Retinal sensitivity in subjects with type 2 diabetes mellitus: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study (SN-DREAMS II, Report No. 4).

AIM: To evaluate retinal sensitivity (RS) in subjects with diabetes in a population-based study and to elucidate associated risk factors for abnormal RS. METHODS: A subset of 357 subjects from Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study-II was included in this study. All subjects underwent detailed ophthalmic evaluation including microperimetry and spectral domain optical coherence tomography. RESULTS: The prevalence of abnormal mean retinal sensitivity (MRS) was 89.1%. MRS was significantly reduced in subjects with diabetes but no retinopathy when compared with non-diabetic subjects. MRS was reduced in moderate non-proliferative diabetic retinopathy (DR) and macular oedema (ME) at 8° (p=0.04, p=0.01, respectively) and in ME at 10° (p=0.009) and 12° (p=0.036) compared with no DR. Significant negative correlation was found between MRS and best corrected visual acuity, duration of diabetes, glycosylated haemoglobin and central foveal thickness. Increased retinal thickness remained a significant risk factor (OR, 1.02; p=0.044) for abnormal MRS. Altered inner retinal layers and foveal contour were associated with reduced MRS among subjects with DR and presence of epiretinal membrane, altered foveal contour and altered retinal pigment epithelium were associated with reduced MRS. CONCLUSIONS: Reduced RS in those subjects with diabetes but no retinopathy suggests the early neuronal damage in type 2 diabetes mellitus.

Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study (SN--DREAMS III): study design and research methodology.

BACKGROUND: To describe the methodology of the Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III, an ongoing epidemiological study to estimate the prevalence of diabetes and diabetic retinopathy in rural population of Kanchipuram and Thiravallur districts of Tamil Nadu, India and to elucidate the clinical, anthropometric, biochemical and genetic risk factors associated with diabetic retinopathy in this rural population. METHODS: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Study III will be a mobile van based epidemiological study; 11,760 participants aged ≥ 40 years will be recruited from the study areas. Eligible subjects will undergo blood sugar estimation to diagnose diabetes.Oral glucose tolerance test will be done to conform diabetes. All subjects with diabetes will undergo complete information of knowledge, aptitude and practice of diabetes and diabetic retinopathy, Diet questionnaire, demographic data, socioeconomic status, physical activity, anthropometric measurements, and risk of sleep apnoea. A detailed medical and ocular history, a comprehensive eye examination including refraction, slit lamp biomicroscopy examination, indirect ophthalmoscopy, slit lamp biomicroscopy, digital stereo fundus photography and ultrasound of eye will be done in the mobile van. Blood will be collected for biochemical investigations including blood hemoglobin, glycosylated hemoglobin, lipid profile, urea and creatinine, genetic study. Urine will be collected for microalbuminuria. All fundus photographs will be graded at base hospital. Participants who need treatment will be sent to the base hospital. A computerized database is created for the records. CONCLUSION: The study is expected to provide an estimate of the prevalence of diabetes and diabetic retinopathy and also a better understanding of the genetic, anthropometric and socio-economic risk factors associated with diabetic retinopathy in a rural South Indian population.

Rhegmatogenous retinal detachment following treatment for retinoblastoma.

PURPOSE: To elucidate characteristics of rhegmatogenous retinal detachment that developed in children who underwent treatment for retinoblastoma and to analyze the outcome following vitreoretinal surgery in such clinical settings. METHODS: This was a retrospective case series of 9 eyes of 9 patients who underwent vitreoretinal surgery for tumor control and retinal reattachment. RESULTS: At the time of diagnosis of rhegmatogenous retinal detachment, retinoblastoma was regressed in 6 eyes (67%). The retinal detachment involved less than two quadrants in 7 eyes (78%) and was caused by an atrophic break in 7 eyes. Seven eyes underwent a non-drainage scleral buckling procedure. Three eyes underwent vitreous surgery; in 2 of these eyes, tumor excision along with retinectomy using melphalan infusion was performed and eventually silicone oil tamponade was used. Retinal reattachment was achieved in all eyes with eventual tumor control in 7 eyes. The median follow-up after retinal reattachment surgery was 24 months. CONCLUSION: Rhegmatogenous retinal detachment in treated eyes with retinoblastoma is usually caused by an atrophic retinal break. Retinal detachment can be repaired successfully in most eyes.