Warwick AN, Shawkat F, Lotery AJ. Retinitis pigmentosa and bilateral cystoid macular oedema in a patient heterozygous for the RIM1 mutation previously associated with cone-rod dystrophy 7.
Ophthalmic Genet 2016;
38:178-182. [PMID:
27176872 DOI:
10.1080/13816810.2016.1183215]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND
Autosomal dominant cone-rod dystrophy 7 (CORD7) has been previously associated with the RIM1 c.2459G>A (Arg820His) mutation. Cystoid macular oedema (CMO) is a rare feature of CORD and has not been described in CORD7. We report a patient who was heterozygous for the RIM1 mutation with bilateral CMO and who manifested a retinitis pigmentosa phenotype.
MATERIALS AND METHODS
The patient's medical notes were retrospectively reviewed over an 18-month period. Genetic testing was performed by next generation sequencing for a panel of 176 genes associated with retinal dystrophy.
RESULTS
A 34-year-old man presented with a 5-year history of bilateral floaters and blurred vision. Visual acuity was 20/23 and 20/33 in the right and left eyes, respectively. Optical coherence tomography scans revealed bilateral CMO. Goldmann visual field tests detected mid-peripheral ring scotomas. Electrodiagnostic testing was overall consistent with a primary photoreceptor abnormality involving both rods and cones. Subsequent genetic testing identified heterozygosity for the RIM1 c.2459G>A (Arg820His) mutation. Various treatments for CMO were trialled unsuccessfully. However, at his latest clinic appointment the CMO had partially improved following topical brinzolamide therapy. Most recent visual acuity was 20/25 in the right eye and 20/24 in the left eye.
CONCLUSIONS
This is the first reported case of bilateral CMO in association with the RIM1 mutation. Overall, our findings were more consistent with a phenotype of retinitis pigmentosa. This could imply that the RIM1 mutation causes diverse retinal dystrophies, or that the previously described CORD7 phenotype resulted from a different variant on the same haplotype.
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