Jpn J Ophthalmol. 2020 Sep;64(5):485-496. doi: 10.1007/s10384-020-00752-1. Epub 2020 Jul 6.

ABSTRACT

PURPOSE: To report the clinical course and high resolution images of autosomal recessive retinitis pigmentosa (RP) associated with a variant of the RP1 gene (c.4052_4053ins328/p.Tyr1352Alafs*9; m1), a high frequency founder variant in Japanese RP patients.

STUDY DESIGN: Retrospective case series.

METHODS: Nine patients from 5 unrelated Japanese families were studied. Five patients had the m1 variant homozygously, and 4 patients had the m1 variant compound heterozygously with another frameshift variant (c.4196delG/p.Cys1399Leufs*5). Ophthalmic examinations including adaptive optics (AO) fundus imaging were performed periodically.

RESULTS: The fundus photographs, fundus autofluorescence (FAF) images, and optical coherence tomographic (OCT) images indicated severe retinal degeneration in all the patients involving the macula even at a young age (20 s). The areas of surviving photoreceptors in the central macula were seen as hyper-autofluorescent regions in the FAF images and preserved outer retinal structure in the OCT images; they were identifiable in the AO fundus images in 8 eyes. The borders of the surviving photoreceptor areas were surrounded by hyporeflective clumps, presumably containing melanin, and the size of these areas decreased progressively during the 4-year follow-up period. The disappearance of the surviving photoreceptor areas was associated with complete blindness.

CONCLUSION: Patients with RP associated with the m1 variant have a progressive and severe retinal degeneration that begins at an early age. Monitoring the surviving photoreceptor areas by AO fundus imaging can provide a more precise pathological record of retinal degeneration.

PMID:32627106 | DOI:10.1007/s10384-020-00752-1