The effect of active smoking, passive smoking, and e-cigarettes on the tear film: An updated comprehensive review

The Impact of Vaping on the Ocular Surface: A Systematic Review of the Literature

Background: The use of electronic cigarettes has become increasingly popular in recent years. However, the impact that electronic cigarettes have on the ocular surface is not well known. Therefore, the aim of this review is to explore the current literature on the acute and chronic sequelae of electronic cigarettes on the ocular surface. Methods: A systematic review of the literature was undertaken by keyword searching on the Embase, Medline, and Web of Science databases. Articles identified through the search underwent title/abstract screening, full-text screening, and data extraction. Results: A total of 18 studies were included in this review. Non-intended ocular surface exposures and intended exposures on the ocular surface were found to be associated with the use of electronic cigarettes. Conclusions: The impact of vaping on the ocular surface is not benign. There are significant risks that vaping can pose to the ocular surface. Hence, it is necessary to develop appropriate risk communication tools given the increasing popularity of this activity. Additionally, future long-term studies are needed to better understand the long-term impacts of vaping on the ocular surface given the lack of current data.

Tear biomarkers

An extensive exploration of lacrimal fluid molecular biomarkers in understanding and diagnosing a spectrum of ocular and systemic diseases is presented. The chapter provides an overview of lacrimal fluid composition, elucidating the roles of proteins, lipids, metabolites, and nucleic acids within the tear film. Pooled versus single-tear analysis is discussed to underline the benefits and challenges associated with both approaches, offering insights into optimal strategies for tear sample analysis. Subsequently, an in-depth analysis of tear collection methods is presented, with a focus on Schirmer's test strips and microcapillary tubes methods. Alternative tear collection techniques are also explored, shedding light on their applicability and advantages. Variability factors, including age, sex, and diurnal fluctuations, are examined in the context of their impact on tear biomarker analysis. The main body of the chapter is dedicated to discussing specific biomarkers associated with ocular discomfort and a wide array of ocular diseases. From dry eye disease and thyroid-associated ophthalmopathy to keratoconus, age-related macular degeneration, diabetic retinopathy, and glaucoma, the intricate relationship between molecular biomarkers and these conditions is thoroughly dissected. Expanding beyond ocular pathologies, the chapter explores the applicability of tear biomarkers in diagnosing systemic diseases such as multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and cancer. This broader perspective underscores the potential of lacrimal fluid analysis in offering non-invasive diagnostic tools for conditions with far-reaching implications.

Ocular Symptoms in Adolescents and Young Adults With Electronic Cigarette, Cigarette, and Dual Use

Importance

Despite increasing use of cigarettes and electronic cigarettes (e-cigarettes) and related health effects among youth, few studies have reported their effects on eyes.

Objective

To examine the frequency and severity of ocular symptoms (ocular discomfort, pain, burning, itching, redness, dryness, glare, blurriness, strain, and headaches) in young e-cigarette and cigarette users.

Design, Setting, and Participants

In an observational cross-sectional study, a survey conducted in May 6 to 14, 2020, asked participants about use (ever, past 30 days, and past 7 days) of e-cigarettes and cigarettes. The participants included US individuals aged 13 to 24 years.

Main Outcomes and Measures

Associations between vision-related outcomes (general vision, severity/frequency of ocular symptoms) and tobacco use were analyzed using weighted multivariable logistic regressions, adjusting for sociodemographic factors, contact lens use, and other combustible use.

