Juvenile X-linked retinoschisis (XLRS, OMIM 31270) is a vitreoretinal dystrophy that manifests early in life (as early as 3 months of age)²² and has no associated nonocular findings. Intraretinal cysts form in the macula, and splitting of the retinal layers occurs in peripheral retina (figures 73.1 and 73.2). The macular changes frequently are in the form of a spoke-wheel pattern of perifoveal cysts and may result in a visual acuity of 20/60 or less. Patients tend to be hyperopic.¹¹ Substantial peripheral visual field loss can occur. The term retinoschisis was introduced by Wilczek in 1935.²⁸

Figure 73.1.  

Fundus photograph of XLRS-affected male with juvenile retinoschisis showing spoke-wheel pattern of foveal cysts covering an area of approximately one disk diameter.

Figure 73.2.  

Fundus photograph of XLRS-affected male with peripheral schisis cavity, which occurs in 50% of affected males.

The condition is limited nearly exclusively to males. Female carriers essentially never show macular or retinal pathology or suffer visual symptoms, but in rare cases, carriers may have macular or peripheral retinal changes, presumably on the basis of Lyonization of the trait.⁹

XLRS is one of the more common causes of juvenile macular degeneration in males, with a prevalence of 1:5,000 to 1:25,000. Affected males typically are identified by early grade-school age owing to reduced visual acuity. Males initially complain of reduced visual acuity, not poor night vision or loss of peripheral vision. In many cases, the reduced visual acuity stabilizes by the teenage years in affected males and then remains constant into middle age. Macular atrophy may begin in late middle age and progress toward legal blindness (20/200) in affected males. Vitreous hemorrhage and full-thickness retinal detachment occurs occasionally, and successful surgical repair is infrequent.

While the fundus appearance of XLRS may be diagnostic in affected males, the presentation can be confusing in some cases, requiring additional testing with electroretinography. This will be most helpful in the males who have progressed beyond the typical spoke-wheel pattern and present with a bilateral maculopathy, with or without areas of peripheral schisis. A fluorescein angiogram may also be helpful in differentiating XLRS from autosomal-recessive Stargardt macular dystrophy, which exhibits a silent or dark choroid. Younger patients typically show a normal angiogram, although older patients with XLRS may exhibit changes in the retinal pigment epithelium, including relative window defects in the macula (figure 73.3). Occasionally, patients exhibit a change in color immediately or shortly after light onset with dark adaptation (Mizuo phenomenon).⁵ This phenomenon disappears with vitrectomy and removal of the posterior vitreous face.¹⁵

Figure 73.3.  

Intravenous fluoroscein angiogram of XLRS-affected male with abnormal RPE and showing a typical central fluoroscein staining due to RPE thinning.