Abstract
Purpose :
To develop functional visual tests to better understand the potential advantages of a full sphero-cylindrical toric correction for contact lenses (CL) neophytes with low values of astigmatism.
Methods :
We used a custom set of video cameras and thin film pressure sensors to monitor and automatically quantified several daily functional activities in terms of time and performance. These activities include i) pouring a liquid into a recipient up to a certain marked level, ii) inserting a key in a lock and turning it, and iii) finding three (digital) files in a computer desktop placed among other files and attach them into an email. Currently, we have tested the procedures in nineteen first year university students. All of them were contact lens neophytes with no previous experience of CL fitting. Subjects were split into two homogenous groups matched by age and refractive error with no statistically significant differences within these variables. Subjects in group one (N=10) had a cylinder value of -0.9 ± 0.3 D and were monocularly fitted with a spherical CL (Precision1, Alcon Laboratories, Inc, Fort Worth, TX). Subjects in group two (N=9) had a similar cylinder, -1.0 ± 0.4 D, and were fitted with a toric CL (Precision1 for Astigmatism). All subjects performed three trials of tasks i) and ii) and a single email test. Data was averaged correspondingly.
Results :
On average, subjects in the toric group were able to complete all tasks faster than subjects in the spherical lens group. Pouring the liquid, opening the lock and sending the attachments by email was respectively 28%, 3% and 10% faster in the toric group compared to the spherical group. However, for this pilot study, we only reached statistically significant differences for the first task (pouring the liquid up to a certain level; p = 0.02). Interestingly, for those tests with repeated trials (pouring and key lock), subjects in the toric group performed more consistently across trials than subjects in the spherical group. On average, data dispersion was two times smaller in both tests for the toric group.
Conclusions :
Toric CL fitting tended to improve some aspects of functional vision compared to a spherical CL fitting in CL neophytes even with low levels of astigmatism. Further studies in a larger population are required to confirm these functional benefits.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.