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

Abstract

Purpose

To evaluate the foveal avascular zone (FAZ) and retinal structure in familial exudative vitreoretinopathy (FEVR).

Patients and Methods

Eighteen eyes with stage 1 or 2 FEVR and 20 control eyes were evaluated. The central retinal thickness (CRT), foveal 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 (232.5±3.086 vs 211±12.6325 μm; p=0.003) and foveal IRT (15.83±13.95 vs 0.9±4.02 μm; p=0.002) were thicker in the FEVR group than in the control group. The surface FAZ area (0.265±0.08 vs 0.364±0.09 mm²; p=0.004) and the deep FAZ area (0.364±0.1 vs 0.484±0.11 mm²; p=0.03) 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=0.027; inferior, p=0.88; temporal, p=0.035; nasal, p=0.027). The SE and AL did not differ between the two groups. There were no correlations between the surface and deep layer FAZ area and age, CRT, SE, and AL. The surface, deep FAZ area, and foveal IRT were correlated negatively (surface, r = −0.47, p=0.033; deep layer FAZ area, r = −0.46, p=0.037).

Conclusion

Eyes with FEVR have a smaller FAZ because the vascular structure in the inner retina remained in the fovea.

Keywords:

• familial exudative vitreoretinopathy
• optical coherence tomography angiography
• foveal avascular zone

Ethics

The Institutional Review Board of the Saitama Medical Center Jichi Medical University approved the study. All participants and/or parents of guardians provided informed consent after receiving an explanation of the nature of the study and the possible consequences.

Disclosure

Dr Rina Takagi reports grants from Novartis Japan, outside the submitted work. The authors have no other competing interests related to this report.

Additional information

Funding

No funding or sponsorship was received for this study or publication of this article.