Satisfaction with Precision1 for Astigmatism CLs

The past 25 years have seen a number of very significant developments in contact lens products and manufacturing technology. Studies have shown, that when compared with reusable lenses, daily disposable lenses offer patients convenience and improved physiological response,^1,2 while silicone hydrogel materials offer superb oxygen permeability and excellent oxygen-related physiological performance.³ Daily disposable silicone hydrogel lenses offer patients a combination of all these benefits and are now considered the contemporary ‘standard of care’.⁴

Providing patients with optimal vision correction is the goal of all eye care professionals (ECP) when prescribing spectacles and contact lenses. While patients are often categorised in terms of their spherical refractive error, it is paramount not to neglect the toric component of their visual correction. Astigmatism is the most prevalent refractive error in the adult population⁵ with nearly 50% of spectacle wearers having astigmatism of 0.75DC or more in at least one eye and around a third of potential contact lens wearers requiring astigmatic correction.⁶ While an ECP would be unlikely to consider excluding a small cylinder when prescribing spectacles for an astigmatic, some practitioners have the practice of using this strategy for contact lens wearers. However, when astigmatic patients are fitted with toric contact lenses, it has been shown that they experience better acuity and comfort than with spherical lenses.⁷ Previously, it was thought that fitting thick or high modulus spherical contact lenses to astigmatic patients was a method of ‘masking’ astigmatism and avoiding the use of a toric contact lens, but this theory has subsequently been disproved.⁸

The contemporary gold standard contact lens for astigmatic patients is, therefore, silicone hydrogel daily disposable toric contact lenses. In some cases, the perceived cost of daily disposable contact lenses can be considered a barrier to selecting the modality,⁴ which is a particular problem for those who require toric lenses, which tend to be more expensive.⁹ However, over two thirds of CL wearers want their ECP to recommend the optimum product for them, irrespective of cost.¹⁰

Contact lens dropout, where patients discontinue wear, is a problem for all ECPs. Ensuring a positive contact lens wearing experience is a major contributor in improving retention. Contact lens discomfort and poor vision are both common reasons for patients discontinuing wear.^11,12 In toric contact lens wearers, there is a link between contact lens comfort and vision.¹³ It is, therefore, not surprising that retention rates for patients using toric lenses are lower than for spherical lenses.^14,15

There is, therefore, a clear need to be able to offer astigmatic patients toric contact lenses that combine excellent comfort, stability, visual acuity, physiological response, convenience and affordability.

Precision1

Precision1 for Astigmatism are daily disposable toric water surface contact lenses manufactured by Alcon. They use Smartsurface technology to provide a permanent 2 to 3μm layer of moisture on the surface. The water content increases from 51% at the core to over 80% at the outer surface, as shown in figure 1. The lubricious outer layer is designed for comfort and to support the tear film. The lenses, which are manufactured from verofilcon A, have been shown in in vitro laboratory experiments to cause lower levels of cell damage than lenses that do not have Smartsurface technology.¹⁶ It is thought the high water content surface reduces friction between the lens and the cornea and lowers cellular damage.

Precision1 are some of the most oxygen transmissible (Dk/t) lenses available¹⁷ and provide nearly three times the amount of oxygen required by the cornea for daily contact lens wear.¹⁸ The lenses provide excellent acuity, comfort, handling,¹⁹ fitting²⁰ and wettability.²¹ Precision1 for Astigmatism use the 8|4design for stabilisation (see figure 2), which uses two thickened stability points at four and eight o’clock, which interact with the eyelids on blinking. The technique gives predictable, consistent and stable orientation.²²

Precision1 for Astigmatism combines all of these features in a daily disposable toric format that provides excellent comfort, acuity, handling and fitting in an affordable contact lens. The availability of lenses with such a range of features is a major contribution in reducing dropout of contact lens wearers.

Wearer Experience

In order to establish real-world performance of Precision1 for Astigmatism, 245 existing toric contact lens wearers were re-fitted with Precision1 for Astigmatism and asked to compare their experience to their previous lenses by completing a survey before and after the trial period.

Precision1 for Astigmatism showed increased wearing time and comfort compared to participants’ original contact lenses. Wearing time was increased to 11 hours per day on 6.1 days per week from 10.4 hours per day on 4.8 days per week with wearers’ own lenses. Participants reported that the comfort was improved and that Precision1 for Astigmatism lenses could be worn comfortably for an average of 9.7 hours per day, compared to 8.1 hours with their habitual lenses.²³

Contact lens comfort

Wearers stated that, of their wearing time, Precision1 for Astigmatism could be worn comfortably for 88% of the time, compared to 78% with their own contact lenses. When participants were asked about their own contact lenses, 34% agreed or strongly agreed with the statement, ‘My lenses felt as comfortable at the end of the day yesterday as they did when I first put them in.’ Whereas, for Precision1 for Astigmatism, 87% either agreed or strongly agreed with the statement, ‘I feel comfortable from the time I put the lenses on until I want to take them out,’ which shows that they can give much improved comfort, particularly towards the end of the day.

