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Understanding real-time diurnal contact lens comfort

Contact lenses
Dr Andrew Pucker discusses changes that occur to contact lens comfort over the course of a day

Worldwide contact lens (CL) market growth has been essentially stagnant over the past several years because the number of new CL wearers is roughly equal to the number of patients who have dropped out of CLs.1,2 While CL dropout can be attributed to factors such as poor vision, high cost or inconvenience,3 CL discomfort is easily the top reason why established soft CL wearers drop out.1

CL comfort has historically been evaluated in the test room via self-report or in clinical studies with take-home diaries, though each of these approaches potentially suffer from intentional or unintentional patient reporting biases. Nevertheless, modern technologies have allowed investigators over the past decade or so to capture real-time comfort data with smartphone technologies to help avoid this issue.4-7

This information is important not only to better help clinicians and patients understand the performance of a typical CL, but it can aid in developing strategies for circumventing CL dropout. Thus, the goal of this article is to highlight the literature on this topic, so practitioners are fully informed and can appropriately educate their patients.

 

Literature Review

Santodomingo et al (n=80 subjects) were among the first to analyse real-time CL comfort with smartphone technology in 2010.7 The authors specifically evaluated non-CL wearers and hydrogel, silicone-hydrogel, and hard CL wearers by sending them text messages in the morning, afternoon and night.

The text messages contained a 0-100 comfort scale (0 = pain that cannot be tolerated). Santodomingo et al determined that the mean comfort reduction of hydrogel (-4.5 ±11.8, -8.3 ±14.1) and silicone-hydrogel (-4.5 ±9.6, -9.1 ±8.7) CLs was worse in the afternoon and night compared to the morning, and these comfort reductions were greater than those experienced by hard CL wearers (-1.0 ±11.3, -7.3 ±9.7) and non-CL wearers (-1.8 ±16.3, -4.1 ±21.9) at the same time points.

 

Figure 1: Comfort reduction (using a scale of 0-100) based on data by Santodomingo et al 2010

Fogt and Patton (2022) later compared a pair of studies evaluating the real-time comfort of daily disposable CL wearers.4,5 The authors’ first study (n=35) specifically refitted their subjects into Precision1 Contact Lenses, and they sent the subjects a forced-choice 1 to 10 grading scale (1 = poor comfort), which was to be completed at 10, 12, 14 and 16 hours of CL wear over the course of five weekdays.

They also evaluated initial CL comfort with a 0 to 100 visual analog scale (VAS; 0 = poor comfort) at the time of fitting. With these scales, the authors found the median (interquartile range) initial comfort was 98.0 (16.0) and the median comfort at 10, 12, 14 and 16 hours of wear over the course of the study was 9.0 (1.2), 8.6 (1.4), 8.0 (1.4) and 7.4 (1.7), respectively.

Fogt and Patton (n=30 subjects) repeated their study with a similar methodology in astigmatic subjects who were refit into Precision1 for Astigmatism CLs, and the authors found that the median initial comfort of these CL was 100.0 (9.0), and the median comfort in astigmatic CL wearers to be 10 (1), 9 (2), 9 (2) and 8 (2) at 10, 12, 14 and 16 hours of wear over the course of the study, respectively.

 

Call et al (48 = subjects) later recruited asymptomatic, spherical CL wearers and refit them in Total30 Monthly CLs (6). The authors sent the subjects a ± 50 VAS (0 = neutral, -50 = poor comfort, +50 = good comfort) at the initial fitting. They then sent the same type of text message to the subjects to evaluate comfort in the morning and at 10, 12, 14, and 16 hours of wear on days one to five and at two weeks and one month.

The authors determined that the initial CL comfort at the time of CL fitting was 45.56 ± 9.20, and they found that the mean comfort of these CL on the first morning of wear was 42.91± 13.79. Call et al also determined that CL comfort decreased by 6.25 units over the course of the first day and by 12.42 units at the end of the day between the one-day and one-month time points.

Comfort furthermore appeared to immediately improve each day directly after CL removal (range = 5.97 to 11.42 units). While these decreases in comfort over the day each day and over the course of the study were significant, subjects reported good comfort (positive scores) for the duration of the study. This determination of good comfort at all time points was made possible by Call et al’s innovative VAS instrument, which is a claim that cannot be easily discerned in similar studies.

 

Conclusions

It has been long-established that CL comfort deteriorates over the course of the day.8 This decrease in ocular comfort occurs in non-CLs wearers as well, but it is more pronounced in CL wearers.8 It is also know that decreases in CL comfort are much more pronounced in symptomatic than asymptomatic CL wearers.9 Recent data noted above suggests that the comfort of modern CL also deteriorates over the course of the day; however, it may not worsen to the point that ‘normal’ patients become uncomfortable.

This point comes with the caveat that the above studies typically only included patients who began the studies as comfortable wearers, and because of this more research is needed to map the real-time comfort of patients who are struggling with CL discomfort. Nevertheless, these data do give hope that recent innovations in CL materials and wear schedule will help make
life better for the millions of patients who struggle with CL discomfort. 

  • Dr Andrew Pucker is senior director of clinical and medical science with Lexitas Pharma Services. He holds an undergraduate degree in cellular and molecular biology. Following which he earned his optometry degree, Masters and PhD.

 

Disclosures

Dr Pucker has received research support from Alcon Research, LLC and Art Optical. Dr Pucker has served as a consultant for Alcon Research, LLC, Euclid Systems, and Hanall Biopharma.
Dr Pucker is currently an employee of Lexitas Pharma Services, which is a company that does not sell or market drugs or devices; Lexitas Pharma Services only performs research for hire.

 

References

  1. Pucker AD, Tichenor AA. A Review of Contact Lens Dropout. Clin Optom (Auckl). 2020;12:85-94.
  2. Markoulli M, Kolanu S. Contact lens wear and dry eyes:
    challenges and solutions. Clin Optom (Auckl). 2017;9:41-8.
  3. Young G, Veys J, Pritchard N, Coleman S. A multi-centre study of lapsed contact lens wearers. Ophthalmic Physiol Opt. 2002;22(6):516-27.
  4. Fogt JS, Patton K. Evaluation of Wear Experience with Soft Daily Disposable Lenses for Astigmatism over 16 Hours of Wear. Clin Optom (Auckl). 2022;14:207-14.
  5. Fogt JS, Patton K. Long Day Wear Experience with Water Surface Daily Disposable Contact Lenses. Clin Optom (Auckl). 2022;14:93-9.
  6. Call T, Pucker AD, McGwin G, Jr., Franklin QX, Logan A. Real-Time Ocular Comfort Reporting in Monthly Replacement Contact Lens Wearers. Clin Optom (Auckl). 2023;15:97-103.
  7. Santodomingo-Rubido J, Barrado-Navascues E, Rubido-Crespo MJ. Ocular surface comfort during the day assessed by instant reporting in different types of contact and non-contact lens wearers. Eye Contact Lens. 2010;36(2):96-100.
  8. Dumbleton KA, Guillon M, Theodoratos P, Patel T. Diurnal Variation in Comfort in Contact Lens and Non-contact Lens Wearers. Optom Vis Sci. 2016;93(8):820-7.
  9. Woods CA, Bentley SA, Fonn D. Temporal changes in contact lens comfort over a day of wear. Ophthalmic Physiol Opt. 2016;36(6):643-8.