Objectives: To compare the total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI) in the aqueous humour of cataract patients with and without type 2 diabetes mellitus (T2DM).
Study design: Cross-sectional analytical study. Place and Duration of the Study: Department of Physiology, Army Medical College, National University of Medical Sciences, Rawalpindi, Pakistan in collaboration with Armed Forces Institute of Ophthalmology, from 1st June 2022 to 31st January 2023.
Methodology: A total of 120 individuals were recruited and divided into 2 equal groups. Sample of aqueous humour was collected, and the total oxidant status, and total antioxidant status were measured by spectrophotometry. Blood samples were collected to measure the fasting glucose and glycosylated haemoglobin levels. Results were analysed by SPSS version 24 and p-value ≤0.05 was considered significant.
Results: Total oxidative stress and OSI were (55.57±5.46) vs. (33.75±4.28) = p (0.001), (32.79±9.23) vs. (13.28±3.02) = p (0.001) found significantly increased in aqueous humour of diabetic patients while TAC was reduced (1.86±0.41) vs. (2.62 ± 0.45) = p (0.001) compared to the non-diabetics. Fasting blood glucose (109.18±12.32 vs. 91.61±5.71 mg/dl, p=0.001) and glycosylated haemoglobin levels (6.46±0.85 vs.5.43±0.85, p=0.001) were also found significantly high in the diabetic group compared to the non-diabetics.
Conclusion: Increased levels of glucose and glycosylated haemoglobin increase oxidative stress in the blood of T2DM patients. This raises the total oxidative stress in the aqueous homor while lowering the TAC. This disturbed oxidant-antioxidant status in the aqueous humour of diabetic patients plays an important role in the development of cataract in T2DM patients compared to non-diabetics.
Key words: Cataract, Aqueous humour, Oxidative stress, Type 2 diabetes mellitus.