Peripheral Retinal Perfusion and Functional Analysis of Patients with Ischemic Central Retinal Vein Occlusion

Abstract

 

Purpose

 

Progressive retinal perfusion and peripheral visual field (VF) changes in eyes with central retinal vein occlusions (CRVO) are incompletely understood. Our purpose was to quantify long-term trends in capillary non-perfusion and VF patterns in patients with ischemic CRVO treated with ranibizumab over 36 months.

 

Methods

 

Wide-field fluorescein angiography (FA) and Goldmann VF (GVF) were performed serially in patients with ischemic CRVO who were treated in the 36-month prospective Rubeosis Anti-VEGF (RAVE) trial evaluating intravitreal ranibizumab. All patients received ranibizumab injections for 9 months followed by pro re nata ranibizumab in months 12-36. Serial wide-field FA was performed with a Heidelberg Spectralis HRA utilizing the Staurenghi contact lens. Areas of perfusion/non-perfusion were graded by masked graders and pixels quantified. GVF were assessed every 6 months and changes in the I-4e isopter were analyzed.

 

Results

 

Twelve patients had sequential wide-field FA for 36 months. At baseline, mean perfusion was 36.7% (106.4 disc areas) of the gradable field (mean: 290 disc areas, range 178-452). The area of non-perfusion increased in all patients with a mean loss of approximately 5% of retina area (loss of 14.5 mean disc areas of perfusion) per 6 month period. In comparison to progressive loss of perfusion, 3 patterns of GVF progression were identified: early loss (n=6), early gain with late loss (n=3), and stability (n=3). Progressive non-perfusion and changes in GVF were most pronounced in the first year of the trial. Despite capillary and GVF losses, vision improved in these eyes from a baseline of 23.1 best corrected Early Treatment Diabetic Retinopathy Study (ETDRS) letters to 30.5 ETDRS letters (mean gain: +7.4 letters) at month 36.

 

Conclusions

 

In this prospective CRVO trial, progressive capillary loss was quantified. Similarly, peripheral visual field loss as measured by GVF progressed in most eyes (n=9). Changes in perfusion and GVF were particularly evident in the first year of treatment. Despite perfusion and GVF losses in many patients, vision improved, as the majority of these anatomic and functional changes were peripheral.

 

 

Wide field fluorescein angiogram of ischemic CRVO at baseline

 

 

Wide field fluorescein angiogram of the same ischemic CRVO after 2 years of intravitreal ranibizumab treatment showing extensive loss of retinal perfusion

 

Keywords: 572 ischemia • 749 vascular occlusion/vascular occlusive disease • 550 imaging/image analysis: clinical