Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction?

Area of Science:

• Ophthalmology and Optometry
• Visual Optics
• Optical Engineering

Background:

• Accurate refractive correction is crucial for optimal visual performance.
• Traditional subjective refraction can be time-consuming and influenced by patient responses.
• Objective refraction methods aim to provide faster and potentially more consistent results.

Purpose of the Study:

• To evaluate if visual Strehl (VSX) optimization of objective refraction matches or exceeds subjective refraction in visual performance.
• To determine patient preference between VSX-optimized objective refraction and subjective refraction in free viewing conditions.

Main Methods:

• Wavefront aberrations and subjective refractions were measured in 40 visually normal eyes.
• Objective refractions were determined by optimizing the visual Strehl (VSX) metric for measured wavefront errors.
• High and low contrast visual acuity (VA) and free viewing preferences were compared between objective and subjective refractions.

Main Results:

• VSX-optimized objective refraction provided clinically equivalent high and low contrast visual acuity compared to subjective refraction in myopic eyes.
• In free viewing, 72% of myopic eyes preferred the VSX-objective refraction over the subjective refraction when undilated.
• For undercorrected hyperopic eyes, subjective refraction yielded better visual acuity than VSX-objective refraction.

Conclusions:

• A method for simultaneous objective optimization of sphere, cylinder, and axis using VSX from wavefront data is presented.
• VSX-optimized objective refraction offers equivalent visual performance to subjective refraction in myopic individuals and is often preferred.
• Subjective refraction remains superior for habitually undercorrected hyperopic eyes.