Changes of total antioxidant capacity and total oxidant status of aqueous humor in diabetes patients and correlations with diabetic retinopathy

AIM: To measure changes of total oxidant status (TOS) and total antioxidant capacity (TAC) of aqueous humor (AH) in diabetic retinopathy (DR) patients, and to determine if there were any differences in TOS and TAC of AH in diabetic patients without retinopathy com pared with non-diabetic patients. METHODS: One hundred and three eyes of 1 03 patients who were enrolled for cataract surgery were included in this study. Patients were grouped according to presence of diabetes and stage of DR. Prior to cataract surgery, 0.1 mL to 0.2mL of AH was aspirated and analyzed for TAC and TOS level using a colorim etric method. RESULTS: TOS levels were highest among proliferative diabetic retinopathy (PDR) patients and lowest in patients with only cataracts. Results were statistically significant between all groups (P<0.05). Whereas result between diabetic without retinopathy patients and non-proliferative diabetic retinopathy (NPDR) patients was not statistically significant (P=0.757). TAC levels were highest in patients with only cataract and lowest among PDR patients and results were statistically significant between all groups (P<0.05). CONCLUSION: Aqueous hum or TAC levels are low in diabetic patients and reduced further in DR patients, TOS levels are increased in diabetic patients and this is exacerbated in DR patients.