corneal thickness was measured with ultrasonic pachymetry. Results In each group, all subjects included in the study had a best corrected visual acuity (BCVA) of 20/25 or better. In the study group past medical histories revealed eczema in 19 patients, asthma in 16, and atopic dermatitis in 15. During clinical examination cicatricial conjunctivitis was noted in 5 patients, giant papillae in 4, symblepharon in 2, and entropion in 2. The mean central corneal thickness was 523.45±18.03 μm in the study group (mean age: 37.05±5.7 years) and 540.30±38.91 μm in the control group (mean age: 36.55±7.1 years), and the difference was statistically significant (p<0.001). Conclusions Evaluation of corneal thickness is important in situations such as corneal refractive surgery and contact lens use, and is an essential parameter in a wide range of ocular disorders, including glaucoma and keratoconus. Therefore, ophthalmologists should be aware of the low central corneal thickness in patients with atopic keratoconjunctivitis. PMID:25240805

  18. Noncontact depth-resolved micro-scale corneal elastography

    NASA Astrophysics Data System (ADS)

    Wang, Shang; Larin, Kirill V.

    2015-03-01

    Noninvasive high-resolution depth-resolved measurement of corneal biomechanics is of great clinical significance for improving the diagnosis and optimizing the treatment of various degenerated ocular diseases. Here, we report a micro-scale optical coherence elastography (OCE) method that enables noncontact assessment of the depthwise elasticity distribution in the cornea. The OCE system combines a focused air-puff device with phase-sensitive optical coherence tomography (OCT). Low-pressure short-duration air stream is used to load the cornea with the localized displacement at micron level. The phase-resolved OCT detection with nano-scale sensitivity probes the induced corneal deformation at various locations within a scanning line, providing the ultra-fast imaging of the corneal lamb wave propagation. With spectral analysis, the amplitude spectra and the phase spectra are available for the estimation of the frequency range of the lamb wave and the quantification of the wave propagation, respectively. Curved propagation paths following the top and bottom corneal boundaries are selected inside the cornea for measuring the phase velocity of the lamb wave at the major frequency components over the whole depths. Our pilot experiments on ex vivo rabbit eyes indicate the distinct stiffness of different layers in the cornea, including the epithelium, the anterior stroma, the posterior stroma, and the innermost region, which demonstrates the feasibility of this micro-scale OCE method for noncontact depth-resolved corneal elastography. Also, the quantification of the lamb wave dispersion in the cornea could lead to the measurement of the elastic modulus, suggesting the potential of this method for quantitative monitoring of the corneal biomechanics.

  19. Measurement of corneal tangent modulus using ultrasound indentation.

    PubMed

    Wang, Li-Ke; Huang, Yan-Ping; Tian, Lei; Kee, Chea-Su; Zheng, Yong-Ping

    2016-09-01

    Biomechanical properties are potential information for the diagnosis of corneal pathologies. An ultrasound indentation probe consisting of a load cell and a miniature ultrasound transducer as indenter was developed to detect the force-indentation relationship of the cornea. The key idea was to utilize the ultrasound transducer to compress the cornea and to ultrasonically measure the corneal deformation with the eyeball overall displacement compensated. Twelve corneal silicone phantoms were fabricated with different stiffness for the validation of measurement with reference to an extension test. In addition, fifteen fresh porcine eyes were measured by the developed system in vitro. The tangent moduli of the corneal phantoms calculated using the ultrasound indentation data agreed well with the results from the tensile test of the corresponding phantom strips (R(2)=0.96). The mean tangent moduli of the porcine corneas measured by the proposed method were 0.089±0.026MPa at intraocular pressure (IOP) of 15mmHg and 0.220±0.053MPa at IOP of 30mmHg, respectively. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) of tangent modulus were 14.4% and 0.765 at 15mmHg, and 8.6% and 0.870 at 30mmHg, respectively. The preliminary study showed that ultrasound indentation could be applied to the measurement of corneal tangent modulus with good repeatability and improved measurement accuracy compared to conventional surface displacement-based measurement method. The ultrasound indentation can be a potential tool for the corneal biomechanical properties measurement in vivo.

  20. Effect of acacia honey on cultured rabbit corneal keratocytes

    PubMed Central

    2014-01-01

    Background Acacia honey is a natural product which has proven to have therapeutic effects on skin wound healing, but its potential healing effects in corneal wound healing have not been studied. This study aimed to explore the effects of Acacia honey (AH) on corneal keratocytes morphology, proliferative capacity, cell cycle, gene and protein analyses. Keratocytes from the corneal stroma of six New Zealand white rabbits were isolated and cultured until passage 1. The optimal dose of AH in the basal medium (FD) and medium containing serum (FDS) for keratocytes proliferation was identified using MTT assay. The morphological changes, gene and protein expressions of aldehyde dehydrogenase (ALDH), marker for quiescent keratocytes and vimentin, marker for fibroblasts were detected using q-RTPCR and immunocytochemistry respectively. Flowcytometry was performed to evaluate the cell cycle analysis of corneal keratocytes. Results Cultured keratocytes supplemented with AH showed no morphological changes compared to control. Keratocytes cultured in FD and FDS media supplemented with 0.025% AH showed optimal proliferative potential compared with FD and FDS media, respectively. Gene expressions of ADLH and vimentin were increased in keratocytes cultured with AH enriched media. All proteins were expressed in keratocytes cultured in all media in accordance to the gene expression findings. No chromosomal changes were detected in keratocytes in AH enriched media. Conclusion Corneal keratocytes cultured in media supplemented with 0.025% AH showed an increase in proliferative capacity while retaining their morphology, gene and protein expressions with normal cell cycle. The results of the present study show promising role of AH role in accelerating the initial stage of corneal wound healing. PMID:24885607

  1. Corneal topography matching by iterative registration.

    PubMed

    Wang, Junjie; Elsheikh, Ahmed; Davey, Pinakin G; Wang, Weizhuo; Bao, Fangjun; Mottershead, John E

    2014-11-01

    Videokeratography is used for the measurement of corneal topography in overlapping portions (or maps) which must later be joined together to form the overall topography of the cornea. The separate portions are measured from different viewpoints and therefore must be brought together by registration of measurement points in the regions of overlap. The central map is generally the most accurate, but all maps are measured with uncertainty that increases towards the periphery. It becomes the reference (or static) map, and the peripheral (or dynamic) maps must then be transformed by rotation and translation so that the overlapping portions are matched. The process known as registration, of determining the necessary transformation, is a well-understood procedure in image analysis and has been applied in several areas of science and engineering. In this article, direct search optimisation using the Nelder-Mead algorithm and several variants of the iterative closest/corresponding point routine are explained and applied to simulated and real clinical data. The measurement points on the static and dynamic maps are generally different so that it becomes necessary to interpolate, which is done using a truncated series of Zernike polynomials. The point-to-plane iterative closest/corresponding point variant has the advantage of releasing certain optimisation constraints that lead to persistent registration and alignment errors when other approaches are used. The point-to-plane iterative closest/corresponding point routine is found to be robust to measurement noise, insensitive to starting values of the transformation parameters and produces high-quality results when using real clinical data.

  2. Tear film MMP accumulation and corneal disease

    PubMed Central

    Smith, V; Rishmawi, H; Hussein, H; Easty, D

    2001-01-01

    BACKGROUND/AIMS—Matrix metalloproteinases (MMPs) accumulate in the tears of patients with active peripheral ulcerative keratitis (PUK) but it is unknown whether these enzymes have a central role in disease progression. The aims of the present investigation were to determine the source of these enzymes and to ascertain whether their accumulation in tears is a phenomenon specific to PUK or a general feature of other anterior segment diseases.
METHODS—The experimental samples were obtained from the culture media of conjunctival and corneal epithelial cells, from fractionated blood plasma and leucocytes of healthy subjects and patients with rheumatoid arthritis, and from the tears of healthy subjects and patients with a variety of anterior segment diseases. The MMPs of all samples were visualised by zymography and tear samples were assayed using nitrophenol acetate and an MMP-9 susceptible quenched fluorescent peptide as substrate.
RESULTS—The major MMPs that accumulate in the tears of patients with rheumatoid arthritis with active ocular disease are MMP-9 and a species of Mr 116 000. By comparing the zymographic activity profiles of the gelatinases present in the samples obtained, it was deduced that the main source of these MMPs was granulocytes. Their accumulation in tears was not unique to patients with PUK; detectable amounts of the enzymes also occurred in the tears of patients with keratoconus with associated atopic disease, patients undergoing treatment for herpetic eye disease, and patients with systemic and non-systemic dry eye disease.
CONCLUSION—The MMPs that accumulate in tears are mainly derived from granulocytes. This may be effected by autoimmune diseases that involve ocular tissue or by ocular diseases that induce an inflammatory response.

 PMID:11159476

  3. Corneal edema induced by cold in trigeminal nerve palsy

    SciTech Connect

    Thorgaard, G.L.; Holland, E.J.; Krachmer, J.H.

    1987-05-15

    We examined a 34-year-old man who complained of decreased visual acuity in the right eye when exposed to cold environmental temperatures. Although examination at room temperature was unremarkable, he developed prominent unilateral corneal edema of the right eye when placed in a cold room at 4 C. Corneal thickness increased from 525 to 789 microns in the affected eye. Further examination disclosed a right-sided trigeminal nerve palsy. He was eventually found to have a 3 X 2-cm tentorial ridge meningioma on the right.

  4. Noninvasive spectroscopic diagnosis of superficial ocular lesions and corneal infections

    SciTech Connect

    Mourant, J.R.; Bigio, I.J.; Johnson, T.; Shimada, T.; Gritz, D.C.; Storey-Held, K.

    1994-02-01

    The potential of a rapid noninvasive diagnostic system to detect tissue abnormalities on the surface of the eye has been investigated. The optical scatter signal from lesions and normal areas on the conjunctival sclera of the human eye were measured in vivo. It is possible to distinguish nonpigmented pingueculas from other lesions. The ability of the system to detect malignancies could not be tested because none of the measured and biopsied lesions were malignant. Optical scatter and fluorescence spectra of bacterial and fungal suspensions, and corneal irritations were also collected. Both scattering and fluorescence show potential for diagnosing corneal infections.

  5. Noninvasive evaluation of corneal abnormalities using static and dynamic light scattering

    NASA Astrophysics Data System (ADS)

    Ansari, Rafat R.; Misra, Anup K.; Leung, Alfred B.; King, James F.; Datiles, Manuel B., III

    2002-06-01

    A preliminary study of corneal abnormalities in intact bovine eyes is presented. Twenty-one eyes were treated with chemicals, cotton swabs, and radial and photo-refractive surgeries. Dynamic and static light scattering was performed as a function of the penetration depth into the corneal tissue. Topographical maps of corneal refractive power from untreated and treated corneas were also obtained using videokeratoscopy and results compared. The ultimate aim is to develop the technique of dynamic light scattering (DLS) for clinical applications in early evaluation of corneal complications after laser-assisted in situ keratomileusis (LASIK) surgeries and other corneal abnormalities.

  6. Determining the zone of reflection for posterior corneal surface comparison phakometry.

    PubMed

    Carkeet, Andrew

    2009-01-01

    Although comparison phakometry has been used by a number of studies to measure posterior corneal shape, these studies have not calculated the size of the posterior corneal zones of reflection they assessed. This paper develops paraxial equations for calculating posterior corneal zones of reflection, based on standard keratometry equations and equivalent mirror theory. For targets used in previous studies, posterior corneal reflection zone sizes were calculated using paraxial equations and using exact ray tracing, assuming spherical and aspheric corneal surfaces. Paraxial methods and exact ray tracing methods give similar estimates for reflection zone sizes less than 2 mm, but for larger zone sizes ray tracing methods should be used.

  7. Non-Invasive Evaluation of Corneal Abnormalities Using Static and Dynamic Light Scattering

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; Misra, Anup K.; Leung, Alfred B.; King, James F.; Datiles, Manuel B., III

    2002-01-01

    A preliminary study of corneal abnormalities in intact bovine eyes is presented. Twenty-one eyes were treated with chemicals, cotton swabs, and radial and photo-refractive surgeries. Dynamic and static light scattering was performed as a function of the penetration depth into the corneal tissue. Topographical maps of corneal refractive power from untreated and treated corneas were also obtained using videokeratoscopy and results compared. The ultimate aim is to develop the technique of dynamic light scattering (DLS) for clinical applications in early evaluation of corneal complications after laser-assisted in situ keratomileusis (LASIK) surgeries and other corneal abnormalities.

  8. Corneal sensitivity and correlations between decreased sensitivity and anterior segment pathology in ocular leprosy.

    PubMed

    Karaçorlu, M A; Cakiner, T; Saylan, T

    1991-02-01

    Leprosy is one of the leading causes of corneal hyposensitivity. In this article the corneal sensitivity of 143 leprosy patients was examined, and correlations between corneal hyposensitivity and anterior segment pathology were detected. Twenty four healthy volunteers were examined as controls. Various degrees of corneal loss of sensitivity were found in 46.2% of leprosy patients. Lagophthalmos, chronic lepromatous granulomatous uveitis, iris atrophy, and social blindness were found 4.5-16.6 times more frequently in eyes which developed severe corneal hyposensitivity.

  9. Corneal sensitivity and correlations between decreased sensitivity and anterior segment pathology in ocular leprosy.

    PubMed Central

    Karaçorlu, M A; Cakiner, T; Saylan, T

    1991-01-01

    Leprosy is one of the leading causes of corneal hyposensitivity. In this article the corneal sensitivity of 143 leprosy patients was examined, and correlations between corneal hyposensitivity and anterior segment pathology were detected. Twenty four healthy volunteers were examined as controls. Various degrees of corneal loss of sensitivity were found in 46.2% of leprosy patients. Lagophthalmos, chronic lepromatous granulomatous uveitis, iris atrophy, and social blindness were found 4.5-16.6 times more frequently in eyes which developed severe corneal hyposensitivity. PMID:1995039

  10. High-Risk Corneal Graft Rejection in the Setting of Previous Corneal Herpes Simplex Virus (HSV)-1 Infection

    PubMed Central

    Kuffova, Lucia; Knickelbein, Jared E.; Yu, Tian; Medina, Carlos; Amescua, Guillermo; Rowe, Alexander M.; Hendricks, Robert L.; Forrester, John V.

    2016-01-01

    Purpose The “high-risk phenotype” of corneal graft recipients is considered to be related to preexisting vascularization such as that associated with herpes simplex virus-1 (HSV-1) keratitis (HSK). The purpose of this study was to investigate the immunologic mechanisms underlying accelerated corneal graft rejection using a mouse model of HSK. Methods Herpes simplex virus type 1 keratitis was induced in BALB/c mice. Syngeneic and allogeneic (C57BL/6 mice) corneal grafts were performed in mice with HSK at different times after infection. Some grafts were performed on HSV-infected CD4 T cell–deficient BALB/c mice. Clinical, histologic, immunologic, and virus detection studies were performed on samples of cornea, draining lymph node (LN), and trigeminal ganglion (TG) cells. Results Corneal grafts in mice with HSK rejected with higher frequency and more rapid tempo compared with grafts in uninfected mice. In corneas with HSK and vascularization at the time of grafting, both syngeneic and allogeneic corneal grafts failed with similar frequency and tempo. However, in the absence of preexisting inflammation and vascularization, syngeneic grafts were accepted when the grafts were performed at a late time point after HSV infection (42 days), whereas allografts were rejected at this time. In contrast, syngeneic grafts in nonvascularized HSV-infected recipients failed if they were performed within 10 days of HSV infection, an effect that was dependent on CD4 T cells, as demonstrated using CD4 deficient mice. Importantly, a variably sustained but strongly positive anti-HSV T-cell response was detected in allografted HSK recipients with a similar but lesser response in syngeneic hosts. Conclusions A previous HSV-1 corneal infection predisposes donor grafts to a high risk of failure by both innate and adaptive immune mechanisms in which an anti-HSV CD4 T-cell response plays a prominent role. PMID:27050878

  11. Proteomic analysis of the soluble fraction from human corneal fibroblasts with reference to ocular transparency.

    PubMed

    Karring, Henrik; Thøgersen, Ida B; Klintworth, Gordon K; Enghild, Jan J; Møller-Pedersen, Torben

    2004-07-01

    The transparent corneal stroma contains a population of corneal fibroblasts termed keratocytes, which are interspersed between the collagen lamellae. Under normal conditions, the keratocytes are quiescent and transparent. However, after corneal injury the keratocytes become activated and transform into backscattering wound-healing fibroblasts resulting in corneal opacification. At present, the most popular hypothesis suggests that particular abundant water-soluble proteins called enzyme-crystallins are involved in maintaining corneal cellular transparency. Specifically, corneal haze development is thought to be related to low levels of cytoplasmic enzyme-crystallins in reflective corneal fibroblasts. To further investigate this hypothesis, we have used a proteomic approach to identify the most abundant water-soluble proteins in serum-cultured human corneal fibroblasts that represent an in vitro model of the reflective wound-healing keratocyte phenotype. Densitometry of one-dimensional gels revealed that no single protein isoform exceeded 5% of the total water-soluble protein fraction, which is the qualifying property of a corneal enzyme-crystallin according to the current definition. This result indicates that wound-healing corneal fibroblasts do not contain enzyme-crystallins. A total of 254 protein identifications from two-dimensional gels were performed representing 118 distinct proteins. Proteins protecting against oxidative stress and protein misfolding were prominent, suggesting that these processes may participate in the generation of cytoplasmic light-scattering from corneal fibroblasts.

  12. Targeted AAV5-Smad7 gene therapy inhibits corneal scarring in vivo

    PubMed Central

    Gupta, Suneel; Rodier, Jason T.; Sharma, Ajay; Giuliano, Elizabeth A.; Sinha, Prashant R.; Hesemann, Nathan P.; Ghosh, Arkasubhra; Mohan, Rajiv R.

    2017-01-01

    Corneal scarring is due to aberrant activity of the transforming growth factor β (TGFβ) signaling pathway following traumatic, mechanical, infectious, or surgical injury. Altered TGFβ signaling cascade leads to downstream Smad (Suppressor of mothers against decapentaplegic) protein-mediated signaling events that regulate expression of extracellular matrix and myogenic proteins. These events lead to transdifferentiation of keratocytes into myofibroblasts through fibroblasts and often results in permanent corneal scarring. Hence, therapeutic targets that reduce transdifferentiation of fibroblasts into myofibroblasts may provide a clinically relevant approach to treat corneal fibrosis and improve long-term visual outcomes. Smad7 protein regulates the functional effects of TGFβ signaling during corneal wound healing. We tested that targeted delivery of Smad7 using recombinant adeno-associated virus serotype 5 (AAV5-Smad7) delivered to the corneal stroma can inhibit corneal haze post photorefractive keratectomy (PRK) in vivo in a rabbit corneal injury model. We demonstrate that a single topical application of AAV5-Smad7 in rabbit cornea post-PRK led to a significant decrease in corneal haze and corneal fibrosis. Further, histopathology revealed lack of immune cell infiltration following AAV5-Smad7 gene transfer into the corneal stroma. Our data demonstrates that AAV5-Smad7 gene therapy is relatively safe with significant potential for the treatment of corneal disease currently resulting in fibrosis and impaired vision. PMID:28339457

  13. Corneal Viscoelastic Properties from Finite-Element Analysis of In Vivo Air-Puff Deformation

    PubMed Central

    Kling, Sabine; Bekesi, Nandor; Dorronsoro, Carlos; Pascual, Daniel; Marcos, Susana

    2014-01-01

    Biomechanical properties are an excellent health marker of biological tissues, however they are challenging to be measured in-vivo. Non-invasive approaches to assess tissue biomechanics have been suggested, but there is a clear need for more accurate techniques for diagnosis, surgical guidance and treatment evaluation. Recently air-puff systems have been developed to study the dynamic tissue response, nevertheless the experimental geometrical observations lack from an analysis that addresses specifically the inherent dynamic properties. In this study a viscoelastic finite element model was built that predicts the experimental corneal deformation response to an air-puff for different conditions. A sensitivity analysis reveals significant contributions to corneal deformation of intraocular pressure and corneal thickness, besides corneal biomechanical properties. The results show the capability of dynamic imaging to reveal inherent biomechanical properties in vivo. Estimates of corneal biomechanical parameters will contribute to the basic understanding of corneal structure, shape and integrity and increase the predictability of corneal surgery. PMID:25121496

  14. Human Corneal Endothelial Cells Expanded In Vitro Are a Powerful Resource for Tissue Engineering

    PubMed Central

    Liu, Yongsong; Sun, Hong; Hu, Min; Zhu, Min; Tighe, Sean; Chen, Shuangling; Zhang, Yuan; Su, Chenwei; Cai, Subo; Guo, Ping

    2017-01-01

    Human corneal endothelial cells have two major functions: barrier function mediated by proteins such as ZO-1 and pump function mediated by Na-K-ATPase which help to maintain visual function. However, human corneal endothelial cells are notorious for their limited proliferative capability in vivo and are therefore prone to corneal endothelial dysfunction that eventually may lead to blindness. At present, the only method to cure corneal endothelial dysfunction is by transplantation of a cadaver donor cornea with normal corneal endothelial cells. Due to the global shortage of donor corneas, it is vital to engineer corneal tissue in vitro that could potentially be transplanted clinically. In this review, we summarize the advances in understanding the behavior of human corneal endothelial cells, their current engineering strategy in vitro and their potential applications. PMID:28260988

  15. Corneal collagen cross-linking and liposomal amphotericin B combination therapy for fungal keratitis in rabbits

    PubMed Central

    Hao, Zhao-Qin; Song, Jin-Xin; Pan, Shi-Yin; Zhang, Lin; Cheng, Yan; Liu, Xian-Ning; Wu, Jie; Xiao, Xiang-Hua; Gao, Wei; Zhu, Hai-Feng

    2016-01-01

    AIM To observe the therapeutic effect of corneal collagen cross-linking (CXL) in combination with liposomal amphotericin B in fungal corneal ulcers. METHODS New Zealand rabbits were induced fungal corneal ulcers by scratching and randomly divided into 3 groups, i.e. control, treated with CXL, and combined therapy of CXL with 0.25% liposomal amphotericin B (n=5 each). The corneal lesions were documented with slit-lamp and confocal microscopy on 3, 7, 14, 21 and 28d after treatment. The corneas were examined with transmission electron microscopy (TEM) at 4wk. RESULTS A rabbit corneal ulcer model of Fusarium was successfully established. The corneal epithelium defect areas in the two treatment groups were smaller than that in the control group on 3, 7, 14 and 21d (P<0.05). The corneal epithelium defect areas of the combined group was smaller than that of the CXL group (P<0.05) on 7 and 14d, but there were no statistical differences on 3, 21 and 28d. The corneal epithelium defects of the two treatment groups have been healed by day 21. The corneal epithelium defects of the control group were healed on 28d. The diameters of the corneal collagen fiber bundles (42.960±7.383 nm in the CXL group and 37.040±4.160 nm in the combined group) were thicker than that of the control group (24.900±1.868 nm), but there was no difference between the two treatment groups. Some corneal collagen fiber bundles were distorted and with irregular arrangement, a large number of fibroblasts could be seen among them but no inflammatory cells in both treatment groups. CONCLUSION CXL combined with liposomal amphotericin B have beneficial effects on fungal corneal ulcers. The combined therapy could alleviate corneal inflammattions, accelerate corneal repair, and shorten the course of disease. PMID:27990355

  16. Exposure Stress Induces Reversible Corneal Graft Opacity in Recipients With Herpes Simplex Virus-1 Infections

    PubMed Central

    Rowe, Alexander M.; Yun, Hongmin; Hendricks, Robert L.

