Quantification of collagen organization in the peripheral human cornea at micron-scale resolution

The collagen microstructure of the peripheral cornea is important in stabilizing corneal curvature and refractive status. However, the manner in which the predominantly orthogonal collagen fibrils of the central cornea integrate with the circumferential limbal collagen is unknown. We used microfocus wide-angle x-ray scattering to quantify the relative proportion and orientation of collagen fibrils over the human corneolimbal interface at intervals of 50 μm. Orthogonal fibrils changed direction 1–1.5 mm before the limbus to integrate with the circumferential limbal fibrils. Outside the central 6 mm, additional preferentially aligned collagen was found to reinforce the cornea and limbus. The manner of integration and degree of reinforcement varied significantly depending on the direction along which the limbus was approached. We also employed small-angle x-ray scattering to measure the average collagen fibril diameter from central cornea to limbus at 0.5 mm intervals. Fibril diameter was constant across the central 6 mm. More peripherally, fibril diameter increased, indicative of a merging of corneal and scleral collagen. The point of increase varied with direction, consistent with a scheme in which the oblique corneal periphery is reinforced by chords of scleral collagen. The results have implications for the cornea's biomechanical response to ocular surgeries involving peripheral incision

Immunosuppressive potential of human amnion epithelial cells in the treatment of experimental autoimmune encephalomyelitis

BACKGROUND: Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system (CNS). In recent years, it has been found that cells such as human amnion epithelial cells (hAECs) have the ability to modulate immune responses in vitro and in vivo and can differentiate into multiple cell lineages. Accordingly, we investigated the immunoregulatory effects of hAECs as a potential therapy in an MS-like disease, EAE (experimental autoimmune encephalomyelitis), in mice. METHODS: Using flow cytometry, the phenotypic profile of hAECs from different donors was assessed. The immunomodulatory properties of hAECs were examined in vitro using antigen-specific and one-way mixed lymphocyte proliferation assays. The therapeutic efficacy of hAECs was examined using a relapsing-remitting model of EAE in NOD/Lt mice. T cell responsiveness, cytokine secretion, T regulatory, and T helper cell phenotype were determined in the peripheral lymphoid organs and CNS of these animals. RESULTS: In vitro, hAECs suppressed both specific and non-specific T cell proliferation, decreased pro-inflammatory cytokine production, and inhibited the activation of stimulated T cells. Furthermore, T cells retained their naïve phenotype when co-cultured with hAECs. In vivo studies revealed that hAECs not only suppressed the development of EAE but also prevented disease relapse in these mice. T cell responses and production of the pro-inflammatory cytokine interleukin (IL)-17A were reduced in hAEC-treated mice, and this was coupled with a significant increase in the number of peripheral T regulatory cells and naïve CD4+ T cells. Furthermore, increased proportions of Th2 cells in the peripheral lymphoid organs and within the CNS were observed. CONCLUSION: The therapeutic effect of hAECs is in part mediated by inducing an anti-inflammatory response within the CNS, demonstrating that hAECs hold promise for the treatment of autoimmune diseases like MS

Bilateral disciform keratitis of presumed adenoviral etiology

Adenoviral conjunctivitis may lead to subepithelial corneal infiltrates as a late complication. Herein, we aim to present a 19-year-old healthy female, who developed bilateral disciform keratitis three weeks after suffering adenoviral conjunctivitis. She presented with widespread subepithelial corneal infiltrates in addition to central corneal edema with white distinct border resembling immune stromal ring, as well as Descemet's folds and keratic precipitates in the central area. Following topical corticosteroid and ganciclovir for 10 days, her condition improved. After 1 month, she had another episode. Short-term topical corticosteroids in addition to long-term topical cyclosporine and nonpreserved artificial tears were able to prevent further recurrences

Ischemic Retinopathy and Neovascular Proliferation Secondary to Severe Head Injury

We report a case with severe head trauma and perforating globe injury in one eye and ischemic retinopathy and neovascular proliferation in the other eye. A 37-year-old male was brought to the emergency department after a motor vehicle accident with severe maxillofacial trauma. Ophthalmic examination revealed hematoma of the left eyelids as well as traumatic rupture and disorganization of the left globe. On the right eye, anterior segment and fundoscopic examination were normal. Primary globe repair was performed. At postoperative one-month visit, the right eye revealed no pathology of the optic disc and macula but severe neovascularization in the temporal peripheral retina. The patient was diagnosed as ischemic retinopathy and neovascular proliferation due to head trauma

