Repeatability and reproducibility of manifest refraction

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Accurate refractive measurements are crucial for successful refractive surgery.
• Understanding the consistency of manifest refraction is essential for patient outcomes.

Purpose of the Study:

• To assess the intraexaminer repeatability and interobserver reproducibility of manifest refraction.
• To determine the reliability of refractive measurements in a clinical setting.

Main Methods:

• Retrospective study at a tertiary referral center.
• Analysis of manifest refractions from 1000 eyes of patients undergoing refractive surgery.
• Standardized protocol using automated phoropter, wavefront, tomography, and topography.

Main Results:

• Mean pairwise absolute difference in spherical equivalent was 0.16 ± 0.19 diopters.
• 95% limits of agreement were within 0.50 D for sphere, cylinder, and spherical equivalent.
• Astigmatism axis reproducibility was approximately 10 degrees (SD), with 95% LoA within 22 degrees.

Conclusions:

• Manifest refraction demonstrated high repeatability and reproducibility, with a mean difference of 0.16 D.
• No significant differences were found between repeatability and reproducibility for key refractive parameters.
• Preoperative multiple refractions may enhance surgical predictability and decrease enhancement rates.