    2017-01-01

    Purpose Most of the inflammation in murine herpes simplex virus type 1 (HSV-1)-induced stromal keratitis (HSK) is due to exposure stress resulting from loss of corneal nerves and blink reflex. Corneal grafts often fail when placed on corneal beds with a history of HSK. We asked if corneal exposure contributes to the severe pathology of corneal grafts on HSV-1–infected corneal beds. Methods Herpes simplex virus type 1–infected corneas were tested for blink reflex. Opacity and vascularization were monitored in allogeneic and syngeneic corneal grafts that were transplanted to corneal beds with no blink reflex or to those that retained blink reflex in at least one quadrant following infection. Results Retention of any level of blink reflex significantly reduced inflammation in HSV-1–infected corneas. Corneal allografts placed on HSV-1–infected beds lacking corneal blink reflex developed opacity faster and more frequently than those placed on infected beds that partially or completely retained blink reflex. Corneal grafts placed on infected corneal beds with no blink reflex rapidly became opaque to a level that would be considered rejection. However, protecting these grafts from exposure by tarsorrhaphy prevented or reversed the opacity in both syngeneic and allogenic grafts. Conclusions Exposure due to HSV-1–engendered hypoesthesia causes rapid, severe, persistent, but reversible opacification of both allogeneic and syngeneic corneal grafts. This opacity should not be interpreted as immunologic rejection. Exposure stress may contribute to the high rate of corneal graft pathology in patients with recurrent HSK. PMID:28055100

  17. Techniques for application of tissue adhesive for corneal perforations.

    PubMed

    Erdey, R A; Lindahl, K J; Temnycky, G O; Aquavella, J V

    1991-06-01

    We describe a modified technique of using cyanoacrylate adhesive to seal corneal perforations. Easily performed at the slit lamp, its advantages over previously described methods include a smooth, contoured collagen surface overlying the adhesive, which is easily wet by the tear film. Even greater comfort and protection are provided by the addition of a hydrophilic bandage lens or collagen shield.

  18. Rapid, automated mosaicking of the human corneal subbasal nerve plexus.

    PubMed

    Vaishnav, Yash J; Rucker, Stuart A; Saharia, Keshav; McNamara, Nancy A

    2017-03-04

    Corneal confocal microscopy (CCM) is an in vivo technique used to study corneal nerve morphology. The largest proportion of nerves innervating the cornea lie within the subbasal nerve plexus, where their morphology is altered by refractive surgery, diabetes and dry eye. The main limitations to clinical use of CCM as a diagnostic tool are the small field of view of CCM images and the lengthy time needed to quantify nerves in collected images. Here, we present a novel, rapid, fully automated technique to mosaic individual CCM images into wide-field maps of corneal nerves. We implemented an OpenCV image stitcher that accounts for corneal deformation and uses feature detection to stitch CCM images into a montage. The method takes 3-5 min to process and stitch 40-100 frames on an Amazon EC2 Micro instance. The speed, automation and ease of use conferred by this technique is the first step toward point of care evaluation of wide-field subbasal plexus (SBP) maps in a clinical setting.

  19. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Corneal radius measuring device. 886.1450 Section 886.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... chapter, subject to the limitations in § 886.9, only when the device does not include computer software...

  20. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Corneal radius measuring device. 886.1450 Section 886.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... chapter, subject to the limitations in § 886.9, only when the device does not include computer software...

  1. New insight into non-healing corneal ulcers: iatrogenic crystals

    PubMed Central

    Livingstone, I; Stefanowicz, F; Moggach, S; Connolly, J; Ramamurthi, S; Mantry, S; Ramaesh, K

    2013-01-01

    Aims To characterise and correlate crystalline precipitations implicated in non-healing corneal ulceration in two patients with a previous history of acanthamoeba keratitis. Materials and methods Persistence of acanthamoeba and secondary bacterial infection was excluded with negative corneal scrapes. Confocal microscopy identified crystal-like deposits within the corneal stroma. To investigate possible precipitating combinations, all concurrent treatments at the time of presentation were mixed in wells, with observation of precipitate formation. Precipitates were observed with phase-contrast microscopy, and subsequently characterised via crystallography techniques and electrospray ionisation mass spectrometry. Results Combinations of dexamethasone 0.1% minims and chlorhexidine gluconate 0.2% formed an amorphous material characterised by electrospray ionisation mass spectrometry as an insoluble chlorhexidine salt. Combinations of chloramphenicol drops and timolol 0.5% formed a crystal identified via X-ray crystallography as santite (K(B5O6(OH)4).(H2O)2). This is a borate mineral identified in nature, arising from thermal springs, but never reported in biological tissues. Clinical improvement was observed following the cessation of the implicated precipitating combinations. Conclusion Our observations suggest iatrogenic precipitate formation, with a potential deleterious effect upon healing. The substrates for these precipitates include several frequently prescribed topical ophthalmic treatments. These findings shed new light on the aetiopathogenesis of non-healing corneal ulceration, and have broad implications on topical prescribing for this challenging condition. PMID:23558213

  2. Identification of Phosphorylation Sites on Extracellular Corneal Epithelial Cell Maspin

    PubMed Central

    Narayan, Malathi; Mirza, Shama P.; Twining, Sally S.

    2011-01-01

    Maspin, a 42-kDa non classical serine protease inhibitor (serpin) is expressed by epithelial cells of various tissues including the cornea. The protein localizes to the nucleus and cytosol, and is present in the extracellular space. While extracellular maspin regulates corneal stromal fibroblast adhesion and inhibits angiogenesis during wound healing in the cornea, the molecular mechanism of its extracellular functions is unclear. We hypothesized that identifying post-translational modifications of maspin, such as phosphorylation, may help decipher its mode of action. The focus of this study was on the identification of phosphorylation sites on extracellular maspin, since the extracellular form of the molecule is implicated in several functions. Multi-stage fragmentation mass spectrometry was used to identify sites of phosphorylation on extracellular corneal epithelial cell maspin. A total of eight serine and threonine phosphorylation sites (Thr50, Ser97, Thr118, Thr157, Ser240, Ser298, Thr310, Ser316) were identified on the extracellular forms of the molecule. Phosphorylation of tyrosine residues on extracellular maspin was not detected on extracellular maspin from corneal epithelial cell, in contrast to breast epithelial cells. This study provides the basis for further investigation into the functional role of phosphorylation of corneal epithelial maspin. PMID:21365746

  3. Variations in the corneal surface temperature with contact lens wear.

    PubMed

    Ooi, E H; Ng, E Y K; Purslow, C; Acharya, R

    2007-05-01

    This paper presents the two-dimensional simulation of heat propagation in the human eye model during contact lens wear with finite element analysis. Three types of contact lens are studied: Lotrafilcon A, Balafilcon A, and Etafilcon A. The models are solved for both steady and transient solutions. The corneal surface temperature during contact lens wear is found to decrease (average, 0.52 +/- 0.05 degrees C compared with a bare cornea for all lens types). A contact lens with a higher water content has a lower steady state temperature than a contact lens with a lower water content does. Various initial temperatures for the contact lens are found to affect the first 400 s of the temperature variation. When the initial temperature is lower than the corneal temperature, a reduction in temperature is observed during contact lens insertion while the opposite is observed when the initial temperature is higher than the corneal temperature. The increase in evaporation rate when a contact lens is worn increases the cooling effect on the ocular surface. This is suggested to be the cause of lower corneal surface temperature when wearing a contact lens.

  4. Calculation of corneal temperature and shrikage during laser thermokeratoplasty (LTK)

    NASA Astrophysics Data System (ADS)

    Manns, Fabrice; Borja, David; Parel, Jean-Marie A.

    2002-06-01

    Purpose. The purpose of this study was to develop a model to predict the corneal temperature and shrinkage during laser thermokeratoplasty and other clinical procedures relying on laser-induced thermal shrinkage of collagenous tissue. Methods. The corneal temperature was calculated by solving the bio-heat equation during laser irradiation using a semi-analytical technique. To calculate shrinkage, we assumed that corneal thermal shrinkage is a thermal denaturation process that follows an Arrhenius equation, and that shrinkage resulting from denaturation is proportional to the amount of thermal damage. We calculated shrinkage for pulsed Ho:YAG laser thermokeratoplasty using the clinical treatment algorithm. Results. The thermal model predicts that the corneal temperature reaches values that may be high enough to induce surface vaporization of the epithelium and thermal damage of the endothelium. Shrinkage calculations show that significant shrinkage is produced only after the third laser pulse. Shrinkage is produced mainly during laser pulses and stops shortly after the start of the cooling phase between laser pulses. Conclusions. These calculations demonstrate that thermal shrinkage can be predicted by combining an optical-thermal model and a thermal denaturation model. Accurate quantitative prediction of the shrinkage effect requires a better knowledge of the dynamics of shrinkage and of the optical thermal response of the cornea.

  5. Non-mulberry Silk Fibroin Biomaterial for Corneal Regeneration

    PubMed Central

    Hazra, Sarbani; Nandi, Sudip; Naskar, Deboki; Guha, Rajdeep; Chowdhury, Sushovan; Pradhan, Nirparaj; Kundu, Subhas C.; Konar, Aditya

    2016-01-01

    Purpose: Successful repair of a damaged corneal surface is a great challenge and may require the use of a scaffold that supports cell growth and differentiation. Amniotic membrane is currently used for this purpose, in spite of its limitations. A thin transparent silk fibroin film from non-mulberry Antheraea mylitta (Am) has been developed which offers to be a promising alternative. The silk scaffolds provide sufficient rigidity for easy handling, the scaffolds support the sprouting, migration, attachment and growth of epithelial cells and keratocytes from rat corneal explants; the cells form a cell sheet, preserve their phenotypes, express cytokeratin3 and vimentin respectively. The films also support growth of limbal stem cell evidenced by expression of ABCG2. The cell growth on the silk film and the amniotic membrane is comparable. The implanted film within the rabbit cornea remains transparent, stable. The clinical examination as well as histology shows absence of any inflammatory response or neovascularization. The corneal surface integrity is maintained; tear formation, intraocular pressure and electroretinography of implanted eyes show no adverse changes. The silk fibroin film from non-mulberry silk worms may be a worthy candidate for use as a corneal scaffold. PMID:26908015

  6. Preliminary results of a computerized Placido disk surgical corneal topographer

    NASA Astrophysics Data System (ADS)

    Carvalho, Luis A.; Tonissi, S. A.; Castro, Jarbas C.

    1999-06-01

    We have developed a novel instrument for computerized corneal topography during surgery. The instrument measures a region of approximately 7 mm in diameter, providing the surgeon with precise values of power and astigmatism. The system is based on a Placido Disc projecting system, which is attached to the objective lens of the surgical microscope. The Placido Disc pattern is reflected by a 50% beam splitter attached to the body of the microscope. At the beam splitter we installed our home-made adaptor and a CCD monochromatic high resolution camera. A high quality frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Algorithms based on image processing techniques were implemented for edge detection of pattern. Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points were calculated for each exam. Preliminary measurements on 10 healthy corneas were compared with the measurements made on an EyeSys Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for power and 5 degrees for cylinder. This system, with some improvements, may be successfully used to diminish high post surgical astigmatisms in surgeries such as cataract and corneal transplant. This system could also be used to gather preoperative data in corneal topography assisted LASIK.

  7. Scattering properties and transparency characterization of human corneal grafts

    NASA Astrophysics Data System (ADS)

    Casadessus, Olivier; Georges, Ga"lle; Siozade-Lamoine, Laure; Deumié, Carole; Conrath, John; Hoffart, Louis

    2011-06-01

    The cornea is the single human tissue being transparent. This unique property may be explained by the particular structure of the cornea, but the precise role of each of its constituents remains unsolved. On other matter, prior to corneal transplant, graft must be evaluated during a sorting procedure where a technician assesses of its transparency quality. Nevertheless, this criterion remains subjective and qualitative. This study proposes to combine 3D imagery using Full-Field Optical Coherence Tomography jointly with angular resolved scattering measurement to achieve a quantitative transparency characterization of the cornea. The OCT provides micrometric resolution structural information about the cornea, and we observe the evolution occurring when oedema develops within the tissue. Scattering properties are evaluated and compared parallely, as the transparency of the graft. A close link between the scattering intensity level of the cornea and its thickness is highlighted through this study. Furthermore, the three-dimensional imagery offers a view over the structural modifications leading to a change in transparency, and the combination with scattering properties measurement provides clues over the characteristic scale of scatterers to consider for a better understanding of corneal transparency evolution. Achieving an objective and quantified parameter for the transparency would be helpful for a more efficient corneal graft sorting, and may be able to detect the presence of localized wounds as the ones related to a previous refractive surgery. However, the study of graft nearly eligible for corneal transplant would be needed to confirm the results this study presents.

  8. Gene Therapy and Gene Editing for the Corneal Dystrophies.

    PubMed

    Williams, Keryn A; Irani, Yazad D

    2016-01-01

    Despite ever-increasing understanding of the genetic underpinnings of many corneal dystrophies, gene therapy designed to ameliorate disease has not yet been reported in any human patient. In this review, we explore the likely reasons for this apparent failure of translation. We identify the requirements for success: the genetic defect involved must have been identified and mapped, vision in the affected patient must be significantly impaired or likely to be impaired, no better or equivalently effective treatment must be available, the treatment must be capable of modulating corneal pathology, and delivery of the construct to the appropriate cell must be practicable. We consider which of the corneal dystrophies might be amenable to treatment by genetic manipulations, summarize existing therapeutic options for treatment, and explore gene editing using clustered regularly interspaced short palindromic repeat/Cas and other similar transformative technologies as the way of the future. We then summarize recent laboratory-based advances in gene delivery and the development of in vitro and in vivo models of the corneal dystrophies. Finally, we review recent experimental work that has increased our knowledge of the pathobiology of these conditions.

  9. Nerve regeneration by human corneal stromal keratocytes and stromal fibroblasts

    PubMed Central

    Yam, Gary Hin-Fai; Williams, Geraint P.; Setiawan, Melina; Yusoff, Nur Zahirah Binte M.; Lee, Xiao-wen; Htoon, Hla Myint; Zhou, Lei; Fuest, Matthias; Mehta, Jodhbir S.

    2017-01-01

    Laser refractive surgeries reshape corneal stroma to correct refractive errors, but unavoidably affect corneal nerves. Slow nerve regeneration and atypical neurite morphology cause desensitization and neuro-epitheliopathy. Following injury, surviving corneal stromal keratocytes (CSKs) are activated to stromal fibroblasts (SFs). How these two different cell types influence nerve regeneration is elusive. Our study evaluated the neuro-regulatory effects of human SFs versus CSKs derived from the same corneal stroma using an in vitro chick dorsal root ganglion model. The neurite growth was assessed by a validated concentric circle intersection count method. Serum-free conditioned media (CM) from SFs promoted neurite growth dose-dependently, compared to that from CSKs. We detected neurotrophic and pro-inflammatory factors (interleukin-8, interleukin-15, monocyte chemoattractant protein-1, eotaxin, RANTES) in SFCM by Bio-Plex Human Cytokine assay. More than 130 proteins in SFCM and 49 in CSKCM were identified by nanoLC-MS/MS. Proteins uniquely present in SFCM had reported neuro-regulatory activities and were predicted to regulate neurogenesis, focal adhesion and wound healing. Conclusively, this was the first study showing a physiological relationship between nerve growth and the metabolically active SFs versus quiescent CSKs from the same cornea source. The dose-dependent effect on neurite growth indicated that nerve regeneration could be influenced by SF density. PMID:28349952

  10. Proteins of the corneal stroma: importance in visual function.

    PubMed

    Xuan, Meng; Wang, Shurong; Liu, Xin; He, Yuxi; Li, Ying; Zhang, Yan

    2016-04-01

    The human cornea, consisting of five layers, is the transparent tissue that refracts and transmits light to the lens and retina, providing about two thirds of the refractive power of the eye. The stroma layer comprises nearly 90 % of the thickness of the cornea and thus plays a pivotal role in normal visual function. The bulk of this layer is constituted by proteins in the extracellular martrix secreted by the corneal epithelial, stroma, and endothelial cells. Clinical research has shown that corneal stroma diseases are common and involve conditions such as infections, injuries, and genetic defects, which cause severe visual disturbances or even blindness. To improve our understanding of the basic molecular mechanisms involved in the physiological and pathological activities of the corneal stroma, its proteins have been brought into the limelight to determine their crucial and irreplaceable roles. The data presented in a previous study have demonstrated the presence of 1679 proteins in the stroma, and this data set has subsequently been perfected by utilizing a highly sensitive isobaric peptide-labeling approach. According to their manifestations, these proteins can be classified as a gel-like organic material composed of proteoglycans, enzymes, and hemocyanin-binding proteins and a network of filaments composed of collagen, elastin, keratin, vimentin, and interconnected filaments comprising fibronectin and laminin. The aim of this review is to describe some corneal stroma proteins by highlighting their major functions and valuable applications in ophthalmologic research toward the better characterization and treatment of eye diseases.

  11. Cytochrome P450 arachidonic acid metabolism in bovine corneal epithelium

    SciTech Connect

    Masferrer, J.; Schwartzman, M.L.; Abraham, N.G.; Dunn, M.W.; McGiff, J.C.

    1986-03-01

    The presence of the cytochrom P450 system and its involvement in the metabolism of AA was studied in the corneal epithelium. This tissue contains cytochrome P450 as assessed directly by measurement of the carbon monoxide reduced spectrum (specific activity of 161 pmol/10 mg protein) and indirectly by measuring the activity of aryl hydrocarbon hydroxylase (AHH) - a cytochrome P450-dependent enzyme (11-39 pmol 3-OH benzopyrene/mg protein/10 min). When corneal epithelial microsomes were incubated with /sup 14/C-arachidonic acid, 30-50% of the total radioactivity was converted to two peaks, I and II. Further separation using high performance liquid chromatography has shown that each peak contains two metabolites, A,B and C,D. Metabolite formation was dependent on the addition of NADPH (1 mM) and inhibited by carbon monoxide and SKF-525A (100 ..mu..M) suggesting a cytochrome P450-dependent mechanism. Compound C (5-10 ..mu..M) inhibited the activity of corneal epithelial Na-K-ATPase by 30-60%, being 100-fold more potent than ouabain. Compound D (10-100 ng) induced a dose dependent relaxation of the rat caudal artery. Compound D also inhibited corneal Na-K-ATPase activity but less potently than compound C. These compounds may be important to transport processes of ocular epithelia and participate in the control of the ocular circulation and aqueous humor dynamics.

  12. Monitoring corneal hydration with a mid-infrared (IR) laser.

    PubMed

    Joshi, Abhijeet; Bennett, David B; Stafsudd, Oscar M

    2015-01-01

    A mid-infrared (IR) source at ∼ 3 μm radiation is used as a probe to measure hydration in porcine cornea. Since the Er(3+):YAG emission targets vibrational modes (around 3300 cm(-1)) in the H2O molecule, it is highly sensitive to changes in water content in the first ∼ 10 μm of the corneal tissue.

  13. Corneal topography: a review of terms and concepts.

    PubMed

    Roberts, C

    1996-06-01

    The American National Standards Institute in the United States is developing standards for the corneal topography industry with the help of manufacturers and the scientific community. This effort will help alleviate some of the inconsistencies in the industry. Until the results are reported, clinical users of the devices must sort through the information presented.

  14. Effect of tissue fit on corneal shape after transplantation.

    PubMed

    Cohen, K L; Tripoli, N K; Pellom, A C; Kupper, L L; Fryczkowski, A W

    1984-10-01

    Postkeratoplasty astigmatism is now a major problem preventing visual recovery. Certain postoperative topographic characteristics are felt to be dictated by the fit of the donor corneal button in its recipient bed. Deficient tissue at the wound is predicted to contribute to the location of the steep meridian and excess tissue to the location of the flat meridian. In an eight-cat sample using our Fit Assessment Method and Photogrammetric Index Method, the authors tested the relationship between button fit in recipient bed and resulting corneal curvature at approximately 42, 161, and 289 postoperative days. Corneal symmetry improved between the first and second postoperative periods. Deficient tissue led to steepened curvature and ample tissue to flattened curvature in the first measurement period. When buttons fit poorly, deficient tissue led to steepness in the first postoperative period, but led to flattened curvature 90 deg away from the deficient tissue meridian in the second and third periods. The relationship between ample tissue and flattest postoperative curvature did not depend on the magnitude of button-fed disparity in any period. Corneal elasticity appeared to influence the way tissue disparity affected postoperative topography. Our findings support Troutman's balloon mode. When there was a large amount of uncompensated tissue disparity, the tissue deficiency exerted a force that shortened the translimbal chord. This produced both steepened curvature parallel to this chord soon after surgery and flattened curvature at 90 deg to the chord in the stable postoperative cornea.

