Autorefraction versus subjective refraction in high astigmatism

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Accurate refractive error assessment is crucial for effective vision correction.
• High astigmatism presents unique challenges in refractive measurements.
• Comparing autorefraction and subjective refraction is essential for clinical practice.

Purpose of the Study:

• To compare subjective refraction data with auto-refraction findings in individuals with high astigmatism.
• To evaluate the agreement and correlation between two common refractive measurement methods.

Main Methods:

• A cross-sectional study was conducted in Iran using multistage random cluster sampling.
• Participants (8-15 years) underwent cycloplegic auto-refraction and subjective refraction (red-green test).
• Sphere, cylinder, spherical equivalent, J0, and J45 were analyzed for agreement and correlation.

Main Results:

• Mean differences between subjective and auto-refraction were observed for sphere (-0.18±0.76), cylinder (-0.36±0.40), and spherical equivalent (-0.36±0.79).
• High correlations were found (0.898-0.963) between the methods for all measured indices.
• Agreement decreased with increasing cylinder power, with better agreement in myopic individuals.

Conclusions:

• Autorefractometers tend to report higher average cylinder values than subjective refraction.
• Correlation between J0 and J45 values from both methods is limited in the 4-5 diopter cylinder range.
• Clinical consideration of measurement differences is important, especially for high astigmatism.