| Objective: Diabetic retinopathy (DR) is the general illness in eyes of diabetes mellitus. And diabetic macular edema (DME) is the major cause of visual loss in all diabetic patients. On fluorescein angiography, diabetic macular edema appears to be caused by leakage mainly from micro- aneurysms and short dilated capillary segments. There is no effective medicine for DME. Vitrectomy treats DME by removal traction of vitreous body, used for those patients who suffered from sever DME and cannot receive any benefit from laser photocoagulation. Previous reports showed that laser treatment can eliminate or alleviate DME and is the preferred therapy. Yellow laser is superior to others on macular photocoagulation. The ETDRS treatment technique has been proven effective. But some microaneurysms could not be whitened or darkened even with repeated burns. And repetitious burns to microaneurysms resulted in more risk of symptomatic scotomas and possibly of fibrosis or choroidal neovascularization. Modified ETDRS protocol works well at resolving the edema and rarely causes side effects. But it may not be as effective at closing microaneurysms as the ETDRS protocol. Diabetic patients eligible for the study were randomized to either high intensity or modified ETDRS protocol photocoagulation. Through our study we want to decide which is better for the treatment. Methods: 1 91eyes of 48 patients were assigned randomly to receive either high intensity or modified ETDRS protocol photocoagulation. Follow up examinations were performed 1, 3, 6 months. Pretreatment and post-treatment ocular examinations included visual acuity, fundus examination and fluorescein angiography. We compared the difference of visual improvement, visual loss, reduction-elimination of macular edema and closure of microaneurysms. 2 Pretreatment and 6 months after treatment central 30°visual field were examined in the two groups. A comparison of light sensitivity at fovea, central 10° were done between the two groups before and after treatment. 3 Pretreatment and 6 months after treatment m-ERG were examined in the two groups. Comparisons of b-wave amplitude density, a-wave latency and b-wave latency in ring 1 and ring 2 were done between the two groups before and after treatment. Result: 1 Comparison of visual improvement, visual loss, reduction-elimination of macular edema showed no statistical difference between the two groups (P>0.05). There were 5 eyes which still had leakage caused by microaneurysms in high intensity group, which was greatly different from 14 eyes in modified ETDRS group (P<0.05). 2 There was no statistical difference in macular light sensitivity at the fovea in both two groups before and after treatment, either between them. The mean light sensitivity at central 10°showed great difference before and after treatment in both two groups. But the mean reduction of light sensitivity has no statistical difference between them. 3 Before and after treatment there was no statistical difference in b-wave amplitude density, a-wave latency and b-wave latency in ring 1 in both two groups, either between the two groups. The b-wave amplitude density, a-wave latency and b-wave latency showed great difference before and after treatment in both two groups, however, the degree changed of them has no statistical difference between the two groups. Conclusions: 1 High intensity to microaneurysms near macular laser photocoagulation for diabetic macular edema is equivalent to modified ETDRS protocol, but the former is better in closing microaneurysms. 2 There is no significant difference about the efficiency on macular function between high intensity to microaneurysms near macular and modified ETDRS protocol after photocoagulation. |
PDF Full Text Request