  15. Novel Identity and Functional Markers for Human Corneal Endothelial Cells

    PubMed Central

    Bartakova, Alena; Alvarez-Delfin, Karen; Weisman, Alejandra D.; Salero, Enrique; Raffa, Gabriella A.; Merkhofer, Richard M.; Kunzevitzky, Noelia J.; Goldberg, Jeffrey L.

    2016-01-01

    Purpose Human corneal endothelial cell (HCEC) density decreases with age, surgical complications, or disease, leading to vision impairment. Such endothelial dysfunction is an indication for corneal transplantation, although there is a worldwide shortage of transplant-grade tissue. To overcome the current poor donor availability, here we isolate, expand, and characterize HCECs in vitro as a step toward cell therapy. Methods Human corneal endothelial cells were isolated from cadaveric corneas and expanded in vitro. Cell identity was evaluated based on morphology and immunocytochemistry, and gene expression analysis and flow cytometry were used to identify novel HCEC-specific markers. The functional ability of HCEC to form barriers was assessed by transendothelial electrical resistance (TEER) assays. Results Cultured HCECs demonstrated canonical morphology for up to four passages and later underwent endothelial-to-mesenchymal transition (EnMT). Quality of donor tissue influenced cell measures in culture including proliferation rate. Cultured HCECs expressed identity markers, and microarray analysis revealed novel endothelial-specific markers that were validated by flow cytometry. Finally, canonical HCECs expressed higher levels of CD56, which correlated with higher TEER than fibroblastic HCECs. Conclusions In vitro expansion of HCECs from cadaveric donor corneas yields functional cells identifiable by morphology and a panel of novel markers. Markers described correlated with function in culture, suggesting a basis for cell therapy for corneal endothelial dysfunction. PMID:27196322

  16. Benzalkonium Chloride Suppresses Rabbit Corneal Endothelium Intercellular Gap Junction Communication

    PubMed Central

    Zhang, Zhenhao; Huang, Yue; Xie, Hui; Pan, Juxin; Liu, Fanfei; Li, Xuezhi; Chen, Wensheng; Hu, Jiaoyue; Liu, Zuguo

    2014-01-01

    Purpose Gap junction intercellular communication (GJIC) plays a critical role in the maintenance of corneal endothelium homeostasis. We determined if benzalkonium chloride (BAK) alters GJIC activity in the rabbit corneal endothelium since it is commonly used as a drug preservative in ocular eyedrop preparations even though it can have cytotoxic effects. Methods Thirty-six adult New Zealand albino rabbits were randomly divided into three groups. BAK at 0.01%, 0.05%, and 0.1% was applied twice daily to one eye of each of the rabbits in one of the three groups for seven days. The contralateral untreated eyes were used as controls. Corneal endothelial morphological features were observed by in vivo confocal microscopy (IVCM). Immunofluorescent staining resolved changes in gap junction integrity and localization. Western blot analysis and RT-PCR evaluated changes in levels of connexin43 (Cx43) and tight junction zonula occludens-1 (ZO-1) gene and protein expression, respectively. Cx43 and ZO-1 physical interaction was detected by immunoprecipitation (IP). Primary rabbit corneal endothelial cells were cultured in Dulbecco's Modified Eagle Medium (DMEM) containing BAK for 24 hours. The scrape-loading dye transfer technique (SLDT) was used to assess GJIC activity. Results Topical administration of BAK (0.05%, 0.1%) dose dependently disrupted corneal endothelial cell morphology, altered Cx43 and ZO-1 distribution and reduced Cx43 expression. BAK also markedly induced increases in Cx43 phosphorylation status concomitant with decreases in the Cx43-ZO-1 protein-protein interaction. These changes were associated with marked declines in GJIC activity. Conclusions The dose dependent declines in rabbit corneal endothelial GJIC activity induced by BAK are associated with less Cx43-ZO-1 interaction possibly arising from increases in Cx43 phosphorylation and declines in its protein expression. These novel changes provide additional evidence that BAK containing eyedrop preparations

  17. Lacosamide diminishes dryness-induced hyperexcitability of corneal cold sensitive nerve terminals.

    PubMed

    Kovács, Illés; Dienes, Lóránt; Perényi, Kristóf; Quirce, Susana; Luna, Carolina; Mizerska, Kamila; Acosta, M Carmen; Belmonte, Carlos; Gallar, Juana

    2016-09-15

    Lacosamide is an anti-epileptic drug that is also used for the treatment of painful diabetic neuropathy acting through voltage-gated sodium channels. The aim of this work was to evaluate the effects of acute application of lacosamide on the electrical activity of corneal cold nerve terminals in lacrimo-deficient guinea pigs. Four weeks after unilateral surgical removal of the main lachrimal gland in guinea pigs, corneas were excised and superfused in vitro at 34°C for extracellular electrophysiological recording of nerve terminal impulse activity of cold thermosensitive nerve terminals. The characteristics of the spontaneous and the stimulus-evoked (cooling ramps from 34°C to 15°C) activity before and in presence of lacosamide 100µM and lidocaine 100µM were compared. Cold nerve terminals (n=34) recorded from dry eye corneas showed significantly enhanced spontaneous activity (8.0±1.1 vs. 5.2±0.7imp/s; P<0.05) and cold response (21.2±1.7 vs. 16.8±1.3imp/s; P<0.05) as well as reduced cold threshold (1.5±0.1 vs. 2.8±0.2 Δ°C; P<0.05) to cooling ramps compared to terminals (n=58) from control animals. Both lacosamide and lidocaine decreased spontaneous activity and peak response to cooling ramps significantly (P<0.05). Temperature threshold was increased by the addition of lidocaine (P<0.05) but not lacosamide (P>0.05) to the irrigation fluid. In summary, the application of lacosamide results in a significant decrease of the augmented spontaneous activity and responsiveness to cold of corneal sensory nerves from tear-deficient animals. Based on these promising results we speculate that lacosamide might be used to reduce the hyperexcitability of corneal cold receptors caused by prolonged ocular surface dryness due to hyposecretory or evaporative dry eye disease.

  18. Corneal collagen crosslinking in keratoconus and other eye disease

    PubMed Central

    Alhayek, Adel; Lu, Pei-Rong

    2015-01-01

    Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen crosslinking (CXL) with riboflavin and Ultraviolet-A (UVA) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. Studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative spherical equivalent (SEQ) was reduced by an average of more than 1 D and refractive cylinder decreased by about 1 D. The major indication for the use of CXL is to inhibit the progression of corneal ecstasies, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photo ablation. This treatment has been used to treat infectious corneal ulcers with apparent favorable results. Most recent studies demonstrate the beneficial impact of CXL for iatrogenic ecstasies, pellucid marginal degeneration, infectious keratitis, bullous keratopathy and ulcerative keratitis. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subject to epithelial debridement and the application of a soft contact lens. Formation of temporary corneal haze, permanent scars, endothelial damage, treatment failure, sterile infiltrates, bullous keratopathy and herpes reactivation are the other reported complications of this procedure. PMID:25938065

  19. Corneal cross-linking in 9 horses with ulcerative keratitis

    PubMed Central

    2013-01-01

    Background Corneal ulcers are one of the most common eye problems in the horse and can cause varying degrees of visual impairment. Secondary infection and protease activity causing melting of the corneal stroma are always concerns in patients with corneal ulcers. Corneal collagen cross-linking (CXL), induced by illumination of the corneal stroma with ultraviolet light (UVA) after instillation of riboflavin (vitamin B2) eye drops, introduces crosslinks which stabilize melting corneas, and has been used to successfully treat infectious ulcerative keratitis in human patients. Therefore we decided to study if CXL can be performed in sedated, standing horses with ulcerative keratitis with or without stromal melting. Results Nine horses, aged 1 month to 16 years (median 5 years) were treated with a combination of CXL and medical therapy. Two horses were diagnosed with mycotic, 5 with bacterial and 2 with aseptic ulcerative keratitis. A modified Dresden-protocol for CXL could readily be performed in all 9 horses after sedation. Stromal melting, diagnosed in 4 horses, stopped within 24 h. Eight of nine eyes became fluorescein negative in 13.5 days (median time; range 4–26 days) days after CXL. One horse developed a bacterial conjunctivitis the day after CXL, which was successfully treated with topical antibiotics. One horse with fungal ulcerative keratitis and severe uveitis was enucleated 4 days after treatment due to panophthalmitis. Conclusions CXL can be performed in standing, sedated horses. We did not observe any deleterious effects attributed to riboflavin or UVA irradiation per se during the follow-up, neither in horses with infectious nor aseptic ulcerative keratitis. These data support that CXL can be performed in the standing horse, but further studies are required to compare CXL to conventional medical treatment in equine keratitis and to optimize the CXL protocol in this species. PMID:23803176

  20. Intrastromal Delivery of Bevacizumab Using Microneedles to Treat Corneal Neovascularization

    PubMed Central

    Kim, Yoo C.; Grossniklaus, Hans E.; Edelhauser, Henry F.; Prausnitz, Mark R.

    2014-01-01

    Purpose. This study tested the hypothesis that highly targeted intrastromal delivery of bevacizumab using coated microneedles allows dramatic dose sparing compared with subconjunctival and topical delivery for treatment of corneal neovascularization. Methods. Stainless steel microneedles 400 μm in length were coated with bevacizumab. A silk suture was placed in the cornea approximately 1 mm from the limbus to induce corneal neovascularization in the eyes of New Zealand white rabbits that were divided into different groups: untreated, microneedle delivery, topical eye drop, and subconjunctival injection of bevacizumab. All drug treatments were initiated 4 days after suture placement and area of neovascularization was measured daily by digital photography for 18 days. Results. Eyes treated once with 4.4 μg bevacizumab using microneedles reduced neovascularization compared with untreated eyes by 44% (day 18). Eyes treated once with 2500 μg bevacizumab using subconjunctival injection gave similar results to microneedle-treated eyes. Eyes treated once with 4.4 μg subconjunctival bevacizumab showed no significant effect compared with untreated eyes. Eyes treated with 52,500 μg bevacizumab by eye drops three times per day for 14 days reduced the neovascularization area compared with untreated eyes by 6% (day 18), which was significantly less effective than the single microneedle treatment. Visual exam and histological analysis showed no observable effect of microneedle treatment on corneal transparency or microanatomical structure. Conclusions. This study shows that microneedles can target drug delivery to corneal stroma in a minimally invasive way and demonstrates effective suppression of corneal neovascularization after suture-induced injury using a much lower dose compared with conventional methods. PMID:25212779

  1. Hyaluronate Acid-Dependent Protection and Enhanced Corneal Wound Healing against Oxidative Damage in Corneal Epithelial Cells

    PubMed Central

    Zhong, Jing; Deng, Yuqing; Tian, Bishan; Wang, Bowen; Sun, Yifang; Huang, Haixiang; Chen, Ling; Ling, Shiqi; Yuan, Jin

    2016-01-01

    Purpose. To evaluate the effects and mechanism of exogenous hyaluronate (HA) in promoting corneal wound healing. Methods. Human corneal epithelial cells (HCECs) were incubated with different concentrations of HA to evaluate their efficiency in promoting cell migration and their modulation of repair factors. After inducing hyperosmolar conditions, the cell morphologies, cell apoptosis, and expression levels of TNF-α and MMP-9 were detected to assess the protective role of HA. Corneal epithelium-injured rat models were established to test the therapeutic effects of 0.3% HA. Then, the wound healing rates, the RNA expression levels of inflammatory cytokines, and repair factors were examined. Results. HCECs in the 0.03% and 0.3% HA groups showed fewer morphological alterations and lower rates of cell apoptosis following preincubation with HA under hyperosmolar conditions, as well as the expression levels of MMP-9 and TNF-α. In the rat model, the areas of fluorescein staining in the corneas of 0.3% HA group were significantly smaller than the control group. The expression levels of IL-1β and MMP-9 were decreased, while CD44 and FN were increased in the 0.3% HA group. Conclusion. HA enhanced corneal epithelial cell wound healing by promoting cell migration, upregulating repair responses, and suppressing inflammatory responses. PMID:27190638

  2. Comparison of Goldmann applanation tonometry and Pascal dynamic contour tonometry in relation to central corneal thickness and corneal curvature

    PubMed Central

    Andreanos, Konstantinos; Koutsandrea, Chryssanthi; Papaconstantinou, Dimitris; Diagourtas, Andreas; Kotoulas, Andreas; Dimitrakas, Panagiotis; Moschos, Marilita M

    2016-01-01

    Purpose The aim of the study was to assess the influence of central corneal thickness (CCT) and corneal curvature in tonometry measurements taken by Goldmann applanation tonometry (GAT) and Pascal dynamic contour tonometry (DCT). Methods This was a prospective study of 185 eyes from 97 subjects, attending outpatient ophthalmology appointments, who underwent intraocular pressure measurements by GAT and Pascal DCT. CCT and corneal curvature were obtained using ultrasound pachymetry and Orbscan topography, respectively. All measurements were carried out among males and females during the period 2009–2012. Apart from the usual descriptive and exploratory data analysis, one-way analysis of variance and agreement analysis were performed, linear as well as intraclass correlation coefficients were estimated, and multiple scatter and Bland–Altman plots were produced. Results Mean IOP measurements obtained were 17.21±4.10 mmHg by DCT and 13.23±4.07 mmHg by GAT. Mean difference between the GAT and DCT measurements was 3.88±2.8 mmHg. Mean CCT and corneal curvature were 522.78±52 μm and 43.83±2.9823 D, respectively. Conclusion Intraocular pressure measured by GAT was consistently lower when compared with DCT, and this difference was greatest with thinner CCT. Flat corneas seem to influence GAT measurements compared to DCT. PMID:28003737

  3. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing

    PubMed Central

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C.; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  4. In vitro 3D corneal tissue model with epithelium, stroma, and innervation.

    PubMed

    Wang, Siran; Ghezzi, Chiara E; Gomes, Rachel; Pollard, Rachel E; Funderburgh, James L; Kaplan, David L

    2017-01-01

    The interactions between corneal nerve, epithelium, and stroma are essential for maintaining a healthy cornea. Thus, corneal tissue models that more fully mimic the anatomy, mechanical properties and cellular components of corneal tissue would provide useful systems to study cellular interactions, corneal diseases and provide options for improved drug screening. Here a corneal tissue model was constructed to include the stroma, epithelium, and innervation. Thin silk protein film stacks served as the scaffolding to support the corneal epithelial and stromal layers, while a surrounding silk porous sponge supported neuronal growth. The neurons innervated the stromal and epithelial layers and improved function and viability of the tissues. An air-liquid interface environment of the corneal tissue was also mimicked in vitro, resulting in a positive impact on epithelial maturity. The inclusion of three cell types in co-culture at an air-liquid interface provides an important advance for the field of in vitro corneal tissue engineering, to permit improvements in the study of innervation and corneal tissue development, corneal disease, and tissue responses to environmental factors.

  5. Corneal biomechanical data and biometric parameters measured with Scheimpflug-based devices on normal corneas

    PubMed Central

    Nemeth, Gabor; Szalai, Eszter; Hassan, Ziad; Lipecz, Agnes; Flasko, Zsuzsa; Modis, Laszlo

    2017-01-01

    AIM To analyze the correlations between ocular biomechanical and biometric data of the eye, measured by Scheimpflug-based devices on healthy subjects. METHODS Three consecutive measurements were carried out using the corneal visualization Scheimpflug technology (CorVis ST) device on healthy eyes and the 10 device-specific parameters were recorded. Pentacam HR-derived parameters (corneal curvature radii on the anterior and posterior surfaces; apical pachymetry; corneal volume; corneal aberration data; depth, volume and angle of the anterior chamber) and axial length (AL) from IOLMaster were correlated with the 10 specific CorVis ST parameters. RESULTS Measurements were conducted in 43 eyes of 43 volunteers (age 61.24±15.72y). The 10 specific CorVis ST data showed significant relationships with corneal curvature radii both on the anterior and posterior surface, pachymetric data, root mean square (RMS) data of lower-order aberrations, and posterior RMS of higher-order aberrations and spherical aberration of the posterior cornea. Anterior chamber depth showed a significant relationship, but there were no significant correlations between corneal volume, anterior chamber volume, mean chamber angle or AL and the 10 specific CorVis ST parameters. CONCLUSIONS CorVis ST-generated parameters are influenced by corneal curvature radii, some corneal RMS data, but corneal volume, anterior chamber volume, chamber angle and AL have no correlation with the biomechanical parameters. The parameters measured by CorVis ST seem to refer mostly to corneal properties of the eye. PMID:28251079

  6. Assessment of corneal properties based on statistical modeling of OCT speckle

    PubMed Central

    Jesus, Danilo A.; Iskander, D. Robert

    2016-01-01

    A new approach to assess the properties of the corneal micro-structure in vivo based on the statistical modeling of speckle obtained from Optical Coherence Tomography (OCT) is presented. A number of statistical models were proposed to fit the corneal speckle data obtained from OCT raw image. Short-term changes in corneal properties were studied by inducing corneal swelling whereas age-related changes were observed analyzing data of sixty-five subjects aged between twenty-four and seventy-three years. Generalized Gamma distribution has shown to be the best model, in terms of the Akaike’s Information Criterion, to fit the OCT corneal speckle. Its parameters have shown statistically significant differences (Kruskal-Wallis, p < 0.001) for short and age-related corneal changes. In addition, it was observed that age-related changes influence the corneal biomechanical behaviour when corneal swelling is induced. This study shows that Generalized Gamma distribution can be utilized to modeling corneal speckle in OCT in vivo providing complementary quantified information where micro-structure of corneal tissue is of essence. PMID:28101409

  7. Three-Dimensional Construction of a Rabbit Anterior Corneal Replacement for Lamellar Keratoplasty

    PubMed Central

    Pang, Kunpeng; Du, Liqun; Zhang, Kai; Dai, Chenyang; Ju, Chengqun; Zhu, Jing; Wu, Xinyi

    2016-01-01

    The aim of this study was to construct a rabbit anterior corneal replacement for transplantation using acellular porcine corneal matrix (APCM) and rabbit epithelial or stromal cells. APCM was prepared from fresh porcine cornea treated with 0.5% (wt./vol.) sodium dodecyl sulfate (SDS) solution. The expanded stromal cells were first injected into APCM parallel to its surface and were cultured in a shaking culture system for 7 days to obtain the stromal construct. Next, corneal epithelial cells were cultured on the stromal construct surface for another 7 days to obtain rabbit anterior corneal lamella. The construct had a phenotype similar to that of normal cornea, with high expression of cytokeratin 3 in the epithelial cell layer and vimentin in the stromal cells. More importantly, the construct integrated well with the implanted host corneal tissue, and the implant cornea maintained transparency in the 6-month follow-up, although there was a slight haze in the central corneal area. The endothelium in the surgery cornea had a similar cell density and mosaic pattern with normal cornea as shown by confocal laser corneal microscopy, and the regenerated corneal epithelial cells on the implant surface showed a similar morphology to that of natural epithelial cells. These results demonstrate that the constructed anterior corneal replacement exhibits an excellent biological property for lamellar keratoplasty and might be a possible alternative to human corneal tissue in the future. PMID:27930708

  8. Multipurpose Care Solution–Induced Corneal Surface Disruption and Pseudomonas aeruginosa Internalization in the Rabbit Corneal Epithelium

    PubMed Central

    Posch, Leila C.; Zhu, Meifang; Robertson, Danielle M.

    2014-01-01

    Purpose. To evaluate the effects of a chemically preserved multipurpose contact lens care solution (MPS) on the corneal epithelial surface and Pseudomonas aeruginosa (PA) internalization in the rabbit corneal epithelium. Methods. Rabbits were fit in one eye with a silicone hydrogel lens (balafilcon A) soaked overnight in a borate-buffered MPS (BioTrue). The contralateral eye was fit with a lens removed directly from the blister pack containing borate-buffered saline (control). Lenses were worn for 2 hours. Upon lens removal, corneas were challenged ex vivo with invasive PA strain 6487 and assessed for PA internalization. Ultrastructural changes were assessed using scanning electron (SEM) and transmission electron microscopy (TEM). Results. Scanning electron microscopy showed frank loss of surface epithelium in MPS-exposed eyes, while control eyes exhibited occasional loss of surface membranes but retention of intact junctional borders. Transmission electron microscopy data supported and extended SEM findings, demonstrating the presence of epithelial edema in MPS-treated eyes. There was a 12-fold increase in PA uptake into the corneal epithelium following wear of the MPS-treated lens compared to control (P = 0.008). Conclusions. These data demonstrate that corneal exposure to MPS during lens wear damages the surface epithelium and are consistent with our previous clinical data showing an increase in bacterial binding to exfoliated epithelial cells following MPS use with resultant increased risk for lens-mediated infection. These findings also demonstrate that the PA invasion assay may provide a highly sensitive quantitative metric for assessing the physiological impact of lens-solution biocompatibility on the corneal epithelium. PMID:24876286

  9. Modeling of Corneal and Retinal Pharmacokinetics after Periocular Drug Administration

    PubMed Central

    Amrite, Aniruddha C.; Edelhauser, Henry F.; Kompella, Uday B.

