Factors affecting visual outcomes in patients with diabetic macular edema treated with ranibizumab

Abstract

Purpose: To identify factors associated with visual outcomes in patients with diabetic macular edema (DME) treated with ranibizumab (RBZ) in the Ranibizumab for Edema of the mAcula in Diabetes-Protocol 2 (READ-2) Study.

Patients and methods: Optical coherence tomography scans, fundus photographs, and fluorescein angiograms (FAs) were graded and along with baseline characteristics were correlated with month (M) 24 visual outcome of best-corrected visual acuity (BCVA) ≤20/100 (poor outcome) vs >20/100 (better outcome).

Results: Of 101 patients with a M20 visit or beyond, 27 (27%) had BCVA ≤20/100. Comparison of patients with or without poor outcome showed mean baseline BCVA of 16.8 letters (20/125) in the former compared with 30.4 letters (20/63; P<0.001). Mean change in BCVA between baseline and M24 was -2.6 letters in the poor outcome group compared with +9.8 letters (P<0.001). Foveal thickness (FTH) at M24 was 374.1 μm in the poor outcome group compared with 268.8 μm (P<0.01), a difference driven by 14 patients with mean FTH of 450.3 μm. Foveal atrophy occurred in 65% (11/17) in the poor outcome group compared with 17%(12/71, P=0.001). Persistent edema was noted in 52% (14/27) of patients with poor outcome. Laser scars near foveal center were significantly more common in patients with poor outcome who did not have edema vs those who did (78% (7/9) vs 23% (3/13) P=0.03).

Conclusion: Poor baseline BCVA (≤20/125) in DME patients predicts poor visual outcome (≤20/100) after 2 years of treatment with RBZ and/or focal/grid laser, often due to foveal atrophy and/or persistent edema.

Figure 1

Images at M24 of a patient with poor visual outcome in which recurrent macular edema contributed. Fundus photograph (a) and red-free photograph (b) show some pigmentary changes adjacent to the fovea, laser burns temporally, exudates inferiorly, and a few hemorrhages and microaneurysms. An early frame of a FA taken 43 s after dye injection (c) shows many microaneurysms and areas of capillary closure temporally and superiorly. A late frame of the FA taken 11 min and 3 s after dye injection (d) shows severe leakage with pooling of dye in the fovea in a petaloid pattern. A horizontal time domain OCT scan through the fovea (e) shows severe thickening and intraretinal fluid.

Figure 2

Images at M24 of a patient with poor visual outcome in which recurrent macular edema did not contribute. Fundus photograph (a) and red-free photograph (b) show some numerous laser scars surrounding the fovea (within 1 mm) and throughout the posterior pole. An early frame of a fluorescein angiogram (FA) taken 41 s after dye injection (c) shows hyper- and hypofluorescent spots in areas of laser burns and pigmentary changes and some microaneurysms between the disc and fovea. A late frame of the FA taken 10 min and 48 s after dye injection (d) shows mild leakage associated with the microaneursyms near the disc, but no leakage or pooling of dye near the fovea. A horizontal time domain optical coherence tomography scan through the fovea (e) shows no thickening or intraretinal fluid.