The evaluation of retinal circulation in advanced diabetic retinopathy before and after panretinal laser photocoagulation by scanning laser opthalmoscope

I investigated the effects of panretinal laser photocoagulation (PRP) on the velocity of retinal circulation in diabetic retinopathy. The retinal circulation was evaluated by means of rapid serial fluorescein angiography (FAG), employing scanning laser ophthalmoscope. FAG was conducted at the rate of 30 frames per seconds in video-tape. Disc-to-macula transit time (DMTT) was defined as the parameter to evaluate the retinal circulation. Diabetic 28 eyes with advanced diabetic retinopathy were examined to measure the DMTT before and after PRP. Normal 30 eyes used as control. Mean DMTT decreased from 9.8±1.5 seconds before PRP to 8.2±1.5 seconds after PRP in 28 diabetic eyes. The value with improvement after PRP was significantly shorter than the value before PRP (p < 0.05). These values before and after PRP were significantly longer than that (3.7±0.7 seconds) in normal 30 eyes (p < 0.01). Retinal circulation is retarded in diabetic retinopathy. The retardation of retinal circulation in diabetic retinopathy improves after PRP, but the value after PRP can not recover until the control level. This study was performed to reveal therapeutic effect to panretinal laser photocoagulation (PRP) for the retardation of retinal circulation in diabetic retinopathy. I investigated the effects of PRP on the velocity of retinal circulation in patients with advanced diabetic retinopathy.