Luminance Thresholds and Their Correlation With Retinal Structure in X-Linked Retinoschisis

Area of Science:

• Ophthalmology
• Neuroscience
• Genetics

Background:

• X-linked retinoschisis (XLRS) is a genetic disorder affecting retinal structure and function.
• Understanding visual perception in XLRS requires analyzing luminance thresholds across different adaptation states.

Purpose of the Study:

• To comprehensively analyze light- and dark-adapted luminance thresholds in XLRS patients.
• To investigate the association between these visual thresholds and retinal structural integrity.

Main Methods:

• Measured luminance thresholds at multiple visual field locations and adaptation levels in XLRS patients and controls.
• Utilized optical coherence tomography (OCT) to quantify outer nuclear layer (ONL+) and outer segment (OS+) thickness.
• Employed a linear structure-function model to correlate visual thresholds with retinal layer thickness.

Main Results:

• XLRS patients showed normal peripheral thresholds but elevated perifoveal and parafoveal thresholds, especially under dark-adapted and high illuminance conditions.
• Foveal thresholds were mostly normal in the dark but elevated at high illuminances.
• Threshold-versus-illuminance curves in XLRS were steeper, resembling normal peripheral curves, and retinal thickness (ONL+ × OS+) predicted thresholds across most locations.

Conclusions:

• Visual threshold abnormalities in XLRS are intricate, influenced by adaptation level and visual field location.
• Macular function in XLRS appears analogous to the peripheral function in healthy individuals.
• Retinal layer thickness is a key determinant of visual function in XLRS.