Higher-order wavefront aberration and letter-contrast sensitivity in keratoconus

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Keratoconus is a progressive corneal disease characterized by irregular astigmatism and visual distortion.
• Ocular higher-order aberrations (HOAs) contribute to reduced visual quality in various eye conditions.
• Contrast sensitivity function (CSF) is a crucial measure of visual performance, often impaired in corneal diseases.

Purpose of the Study:

• To investigate the relationship between ocular higher-order aberrations and contrast sensitivity function in individuals with keratoconus.
• To compare these relationships in keratoconus patients versus healthy controls.

Main Methods:

• Ocular higher-order aberrations (HOAs) were measured using a Hartmann-Shack aberrometer in 22 eyes with keratoconus and 26 control eyes.
• Third- and fourth-order Zernike coefficients (root mean square) quantified HOAs.
• Letter-contrast sensitivity was assessed using the CSV-1000LV chart.

Main Results:

• In keratoconus eyes, contrast sensitivity significantly correlated with third-order (r=-0.736, P<0.001) and fourth-order aberrations (r=-0.464, P<0.05).
• No significant correlations were found between HOAs and contrast sensitivity in the control group.
• Borderline correlations were observed between best spectacle-corrected visual acuity (BSCVA) and HOAs in the keratoconus group.

Conclusions:

• Ocular higher-order aberrations are significantly associated with impaired contrast sensitivity in eyes affected by keratoconus.
• These findings highlight the role of HOAs in visual dysfunction in keratoconus patients.