ORIGINAL ARTICLES   

Minerva Oftalmologica 2011 March;53(1):7-11

Copyright © 2011 EDIZIONI MINERVA MEDICA

language: Italian

Incidence of high myopia in italian patients with retinitis pigmentosa

Testa F., Rossi S., Di Iorio V., Orrico A., Dell’Aversana Orabona G., Di Perna L., Attanasio M., Della Corte M., Sbordone S., Bifani M.

Dipartimento di Oftalmologia, Seconda Università di Napoli, Napoli, Italia

Aim. Retinitis pigmentosa (RP) comprises a heterogeneous group of inherited disorders, characterized by progressive degeneration of photoreceptors, that affects first the rods and then the cones. In relation to the phenotypic manifestations non syndromic – RP and syndromic – RP, associated with extraocular alterations can be distinguished; furthermore a careful ophthalmologic evaluation can classify “typical” and “atypical” forms of RP (Retinitis punctata albescent, sector RP, RP pericentral, RP without pigment). The purpose of this study was to assess the impact of high myopia (spherical equivalent [SE] > 6D)in patients with RP and, in particular, to observe the associated clinical manifestations.
Methods. The study included 1700 patients with clinical and genetic diagnosis of retinitis pigmentosa, recruited by the Referral Center For Hereditary Retinopathies of the Second University of Naples. A full ophthalmologic evaluation, including central visual acuity measurements with Snellen charts, Goldmann visual field, fundus exam and standard ERG was carried out on all patients.
Results. Clinical investigation, conducted on 1700 patients revealed the classical form of RP in 86% of patients, a fundus characterized by the presence of rare accumulations of typical and atypical pigment in 6.9% of patients and RP without pigment in 7% of cases. Furthermore, the high myopia was present in 36 out of 1700 patients, about 2%.
Conclusion. Our study represents one of the few studies in the literature on RP associated with high myopia with the recruitment of approximately 1700 patients. The results demonstrate a 30% incidence of high myopia associated with RP without. Statistically significant percentage considering the overall incidence of this form. Such a high incidence is probably related to the retinal pigmented epithelium dystrophy due to high myopia that can mask typical signs of RP.