Comparison of retinal structure and schisis location in X-linked retinoschisis and enhanced S-cone syndrome.

PURPOSE: To provide a quantitative assessment of the primary retinal layers affected by macular cystoid spaces in X-linked retinoschisis (XLRS) and enhanced S-cone syndrome (ESCS).

METHODS

Twenty-two visually-normal controls, 14 XLRS and 7 ESCS (autosomal recessive inheritance) subjects participated. Macular B-scans were acquired by OCT and the thickness of the inner-nuclear layer (INL), outer-nuclear layer plus outer-plexiform layer (OPL+ONL), and photoreceptor outer segments (OS+) was calculated. ANOVA was used to compare mean thicknesses within each layer for the three subject groups.

RESULTS

Thirteen of 14 XLRS subjects and all 7 ESCS subjects had macular schisis by OCT. The INL was significantly thicker than normal for the XLRS group, but not significantly different from normal for the ESCS group. Conversely, the OPL+ONL was abnormally thick for all ESCS subjects and abnormally thin for all XLRS subjects. OS+ was significantly thinned for the XLRS group, but not significantly different from normal for the ESCS group.

CONCLUSION

In this sample of subjects, macular cystoid spaces were most apparent in the INL of XLRS subjects and in the OPL+ONL of ESCS subjects. Additionally, photoreceptor thinning was a characteristic of XLRS, which was less apparent in ESCS. These data provide insight into the location of macular cystoid spaces and highlight anatomical differences between XLRS and ESCS patients.