Clinical Trials
February 9, 2009

Observational Study of the Development of Diabetic Macular Edema Following Panretinal (Scatter) Photocoagulation Given in 1 or 4 Sittings

Diabetic Retinopathy Clinical Research Network*
Author Affiliations

Anne S.LindbladPhD


Copyright 2009 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.2009

Arch Ophthalmol. 2009;127(2):132-140. doi:10.1001/archophthalmol.2008.565

Objective  To compare the effects of single-sitting vs 4-sitting panretinal photocoagulation (PRP) on macular edema in subjects with severe nonproliferative or early proliferative diabetic retinopathy with relatively good visual acuity and no or mild center-involved macular edema.

Methods  Subjects were treated with 1 sitting or 4 sittings of PRP in a nonrandomized, prospective, multicentered clinical trial.

Main Outcome Measure  Central subfield thickness on optical coherence tomography (OCT).

Results  Central subfield thickness was slightly greater in the 1-sitting group (n = 84) than in the 4-sitting group (n = 71) at the 3-day (P = .01) and 4-week visits (P = .003). At the 34-week primary outcome visit, the slight differences had reversed, with the thickness being slightly greater in the 4-sitting group than in the 1-sitting group (P = .06). Visual acuity differences paralleled OCT differences.

Conclusions  Our results suggest that clinically meaningful differences are unlikely in OCT thickness or visual acuity following application of PRP in 1 sitting compared with 4 sittings in subjects in this cohort. More definitive results would require a large randomized trial.

Application to Clinical Practice  These results suggest PRP costs to some patients in terms of travel and lost productivity as well as to eye care providers could be reduced.

Trial Registration Identifier: NCT00687154.