Subretinal fibrosis in diabetic macular edema. ETDRS report 23. Early Treatment Diabetic Retinopathy Study Research Group
D. S. Fong, P. P. Segal, F. Myers, F. L. Ferris, L. D. Hubbard and M. D. Davis
King/Drew Medical Center, Jules Stein Eye Institute, UCLA, USA. dsfong@ucla.edu
OBJECTIVE: To describe the characteristics of and risk factors for
subretinal fibrosis (SRF) in patients with diabetic macular edema. PATIENTS
AND METHODS: A total of 109 eyes (in 96 persons) with SRF, defined as a
mound or sheet of gray to white tissue beneath the retina at or near the
center of the macula, were identified during the Early Treatment Diabetic
Retinopathy Study, which is a randomized clinical trial of photocoagulation
and aspirin treatment in patients with mild to severe nonproliferative or
early proliferative diabetic retinopathy. The patients and the ocular
characteristics of these 109 eyes, all of which had clinically significant
macular edema, were compared with those of 5653 eyes in which clinically
significant macular edema, but not SRF, was observed during the trial.
RESULTS: In 9 of 109 eyes, the development of SRF may have been directly
related to focal photocoagulation. Seventy-four percent of the eyes in
which SRF developed had very severe hard exudates in the macula prior to
the development of SRF, while this level of hard exudates was seen in only
2.5% of the eyes with clinically significant macular edema in which SRF did
not develop (P < .001). Of the 264 eyes with this level of hard exudates
at baseline (n = 29) or during follow-up (n = 235), SRF developed in 30.7%
of the eyes, while this complication developed in only 0.05% of 5498 eyes
with clinically significant macular edema without this level of hard
exudates. CONCLUSIONS: Subretinal fibrosis is an infrequent complication of
diabetic macular edema. Although it has been reported to be associated with
photocoagulation burn intensity, in only 9 of 109 eyes in which SRF
developed was it located adjacent to a photocoagulation-related scar (among
4823 eyes that received focal photocoagulation for treatment of macular
edema). The strongest risk factor for the development of SRF is very severe
hard exudate.
