Purpose
-To report outcomes of focal laser photocoagulation for clinically significant macular edema (CSME) among diabetics at the LAC+USC eye clinic, a predominantly underinsured, Hispanic patient population -To identify clinical predictors of favorable outcome
Methods
IRB approval was obtained. Retrospective chart review was performed on patients who received focal/grid laser photocoagulation for CSME, as defined by the ETDRS, from Sept 1, 2010 to March 31, 2011 at the LAC+USC Eye Clinic. The primary outcome measures were: (1) improvement in visual acuity by 1 line or more (similar to measured reported in ETDRS Report 1), and (2) reduction in OCT central subfield foveal thickness by 50 microns or more at 2-4 months.Baseline and follow-up parameters were collected from sociodemographic and clinical chart data, lab results, and OCT data.
Results
Of 177 eyes that received laser over the 6-month study period: 72 were excluded because of poor quality OCT or lack of follow-up, and 105 had complete follow-up data at 2-4 months. 70% of the LA County study population (with baseline visual acuity worse than 20/40 and mild to moderate diabetic retinopathy) experienced improved visual acuity by 1 line or better at 2-4 months after receiving focal laser. This is compared to 40% of the ETDRS population, with the same baseline parameters, who experienced at least 1 line of improvement in vision at 1 year. Like the ETDRS, there was no significant difference in the mean log MAR visual acuity before and after laser (0.56 post-focal, as compared to 0.57 pre-focal; p=0.8). The mean foveal central subfield thickness (CST) improved from 356 microns to 329 microns after laser (p=0.006), and 40% experienced reduction of CST by 50 microns or more. Of all the sociodemographic and clinical variables collected, the only univariate predictor of visual acuity improvement by 1 line or more was having total cholesterol of less than 200 (odds ratio 5.69 [1.50-21.4]; p=0.01). In contrast, subfoveal hard exudates (OR 7.41 [1.19-46.2]; p=0.03) predicted visual acuity outcome worse than 20/40.
Conclusions
Our patient population had a favorable response to focal laser treatment, compared to historical white populations, at least at shorter follow-up. Focal laser remains an efficacious treatment option for DME, especially in patients with limited follow-up capabilities and in lower resource settings.
Keywords: 462 clinical (human) or epidemiologic studies: outcomes/complications •
505 edema •
499 diabetic retinopathy