Prediction of the small aperture intraocular lens on visual acuity in patients with keratoconus

Roberta M van den Berg; Arthur van den Berg; Karolinne Maia Rocha; Marcela Fetrin de Barros; Maya Dodhia; Michel Shahid; Stephen D Klyce

doi:10.1097/j.jcrs.0000000000001480

Prediction of the small aperture intraocular lens on visual acuity in patients with keratoconus

J Cataract Refract Surg. 2024 May 10. doi: 10.1097/j.jcrs.0000000000001480. Online ahead of print.

Authors

Roberta M van den Berg^{1

2}, Arthur van den Berg^{1

2}, Karolinne Maia Rocha¹, Marcela Fetrin de Barros¹, Maya Dodhia¹, Michel Shahid³, Stephen D Klyce⁴

Affiliations

¹ Storm Eye Institute - Medical University of South Carolina, Charleston, SC.
² Federal University of São Paulo, São Paulo, Brazil.
³ University of South Carolina School of Medicine Columbia, Columbia, SC.
⁴ Icahn School of Medicine at Mount Sinai, New York, NY.

PMID: 38742939
DOI: 10.1097/j.jcrs.0000000000001480

Abstract

Purpose: To investigate the impact of corneal higher-order aberrations (HOAs) on predicted corrected distance visual acuity (CDVA) in patients with keratoconus at varying simulated pupil apertures.

Setting: Ophthalmology clinics, Medical University of South Carolina, USA.

Design: Retrospective chart review study.

Methods: 56 eyes with keratoconus were examined using Scheimpflug tomography during routine examinations prior to medical intervention. The severity of keratoconus was graded using the Amsler-Krumeich classification. Zernike analysis was used to obtain corneal aberrations using simulated pupil diameters of 6-, 4-, and 2 mm. These data were extrapolated to obtain the total RMS HOAs for a 1.6 mm simulated pupil to evaluate the potential effect of a small aperture intraocular lens. Correlation analysis was used to study the impact and relative contributions of HOAs on CDVA. Convolution of HOAs from OPD-Scan III (NIDEK) provided a clinical method to predict CDVA with different simulated pupil sizes in corneas with irregular astigmatism.

Results: There were statistically significant positive correlations between photopic CDVA and the magnitude of total and individual (coma, spherical aberration and trefoil) HOAs in this cohort of keratoconus subjects. A keratoconus case with the small aperture IOL confirms the improvement in vision due to the pinhole effect.

Conclusions: The small aperture IOL is expected to markedly reduce aberrations in keratoconus patients up to Amsler-Krumeich class 4 severity to levels consistent with the levels seen in healthy patients. Convolution of corneal HO aberrations with the ETDRS chart provides a useful simulation of the impact of pinhole optics in aberrated eyes.