Refractive Changes Induced by Spherical Aberration in Laser Correction Procedures: An Adaptive Optics Study.

Area of Science:

• Ophthalmology
• Optics
• Vision Science

Background:

• Spherical aberration is a key optical parameter influencing visual quality.
• Understanding its impact is crucial for optimizing laser vision correction outcomes.

Purpose of the Study:

• To investigate the effects of induced positive and negative spherical aberration on vision.
• To determine the relationship between spherical aberration and visual performance within the scope of laser vision correction.

Main Methods:

• Spherical aberration was systematically induced in 10 eyes using an adaptive optics system.
• Measurements included visual acuity, depth of focus, contrast sensitivity, and refractive changes with varying pupil sizes.
• Natural aberrations, astigmatism, and spherical refraction were controlled or corrected.

Main Results:

• Induced spherical aberration correlated with refractive changes (1.60 D/µm), causing myopia with positive aberration and hyperopia with negative aberration.
• Contrast sensitivity significantly worsened with increasing spherical aberration (R² = 59%).
• Pupil constriction led to refractive shifts, potentially impacting near vision.

Conclusions:

• An inverse linear relationship exists between refractive state and induced spherical aberration.
• Small spherical aberration values do not degrade visual acuity or depth of focus.
• Positive spherical aberration may induce night myopia and negatively affect near vision with pupil constriction.