More than 40 million patients wear contact lenses in the United States, which equates to a $3 billion industry. Still, contact lens wearers have been and continue to be plagued by symptoms of ocular irritation.1 These symptoms are found in both rigid and soft contact lens wearers alike. Because almost 90% of the contact lens market is soft contact lenses, much of our focus rests on the problems associated with soft contact lens discomfort.
McMonnies and Ho were pioneers in recognizing and analyzing discomfort in contact lens wear.2 Over time, we have seen a plethora of papers supporting their initial observations. We have also observed a dramatic shift in the industry’s focus from its initial concerns with keratitis and safety3–5 to those of contact lens discomfort. As stated before, numerous studies have confirmed the early observation that up to 50% of contact lens wearers experience dryness or discomfort at least occasionally.6–8 The issue has become so complex that the Tear Film and Ocular Surface Society committed an entire workshop to studying this dilemma.1,9–11 Over 80 global experts in the field came together to study the problem of contact lens discomfort and make evidence-based, consensus summaries and recommendations about this problem. Two years later, we are now at the precipice of moving the field even further and are excited to bring some of the latest developments in this special issue of Optometry and Vision Science devoted to contact lens discomfort. Here are some of the exciting topics covered in this issue.
One major problem facing the contact lens industry and regulatory bodies is the low number of patient-based, subjective outcomes that can be used in clinical trials. The Contact Lens Dry Eye Questionnaire is validated and accessible, and its wide use has undeniably helped advance discoveries in the field.12–15 Nevertheless, it is completely symptom-based and does not reflect other important issues that may cause discomfort in contact lens wearers. As Basuthkar and Rao demonstrate in this issue,16 ratings of comfort are highly influenced by blur. Dumbleton and colleagues demonstrate that contact lens wearers have greater discomfort by the end of the day.17 Rueff and colleagues also report that presbyopic patients discontinue lens wear because of discomfort and poor vision.18 Keratoconus patients present unique problems of comfort and vision and Bergmanson and colleagues demonstrate that scleral lenses are a good answer.19 Keir and colleagues evaluate the impact of masking on subjective ratings assessments of contact lenses and showed that while masking did not have a measurable impact of various 0 to 100 ratings, it did have an impact on subjective lens preference.20 Patients were more likely to express a preference for a lens type when they were able to handle it and its package. Stahl and colleagues address an important study design issue—the impact of a washout period between lens assessments.21 These researchers found no effect of washout period when patients were reporting on end-of-day discomfort. This has important implications when studying contact lens comparisons both in studies and in clinic. Lastly, Wirth and colleagues present a new patient-based survey instrument developed using the latest methods, e.g. item banking, factor analysis, item response theory, computerized adaptive testing, etc.22 The authors have developed and validated this new tool specifically for contact lens wearers—the Contact Lens User Experience (CLUE) Scale. The CLUE questionnaire analyzes four different domains (comfort, vision, handling, and packaging) to understand a contact lens wearer’s subjective experience with contact lenses. It is hoped that the CLUE questionnaire will help with the development of new contact lenses. It is also hoped that the CLUE questionnaire can help advise eye care providers on how best to address their contact lens patients’ barriers to success.
Although there is a clear need for more work to understand the patient’s contact lens experience, there is also a need for validated objective methods to assess contact lens discomfort. In particular, finding objective measures of patient comfort that correlate well with what contact lens wearers subjectively report is an open challenge. Although we believe that the pre-lens tear film is very dynamic and important to comfort and vision during contact lens wear, we do not understand much beyond that. Szczensa-Iskander and colleagues address this issue by assessing pre-lens tear film characteristics relative to the quality of the visual response.23 They develop and report on a new non-objective optical system that proved sensitive enough to detect a two-phase process of pre-lens tear film dynamics. It was shown that dewetting was related to the subjective response and a just-noticeable change in visual quality. Similar to this, Guillon and colleagues also report on the association between pre-lens tear film kinetics and subjective contact lens discomfort.24 In their work using the Tearscope, they showed that pre-lens tear film kinetics were worse in contact lens wearers with discomfort compared to those without discomfort. Gonzalez-Garcia and colleagues found no associations in any of the corneal sensory receptors or tear inflammatory mediators when comparing symptomatic and asymptomatic contact lens wearers.25 