Subthreshold Micropulse Laser at Two Wavelengths for Juvenile X-Linked Retinoschisis: A Two-Patient Feasibility Study with 8-Month Follow-Up.

Background: Juvenile X-linked retinoschisis (XLRS; OMIM 300839) is an inherited retinal disorder characterized by foveal schisis and variable visual impairment. There is no approved disease-modifying treatment, and evidence for interventions targeting XLRS-associated macular changes remains limited. Objective: To assess the feasibility, short-term safety, and descriptive anatomical and functional outcomes of subthreshold micropulse laser (SMPL) delivered at two wavelengths in two brothers with molecularly confirmed XLRS. Methods: Two brothers aged 31 and 33 years, both hemizygous for the RS1 variant c.589C>T (p.Arg197Cys), underwent bilateral SMPL in a single session. Each right eye received 520-nm green SMPL (300 mW), and each left eye received 577-nm yellow SMPL (350 mW). The remaining parameters were matched, as follows: 100 µm spot diameter, 200-ms exposure, 5% duty cycle, zero spot spacing, and 400 confluent applications across the macula. Best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were assessed at baseline and at months 4 and 8. Results: Descriptively, individual-eye measurements showed heterogeneous anatomical and visual changes over follow-up. In patient 1, right-eye CFT changed from 485 to 466 and 153 µm, while BCVA changed from 3/10 to 4/10 and 6/10 at months 4 and 8, respectively. Left-eye CFT changed from 281 to 209 and 209 µm, while BCVA changed from 2/10 to 3/10 and 4/10. In patient 2, right-eye CFT changed from 488 to 250 and 453 µm, with BCVA changing from 2/10 to 4/10 and 4/10. Left-eye CFT changed from 398 to 249 and 498 µm, with BCVA changing from 2/10 to 3/10 and 3/10. No treatment-related adverse events or visible changes on infrared reflectance or fundus autofluorescence imaging were observed through month 8. Conclusions: A single bilateral SMPL session was feasible and was followed by transient or sustained anatomical and visual changes in these two patients. Because this uncontrolled case series included only two related participants and assigned wavelength by eye laterality with different power settings, it cannot establish efficacy or comparative wavelength superiority. The findings are hypothesis-generating and warrant evaluation in a prospective controlled study.