Prevalence of amblyopia and patterns of refractive error in the amblyopic children of a tertiary eye care center of Nepal.

INTRODUCTION: Refractive error is a common cause of amblyopia. OBJECTIVE: To determine prevalence of amblyopia and the pattern and the types of refractive error in children with amblyopia in a tertiary eye hospital of Nepal. MATERIALS AND METHODS: A retrospective chart review of children diagnosed with amblyopia in the Nepal Eye Hospital (NEH) from July 2006 to June 2011 was conducted. Children of age 13+ or who had any ocular pathology were excluded. Cycloplegic refraction and an ophthalmological examination was performed for all children. The pattern of refractive error and the association between types of refractive error and types of amblyopia were determined. RESULTS: Amblyopia was found in 0.7 % (440) of 62,633 children examined in NEH during this period. All the amblyopic eyes of the subjects had refractive error. Fifty-six percent (248) of the patients were male and the mean age was 7.74 ± 2.97 years. Anisometropia was the most common cause of amblyopia (p less than 0.001). One third (29 %) of the subjects had bilateral amblyopia due to high ametropia. Forty percent of eyes had severe amblyopia with visual acuity of 20/120 or worse. About twothirds (59.2 %) of the eyes had astigmatism. CONCLUSION: The prevalence of amblyopia in the Nepal Eye Hospital is 0.7%. Anisometropia is the most common cause of amblyopia. Astigmatism is the most common types of refractive error in amblyopic eyes.

Early-onset scleral and corneal ectasias following low-dose mitomycin-C-augmented trabeculectomy in a uveitic glaucoma patient.

A case of early-onset sclerolimbal ectasia following low-dose topical mitomycin C application during uveitic glaucoma surgery is reported. Intraoperative and postoperative clinical courses were consistent with sclerolimbal ectasia. Adjunctive utilization of intraoperative low-dose 0.02% mitomycin C for the management of chronic uveitic glaucoma patients who are under concomitant systemic immunosuppressive regimen may enhance the risk of subacute postoperative sclerolimbal ectasia. Mitomycin C concentrations < 0.02%, decreased scleral exposure time, and a strict informed consent policy are strongly recommended in this subset of uveitic patients.

Pathophysiology of and prophylaxis against late ahmed glaucoma valve occlusion.

PURPOSE: To understand the pathophysiology of late Ahmed Glaucoma Valve failures and devise strategies to minimize this problem. METHODS: One hundred sixty eyes that had undergone Ahmed Glaucoma Valve implants by one surgeon were retrospectively reviewed. Six eyes with late (greater than 3 months) Ahmed Glaucoma Valve occlusion requiring operative intervention were identified. Two of these eyes underwent initial successful transcameral drainage tube irrigation and four initially required Ahmed Glaucoma Valve exchange. Intraoperative images, postoperative histologic analysis, and Ahmed Glaucoma Valve handling experiments were performed. RESULTS: Two eyes with late occlusion (33%; 1.25% of total implants) were initially successfully treated with irrigation alone. A gap between the valve cover and valve body junction allowed fibrovascular ingrowth and produced valve failure ultimately in five of six eyes (83%; 3.1% of total implants). This gap could be produced by grasping the device along the center line, indenting the valve cover, and damaging the plastic rivets attaching the valve cover to the valve body. Handling the Ahmed Glaucoma Valve outside this "no touch zone" eliminated this problem. CONCLUSIONS: Leaflet adhesion has a low incidence and may be treated by transcameral drainage tube irrigation. Late onset distal occlusion is best treated by Ahmed Glaucoma Valve exchange with respect for the "no touch zone." Respecting the "no touch zone over the valve mechanism should avoid creation of gaps between the valve cover and valve body junction, which allow secondary fibrovascular ingrowth.