Low vision correction in retinitis pigmentosa and associated diseases

Retinitis pigmentosa was considered unfavorable for low vision corrections before it was recognized that the term retinitis pigmentosa as frequently used referred to a group of disease entities including Leber's congenital amaurosis, centro-peripheral dystrophy, typical retinitis pigmentosa and Usher's syndrome. The success rate for use of optical aids was Leber's congenital amaurosis 66%, centro-peripheral dystrophy 75%, typical retinitis pigmentosa 95%. This data shows that the poor success rate is not due to the constricted visual field but to the combined central and peripheral visual impairment. The type of aids most commonly prescribed were spectacle corrections, bifocals, hand magnifiers and the Visolett (paperweight type magnifier). The Visolett (paperweight type magnifier) has proven to be the most suitable non-spectacle magnifier used by itself, or in addition to a spectacle magnifier. Telescopic spectacles were rarely found to be of any value. The data showed that the correction of these diseases consisted of a refraction and strong reading addition in 65% of the patients.