Figure 3: Summary of participants’ responses regarding comfort of Precision1 for Astigmatism²³

Figure 3 gives a summary of participant responses regarding their wearing experience with Precision1 for Astigmatism. When asked if their lenses felt moist until the end of the day, 76% of wearers either agreed or strongly agreed. This result fits with the finding that fewer patients used rewetting drops when wearing Precision1 for Astigmatism compared to their own lenses (25% versus 18%). More than eight in 10 participants felt that Precision1 for Astigmatism allowed them to feel comfortable when looking at their mobile phone or computer screen for an extended period of time.²³

Contact lens handling

Participants gave very positive responses regarding Precision1 for Astigmatism when asked about lens handing, as shown in figure 4. A response of agree or strongly agree was given by 94% of wearers to the statement, ‘It was easy to place the lenses on my eyes.’ The lenses were considered to be easy to handle by 86% of patients.²³

Figure 4: Summary of participants’ responses regarding handling Precision1 for Astigmatism²³

Vision

Participants were asked questions regarding their real-life experience with the contact lenses. Nine out of 10 respondents agreed or strongly agreed with the statement, ‘The lenses provide clear distance vision while I am engaging in activities such as driving, biking, watching TV’. Over 80% found that the lenses provided clear vision while they were looking at digital devices such as their mobile phone or computer screen (see figure 5). The data show that wearers find the vision with Precision1 for Astigmatism to be appropriate for contemporary activities.²³

Figure 5: Summary of participants’ responses regarding their vision with Precision1 for Astigmatism²³

Lifestyle

Figure 6 summarises responses to questions regarding lifestyle and shows that wearers were able to get on with their busy lives without worrying about their contact lenses. When asked if their contact lenses supported their active lifestyle, nine out of 10 participants either agreed or strongly agreed with the statement. Over 80% gave a positive response to, ‘I did not have to think about my contact lenses today,’ and 89% to, ‘The lenses allowed me to focus on the moments that matter, not my lenses’.²³

ECP Experience

Of the 50 ECPs who fitted their patients with Precision1 for Astigmatism, 95% said that the lenses were easy to fit, with more than nine out of 10 either agreeing or strongly agreeing with the statement, ‘The lenses are as easy to fit as spherical lenses’. Nearly all ECPs (98%) trust the performance of the lenses for their astigmatic patients with long days and on-the-go lifestyles and 88% agreed or strongly agreed that the contact lenses drove high patient satisfaction, as shown in figure 7. After participating in the study, 85% of ECPs agreed that Precision 1 for Astigmatism would become their new ‘go to’ toric lens of choice for patients with on-the-go lifestyles and 94% either agreed or strongly agreed with the statement, ‘I would recommend the lenses to my colleagues for their astigmatic patients that need long lasting vision and comfort for their busy lifestyles’; 82% considered that Precision1 for Astigmatism may motivate their patients to return for annual renewal.²³

Figure 7: Summary of ECP experience on fitting Precision1 for Astigmatism²³

Summary

Daily disposable silicone hydrogel contact lenses are the contemporary standard of care. Precision1 for Astigmatism is a daily disposable toric silicone hydrogel lens that has excellent comfort, acuity, oxygen permeability and physiological response. They provide improved wearing time and comfort compared to patients’ own contact lenses with nine out of 10 wearers agreeing they could wear the contact lenses all day long and that the lenses support their active lifestyles.²³

Nearly all ECPs (98%) agree that they trust the performance of Precision1 for Astigmatism for their astigmatic patients with long days and on-the-go lifestyles and 88% consider that the lenses drive high patient satisfaction.²³

In general, the rate of patients discontinuing contact lens wear is higher for those wearing toric than spherical contact lenses.¹⁵ The excellent comfort, handling, acuity and wearing time of Precision1 for Astigmatism means they are an affordable contact lens that ECPs can choose for their astigmatic patients which are designed to enhance outcomes and improve patient retention.²³

• Dr Inma Perez-Gomez is head of professional affairs for Europe, Middle East and Africa at Alcon Vision Care, Roberto Valente is a Professional Affairs Specialist at Alcon and Harald Vonbun is a Professional Affairs Manager for Alcon

