High Myopia and Retinal Dystrophy Point to Inherited Retinopathy

High myopia and retinal dystrophy that has an early onset and slowly progresses over decades may be signs of retinol binding protein 3 (RBP3)-retinopathy, according to a poster presented at the American Society of Retina Specialists meeting, held in Seattle, July 28 to August 1, 2023. 

Researcher Michalis Georgiou, MD, PhD, an ophthalmology resident at the University of Arkansas Medical Science, led a team in investigating the disease’s natural history and clinical phenotype through a multi-center, international, retrospective, consecutive observational study. This is the first time the disease’s natural history has been investigated, according to the presentation.

They examined adults and children with molecularly confirmed RBP3 retinopathy from 3 tertiary referral centers in the UK, the US, and Japan. They analyzed genetics, clinical findings, optical coherence tomography (OCT), fundus autofluorescence (FAF), and electroretinography, both cross-sectionally and longitudinally.

Among 12 patients (mean age, 21.4 years at baseline, 5 women) from 10 families, the researchers found 10 novel disease-causing RBP3 variants. Ten cases were homozygous. 

At baseline, the best corrected visual acuity (BCVA) was 0.48 logarithm of the minimum angle of resolution (logMAR), and it decreased to a mean 0.46 logMAR after a mean follow-up of 12.6 years. 

The patients’ mean spherical equivalent was -16.0 diopters (D), without significant difference between eyes or anisometropia. They had reached myopia by age 7 years. All had choroidal thinning. Fundus pigmentary changes were absent in the 4 youngest patients, but the rest had at least some mid-peripheral pigmentation and macular changes. Among older patients, FAF ranged from areas of increased signal to advanced atrophy. Older patients had more atrophy. Two patients presented with cystoid macular edema.

“RBP3-retinopathy should be considered in adults and children with high myopia and retinal dystrophy, with or without nyctalopia,” according to the poster.