Posters

Comparison of foveal avascular zone size and diameter in retinal ischemia measured using two different optical coherence tomography angiography devices

Poster Details

First Author: A.Tasiopoulou UK

Co Author(s):    D. Grewal   B. Pal                 

Abstract Details

Purpose:

To compare the quantitative differences in assessment of the foveal avascular zone area in patients with retinal ischemia of various etiologies using two Spectral Domain Optical Coherence Tomography Angiography (OCTA) Platforms.

Setting:

Moorfields Eye Hospital, London, UK

Methods:

12 eyes (9 patients) with retinal ischemia of different etiologies (4Diabetic macular edema, 1Central retinal vein occlusion, 3Behcets Disease, 3Ischemic retinal vasculitis, 1Sickle cell retinopathy) were scanned simultaneously using Angiovue and Zeiss AngioPlex. 3x3mm slabs of superficial and deep retinal capillary plexus were generated and manual segmentation performed for the anatomical boundaries. Images were then exported to ImageJ. The area of the foveal avascular zone (mm2) and the greatest linear diameter horizontal and vertical (GLDH and GLDV, mm) of both superficial and deep plexus were measured on both platforms by two independent retinal experts. Intergrading reliability was evaluated.

Results:

Intergrader agreement between two observers was good.Using the Optovue and Zeiss Angioplex mean superficial (0.642 �Â�± 0.43 vs. 0.72 �Â�± 0.32 mm 2, p=0.32) and deep (1.262 �Â�± 0.04 vs. 1.218 �Â�± 0.65 mm2, p=0.4) FAZ areas were similar. Superficial GLDH (1.347 �Â�± 0.70 vs.1.689 �Â�± 0.35 mm, p=0.11) and GLDV (1.386 �Â�± 0.614 vs.1.587 �Â�± 0.31 mm, p=0.18) and deep GLDH (2.032 �Â�± 0.72 vs. 1.851 �Â�± 0.578 mm, p=0.26) and GLDV (2.0661 �Â�± 0.917 vs. 1.849 vs. 1.135 mm, p=0.27) were also similar. There was significant agreement using the two platforms (r=0.69, p=0.03 and r=0.71, p=0.02 respectively).

Conclusions:

There are minor differences in the measurement of superficial and deep FAZ area and horizontal and vertical GLD in retinal ischemia of different etiologies using the two different OCT angiography platforms. While these differences were not statistically significant in this limited series, care should be taken when assessing patients with retinal ischemia using different platforms as FAZ measurements may not be interchangeable.

Financial Disclosure:

travel has been funded, fully or partially, by a competing company