Why this small study matters

Juvenile X-linked retinoschisis (XLRS) is an inherited retinal disease that primarily affects males. It is caused by changes in the RS1 gene and is marked by splitting, or “schisis,” within layers of the retina—especially at the macula, the central area needed for reading, recognizing faces, and seeing fine detail. The resulting fluid-filled spaces can alter retinal structure and contribute to variable loss of central vision.

There is currently no approved disease-modifying treatment for XLRS. This makes studies exploring ways to improve XLRS-associated macular changes important to patients, families, and researchers. A 2026 feasibility study in the Journal of Clinical Medicine examined whether a form of gentle laser treatment, called subthreshold micropulse laser (SMPL), could be delivered safely to the macula of two brothers with molecularly confirmed XLRS.

The report is very early research: it involved only two participants and was designed to explore feasibility, short-term safety, and possible signals of anatomical or visual change over eight months. Even so, it offers a detailed look at an approach that may merit more rigorous evaluation.

What is subthreshold micropulse laser?

Traditional retinal laser treatment creates visible, permanent burns in targeted tissue. By contrast, subthreshold micropulse laser delivers energy in very brief pulses, separated by “off” periods. The goal is to provide a biological stimulus without producing clinically visible retinal damage.

In this study, both brothers received SMPL in both eyes during one treatment session. The right eyes were treated with a 520-nanometer green laser at 300 milliwatts, while the left eyes received a 577-nanometer yellow laser at 350 milliwatts. Other settings were matched between eyes, including a 100-micrometer spot size, 200-millisecond exposure, 5% duty cycle, and 400 closely placed applications across the macula.

The researchers followed two main outcomes:

  • Central foveal thickness (CFT): a measurement from retinal imaging that reflects the thickness of the very center of the macula.
  • Best-corrected visual acuity (BCVA): vision measured while using the best available glasses or contact lens correction.

What did the researchers observe?

The participants were brothers aged 31 and 33 years. Both carried the same RS1 variant, c.589C>T (p.Arg197Cys), in the hemizygous state, meaning they had one altered copy of the RS1 gene on their X chromosome.

Changes in retinal thickness and vision varied substantially between eyes and over time. This variation is a central finding of the study.

In the first participant, central foveal thickness in the green-laser-treated right eye changed from 485 micrometers at baseline to 466 micrometers at four months, then to 153 micrometers at eight months. Vision in that eye improved from 3/10 at baseline to 4/10 at four months and 6/10 at eight months. In his yellow-laser-treated left eye, thickness declined from 281 to 209 micrometers and remained 209 micrometers at eight months, while vision improved from 2/10 to 3/10 and then 4/10.

In the second participant, the right eye showed a decrease in thickness from 488 to 250 micrometers at four months, followed by an increase to 453 micrometers at eight months. Vision improved from 2/10 to 4/10 and remained 4/10. In the left eye, thickness changed from 398 to 249 micrometers at four months, then increased to 498 micrometers by month eight. Vision rose from 2/10 to 3/10 and remained at that level.

Put simply, some eyes showed a reduction in central retinal thickness that persisted through eight months, while others showed an early decrease that was not maintained. Visual acuity improved in every eye in this small series, but the degree of improvement differed.

Importantly, the authors reported no treatment-related adverse events through month eight. They also found no visible treatment-related changes on infrared reflectance imaging or fundus autofluorescence imaging, two methods used to assess retinal appearance.

What the findings do—and do not—tell us

This study shows that bilateral SMPL treatment using these settings was feasible in two adults with XLRS and did not produce observed short-term safety concerns in the eight-month follow-up period. It also raises the possibility that SMPL could influence the macular changes associated with XLRS in some eyes.

However, the study cannot show that the laser caused the observed improvements. XLRS can vary over time, and there was no untreated comparison group. The participants were related and had the same RS1 variant, so their outcomes may not represent the broader XLRS community.

The report also cannot determine whether green or yellow laser is better. Wavelength was assigned according to eye laterality—green for right eyes and yellow for left eyes—and the two wavelengths used different power settings. A larger study would need to compare treatments in a planned, controlled way.

Where this fits in the XLRS research landscape

For now, SMPL remains an investigational approach for XLRS-associated macular changes rather than an established treatment. The next step is a prospective controlled study involving more participants, standardized outcome measures, and longer follow-up. Such a trial could clarify how durable any anatomical changes are, whether changes in retinal thickness reliably translate into meaningful visual benefit, and which patients may be most likely to respond.

At the same time, XLRS research continues to include efforts aimed at the underlying genetic cause, as well as studies of approaches that may preserve or improve retinal structure and function. This two-patient report does not provide a final answer, but it contributes a useful early signal: carefully delivered micropulse laser deserves further study as one possible tool in the evolving treatment landscape for XLRS.