Abstract
Abstract: :
Purpose: To compare Subthreshold Micropulse Diode Laser Photocoagulation (SMDLP) with Conventional Argon Laser Photocoagulation (CLP) in the treatment of diabetic clinically significant macular edema (CSME). Methods: An ongoing prospective pilot study involving diabetic patients with CSME randomized into two groups – SMDLP group (patients receive subthreshold micropulse laser) and CLP group (patients receive conventional Argon laser). Twenty eyes of 16 diabetic phakic patients have been included in the study. Seventeen eyes have had 4 or more months of follow-up. CSME is defined as per ETDRS criteria. Best-corrected visual acuity (BCVA) is measured with ETDRS chart and converted to LogMAR. Evaluation of CSME was based on clinical evaluation and fluorescein angiogram. The laser settings in SMDLP group were: spot size 75µm, micropulse mode 5%-15% (burn duration 0.1-0.3 msec, interval duration 1.7-1.9 msec), envelope duration 200-400 msec, power 600 to 1500 mW and number of burns ranged from 103 to 410. The laser settings in CLP group were: spot size 50 - 100 µm, duration 50-75 msec, power 80 to 140 mW and number of burns ranged from 43 to119. Results: 10 eyes received SMDLP and 10 eyes received CLP. At baseline, mean BCVA in SMDLP and CLP was 0.05 and 0.14 LogMAR respectively. Final mean BCVA in SMDLP and CLP was 0.05 and 0.13 LogMAR respectively. In SMDLP group, seven eyes had 4 months of follow-up. Six out of 7 eyes (85.7%) had persistent macular edema at 4 month visit and have been retreated. In one out of 7 eyes (14.3%), CSME resolved after the first treatment. In CLP group, 10 eyes have had 4 or more months of follow-up. Six out of 10 eyes (60%) had persistent CSME at 4 month visit and have been re-treated. In four out of 10 eyes (40%), CSME resolved at 4 (2 eyes) and 8 (2 eyes) months of follow up. Conclusion: Subthreshold Micropulse Diode Laser Photocoagulation in diabetic patients with clinically significant macular edema can cause resolution of macular edema and stabilization of visual acuity. Results of a larger series of patients are underway.
Keywords: macula/fovea • laser • diabetic retinopathy