# A modified partition of peripapillary atrophy in high myopia based on optical coherence tomography

## TL;DR

This study uses OCT imaging to refine the classification of peripapillary atrophy in high myopia, identifying key features that correlate with disease progression.

## Contribution

A modified OCT-based partition of peripapillary atrophy in high myopia, revealing new zoning features linked to clinical parameters.

## Key findings

- Modified PPA zoning features (PPA1-4, SCA, SFCA) correlate with longer axial length and advanced fundus changes in HM.
- PPA1 and SCA are strongly associated with BCVA, axial length, and spherical equivalent in HM patients.
- Measurement consistency of modified PPA features was validated using the Bland–Altman method.

## Abstract

This study investigates morphological changes in peripapillary atrophy (PPA) in high myopia (HM) patients, aiming to refine PPA zoning characteristics to enhance clinical diagnosis and treatment of HM.

This study is categorized as a retrospective cross-sectional model.

We retrospectively reviewed 172 patients (316 eyes) with comprehensive medical records, categorizing them into a pathological myopia (PM) cohort—subdivided into PM1 (≥30 mm), PM2 (≥28 and <30 mm), PM3 (<28 mm)—and a simple HM group, based on fundus pathology and axial length (AL). We collected data on spherical equivalent (SE), best corrected visual acuity (BCVA), intraocular pressure (IOP), AL, and posterior optical coherence tomography (OCT). For posterior OCT, we manually measured improved landmark features based on the original PPA zoning: Scleral Curvature Angle (SCA), Scleral Flange Curvature Angle (SFCA), PPA1-4 zone, scleral flange length (SFL), and mean scleral flange thickness (MSFT). The Bland–Altman method assessed measurement consistency, and statistical comparisons were made of the modified PPA feature parameters across the groups.

An increase in AL and progression from simple HM to PM were associated with increases in age, AL, and IOP, along with decreases in BCVA and SE across all groups. The parameters SCA, SFCA, and PPA1-4 zones showed a general increase, whereas MSFT differences were not statistically significant (p > 0.05). In multiple factor linear regression analysis, PPA1 and SCA were strongly correlated with BCVA, AL, and SE (p < 0.01).

The modified PPA partition based on OCT imaging identifies 6 key zoning features: PPA1-4, SCA, and SFCA. These are correlated with longer AL and advanced fundus changes in HM patients. In particular, PPA1 and SCA emerge as vital indicators for assessing HM conditions using OCT imaging.