Results

There were 2168 never users, 2183 ever users, 1092 past 30-day users, and 919 past 7-day users of e-cigarettes; 55.9% of e-cigarette ever users also used cigarettes (dual users). Of the 4351 respondents, 63.8% identified as female, and mean (SD) age was 19.1 (2.9) years. Between 1.1% and 3.9% of ever dual users reported severe to very severe ocular symptoms; between 0.9% and 4.3% reported daily symptoms, which was higher than the proportion of symptoms in e-cigarette- or cigarette-only users. Past 7-day dual users had more severe itching (adjusted odds ratio [AOR], 2.37; 95% CI, 1.36-4.13; P = .002), redness (AOR, 2.58; 95% CI, 1.50-4.46; P = .001), dryness (AOR, 2.89; 95% CI, 1.64-5.08; P < .001), glare (AOR, 2.56; 95% CI, 1.50-4.35; P = .001), blurriness (AOR, 2.47; 95% CI, 1.36-4.50; P = .003), headaches (AOR, 2.31; 95% CI, 1.34-4.00; P = .003); and more frequent pain (AOR, 3.45; 95% CI, 2.09-5.68; P < .001), burning (AOR, 3.08; 95% CI, 1.86-5.09; P < .001), and redness (AOR, 2.72; 95% CI, 1.69-4.36; P < .001) than all other participants. Past 30-day dual users had more severe dryness (AOR, 2.65; 95% CI, 1.61-4.36; P < .001) and more frequent pain (AOR, 3.33; 95% CI, 2.12-5.21; P < .001) than all other participants. Ever dual users experienced more severe dryness (AOR, 1.60; 95% CI, 1.05-2.43; P = .03) and blurriness (AOR, 1.79; 95% CI, 1.21-2.64; P = .003) and more frequent pain (AOR, 1.69; 95% CI, 1.13-2.53; P = .01) and blurriness (AOR, 1.63; 95% CI, 1.13-2.36; P = .009) than never users.

Conclusions and Relevance

In this cross-sectional US study, adolescents and young adult users of both e-cigarettes and cigarettes had a higher likelihood of experiencing severe and frequent ocular symptoms, with past 7-day users reporting more symptoms than past 30-day users or ever users. These findings provide additional reasons for users of e-cigarettes and cigarettes to reduce their tobacco use to possibly prevent or minimize ocular symptoms.

TFOS lifestyle: Impact of societal challenges on the ocular surface

Societal factors associated with ocular surface diseases were mapped using a framework to characterize the relationship between the individual, their health and environment. The impact of the COVID-19 pandemic and mitigating factors on ocular surface diseases were considered in a systematic review. Age and sex effects were generally well-characterized for inflammatory, infectious, autoimmune and trauma-related conditions. Sex and gender, through biological, socio-economic, and cultural factors impact the prevalence and severity of disease, access to, and use of, care. Genetic factors, race, smoking and co-morbidities are generally well characterized, with interdependencies with geographical, employment and socioeconomic factors. Living and working conditions include employment, education, water and sanitation, poverty and socioeconomic class. Employment type and hobbies are associated with eye trauma and burns. Regional, global socio-economic, cultural and environmental conditions, include remoteness, geography, seasonality, availability of and access to services. Violence associated with war, acid attacks and domestic violence are associated with traumatic injuries. The impacts of conflict, pandemic and climate are exacerbated by decreased food security, access to health services and workers. Digital technology can impact diseases through physical and mental health effects and access to health information and services. The COVID-19 pandemic and related mitigating strategies are mostly associated with an increased risk of developing new or worsening existing ocular surface diseases. Societal factors impact the type and severity of ocular surface diseases, although there is considerable interdependence between factors. The overlay of the digital environment, natural disasters, conflict and the pandemic have modified access to services in some regions.

Physical Properties and Interaction With the Ocular Surface of Water-Gradient Contact Lenses

ABSTRACT

Since the introduction of silicone hydrogel contact lenses, many silicone-hydrogel materials have been produced, including water-gradient contact lenses with a silicone hydrogel core and a thin hydrogel outer layer (e.g., delefilcon A, verofilcon A, and lehfilcon A). Their properties have been investigated in various studies assessing both the chemical-physical characteristics and the comfort, but the overall picture is not always consistent. In this study, water-gradient technology is reviewed by looking at basic physical properties both in vitro and in vivo and at the interaction with the human ocular surface. Surface and bulk dehydration, surface wetting and dewetting, shear stress, interaction with tear components and with other environmental compounds, and comfort are discussed.