    2012-01-01

    Purpose To develop pharmacokinetics models to describe the disposition of small lipophilic molecules in the cornea and retina after periocular (subconjunctival or posterior subconjunctival) administration. Methods Compartmental pharmacokinetics analysis was performed on the corneal and retinal data obtained after periocular administration of 3 mg of celecoxib (a selective COX-2 inhibitor) to Brown Norway (BN) rats. Berkeley Madonna, a differential and difference equation–based modeling software, was used for the pharmacokinetics modeling. The data were fit to different compartment models with first-order input and disposition, and the best fit was selected on the basis of coefficient of regression and Akaike information criteria (AIC). The models were validated by using the celecoxib data from a prior study in Sprague-Dawley (SD) rats. The corneal model was also fit to the corneal data for prednisolone at a dose of 2.61 mg in albino rabbits, and the model was validated at two other doses of prednisolone (0.261 and 26.1 mg) in these rabbits. Model simulations were performed with the finalized model to understand the effect of formulation on corneal and retinal pharmacokinetics after periocular administration. Results Celecoxib kinetics in the BN rat cornea can be described by a two-compartment (periocular space and cornea, with a dissolution step for periocular formulation) model, with parallel elimination from the cornea and the periocular space. The inclusion of a distribution compartment or a dissolution step for celecoxib suspension did not lead to an overall improvement in the corneal data fit compared with the two-compartment model. The more important parameter for enhanced fit and explaining the apparent lack of an increase phase in the corneal levels is the inclusion of the initial leak-back of the dose from the periocular space into the precorneal area. The predicted celecoxib concentrations from this model also showed very good correlation (r = 0

  10. [The treatment of posner-schlossmann's syndrome. (acute glaucomatocyclitic crises) (author's transl)].

    PubMed

    Huismans, H

    1975-12-01

    In the surgery two patients with Posner-Schlossmann-Syndrome were observed for several months. The therapy of the acute attack secondary glaucoma was the combination of Diamox, Cortison - and Neosynephrine eye-drops. With Pilocarpine the I.O.P. lowering was insufficient. In one case corneal precipitates typical for Heterochromia complicata Fuchs were observed.

  11. Secondary acute anterior uveitis with hyphema in a purpose-bred kitten.

    PubMed

    Sorrell, Melanie S; Taylor, Karen H; Fish, Richard E

    2008-07-01

    The sudden onset of unilateral blepharospasm and hyphema, without evidence of corneal damage, initiated a thorough diagnostic work-up of an 11-wk-old purpose-bred intact male domestic shorthair kitten. Secondary acute anterior uveitis and hyphema were most likely due to trauma within the primary enclosure.

  12. Brittle Cornea Syndrome: Case Report with Novel Mutation in the PRDM5 Gene and Review of the Literature

    PubMed Central

    Avgitidou, Georgia; Siebelmann, Sebastian; Bachmann, Bjoern; Kohlhase, Juergen; Heindl, Ludwig M.; Cursiefen, Claus

    2015-01-01

    A 3-year-old boy presented with acute corneal hydrops on the left eye and spontaneous corneal rupture on the right eye. A diagnosis of brittle cornea syndrome was confirmed by molecular analysis. A novel mutation, the homozygous variant c.17T>G, p.V6G, was found in the gene for PR-domain-containing protein 5 (PRDM5) in exon 1. Brittle cornea syndrome is a rare connective tissue disease with typical ocular, auditory, musculoskeletal, and cutaneous disorders. Almost all patients suffer from declined vision due to corneal scarring, thinning, and rupture. The most common ophthalmologic findings include keratoconus, progressive central corneal thinning, high myopia, irregular astigmatism, retinal detachment, and high risk for spontaneous corneal or scleral rupture. In addition to describing the case with a novel mutation here we review the current literature on brittle cornea syndrome pathogenesis, clinical findings, and therapy. PMID:26221552

  13. Thermoelectrically controlled device for studies of temperature-induced corneal shrinkage

    NASA Astrophysics Data System (ADS)

    Borja, David; Manns, Fabrice; Fernandez, Viviana; Lamar, Peggy; Soederberg, Per G.; Parel, Jean-Marie A.

    2002-06-01

    The purpose of this study was to design and calibrate a device to measure the dynamics of thermal shrinkage in corneal and scleral strips. The apparatus consists of a thermoelectric cell controlled by a temperature controller designed to generate temperatures up to 90 degree(s)C in rectangular corneal strips; a copper cuvette filled with Dextran solution that holds the corneal strip and a displacement sensor that measures the change in length of the tissue during heat-induced shrinkage. The device was tested on corneal tissue from Florida Eye-Bank eyes that were cut into 2x4mm rectangular strips. Preliminary results indicate that our system can reproducibly create and accurately measure thermally induced corneal shrinkage. Shrinkage experiments will be used to optimize laser parameters for corneal shrinkage during laser thermokeratoplasty and laser scleral buckling.

  14. Assessing the phase retardation in corneal tissues using a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Calhoun, William; Weiblinger, Richard; Beylin, Alexander; Ilev, Ilko K.

    2013-08-01

    We developed and validated a versatile test method for precise quantification of phase retardation in corneal tissues using a femtosecond laser. It is based on an experimental system for direct measurement of corneal phase rotation due to corneal birefringence effects using a dual-polarizer, computer-controlled, femtosecond laser design. It also includes a comprehensive analytical model using Jones matrices. The test method presented is used for quantification of phase retardation in corneal tissues by employing the experimental data obtained from corneal phase rotation measurements and using analytical model assessments. The experimental and theoretical results obtained, and thus, the system's high accuracy and repeatability potential for assessing the corneal phase retardation are validated using control phase retardation evaluation.

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

    PubMed

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

    2015-10-01

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

  16. Early Intervention Stem Cell-Based Therapy (EISCBT) for Corneal Burns and Trauma

    DTIC Science & Technology

    2015-10-01

    lines. This initially involved obtaining appropriate permissions and establishing connections with surgeons in the area. Donated corneal tissue is...Stromal Stem Cells (CSSC) are obtained from biopsies of corneal tissue . The quality and potency of individual stem cell lines varies greatly from one...used for transplant and the remaining corneal rim serves as the source for stem cells. The tissue is de identified and permission was obtained by the

  17. Assessment of therapeutic options for reducing alkali burn-induced corneal neovascularization and inflammation.

    PubMed

    Bakunowicz-Łazarczyk, Alina; Urban, Beata

    2016-03-01

    This article aims to review and provide the current knowledge of the possibilities of topical treatment of corneal neovascularization due to alkali burns, evidenced by laboratory experiments, in vitro studies, and clinical trials published in the specialized literature. Authors present clinically relevant treatment of corneal neovascularization used in clinical practice, potential antiangiogenic topical therapeutics against corneal neovascularization, which are under investigation, and anti-angiogenic gene-therapy.

  18. Cyanoacrylate tissue adhesive for treatment of refractory corneal ulceration.

    PubMed

    Bromberg, Nancy M

    2002-03-01

    Isobutyl cyanoacrylate tissue adhesive (BCTA) was used in the treatment of refractory superficial corneal ulcers in 17 dogs, one cat, and one rabbit, present 2 weeks to 7 months (mean 6.8 weeks +/- 6.1) prior to referral. Little to no sedation was required in the majority of cases, with only topical anesthetic applied prior to debridement and BCTA application. The presence of the tissue adhesive caused mild discomfort for several days after application, as reported by the owners. The ulcers healed, and the tissue adhesive sloughed in approximately 3 weeks (+/- 1 week). Mild neovascularization of the cornea resolved with topical corticosteroids. The use of BCTA offers a simple, safe and noninvasive treatment for refractory corneal ulcers.

  19. Diabetes mellitus effect on rat corneal dielectric properties.

    PubMed

    Olszewski, J; Marzec, E; Florek, E; Kulza, M

    2012-03-01

    In the course of the study, we carried out a dielectric examination to determine the effect of diabetes mellitus on the rat corneal function. Measurements were performed over the frequency range of 500 Hz-100 kHz in air and at the temperatures from 25 to 150°C. The frequency dependencies of the loss tangent for the healthy and the diabetic cornea exhibit two peaks at 2 kHz and 16 kHz in the α-dispersion region. The amplitude of these both peaks is smaller for the diabetic cornea than that for the healthy one. The temperature dependencies of the loss tangent for the healthy and the diabetic cornea reveal β-relaxation in the range of 30-70°C and 50-90°C, respectively. The present study exhibits that the dielectric spectroscopy is useful in detection of the effect of diabetes mellitus on the corneal molecular behavior.

  20. Keratometry and corneal topography using multiple delay element OCT

    NASA Astrophysics Data System (ADS)

    Plesea, Lucian; Podoleanu, Adrian G.

    2008-02-01

    We have presented previously a novel method for the evaluation of the surface shape of an object, with immediate application to measurement of cornea shape. This method uses single shot C-scans obtained by using a multiple delay element (MDE) in the reference path of an OCT system. A calibrated MDE-OCT system can be used to measure the elevation of points on the cornea, in contrast to existing methods which are based on measurement of the cornea slope. The associated algorithm for extracting corneal topography data points from the MDE-OCT C-Scan image will be presented, data points which can then be used to calculate the Zernike coefficients for the cornea shape. The differences between the existing systems and the MDE-OCT method for keratometry and corneal topography are discussed.

  1. Jaw, blink and corneal reflex latencies in multiple sclerosis.

    PubMed Central

    Sanders, E A; Ongerboer de Visser, B W; Barendswaard, E C; Arts, R J

    1985-01-01

    Jaw, blink and corneal reflexes, which all involve the trigeminal system, were recorded in 54 patients with multiple sclerosis; thirty-seven of these patients were classified as having definite multiple sclerosis and 17 as indefinite multiple sclerosis, according to Schumacher's criteria. The jaw reflex was abnormal less frequently than either of the other two reflexes, but in four cases it was the only abnormal reflex found. Testing a combination of two or three trigeminal reflexes did not yield a higher incidence of abnormalities than testing the blink or corneal reflex alone. Nine patients showed abnormal reflexes which were unexpected on the basis of clinical symptoms. The combined recordings demonstrate at least one abnormal reflex in 74% of the patients. The various types of reflex abnormalities reflect major damage to different parts of the trigeminal system and may therefore make an important contribution to the diagnosis of multiple sclerosis. PMID:4087004

  2. Light scattering from human corneal grafts: Bulk and surface contribution

    NASA Astrophysics Data System (ADS)

    Latour, Gaël; Georges, Gaëlle; Lamoine, Laure Siozade; Deumié, Carole; Conrath, John; Hoffart, Louis

    2010-09-01

    The cornea is the only transparent tissue in the body. The transparency is the main characteristic of the corneal tissue, and depends not only on the transmission coefficient but also on the losses by scattering and absorption. The scattering properties of the cornea tissues become one of the most important parameters in the case of the corneal graft. These scattering properties are studied in this paper in the reflected half area, similar to the diagnosis configuration. We quantify the influence of the cornea thickness and of the epithelial layer on scattering level. The technique of ellipsometry on scattered field is also used to analyze the polarization properties in order to determine the origin of scattering (surface and/or bulk).

  3. [Gonococcal conjunctivitis complicated by perforating corneal abscess in an adult].

    PubMed

    Gambrelle, J; Ponceau, B; Duquesne, N; Crepet, H; Fleury, J; Burillon, C; Grange, J D; Kodjikian, L

    2007-09-01

    We present a case of bilateral purulent conjunctivitis complicated by ocular perforation of the right eye secondary to fulminant corneal melt in a 29-year-old man. He developed urethritis after a sexual contact with a prostitute 3 weeks previously. Microbiological analyses of conjunctival and urinary cultures were positive for Neisseria gonorrhoeae resistant to penicillins, tetracyclines, and fluoroquinolones. Progression was favorable with a 15-day course of high doses of parenterally administered antibiotics associating imipenem and fosfomycin. Keratoplasty was done after 3 months. This observation is a good example of the problems raised by gonococcal conjunctivitis in adults. Extremely rare in developed countries, it remains widely unrecognized by ophthalmologists. It is a sexually transmitted disease usually resulting from autoinoculation from an infected genital site. The risk of marginal purulent corneal melt, which can lead to fulminant perforation, warrants prompt microbiological analysis and early parenteral antibiotic treatment.

  4. Anterior segment surgery early after corneal wound repair.

    PubMed Central

    Maul, E; Muga, R

    1977-01-01

    Penetrating wounds of the cornea require immediate repair, generally within 24 hours. Tight closure of the wound and a reformed anterior chamber are the primary goals of surgery. However, there is no guarantee that further surgery will not be required for maintaining the healthy function of the anterior segment. At the second operation the effect of the procedure on the previously repaired wound is of prime importance, since in many cases the operation needs to be done before corneal healing is completed. In our series the lens, which was either partially or completely cataractous at the initial operation, became intumescent at different times afterwards, and an immediate removal was necessary. No change in the preoperative wound sealing or transparency of the cornea could be detected after lens surgery performed between 24 hours and 21 days from the initial corneal repair. PMID:603786

  5. Self inflicted corneal abrasions due to delusional parasitosis

    PubMed Central

    Meraj, Adeel; Din, Amad U; Larsen, Lynn; Liskow, Barry I

    2011-01-01

    The authors report a case of self inflicted bilateral corneal abrasions and skin damage due to ophthalmic and cutaneous delusional parasitosis. A male in his 50s presented with a 10 year history of believing that parasites were colonizing his skin and biting into his skin and eyes. The patient had received extensive medical evaluations that found no evidence that symptoms were due to a medical cause. He was persistent in his belief and had induced bilateral corneal abrasions and skin damage by using heat lamps and hair dryers in an attempt to disinfect his body. The patient was treated with olanzapine along with treatment for his skin and eyes. His delusional belief system persisted but no further damage to his eyes and skin was noted on initial follow-up. PMID:22689836

  6. Molecular underpinnings of corneal angiogenesis: advances over the past decade

    PubMed Central

    Abdelfattah, Nizar Saleh; Amgad, Mohamed; Zayed, Amira A.; Hussein, Heba; Abd El-Baky, Nawal

    2016-01-01

    The cornea is maintained in an avascular state by maintaining an environment whereby anti-angiogenic factors take the upper hand over factors promoting angiogenesis. Many of the common pathologies affecting the cornea involve the disruption of such equilibrium and the shift towards new vessel formation, leading to corneal opacity and eventually-vision loss. Therefore it is of paramount importance that the molecular underpinnings of corneal neovascularization (CNV) be clearly understood, in order to develop better targeted treatments. This article is a review of the literature on the recent discoveries regarding pro-angiogenic factors of the cornea (such as vascular endothelial growth factors, fibroblast growth factor and matrix metalloproteinases) and anti-angiogenic factors of the cornea (such as endostatins and neostatins). Further, we review the molecular underpinnings of lymphangiogenesis, a process now known to be almost separate from (yet related to) hemangiogenesis. PMID:27275438

  7. High-risk corneal allografts: A therapeutic challenge

    PubMed Central

    Yu, Tian; Rajendran, Vijayalakshmi; Griffith, May; Forrester, John V; Kuffová, Lucia

    2016-01-01

    Corneal transplantation is the most common surgical procedure amongst solid organ transplants with a high survival rate of 86% at 1-year post-grafting. This high success rate has been attributed to the immune privilege of the eye. However, mechanisms originally thought to promote immune privilege, such as the lack of antigen presenting cells and vessels in the cornea, are challenged by recent studies. Nevertheless, the immunological and physiological features of the cornea promoting a relatively weak alloimmune response is likely responsible for the high survival rate in “low-risk” settings. Furthermore, although corneal graft survival in “low-risk” recipients is favourable, the prognosis in “high-risk” recipients for corneal graft is poor. In “high-risk” grafts, the process of indirect allorecognition is accelerated by the enhanced innate and adaptive immune responses due to pre-existing inflammation and neovascularization of the host bed. This leads to the irreversible rejection of the allograft and ultimately graft failure. Many therapeutic measures are being tested in pre-clinical and clinical studies to counter the immunological challenge of “high-risk” recipients. Despite the prevailing dogma, recent data suggest that tissue matching together with use of systemic immunosuppression may increase the likelihood of graft acceptance in “high-risk” recipients. However, immunosuppressive drugs are accompanied with intolerance/side effects and toxicity, and therefore, novel cell-based therapies are in development which target host immune cells and restore immune homeostasis without significant side effect of treatment. In addition, developments in regenerative medicine may be able to solve both important short comings of allotransplantation: (1) graft rejection and ultimate graft failure; and (2) the lack of suitable donor corneas. The advances in technology and research indicate that wider therapeutic choices for patients may be available to

  8. Conjunctival and corneal sensitivity in patients under topical antiglaucoma treatment.

    PubMed

    Romero-Díaz de León, Lorena; Morales-León, Jorge-Emmanuel; Ledesma-Gil, Jasbeth; Navas, Alejandro

    2016-06-01

    The purpose of the study is to measure corneal and conjunctival sensitivity in patients under glaucoma topical treatment as compared to a control group. It is a case-control study. Corneal and conjunctival esthesiometry were carried out through a Cochet-Bonnet esthesiometer. We took healthy individuals as controls, who did not use any type of ophthalmic topical medications and without history of ocular surface pathology or irritation. The study group was subdivided per number of applications (1, 2, and 3 or more applications). From a total 182 eyes from 91 patients, of which 26 (28.57 %) were controls and 65 (71.43 %) were in the study group, a mean corneal sensitivity of 58.98 ± 2.25 mm was found in the control group and 52.97 ± 6.41 mm in patients using topical medication. Mean conjunctival sensitivity was 18.80 ± 5.40 mm in the control group and 11.76 ± 5.45 mm in the study group. There was no statistically significant difference among groups when separated by 1, 2, and 3 or more applications. Eyes under use of timolol-containing medications showed lower sensitivity values as compared to other topical antiglaucoma medications. Corneal and conjunctival sensitivities are diminished in patients with chronic use of topical hypotensive medications and these results can explain the lack of correlation between signs and symptoms that is typically found in patients treated for glaucoma or ocular hypertension.

  9. [Prognostic category of corneal transplantation in a referal center].

    PubMed

    Verdiguel-Sotelo, Karla; Carrasco-Quiroz, Arturo; Rangel-Servín, Josué

    2016-01-01

    Introducción: la queratoplastía penetrante (QP) es considerada como el trasplante orgánico más frecuentemente realizado y con mayor éxito. Las indicaciones de trasplante de córnea han cambiado con el tiempo y varían en función del país. Se han identificado factores de riesgo de rechazo corneal, como edad, vascularización corneal, cirugías oculares, etcétera. El objetivo fue identificar la categoría pronóstica, el grupo de riesgo y los factores asociados de pacientes con trasplante de córnea del Centro Médico Nacional La Raza. Métodos: se hizo un estudio transversal, analítico, observacional y ambispectivo, con fines ópticos y terapéuticos, de pacientes de la base de datos de trasplante corneal registrados entre 2011 y 2013 en el centro médico mencionado. Resultados: se obtuvieron 539 registros. El diagnóstico más frecuente fue el queratocono (29.1 %), en segundo lugar el leucoma (27.8 %) y la queratopatía bulosa pseudofáquica (25.6 %) en tercero. El 57.5 % de los pacientes correspondieron a la categoría pronóstica 2, con pronóstico de transparencia corneal muy bueno. Conclusiones: el diagnóstico más frecuente en la base de datos de trasplante de córnea fue el queratocono. Es necesaria una actualización de la clasificación pronóstica con base en todos los factores asociados conocidos, a fin de ser más acertados en el pronóstico del TC.

  10. Corneal contact times of ophthalmic vehicles. Evaluation by microscintigraphy.

    PubMed

    Trueblood, J H; Rossomondo, R M; Wilson, L A; Carlton, W H

    1975-02-01

    Lacrimal microscintigraphy, in conjunction with a recently developed computer system, was used to evaluate the corneal contact time of three ophthalmic vehicles in 18 humans. The percentage of a radioactively labeled vehicle remaining over the cornea after 90 seconds was 2.9% plus and minus 2.2% for saline, 4.3% plus and minus 2.4% for polyvinyl alcohol, and 8.8% plus and minus 4.1% for hydroxypropyl methylcellulose.

  11. Efficacy of pig-to-rhesus lamellar corneal xenotransplantation.

    PubMed

    Choi, Hyuk Jin; Kim, Mee Kum; Lee, Hyun Ju; Ko, Jung Hwa; Jeong, So Hee; Lee, Jae-Il; Oh, Byoung-Chol; Kang, Hee Jung; Wee, Won Ryang

    2011-08-22

    PURPOSE. To solve the shortage of donor corneas, a decellularizing method based on hypertonic saline treatment was introduced, and a favorable outcome was observed in pig-to-rabbit lamellar corneal transplantation. This study was an investigation of the efficacy of pig-to-nonhuman primate lamellar corneal transplantation, using both decellularized and fresh porcine corneas to assess feasibility as a substitute for human corneas. METHODS. Nine Chinese rhesus macaques underwent lamellar corneal transplantation using both decellularized (n = 5) and fresh (n = 4) porcine corneas. Clinically acceptable graft size (7.5 mm in diameter) and minimal immunosuppression based on topical and systemic corticosteroids were applied. Rejection signs, histology of porcine grafts, and serial changes in recipients' blood profile, including memory T-cell subset, anti-α-Gal and donor pig-specific antibodies, and complement were evaluated. Changes in aqueous complement concentration were also assessed at 4 weeks after transplantation. RESULTS. Of the decellularized porcine lamellar grafts, 80% remained transparent for more than 6 months, whereas half of the fresh porcine lamellar grafts developed chronic rejection. Rejected grafts showed extensive cellular infiltration, predominantly CD8(+) T lymphocytes and macrophages. Immunologic profiles of the recipients with rejected grafts showed a significant increase in the concentration of aqueous complement, an enhancement of memory T cells, and an abrupt increase in donor pig-specific antibodies. CONCLUSIONS. The findings suggested that decellularized porcine cornea could be a promising substitute for human corneal allograft. Fresh porcine cornea may be a feasible option for a substitute if combined with more potent immunosuppression or if obtained from transgenic pigs with complement-regulatory proteins.

