Preservation of the Foveal Avascular Zone in Achromatopsia Despite the Absence of a Fully Formed Pit
Year: 2020
Type: article
Study design: Observational Study
Abstract: Purpose: To examine the foveal avascular zone (FAZ) in patients with congenital achromatopsia (ACHM). Methods: Forty-two patients with genetically confirmed ACHM were imaged either with Optovue's AngioVue system or Zeiss's Plex Elite 9000, and the presence or absence of a FAZ was determined. For images where a FAZ was present and could be confidently segmented, FAZ area, circularity index, and roundness were measured and compared with previously published normative values. Structural optical coherence tomography images were acquired to assess the degree of foveal hypoplasia (number and thickness of inner retinal layers present at the fovea). Results: A FAZ was present in 31 of 42 patients imaged (74%), although no determination could be made for 11 patients due to poor image quality (26%). The mean ± SD FAZ area for the ACHM retina was 0.281 ± 0.112 mm2, which was not significantly different from the previously published normative values (P = 0.94). However, their FAZs had decreased circularity (P < 0.0001) and decreased roundness (P < 0.0001) compared to the normative cohort. In the patients with ACHM examined here, the FAZ area decreased as the number and thickness of the retained inner retinal layers increased. Conclusions: Our data demonstrate that despite the presence of foveal hypoplasia, patients with ACHM can have a FAZ. This is distinct from other conditions associated with foveal hypoplasia, which generally show an absence of the FAZ. In ACHM, FAZ formation does not appear to be sufficient for complete pit formation, contrary to some models of foveal development.
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,850
Funders: NIHR Biomedical Research Centre, Royal Marsden NHS Foundation Trust/Institute of Cancer Research, National Institute for Health and Care Research, Retina UK, A.G. Leventis Foundation, Alexander S. Onassis Public Benefit Foundation, Moorfields Eye Hospital NHS Foundation Trust, Moorfields Eye Charity, National Institutes of Health, National Institute on Aging, National Eye Institute, National Institute of General Medical Sciences, National Center for Research Resources, National Center for Advancing Translational Sciences
Awards: G2124338523, Retinal Versus Cortical Contributions to Vision Loss in Albinism, Medical Student Training in Aging and Injury Research, Multimodal Imaging of Photoreceptor Structure in Achromatopsia, Medical Scientist Training Program, J. NRSA Training Core, CONSTRUCTION OF VISION RESEARCH LABORATORIES, Clinical and Translational Science Award, Assessing Photoreceptor Structure and Function in Normal and Diseased Retinae
OpenAlex ID: W3082282492