Changes in retinal nonperfusion observed on ultra-widefield angiography in patients with retinal vein occlusion treated with ranibizumab

Abstract

 

Purpose

 

To evaluate the changes in retinal non-perfusion (RNP) observed on ultra-widefield angiography in patients with branch or central retinal vein occlusion (BRVO or CRVO) treated with ranibuzumab.

 

Methods

 

Patients with retinal vein occlusion received six monthly intraocular injections of ranibuzumab. At Baseline and Month 6, patients underwent ultra-widefield fluorescein angiography (UWFA) and fundus photography using the Optos 200Tx Ultra-Widefield retinal imaging device (Optos PLC, Dunfermline, UK). Patients who demonstrated retinal non-perfusion at baseline visit were enrolled. A single best quality image from each angiogram series during the arteriovenous phase was selected at both visits. The selected images were transformed using the Optos image projection software (Natasha M et al., ARVO 2013) to remove warping of geometrical dimensions. Month 6 images were co-registered to the baselines. The Baseline-Month 6 paired images with cross-correlation of within ±0.3 were selected for further grading. Two trained graders, masked to visit and diagnosis, manually annotated RNP within the modified 7-fields (7M-D) and within the maximum common visible area at both visit using ImageJ (Version 1.47v, NIH). Areas of hemorrhage at baseline were not graded at both visits. Intra-class correlation coefficient (ICC) was calculated and the average value of the two graders was used for further analysis. Primary outcome measures included change in RNP area within 7M-D field and periphery at month 6 (Figure 1).

 

Results

 

Sixteen images of eight eyes with retinal vein occlusion (5 BRVO, 3 CRVO) were evaluated. The ICC between two graders was 0.90 (95% CI: 0.86 -0.93). The average total visible area of retina (TR) was 589.7 mm² (SD ± 69.0). Mean area of RNP at baseline was 3.6mm² within the 7 M-D fields and 46.9mm² in the peripheral region; the latter is not viewed on the conventional 7M-D fluorescein angiogram. Mean area of RNP significantly decreased at Month 6 ( Δ_Total= 14.2 mm² , p=0.002; Δ_{Within 7M-D fields} = 1.9 mm² , p = 0.07; Δ_{Peripheral region} = 12.3 mm ² , p<0.0001) (Table 1).

 

Conclusions

 

Nonperfusion area in eyes with venous occlusive disease decreased at month 6, with more reperfusion noted in the peripheral region compared to within 7M-D fields. UWFA may be valuable in quantitatively evaluating retinal non-perfusion changes especially in the peripheral region.

 

 

 

Keywords: 688 retina • 572 ischemia • 550 imaging/image analysis: clinical