To investigate the clinical effect and complications of patterned scanning laser photocoagulation with short exposure time in diabetic retinopathy.

A prospective study was performed on patients with diabetic retinopathy who required panretinal photocoagulation (PRP). Twenty-nine eyes of twenty five consecutive patients underwent patterned scanning laser photocoagulation with exposure time of 0.02 sec over the entire retina. Pain score at treatment, best-corrected visual acuity, the development of macular edema, regression of neovascularization in fluorescein angiography, and related complications were monitored during a three-month follow-up.

Treatment time for PRP was much reduced to 6.1 min on the entire retina. Pain during the photocoagulation was moderate, and enabled patients to finish PRP with ease. During a three-month follow-up, visual acuity was well preserved. Foveal minimum thickness increased at 1 month after treatment and maintained in a study period of three months. Macular volume showed significant increase (3.6%) at 1 month after treatment, maximum increase (9.8%) at 2 months, and persistent increase (4.9%) at 3 months. In every patient with very severe nonproliferative diabetic retinopathy, retina was maintained, and in 10 of 18 eyes with proliferative diabetic retinopathy, neovascularization regressed during follow-up period. No significant complication occurred except a transient vitreous hemorrhage in one eye.

Patterned scanning laser photocoagulation with short exposure time may induce transient macular edema, but the visual acuity was preserved without any other significant complication. It is considered to be a safe and efficient treatment method in diabetic retinopathy.