We have long been aware of the dangers of smoking, yet smoking is still a major health concern within the United States (U.S. Food and Drug Administration [FDA], 2016). Cigarettes contain more than 4,000 harmful compounds such as nicotine, carbon monoxide, tar, and a number of heavy metals (Chiba and Masironi, 1992; Satici et al, 2003). The FDA indicates that smoking increases the risk for developing cardiovascular disease, stroke, cancer, type 2 diabetes, and birth defects, issues that result in about a half a million deaths each year in the United States alone (FDA, 2016).
Smoking can also have a profound effect on the eyes. Specifically, smoking has been associated with increased risk of developing conditions such as cataracts, macular degeneration, and diabetic retinopathy (Asfar et al, 2015). Smoking can also result in deleterious ocular surface changes that can have an impact on contact lens wearers.
Ocular Signs and Symptoms
Many smokers experience ocular symptoms, likely instigated by the harmful gases and compounds that are emitted by cigarettes (Satici et al, 2003; Matsumoto et al, 2008). Cigarette smoking has also been associated with a number of ocular surface changes. Smokers have been noted to have faster tear evaporation rates, lower-quality tear lipid layers, and increased corneal staining (Matsumoto et al, 2008; Lee et al, 2012).
Decreased tear stability in smokers has been corroborated with data suggesting that smokers also have excessive tearing (Satici et al, 2003). Excessive tearing is not only irritating to patients, but it may also have additional negative consequences. Smokers who have watery eyes have been found to have decreased tear lysozyme concentrations; decreased lysozyme levels may subsequently result in a reduced immune response to pathogenic bacteria (Satici et al, 2003).
Lastly, smoking has been associated with ocular surface cellular changes such as conjunctival squamous metaplasia and reduced goblet cell densities (Matsumoto et al, 2008).
Increased Risk of Contact Lens Complications
Smoking has been associated with increased risk of contact lens contamination (Jiang et al, 2014). Being a smoker can also increase the likelihood of experiencing corneal infiltrative events (Jiang et al, 2014; Szczotka-Flynn et al, 2010), and smokers are about three times more likely to develop microbial keratitis (Stapleton et al, 2012).
It is currently unclear whether smoking itself increases the risk for these conditions or whether smokers are more likely to develop contact lens complications because this population also tends to engage in riskier behaviors (Szczotka-Flynn et al, 2010).
Corneal Wound Healing
In addition to being at a greater risk for developing ocular complications, smokers’ eyes have a reduced ability to heal. Specifically, Roszkowska et al (2013) found that smokers have a decreased ability to re-epithelialize after photorefractive keratectomy. This is especially problematic for contact lens wearers because contact lens use can result in mechanical damage to the cornea, chronic damage that a smokers’ eye has a reduced ability to correct (Roszkowska et al, 2013).
The Centers for Medicare & Medicaid Services (2016) currently requires that we ask all patients who are 13 years and older about smoking status to meet meaningful use requirements.
While asking this question and providing patients who smoke with appropriate education, you may want to include in your education that smoking increases their risk of having uncomfortable eyes and developing inflammatory and infective conditions that may prevent them from wearing contact lenses (Szczotka-Flynn et al, 2010; Stapleton et al, 2012). You should also direct your patients to resources such as those offered by the Centers for Disease Control and Prevention (CDC) on how to stop smoking (CDC, 2016). CLS
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