Abstract
Purpose :
To investigate the impact of vitreomacular adhesion (VMA) on the number of antiVEGF injections required to manage eyes with diabetic macular edema (DME). Secondly, to evaluate the induction rate of a posterior vitreous detachment (PVD) after Ranibizumab injections, compared to natural course.
Methods :
Patients with diffuse DME were enrolled in this prospective observational study. Previous vitrectomy or significant vitreomacular traction were exclusion criteria. Patients were evaluated every 2 months during one year, with best-corrected acuity (BCVA) and spectral-domain optical coherence tomography examination (Cirrus 4000, Zeiss) to assess central foveal thickness (CFT) and PVD stage. Patients were divided into stage 0 (posterior hyaloid attached to the fovea or VMA) and stage 1 (foveal detachment of the posterior hyaloid). All patients received a loading dose of three Ranibizumab injections (0.5mg) and were retreated every 2 months if VA was 20/30 or lower and/or CFT was greater than 300µm.
Results :
Thirty-eight eyes of 28 patients with DME were included in the study group and ten eyes of 10 diabetic matched patients without DME were included in the control group. Baseline characteristics of both groups with DME (VMA and PVD groups) were similar, in terms of age, gender, glycemic control, BCVA and CFT. VMA was present in 23.7% of the patients at baseline and in 52.6% of the patients at the end of the study. Mean time for the appearance of a posterior PVD was 7.4 months, and by month 6 vitreous was still attached to the fovea in 60.5% of the patients. Patients with VMA required 4.8±1.7 injections while patients with detached vitreous, at baseline or anytime during the study period, required 5.4±1.7 injections to treat the DME. This difference did not reach statistical significance (p=0.332).
Conclusions :
Ranibizumab injections induced a PVD in 30% of patients with VMA, whereas it did not spontaneously occur in any of the control subjects during the 12 months period. Moreover, patients with attached vitreous to the fovea showed a tendency to require fewer injections than patients with a PVD, with comparable visual gain and CFT reduction. In DME management, it is crucial to differentiate vitreomacular traction from eyes with VMA, as these latter may respond better to antiVEGF injections than eyes with a detached vitreous.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.