X-linked Hereditary Retinoschisis.

AN X-linked degenerative retino-choroidal disease, hereditary retinoschisis, has been identified in the last 10 years. In milder cases the disease takes the form of radial macular degeneration, but in severe cases a grey sheet-like veil is attached to the detachment in the retinal vasculature, especially in the lower temporal quadrant. In differential diagnosis, according to Ricci (1960), a dominant hereditary hyaloid-retinal degeneration (Wagner, 1938) and a recessive hereditary hyaloid-tapeto-retinal degeneration (Favre, 1958) should be borne in mind. Genealogical tables covering several generations have been described by The last described a 13-year-old girl-possibly a latent carrier-with cystic (perhaps traumatic) macular degeneration. Rieger (1941) described a girl in whom the pathological picture was reminiscent of retinoschisis, but gave no genealogical or genetic details. In SouthWest Finland, a family has been found (Fig. 1, opposite), which shows a progressive disease from childhood, with reduced vision, slight hemeralopia, restricted visual fields, and a similar condition of the fundus. Cases Examined PROPOSITA V.9, a woman aged 44, had always had poor sight which had deteriorated gradually since infancy. The visual acuity in the right eye was 0-35, with + 3 D sph.,-1 5 D cyl., axis 1100. There was opacity of the posterior lens capsule (Fig. 2, overleaf). The left eye showed a slight Y-shaped opacity of the posterior lens capsule, and the fundus appearance was similar. The visual acuity was 0 15 with +3 35 D sph. HER SONS VI.21. The visual acuity in the right eye was 0 35, with-0 075 D sph., +1 75 D cyl., axis 0°. In the lower part of the fundus, nasally and temporally, was a thin veil showing individual retinal vessels and large ruptures.