dry eye causes
Minimizing the Causes of Dry Eye
Discussing these factors with patients can help prevent severe dry eye.
KATHERINE MASTROTA, O.D., M.S., F.A.A.O. Brooklyn, N.Y.
Address hydration and proper nutrition with patients who may be presenting with early symptoms of dry eye.
Every machine, including the human body, needs routine maintenance, protection from harmful elements and minimization of external stressors. Think of the ocular surface as an exquisitely balanced “machine.”
Prevention and early recognition/intervention of the signs and symptoms of ocular surface stress maximizes ocular surface performance. Daily “kindnesses” to the ocular surface system yield the fruit of ocular comfort, improved vision, contact lens success and superior surgical visual outcomes.
What can we do to be kind? There are many issues you can address with patients who may be presenting with the early symptoms of dry eye, which I will discuss in this article.
Inside and out
My number one patient question to identify early ocular surface compromise is “Do you feel your eyes?” The query is akin to asking, “Do you feel yourself breathing?” Any response that even approaches affirmation to the question is a signal to me that there is a concern for the ocular surface and change is in order to keep future difficulties at bay. Examples include acknowledging earlier-than-customary contact lens removal, contact lens awareness and recognizing the urge to blink.
Once you have identified the early symptoms of dry eye, discuss the following factors with your patients:
► Adequate bodily hydration. If we are suffering from dehydration, so will our ocular surface. Individuals classified as DE have higher plasma (blood) osmolarity, indicating suboptimal hydration, compared with non-dry eye patients. I recommend patients to be mindful of their fluid consumption and suggest increasing (appropriately) if it seems inadequate. Drinking (water, sparkling or still preferred) when thirsty and adding a glass or two of water a day to their habitual fluid consumption should be an easily obtainable goal.
► Proper nutrition. Busy lifestyles tend to go hand-in-hand with a diet designed for quick-and-easy consumption. My patient medical history includes a query regarding the patient’s diet. Most patients are aware of where their diet is lacking proper balance. Fast foods, snack foods and packaged preserved food products are notorious for unbalanced nutrition, lacking particularly in omega-3 fatty acids. Many commercially available omega-3 supplements are available to address this deficiency. Additionally, I suggest that patients consult with their primary care provider or nutritionist to devise a food plan appropriate for the patient’s age, health and weight.
► Substituting for medications. Many oral medications (e.g., antihistamines, anti-hypertensives, anti-depressants and diuretics) have the adverse side effect of causing dry eye. Reducing reliance on these products via lifestyle modification promotes better overall health and ocular health. Some examples: managing incontinence with planned elimination and drinking carefully selected beverages; counteracting stress with exercise, massage and yoga; lowering blood pressure through diet modification and weight loss; addressing allergy via environmental modification and local vs. systemic treatment of symptoms.
► Allergy. The signs and symptoms of allergy can be obvious or subtle. Certainly, red, chemotic and itchy eyes are pathognomonic for allergy. Subtle allergy can be teased out through careful questioning of patient symptoms, such as a history of rhinitis, sinusitis, post-nasal drip or asthma. Recommend local topical eye treatment in conjunction with “allergy-proofing” the patient’s surroundings (pillow covers, air filters, removing carpeting, etc.).
► Lid hygiene. Bacteria, allergens, makeup and environmental debris and Demodex mites settle on/embed in the lid margin and lash follicles causing focal irritation and inflammation. I suggest gentle cleansing with commercially prepared products to remove accumulated debris from the lid and lash margin. Chronic disruption of the homeostasis of the lid margin contributes to anterior and posterior blepharitis that, in the long-term, can contribute to or cause dry eye.
Additionally, a recent study notes that increased sensitivity of the lower lid margin was associated with hyperosmolarity of the tear film, suggesting a nerve ending response to pro-inflammatory cytokines present in hyperosmolar tears. Intuitively, the washing away some of these inflammatory mediators could protect the lid margin from discomfort and adverse changes related to dry eye.1
Here, anterior segment imaging is useful in increasing patient compliance. Generally, after patients have seen a magnified view of the debris on their eyelid margin and eyelashes, they have an increased understanding of why lid hygiene is important.
► Contact lens compliance. Contact lens overwear, overextended lens replacement schedules, solution sensitivity and improper cleaning and storage of lenses can challenge the ocular surface, resulting in reduced corneal sensation and subsequent dampened tear production. Meticulous patient instructions, education and follow-up help safeguard against contact-lens related infectious, inflammatory and dry eye episodes. Provide the patient printed materials regarding proper hand washing and drying prior to lens handling, timely lens and lens case replacement, keeping to prescribed lens solutions and the associated risks of non-compliance.