  12. Corneal squamous cell carcinoma in a Border Collie.

    PubMed

    Busse, Claudia; Sansom, Jane; Dubielzig, R R; Hayes, Alison

    2008-01-01

    A 6-year-old, female, spayed Border Collie was presented to the Unit of Comparative Ophthalmology at the Animal Health Trust with a 6-month history of a progressive nonpainful opacity of the left cornea. A keratectomy was performed and the tissue submitted for histopathology. The diagnosis was squamous cell carcinoma. There has been no recurrence of the neoplasm to date (5 months). Canine corneal squamous cell carcinoma (SCC) has not been reported previously in the UK.

  13. Perforating corneal injury in rat and pentadecapeptide BPC 157.

    PubMed

    Masnec, Sanja; Kokot, Antonio; Zlatar, Mirna; Kalauz, Miro; Kunjko, Kristian; Radic, Bozo; Klicek, Robert; Drmic, Domagoj; Lazic, Ratimir; Brcic, Luka; Radic, Radivoje; Ivekovic, Renata; Seiwerth, Sven; Sikiric, Predrag

    2015-07-01

    Based on its healing effects in various tissues, we hypothesized that the stable gastric pentadecapeptide BPC 157 heals corneal ulcerations in rats and effects corneal transparency. We made a penetrant linear 2-mm incision in the paralimbal region of the left cornea at the 5 o'clock position with a 20-gauge MVR incision knife at 45° under an operating microscope. Medication was BPC 157 (2 pg/mL, 2 ng/mL, and 2 μg/mL distilled water, two eye drops/left rat eye) immediately after injury induction and then every 8 h up to 120 h; controls received an equal volume of distilled water. In contrast to the poor healing response in controls, BPC 157 significantly accelerated the healing process in 2 μg and 2 ng BPC 157-treated eyes, starting 24 h after the injury, and the fluorescein and Seidel tests became negative. The epithelial defects were completely healed at 72 h (2 μg BPC 157-treated group) and at 96 h (2 ng BPC 157-treated group) after injury. Aqueous cells were absent at 96 h and 120 h after injury in the 2 μg and 2 ng BPC 157-treated groups, respectively. In conclusion, BPC 157 effects the rapid regaining of corneal transparency. Whereas controls developed new vessels that grew from the limbus to the penetrated area, BPC 157-treated rats generally had no new vessels, and those that did form in the limbus did not make contact with the penetrated area. Thus, BPC 157 eye drops successfully close perforating corneal incisions in rats.

  14. Dynamic Regulation of Barrier Integrity of the Corneal Endothelium

    PubMed Central

    Srinivas, Sangly P.

    2010-01-01

    The corneal endothelium maintains stromal deturgescence, which is a prerequisite for corneal transparency. The principal challenge to stromal deturgescence is the swelling pressure associated with the hydrophilic glycosaminoglycans in the stroma. This negative pressure induces fluid leak into the stroma from the anterior chamber, but the rate of leak is restrained by the tight junctions (TJs) of the endothelium. This role of the endothelium represents its barrier function. In healthy cornea, the fluid leak is counterbalanced by an active fluid pump mechanism associated with the endothelium itself. Although this Pump-Leak hypothesis was postulated several decades ago, the mechanisms underlying regulation of the balance between the pump and leak functions remain largely unknown. In the last couple of decades, the ion transport systems that support the fluid pump activity have been discovered. In contrast, despite significant evidence for corneal edema secondary to endothelial barrier dysfunction, the molecular aspects underlying its regulation are relatively unknown. Recent findings in our laboratory, however, indicate that barrier integrity (i.e., structural and functional integrity of the TJs) of the endothelium is sensitive to remodeling of its peri-junctional actomyosin ring (PAMR), which is located at the apical junctional complex. This review provides a focused perspective on dynamic regulation of the barrier integrity of endothelium vis-à-vis plasticity of the PAMR and its association with cell signaling downstream of small GTPases of the Rho family. Based on findings to date, it appears that development of specific pharmacological strategies to treat corneal edema in response to inflammatory stress would be possible in the near future. PMID:20142793

  15. Ultraviolet Irradiation-Induced Volume Alteration of Corneal Epithelial Cells

    PubMed Central

    Wang, Ling; Lu, Luo

    2016-01-01

    Purpose The purpose of the study is to understand how extracellular stresses, such as ultraviolet (UV) irradiation, affect corneal epithelial cells. Cell volume changes, damage to corneal epithelial integrity, and cellular responses were assessed after exposure to UVC stresses. Methods Primary human and rabbit corneal epithelial cells were exposed to UVC light in culture conditions. Ultraviolet C irradiation–induced changes in cell size and volume were measured by real-time microscopy and self-quenching of the fluorescent dye calcein, respectively. The effects of UVC irradiation on Src and focal adhesion kinase (FAK) phosphorylation and FAK-dependent integrin signaling were detected by ELISA, immunoblotting, and immunostaining. Results Ultraviolet C irradiation induced both size and volume shifts in human and rabbit corneal epithelial cells. Ultraviolet C irradiation-induced decrease of cell volume elicited activation of Src and FAK, characterized by increased phosphorylations of SrcY416, FAKY397, and FAKY925. In addition, immunostaining studies showed UVC irradiation–induced increases in phosphorylation of FAK and formation of integrin β5 clustering. Application of Kv channel blockers, including 4-aminopyridine (4-AP), α-DTX, and depressing substance-1 (BDS-1), effectively suppressed UVC irradiation–induced cell volume changes, and subsequently inhibited UVC irradiation–induced phosphorylation of Src/FAK, and formation of integrin β5 clustering, suggesting UVC irradiation–induced volume changes and Src/FAK activation. Hyperosmotic pressure–induced volume decreases were measured in comparison with effects of UVC irradiation on volume and Src/FAK activation. However, Kv channel blocker, 4-AP, had no effect on hyperosmotic pressure–induced responses. Conclusions The present study demonstrates that UVC irradiation–induced decreases in cell volume lead to Src/FAK activation due to a rapid loss of K ions through membrane Kv channels. PMID:27978555

  16. Role of Thrombospondin-1 in Repair of Penetrating Corneal Wounds

    PubMed Central

    Blanco-Mezquita, José Tomás; Hutcheon, Audrey E. K.; Zieske, James D.

    2013-01-01

    Purpose. Thrombospondin-1 (THBS1) has been suggested as a corneal wound-healing modulator. Therefore, we compromised the integrity of the cornea to elucidate the role of THBS1. Methods. Full-thickness penetrating corneal incisions (1.5 mm) were created in wild type (WT, 129S2/SvPas) and THBS1-deficient mice (Thbs1−/−, 129S2/SvPas-Thbs1tm1Hyn/Thbs1tm1Hyn), and allowed to heal up to 1 month, while being monitored by slit-lamp and intravital corneal examinations. Corneas also were examined by transmission electron microscopy and indirect immunofluorescence. To determine how THBS1 was involved in the healing process, we examined THBS1 and α-smooth muscle actin (SMA), a marker of myofibroblasts and myoepithelial cells. Results. In WT mice by 1 month, corneas appeared transparent with a thin scar, and endothelium and Descemet's membrane (DM) were restored. In contrast, Thbs1−/− corneas exhibited chronic edema and persistent opacity after wounding. The DM and endothelium were not restored, and wound contraction was impaired. The THBS1 was localized in epithelial cells at early stages of the healing process, and in the stroma and endothelial cells during later stages. The SMA-positive epithelial cells and myofibroblasts were observed within the healing area at day 4, peaked at day 14, and disappeared at day 30. The SMA-positive cells were reduced greatly in Thbs1−/− mice. Conclusions. In the current study, we demonstrated that corneal restoration is strikingly compromised by a penetrating incision in Thbs1−/− mice. The wound results in persistent edema and wound gaping. This appears to be the result of the lack of endothelial migration and DM restoration. In addition, myofibroblast formation is compromised, resulting in the lack of wound contraction. PMID:23963165

  17. Derivation of Corneal Keratocyte-Like Cells from Human Induced Pluripotent Stem Cells

    PubMed Central

    Naylor, Richard W.; McGhee, Charles N. J.; Cowan, Chad A.; Davidson, Alan J.; Holm, Teresa M.; Sherwin, Trevor

    2016-01-01

    Corneal diseases such as keratoconus represent a relatively common disorder in the human population. However, treatment is restricted to corneal transplantation, which only occurs in the most advanced cases. Cell based therapies may offer an alternative approach given that the eye is amenable to such treatments and corneal diseases like keratoconus have been associated specifically with the death of corneal keratocytes. The ability to generate corneal keratocytes in vitro may enable a cell-based therapy to treat patients with keratoconus. Human induced pluripotent stem cells (hiPSCs) offer an abundant supply of cells from which any cell in the body can be derived. In the present study, hiPSCs were successfully differentiated into neural crest cells (NCCs), the embryonic precursor to keratocytes, and then cultured on cadaveric corneal tissue to promote keratocyte differentiation. The hiPSC-derived NCCs were found to migrate into the corneal stroma where they acquired a keratocyte-like morphology and an expression profile similar to corneal keratocytes in vivo. These results indicate that hiPSCs can be used to generate corneal keratocytes in vitro and lay the foundation for using these cells in cornea cell-based therapies. PMID:27792791

  18. Molecular mechanism of the inhibition effect of Lipoxin A4 on corneal dissolving pathology process

    PubMed Central

    Zhou, Hong-Yan; Hao, Ji-Long; Bi, Miao-Miao; Wang, Shuang; Zhang, Hong; Zhang, Wen-Song

    2013-01-01

    AIM Excessive dissolve of corneal tissue induced by MMPs which were activated by cytokins and chemokines will lead to corneal ulcer. The molecular mechanism of Lipoxin A4 (LXA4) on corneal collagen degradation in three dimensions was investigated. METHODS Rabbit corneal fibroblasts were harvested and suspended in serum-free MEM. Type I collagen, DMEM, collagen reconstitution buffer and corneal fibroblast suspension were mixed on ice. The resultant mixture solidified in an incubator, after which test reagents and plasminogen was overlaid and the cultures were returned to the incubator. The supernatants from collagen gel incubations were collected and the amount of hydroxyproline in the hydrolysate was measured. Immunoblot analysis of MMP-1, -3 and TMMP-1,-2 was performed. MMP-2,-9 was detected by the method of Gelatin zymography. Cytotoxicity assay was measured. RESULTS LXA4 inhibited corneal collagen degradation in a dose and time manner. LXA4 inhibited the IL-1β induced increases in the pro-MMP-1, -2, -3, -9 and active MMP-1, -2, -3, -9 in a concentration dependent manner. LXA4 could also inhibit the IL-1β induced increases in TIMP-1, -2. CONCLUSION As a potent anti-inflammation reagent, LXA4 can inhibit corneal collagen degradation induced by IL-1β in corneal fibroblasts thus inhibiting corneal dissolving pathology process. PMID:23550231

  19. Robust automatic segmentation of corneal layer boundaries in SDOCT images using graph theory and dynamic programming.

    PubMed

    Larocca, Francesco; Chiu, Stephanie J; McNabb, Ryan P; Kuo, Anthony N; Izatt, Joseph A; Farsiu, Sina

    2011-06-01

    Segmentation of anatomical structures in corneal images is crucial for the diagnosis and study of anterior segment diseases. However, manual segmentation is a time-consuming and subjective process. This paper presents an automatic approach for segmenting corneal layer boundaries in Spectral Domain Optical Coherence Tomography images using graph theory and dynamic programming. Our approach is robust to the low-SNR and different artifact types that can appear in clinical corneal images. We show that our method segments three corneal layer boundaries in normal adult eyes more accurately compared to an expert grader than a second grader-even in the presence of significant imaging outliers.

  20. Effects of Positive Acceleration on Corneal Stability in Photorefractive Keratectomy (PRK) Subjects

    DTIC Science & Technology

    2005-06-01

    Corneal Topography …………………..………………………………... 17 Visual Acuity…………………………………………………………..... 18 Discussion...Change As A Function of +Gz………………………. 15 Figure 12: Autokeratometry Changes As A Function Of +Gz……………………. 16 Figure 13: Corneal Topography ...both eyes within 10 minutes. Corneal topography data was collected using the EyeSys Vista™ HANDHELD CORNEAL TOPOGRAPHER (HCT) (Figure 8

  1. Autophagy and Macropinocytosis: Keeping an Eye on the Corneal/Limbal Epithelia

    PubMed Central

    Peng, Han; Park, Jong Kook; Lavker, Robert M.

    2017-01-01

    Autophagy and macropinocytosis are processes that are vital for cellular homeostasis, and help cells respond to stress and take up large amounts of material, respectively. The limbal and corneal epithelia have the machinery necessary to carry out both processes; however, autophagy and macropinocytosis are relatively understudied in these two epithelia. In this Perspectives, we describe the basic principles behind macropinocytosis and autophagy, discuss how these two processes are regulated in the limbal and corneal epithelia, consider how these two processes impact on the physiology of limbal and corneal epithelia, and elaborate on areas of future research in autophagy and macropinocytosis as related to the limbal/corneal epithelia. PMID:28118670

  2. Evaluation of Corneal Deformation Analyzed with Scheimpflug Based Device in Healthy Eyes and Diseased Ones

    PubMed Central

    Lanza, Michele; Cennamo, Michela; Iaccarino, Stefania; Irregolare, Carlo; Bifani, Mario; Gironi Carnevale, Ugo Antonello

    2014-01-01

    This study was designed to evaluate the correlation between corneal biomechanical and morphological data in healthy eyes, eyes that underwent myopic photorefractive keratectomy (PRK), keratoconus affected eyes, and keratoconus affected eyes that underwent corneal collagen crosslinking (CCC). Complete clinical eye examination of all eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany) and biomechanical (Corvis ST, Oculus, Wetzlar, Germany) evaluation. Differences among Corvis ST (CST) parameters in the different groups have been performed. Linear regression between central corneal thickness (CCT), intraocular pressure (IOP), and anterior corneal curvature measured with Sim'K (KM), versus corneal deformation parameters measured with Corvis ST in the different groups, has been run using SPSS software version 18.0. We evaluated 64 healthy eyes of 64 patients with a mean refractive error of −0.65 ± 1.68 D (measured as spherical equivalent), 17 eyes of 17 patients that underwent myopic PRK for a mean refractive defect of −4.91 ± 2.05 D (measured as spherical equivalent), 16 eyes of 16 patients affected by keratconus (stage 2-3 of Amsler Classification), and 13 eyes of 13 patients affected by keratoconus that underwent CCC. Our data suggest that corneal curvature would have a greater influence on corneal deformation than CCT; in fact KM values are more strongly associated with more CST parameters both about corneal change in shape and both about the corneal ability to come back at original shape. PMID:25054144

  3. Location of penetration and metabolic barriers to levobunolol in the corneal epithelium of the pigmented rabbit.

    PubMed

    Ashton, P; Wang, W; Lee, V H

    1991-11-01

    The objective of this study was to determine which of the five or six corneal epithelial layers was rate-limiting in the corneal penetration and metabolism of levobunolol in the pigmented rabbit. Corneal penetration and metabolism were evaluated using the isolated cornea in the modified Ussing chamber. Levobunolol and its metabolite, dihydrolevobunolol, were assayed by reversed phase high-performance liquid chromatography using spectrophotometric detection. EDTA (0.1 and 0.5%) and benzalkonium chloride (0.005-0.05%) were used to disrupt the integrity of the corneal epithelial layers. EDTA, which loosened the tight junctions between the superficial corneal epithelial cells, reduced both the transcorneal flux and metabolism of levobunolol. In contrast, benzalkonium chloride, which disrupted the integrity of the outermost corneal epithelial layers, enhanced the transcorneal levobunolol flux while reducing its extent of metabolism. The extent of enhancement in transcorneal flux afforded by 0.025% benzalkonium chloride was comparable to that seen in the deepithelized cornea. Within 5 min of contact by the corneal epithelium with this preservative, the ratio of dihydrolevobunolol concentration on the endothelial to the epithelial side was reduced by two-thirds. Although direct confirmation is required, the above findings are consistent with the hypothesis that the rate-limiting layer to corneal penetration of levobunolol resides in the outermost two to three layers of the corneal epithelium, whereas the metabolic barrier resides in deeper lying regions.

  4. Numerical model of optical coherence tomographic vibrography imaging to estimate corneal biomechanical properties

    PubMed Central

    Kling, Sabine; Akca, Imran B.; Chang, Ernest W.; Scarcelli, Giuliano; Bekesi, Nandor; Yun, Seok-Hyun; Marcos, Susana

    2014-01-01

    Most techniques measuring corneal biomechanics in vivo are biased by side factors. We demonstrate the ability of optical coherence tomographic (OCT) vibrography to determine corneal material parameters, while reducing current prevalent restrictions of other techniques (such as intraocular pressure (IOP) and thickness dependency). Modal analysis was performed in a finite-element (FE) model to study the oscillation response in isolated thin corneal flaps/eye globes and to analyse the dependency of the frequency response function on: corneal elasticity, viscoelasticity, geometry (thickness and curvature), IOP and density. The model was verified experimentally in flaps from three bovine corneas and in two enucleated porcine eyes using sound excitation (100–110 dB) together with a phase-sensitive OCT to measure the frequency response function (range 50–510 Hz). Simulations showed that corneal vibration in flaps is sensitive to both, geometrical and biomechanical parameters, whereas in whole globes it is primarily sensitive to corneal biomechanical parameters only. Calculations based on the natural frequency shift revealed that flaps of the posterior cornea were 0.8 times less stiff than flaps from the anterior cornea and cross-linked corneas were 1.6 times stiffer than virgin corneas. Sensitivity analysis showed that natural vibration frequencies of whole globes were nearly independent from corneal thickness and IOP within the physiological range. OCT vibrography is a promising non-invasive technique to measure corneal elasticity without biases from corneal thickness and IOP. PMID:25320067

  5. [Corneal metabolism with contact lenses in competitive sports].

    PubMed

    Schnell, D; Khaireddin, R

    2013-06-01

    The corneal metabolism during the use of contact lenses plays an important role for permanent corneal health, especially in competitive sports. Thus, it is important to understand the steps of corneal metabolism in general and during highly competitive sports activity in particular. The aim of this review is to summarize the current knowledge on physiological and biochemical effects of contact lens wear. Of the energy requirements of the cornea 75 % is supplied by aerobic processes; therefore, the eye needs the highest possible amount of oxygen and sufficient glucose which can be obtained from external air and to a lesser degree from within the anterior chamber. If the oxygen supply is too low this results in hypoxic edema. Fitting athletes with contact lenses must still be viewed with caution as the visual needs of athletes are usually much more demanding than those of the general public. An indiscriminate choice of lens design can adversely affect athletic performance and may even create a hazardous situation. An intelligent choice of contact lens can provide some subtle advantages that may improve athletic performance and provide the decisive margin for victory.

  6. 3D map of the human corneal endothelial cell

    PubMed Central

    He, Zhiguo; Forest, Fabien; Gain, Philippe; Rageade, Damien; Bernard, Aurélien; Acquart, Sophie; Peoc’h, Michel; Defoe, Dennis M.; Thuret, Gilles

    2016-01-01

    Corneal endothelial cells (CECs) are terminally differentiated cells, specialized in regulating corneal hydration and transparency. They are highly polarized flat cells that separate the cornea from the aqueous humor. Their apical surface, in contact with aqueous humor is hexagonal, whereas their basal surface is irregular. We characterized the structure of human CECs in 3D using confocal microscopy of immunostained whole corneas in which cells and their interrelationships remain intact. Hexagonality of the apical surface was maintained by the interaction between tight junctions and a submembraneous network of actomyosin, braced like a drum. Lateral membranes, which support enzymatic pumps, presented complex expansions resembling interdigitated foot processes at the basal surface. Using computer-aided design and drafting software, we obtained a first simplified 3D model of CECs. By comparing their expression with those in epithelial, stromal and trabecular corneal cells, we selected 9 structural or functional proteins for which 3D patterns were specific to CECs. This first 3D map aids our understanding of the morphologic and functional specificity of CECs and could be used as a reference for characterizing future cell therapy products destined to treat endothelial dysfunctions. PMID:27381832

  7. Theoretical and numerical analysis of the corneal air puff test

    NASA Astrophysics Data System (ADS)

    Simonini, Irene; Angelillo, Maurizio; Pandolfi, Anna

    2016-08-01

    Ocular analyzers are used in the current clinical practice to estimate, by means of a rapid air jet, the intraocular pressure and other eye's parameters. In this study, we model the biomechanical response of the human cornea to the dynamic test with two approaches. In the first approach, the corneal system undergoing the air puff test is regarded as a harmonic oscillator. In the second approach, we use patient-specific geometries and the finite element method to simulate the dynamic test on surgically treated corneas. In spite of the different levels of approximation, the qualitative response of the two models is very similar, and the most meaningful results of both models are not significantly affected by the inclusion of viscosity of the corneal material in the dynamic analysis. Finite element calculations reproduce the observed snap-through of the corneal shell, including two applanate configurations, and compare well with in vivo images provided by ocular analyzers, suggesting that the mechanical response of the cornea to the air puff test is actually driven only by the elasticity of the stromal tissue. These observations agree with the dynamic characteristics of the test, since the frequency of the air puff impulse is several orders of magnitude larger than the reciprocal of any reasonable relaxation time for the material, downplaying the role of viscosity during the fast snap-through phase.

