Phenotypic expressions of the optic disc in primary open-angle glaucoma

Area of Science:

• Ophthalmology
• Glaucoma Research
• Optic Nerve Imaging

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
• Understanding the phenotypic variations in the optic nerve is crucial for diagnosing and managing POAG.
• Optic nerve head morphology provides key insights into glaucoma progression.

Purpose of the Study:

• To identify and classify distinct phenotypes of the optic nerve in patients with POAG.
• To analyze the demographic and ocular characteristics associated with each identified phenotype.
• To establish a basis for improved patient stratification and care in POAG management.

Main Methods:

• A retrospective analysis of 885 eyes from 885 POAG patients was conducted.
• Optic disc photographs were classified into six phenotypes by glaucoma specialists: concentric rim thinning, focal rim thinning, acquired pit of the optic nerve (APON), tilted, extensive peripapillary atrophy (PPA), and broad rim thinning.
• Statistical analyses, including Kruskal-Wallis and Wilcoxon rank sum tests, were used to compare phenotypic groups.

Main Results:

• The most prevalent phenotype was focal thinning (45%), followed by concentric thinning (18%) and broad thinning (17%).
• Significant associations were found between phenotypes and factors such as female sex (focal thinning), myopia, Asian race, and younger age (tilted phenotype).
• Concentric thinning showed correlations with thicker retinal nerve fiber layer (RNFL), higher mean deviation (MD), and lower pattern standard deviation (PSD) compared to broad thinning.

Conclusions:

• Six distinct optic nerve phenotypes were identified in POAG patients.
• These phenotypes exhibit significant demographic and ocular differences.
• Further refinement of these phenotypes may enhance genetic association studies and personalize patient care strategies for POAG.