Myopia and Other Refractive Error and Their Relationships to Glaucoma Screening

Area of Science:

• Ophthalmology
• Optic Nerve Head Imaging
• Glaucoma Research

Background:

• Refractive error influences optic nerve head (ONH) morphology.
• High myopia presents unique challenges for diagnosing glaucomatous optic neuropathy (GON).
• Understanding ONH changes in myopia is crucial for accurate glaucoma screening.

Purpose of the Study:

• To evaluate screening strategies for GON based on refractive error.
• To specifically address screening considerations in highly myopic individuals.
• To identify key morphological parameters for detecting GON in myopia.

Main Methods:

• Review of studies on myopic ONH anatomy.
• Analysis of research on the relationship between GON and axial myopia.
• Inclusion of investigations on morphological parameters in myopic eyes.

Main Results:

• Refractive error is not a significant glaucoma risk factor in hyperopia to moderate myopia.
• Moderate myopia can cause temporal displacement of Bruch's membrane opening, leading to parapapillary gamma zone and smaller horizontal disk diameter.
• In highly myopic eyes (axial length > 26.5 mm), GON prevalence increases sharply, exceeding 50% in extreme cases.
• Enlarged optic disk and large parapapillary delta zone are associated with GON in high myopia.
• Nonglaucomatous optic neuropathy is linked to larger gamma zone and longer axial length, possibly due to nerve fiber stretching.

Conclusions:

• Long axial length, large optic disk, and large parapapillary delta zone are effective screening criteria for GON in highly myopic eyes.
• Careful assessment is needed in moderate myopia to avoid overlooking GON despite smaller optic disks.
• Axial elongation-related factors may contribute to both glaucomatous and nonglaucomatous optic neuropathies in myopia.