Standards for contact lens (CL) hygiene and compliance are provided by the CL manufacturing industry, regulatory agencies, and CL-related professional associations. Images of water are sometimes used in CL marketing and packaging materials (Arshad et al, 2019).

However, when CLs are exposed to water, ocular complications ranging from sterile corneal infiltrative events to sight-threatening infections may occur due to the transfer of pathogenic microorganisms to the eye (Carnt et al, 2017; Arshad et al, 2019). In soft contact lens wear, the most substantial risk factors for microbial keratitis (MK) are poor hygiene, overnight lens wear, and exposure to tap water (Carnt et al, 2017).

A review of the literature showed that regardless of the documented risks due to water exposure, water-related habits are common among CL wearers (Arshad et al, 2019). The use of tap water, swimming and water-based sporting activities, and showering/bathing with CLs have been related to an increased risk of ocular complications and an increased risk of Acanthamoeba keratitis, which can be sight threatening (Wolffsohn et al, 2021).

Although showering with CLs can be devastating, it is common, with estimates ranging from 29% to 86% (Wolffsohn et al, 2021). Swimming with lenses is also widespread—estimates range from 25% to 68% (Wolffsohn et al, 2021). Tap water is also used inappropriately for case cleaning. There are other ways tap water can be introduced into the eye; for example, in a survey of teenagers, more than 50% admitted to wearing lenses that they had dropped in the sink (Abbouda et al, 2016).

Exposure and Contamination

A study assessed the effect of water exposure and storage case contamination in soft CL wearers (Arshad et al, 2021a). A self-administered questionnaire was completed by 165 daily soft lens wearers (average age, 28 years; 65% were female).

CL cases were sampled, and microbial analyses conducted for total microbial bioburden and endotoxin levels. Compliance was measured by lens hygiene (excellent, > 35; moderate, 28 to 35; poor, < 28). Water contact (≤ 1, good; > 1, poor) quantified water exposure during CL wear. Multiple regression analysis determined the connection of water behaviors and case contamination.

Microbial bioburden of storage cases on average was 3.10 (0.98) log colony-forming unit/mL (1.09 to 5.94 log colony-forming unit/mL). Showering was reported in 45% of participants, 49.7% reported swimming while wearing lenses (65.4% swam without goggles), 27.8% used wet hands to handle lenses, and 17.5% used tap water to rinse storage cases. The risk of higher storage case bioburden (P = .001) was significantly increased with showering. Wet hands (P = .01) doubled the risk of higher case endotoxin levels (odds ratio, 2.41; confidence interval 1.19 to 4.86).

Water contact behavior while wearing CLs is widespread among soft lens wearers and is related to higher case contamination (Arshad et al, 2021a). It is pertinent for practitioners to improve CL education to reduce water exposure and case contamination to lessen the risk of CL-related adverse events.

In Summary

Guidelines should clearly advocate for the avoidance of any water exposure, including handling CLs with wet hands, rinsing contact lenses or storage cases in tap water, and showering or swimming with CLs. A practical recommendation of a “no-water” infographic on CL cases improves overall water-contact behaviors (Arshad et al, 2021b). Additionally, this graphic was shown to reduce storage case endotoxin (a toxin of Gram-negative bacteria, also called lipopolysaccharide) (Arshad et al, 2021b). Thus, a consensus among practitioners and industry about water and CL care is needed for safe and healthy CL wear. CLS

References

1. Arshad M, Carnt N, Tan J, Ekkeshis I, Stapleton F. Water Exposure and the Risk of Contact Lens-Related Disease. Cornea. 2019 Jun;38:791-797.
2. Carnt N, Samarawickrama C, White A, Stapleton F. The diagnosis and management of contact lens-related microbial keratitis. Clin Exp Optom. 2017 Sep;100:482-493.
3. Wolffsohn JS, Dumbleton K, Huntjens B, et al. CLEAR - Evidence-based contact lens practice. Cont Lens Anterior Eye. 2021 Apr;44:368-397.
4. Abbouda A, Restivo L, Bruscolini A, et al. Contact Lens Care among Teenage Students in Italy: A Cross-Sectional Study. Semin Ophthalmol. 2016;31:226-232.
5. Arshad M, Carnt N, Tan J, Stapleton F. Effect of Water Exposure on Contact Lens Storage Case Contamination in Soft Lens Wearers. Optom Vis Sci. 2021 Sep 1;98:1002-1010.
6. Arshad M, Carnt N, Tan J, Stapleton F. Compliance behaviour change in contact lens wearers: a randomised controlled trial. Eye (Lond). 2021 Mar;35:988-995.