Chromatic aberration of phakic and pseudophakic eyes measured in the clinic

Session Details

Session Title: Presented Poster Session: After Surgery

Venue: Poster Village: Pod 1

First Author: : M.Millan SPAIN

Co Author(s): :    N. Garzon   F. Vega                    

Abstract Details

Purpose:

We present a psychophysical method and a simple setup for the clinical assessment of the longitudinal chromatic aberration (LCA) in phakic and pseudophakic eyes. A proof of concept built from inexpensive and non-sophisticated opto-mechanical components was used to obtain the preliminary clinical results presented in this work.

Setting:

'- Universitat Politècnica de Catalunya, Barcelona tech. Barcelona, Spain. - IOA Madrid, Innova Ocular. Madrid, Spain.

Methods:

We used an autorefractor combined with a Scheiner disc and sequentially illuminated with red and blue lights to determine the chromatic difference of refraction (CDRx) as an estimate of LCA. This simple method applies to unaccommodated eyes, such as in pseudophakic patients or in phakics under mydriasis, even in the presence of positive or negative refractive errors and astigmatism. We considered a control group of phakic patients and three groups of pseudophakic patients with monofocal implants of different designs and materials (Tecnis-1 ZCB00 and Sensar-1 AAB00, both from Johnson & Johnson Vision, Inc., and Acrysof SN60WF from Alcon Laboratories, Inc.).

Results:

The CDRx obtained for the groups of phakic eyes were 1.3±0.42 D, generally higher than those obtained for the pseudophakics, in good agreement with previous results obtained with experimental setups that cannot be easily implemented in clinics. However, such differences were found statistically significant (p-value < 0.05) only in patients implanted with Tecnis-1 ZCB00 and Sensar-1. Within the pseudophakic groups, the CDRx values varied from SN60WF (0.96±0.34 D) to Tecnics-1 (0.69±0.21 D) and Sensar-1 (0.64±0.17 D) groups, with statistical significance between SN60WF and Sensar-1. This result is consistent with the dispersive characteristics (Abbe number) of the lens materials.

Conclusions:

The proposed method, based on an autorefractor and the Scheiner principle, and the setup (proof of concept) were successfully introduced in the clinics to assess LCA. The results obtained for phakic and pseudophakic eyes implanted with monofocal lenses are satisfactory and consistent with those reported by other researchers in related papers. This fact stimulates to refine the optomechanics of the setup to improve its precision and patient-friendly driving. The method is robust to the presence of spherical error and astigmatism.

Financial Disclosure:

None