Evaluation of the Foveal Avascular Zone in Familial Exudative Vitreoretinopathy Using Optical Coherence Tomography Angiography

Background: To evaluate the foveal avascular zone (FAZ) and retinal structure in familial exudative vitreoretinopathy (FEVR). Methods: : Twenty FEVR eyes with stage 1 or 2 disease and 20 control eyes were evaluated. The central retinal thickness (CRT), inner retinal thickness (IRT), surface retinal vessel density (SRVD), and deep retinal vessel density (DRVD) were measured using optical coherence tomography. The FAZ area was calculated using ImageJ software. The equivalent spherical value (SE) and axial length (AL) were measured. Results: : The CRT (232±26.75 vs. 213.15 ± 16.138 μm; p =0.0003) and IRT (17.44±13.28 vs. 1.85 ± 5.696 μm; p =0.0005) were thicker in the FEVR group than in the control group. The surface FAZ area (0.26±0.1 vs. 0.33 ± 0.1 mm 2 ; p =0.006) and the deep FAZ area (0.36±0.1 vs. 0.43 ± 0.1 mm 2 ; p =0.037) were smaller in the FEVR group than in the control group. The SRVD values did not differ among the sectors, but the DRVD was higher in the FEVR group except for the inferior sector (superior, p =0.02; inferior, p=0.4; temporal, p =0.001; nasal, p =0.02). The SE and AL did not differ between the two groups. There was no correlation between the surface and deep layer FAZ area and age, CRT, SE, and AL. The surface, deep FAZ area, and IRT were correlated negatively (surface, r = −0.57, p =0.008; deep layer FAZ area, r = −0.5, p =0.02). Conclusion: Eyes with FEVR has a smaller FAZ because the inner retina with the vascular structure remained in the fovea.