VISUAL-FIELDS AT DIFFERENT STAGES OF DIABETIC-RETINOPATHY

Available studies on visual field disturbances in diabetic retinopathy have shown conflicting results, obtained with different and often non -comparable techniques. We have studied visual fields at different sta ges of diabetic retinopathy with modern sensitive computerized techniq ue taking precautions to limit disturbing effects of random field vari ation and lack of perimetric experience. Sixty-three diabetic patients , insulin-dependent and non-insulin dependent, were each subject to th ree test sessions using the 30-2 full threshold program of the Humphre y perimeter. Retinopathy levels ranged from 10 to 65 in the ETDRS Fina l scale. In eyes without retinopathy or with very mild and mild diseas e (levels 10-35) mean deviation values exceeding the p<5% level occurr ed in only 4% of eyes in trained sessions, and the number of test poin ts with significantly reduced sensitivity did not exceed that expected in normal eyes. In moderate and moderately severe diabetic retinopath y (levels 43-47) and in severe non-proliferative and proliferative ret inopathy (levels 53-65) there was clear evidence of field loss, howeve r, with significantly reduced mean deviation values in 44% of the eyes and 6.5% of tested points showing reproducible loss of sensitivity. T hus, there was no evidence of field loss in eyes with mild disease, bu t clear field defects in eyes with more advanced disease. Significantl y reduced sensitivity was often correlated with retinal non-perfusion and there was seen a tendency towards more correlation in the midperip hery than paracentrally.