Dry eye and visual function in young adult diabetics

Abstract

The escalating prevalence of diabetes in the world, and in Malaysia particularly is a concern. Limited studies have linked the dry eye status in the young adult diabetic population using standardised questionnaire with standard tear film function and clinical tests, and the more subtle aspects of visual function.This thesis presents two studies relating to the use of a localized version of the standard questionnaire in elucidating dry eye symptoms in relation to the other clinical tests used in dry eye diagnosis, and in relation to best corrected visual acuity, contrast sensitivity and colour vision, in young diabetics.The first study validated the translated version of Ocular Symptom Disease Index (OSDI) in Bahasa Malaysia, referred to as the OSDI-Bahasa; an instrument meant to overcome the difficulties in responding to the questionnaire in English for some Malaysians who are not fluent in the English language. The original OSDI was translated and transformed into an online questionnaire using JotForm program and was distributed to 195 bilingual participants to assess its reliability. The Cronbach’s alpha values for each item in the questionnaire ranged from 0.88 to 0.94. Factor analysis revealed that 12 items in OSDI-Bahasa clustered together to create three latent subscales which were vision-related function, ocular symptoms and environment triggers. For repeatability, the OSDI-Bahasa score in 23 subjects were compared after a week. There was no significant difference between the two sessions (p = 0.692). The OSDI-Bahasa was found to be both reliable and repeatable. The second (main) study investigated dry eye symptoms scores (as determined by the OSDI-Bahasa validated in the first study), clinical tests of dry eye (Phenol red thread, tear break up time, corneal staining, Marx line displacement, meibomian gland count and meibomian gland quality) and visual functions (visual acuity, contrast sensitivity and colour vision) in 37 young (age range: 19 to 39 years) adult patients with diabetes mellitus, comparing these measures with a similar age range as controls. The main inclusion criterion was diagnosed diabetes without any other ocular diseases. The results obtained for the diabetic group without significant diabetic retinopathy, were not significantly different from the control group in all parameters. Multiple regression analysis revealed contrast sensitivity as a significant predictor of dry eye symptoms in diabetics, accounting for 46.5% of the variance in OSDI (p=0.006). It is concluded that contrast sensitivity is a predictor of dry eye symptoms in young adult diabetics within this population, having been shown also as a sensitive measure of subclinical visual changes in the said population.