However, Situ and colleagues, using a Belmonte esthesiometer that was similar to that used by Gonzalez-Garcia, found that asymptomatic CL wearers had a higher cold detection sensitivity and greater intensity and irritation at stimulus detection than the asymptomatic wearers.26 Differences in methodology may partly explain these disparate findings. It was hypothesized in the TFOS Contact Lens Discomfort report on the ocular adnexa that subclinical lid papillae might be a cause of discomfort.27,28 Lievens and colleagues partly examined this by showing that the use of hydrogen peroxide disinfection can improve papillary changes observed in symptomatic wearers with discomfort.29 Although the role of contact lens edge shape was considered equivocal in the TFOS report on Contact Lens Discomfort,30 Tankam and colleagues provide a method for assessing edge shape, which may have a role in future research on edge shape and comfort.31 Dantam and colleagues assessed the contamination rates of contact lens cases, and although they did not assess correlations to comfort, this might be a fruitful area of future research. Masoudi and colleagues report that the concentration of prolactin-induced protein in tears is associated with contact lens discomfort, and this may lead to further research on the role of prolactin in tears and ocular sensation.32
The biocompatibility of contact lenses and their care solutions is a concern to researchers and clinicians. Several manuscripts report on a multisite, controlled clinical trial involving research teams at the University of Alabama at Birmingham, University of Houston, University of Manchester, and University of Waterloo. The goals of this large clinical trial were to examine the subjective and objective responses of contact lens wearers when wearing various silicone and hydrogel contact lenses in combination with several multipurpose contact lens care solutions and hydrogen peroxide. Berntsen and colleagues showed similar levels of comfort when using all combinations of contact lens materials and care solutions, with slight but not clinically meaningful increases in corneal staining (0.5 units) with several multipurpose solutions compared with hydrogen peroxide.33 In a related manuscript from the same study, Cox and colleagues report on lid margin characteristics in this large cohort of contact lens wearers.34 It is reported here that both mucocutaneous junction and meibomian gland expressibility have a significant impact on contact lens comfort, whereas other characteristics of the lid margin did not have an impact on comfort. From the same study cohort, Schulz and colleagues also evaluated and report on lid-wiper epitheliopathy.35 Lid-wiper epitheliopathy was shown to be present in a staggering 85% of this contact lens wearing cohort, yet was not related to contact lens comfort. This finding was, however, related to habitual lens type. In a completely independent study, Alzahrani and colleagues report on the inflammatory cell upregulation that occurs in the lid wiper area in contact lens wearers with discomfort.36 Using confocal microscopy, without histopathological confirmation, they report that Langerhans cells are upregulated in the lid wiper area of contact lens wearers with discomfort. Shigeyasu and colleagues report on the use of diquafosol, a P2Y2 purinogenic receptor agonist, for the treatment of dry eye.37 They report reductions in symptoms, improvement in tear breakup time, and ocular surface staining as the results of using diquafosol. Nichols and colleagues report that a carboxymethylcellulose and hyaluronic acid containing drop showed improvements in ocular symptoms after 90 days of use compared to control with a subsequent reduction in lid-wiper epitheliopathy.38 Lazon de la Jara and colleagues found that the demographics of contact lens wearers such as age, refractive error, and ethnicity affect contact lens discomfort ratings, indicating the importance of these variables in future clinical trials.39
The purpose of this special issue of OVS is to bring you the most current research and thought about contact lens discomfort, which is likely the single biggest problem facing all stakeholders involved in the use of contact lenses: patients, practitioners, and the contact lens industry. Here, you will find a valuable collection of clinical insights, perspectives, basic discoveries on etiological factors, and methodological assessments all focused on the topic of contact lens comfort. This body of work is a source of optimism that we can reduce or even eliminate the problem of contact lens discomfort. We know that the information in this special issue will move us toward this goal and be of great value to you and your patients.
Barbara Caffery, OD, PhD, FAAO
Toronto, Ontario, Canada
Murat Dogru, MD, PhD
Lyndon W. Jones, PhD, FCOptom, FAAO
Waterloo, Ontario, Canada
Meng C. Lin, OD, PhD, FAAO
Jason J. Nichols, OD, MPH, PhD, FAAO
Eric Papas, PhD, BSc, FAAO
Sydney, New South Wales, Australia
Andrew Pucker, OD, PhD, FAAO
Heiko Pult, OD, MSc, PhD
Mark D. P. Willcox, PhD
Sydney, New South Wales, Australia
1. Nichols JJ, Willcox MD, Bron AJ, Belmonte C, Ciolino JB, Craig JP, Dogru M, Foulks GN, Jones L, Nelson JD, Nichols KK, Purslow C, et al. The TFOS International Workshop on Contact Lens Discomfort: executive summary. Invest Ophthalmol Vis Sci 2013;54:TFOS7–13.
