I would like to share a synopsis of a literature review characterizing dry eye disease in a younger demographic (< 40 years old) versus an older demographic (> 60 years old) and highlight the differences in this multifactorial disease between these age subsets (Barabino, 2022).

Although dry eye disease is observed in patients of all ages, the incidence in young people is increasing (Talens-Estarelles et al, 2020). It has been noted that younger patients are more symptomatic and have more total and incomplete blinks. It has been suggested that this is because younger patients have a higher corneal nerve density and perhaps a lower pain threshold (Weng et al, 2021). Younger patients have a lower mean lipid layer thickness, but a higher number of functioning meibomian glands. Their thinner lipid layer provides weak tear evaporation protection, precipitating more, but less effective, incomplete blinks that do not pump sufficient meibum for the meibomian glands (Weng et al, 2021).

The primary drivers of dry eye in the younger subset of patients were demonstrated to be digital device use, contact lens wear, and desiccating/detrimental work or recreational environments, including excessive sunlight (Weng et al, 2021; Sliney, 2002). Prolonged attention to digital displays/operation can precipitate a reduced blink rate and incomplete eyelid closure, high visualization angles leading to increased palpebral fissures, and dysfunction of the meibomian glands (Talens-Estarelles et al, 2021).

Additionally, reduction in tear volume and stability, altered composition and increased osmolarity, expression of inflammatory cytokines and oxidative stress markers, reduced mucin secretion, corneal and conjunctival staining, and bulbar injection are described as consequences of digital display use (Talens-Estarelles et al, 2021).

In contrast, elderly patients who have dry eye disease have been found to have milder symptoms compared to patients under 41 years, albeit with a lower number of functioning meibomian glands (Weng et al, 2021). Altered blinking is less frequent in the elderly than in the younger subset—however, in elders, eyelid malposition is often primarily associated with lid laxity (Weng et al, 2021). Lid laxity allows for corneal exposure and poor tear film spreading, inducing eye dryness. Other abnormalities in eyelid positioning in older patients include floppy eyelid syndrome, eyelid retraction, lagophthalmos, and entropion or ectropion.

Besides the age-associated decline in function of the specialized cells that produce the tear film, reduced tear production in patients over 60 years old can result in the increased use of topical medications (think glaucoma) and systemic drugs such as antidepressants, diuretics, dopaminergic drugs, and antimetabolites compounded by reduced drug clearance due to hepatic and renal decline (Mangoni and Jackson, 2004). Reduced corneal sensitivity, hormonal changes, systemic inflammatory conditions, and a higher prevalence of autoimmune diseases contribute to dry eye risk (Murphy et al, 2004). Interestingly, in older patients who have dry eye, goblet cells are more prone to stress apoptosis, resulting in reduced mucin production (Giebel et al, 2005).

Consider that this literature review highlighted features of dry eye that are age-linked. Thoughtful examination, diagnosis, and tailored management strategies apply to the young and older patients who have dry eye disease. CLS

REFERENCES:

1. Barabino S. Is dry eye disease the same in young and old patients? A narrative review of the literature. BMC Ophthalmol. 2022 Feb 22;22:85.
2. Talens-Estarelles C, Sanchis-Jurado V, Esteve-Taboada JJ, Pons ÁM, García-Lázaro S. How Do Different Digital Displays Affect the Ocular Surface? Optom Vis Sci. 2020 Dec;97(12):1070-1079.
3. Weng HY, Ho WT, Chiu CY, Tsai TY, Chang SW. Characteristics of tear film lipid layer in young dry eye patients. J Formos Med Assoc. 2021 Jul;120:1478-1484.
4. Sliney DH. How light reaches the eye and its components. Int J Toxicol. 2002 Nov-Dec;21(6):501-9.
5. Talens-Estarelles C, García-Marqués JV, Cervino A, García-Lázaro S. Use of digital displays and ocular surface alterations: A review. Ocul Surf. 2021 Jan;19:252-265.
6. Mangoni AA, Jackson SH. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. Br J Clin Pharmacol. 2004 Jan;57(1):6-14.
7. Murphy PJ, Patel S, Kong N, Ryder RE, Marshall J. Noninvasive assessment of corneal sensitivity in young and elderly diabetic and nondiabetic subjects. Invest Ophthalmol Vis Sci. 2004 Jun;45(6):1737-42.
8. The definition and classification of dry eye disease: report of the Definition and Classification Subcommittee of the International Dry Eye WorkShop (2007). Ocul Surf. 2007 Apr;5(2):75-92.
9. Giebel J, Woenckhaus C, Fabian M, Tost F. Age-related differential expression of apoptosis-related genes in conjunctival epithelial cells. Acta Ophthalmol Scand. 2005 Aug;83:471-476.