  8. Suspended onion particles and potential corneal injury in onion harvesters.

    PubMed

    Hwang, Yaw-Huei; Chou, En-Ju; Chang, Ching-Wen; Chen, Chih-Chieh; Ho, Chi-Kung; Chou, Chih-Liang; Lee, Zhih-Young; Tseng, Chi-Ting

    2002-01-01

    The authors suspected that suspended onion particles contributed to corneal ulcers in onion harvesters in southern Taiwan. In the present study, the authors used manikins to study suspended onion particles in fields in an effort to simulate typical conditions experienced by onion harvesters. An animal eye-exposure simulation study was also performed by the authors, who impacted suspended soil grains or onion particles onto the corneas of guinea pigs via aerosol generated from the Palas dispersion nozzle. The average size of 25.9 pm for suspended particles collected during the digging of onions was the largest one of those for various harvesting activities. Some onion skin flakes were found in samples obtained from gathering and packing activities; the typical flake size was approximately 3.5 x 2.5 mm2. The results of the animal study indicated that the size of soil grains has a demonstrable effect on the severity of corneal injury (p = .009). With respect to onion skin flakes, wind velocity was also associated significantly with the occurrence of corneal injury (p = .0004). A wind velocity threshold of 7 m/sec is recommended for the maintenance of safety, and if the wind speed exceeds this threshold level, workers should not engage in harvesting activities. Furthermore, use of appropriately designed goggles is necessary for the protection of onion harvesters who work in high-wind conditions.

  9. Corneal thickness in dry eyes in an Iraqi population

    PubMed Central

    Ali, Noora Mauwafak; Hamied, Furkaan M; Farhood, Qasim K

    2017-01-01

    Background Dry eye disorder is a multifactorial disease of the tears and ocular surface that results in discomfort and visual disturbance. Corneal pachymetry becomes increasingly important in refractive surgery, for the accurate assessment of intraocular pressure, and in the preoperative assessment of other ocular surgeries. Purpose To assess the effect of dry eye disorder on the central corneal thickness (CCT) by comparing with CCT of normal eyes of age-matched individuals. Patients and methods The total number of eyes examined was 280 (140 dry eyes from 70 patients and 140 normal eyes from 70 individuals). Pentacam (Scheimpflug imaging system) was used for measuring the CCT of all eyes. Results Patients with dry eye syndrome had significantly lower CCT compared to the control group (P<0.01). Its mean was 536.5 versus 561.3, respectively. Conclusion CCT of dry eyes was significantly reduced when compared with age- and gender-matched population. This result can be attributed to chronic desiccation by the inflammatory mediators in dry eyes, leading to corneal thinning. PMID:28260857

  10. Corneal topography reinterpretation through separate analysis of the projected rings

    NASA Astrophysics Data System (ADS)

    Espinosa, Julian; Roig, Ana B.; Mas, David; Hernández, Consuelo; Illueca, Carlos

    2012-06-01

    We present a new algorithm to process captured images of reflected Placido rings. Up to our knowledge, conventional topographers transform from Cartesian to polar coordinates and vice-versa, thus extrapolating corneal data and introducing noise and image artefacts. Moreover, captured data are processed by the device according to proprietary algorithms and offering a final map of corneal curvature. Corneal topography images consists of concentric rings of approximately elliptical shape. Our proposal consists of considering the information that provides each separate ring. A snake-annealing-like method permits identifying the ring even with discontinuities due to eye-lashes and reflections. By analysing the geometrical parameters of rings (centre, semi-axis and orientation), one can obtain information about small morphological micro-fluctuations and local astigmatisms. These parameters can be obtained with sub-pixel accuracy so the method results of high precision. The method can be easily adapted to work on any topographer, so that it can provide additional information about the cornea at no additional cost.

  11. Accuracy of the PAR corneal topography system with spatial misalignment.

    PubMed

    Belin, M W; Zloty, P

    1993-01-01

    The PAR Corneal Topography System is a computerized corneal imaging system which uses close-range raster photogrammetry to measure and produce a topographic map of the corneal surface. Raster photogrammetry is a standard method of extracting object information by projecting a known pattern onto an object and recording the distortion when viewed from an oblique angle. Unlike placido disc based videokeratoscopes, the PAR system requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. We studied both the accuracy of the system with purposeful misalignment (defocusing) of the test object and determined the ability to image freshly deepithelialized, keratectomized, and photoablated corneas. The PAR system was both accurate and reproducible in imaging calibrated spheres within a defined zone in space. Whole cadaver eyes were imaged both before and immediately after removal of the epithelium, lamellar keratectomy, and laser photoablation. The system demonstrated the ability to image irregular, deepithelialized, and keratectomized corneas. The ability to maintain accuracy without precise alignment and the facility to image freshly deepithelialized and keratectomized corneas may make the system suitable for intraoperative refractive monitoring.

  12. A portable microkeratome for harvesting the human anterior corneal surface.

    PubMed

    Sarayba, Melvin A; Tungsiripat, Tulaya; Sweet, Paula M; Chuck, Roy S

    2004-07-01

    A portable, gas-driven turbine microkeratome device capable of harvesting the entire anterior corneal surface for lamellar transplantation on human donor globes was evaluated. The device consisted of a modified LASIK microkeratome with an enlarged suction ring, head, and blade. Vacuum was achieved by a simple hand pump. Lamellar keratectomy was performed on 5 fresh human donor globes. Lenticule dimensions were measured on days 0, 3, 6, and 9 after storage in preservation media at 4 degrees C. On day 0, the obtained lenticules were 13.9 +/- 0.9 mm and 13.5 +/- 0.4 mm, vertical and horizontal diameters, respectively. The average central lenticule thickness was 152.2 +/- 52 microm. Each lenticule was uniform in thickness over 5 measurement points (P = 0.74). Repeat measurements of corneal thickness over the 9 days showed no statistically significant difference (P = 0.51). On day 9 lenticules were 14.6 +/- 0.3 mm and 14.6 +/- 0.4 mm, vertical and horizontal diameters, respectively. When day 0 was compared to day 9, vertical diameter also showed no statistically significant difference (P = 0.16), whereas horizontal diameter was significantly different (P < 0.001). This device proves to be an economical alternative to electric-powered systems for the harvest of transplantable corneal sections.

  13. Effect of Stratification on Surface Properties of Corneal Epithelial Cells

    PubMed Central

    Yáñez-Soto, Bernardo; Leonard, Brian C.; Raghunathan, Vijay Krishna; Abbott, Nicholas L.; Murphy, Christopher J.

    2015-01-01

    Purpose The purpose of this study was to determine the influence of mucin expression in an immortalized human corneal epithelial cell line (hTCEpi) on the surface properties of cells, such as wettability, contact angle, and surface heterogeneity. Methods hTCEpi cells were cultured to confluence in serum-free medium. The medium was then replaced by stratification medium to induce mucin biosynthesis. The mucin expression profile was analyzed using quantitative PCR and Western blotting. Contact angles were measured using a two-immiscible liquid method, and contact angle hysteresis was evaluated by tilting the apparatus and recording advancing and receding contact angles. The spatial distribution of mucins was evaluated with fluorescently labeled lectin. Results hTCEpi cells expressed the three main ocular mucins (MUC1, MUC4, and MUC16) with a maximum between days 1 and 3 of the stratification process. Upon stratification, cells caused a very significant increase in contact angle hysteresis, suggesting the development of spatially discrete and heterogeneously distributed surface features, defined by topography and/or chemical functionality. Although atomic force microscopy measurements showed no formation of appreciable topographic features on the surface of the cells, we observed a significant increase in surface chemical heterogeneity. Conclusions The surface chemical heterogeneity of the corneal epithelium may influence the dynamic behavior of tear film by “pinning” the contact line between the cellular surface and aqueous tear film. Engineering the surface properties of corneal epithelium could potentially lead to novel treatments in dry eye disease. PMID:26747762

  14. Cross-linking and the molecular packing of corneal collagen

    NASA Technical Reports Server (NTRS)

    Yamauchi, M.; Chandler, G. S.; Tanzawa, H.; Katz, E. P.

    1996-01-01

    We have quantitatively characterized, for the first time, the cross-linking in bovine cornea collagen as a function of age. The major iminium reducible cross-links were dehydro-hydroxylysinonorleucine (deH-HLNL) and dehydro-histidinohydroxymerodesmosine (deH-HHMD). The former rapidly diminished after birth; however, the latter persisted in mature animals at a level of 0.3 - 0.4 moles/mole of collagen. A nonreducible cross-link, histidinohydroxylysinonorleucine (HHL), previously found only in skin, was also found to be a major mature cross-link in cornea. The presence of HHL indicates that cornea fibrils have a molecular packing similar to skin collagen. However, like deH-HHMD, the HHL content in corneal fibrils only reaches a maximum value with time about half that of skin. These data suggest that the corneal fibrils are comprised of discrete filaments that are internally stabilized by HHL and deH-HHMD cross-links. This pattern of intermolecular cross-linking would facilitate the special collagen swelling property required for corneal transparency.

  15. Rapamycin Prolongs the Survival of Corneal Epithelial Cells in Culture

    PubMed Central

    Gidfar, Sanaz; Milani, Farnoud Y.; Milani, Behrad Y.; Shen, Xiang; Eslani, Medi; Putra, Ilham; Huvard, Michael J.; Sagha, Hossein; Djalilian, Ali R.

    2017-01-01

    Rapamycin has previously been shown to have anti-aging effects in cells and organisms. These studies were undertaken to investigate the effects of rapamycin on primary human corneal epithelial cells in vitro. Cell growth and viability were evaluated by bright field microscopy. Cell proliferation and cycle were evaluated by flow cytometry. The expression of differentiation markers was evaluated by quantitative PCR and Western blot. Senescence was evaluated by senescence-associated β-Galactosidase staining and by Western blot analysis of p16. Apoptosis was evaluated by a TUNEL assay. The results demonstrated that primary HCEC treated with rapamycin had lower proliferation but considerably longer survival in vitro. Rapamycin-treated cells maintained a higher capacity to proliferate after removal of rapamycin and expressed more keratin 14, N-Cadherin, DeltaNp63 and ABCG2, and less keratin 12, consistent with their less differentiated state. Rapamycin treated cells demonstrated less senescence by X-β-Gal SA staining and by lower expression of p16. Apoptosis was also lower in the rapamycin treated cells. These results indicate that rapamycin treatment of HCEC prevents the loss of corneal epithelial stem/progenitor cells to replicative senescence and apoptosis. Rapamycin may be a useful additive for ex vivo expansion of corneal epithelial cells. PMID:28054657

  16. Novel Lutein Loaded Lipid Nanoparticles on Porcine Corneal Distribution

    PubMed Central

    Liu, Chi-Hsien; Chiu, Hao-Che; Wu, Wei-Chi; Sahoo, Soubhagya Laxmi; Hsu, Ching-Yun

    2014-01-01

    Topical delivery has the advantages including being user friendly and cost effective. Development of topical delivery carriers for lutein is becoming an important issue for the ocular drug delivery. Quantification of the partition coefficient of drug in the ocular tissue is the first step for the evaluation of delivery efficacy. The objectives of this study were to evaluate the effects of lipid nanoparticles and cyclodextrin (CD) on the corneal lutein accumulation and to measure the partition coefficients in the porcine cornea. Lipid nanoparticles combined with 2% HPβCD could enhance lutein accumulation up to 209.2 ± 18 (μg/g) which is 4.9-fold higher than that of the nanoparticles. CD combined nanoparticles have 68% of drug loading efficiency and lower cytotoxicity in the bovine cornea cells. From the confocal images, this improvement is due to the increased partitioning of lutein to the corneal epithelium by CD in the lipid nanoparticles. The novel lipid nanoparticles could not only improve the stability and entrapment efficacy of lutein but also enhance the lutein accumulation and partition in the cornea. Additionally the corneal accumulation of lutein was further enhanced by increasing the lutein payload in the vehicles. PMID:25101172

  17. Decay accelerating factor is essential for successful corneal engraftment

    PubMed Central

    Esposito, Andrew; Suedekum, Brandon; Liu, Jinbo; An, Fengqi; Lass, Jonathan; Strainic, Michael G; Lin, Feng; Heeger, Peter; Medof, M. Edward

    2012-01-01

    In contrast to immune restrictions that pertain for solid organ transplants, the tolerogenic milieu of the eye permits successful corneal transplantation without systemic immunosuppression, even across a fully MHC disparate barrier. Here we show that recipient and donor expression of decay accelerating factor (DAF or CD55), a cell surface C3/C5 convertase regulator recently shown to modulate T cell responses, is essential to sustain successful corneal engraftment. Whereas wild type (WT) corneas transplanted into multiple minor histocompatibility antigen (mH), or HY disparate WT recipients were accepted, DAF’s absence on either the donor cornea or in the recipient bed induced rapid rejection. Donor or recipient DAF deficiency led to expansion of donor-reactive IFN-γ producing CD4+ and CD8+ T cells, as well as inhibition of antigen induced IL-10 and TGF-β, together demonstrating that DAF deficiency precludes immune tolerance. In addition to demonstrating a requisite role for DAF in conferring ocular immune privilege, these results raise the possibility that augmenting DAF levels on corneal endothelium and/or the recipient bed could have therapeutic value for transplants that clinically are at high risk for rejection. PMID:20055803

  18. Characterizing Contact Lens–Related Corneal Infiltrates: A Pilot Study

    PubMed Central

    Jansen, Meredith E.; Situ, Ping; Begley, Carolyn G.; Boree, Danielle; Chalmers, Robin L.; Osborn Lorenz, Kathrine

    2016-01-01

    Purpose: To document the time course and resolution of contact lens–related corneal infiltrative events (CIEs) comparing slit-lamp images with anterior segment ocular coherence tomography (AS-OCT) images. Methods: Six silicone hydrogel (SiHy) soft contact lens (SCL) wearers presenting with newly diagnosed symptomatic CIEs were monitored with slit-lamp images, detailed drawings, and AS-OCT until the resolution of the CIE. A final follow-up visit was completed 4 weeks after CIE resolution to determine whether scar formation was present. Positive controls were 2 SiHy SCL wearers with established (inactive) corneal scars, and negative controls were 2 SiHy SCL wearers with clear corneas. High- and low-contrast logMAR visual acuities were measured, and subjective symptom questionnaires were completed at all visits. Results: Clinical signs, vision, and symptoms improved in tandem with the resolution of the CIEs as measured by imaging methods. Calibrated measures of infiltrate width from a slit-lamp biomicroscope appear to be similar to calibrated images from AS-OCT. Conclusions: Although further studies are needed to develop standardized procedures, AS-OCT can be a useful tool to characterize the development, progression, and resolution of corneal infiltrates as an objective measure of resolution and scar formation. PMID:27560033

  19. Neutrophil extracellular traps involvement in corneal fungal infection

    PubMed Central

    Zhao, Yingying; Zhang, Fan; Wan, Ting; Fan, Fangli; Xie, Xin; Lin, Zhenyun

    2016-01-01

    Purpose Neutrophils release neutrophil extracellular traps (NETs) when defending against invading microorganisms. We investigated the existence of NETs in fungal keratitis. Methods Fourteen patients with unilateral fungal keratitis were included. Detailed information about each patient was recorded, including (1) patient history (onset of symptoms and previous therapy), (2) ocular examination findings by slit-lamp biomicroscopy, (3) laboratory findings from direct smear examination and culture of corneal scrapings, (4) NET formation, and (5) treatment strategy and prognosis. Immunofluorescence staining was used to evaluate the existence of NETs on corneal scrapings. The relationship between the quantification of NETs and the clinical character of the fungal keratitis was identified. Results NETs were identified in all 14 patients. Patients with a higher grade of NET formation and fewer fungal hyphae always showed a good treatment response and a short course of infection. NETs were consistently found mixed with fungal hyphae in the corneal scrapings from infected patients. No statistical significance was found between the grade of NETs formed and the course of infection before presentation, and no relationship between the quantification of NETs and the size of the ulcer was found. Conclusions The results suggest that NETs are involved in fungal keratitis. The number of NETs in infected corneas may provide a tool for evaluating the prognosis for fungal keratitis. PMID:27559290

  20. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute cystitis; Acute bladder infection; Acute bacterial cystitis ... cause. Menopause also increases the risk for a urinary tract infection. The following also increase your chances of having ...

  1. Limbal Stem Cell Allografts and Corneal Transplant in a Patient with Severe Corneal Melting and Perforation due to Thermokeratoplasty and Cross-Linking Treatment Burn

    PubMed Central

    Garduño-Vieyra, Leopoldo; Gonzalez, Claudia Ruth; Hernandez-Da Mota, Sergio E.

    2012-01-01

    Purpose To report corneal stem cell allografts in a patient with a persistent epithelial defect as well as corneal melting and perforation due to severe ultraviolet light burn and thermokeratoplasty treatment for keratoconus. Methods A 21-year-old female patient with corneal melting, perforation and a persistent epithelial defect in her left eye secondary to iatrogenic treatment for keratoconus, thermokeratoplasty and cross-linking was treated with penetrating keratoplasty, using a 9.0-mm diameter corneal graft and limbal stem cell allograft implants. At the end of the procedure, subtenonian injections of a combination of bevacizumab and triamcinolone were given. Results The patient had a favorable outcome 48 h after surgery, with an improvement of symptoms and a complete corneal healing. By the third week after surgery, she had a best-corrected visual acuity of 20/60 and a clear corneal graft, which remained stable for the 9 months of follow-up. Conclusions Treatment with limbal stem cell allografts and penetrating keratoplasty in a female patient with a large corneal defect and melting in her left eye was effective. Larger studies are warranted to explore the real impact of this procedure. PMID:23185178

  2. Donor Age and Corneal Endothelial Cell Loss 5 Years after Successful Corneal Transplantation: Specular Microscopy Ancillary Study Results

    PubMed Central

    2010-01-01

    Objective To determine whether endothelial cell loss 5 years after successful corneal transplantation is related to the age of the donor. Design Multicenter, prospective, double-masked clinical trial. Participants Three hundred forty-seven subjects participating in the Cornea Donor Study who had not experienced graft failure 5 years after corneal transplantation for a moderate-risk condition (principally Fuchs’ dystrophy or pseudophakic corneal edema). Testing Specular microscopic images of donor corneas obtained before surgery and postoperatively at 6 months, 12 months, and then annually through 5 years were submitted to a central reading center to measure endothelial cell density (ECD). Main Outcome Measure Endothelial cell density at 5 years. Results At 5 years, there was a substantial decrease in ECD from baseline for all donor ages. Subjects who received a cornea from a donor 12 to 65 years old experienced a median cell loss of 69% in the study eye, resulting in a 5-year median ECD of 824 cells/mm2 (interquartile range, 613–1342), whereas subjects who received a cornea from a donor 66 to 75 years old experienced a cell loss of 75%, resulting in a median 5-year ECD of 654 cells/mm2 (interquartile range, 538–986) (P [adjusted for baseline ECD] = 0.04). Statistically, there was a weak negative association between ECD and donor age analyzed as a continuous variable (r [adjusted for baseline ECD] = −0.19; 95% confidence interval, −0.29 to −0.08). Conclusions Endothelial cell loss is substantial in the 5 years after corneal transplantation. There is a slight association between cell loss and donor age. This finding emphasizes the importance of longer-term follow-up of this cohort to determine if this relationship affects graft survival. PMID:18387408

  3. Differing Roles for TCF4 and COL8A2 in Central Corneal Thickness and Fuchs Endothelial Corneal Dystrophy

    PubMed Central

    Igo, Robert P.; Kopplin, Laura J.; Joseph, Peronne; Truitt, Barbara; Fondran, Jeremy; Bardenstein, David; Aldave, Anthony J.; Croasdale, Christopher R.; Price, Marianne O.; Rosenwasser, Miriam

    2012-01-01

    Fuchs endothelial corneal dystrophy (FECD) is the most common late-onset, vision-threatening corneal dystrophy in the United States, affecting about 4% of the population. Advanced FECD involves a thickening of the cornea from stromal edema and changes in Descemet membrane. To understand the relationship between FECD and central corneal thickness (CCT), we characterized common genetic variation in COL8A2 and TCF4, genes previously implicated in CCT and/or FECD. Other genes previously associated with FECD (PITX2, ZEB1, SLC4A11), and genes only known to affect CCT (COL5A1, FOXO1, AVGR8, ZNF469) were also interrogated. FECD probands, relatives and controls were recruited from 32 clinical sites; a total of 532 cases and 204 controls were genotyped and tested for association of FECD case/control status, a 7-step FECD severity scale and CCT, adjusting for age and sex. Association of FECD grade with TCF4 was highly significant (OR  = 6.01 at rs613872; p = 4.8×10−25), and remained significant when adjusted for changes in CCT (OR  = 4.84; p = 2.2×10−16). Association of CCT with TCF4 was also significant (p = 6.1×10−7), but was abolished with adjustment for FECD grade (p = 0.92). After adjusting for FECD grade, markers in other genes examined were modestly associated (p ∼ 0.001) with FECD and/or CCT. Thus, common variants in TCF4 appear to influence FECD directly, and CCT secondarily via FECD. Additionally, changes in corneal thickness due to the effect of other loci may modify disease severity, age-at-onset, or other biomechanical characteristics. PMID:23110055

  4. Spatiotemporal temperature profiling of corneal surface during LTK

    NASA Astrophysics Data System (ADS)

    Papaioannou, Thanassis; Maguen, Ezra I.; Grundfest, Warren S.

