Contact Lens Update

Sarah Guthrie is a senior research associate at the Centre for Ocular Research & Education (CORE), in the School of Optometry & Vision Science at the University of Waterloo, Canada.

Presented at BCLA 2021, this conference highlight is adapted from an abstract by Guthrie et al. and explores the link between vision and comfort in multifocal contact lens wear. Study participants wore two different multifocal lens designs and while both lenses performed well, lens preference based on overall comfort was significantly correlated with lens preference based on vision at certain distances. This included near, for digital device use and overall vision.

These findings complement several points reviewed in the CLEAR papers. First, that assessing and predicting the visual performance of complex optical designs such as multifocals based on baseline clinical objective measures and standard visual acuity tests has been suggested to be inadequate. It is recommended that vision is assessed using real-world tasks and, ideally, with an extended trial to allow for visual adaptation. Second, that there is a correlation between the comfort and vision performance of a contact lens, a result that has been reported elsewhere for induced blur,² and wearers of toric lenses.³ This new study provides further evidence of that link, and serves as a good reminder for the clinician to ensure both vision and comfort are optimized in their contact lens wearers to help achieve the best performing overall wear experience for their patients and prevent dropout.

Adapted abstract:

TITLE: Comfort and vision correlations in daily disposable multifocal lenses

AUTHORS: Sarah Guthrie, Doerte Luensmann, Jill Woods, Jose Vega, Gary Orsborn

PURPOSE:

To evaluate subjective responses to two daily disposable multifocal contact lenses (MFCLs), lens A and lens B, and to see if there is a correlation between lens preference based on vision and comfort.

METHODS:

Habitual MFCL wearers participated in a prospective, randomized, subject-masked, bilateral crossover study at five sites. Subjects wore the study MFCLs for 2-weeks each and then responded to preference questions comparing the study lenses for comfort and vision for near, intermediate, distance, digital device use and overall at all distances. A 5-point Likert scale (Strong/slight preference for each lens or no preference) was used.

RESULTS:

For the 58 eligible subjects (50F:8M; mean 54.4±7.3 years), preferences are reported as follows lens A:lens B, p-value): subjects favoured lens A for overall comfort (26:9, p=0.03), intermediate vision (25:8, p=0.03), overall vision (34:10, p=0.04) and vision for digital device use (27:10, p=0.03). Preferences were equivocal for near vision (29:14, p=0.06) and distance vision (13:19, p=0.51).

Correlation analysis found that the lens preference based on overall comfort was significantly correlated (all p<0.05) with lens preference based on vision at near (r_s=0.61), intermediate (r_s=0.48), overall (r_s=0.65) and for digital device use (r_s=0.66).

Lens preference based on overall vision was also correlated with lens preference based on vision at near (r_s=0.85), intermediate (r_s=0.71), and for digital device use (r_s=0.87). Lens preference based on vision with digital device use correlated with lens preference based on vision at near (r_s=0.85), and intermediate distance (r_s=0.69).

CONCLUSIONS:

Preferences for overall comfort and overall vision were both significantly correlated to the same three preferences of near, intermediate and digital device vision, illustrating how comfort and vision are intricately related when evaluating MFCLs and supporting how poor vision could potentially impact comfort.

REFERENCES:

1. Wolffsohn JS, Dumbleton K, Huntjens B, et al. CLEAR – Evidence-based contact lens practice. Cont Lens Anterior Eye 2021;44:368-97.
2. Rao SB, Simpson TL. Influence of Vision on Ocular Comfort Ratings. Optom Vis Sci 2016;93:793-800.
3. Orsborn G, Vega J, Orsborn G. Correlation Between Ocular Comfort and Vision Quality of Three Daily Disposable Soft Toric Contact Lenses with Different Moduli of Elasticity. Cont Lens Anterior Eye 2019;42:e12.