Abstract
Abstract: :
Purpose: To assess emaciation of the retinal nerve fiber layer (RNFL) in diabetic patients by a scanning laser polarimeter (GDx VCC). Methods: One eye of 48 patients with type 2 diabetes mellitus was subclassified into 3 groups: Group 1; eyes without diabetic retinopathy, but with a known history of DM > 6 years. Group 2; eyes with simple diabetic retinopathy. Group 3; eyes with preproliferative and proliferative retinopathy. And the data were compared with 36 control subjects. Age and refractive error were matched between control and simple diabetic retinopathy eyes. Studied parameters includes scanning laser polarimetric parameters (TSNIT average, superior and inferior average, TSNIT standard deviation and NFI), duration of DM, HbA1c, IOP, creatinine, hypertension >150 mmHg, vitrectomy, and photocoagulation. Eyes with a known history of diabetic optic neuropathy, extensive macular degeneration, bleeding or hard exudation were excluded. Results: Two types (diffuse and focal) of RNFL defects were found in diabetic patients. Thickness of the retinal nerve fiber layer decreased in an early stage of diabetes. The average thickness in the inferior meridian was significantly less than that of the control subjects before an appearance of retinal angiopathy. The mean thickness of the retinal nerve fiber layer decreased with an increase in severity of the diabetic retinopathy. Conclusions: The emaciation of the RNFL appears before an appearance of diabetic retinal angiopathy. The reduction in retinal nerve fiber layer paralleled severity of diabetic retinopathy. Reduction of the RNFL in diabetic patients
P: comparison with control eyes; Student t–test DMR: diabetic retinopathy, PDR; proliferative diabetic retinopathy, Pre–Prol; preproliferative diabetic retinopathy, TSNIT; temporal–superior–nasal–inferior–temporal, STD; standard deviation
Keywords: diabetes • imaging/image analysis: clinical • nerve fiber layer