Abstract
Purpose: :
Diabetic macular edema (DME) is the major cause of vision loss in patients with diabetic retinopathy. Focal macular edema (ME) is treatable by microaneurysm-targeted laser photocoagulation, while diffuse ME is often refractory to grid laser photocoagulation performed without concrete targets. Our previous study showed that microaneurysms were more detectable by indocyanine green angiography (IA) than fluorescein angiography (FA) (BJO 2010;94:600). The purpose of this study is to evaluate the usefulness of IA-guided assessment and laser photocoagulation for DME.
Methods: :
Thirteen eyes with DME were enrolled. Mean age was 71.6 years. The mean follow-up was 16.1 months (range 3 to 36). FA and IA were performed with Heidelberg Retina Angiogram 2. ME was diagnosed as ‘focal’ when responsible microaneurysms or leaking spots were detectable, otherwise as ‘diffuse’. On the basis of images on FA or IA, ME was classified into 3 groups: focal ME, mixed ME, or diffuse ME. Middle or late phase IA-guided laser photocoagulation was performed. Subtenon’s injection of triamcinolone acetonide (STTA) (20 mg) was additionally performed as needed. The central macular thickness (CRT) and macular volume (MV) were measured periodically by optical coherence tomography. The best-collected visual acuity (BCVA) was measured.
Results: :
Based on FA, 2 eyes (15.4%) were classified as focal ME, 4 eyes (30.8%) mixed ME, and 7 eyes (53.8%) diffuse ME. In contrast, IA detected 12 eyes (92.2%) as focal ME and 1 eye (7.8%) as mixed ME with significant sensitivity (p<0.0001, Fisher’s exact test). Mean BCVA was changed from 0.68±0.33 at the baseline to 0.58±0.37 (p<0.05) at the best and 0.60±0.36 at the last visit in the logarithm of minimum angle of resolution unit. CRT and MV were significantly decreased from 375±121 μm and 12.7±1.3 mm3 to 300±90μm (p<0.05) and 10.8±1.2 mm3 (p<0.001), respectively.
Conclusions: :
IA was more sensitive to detect responsible microaneurysms for DME than FA. On IA, microaneurysms or focal leaking spots were detectable even in ME considered as a diffuse type on the basis on FA. IA-guided laser photocoagulation might be effective for the treatment of ME.
Keywords: edema • laser • diabetic retinopathy