A new method to analyse the effect of multifocal contact lenses on visual function

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Presbyopic contact lens (CL) fittings often result in simultaneous vision, which can reduce visual quality and wearer satisfaction due to differing retinal images.
• Managing presbyopia with contact lenses requires careful consideration of visual performance metrics.

Purpose of the Study:

• To develop a novel method for isolating the multifocality effect of various CL options for presbyopia management.
• To analyze the impact of multifocal CLs on binocular visual acuity (VA), stereopsis, and contrast sensitivity (CS).
• To determine the effect of a yellow filter (YF) on visual function in presbyopic individuals wearing CLs.

Main Methods:

• A prospective, double-masked, randomized pilot study was conducted with 20 healthy volunteers.
• Four types of multifocal CLs and monovision CLs were fitted, with participants wearing their habitual spectacles over the CLs.
• Binocular VA, stereopsis, and CS were assessed with and without a 455nm YF after 20 minutes of CL wear.

Main Results:

• Binocular VA and stereopsis significantly decreased with all tested multifocal CLs.
• Contrast sensitivity (CS) was reduced with most presbyopia-correcting CLs compared to spectacles, with exceptions for aspheric designs at 3 cycles/°.
• The use of a YF led to improved visual function, including better binocular VA with all multifocal CLs (significant with low-addition designs) and enhanced CS at most spatial frequencies.

Conclusions:

• A straightforward method is proposed to evaluate the impact of multifocal CL wear on VA, stereopsis, and CS.
• This method, which maintains habitual spectacle correction, aids in assessing short-term patient perception.
• The findings assist practitioners and patients in making informed decisions during the CL fitting process for presbyopia correction.