Abstract
Purpose :
To determine whether the presence of a posterior vitreous detachment (PVD) modifies the clinical course of diabetic macular edema (DME) in eyes treated with intravitreal Ranibizumab.
Methods :
Patients with diffuse or multifocal DME were enrolled in this prospective, observational cohort study. Exclusion criteria included previous vitrectomy, significant vitreomacular traction and DME treatment in the last 4 months. Participant evaluation was every 2 months during 12 months, and included visual acuity (VA), using decimal Snellen notation, and spectral-domain optical coherence tomography examination to assess central foveal thickness (CFT) and PVD stage. Patients were divided into stage 0 (posterior hyaloid attached to the fovea) and stage 1 (foveal detachment of the posterior hyaloid). All patients received a loading dose of three Ranibizumab injections and were retreated with another injection 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. Patients were classified in two groups according to PVD stage at month 12 (Stage 0: n=18 / Stage 1: n=20). At month 12, patients with vitreomacular adhesion (VMA) showed a significant visual improvement, from 0.26±0.16 to 0.36±0.22 (p=0.025) and a significant decrease in CFT, from 570±194µm to 311±146µm (p=0.001). Patients with foveal vitreous detachment (Stage 1) experienced a significant reduction in CFT, from 485±106µm to 367±175µm (p=0.002) but not a statistically significant visual improvement (p=0.084). Patients with attached posterior hyaloid showed a higher improvement in VA and CFT reduction compared with patients with foveal vitreous detachment, although this difference did not reach statistical significance.
Conclusions :
The role of vitreomacular interface in the therapeutic response in patients with diabetic retinopathy, specially with DME without a clear tractional component, is discussed. Our data indicate that patients with VMA show a tendency to be more responsive to DME treatment with Ranibizumab injections. It is unclear whether this differences could be explained solely by a mechanical action of the posterior hyaloid over the macula or by changes in VEGF and other cytokines in the posterior vitreous.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.