Abstract
Purpose:
To identify baseline anatomic characteristics on spectral-domain optical coherence tomography (SD-OCT) in treatment-naïve patients with diabetic macular edema (DME) that may help predict better response to intravitreal anti-vascular endothelial growth factor (VEGF) therapy.
Methods:
Retrospective, observational case series of treatment-naïve patients (no prior injections or laser) diagnosed with DME who were subsequently treated with ranibizumab or bevacizumab at the Retina Service of Wills Eye Hospital (Philadelphia, PA). Pertinent clinical data, including age, gender, baseline and follow-up visual acuity (VA), biomicroscopic examination findings, injection history, and length of follow-up were all recorded. Serial SD-OCT scans were analyzed for internal structure and measurements were obtained for subfoveal choroidal thickness (SFCT), foveal thickness (FT), and central macular thickness (CMT). Statistical analysis was performed using a paired two-tailed t-test.
Results:
Nineteen eyes with DME met inclusion criteria. Initial measurements were compared to those after 3 monthly injections of ranibizumab/bevacizumab. In eyes with initial SFCT > 250 µm (n=10), subsequent SFCT reduction observed was statistically significant (p=0.002), but not in eyes with initial SFCT < 250 µm (n=9, p=0.06). Mean change in logMAR VA showed a positive trend towards improvement in both groups with greatest change in eyes with thicker initial SFCT (< 250 µm: mean change -0.07, p=0.12; > 250 µm: mean change -0.10, p=0.08). In eyes with initial SFCT < 250 µm, the average FT decreased by 22% from 363.6 to 283.6 µm (p=0.01), whereas CMT decreased by 19.7 % from 434.3 to 348.7 µm (p=0.02). In eyes with initial SFCT > 250µm, the average FT decreased by 13.8% from 367.3 to 316.7 µm (p=0.06) and average CMT decreased by 12.9% from 468.8 to 408.2 µm (p=0.03).
Conclusions:
Quantifiable SD-OCT anatomic characteristics, such as SFCT, appear to show promise in identifying eyes with DME that may respond more favorably to intravitreal anti-VEGF pharmacotherapy. In this study, eyes with thinner baseline SFCT had greater reductions in FT and CMT after intravitreal anti-VEGF injections.
Keywords: 499 diabetic retinopathy •
452 choroid •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)