Correlation of novel macular structural and vascular abnormalities in familial exudative vitreoretinopathy

Abstract

Purpose : To correlate retinal structural and microvascular abnormalities in familial exudative vitreoretinopathy (FEVR).

Methods : Twenty-two eyes (11 eyes of 6 FEVR patients, 11 eyes of 11 normal controls) were prospectively imaged using an investigational Spectralis spectral-domain optical coherence tomography angiography (OCTA) device. Fovea-centered scans (10° x 10°) were obtained, and images of the superficial (SVC) and deep vascular complexes (DVC) were previously graded for the presence of vascular end-bulbs.¹Total retinal thickness was measured in 9 macular sectors. Fluorescein angiography (FA) was performed the same day and graded for the presence of macular vessel straightening or dragging.¹Findings across multimodal imaging were correlated.

Results : Average total retinal thickness in FEVR eyes was similar to controls (mean ± SD: 341 ± 52µM and 325 ± 33µM respectively). Retinal thickness appeared to increase by stage of FEVR: 2a (331 ± 26µM), 2b (325 ± 34µM), 3b (396 ± 52µM), 5 (288 ± 39µM)—the one stage 5 eye had been previously vitrectomized. When evaluating regional retinal thicknesses, the superior macula was least affected. FEVR eyes with thicker retinas qualitatively had thickened posterior hyaloid (TPH), which occurred more frequently in higher stages of disease (2a: 0/2, 2b: 1/5, 3b: 2/3). TPH was not seen in controls. TPH was seen in 3 out of 4 eyes with vessel straightening on FA. The 3 eyes with TPH also had end-bulbs on OCTA. Four eyes with end-bulbs on OCTA but no TPH had similar retinal thickness compared to controls. End-bulbs on OCT-A could be seen on OCT as hyper-reflective foci in the inner nuclear layer (Figure).

Conclusions : Retinal thickening in eyes with FEVR is associated with thickened posterior hyaloid on OCT, more severe disease stage, vascular dragging on FA, and end-bulbs on OCTA. Visualization of end-bulbs on OCTA and their associated hyper-reflective foci in the inner nuclear layer on OCT may be explored as imaging-based biomarkers of FEVR.

¹Hsu ST, et al. AAO 2018. PO230

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

OCTA and OCT from FEVR (A, B) and control (C,D). The deep vascular complex (DVC) of FEVR (A) has end-bulbs, which correspond to hyper-reflective foci on OCT (B). A vessel in the DVC from a similar eccentricity in a normal control (C) does not show hyperreflectivity (D). Comparison of the OCT of FEVR (B) to control (D) also shows a thickened posterior hyaloid and increased retinal thickness.