Analysis of Macular Edema after Cataract Surgery in Patients with Diabetes Using Optical Coherence Tomography
Received 5 December 2005; accepted 23 August 2006. published online 01 February 2007.
Objective
To assess the incidence or progression of macular edema (ME) after cataract surgery in diabetic patients using optical coherence tomography (OCT) and correlating this with degree of diabetic retinopathy or other risk factors.
Design
Prospective cohort study.
Participants
Fifty diabetic eyes undergoing cataract surgery.
Methods
Each eye underwent 7-field fundus photography no more than 3 months before surgery. Optical coherence tomography testing was performed within 4 weeks before surgery and at 1- and 3-month postoperative visits. Best-corrected visual acuity (BCVA) was recorded at each visit. Macular edema was defined as an increase of center point thickness on OCT > 30% from preoperative baseline.
Main Outcome Measures
Changes in foveal thickness and BCVA.
Results
The incidence of ME on OCT was 22% (95% confidence interval, 13%–35%). The average increase in center point thickness at 1 month for eyes with ME was 202 μm, which resulted in a nearly 1-line loss of vision (0.07 logarithm of the minimum angle of resolution [logMAR] units) compared with eyes without ME gaining >2 lines of vision (0.24 logMAR units) (P>0.001). Eyes with no diabetic retinopathy developed minimal thickening of 18 μm and 14 μm at 1 and 3 months, respectively, associated with approximately 2 and 3 lines of improved vision, respectively (0.22 and 0.26 logMAR units). Eyes with moderate or severe nonproliferative diabetic retinopathy or proliferative diabetic retinopathy developed thickening of 145 μm and 131 μm at 1 and 3 months, respectively, associated with <1 and 2 lines of improved visual acuity, respectively (0.08 and 0.17 logMAR units). This difference (P = 0.05) in thickening (127 μm and 117 μm at 1 and 3 months, respectively) was correlated inversely with visual improvement (r = −0.662). Both duration of diabetes ≥ 10 years (P = 0.04) and insulin dependence (P = 0.007) were associated with reduced visual improvement.
Conclusions
Diabetic eyes have a high incidence of increased center point thickness on OCT after cataract surgery, associated with a loss of vision at 1 month, with limited visual recovery at 3 months. Treatment to prevent this might improve outcomes in similar individuals after surgery.
Retina Division, Wilmer Eye Institute (Department of Ophthalmology), Johns Hopkins University School of Medicine, Baltimore, Maryland.
Manuscript no. 2005-1187.
Supported by the James P. Gills Professorship (NMB) and Wilmer Retina Division Research Fund.
Dr Bressler’s employer, Johns Hopkins University, but not Dr Bressler, receives funding for research and educational services provided by the Johns Hopkins University School of Medicine Department of Ophthalmology through efforts of Dr Bressler from Carl Zeiss Meditec, the manufacturer of the optical coherence tomograph used in this research project.
ABSTRACT