Abstract
Purpose:
Diabetic macular edema (DME) is the major cause of vision loss in patients with diabetic retinopathy. Focal DME is treatable by microaneurysm-targeted laser photocoagulation (PHC), while diffuse DME is often refractory to grid laser photocoagulation performed without concrete targets. Previously, we reported that indocyanine green angiography (IA) could detect responsible leaking points even for diffuse DME more sensitively than fluorescein angiography (FA) and that IA-guided PHC was effective for the treatment of DME (ARVO 2012). The purpose of this study is to evaluate long-term efficacy of IA-guided PHC for DME.
Methods:
Eighteen eyes of 12 patients with diffuse DME diagnosed conventionally on FA were enrolled. Mean age was 68.0 years. The mean follow-up period was 18.4 months (range 12 to 24). FA and IA were performed with Heidelberg Retina Angiogram 2. IA-guided PHC was performed on the basis of middle or late phase IA. Subtenon’s injection of triamcinolone acetonide (STTA) (20mg) was additionally performed as needed. The best-collected visual acuity (BCVA) was measured. The central retinal thickness (CRT) and macular volume (MV) were measured periodically by optical coherence tomography.
Results:
Mean BCVA in the LogMAR unit was significantly improved from 0.56±0.10 at baseline to 0.47±0.08 in month 6 (p<0.05) and 0.46±0.08 in month 12 (p<0.05). The mean CRT was significantly decreased from 420±26.5 μm to 265±16.8 μm (p<0.01) and 258±15.3 μm (p<0.01), respectively. Mean MV was also significantly decreased from 13.4±0.34 mm3 to 11.4±0.26 mm3 (p<0.01) and 11.3±0.28 mm3 (p<0.01), respectively. In month 12, the BCVA was improved by 0.3 or more LogMAR units in 3 eyes (17%), stable in 14 eyes (78%), and worsened only in 1 eye (6%). STTA was performed in 8 eyes (44%), one of which has undergone retreatment of STTA. Additional PHC was performed only in 1 eye.
Conclusions:
IA is useful to detect targets of PHC even for diffuse DME. IA-guided PHC may be effective with lower recurrence rate for the treatment of diffuse DME. Further study is needed to compare other treatment modalities such as anti-vascular endothelial growth factor therapy.
Keywords: 499 diabetic retinopathy •
505 edema •
578 laser