Flash Electroretinography as a Measure of Retinal Function in Myopia and Hyperopia: A Systematic Review.

Area of Science:

• Ophthalmology
• Neuroscience
• Vision Science

Background:

• Refractive errors like myopia and hyperopia are prevalent visual disorders.
• These conditions are significant risk factors for other ocular pathologies.
• Changes in ocular axial length, potentially influenced by retinal elements, are implicated in refractive error development.

Purpose of the Study:

• To systematically review literature on retinal function in human refractive error populations.
• To assess retinal function using global flash electroretinograms (gfERGs).
• To investigate the relationship between refractive errors and gfERG findings.

Main Methods:

• Systematic literature search across multiple databases (Medline, PubMed, Web of Science, Embase, Psych INFO, CINAHL).
• Inclusion criteria focused on human clinical refractive error populations, excluding case studies, comorbidities, drug trials, and reviews.
• Eight studies (N=552) with acceptable risk of bias were analyzed for demographic, refractive, and gfERG data.

Main Results:

• Myopia in humans is associated with attenuated gfERG photoreceptor (a-wave) and bipolar cell (b-wave) function.
• These findings align with observations in animal models of myopia.
• Interpretation of gfERG results for hyperopia was limited by inconsistent reporting across studies.

Conclusions:

• Myopia impacts retinal function, specifically affecting photoreceptor and bipolar cell activity.
• Consistent reporting of gfERG protocols and outcomes is crucial for future research on hyperopia.
• Standardized methodologies are needed to better understand retinal function in both myopia and hyperopia.