    2002-06-01

    Accurate prediction of LTK treatments requires refined thermal corneal models which necessitate precise input parameters. The overall objective of this study was to provide detailed information on the spatiotemporal temperature profile of the corneal surface, during in-vitro thermal keratoplasty. LTK was performed in-vitro on freshly harvested porcine eyes (N equals 16) with the Sunrise Technologies corneal shaping system (Model SUN 1000). Spatiotemporal thermal imaging of the irradiated corneas were obtained with a short wave Inframetrics thermal camera (Model PM290). Images were obtained at 8-bits resolution, with ~100 microns spatial and ~17 msec temporal resolution respectively. Treatment pattern consisted of eight spots at 6 mm zone, while lasing was conducted at settings of either 100 mJ and 15 pulses (N equals 8), or 260 mJ and 7 pulses (N equals 8). Temporal and spatial variation of the corneal surface temperatures were calculated at locations of importance to LTK. At the laser spot, temperature profiles consisted of transients coinciding approximately with the laser pulses. Maximum transient temperatures observed were 98.0+/- 4.6 degree(s)C for the high and 56.3+/- 2.6 degree(s)C for the low energy respectively. These temperature transients were superimposed on an envelope of lower-slowly varying temperatures. The maximum temperatures observed for this temperature envelope, were 51.8+/- 3.4 degree(s)C for the high and 35.4+/- 3.4 degree(s)C for the low energy respectively. The evolution of either the maximum temperature transients or the lower temperature envelope, followed exponential growth of the form: T equals A * exp(B*t). Maximum temperatures at locations 0.5 mm and 1 mm away from the laser spot, reached 25.7 degree(s)C and 23.3 degree(s)C for the low energy, and 34 degree(s)C and 25.6 degree(s)C for the high energy settings respectively. Temperature decay constants were approximately 2 to 3 sec, while the spatial temperature profile at the laser

  5. Contact-mediated control of radial migration of corneal epithelial cells

    PubMed Central

    Walczysko, Petr; Rajnicek, Ann M.

    2016-01-01

    Purpose Patients with a heterozygous mutation in the gene encoding the transcription factor, PAX6, have a degenerative corneal opacity associated with failure of normal radial epithelial cell migration across the corneal surface and a reported wound healing defect. This study investigated the guidance mechanisms that drive the directed migration of corneal epithelial cells. Methods In vivo corneal epithelial wounding was performed in adult wild-type and Pax6+/− mice, and the healing migration rates were compared. To investigate the control of the cell migration direction, primary corneal epithelial cells from wild-type and Pax6+/− mice were plated on grooved quartz substrates, and alignment relative to the grooves was assayed. A reconstructed corneal culture system was developed in which dissociated wild-type and genetically mutant corneal epithelial cells could be cultured on a de-epithelialized corneal stroma or basement membrane and their migration assayed with time-lapse microscopy. Results The Pax6+/− cells efficiently re-epithelialized corneal wounds in vivo but had mild slowing of healing migration compared to the wild-type. Cells aligned parallel to quartz grooves in vitro, but the Pax6+/− cells were less robustly oriented than the wild-type. In the reconstructed corneal culture system, corneal epithelial cells continued to migrate radially, showing that the cells are guided by contact-mediated cues from the basement membrane. Recombining wild-type and Pax6 mutant corneal epithelial cells with wild-type and Pax6 mutant corneal stroma showed that normal Pax6 dosage was required autonomously in the epithelial cells for directed migration. Integrin-mediated attachment to the substrate, and intracellular PI3Kγ activity, were required for migration. Pharmacological inhibition of cAMP signaling randomized migration tracks in reconstructed corneas. Conclusions Striking patterns of centripetal migration of corneal epithelial cells observed in vivo are

  6. Concise Review: An Update on the Culture of Human Corneal Endothelial Cells for Transplantation

    PubMed Central

    Parekh, Mohit; Ferrari, Stefano; Sheridan, Carl; Kaye, Stephen

    2016-01-01

    The cornea forms the front window of the eye, enabling the transmission of light to the retina through a crystalline lens. Many disorders of the cornea lead to partial or total blindness, and therefore corneal transplantation becomes mandatory. Recently, selective corneal layer (as opposed to full thickness) transplantation has become popular because this leads to earlier rehabilitation and visual outcomes. Corneal endothelial disorders are a common cause of corneal disease and transplantation. Corneal endothelial transplantation is successful but limited worldwide because of lower donor corneal supply. Alternatives to corneal tissue for endothelial transplantation therefore require immediate attention. The field of human corneal endothelial culture for transplantation is rapidly emerging as a possible viable option. This manuscript provides an update regarding these developments. Significance The cornea is the front clear window of the eye. It needs to be kept transparent for normal vision. It is formed of various layers of which the posterior layer (the endothelium) is responsible for the transparency of the cornea because it allows the transport of ions and solutes to and from the other layers of the cornea. Corneal blindness that results from the corneal endothelial dysfunction can be treated using healthy donor tissues. There is a huge demand for human donor corneas but limited supply, and therefore there is a need to identify alternatives that would reduce this demand. Research is underway to understand the isolation techniques for corneal endothelial cells, culturing these cells in the laboratory, and finding possible options to transplant these cells in the patients. This review article is an update on the recent developments in this field. PMID:26702128

  7. Concise Review: An Update on the Culture of Human Corneal Endothelial Cells for Transplantation.

    PubMed

    Parekh, Mohit; Ferrari, Stefano; Sheridan, Carl; Kaye, Stephen; Ahmad, Sajjad

    2016-02-01

    The cornea forms the front window of the eye, enabling the transmission of light to the retina through a crystalline lens. Many disorders of the cornea lead to partial or total blindness, and therefore corneal transplantation becomes mandatory. Recently, selective corneal layer (as opposed to full thickness) transplantation has become popular because this leads to earlier rehabilitation and visual outcomes. Corneal endothelial disorders are a common cause of corneal disease and transplantation. Corneal endothelial transplantation is successful but limited worldwide because of lower donor corneal supply. Alternatives to corneal tissue for endothelial transplantation therefore require immediate attention. The field of human corneal endothelial culture for transplantation is rapidly emerging as a possible viable option. This manuscript provides an update regarding these developments. Significance: The cornea is the front clear window of the eye. It needs to be kept transparent for normal vision. It is formed of various layers of which the posterior layer (the endothelium) is responsible for the transparency of the cornea because it allows the transport of ions and solutes to and from the other layers of the cornea. Corneal blindness that results from the corneal endothelial dysfunction can be treated using healthy donor tissues. There is a huge demand for human donor corneas but limited supply, and therefore there is a need to identify alternatives that would reduce this demand. Research is underway to understand the isolation techniques for corneal endothelial cells, culturing these cells in the laboratory, and finding possible options to transplant these cells in the patients. This review article is an update on the recent developments in this field.

  8. Hydrops Fetalis/Erythroblastosis Fetalis

    MedlinePlus

    ... to Children's Hospital Milwaukee Coming to Children's Hospital Fox Valley Billing and payments Insurance information Medical records ... and concerns Locations Children's Hospital locations Milwaukee hospital Fox Valley hospital Primary care Specialty clinics Surgicenter Community ...

  9. NK Cells Promote Th-17 Mediated Corneal Barrier Disruption in Dry Eye

    PubMed Central

    Zhang, Xiaobo; Volpe, Eugene A.; Gandhi, Niral B.; Schaumburg, Chris S.; Siemasko, Karyn F.; Pangelinan, Solherny B.; Kelly, Scott D.; Hayday, Adrian C.; Li, De-Quan; Stern, Michael E.; Niederkorn, Jerry Y.; Pflugfelder, Stephen C.; De Paiva, Cintia S.

    2012-01-01

    Background The conjunctiva contains a specialized population of lymphocytes that reside in the epithelium, named intraepithelial lymphocytes (IEL). Methodology/Principal Findings Here we characterized the IEL population prior to and after experimental desiccating stress (DS) for 5 or 10 days (DS5, DS10) and evaluated the effect of NK depletion on DS. The frequency of IELs in normal murine conjunctiva was CD3+CD103+ (∼22%), CD3+γδ+ (∼9.6%), CD3+NK+ (2%), CD3−NK+ (∼4.4%), CD3+CD8α (∼0.9%), and CD4 (∼0.6%). Systemic depletion of NK cells prior and during DS led to a decrease in the frequency of total and activated DCs, a decrease in T helper-17+ cells in the cervical lymph nodes and generation of less pathogenic CD4+T cells. B6.nude recipient mice of adoptively transferred CD4+T cells isolated from NK-depleted DS5 donor mice showed significantly less corneal barrier disruption, lower levels of IL-17A, CCL20 and MMP-3 in the cornea epithelia compared to recipients of control CD4+T cells. Conclusions/Significance Taken together, these results show that the NK IELs are involved in the acute immune response to desiccation-induced dry eye by activating DC, which in turn coordinate generation of the pathogenic Th-17 response. PMID:22590618

  10. Study of corneal epithelial progenitor origin and the Yap1 requirement using keratin 12 lineage tracing transgenic mice

    PubMed Central

    Kasetti, Ramesh Babu; Gaddipati, Subhash; Tian, Shifu; Xue, Lei; Kao, Winston W.-Y.; Lu, Qingxian; Li, Qiutang

    2016-01-01

    Key issues in corneal epithelium biology are the mechanism for corneal epithelium stem cells to maintain the corneal epithelial homeostasis and wound healing responses, and what are the regulatory molecular pathways involved. There are apparent discrepancies about the locations of the progenitor populations responsible for corneal epithelial self-renewal. We have developed a genetic mouse model to trace the corneal epithelial progenitor lineages during adult corneal epithelial homeostasis and wound healing response. Our data revealed that the early corneal epithelial progenitor cells expressing keratin-12 originated from limbus, and gave rise to the transit amplifying cells that migrated centripetally to differentiate into corneal epithelial cells. Our results support a model that both corneal epithelial homeostasis and wound healing are mainly maintained by the activated limbal stem cells originating form limbus, but not from the corneal basal epithelial layer. In the present study, we further demonstrated the nuclear expression of transcriptional coactivator YAP1 in the limbal and corneal basal epithelial cells and its essential role for maintaining the high proliferative potential of those corneal epithelial progenitor cells in vivo. PMID:27734924

  11. Efficient Generation of Human Embryonic Stem Cell-Derived Corneal Endothelial Cells by Directed Differentiation

    PubMed Central

    McCabe, Kathryn L.; Kunzevitzky, Noelia J.; Chiswell, Brian P.; Xia, Xin; Goldberg, Jeffrey L.; Lanza, Robert

    2015-01-01

    Aim To generate human embryonic stem cell derived corneal endothelial cells (hESC-CECs) for transplantation in patients with corneal endothelial dystrophies. Materials and Methods Feeder-free hESC-CECs were generated by a directed differentiation protocol. hESC-CECs were characterized by morphology, expression of corneal endothelial markers, and microarray analysis of gene expression. Results hESC-CECs were nearly identical morphologically to primary human corneal endothelial cells, expressed Zona Occludens 1 (ZO-1) and Na+/K+ATPaseα1 (ATPA1) on the apical surface in monolayer culture, and produced the key proteins of Descemet’s membrane, Collagen VIIIα1 and VIIIα2 (COL8A1 and 8A2). Quantitative PCR analysis revealed expression of all corneal endothelial pump transcripts. hESC-CECs were 96% similar to primary human adult CECs by microarray analysis. Conclusion hESC-CECs are morphologically similar, express corneal endothelial cell markers and express a nearly identical complement of genes compared to human adult corneal endothelial cells. hESC-CECs may be a suitable alternative to donor-derived corneal endothelium. PMID:26689688

  12. Application of corneal tomography before keratorefractive procedure for laser vision correction.

    PubMed

    Luz, Allan; Lopes, Bernardo; Salomão, Marcela; Ambrósio, Renato

    2016-05-01

    Ectasia after refractive surgery represents a major concern among refractive surgeons. Corneal abnormalities and preexisting corneal ectasia are the most important risk factors. Corneal topography and central corneal thickness are the factors traditionally screening for in refractive surgery candidates. Study of the anterior surface by Placido topography allows for identification of keratoconus before biomicroscopy. However, this is insufficient for the evaluation of pre-operative refractive surgery. There are cases of ectasia after laser in situ keratomilusis (LASIK) without identifiable risk factors such that there is a need to go beyond the corneal surface. A key requirement is quantifying susceptibility to corneal biomechanical instability and progression to ectasia. Tomographic indices derived from elevation maps and pachymetry spatial variation produce a Belin Ambrosio display final D index (BAD-D index), which has shown better results compared to surface curvature indices for detecting very mild forms of ectasia. A logistic regression formula, integrating age, residual stromal bed, and BAD-D (Ectasia Susceptibility Score, ESS) resulted in a significant improvement in accuracy, leading to 100% sensitivity and 94% specificity for detecting susceptible cases. A comprehensive corneal structural analysis based on corneal segmental tomography can detect susceptible corneas, which increases safety for refractive surgery patients.

  13. THz and mm-Wave Sensing of Corneal Tissue Water Content: Electromagnetic Modeling and Analysis

    PubMed Central

    Taylor, Zachary D.; Garritano, James; Sung, Shijun; Bajwa, Neha; Bennett, David B.; Nowroozi, Bryan; Tewari, Priyamvada; Sayre, James; Hubschman, Jean-Pierre; Deng, Sophie; Brown, Elliott R.; Grundfest, Warren S.

    2015-01-01

    Terahertz (THz) spectral properties of human cornea are explored as a function of central corneal thickness (CCT) and corneal water content, and the clinical utility of THz-based corneal water content sensing is discussed. Three candidate corneal tissue water content (CTWC) perturbations, based on corneal physiology, are investigated that affect the axial water distribution and total thickness. The THz frequency reflectivity properties of the three CTWC perturbations were simulated and explored with varying system center frequency and bandwidths (Q-factors). The modeling showed that at effective optical path lengths on the order of a wavelength the cornea presents a lossy etalon bordered by air at the anterior and the aqueous humor at the posterior. The simulated standing wave peak-to-valley ratio is pronounced at lower frequencies and its effect on acquired data can be modulated by adjusting the bandwidth of the sensing system. These observations are supported with experimental spectroscopic data. The results suggest that a priori knowledge of corneal thickness can be utilized for accurate assessments of corneal tissue water content. The physiologic variation of corneal thickness with respect to the wavelengths spanned by the THz band is extremely limited compared to all other structures in the body making CTWC sensing unique amongst all proposed applications of THz medical imaging. PMID:26322247

  14. CCL20, (gamma)(delta) T cells, and IL-22 in corneal epithelial healing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After corneal epithelial abrasion, leukocytes and platelets rapidly enter the corneal stroma, and CCR6 (+) IL-17(+) gamma delta T cells migrate into the epithelium. Gamma delta T-cell-deficient (TCRd(-/-)) mice have significantly reduced inflammation and epithelial wound healing. Epithelial CCL20 mR...

  15. Intranasal delivery of nanomicelle curcumin promotes corneal epithelial wound healing in streptozotocin-induced diabetic mice.

    PubMed

    Guo, Chuanlong; Li, Mengshuang; Qi, Xia; Lin, Guiming; Cui, Fenghua; Li, Fengjie; Wu, Xianggen

    2016-07-11

    Corneal nerves are mainly derived from the ophthalmic branch of the trigeminal ganglion (TG). Corneal neuropathy contributes to epithelial degenerative changes in diabetic keratopathy. Efficient drug delivery to TG may be beneficial for the treatment of diabetic keratopathy. This article described intranasal delivery of nanomicelle curcumin to correct pathophysiological conditions in TG to promote corneal epithelial/nerve wound healing in streptozotocin-induced diabetic mice. A diabetic mice model with corneal epithelium abrasion was established. Ocular topical and/or intranasal nanomicelle curcumin treatments were performed, and treatment efficacy and mechanisms of action were explored. Results showed that intranasal nanomicelle curcumin treatment promoted corneal epithelial wound healing and recovery of corneal sensation. Enhanced accumulation of reactive oxygen species, reduced free radical scavengers, increased mRNA expressions of inflammatory cytokines, and decreased mRNA expressions of neurotrophic factors in the cornea and TG neuron were observed in diabetic mice with corneal epithelium abrasions. Intranasal nanomicelle curcumin treatment effectively recovered these pathophysiological conditions, especially that of the TG neuron, and a strengthened recovery was observed with ocular topical combined with intranasal treatment. These findings indicated that intranasal curcumin treatment effectively helped promote diabetic corneal epithelial/nerve wound healing. This novel treatment might be a promising strengthened therapy for diabetic keratopathy.

  16. Active Pedicle Epithelial Flap Transposition Combined with Amniotic Membrane Transplantation for Treatment of Nonhealing Corneal Ulcers

    PubMed Central

    Zhang, Ting; Wang, Yuexin; Jia, Yanni; Liu, Dongle; Li, Suxia; Shi, Weiyun

    2016-01-01

    Introduction. The objective was to evaluate the efficacy of active pedicle epithelial flap transposition combined with amniotic membrane transplantation (AMT) in treating nonhealing corneal ulcers. Material and Methods. Eleven patients (11 eyes) with nonhealing corneal ulcer who underwent the combined surgery were included. Postoperatively, ulcer healing time was detected by corneal fluorescein staining. Visual acuity, intraocular pressure, surgical complications, and recurrence were recorded. Corneal status was inspected by the laser scanning confocal microscopy and anterior segment optical coherence tomography (AS-OCT). Results. The primary diseases were herpes simplex keratitis (8 eyes), corneal graft ulcer (2 eyes), and Stevens-Johnson syndrome (1 eye). All epithelial flaps were intact following surgery, without shedding or displacement. Mean ulcer healing time was 10.8 ± 3.1 days, with a healing rate of 91%. Vision significantly improved from 1.70 to 0.82 log MAR (P = 0.001). A significant decrease in inflammatory cell infiltration and corneal stromal edema was revealed 2 months postoperatively by confocal microscopy and AS-OCT. Corneal ulcer recurred in 1 eye. None of the patients developed major complications. Conclusion. Active pedicle epithelial flap transposition combined with AMT is a simple and effective treatment for nonhealing corneal ulcers. PMID:27830086

  17. VEGF-B promotes recovery of corneal innervations and trophic functions in diabetic mice

    PubMed Central

    Di, Guohu; Zhao, Xiaowen; Qi, Xia; Zhang, Songmei; Feng, Lu; Shi, Weiyun; Zhou, Qingjun

    2017-01-01

    Vascular endothelial growth factor (VEGF)-B possesses the capacity of promoting injured peripheral nerve regeneration and restore their sensory and trophic functions. However, the contribution and mechanism of VEGF-B in diabetic peripheral neuropathy remains unclear. In the present study, we investigated the expression and role of VEGF-B in diabetic corneal neuropathy by using type 1 diabetic mice and cultured trigeminal ganglion (TG) neurons. Hyperglycemia attenuated the endogenous expression of VEGF-B in regenerated diabetic corneal epithelium, but not that of VEGF receptors in diabetic TG neurons and axons. Exogenous VEGF-B promoted diabetic corneal nerve fiber regeneration through the reactivation of PI-3K/Akt-GSK3β-mTOR signaling and the attenuation of neuronal mitochondria dysfunction via the VEGF receptor-1 and neuropilin-1. Moreover, VEGF-B improved corneal sensation and epithelial regeneration in both normal and diabetic mice, accompanied with the elevated corneal content of pigment epithelial-derived factor (PEDF). PEDF blockade partially abolished trophic function of VEGF-B in diabetic corneal re-innervation. In conclusion, hyperglycemia suppressed endogenous VEGF-B expression in regenerated corneal epithelium of diabetic mice, while exogenous VEGF-B promoted recovery of corneal innervations and trophic functions through reactivating PI-3K/Akt-GSK-3β-mTOR signaling, attenuating neuronal oxidative stress and elevating PEDF expression. PMID:28091556

  18. ICAM-1 mediates surface contact between neutrophils and keratocytes following corneal epithelial abrasion in the mouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corneal epithelial abrasion elicits an inflammatory response involving neutrophil (PMN) recruitment from the limbal vessels into the corneal stroma. These migrating PMNs make surface contact with collagen and stromal keratocytes. Using mice deficient in PMN integrin CD18, we previously showed that P...

  19. Intranasal delivery of nanomicelle curcumin promotes corneal epithelial wound healing in streptozotocin-induced diabetic mice

    PubMed Central

    Guo, Chuanlong; Li, Mengshuang; Qi, Xia; Lin, Guiming; Cui, Fenghua; Li, Fengjie; Wu, Xianggen

    2016-01-01

    Corneal nerves are mainly derived from the ophthalmic branch of the trigeminal ganglion (TG). Corneal neuropathy contributes to epithelial degenerative changes in diabetic keratopathy. Efficient drug delivery to TG may be beneficial for the treatment of diabetic keratopathy. This article described intranasal delivery of nanomicelle curcumin to correct pathophysiological conditions in TG to promote corneal epithelial/nerve wound healing in streptozotocin-induced diabetic mice. A diabetic mice model with corneal epithelium abrasion was established. Ocular topical and/or intranasal nanomicelle curcumin treatments were performed, and treatment efficacy and mechanisms of action were explored. Results showed that intranasal nanomicelle curcumin treatment promoted corneal epithelial wound healing and recovery of corneal sensation. Enhanced accumulation of reactive oxygen species, reduced free radical scavengers, increased mRNA expressions of inflammatory cytokines, and decreased mRNA expressions of neurotrophic factors in the cornea and TG neuron were observed in diabetic mice with corneal epithelium abrasions. Intranasal nanomicelle curcumin treatment effectively recovered these pathophysiological conditions, especially that of the TG neuron, and a strengthened recovery was observed with ocular topical combined with intranasal treatment. These findings indicated that intranasal curcumin treatment effectively helped promote diabetic corneal epithelial/nerve wound healing. This novel treatment might be a promising strengthened therapy for diabetic keratopathy. PMID:27405815

  20. Effects of low-power laser irradiation on the mitosis rate of the corneal epithelium

    NASA Astrophysics Data System (ADS)

    Chen, Varda; Landshman, Nahum; Belkin, Michael

    1995-05-01

    The effect of repeated low power He-Ne laser on rabbit's corneal epithelium was studied after 3 daily sessions. Under certain irradiation parameters, low power He-Ne laser irradiation was found to change the mitotic rate in the basal layer of intact corneal epithelium. Three daily irradiations for 3 or 10 minutes increased the mitotic index while 30 minutes irradiations decreased it.

  1. The core planar cell polarity gene, Vangl2, directs adult corneal epithelial cell alignment and migration

    PubMed Central

    Findlay, Amy S.; Panzica, D. Alessio; Walczysko, Petr; Holt, Amy B.; Henderson, Deborah J.; West, John D.; Rajnicek, Ann M.

