The course of response to focal/grid photocoagulation for diabetic macular edema.
OBJECTIVE
The purpose of this study was to determine whether eyes with center-involved diabetic macular edema, treated with focal/grid photocoagulation, in which there is a reduction in central subfield thickness (CST) measured with optical coherence tomography after 16 weeks, will continue to improve if retreatment is deferred.


METHODS
This is a prospective, multicenter, observational, single-group focal/grid photocoagulation study of 122 eyes with center-involved diabetic macular edema (optical coherence tomography CST > or =250 microm). At the 16-week visit and continuing every 8 weeks, eyes were assessed for retreatment and additional laser treatment was deferred if the visual acuity letter score improved > or =5 letters or optical coherence tomography CST decreased > or =10% compared with the visit 16 weeks prior.


RESULTS
Of the 115 eyes that completed the 16-week visit, 54 (47%) had a decrease in CST by > or =10% compared with baseline. Of these, 26 (48%) had a CST > or =250 microm at 16 weeks and were evaluable at 32 weeks. Eleven (42%; 95% confidence interval, 23-63%) of the 26 eyes had a further decrease in CST > or =10% from 16 weeks to 32 weeks without further treatment.


CONCLUSIONS
Sixteen weeks after focal/grid laser for diabetic macular edema in eyes with a definite reduction, but not resolution, of central edema, 23% to 63% likely will continue to improve without additional treatment.
D000368:Aged; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D017075:Laser Coagulation / Q000379:methods*; D008269:Macular Edema / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019233:Retreatment; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology