The hereditary types and clinical characteristics of 137 patients with retinitis pigmentosa in Ningxia

Abstract

Objective To observe the hereditary types and clinical characteristics of 137 patients with retinitis pigmentosa (RP) in Ningxia. MethodsOne hundred and thirty-seven patients with RP who diagnosed by the examinations of visual acuity, optometry, direct or indirect ophthalmoscope, visual field,optical coherence tomography (OCT) and electroretinogram were enrolled. The hereditary types and clinical characteristics were analyzed according to the family history and the results of ophthalmologic examinations.Results One hundred and thirty-seven patients included 29 autosomal dominant RP (ADRP) patients from 8 families (7.4％), 16 autosomal recessive RP (ARRP) patients from 15 families (13. 9％), 10 X-linked RP (XLRP) from 3 families (2.8％), and 82 simplex RP (SRP) patients (75.9％). There were 15consanguineous marriage families out of 26 families with RP history (57.7 ％). The patients were classified as typical RP (102 patients, 74.5％) and atypical RP (35 patients, 25.5％). All the ADRP and XLRP patients showed typical clinical features of RP. Ten (62.5％) of ARRP patients and 53 (64.6％) of SRP patients had typical features of RP. Six (37.5％) of ARRP patients and 29 (35.4％) of SRP patients had atypical features of RP. Among atypical RP patients, 17 (48. 6％) patients were non-pigmented RP which including 3 patients were misdiagnosed as amblyopia during childhood. The logarithm of minimal angle of resolution (logMAR) best corrected visual acuity (BCVA) of ADRP patients was 1.04±0.51 at the age older than 51 years, while the BCVA of ARRP and XLRP patients were 0. 92+0. 61 and 1. 70±0. 02 respectively at 21 to 30 years of age. One hundred and twenty-three (89. 8%) patients suffered from varying degrees of myopia. OCT showed that the average thickness of macular fovea in ADRP patients was ( 185. 73 + 1. 23) μm at the age older than 51 years, while in ARRP and XLRP patients were (173. 21 ± 0. 98) and (170. 49+1. 15) μm respectively at 21 to 30 years of age. Conclusions ADRP and XLRP are typical RP. All atypical RP are ARRP and SRP. Non-pigmented RP are mainly seen in atypical RP which often misdiagnosed as amblyopia during childhood. The photoreceptors in macula are damaged in the early stage and the decline of visual acuity occurred at 21 to 30 years of age in patients with ARRP and XLRP. The ADRP patients has late slower decline of visual acuity and retain some visual acuity at the age older than 51 years. Key words: Retinitis Pigmentosa/genetics; Disease attributes