To investigate the result of posterior sub-tenon triamcinolone acetonide injection combined with panretinal photocoagulation (PRP) in patients with diabetic retinopathy.

A prospective study was performed on patients with diabetic retinopathy who required PRP. The study group consisted of 12 patients (12 eyes) of diabetic retinopathy without clinically significant macular edema (CSME) and 13 patients (13 eyes) with CSME. All patients were injected posteriorly with sub-tenon triamcinolone acetonide (40 mg) one week before PRP. During a six-month follow-up, best-corrected visual acuity, the development of macular edema, changes in fluorescein angiography, and related complications were monitored.

During a six-month follow-up, visual acuity was well preserved in patients with diabetic retinopathy without CSME (12 eyes). Only one patient in this group experienced temporary macular edema at 3 months after combined therapy. In the CSME group (13 eyes), the visual acuities of seven patients (53.8%) increased,those of five patients (38.5%) remained same, and one patient's visual acuity (7.7%) decreased in a study period of six months. Fluorescein angiography showed that macular edema was resolved in most patients except in one patient in whom macular edema remained for up to 6 months. Complications from combined therapy occurred in two patients who showed slight and temporary increase of intraocular pressure.

Combined treatment with posterior sub-tenon triamcinolone acetonide injection and PRP may provide benefits for patients with diabetic retinopathy who require urgent PRP by preventing exacerbation of macular edema.