Optical coherence tomography biomarkers in MYO7A-inherited retinal dystrophy: longitudinal study in pediatric patients

• Published in: Graefe's archive for clinical and experimental ophthalmology Vol. 262; no. 10; pp. 3375 - 3384
• Main Authors: Subirà, Olaia, Català-Mora, Jaume, del Prado, Cristina, Díaz-Cascajosa, Jesús, Barraso Rodrigo, Marina, Cobos, Estefanía, Aguilera, Cinthia, Esteve-Garcia, Anna, García-Arumí, José, Caminal, Josep M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2024; Springer Nature B.V
• Subjects: Acuity; Biomarkers; Edema; Epithelium; Medicine; Medicine & Public Health; Ophthalmology; Pediatrics; Photoreceptors; Retina; Retinal degeneration; Retinal pigment epithelium; Tomography; Usher's syndrome; mutations; Rod-cone dystrophy; Retinitis pigmentosa; Usher syndrome; MYO7A mutations
• ISSN: 0721-832X; 1435-702X; 1435-702X
• DOI: 10.1007/s00417-024-06545-3

Purpose This study aims to answer a key question: is MYO7A -inherited retinal dystrophy ( MYO7A -IRD) a photoreceptor-first or retinal pigment epithelium-first disease? A second aim was to determine the most useful biomarkers to monitor disease progression in pediatric patients with Usher syndrome type 1B (USH1) secondary to MYO7A mutation. Methods Fifty-two eyes from 26 patients with genetically-confirmed MYO7A -IRD underwent swept-source optical coherence tomography (SS-OCT). Structural abnormalities were evaluated and correlated with follow-up time and best corrected visual acuity (BCVA). All patients were evaluated at baseline and after ≥ 40 months of follow-up. Results The mean (SD) patient age was 9.92 (± 4.1) years. Mean follow-up time was 43 (± 3.2) months. At the final evaluation, the most common qualitative abnormalities in the subfoveal area were alterations in the photoreceptor outer segments (76.9% of eyes) and in the interdigitation zone (IZ) (80.8%). The presence of cystoid macular edema at baseline was independently associated with worse BCVA at the final assessment (increase in LogMAR estimate = 0.142; t(45.00) = 2.78, p  = 0.009). The mean width of the ellipsoid and interdigitation zones decreased significantly (by 668 μm and 278 μm, respectively; both p  < 0.001). Conclusion This study shows that disruption of the photoreceptor outer segments and the IZ are the first alterations detected by SS-OCT in the early phases of MYO7A -IRD. These data highlight the potential value of measuring the width of the ellipsoid and IZ to evaluate disease progression. These findings also demonstrate the utility of monitoring for the emergence of cystic lesions as biomarkers of worse visual prognosis in patients with MYO7A -IRD.