Smoking and environmental tobacco smoke exposure: implications in ocular disorders

PURPOSE

This article aims to gather and review the available knowledge on several implications of smoking and environmental tobacco smoke (ETS) exposure in ocular disorders and provides pathomechanistic insights where applicable.

MATERIALS AND METHODS

PubMed and Scopus databases were searched for relevant studies on the association of smoking and ETS exposure with various ocular disorders. Studies with different evidence levels, e.g., in-vivo, case-control, cohort, and meta-analysis, were included.

RESULTS

Smoking is an established, modifiable risk factor in several ocular diseases, including cataract, age-related macular degeneration, and Graves' ophthalmopathy; smokers are subject to more severe disease courses and less favorable treatment outcomes. Uveitis is twice as likely in smokers; smoking may also delay its resolution. Smoking and ETS exposure are major risk factors for diseases of other organs, with associated ocular complications as well, such as diabetes mellitus. ETS exposure is also associated with ocular surface pathologies, including dry eye syndrome. In children, early-life ETS exposure and maternal smoking during pregnancy are strongly associated with refractive errors and strabismus. Currently, available data on potential risks attributable to ETS exposure regarding ocular diseases are scarce and, in some instances, controversial.

CONCLUSION

In addition to smoking, ETS exposure is also a significant public health concern with possible links to several ocular diseases. However, the level of education of at-risk populations in this regard does not match the strength of the evidence.

Impact of Electronic Cigarettes on the Upper Aerodigestive Tract: A Comprehensive Review for Otolaryngology Providers

Objective

The use and effects of electronic (e)-cigarettes (e-cigs) are particularly relevant for otolaryngology providers as tobacco plays a major role in benign and malignant diseases of the upper aerodigestive tract. This review aims to (1) summarize the recent policies regarding e-cigs and important patterns of use and (2) serve as a comprehensive resource for clinical providers on the known biologic and clinical effects of e-cigs on the upper aerodigestive tract.

Data Sources

PubMed/MEDLINE.

Review Methods

We conducted a narrative review on (1) general information on e-cig use and informative findings in the lower respiratory system and a comprehensive review on (2) the effects of e-cigs on cell and animal models and the clinical implications of these products on human health as is relevant to otolaryngology.

Conclusions

Although e-cigs are likely less harmful than conventional cigarettes, preliminary research on e-cigs suggest several deleterious effects including in the upper aerodigestive tract. Due to this, there has been increased interest in restricting e-cig usage, particularly among the adolescent population, and caution in recommending e-cigs to current smokers.

Implications for Practice

Chronic e-cig use is likely to have clinical implications. It is critical for otolaryngology providers to be aware of the rapidly changing regulations and use patterns regarding e-cigs and how e-cigs influence human health, particularly with regards to the upper aerodigestive tract, to accurately council patients regarding potential risks and benefits of use.

In vitro affinity for nicotine of soft contact lenses of different materials

Smoking is a risk factor for the development of microbial keratitis and corneal infiltrates in contact lens (CL) wearers. It is still unknown if this risk is directly associated with the presence of nicotine in the eye and if adherence of nicotine on the CL can enhance these effects. A better understanding of the interaction between nicotine and CL materials could offer insights to explain this risk associated with smoking. The aim of this work was to compare the affinity of nicotine to different soft CL materials. CLs from FDA groups I, II, IV, and V were incubated in a 2-mM nicotine solution for 24 h and then in a 0.9% saline solution for the next 24 h. The amount of absorbed and released nicotine per CL was deduced as a function of time (t) by ultraviolet (UV) spectrophotometry and normalised to the mass of the hydrated CL. The data were described by the equation y = b -a t^-1, where a and b are constants, and b represents the mass reached at the plateau after ~ 10 min of exposure. Groups IV and V displayed the highest (0.80 ± 0.09 µg) and lowest (0.27 ± 0.08 µg) nicotine absorption per mg of hydrated CL, respectively. The CL affinity for nicotine could be ascribed to the interaction between the positive charge of nicotine pyrrolidine nitrogen and the negative charges of the CLs, especially for the ionic IV group.