References

1. Chalmers RL, Keay L, McNally J, Kern J. Multicenter case-control study of the role of lens materials and care products on the development of corneal infiltrates. Optometry and Vision Science. 2012;89(3):316-25.
2. Diec J, Papas E, Naduvilath T, Xu P, Holden BA, Lazon de la Jara P. Combined effect of comfort and adverse events on contact lens performance. Optometry and Vision Science. 2013;90(7):674-81.
3. Efron N, Morgan PB, Cameron ID, Brennan NA, Goodwin M. Oxygen Permeability and Water Content of Silicone Hydrogel Contact Lens Materials. Optometry and Vision Science. 2007;84(4):328-37.
4. Orsborn G, Dumbleton K. Eye care professionals’ perceptions of the benefits of daily disposable silicone hydrogel contact lenses. Contact Lens and Anterior Eye. 2019;42(4):373-9.
5. Sanfilippo PG, Yazar S, Kearns L, Sherwin JC, Hewitt AW, Mackey DA. Distribution of astigmatism as a function of age in an Australian population. Acta Ophthalmologica. 2015;93(5):e377-e85.
6. Young G, Sulley A, Hunt C. Prevalence of astigmatism in relation to soft contact lens fitting. Eye & Contact Lens. 2011;37(1):20-5.
7. Chaudhry M, Sah SP, Sharma IP, Mondal S. Does offering only the spherical contact lens trial to the low astigmats mislead the practitioners? International Journal of Ophthalmology. 2021;14(8):1281-4.
8. Edmondson L, Edmondson W, Price R. Masking astigmatism Ciba Focus Night & Day vs Focus Monthly. Optometry and Vision Science. 2003;80 (Supp):184.
9. Efron SE, Efron N, Morgan PB, Morgan SL. A theoretical model for comparing UK costs of contact lens replacement modalities. Contact Lens and Anterior Eye. 2012;35(1):28-34.
10. CooperVision. CooperVision Studies Reveal Gap Between ECP and Consumer Expectations for 1-Day Silicone Hydrogel Contact Lens Recommendations. 2018. Available from: https://coopervision.com/our-company/news-center/p... -consumer. Accessed 14 October 2021.
11. Pucker AD, Tichenor AA. A Review of Contact Lens Dropout. Clinical Optometry. 2020;12:85-94.
12. Read ML, Navascues-Cornago M, Keir N, Maldonado-Codina C, Morgan PB. Monitoring ocular discomfort using a wrist-mounted electronic logger. Contact Lens and Anterior Eye. 2020;43(5):476-83.
13. Maldonado-Codina C, Navascues Cornago M, Read ML, et al. The association of comfort and vision in soft toric contact lens wear. Contact Lens and Anterior Eye. 2021;44(4):101387.
14. Sulley A, Young G, Hunt C. Factors in the success of new contact lens wearers. Contact Lens and Anterior Eye. 2017;40(1):15-24.
15. Sulley A, Young G, Hunt C, McCready S, Targett MT, Craven R. Retention Rates in New Contact Lens Wearers. Eye & Contact Lens. 2018;44 Suppl 1:S273-S82.
16. Hart SM, McGhee EO, Urueña JM, et al. Surface Gel Layers Reduce Shear Stress and Damage of Corneal Epithelial Cells. Tribology Letters. 2020;68(4):106.
17. Grant T, Tang A. A Survey of Contact Lens Wearers and Eye Care Professionals on Satisfaction with a New Smart-Surface Silicone Hydrogel Daily Disposable Contact Lens. Clin Optom (Auckl). 2020;12:9-15.
18. Harvitt DM, Bonanno JA. Re-evaluation of the oxygen diffusion model for predicting minimum contact lens Dk/t values needed to avoid corneal anoxia. Optom Vis Sci. 1999;76(10):712-9.
19. Cummings S, Giedd B, Pearson C. Clinical performance of a novel daily disposable soft contact lens. Journal of Contact lens research & science. 2020;4(2):e23-e30.
20. Subbaraman L, Spear KG, Brobst A, Cummings S. Clinical lens fit characteristics of a new silicone hydrogel daily disposable and two commercially available daily disposable contact lenses. Contact Lens and Anterior Eye. 2021;44(1):5.
21. Subbaraman L, Tucker B, Leveillee E, Bauman E. Characterizing the surface properties of daily disposable contact lens materials. Contact Lens and Anterior Eye. 2021;44(1):4.
22. Based on lens movement, centration and rotation at initial fitting.In a study where n=78 eyes; Alcon data on file, 2020
23. Survey of Patient and ECP Satisfaction - AAOpt 2021 poster (v1.0) Inma Perez-Gomez, Roberto Valente, Harald Vonbun