Visual Acuity Examination Methodology in Keratoconus

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Visual acuity is crucial for assessing vision in keratoconus patients.
• Published research on keratoconus often includes visual acuity measurements.
• Standardized reporting of visual acuity testing is essential for reliable data.

Purpose of the Study:

• To analyze the methodology of visual acuity testing in keratoconus research.
• To identify common practices and potential shortcomings in visual acuity assessment.
• To evaluate the validity of converting Snellen chart results to the logMAR scale.

Main Methods:

• Systematic review of 295 articles on keratoconus published between 2017 and 2022.
• Analysis focused on visual acuity testing methodologies described.
• Examination of Snellen chart usage and logMAR scale conversions.

Main Results:

• The Snellen chart was the most frequently cited tool for visual acuity testing.
• 150 out of 295 articles failed to describe their visual acuity testing methodology.
• 68 articles used conversions from Snellen to logMAR, raising concerns about validity.

Conclusions:

• Inconsistent reporting of visual acuity testing methods in keratoconus studies is prevalent.
• Lack of methodological detail and questionable logMAR conversions can lead to misinterpretation of visual acuity data.
• Standardization of visual acuity assessment protocols is needed for accurate keratoconus research.