Wavefront aberrations in aging measured with Hartmann-Shack at 3- and 5-mm pupil sizes

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Visual acuity (VA) measurements can be confounded by optical aberrations, especially in aging eyes.
• These aberrations can lead to inaccurate assessments of retinal health and increased measurement variability.
• A 3-mm pupil approximates the theoretical optical size for optimal VA.

Purpose of the Study:

• To quantify and compare wavefront aberrations for 3-mm and 5-mm pupils.
• To assess the impact of pupil size on VA measurements intended for retinal health evaluation.
• To investigate the influence of age on wavefront aberrations.

Main Methods:

• Wavefront aberrations were measured in 39 normally sighted adults using a 3-mm and 5-mm pupil setting.
• Measurements were taken without pupil dilation using a Pentacam AXL WAV instrument.
• Zernike terms (orders 1-6) were computed, and test-retest variability was analyzed.

Main Results:

• A 3-mm pupil resulted in significantly reduced average wavefront aberrations compared to a 5-mm pupil (21 of 26 Zernike values, p<0.05).
• The 3-mm pupil exhibited significantly less variability in Zernike values across all aberrations (F=54.625, p<0.001).
• Age-related changes in aberrations were noted for vertical astigmatism, horizontal coma, spherical aberration, and vertical quadrafoil, with increased against-the-rule astigmatism in older adults.

Conclusions:

• Utilizing a 3-mm pupil for VA measurements can minimize the influence of anterior segment optical factors on retinal health assessments.
• Reduced wavefront aberrations and variability with a 3-mm pupil enhance the reliability of VA measurements.
• Age-related changes in astigmatism, particularly the increase in against-the-rule astigmatism, should be considered in visual assessments.