Contact Lenses for Dry Eye Patients: To Fit or Not to Fit

Contact lens discomfort is defined by the TFOS International Workshop on Contact Lens Discomfort as an episodic or persistent adverse ocular sensation related to contact lens wear that occurs, with or without visual disturbance, due to incompatibility between contact lens and ocular surface, and can lead to decreased contact lens wear time and eventual dropout.^1,2

It is a major concern for both patients and practitioners and is frequently noted among patients, with estimates as high as 50% of contact lens wearers experiencing varying degrees of discomfort.²

Studies have reported between 12-51% of lens dropout is due to contact lens discomfort.²

The interaction between a contact lens and the ocular surface can have several ramifications. Contact lenses disrupt the natural tear dynamics and create a pre-lens and post-lens tear film.² This partitioning of the tear film can result in an unstable pre-lens tear film that has a reduced lipid layer and tear volume and increased tear evaporation.^2-4

In addition, there have been reports of alterations to conjunctival anatomy, both bulbar and palpebral. Studies have also linked bulbar conjunctival staining due to soft lens edge design and modulus.² Similarly, for palpebral conjunctiva, there have been associations between alterations to meibomian glands and lid wiper zone.² These interactions can disrupt homeostasis of the ocular surface and increase ocular discomfort if not addressed.^2-4

Contact lens-related dry eye is a multifactorial condition and is influenced by a variety of different factors. Contact lens attributes such as water content, dehydration, modulus, mechanical factors, material, and care products can significantly influence ocular comfort and wearability of lenses. In addition, it is important to consider other factors such as a patient's systemic conditions, medications, the ocular environment (i.e., tear film stability), and environmental factors to determine a multifaceted approach in management of contact lens wear in dry eye patients and to reduce contact lens dropout.^2,3

Assessing symptoms

The first step in managing patients with contact lens discomfort is to assess their symptoms to establish a baseline. Any modifications in treatment should also be assessed to gauge the effectiveness of the management plan. Utilizing questionnaires such as the Ocular Surface Disease Index (OSDI) or Contact Lens Dry Eye Questionnaire can be useful in measuring the frequency and severity of patient symptoms.^5-7

Dry eye measurements

It is important to monitor the tear dynamics, conjunctival anatomy, and meibomian gland function to understand the influence of contact lens wear on the ocular surface environment. Patients with reduced tear film break up time, tear prism height, lid wiper epitheliopathy, staining, and meibomian gland dysfunction are at higher risk of symptomatic discomfort and intolerance with contact lens wear.⁵

Once baseline assessments and measurements have been obtained, alterations can be made to contact lenses to address the clinical signs and provide symptomatic relief to patients.

Contact lens material and replacement schedule

Modifying replacement schedule

Over time, soft contact lenses show a reduction in comfort and wettability. Many studies have corroborated that changing the replacement schedule of contact lenses can result in significantly better end-of-the-day comfort and dryness. Switching patients to daily disposables with increased surface water content can help with increasing wettability, lubricity, and reduce tear film disruption, thus maximizing comfort.^2-5,8-9

Appropriate selection of contact lens material

The newer silicone hydrogel material offers a higher Dk/t and low equilibrium water content (EWC) over traditional hydrogel lenses. It was initially believed that higher EWC allowed the lenses to be more wettable and improve comfort, however, it soon became apparent that with higher water content hydrogels, dehydration became more pronounced which reduced end of the day comfort. Silicone hydrogels offer a low EWC, but there are confounding variables such as material properties (i.e, oxygen transmissibility, modulus, and surface wetting properties that make it difficult to draw solid conclusions about their comfort in comparison to hydrogels).

