Abstract
Purpose :
To investigate key clinical characteristics in patients with molecularly confirmed foveal hypoplasia
Methods :
This was a retrospective study of a series of 58 patients with conditions associated with foveal hypoplasia. Patients were ascertained from the New Zealand Database of Inherited Retinal and Optic Nerve Disease. Detailed phenotyping included best corrected visual acuity and retinal imaging with Spectralis optical coherence tomography (OCT).
Only patients with molecularly confirmed diagnoses, OCT imaging of sufficient quality to grade the degree of foveal hypoplasia and without other causes for reduced vision were included in the analysis. Foveal hypoplasia grading was performed according to the Leicester Grading System for Foveal Hypoplasia. Statistical analysis was performed using the Mann-Whitney U test and the Kruskal-Wallis test.
Results :
33 patients from 30 families were included in analysis. Diagnoses included oculocutaneous albinism, OCA (n=14), forms of cone-rod synaptic disorders also known as congenital stationary night-blindness (CSNB), (n=12), Stickler syndrome (n=5), PAX6 related ocular dysgenesis (n=1) and isolated foveal hypoplasia (n=1).
All patients with OCA had nystagmus except for one who had grade 4 foveal hypoplasia and BCVA of R&L 0.1 logMAR (20/25 Snellen).
Patients with CSNB did not fit the Leicester Grading System, all having shallow foveal pits but otherwise normal foveal architecture except for one patient with mild preservation of foveal plexiform layers. Visual acuity varied widely from 0.1 to 0.9 logMAR (20/25 to 20/160 Snellen). Comparison of patients with (n=5) and without nystagmus (n=7) found no significant difference (p=0.17).
Mild foveal hypoplasia was found in Stickler syndrome type 1 related to variants in COL2A1 with 3 of 5 patients having grade 1b or 2 hypoplasia.
Average visual acuity for patients with OCA and Sticklers syndrome was significantly better with foveal hypoplasia grades 0-2 compared to grades 3-4 (p=0.00003).
Comparison of visual acuity between OCA, CSNB and Stickler syndrome found no significant difference (p=0.25).
Conclusions :
A number of heterogeneous disorders have associated abnormal foveal development. In general the degree of foveal hypoplasia correlates with visual acuity.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.