Objectives: To assess the phenotypic variation and visual prognosis of affected males with X-linked retinoschisis.
Design: Patients were ascertained from clinical geneticists and ophthalmologists in the United Kingdom. Genetic linkage analysis was carried out using polymorphic microsatellite markers from the Xp22 region of the X chromosome.
Patients: Fifty-six males from 16 British families with X-linked retinoschisis.
Results: Best-corrected visual acuity ranged from 20/20 to 20/600; 14 (25%) of the patients saw 20/40 or better, and 27 (55%) read N6 or better. Visual acuity was poorer in older patients (chi 2 =30.4, df=4, P<.001). Macular abnormalities were seen in all eyes. Foveal schisis was the most common abnormality seen in patients younger than 40 years (73 eyes [83%]), but in older patients a blunted foveal reflex or pigmentary atrophy was more common (17 eyes [85%]). Peripheral retinoschisis was seen in 40 (71%) of the patients. Vitreous hemorrhage occurred in 12 (21%) and retinal detachment in nine (16%) of the patients. Four eyes were blind as a result of retinal detachment.
Conclusions: Although no evidence exists for genetic heterogeneity in X- linked retinoschisis, there is wide phenotypic variation. The most serious sight-threatening complications are vitreous hemorrhage and retinal detachment. In uncomplicated cases, the prognosis for vision is good, although deterioration of vision occurs in the fourth and fifth decades of life because of macular atrophy.