This article was originally published in a sponsored newsletter.

Disrupted ocular surface homeostasis is a hallmark of dry eye disease (DED).^1,2 The loss of tear film homeostasis is the central pathophysiological concept in the current definition of the multifactorial nature of DED.³ Ocular surface homeostasis is subject to a balance of tear production and evaporation. When evaporation exceeds total tear supply, the result is desiccation stress, damage, and inflammation in DED.^1,2 In DED, numerous cytokines/chemokines are elevated in the tears, comprising of TNF-α, IL-6, IL-17a, and IL-8.⁴
 
A prospective study evaluated ocular surface homeostasis after scleral lens wear.⁵ The study examined the effects of scleral lens wear on tear film cytokine expression were evaluated in 23 healthy patients. A single eye of each patient was randomly selected and fit by an experienced contact lens practitioner with a 16.5mm diameter scleral lens. The scleral lens was worn for five hours.
 
Capillary tubes were used to collect precorneal tear fluid at three different time points; prior to scleral lens application, after five hours of scleral lens wear and three hours after scleral lens removal. At each time point, multiplex bead assay was used to analyze the concentration of 40 inflammatory cytokines.⁵ In healthy eyes, the cytokine-to-protein ratio after five hours of scleral lens wear did not cause significant changes.

At the time of publication, a contact lens-integrated cytokine sensor has not been manufactured.⁴ However, the practicality of integrating antibody-functionalized sensors into thin flexible polymer membranes for continuous study of analytes has been reported.⁴
 
This potential new technology integrated into a contact lens may offer an uninterrupted monitoring system for tear film cytokines. This technology may be a helpful tool in the diagnosis and monitoring of DED, contact lens discomfort, and additional ocular surface diseases.⁴

REFERENCES

1. Bron AJ, de Paiva CS, Chauhan SK, et al. TFOS DEWS II pathophysiology report. Ocul Surf. 2017 Jul;15:438-510.

2. McMonnies CW. Aqueous deficiency is a contributor to evaporation-related dry eye disease. Eye Vis (Lond). 2020 Feb 1;7:6.

3. Craig JP, Nichols KK, Akpek EK, et al. TFOS DEWS II Definition and Classification Report. Ocul Surf. 2017 Jul;15:276-283.

4. Jones L, Hui A, Phan CM, et al. CLEAR - Contact lens technologies of the future. Cont Lens Anterior Eye. 2021 Apr;44:398-430.

5. Ballet B, Behaegel J, Reppe S, et al. Ocular Surface Homeostasis After Scleral Lens Usage. Eye Contact Lens. 2023 Nov 1;49:459-463.

Melissa Barnett, OD, FAAO, FSLS, is the Director of Optometry at the University of California, Davis, specializing in anterior segment disease and specialty contact lenses. She is the past president of the Scleral Lens Education Society and is past chair of American Optometric Association Contact Lens and Cornea Section. She is an advisor to and/or has received honoraria or travel expenses from AccuLens, Alcon, Allergan, Bausch + Lomb, Bruder, Contamac, CooperVision, Johnson & Johnson Vision, Ocusoft, ScienceBased Health, Tarsus, and Visus Therapeutics.