Abstract
Purpose: :
To determine the relative sensitivity of multiple parameters measured by spectral domain optical coherence tomography (SD-OCT) in patients with macular edema from branch or central retinal vein occlusion (BRVO/CRVO) after intravitreal bevacizumab injection.
Methods: :
Retrospective review of 18 eyes of 18 patients (age = 66.6 ± 13.0 years) from the retina practice of a tertiary care center with macular edema associated with BRVO or CRVO undergoing SD-OCT imaging prior to and within 3-6 weeks of the injection. The study eyes were also compared with 18 normal control eyes of 18 patients (mean age = 70 ± 9.3). The primary outcome measure was the change in macular volume, average and 9 macular subfield thickness measurements, as measured by Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA), as well as pre- and post-injection visual acuity (VA).
Results: :
Visual acuity following injection improved significantly (0.83 ± 0.44 to 0.55 ± 0.26 logMAR Snellen VA, p=0.004). Change in macular volume was not statistically significant, with a mean pre-injection volume of 11.5 ± 2.0 mm3, as compared with post-injection volume of 11.0 ± 1.1 mm3 (p=0.29, paired t-test). Change in mean central macular thickness was significant (510 ± 195 to 346 ± 92 microns, p=0.004), as were all superior and temporal macular subfields (central superior: 399 ± 134 to 337 ± 93, p=0.05; peripheral superior: 302 ± 75 to 282 ± 66, p=0.016; central temporal: 407 ± 99 to 351 ± 65, p=0.03; peripheral temporal: 321 ± 62 to 290 ± 32, p=0.01). The change in mean inferior and nasal subfields and in average thickness was not statistically significant. Macular volume, average, and all 9 macular subfield thickness measurements both before and after injection were significantly higher than control eyes without macular edema.
Conclusions: :
Mean central macular thickness is a more sensitive parameter than macular volume in response to intravitreal bevcizumab injection for patients with BRVO or CRVO. The study also supports the emerging use of SD-OCT as a powerful clinical tool for quantifying and comparing parameters of retinal volume and thickness in various disease states of the retina.
Keywords: imaging/image analysis: clinical • retina • edema