Objective: To evaluate the clinical effects of krypton yellow laser photocoagulation for cystoid macular edema (CME) in nonproliferative diabetic retinopathy (NPDR).
Methods: 52 eyes (37 cases) with CME in NPDR were treated with local or grid macular krypton yellow photocoagulation, and according to the course they were divided into two groups: group I (<or= 6 months) and group II (>or= 7 months). The follow-up was 1 year. The visual acuity and the degree of macular edema in various period were analyzed and compared.
Results: The mean visual acuity was 0.27 +/- 0.21 before treatment and 0.53 +/- 0.26 after treatment (P < 0.01), 90.4% was increased, 5.8% was stable and 3.8% was decreased. CME disappeared completely in 55.8% of the patients, disappeared partially in 42.3% and stable in 1.9%. In group I the visual acuity was improved in 81.5% of the patients at post-treatment 1 month; at post-treatment 6 months, the visual acuity was increased in 100% of the cases, CME disappeared completely in 70.4% and disappeared partially in 29.6%. In group II, the visual acuity was improved in 20% of the patients at post-treatment 1 month, and at post-treatment 6 months in 88%, CME disappeared completely in 40% and disappeared partially in 56%. The differences in the rate of visual recovery and therapeutic effects between the two groups were statistically significant (P < 0.01).
Conclusions: Krypton yellow laser is prominently effective and selective for CME in NPDR. The effects are related to the course of the disease, and the therapeutic results are better in cases receiving early treatment.