Surgical results of combined pars plana vitrectomy and phacoemulsification for vitreous hemorrhage in PDR

Background: The purpose of this study was to evaluate the effectiveness, safety, and incidence of complications after combined clear corneal phacoemulsification with intraocular lens implantation and pars plana vitrectomy in eyes with proliferative diabetic retinopathy coexistent with significant cataract. Methods: Eighty-five eyes of 85 patients with proliferative diabetic retinopathy underwent primary standard three-port vitrectomy with 20-gauge instruments and phacoemulsification with intraocular lens implantation for vitreous hemorrhage from 2008 to 2011. The main outcome measures were visual outcomes and surgical complications. Results: Forty patients were male and 45 were female. Their age ranged from 40 to 77 years with a mean of 59.6 years. The mean follow-up was 13 months, with a range of 6-48 months. The preoperative logMAR visual acuity changed from 2.62 ± 0.6 to 0.8 ± 0.7 postoperatively. Postoperatively, visual acuity improved in 79 eyes (92.9%), and did not change in six eyes (7.1%). Intraoperative complications were transient corneal edema (five eyes) and posterior capsular rupture (one eye). Postoperative complications consisted of transient intraocular pressure elevation (25 eyes), corneal epithelial defects (six eyes), anterior chamber reaction (four eyes), hyphema (two eyes), posterior synechiae (four eyes), vitreous hemorrhage (23 eyes), retinal tears (five eyes), retinal detachment (one eye), and neovascular glaucoma (one eye). Conclusion: Our study suggests that the combined operation of pars plana vitrectomy, phacoemulsification, and intraocular lens implantation is safe and effective for patients with proliferative diabetic retinopathy. We believe that the visual outcome and complications depended primarily on underlying posterior segment pathology and were not related to the combined procedure technique. © 2013 Canan et al

Comparison of the inhibitory effect of different doses of subconjunctival bevacizumab application in an experimental model of corneal neovascularization

AIM: To evaluate the inhibitory effect of subconjunctival bevacizumab as single- and multiple-dose application, and compare their effects on corneal neovascularization in a rat model. METHODS: Thirty adult Sprague-Dawley rats were used in this experimental study. The central cornea of the rats was cauterized chemically. The rats were randomly enrolled into three groups. All groups received subconjunctival injections. In Group 1 (control group, n=10), 0.05 mL 0.9% NaCl solution was injected on the first day. In Group 2 (single-dose group, n=10), 0.05 mL bevacizumab (1.25 mg) was injected on the first day. In Group 3 (multiple-dose group, n=10), four doses of 0.05 mL bevacizumab (1.25 mg) were injected on the first, third, fifth and seventh day. Slit-lamp examination of all rats was performed at the third and ninth day. Digital images of the corneas were taken and analyzed using image analysis software to calculate corneal neovascularization area. All rats were sacrificed on the tenth day. In corneal sections, the number of blood vessels, state of inflammation and collagen formation was evaluated histopathologically. RESULTS: In Group 3, corneal edema grades were significantly lower than Group 1 and Group 2 (P=0.02, and P=0.035, respectively). The mean percentage of neovascularized corneal area in Group 3 was significantly lower than Group 2 (P=0.005). On histopathological examination, Group 2 and Group 3 showed significantly less number of blood vessels than Group 1 (P=0.005, and P=0.001, respectively). Additionally, Group 3 showed significantly less number of blood vessels compared to Group 2 (P=0.019). Inflammation and edema grades were significantly lower in Group 3 compared to Group 1 (P=0.001). CONCLUSION: Subconjunctival bevacizumab injection is effective in inhibition of newly formed corneal neovascularization. The multiple-dose bevacizumab treatment seems to be more effective compared to single-dose treatment

Excision and cryosurgery in the treatment of conjunctival malignant epithelial tumours

Purpose To evaluate the long-term results of combined treatment with excision and cryosurgery for malignant epithelial tumours of the conjunctiva