    2016-01-01

    This study shows that the core planar cell polarity (PCP) genes direct the aligned cell migration in the adult corneal epithelium, a stratified squamous epithelium on the outer surface of the vertebrate eye. Expression of multiple core PCP genes was demonstrated in the adult corneal epithelium. PCP components were manipulated genetically and pharmacologically in human and mouse corneal epithelial cells in vivo and in vitro. Knockdown of VANGL2 reduced the directional component of migration of human corneal epithelial (HCE) cells without affecting speed. It was shown that signalling through PCP mediators, dishevelled, dishevelled-associated activator of morphogenesis and Rho-associated protein kinase directs the alignment of HCE cells by affecting cytoskeletal reorganization. Cells in which VANGL2 was disrupted tended to misalign on grooved surfaces and migrate across, rather than parallel to the grooves. Adult corneal epithelial cells in which Vangl2 had been conditionally deleted showed a reduced rate of wound-healing migration. Conditional deletion of Vangl2 in the mouse corneal epithelium ablated the normal highly stereotyped patterns of centripetal cell migration in vivo from the periphery (limbus) to the centre of the cornea. Corneal opacity owing to chronic wounding is a major cause of degenerative blindness across the world, and this study shows that Vangl2 activity is required for directional corneal epithelial migration. PMID:27853583

  2. Outcomes of Phacoemulsification Using Different Size of Clear Corneal Incision in Eyes with Previous Radial Keratotomy

    PubMed Central

    Wang, Jin Da; Xiong, Ying; Li, Jing; Li, Xiao Xia; Zhao, Jing; You, Qi Sheng; Huang, Yao; Tsai, Frank; Baum, Larry; Jhanji, Vishal; Wan, Xiu Hua

    2016-01-01

    Objective To evaluate visual outcomes and complications after phacoemulsification in eyes with cataract and previous radial keratotomy (RK) cuts using different sizes of clear corneal incisions. Methods The study was a retrospective study. Thirty eyes with cataract and previous RK underwent phacoemulsification and intraocular lens (IOL) implantation. Among them 7 eyes had 8 RK cuts, 13 eyes had 12 RK cuts, and 10 eyes had 16 RK cuts. Phacoemulsification and IOL implantation were performed through a 2.0–3.2 mm clear corneal incision by a single surgeon. In the 8 RK cuts group, 3.2 mm clear corneal incisions were used in 4 eyes, and 3.0 mm clear corneal incisions were used in 3 eyes. In the 12 RK cuts group, 3.2 mm clear corneal incisions were used in 6 eyes, and 2.2 mm clear corneal incisions were used in 7 eyes. In the 16 RK cuts group, 3.2 mm clear corneal incisions were used in 5 eyes, and 2.0 mm clear corneal incisions were used in 5 eyes. Patients were followed up 1 day, 1 week, 1 month, 3 months, 6 months, 1 year, 2 years, and 3 years postoperatively and were examined for the dehiscence of RK cuts during or after the surgery, post-operative best-corrected visual acuity (BCVA), corneal astigmatism, corneal endothelial cell density and complications. Results Successful phacoemulsification with IOL implantation was performed in all eyes. No wound dehiscence was noted in any eyes with 8 or 12 RK cuts. Wound dehiscence was noted in 2 eyes with 16 RK cuts. The dehiscence of RK cuts was closed successfully by injecting an air bubble with or without viscoelastic agent into the anterior chamber at the end of surgery. During the follow-up, the cuts were well apposed in all eyes, and no new dehiscence of RK cuts was noted. At the last follow-up, mean BCVA (0.2 ± 0.18 logMAR) was better than preoperative BCVA(0.45±0.19 logMAR) (P < 0.001). There was no significant difference between the long-term preoperative and postoperative mean corneal astigmatism (P = 0

  3. Lamellar interface fluid accumulation following traumatic corneal perforation and laser in situ keratomileusis.

    PubMed

    Bushley, D Matthew; Holzinger, Karl A; Winkle, R Kevin; Le, Lam H; Olkowski, John D

    2005-06-01

    A 41-year-old man with myopic astigmatism had laser in situ keratomileusis (LASIK) in each eye in April 2002. Ten months later, he sustained a central perforating corneal injury to the right eye. One day following repair of the corneal wound, he presented with diffuse corneal epithelial microcystic edema, lamellar interface fluid accumulation, and 20/400 visual acuity. Additional sutures were placed to close a presumed posterior wound gape with complete resolution of the corneal edema and lamellar interface fluid collection. One year later, his best corrected visual acuity measured 20/20+ in the right eye. This case is the first to document lamellar interface fluid accumulation following LASIK owing to traumatic disruption of the corneal endothelium.

  4. Combined use of an amniotic membrane and tissue adhesive in treating corneal perforation: a case report.

    PubMed

    Su, C Y; Lin, C P

    2000-01-01

    We report a new method combining the use of an amniotic membrane and cyanocrylate tissue adhesive to seal a corneal perforation. A 47-year-old male suffered from an alkali injury complicated with corneal melting and perforation in the left eye. We placed an amniotic membrane of optimal size in the anterior chamber directly under the corneal perforation lesion. The cyanocrylate tissue adhesive was then applied over the perforation site and sealed successfully. Three weeks later, the tissue adhesive had dislodged. The amniotic membrane had sealed the perforated lesion and was well adhered to the surrounding corneal tissue with complete epithelial covering. Vision was 20/25 six months after the operation. The combined use of an amniotic membrane and tissue adhesive is a promising method in the treatment of corneal perforation.

  5. Lower corneal temperature in neuroleptic-treated vs. drug-free schizophrenia patients.

    PubMed

    Shiloh, Roni; Bodinger, Liron; Katz, Nachum; Sigler, Maianit; Stryjer, Rafael; Hermesh, Haggai; Munitz, Hanan; Weizman, Abraham

    2003-01-01

    Antipsychotic drugs (APDs) can decrease core body temperature in schizophrenia patients. Core temperature may correlate with corneal temperature and thus, we hypothesized that neuroleptic-treated schizophrenia patients would display lower corneal temperature compared with drug-free patients. Corneal temperature of 12 typical APD-treated and 9 drug-free male schizophrenia patients was assessed using a FLIR thermal imaging camera. The APD-treated patients exhibited substantially and significantly lower corneal temperature compared with the drug-free patients (31.57 +/- 0.98 degrees C vs. 34.55 +/- 1.65 degrees C; p < 0.0001). Our results suggest that APDs may decrease corneal/core temperature in schizophrenia patients. The relevance of this finding to the pathophysiology of schizophrenia or to the antipsychotic effect of neuroleptics merit further investigation.

  6. Optical coherence tomography-based topography determination of corneal grafts in eye bank cultivation

    NASA Astrophysics Data System (ADS)

    Damian, Angela; Seitz, Berthold; Langenbucher, Achim; Eppig, Timo

    2017-01-01

    Vision loss due to corneal injuries or diseases can be treated by transplantation of human corneal grafts (keratoplasty). However, quality assurance in retrieving and cultivating the tissue transplants is confined to visual and microbiological testing. To identify previous refractive surgery or morphological alterations, an automatic, noncontact, sterile screening procedure is required. Twenty-three corneal grafts have been measured in organ culture with a clinical spectral-domain optical coherence tomographer. Employing a biconic surface fit with 10 degrees of freedom, the radii of curvature and conic constants could be estimated for the anterior and posterior corneal surfaces. Thereupon, central corneal thickness, refractive values, and astigmatism have been calculated. Clinical investigations are required to elaborate specific donor-host matching in the future.

  7. Lumican induces human corneal epithelial cell migration and integrin expression via ERK 1/2 signaling

    SciTech Connect

    Seomun, Young; Joo, Choun-Ki

    2008-07-18

    Lumican is a major proteoglycans of the human cornea. Lumican knock-out mice have been shown to lose corneal transparency and to display delayed wound healing. The purpose of this study was to define the role of lumican in corneal epithelial cell migration. Over-expression of lumican in human corneal epithelial (HCE-T) cells increased both cell migration and proliferation, and increased levels of integrins {alpha}2 and {beta}1. ERK 1/2 was also activated in lumican over-expressed cells. When we treated HCE-T cells with the ERK-specific inhibitor U0126, cell migration and the expression of integrin {beta}1 were completely blocked. These data provide evidence that lumican stimulates cell migration in the corneal epithelium by activating ERK 1/2, and point to a novel signaling pathway implicated in corneal epithelial cell migration.

  8. Cyanoacrylate repair of laser in situ keratomileusis corneal flap perforation by a snake bite.

    PubMed

    Korn, Bobby S; Korn, Tommy S

    2005-11-01

    A 30-year-old man who had laser in situ keratomileusis (LASIK) for myopia 1 year earlier developed a corneal perforation in the left eye from a boa constrictor. The patient presented to the emergency room, and a small corneal perforation just outside the visual axis was diagnosed within the LASIK flap. Cyanoacrylate adhesive was used to close the corneal perforation. The patient went on to full visual recovery with an uncorrected visual acuity of 20/20. This is the first reported case of a penetrating corneal injury from a serpent in an eye that had LASIK. Cyanoacrylate may be used to repair small traumatic corneal perforations with a favorable visual outcome in eyes that have had LASIK.

  9. Central corneal thickness of Iraqi population in relation to age, gender, refractive errors, and corneal curvature: a hospital-based cross-sectional study

    PubMed Central

    Kadhim, Yasir Jawad; Farhood, Qasim K

    2016-01-01

    Background Central corneal thickness (CCT) is an important indicator of corneal status. Its measurement provides valid information about corneal physiological condition and possible changes associated with diseases, traumas, and hypoxia. It is an integral part for interpretation of intraocular pressure and glaucoma patient management and in prerefractive procedure assessment. Objective The aim of this study is to determine the mean CCT among a normal Iraqi population and to correlate between CCT and age, gender, refraction, and corneal curvature. Patients and methods This cross-sectional study was carried out at Ibn Al-Haitham Teaching Eye Hospital. A total of 418 eyes from 209 healthy individuals with an age range from 20 to 75 years were studied. CCT was measured by ultrasound pachymeter. Refraction was measured using an auto-refractor and confirmed by trial lenses and retinoscopy to calculate the spherical equivalent. Corneal curvature was measured using an auto-refracto-keratometer to calculate the average corneal curvature (AVK). Results The mean CCT was 543.95±32.58 μm with a range from 422 to 636 μm. CCT was not affected by gender. CCT significantly negatively correlated with age and AVK. CCT significantly positively correlated with the spherical equivalence. Conclusion and recommendation Among an Iraqi population, CCT significantly decreased with age. Myopics had significantly thinner corneas. There was weak but significant negative correlation between CCT and corneal curvature. We recommend further studies about the relationship between central corneal thickness and other ocular parameters in Iraqi population such as the axial length. PMID:27932859

  10. Congenital Corneal Endothelial Dystrophies Resulting from Novel De Novo Mutations

    PubMed Central

    Cunnusamy, Khrishen; Bowman, Charles B.; Beebe, Walter; Gong, Xin; Hogan, R. Nick; Mootha, V. Vinod

    2015-01-01

    Purpose To describe two cases of congenital corneal endothelial edema resulting from novel de novo mutations. Methods Case A patient was a 15 months old Caucasian infant and Case B patient was a 3 year old Hispanic child presenting with bilateral cloudy corneas since birth. Clinicopathological findings are presented. DNA samples were screened for mutations in candidate genes by Sanger sequencing. Results Slit-lamp examination of Case A patient revealed stromal edema and haze. Histology of keratoplasty button showed stromal thickening with loss of endothelium and thin Descemet’s membrane. Sanger sequencing established the diagnosis of congenital hereditary endothelial dystrophy (CHED) by detection of a compound heterozygous mutation in SLC4A11. The proband displayed a novel de novo frameshift mutation in one SLC4A11 allele, p.(Pro817Argfs*32), in conjunction with a maternally inherited missense mutation in SLC4A11, p.(Arg869His). Case B patient similarly presented with stromal edema and stromal haze. Histopathological analysis revealed a spongy epithelium, focal discontinuities in Bowman’s layer, stromal thickening with areas of compacted posterior stroma, variable thickness of Descemet’s membrane, and regional multilayered endothelium. Sanger sequencing found a novel de novo nonsense mutation in the first exon of ZEB1, p.(Cys7*). Conclusions To our knowledge, we present the earliest clinical presentation of posterior polymorphous corneal dystrophy resulting from a de novo mutation in ZEB1. Additionally, we present a CHED case with a thin Descemet’s membrane with a novel compound heterozygous SLC4A11 mutation. In the absence of a family history or consanguinity, de novo mutations may result in congenital corneal endothelial dystrophies. PMID:26619383

  11. Correction of low corneal astigmatism in cataract surgery

    PubMed Central

    Leon, Pia; Pastore, Marco Rocco; Zanei, Andrea; Umari, Ingrid; Messai, Meriem; Negro, Corrado; Tognetto, Daniele

    2015-01-01

    AIM To evaluate and compare aspheric toric intraocular lens (IOL) implantation and aspheric monofocal IOL implantation with limbal relaxing incisions (LRI) to manage low corneal astigmatism (1.0-2.0 D) in cataract surgery. METHODS A prospective randomized comparative clinical study was performed. There were randomly recruited 102 eyes (102 patients) with cataracts associated with corneal astigmatism and divided into two groups. The first group received toric IOL implantation and the second one monofocal IOL implantation with peripheral corneal relaxing incisions. Outcomes considered were: visual acuity, postoperative residual astigmatism, endothelial cell count, the need for spectacles, and patient satisfaction. To determine the postoperative toric axis, all patients who underwent the toric IOL implantation were further evaluated using an OPD Scan III (Nidek Co, Japan). Follow-up lasted 6mo. RESULTS The mean uncorrected distance visual acuity (UCVA) and the best corrected visual acuity (BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up the UCVA was statistically better in the patients with toric IOL implants compared to those patients who underwent implantation of monofocal IOL plus LRI. The mean residual refractive astigmatism was of 0.4 D for the toric IOL group and 1.1 D for the LRI group (P<0.01). No difference was observed in the postoperative endothelial cell count between the two groups. CONCLUSION The two surgical procedures demonstrated a significant decrease in refractive astigmatism. Toric IOL implantation was more effective and predictable compared to the limbal relaxing incision. PMID:26309869

  12. Time-gated FLIM microscope for corneal metabolic imaging

    NASA Astrophysics Data System (ADS)

    Silva, Susana F.; Batista, Ana; Domingues, José Paulo; Quadrado, Maria João.; Morgado, António Miguel

    2016-03-01

    Detecting corneal cells metabolic alterations may prove a valuable tool in the early diagnosis of corneal diseases. Nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are autofluorescent metabolic co-factors that allow the assessment of metabolic changes through non-invasive optical methods. These co-factors exhibit double-exponential fluorescence decays, with well-separated short and lifetime components, which are related to their protein-bound and free-states. Corneal metabolism can be assessed by measuring the relative contributions of these two components. For that purpose, we have developed a wide-field time-gated fluorescence lifetime microscope based on structured illumination and one-photon excitation to record FAD lifetime images from corneas. NADH imaging was not considered as its UV excitation peak is regarded as not safe for in vivo measurements. The microscope relies on a pulsed blue diode laser (λ=443 nm) as excitation source, an ultra-high speed gated image intensifier coupled to a CCD camera to acquire fluorescence signals and a Digital Micromirror Device (DMD) to implement the Structured Illumination technique. The system has a lateral resolution better than 2.4 μm, a field of view of 160 per 120 μm and an optical sectioning of 6.91 +/- 0.45 μm when used with a 40x, 0.75 NA, Water Immersion Objective. With this setup we were able to measure FAD contributions from ex-vivo chicken corneas collected from a local slaughterhouse..

  13. Differentiation of embryonic stem cells into corneal epithelium.

    PubMed

    Wang, Zhichong; Ge, Jian; Huang, Bing; Gao, Qianying; Liu, Bingqian; Wang, Linghua; Yu, Ling; Fan, Zhigang; Lu, Xiaoming; Liu, Jingbo

    2005-10-01

    Our project was to determine whether embryonic stem (ES) cells could be induced to differentiate into corneal epithelia by superficial corneoscleral limbal stroma. To achieve this goal, ES-GFP cell line D3 was pre-induced by retinoic acid (RA). The pre-induced cells were seeded on deepithelialized superficial corneoscleral slices (SCSS) to form a monolayer, and divided into three groups. Group 1 was cultured and passaged in vitro for direct detection. Group 2 was exposed to air-liquid interfaces for 10 days and implanted into the subcutaneous layer of nude mice for 2 weeks for further induction in vivo. Group 3 was cultured in vitro without any inducing factors for control. There were no teratomas found in nude mice which were implanted with differentiated ES cells after two weeks. The differentiated cells showed an appearance of epithelia both in vitro and in vivo. Expression of CK3, P63 and PCNA was detected by immunohistochemical staining in the differentiated cells in group 1 and 2. Microvillis and zonula occludens were observed on the surface of the differentiated cells under an electron microscope. In the control group, ES cells differentiated freely without any inducing factors. Most cells were shed and formed a neuronal dendrite-like structure, and a minority of cells appeared polymorphic. These results demonstrate that ES cells can differentiate into corneal epithelia on the surface of SCSS under the controlled condition. Differentiated ES cells could be used as epithelial seeding cells for the reconstruction of ocular surface and corneal tissue engineering in the future.

  14. Corneal avascularity is due to soluble VEGF receptor-1.

    PubMed

    Ambati, Balamurali K; Nozaki, Miho; Singh, Nirbhai; Takeda, Atsunobu; Jani, Pooja D; Suthar, Tushar; Albuquerque, Romulo J C; Richter, Elizabeth; Sakurai, Eiji; Newcomb, Michael T; Kleinman, Mark E; Caldwell, Ruth B; Lin, Qing; Ogura, Yuichiro; Orecchia, Angela; Samuelson, Don A; Agnew, Dalen W; St Leger, Judy; Green, W Richard; Mahasreshti, Parameshwar J; Curiel, David T; Kwan, Donna; Marsh, Helene; Ikeda, Sakae; Leiper, Lucy J; Collinson, J Martin; Bogdanovich, Sasha; Khurana, Tejvir S; Shibuya, Masabumi; Baldwin, Megan E; Ferrara, Napoleone; Gerber, Hans-Peter; De Falco, Sandro; Witta, Jassir; Baffi, Judit Z; Raisler, Brian J; Ambati, Jayakrishna

    2006-10-26

    Corneal avascularity-the absence of blood vessels in the cornea-is required for optical clarity and optimal vision, and has led to the cornea being widely used for validating pro- and anti-angiogenic therapeutic strategies for many disorders. But the molecular underpinnings of the avascular phenotype have until now remained obscure and are all the more remarkable given the presence in the cornea of vascular endothelial growth factor (VEGF)-A, a potent stimulator of angiogenesis, and the proximity of the cornea to vascularized tissues. Here we show that the cornea expresses soluble VEGF receptor-1 (sVEGFR-1; also known as sflt-1) and that suppression of this endogenous VEGF-A trap by neutralizing antibodies, RNA interference or Cre-lox-mediated gene disruption abolishes corneal avascularity in mice. The spontaneously vascularized corneas of corn1 and Pax6+/- mice and Pax6+/- patients with aniridia are deficient in sflt-1, and recombinant sflt-1 administration restores corneal avascularity in corn1 and Pax6+/- mice. Manatees, the only known creatures uniformly to have vascularized corneas, do not express sflt-1, whereas the avascular corneas of dugongs, also members of the order Sirenia, elephants, the closest extant terrestrial phylogenetic relatives of manatees, and other marine mammals (dolphins and whales) contain sflt-1, indicating that it has a crucial, evolutionarily conserved role. The recognition that sflt-1 is essential for preserving the avascular ambit of the cornea can rationally guide its use as a platform for angiogenic modulators, supports its use in treating neovascular diseases, and might provide insight into the immunological privilege of the cornea.

  15. Corneal response to rigid and hydrogel lenses during eye closure.

    PubMed

    O'Neal, M R; Polse, K A; Sarver, M D

    1984-07-01

    Corneal changes were monitored in 14 subjects following 3 hr of eye closure while wearing selected oxygen permeable rigid and hydrogel lenses. The mean increase in corneal thickness ranged from 82.5 to 29.5 microns for rigid lenses with oxygen transmissibilities (Dk/L) between 0.2 X 10(-9) and 57.0 X 10(-9) (cm/sec) (ml O2/ml X mmHg), respectively, and ranged from 82.5 to 23.5 microns for hydrogel lenses with Dk/L between 2.5 X 10(-9) and 70.0 X 10(-9) (cm/sec) (ml O2/ml X mmHg), respectively. No differences in the amount of swelling between rigid and hydrogel lenses of the same oxygen transmissibility were observed (t-test, P greater than 0.20). Combining the swelling data for both types of lenses shows that a minimum lens oxygen transmissibility of approximately 75 X 10(-9) (cm/sec) (ml O2/ml X mmHg) is necessary during eye closure to prevent contact lens induced edema. The estimated oxygen tension under a lens with this Dk/L value is 40 mmHg. Recovery of the cornea to baseline thickness follows a nonlinear time course, with the rate of dehydration decreasing as the cornea thins. For initial swelling of 40-54 microns, 55-69 microns, and 70 microns and above, the time to reach baseline thickness was 1.5, 2.0, and 2.5 hr, respectively. Effects on vision, corneal curvature, distortion, and epithelial integrity were not clinically significant during this short period of eye closure.

  16. System for quantifying the formation stages of corneal arcus

    NASA Astrophysics Data System (ADS)

    Nasution, Aulia; Fahdarina, Sally; Cahya, Deny I.

    2015-07-01

    Extensive research on interpreting the clinical signs of corneal-arcus formation and their related diagnostics potentials have found that there is a strong correlation of the arcus formation with the risk of coronary artery diseases and lipid stratification. Clinically the stages of th