Ocular higher-order aberrations in individuals screened for refractive surgery

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Ocular higher-order aberrations (HOAs) impact visual quality and are crucial for understanding refractive error.
• The distribution and symmetry of these aberrations, particularly spherical aberration (SA) and coma, are not fully characterized across diverse populations.
• Age-related changes in ocular aberrations require further investigation.

Purpose of the Study:

• To investigate the population distribution of ocular higher-order aberrations (HOAs) from 3rd to 6th orders.
• To evaluate the symmetry of ocular aberrations between the right and left eyes within individuals.
• To examine how ocular aberrations, including SA and coma, differ with age.

Main Methods:

• A Hartmann-Shack wavefront sensor (WaveScan system) was used to analyze HOAs in 532 eyes of 306 subjects (mean age 41 years).
• Zernike coefficients and RMS values for HOAs, SA, and coma were calculated for a 6.0 mm pupil.
• Correlation analyses assessed the relationship between aberrations and age, and between fellow eyes.

Main Results:

• The highest mean absolute values were observed for 4th-order SA, 3rd-order coma, and trefoil terms.
• Mean RMS values were 0.305 ± 0.095 µm for HOA, 0.128 ± 0.074 µm for SA, and 0.170 ± 0.089 µm for coma.
• Moderate to high correlations (P<.001) were found for HOA, SA, and coma between right and left eyes, indicating significant symmetry. Weak correlations with age were also noted.

Conclusions:

• Ocular HOAs exhibit considerable inter-subject variability and show a slight increase with advancing age.
• A notable degree of mirror symmetry for HOAs, SA, and coma exists between the fellow eyes of individuals.
• These findings contribute to a better understanding of ocular wavefront aberrations and their clinical implications.