Abstract
Purpose: :
To estimate the incidence of center-involved macular edema (ME) at 16 weeks following cataract surgery in eyes with diabetic retinopathy and no definite center involved diabetic macular edema pre-operatively. Secondary analyses included visual acuity (VA) and assessment of baseline risk factors.
Methods: :
Multi-center, prospective, observational study of eyes with OCT central subfield (CSF) thickness<250 um time domain (TD) or <310 um SD who had diabetic retinopathy and underwent cataract surgery < 28 days after enrollment. The primary outcome was worsening to central-involved ME at 16 weeks, defined as CSF thickness of >250 um TD or > 310 um SD with > 1-step increase in the logOCT thickness compared to baseline, or > 2-step increase in the logOCT CSF thickness from baseline or receiving treatment (other than eye drops) for ME prior to 16 weeks on the basis of the above criteria. Protocol refraction, best corrected E-ETDRS VA, fundus exam, and OCT were performed at all study visits.
Results: :
Two hundred seventy six eyes were eligible for analysis (median age 65yrs, median VA letter score 70 [approximate Snellen equivalent 20/40], and 42% had a history of treatment for DME). At 16 weeks post-op, preliminary results show 30 eyes (11%) worsened to central-involved ME (95% CI 7-15%). Twenty-three eyes (8%) received post-op ME treatment other than eye drops; of these, 7 did not worsen to central-involved ME. At 16 weeks, 216 eyes (78%) achieved 20/40 or better VA. Of the 30 eyes that developed central-involved ME, 14 eyes (47%) achieved 20/40 or better VA. Among baseline factors evaluated, history of DME treatment (P<0.001), showed possible association with the primary outcome.
Conclusions: :
Sixteen weeks after cataract surgery for eyes with diabetic retinopathy but no definite center-involved edema, 7% to 15% will worsen to central-involved edema. To our knowledge, it is unknown at this time how many similarly followed eyes without diabetes or diabetic retinopathy will worsen to center-involved edema. Going forward, research may clarify which individuals with diabetes are at highest risk for central-involved ME and whether treatments might mitigate vision loss associated with development of central-involved ME after cataract surgery.
Keywords: diabetic retinopathy