gms | German Medical Science

Purpose: The concept of an IOL correcting the eye's longitudinal chromatic aberration (LCA) has recently been introduced, but clinical literature on the impact of this technology is scarce. This study aims to test how LCA affects the patients' visual quality and depth of focus.

Methods: Chromatic-aberration effects were studied monocularly in 37 patients implanted with a monofocal lens. LogMAR corrected distance visual acuity (CDVA) and defocus curve were assessed using a computerized vision-testing system for optotype randomization. Defocus was induced using trial lenses with the power of +1 D to -2 D (0.5 D step). Contrast sensitivity was evaluated at four spatial frequencies. Measurements were performed with the eye's natural conditions, as well as with increased and corrected (by the same amount) chromatic aberration. LCA was altered by the introduction of zero-power lenses.

Results: The mean (±standard deviation) CDVA was -0.11±0.07 for the natural condition, -0.13±0.07 for the LCA-corrected eye, and -0.06±0.08 for the eye with increased LCA. A sharp decline of the defocus tolerance was found after the LCA correction with the DCVA value of 0.38±0.15 at -1.5 D. But for the natural and increased LCA, it was 0.32±0.16 and 0.25±0.13, respectively. Contrast sensitivity was slightly improved at all spatial frequencies after the LCA correction, which was closely followed by the natural-eye performance. Increased LCA resulted in minimally reduced contrast sensitivity, mainly at higher spatial frequencies.

Conclusion: We demonstrated that neither correction nor increase of LCA yields a substantial functional effect on vision. Chromatic aberration increases the depth of focus of a pseudophakic eye.