Nonetheless, multiple studies have shown an improvement in symptoms of dryness when switching patients from hydrogel to silicone hydrogel lenses, so it is worthwhile converting patients to a SiHy material in cases of contact lens discomfort.^{2, 10-13}

Contact lens solutions and tear supplements

Contact lens solutions

Preservatives from lens care systems have been linked with contact lens discomfort in patients. One option is to switch patients to daily disposable lenses as it reduces the interactions between contact lens solutions and the ocular surface. Level 2 studies have reported greater comfort and less subjective dryness when patients used daily disposable lenses in comparison to lenses used with care systems.^2,3,5,14-16

Tear supplements

Contact lens discomfort can present with clinical signs of lid wiper epitheliopathy, conjunctival staining, and reduced tear break up time. The use of external lubrication agents such as polyvinyl alcohol, sodium hyaluronate and other non-preserved lipid supplements can improve comfort and tear break up. In addition, lubricating drops can minimize friction between the ocular surface and the eyelids reducing dry eye symptoms.^2-4

Clinical takeaways

Contact lens discomfort can pose significant clinical challenges during fitting. Its management requires a thorough assessment of risk factors for dry eye and understanding contact lens material properties to provide individualized care. Substitution of lens materials, altering contact lens replacement schedule, or care products can help in improving comfort and contact lens tolerance.

In addition, it is important to remember that concurrently managing dry eyes is crucial in long term management of contact lens patients to prevent dropout.

References

Nichols, K.K., Redfern, R.L., Jacob, J.T, et al. The TFOS International Workshop on Contact Lens Discomfort: Report of the Definition and Classification Subcommittee. Invest Ophthalmol Vis Sci. 2013: 54-TFOS19.
Nichols, J.J., Wilcox, M.D.P., Bron, A.J., et al. The TFOS International Workshop on Contact Lens Discomfort: Executive Summary. Invest Ophthalmol Vis Sci. 2013: 54-TFOS7-13.
Harthan, J.S., Hom, M.M. It’s All About the Tear Film. Review of Cornea & Contact Lenses. 2017: 24-27
Rohit, A., Willcox, M.D.P., Brown, S.H.J., et al. Clinical and biochemical tear lipid parameters in contact lens wearers. Optom Vis Sci. 2014;91:1384-90.
Fuller, D. Yes, Dry Eye Patients Can Wear Contacts. Review of Optometry. 2015:40-48
Chalmers, R.L., Begley, C.G., Moody, K., et al. Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and opinion of contact lens performance. Optom Vis Sci. 2012: 89(10):1435-42.
Nichols, J.J., Mitchell, G.L., Nichols, K.K., et al. The performance of the contact lens dry eye questionnaire as a screening survey for contact lens-related dry eye. Cornea. 2002;21(5):469-75.
Poggio, E.C., Abelson, M. Complications and symptoms in disposable extended wear lenses compared with conventional soft daily wear and soft extended wear lenses. CLAO J. 1993;19:31-9.
Malet, F., Schnider, C.M. Influence of replacement schedule and care regimen on patient comfort and satisfaction with daily wear frequent-replacement contact lenses. CLAO J. 2002;28: 124–127.
Chalmers, R., Long, B., Dillehay, S., et al. Improving contact lens related dryness symptoms with silicone hydrogel lenses.Optom Vis Sci. 2008;85(8):778–84.
Fonn, D., Dumbleton, K. Dryness and discomfort with silicone hydrogel contact lenses. Eye Contact Lens. 2003;29 (1 Suppl):S101–S104.
Fonn, D., Situ, P., Simpson, T. Hydrogel lens dehydration and subjective comfort and dryness ratings in symptomatic and asymptomatic contact lens wearers. Optom Vis Sci. 1999;76: 700–704.
Dumbleton, K.A., Woods, C.A., Jones, L.W., et al. Comfort and adaptation to silicone hydrogel lenses for daily wear. Eye Contact Lens. 2008;34:215–223.
Tilia, D., Lazon de la Jara, P., Peng, N., et al. Effect of lens and solution choice on the comfort of contact lens wearers. Optom Vis Sci. 2013;90(5):411–8.
Willcox, M.D., Phillips, B., Ozkan, J., et al. Interactions of lens care with silicone hydrogel lenses and effect on comfort. Optom Vis Sci. 2010;87:839-46.
Campbell, R., Kame, G., Leach, N., et al. Clinical benefits of a new multipurpose disinfecting solution in silicone hydrogel and soft contact lens users. Eye Contact Lens. 2012;38:93-101.