Visual performance in myopic patients wearing daily-disposable multifocal soft contact lenses

Abstract

The ageing population will become one of the biggest issues affecting Singapore in the near future. Ophthalmic practitioners will need to be ready to deal with an increased prevalence of glaucoma, cataract, age related maculopathy and even presbyopia. As presbyopes lose their ability to accommodate at near vision, visual aids such as progressive lenses, bifocal lenses, reading glasses, monovision contact lenses and multifocal contact lenses are prescribed to help them with reading difficulties and improve their daily lives. Interestingly, an international survey in 2011 revealed zero percent soft multifocal contact lenses was prescribed in Singapore for presbyopia correction. Although there are improvements in multifocal lens design and material, no new research being conducted to investigate the presbyopic lens fitting status in Singapore. Nonetheless, recent studies have shown an increased in multifocal contact lenses prescribing trends, perhaps reflecting not just the availability of newer multifocal contact lenses, but also improvement in practitioners’ confidence and knowledge in multifocal contact lenses. However, in spite of the available guides on choosing multifocal contact lenses, there is no comprehensive way to help the practitioner in selecting the best option for an individual. As such, an examination of the simplest way of predicting the most suitable multifocal lens for a patient will only enhance and add to the current evidence available. A survey was conducted to understand the Singaporean practitioners’ attitude towards soft multifocal lenses and its prescribing trend. In this survey, an increase in the rate of soft multifocal contact lens fitting was observed, the perception of the unavailability of an ‘ideal’ multifocal contact lens, and increased chair time in fitting soft multifocal contact lenses were identified as significant barriers. However, enablers such as the increased in practitioners’ motivation, confidence and proactiveness in fitting soft multifocal contact lenses were gathered. Additionally, this study aimed to compare the relative performance of three daily-replacement soft contact lenses for presbyopic correction in an optometric practice population in Singapore. The three daily-disposable multifocal contact lenses included in this study were 1-day Acuvue® Moist Brand Multifocal Contact Lenses for Presbyopia (Johnson & Johnson Vision Care, Jacksonville, FL), Clariti 1-day Mulitfocal (Cooper Vision, NY) and Dailies AquaComfort Plus Multifocal (Alcon, Fort worth, TX). In this crossover study design, 35 presbyopic participants with myopia were fitted in a random order with three different types of multifocal contact lens. After 1 month, visual performance was quantified by high contrast distance, intermediate and near visual acuity, defocus curve under photopic and mesopic conditions, reading speed, Near Activity Visual Questionnaire rating and Photographic questionnaire for Photic Phenomena. The results showed comparable levels of binocular distance, intermediate and near visual acuity achieved with the three different types of multifocal contact lens at 1-month follow up. However, a better distance acuity at distance under mesopic condition for AquaComfortPlus. In terms of subjective participant lens preference, nine participants (26%) preferred Moist multifocal, 16 participants (46%) preferred Clariti multifocal and 10 participants (28%) preferred AquaComfortPlus multifocal. However, lens preference was not related to demographic factors relating to age, gender, refractive error and the magnitude of reading addition or physiological characteristic such as pupil size. In terms of the performance of participants with their preferred lens when observing the defocus curve under mesopic condition, it emerged that there was an interaction between lens types and acuity at different levels of defocus. From this, it seems that lens preference may perhaps be driven by a change in visual experience that only manifested in low illumination conditions, suggesting it may be important to conduct objective measure such as visual acuity under mesopic condition when fitting modern-day multifocal contact lenses. It remains a hope for the future that new clinical tests or more diverse lens designs would be valuable to help the practitioner to improve the chances of first time success when fitting a multifocal contact lens for presbyopic correction.