Sector-Based Regression Strategies to Reduce Refractive Error-Associated Glaucoma Diagnostic Bias When Using OCT and...

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Diagnostics

Background:

• Refractive errors, including myopia and hyperopia, can influence optical coherence tomography (OCT) and OCT angiography (OCTA) measurements.
• Accurate glaucoma diagnosis relies on precise interpretation of retinal nerve fiber layer thickness (NFLT), nerve fiber layer plexus capillary density (NFLP-CD), and ganglion cell complex thickness (GCCT).

Purpose of the Study:

• To investigate how refractive error affects sectoral diagnostic parameters obtained via OCT and OCTA.
• To evaluate the impact of ametropia on specific ocular structures relevant to glaucoma detection.

Main Methods:

• Cross-sectional study of 791 participants (1339 eyes) from the Hong Kong FAMILY cohort.
• Stratification of eyes by spherical equivalent refraction: high myopia, low myopia, emmetropia, and hyperopia.
• Analysis of sectoral NFLT, NFLP-CD, and GCCT using multivariable broken stick regression models, with adjustments for age, sex, and signal strength.

Main Results:

• Ametropia-related covariates significantly affected most NFLT sectors, the inferior GCCT hemisphere, and half of NFLP-CD sectors more than global parameters.
• Elevated false-positive rates were observed in specific sectors due to refractive error.
• Sector-specific axial length (AL) and spherical equivalent (SE) adjustments effectively reduced these elevated false-positive rates.

Conclusions:

• Optical magnification due to refractive error has a more pronounced effect on sectoral OCT/OCTA parameters than global ones.
• Individualized, sector-specific AL and SE adjustments are crucial for mitigating magnification bias.
• Implementing these sector-based adjustments in commercial OCT systems can improve glaucoma diagnostic accuracy by reducing refractive error-related false positives.