2. McMonnies CW, Ho A. Patient history in screening for dry eye conditions. J Am Optom Assoc 1987;58:296–301.
3. Schein OD, Poggio EC. Ulcerative keratitis in contact lens wearers. Incidence and risk factors. Cornea 1990;9(Suppl. 1):S55–8.
4. Poggio EC, Glynn RJ, Schein OD, Seddon JM, Shannon MJ, Scardino VA, Kenyon KR. The incidence of ulcerative keratitis among users of daily-wear and extended-wear soft contact lenses. N Engl J Med 1989;321:779–83.
5. Schein OD, Glynn RJ, Poggio EC, Seddon JM, Kenyon KR. The relative risk of ulcerative keratitis among users of daily-wear and extended-wear soft contact lenses. A case-control study. Microbial Keratitis Study Group. N Engl J Med 1989;321:773–8.
6. Nichols JJ, Ziegler C, Mitchell GL, Nichols KK. Self-reported dry eye disease across refractive modalities. Invest Ophthalmol Vis Sci 2005;46:1911–4.
7. Begley CG, Chalmers RL, Mitchell GL, Nichols KK, Caffery B, Simpson T, DuToit R, Portello J, Davis L. Characterization of ocular surface symptoms from optometric practices in North America. Cornea 2001;20:610–8.
8. Brennan NA, Efron N. Symptomatology of HEMA contact lens wear. Optom Vis Sci 1989;66:834–8.
9. Nichols JJ, Jones L, Nelson JD, Stapleton F, Sullivan DA, Willcox MD, members of the International Workshop on Contact Lens Discomfort. The TFOS International Workshop on Contact Lens Discomfort: introduction. Invest Ophthalmol Vis Sci 2013;54:TFOS1–6.
10. Nichols KK, Redfern RL, Jacob JT, Nelson JD, Fonn D, Forstot SL, Huang JF, Holden BA, Nichols JJ, members of the TFOS International Workshop on Contact Lens Discomfort. The TFOS International Workshop on Contact Lens Discomfort: report of the definition and classification subcommittee. Invest Ophthalmol Vis Sci 2013;54:TFOS14–9.
11. Dumbleton K, Caffery B, Dogru M, Hickson-Curran S, Kern J, Kojima T, Morgan PB, Purslow C, Robertson DM, Nelson JD, members of the TFOS International Workshop on Contact Lens Discomfort. The TFOS International Workshop on Contact Lens Discomfort: report of the subcommittee on epidemiology. Invest Ophthalmol Vis Sci 2013;54:TFOS20–36.
12. Chalmers RL, Begley CG, Moody K, Hickson-Curran SB. Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and opinion of contact lens performance. Optom Vis Sci 2012;89:1435–42.
13. Michel M, Sickenberger W, Pult H. The effectiveness of questionnaires in the determination of Contact Lens Induced Dry Eye. Ophthalmic Physiol Opt 2009;29:479–86.
14. Nichols JJ, Mitchell GL, Nichols KK. An assessment of self-reported disease classification in epidemiological studies of dry eye. Invest Ophthalmol Vis Sci 2004;45:3453–7.
15. Nichols JJ, Mitchell GL, Nichols KK, Chalmers R, Begley C. The performance of the contact lens dry eye questionnaire as a screening survey for contact lens-related dry eye. Cornea 2002;21:469–75.
16. Basuthkar Sundar Rao S, Simpson TL. Influence of vision on ocular comfort ratings. Optom Vis Sci 2016;93:793–800.
17. Dumbleton KA, Guillon M, Theodoratos P, Patel T. Diurnal variation in comfort in contact lens and non-contact lens wearers. Optom Vis Sci 2016;93:820–7.
18. Rueff EM, Varghese RJ, Brack TM, Downard DE, Bailey MD. A survey of presbyopic contact lens wearers in a university setting. Optom Vis Sci 2016;93:848–54.
19. Bergmanson JP, Walker MK, Johnson LA. Assessing scleral contact lens satisfaction in a keratoconus population. Optom Vis Sci 2016;93:855–60.
20. Keir N, Luensmann D, Woods CA, Bergenske P, Fahmy M, Fonn D. Effect of masking on subjective responses to daily disposable contact lenses. Optom Vis Sci 2016;93:828–35.
21. Stahl U, Keir NJ, Landers A, Jones LW. Effect of short recovery periods on ocular comfort during daily lens wear. Optom Vis Sci 2016;93:861–71.
22. Wirth RJ, Edwards MC, Henderson M, Henderson T, Olivares G, Houts CR. Development of the Contact Lens User Experience: CLUE scales. Optom Vis Sci 2016;93:801–8.
