OXIDATIVE RETINAL PRODUCTS AND OCULAR DAMAGES IN DIABETIC-PATIENTS

Several evidences suggest a retinal participation to the genesis of di abetic eye complications by means of an increased free radical product ion at this level. However, no direct proof exists that this happens i n humans in vivo. Therefore, the concentrations of malondialdehyde (MD A), carbonyl and sulfhydryl (P-SH) proteins, and vitamin E have been a ssessed in the subretinal fluid (SF) of patients affected by retinal d etachment. Diabetic (n = 19) and nondiabetic (n = 21) subjects with co mparable age, degree of myopia, and duration of the retinal detachment were considered. A control group of n = 7 subjects was included. The SF was collected after drainage during surgery. The concentrations of total proteins, P-SH, and carbonyl proteins were determined with spect rophotometric methods; the levels of MDA and vitamin E were measured b y HPLC. The protein concentration in SF did not differ among groups. A higher concentration of MDA (p <.01) and carbonyl proteins (p <.02) w ere found in diabetic compared to nondiabetic subjects. Diabetic patie nts also showed a lower content of P-SH (p <.002) and vitamin E (p <.0 01) compared to nondiabetic subjects. All these parameters were more m arkedly altered in patients affected by proliferative diabetic retinop athy and significantly differed between patients and control subjects. In conclusion, oxidative events are associated with retinal detachmen t in humans. This evidence strongly suggests that the retina is a sour ce of free radical production under certain conditions, such as diabet es, (C) 1998 Elsevier Science Inc.