Background:The purpose of our research was to investigate the effect of supplementation with vitamin C and E on ocular surface cytology specimens and related parameters in diabetic patients.Material/Methods: 60 patients were enrolled in the study. The patients were given vitamin C (1000 mg/day) and vitamin E (400 IU/day) for 10 days. Conjunctival brush cytology specimens were obtained before and after treatment. Schirmer tests, break-up time and ocular ferning tests were also performed.Results: Goblet cell densities were 50 cells/per field before and 59 cells/per field after supplementation (p=0.002). The stage of squamous metaplasia was 1.12±0.42 before and 0.88I0.41 after supplementation (p=0.011). The changes were accompanied with improved values for the Schirmer test (p<0.001), break up time (p=0.001), and ocular ferning (p<0.001).
Conclusions: Diabetes mellitus is associated with increased oxidative stress. Our study suggests that supplementation with antioxidant vitamins C and E probably plays an important role in improving the ocular surface milieu.

Keywords: Diabetes Mellitus, Type 2 - drug therapy, Antioxidants - metabolism, Ascorbic Acid - therapeutic use, Conjunctiva - drug effects, Conjunctival Diseases - pathology, Diabetes Mellitus, Type 2 - drug therapy, Goblet Cells - metabolism, Tears - drug effects, Time Factors, Vitamin E - therapeutic use