23. Szczesna-Iskander DH, Alonso-Caneiro D, Iskander DR. Objective measures of pre-lens tear film dynamics versus visual responses. Optom Vis Sci 2016;93:872–80.
24. Guillon M, Dumbleton KA, Theodoratos P, Wong S, Patel K, Banks G, Patel T. Association between contact lens discomfort and pre-lens tear film kinetics. Optom Vis Sci 2016;93:881–91.
25. Lopez-de la Rosa A, Martin-Montanez V, Lopez-Miguel A, Calonge M, Enriquez-de-Salamanca A, Gonzalez-Garcia MJ. Corneal sensitivity and inflammatory biomarkers in contact lens discomfort. Optom Vis Sci 2015;93:892–900.
26. Situ P, Simpson T, Begley C. Hypersensitivity to cold stimuli in symptomatic contact lens wearers. Optom Vis Sci 2016;93:909–16.
27. Stapleton F, Marfurt C, Golebiowski B, Rosenblatt M, Bereiter D, Begley C, Dartt D, Gallar J, Belmonte C, Hamrah P, Willcox M, members of the TFOS International Workshop on Contact Lens Discomfort. The TFOS International Workshop on Contact Lens Discomfort: report of the subcommittee on neurobiology. Invest Ophthalmol Vis Sci 2013;54:TFOS71–97.
28. Efron N, Jones L, Bron AJ, Knop E, Arita R, Barabino S, McDermott AM, Villani E, Willcox MD, Markoulli M, members of the TFOS International Workshop on Contact Lens Discomfort. The TFOS International Workshop on Contact Lens Discomfort: report of the contact lens interactions with the ocular surface and adnexa subcommittee. Invest Ophthalmol Vis Sci 2013;54:TFOS98–122.
29. Lievens CW, Kannarr S, Zoota L, Lemp J. Lid papillae improvement with hydrogen peroxide lens care solution use. Optom Vis Sci 2016;93:933–42.
30. Jones L, Brennan NA, Gonzalez-Meijome J, Lally J, Maldonado-Codina C, Schmidt TA, Subbaraman L, Young G, Nichols JJ, members of the TFOS International Workshop on Contact Lens Discomfort. The TFOS International Workshop on Contact Lens Discomfort: report of the contact lens materials, design, and care subcommittee. Invest Ophthalmol Vis Sci 2013;54:TFOS37–70.
31. Tankam P, Won J, Canavesi C, Cox I, Rolland JP. Optical assessment of soft contact lens edge-thickness. Optom Vis Sci 2016;93:987–96.
32. Masoudi S, Stapleton FJ, Willcox MD. contact lens-induced discomfort and protein changes in tears. Optom Vis Sci 2016;93:955–62.
33. Berntsen DA, Hickson-Curran SB, Jones LW, Mathew JH, Maldonado-Codina C, Morgan PB, Schulze MM, Nichols JJ; Performance of Contact Lens Solutions Study Group. Subjective comfort and physiology with modern contact lens care products. Optom Vis Sci 2016;93:809–19.
34. Cox SM, Berntsen DA, Chatterjee N, Hickson-Curran SB, Jones LW, Moezzi AM, Morgan PB, Nichols JJ; Performance of Contact Lens Solutions Study Group. Eyelid margin and meibomian gland characteristics and symptoms in lens wearers. Optom Vis Sci 2016;93:901–8.
35. Schulze MM, Srinivasan S, Hickson-Curran SB, Berntsen DA, Howarth GF, Toubouti Y, Morgan P, Nichols JJ, Jones LW; Performance of Contact Lens Solutions Study Group. Lid wiper epitheliopathy in soft contact lens wearers. Optom Vis Sci 2016;93:943–54.
36. Alzahrani Y, Colorado L, Pritchard N, Efron N. Inflammatory cell upregulation of the lid wiper in contact lens dry eye. Optom Vis Sci 2016;93:917–24.
37. Shigeyasu C, Yamada M, Akune Y, Fukui M. Diquafosol for soft contact lens dryness: clinical evaluation and tear analysis. Optom Vis Sci 2016;93:973–8.
38. Nichols JJ, Lievens CW, Bloomenstein MR, Liu H, Simmons P, Vehige J. Dual-polymer drops, contact lens comfort, and lid wiper epitheliopathy. Optom Vis Sci 2016;93:979–86.
39. Naduvilath T, Papas EB, Lazon de la Jara P. Demographic factors affect ocular comfort ratings during contact lens wear. Optom Vis Sci 2016;93:1004–10.