Abstract
Purpose :
There is lack of knowledge regarding longitudinal changes in the corneal endothelium in individuals with diabetes. The primary aim of the study was to examine the changes in the integrity of the corneal endothelium over four years in subjects with type 2 diabetes.
Methods :
Patients were recruited from Sankara Nethralaya-Diabetic Retinopathy Epidemiology and Molecular Genetic Study, a population-based follow-up study; 726 phakic subjects with a confirmed diagnosis of diabetes, with no corneal abnormalities/uveitis/glaucoma, and with no history of ocular surgeries, were examined once at baseline and after four years. Corneal endothelial hexagonality (HE%) (a measure of cell shape), coefficient of variation (CV%) (a measure of cell size) and central corneal thickness (CCT) were assessed in right eyes using noncontact specular microscopy and ultrasound pachymetry, respectively. Secondary analysis included univariate and step-wise multiple regression for assessing various clinical and biochemical factors associated with the change in corneal parameters over four years.
Results :
The mean CV of cell size was higher (35.49 vs. 36.58, p<0.001) and HE was lower at follow-up (56.20 vs 53.82, p<0.001) when compared with baseline. The difference in mean cell density (-8.01, p=0.523) and CCT (1.41, p=0.091) from baseline to follow-up was not significant. An increase in the vibration perception threshold in the distal leg (a measure of severity of peripheral neuropathy) over four years was associated with a decrease in HE (p=0.018) when adjusted for age, sex, diabetes duration, history of smoking and alcohol intake, insulin use, presence of diabetic retinopathy at baseline, and changes in HbA1c levels, refractive error, axial length, blood pressure, and serum lipid levels. Changes in CV was not associated with any of the variables examined.
Conclusions :
Small but significant corneal endothelial abnormalities in cell size and shape are evident in subjects with type 2 diabetes over four years. These abnormalities appear to be largely related to increasing severity of neuropathy, independent of age, diabetes duration, glycemic levels or diabetic retinopathy. The clinical significance of these findings necessitates further investigation.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.