Outer nuclear layer thickness as a biomarker for photoreceptor function in pachychoroid spectrum disorders

Area of Science:

• Ophthalmology
• Retinal Diseases
• Optical Coherence Tomography (OCT)

Background:

• Pachychoroid pigment epitheliopathy (PPE) and pachychoroid neovasculopathy (PNV) are conditions affecting the choroid and retina.
• Assessing photoreceptor function is critical for understanding disease progression and visual outcomes.

Purpose of the Study:

• To evaluate the outer nuclear layer (ONL) thickness as a biomarker for photoreceptor function in PPE and PNV.
• To determine the impact of pachychoroid features, neovascularization, and exudation history on photoreceptor function.

Main Methods:

• Retrospective analysis of 101 eyes with pachychoroid features and 34 control eyes.
• OCT angiography to categorize groups into PNV and PPE, with PNV further stratified by exudation history.
• Measurement of retinal and choroidal layer thicknesses and best-corrected visual acuity (BCVA), with correlation analysis.

Main Results:

• ONL thickness significantly differed across groups, correlating linearly with BCVA.
• PNV eyes had the thinnest ONL, followed by PPE, and then controls.
• Exudation in PNV eyes was associated with thinner ONL and worse BCVA.

Conclusions:

• ONL thickness is a reliable quantitative biomarker for photoreceptor function in PNV and PPE.
• Photoreceptor function is impaired by pachychoroid features, neovascularization, and exudation.
• Prompt treatment of neovascularization or exudation is vital to prevent photoreceptor loss.