Purchase this article with an account.
Y. Niu, R. Applegate, J. Marsack; Dynamic Simulation of the Effect of Toric Soft Contact Lens Movement on Retinal Image Quality. Invest. Ophthalmol. Vis. Sci. 2007;48(13):5399.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To develop a technology designed to dynamically simulate the effect of toric soft contact lens movement on the retinal image quality.
To develop the technology a soft toric contact lens wearing subject with -6.50-1.75X10°, -8.00-1.75X180° in the right and left eye was cyclopleged and dilated with 1% cyclopentolate and 2.5% phenylephrine. Wavefront aberrations over a 5mm pupil with contact lenses were measured at 30 Hz for 40 seconds (1200 measurements) using COAS aberrometer. Each of the 1200 wavefront error measurements was input into Visual Optics Laboratory (version 7.15) to generate a retinal simulation of a high contrast logMAR visual acuity chart. Each simulation was imported into a MatLab psychotoolbox program to generate a movie. Three different simulation movies with different randomized letters were made for each eye. Visual acuity and chart reading time were measured three times while the subject read unaberrated charts with contact lenses through a 5mm artificial pupil and while reading the simulated movies with best cycloplegic spectacle correction through a 3mm artificial pupil to minimize the eyes’ residual aberrations.
Qualitatively, the subject reported that the simulations although of lower contrast reasonably reflected the dynamic nature of vision while wearing toric soft lenses. Quantitative measurements revealed for the right eye there was an 8 letter decrease in visual acuity while reading the simulated chart. For the left eye there was a 15 letter difference. In both cases the simulation was read slower, 15 and 38 seconds right eye and left eyes.
Qualitatively the movies illustrate the variations in retinal image quality that occur during the wear of a toric contact lens. Quantitatively the simulations need to better reflect actual retinal image quality. Improvements can be made by: 1) pre-emphasizing the simulation; and 2) measuring the aberrations while wearing the toric lens at the same time as the acuity measurements. This new technology visually demonstrates how contact lens movement dynamically influences retinal image quality for both the patient and prescribing clinician and provides visual evidence of the need to better stabilize toric corrections and future wavefront guided corrections.
This PDF is available to Subscribers Only