Is Demodex playing a role in dropouts?

The primary reason for contact lens dropout is discomfort. But why are patients uncomfortable? Is it because of the lens material, the lens solution, or ocular surface disease? Or, is it due to Demodex?

THE CONTACT LENS LINK

A study by Jalbert and Rejab reveals that 90% of contact lens wearers had Demodex, vs. 65% of non-wearers.¹ The theory proposed for this finding was that contact lens wear impacts the lid margin health and natural bacteria levels, making it a more conducive environment for the Demodex.

Additionally, a study by Tarkowski et al shows that approximately 93% of patients with contact lens intolerance were positive for Demodex.²

WHAT WE CAN DO

• Promote lid hygiene. We should promote healthy lids in patients wearing and not wearing contact lenses before we see a Demodex infestation. Lid hygiene is key. The lids should be cleaned twice a day with either prepackaged lid scrubs or spray — I prefer those that contain hypochlorous acid. We should also educate patients about how to use lid scrubs. Often, patients aren’t sure how to effectively perform this task, and return for follow-up with little-to-no improvement as a result.Patients who wear makeup should be reminded to use non-waterproof products, replace mascara at least every three months, clean brushes, and remove makeup at night. A step further would be to suggest eye-friendly makeup.
• Perform a slit lamp exam, utilizing vital dyes. Demodex presents as biofilm on the lid margin and collarettes at the base of the eyelashes. Pro tip: Have patients look down when under the slit lamp. This allows us to better identify collarettes at the base of the eyelashes on the upper lid that will be missed when viewing the eyelid straight on.
  Of note: Demodex infestations are more likely in patients who also have concurrent blepharitis, with increase in bacteria, including staphylococcus epidermidis and staph. aureus.^3,4
• Prescribe lid cleaning with a product that contains tea tree oil. When Demodex blepharitis is noted, we should start or switch the lid hygiene to this approach and, depending on the severity, debride the bulk of the collarettes in-office to make the at-home hygiene — twice-a-day, for two weeks — more effective. Patients who have Demodex infestation flares may need to remain on this regimen. (TP-03, from Tarsus Pharmaceuticals, is a potential treatment currently in Phase 3 studies.)⁵ OM

REFERENCES

1. Jalbert I and Rejab S. Increased numbers of Demodex in contact lens wearers. Optom Vis Sci. 2015;92(6):671-678. doi: 10.1097/OPX.0000000000000605.
2. Tarkowski W, Moneta-Wielgoś J, Młocicki D. Demodex sp. as a Potential Cause of the Abandonment of Soft Contact Lenses by Their Existing Users. Biomed Res Int. 2015;2015:259109. doi: 10.1155/2015/259109.
3. Luo X, Li J, Chen C, Tseng S, Liang L. Ocular Demodicosis as a Potential Cause of Ocular Surface Inflammation. Cornea. 2017;36 Suppl 1(Suppl 1):S9-S14. doi: 10.1097/ICO.0000000000001361.
4. Lee SH, Chun YS, Kim JH, Kim ES, Kim JC. The relationship between demodex and ocular discomfort. Invest Ophthalmol Vis Sci. 2010;51(6):2906-11. doi: 10.1167/iovs.09-4850. Epub 2010 Feb 3.
5. Tarsus Pharmaceutical Inc. Presents New Saturn-1 Pivotal Trial Data and Titan Real-World Prevalence Study Results at ASCRS”. https://tinyurl.com/2p9xt63p . Accessed Nov. 10, 2021.

DR. KOETTING practices at Hines-Sight in Denver, Colo. She is a fellow of the American Academy of Optometry, diplomate of the American Board of Optometry, an active member of AOA, and a speaker and consultant for multiple companies. Follow her on Instagram at Dr_Jazz_Hands, or email her at Dr.CeceliaKoetting@gmail.com.