► Smoking cessation. Multiple studies suggest that cigarette smoking/cigarette smoke poses a significant challenge to the homeostasis of the ocular surface. A 3,722-subject cohort study shows a nearly two-fold increase in the odds for dry eye among smokers. Furthermore, studies show that smokers have a reduced tear film breakup time and reduced basal tear secretion.2,3
Similarly, smoking effects tear film lipid quality and spread. Conjunctival impression cytology in habit smokers reveals a significant loss of goblet cells and squamous metaplasia.4 So important is the impact of smoking that it is incorporated into the Meaningful Use Objectives in Electric Health Records. A discussion on smoking cessation and eye health should be a priority in each case disposition. Even second hand smoke can have adverse effects on the ocular surface and should be avoided.5
► Botulinum toxin (BOTOX) injections. The injection of BOTOX decreases the appearance of wrinkles, primarily between the eyebrows and around the eye, through temporary chemical denervation of the muscles that cause the wrinkles to develop. Several case studies show dry eye as an adverse side effect from the use of BOTOX for cosmetic and medical purposes, such as blepharospasm. This is due to the local diffusion to structures adjacent to the injection site.6-10 Besides decreased tear production, it has been proposed that botulinum neurotoxin chemodenervation of the orbicularis oculi muscle leads to a poor blink mechanism, lagophthalmos and ectropion that may result in corneal dryness.11 Patients receiving BOTOX injection should be fastidiously monitored for any abnormalities of the blink, eyelid tone or malposition. Discuss reduced, delayed or limited units of BOTOX, should eye comfort complaints ensue.
► Drafty, dry environment. Dry heat, controlled air environments (airplanes, hotel, hospitals, etc.), window or floor fans, overhead fans, air conditioners, space heaters and open car windows all move air across the cornea, promoting ocular surface desiccation. When appropriate, through time, the addition of humidity to the air via humidifiers and reduction of drafts may postpone the development of symptomatic dry eye.
► Cyclosporine. FDA-approved for ocular administration, cyclosporine ophthalmic emulsion 0.05% (Restasis, Allergan) is indicated to increase tear production in patients whose tear production is presumed to be suppressed due to ocular inflammation associated with keratoconjunctivitis sicca. Topical cyclosporine use also increases goblet cell density, suggesting better conjunctival mucin production.12
My personal experience leads me to believe that initiating cyclosporine therapy earlier rather than later in the course of suspected ocular surface changes yields better subjective results. Consider adding cyclosporine, even when subtle surface-related complaints arise.
► Glaucoma medications. Chronic administration of topical glaucoma medications have adverse effects of creating tear film instability, conjunctival epithelium changes and corneal surface impairment. Instruct patients to consider laser therapy (e.g. selective laser trabeculoplasty, iridotomy, peripheral iridoplasty) as a primary or adjunct therapy to lower intraocular pressure to avoid or lessen the need for these topical agents.13
These small, yet important changes outlined above may be instrumental in delaying or preventing negative changes in ocular surface. Systematically addressing the multitude of insults to the ocular surface, and being kind to it, will enable you to reap the rewards of patient satisfaction, as they maintain visual comfort and confidence in your care. OM
1. Golebiowski B, Chim K, So J, Jalbert I. Lid margins: sensitivity, staining, meibomian gland dysfunction, and symptoms. Optom Vis Sci. 2012 Oct;89(10):e1443-9.
2. Thomas J, Jacob GP, Abraham L, Noushad B. The effect of smoking on the ocular surface and the precorneal tear film. Australas Med J. 2012;5(4):221-6. Epub 2012 Apr 30.
3. Yoon KC, Song BY, Seo MS. Effects of smoking on tear film and ocular surface. Korean J Ophthalmol. 2005 Mar;19(1):18-22.
4. Matsumoto Y, Dogru M, Goto E, Sasaki Y, Inoue H, Saito I, Shimazaki J, Tsubota K. Alterations of the tear film and ocular surface health in chronic smokers. Eye (Lond). 2008 Jul;22(7):961-8. Epub 2008 Apr 18.
5. Ward SK, Dogru M, Wakamatsu T, Ibrahim O, Matsumoto Y, Kojima T, Sato EA, Ogawa J, Schnider C, Negishi K, Tsubota K. Passive cigarette smoke exposure and soft contact lens wear. Optom Vis Sci. 2010 May;87(5):367-72.
6. Coroneo MT, Rosenberg ML, Cheung LM. Ocular effects of cosmetic products and procedures. Ocul Surf. 2006 Apr;4(2):94-102.
7. Northington ME, Huang CC. Dry eyes and superficial punctate keratitis: a complication of treatment of glabelar dynamic rhytides with botulinum exotoxin A. Dermatol Surg. 2004 Dec;30(12 Pt 2):1515-7.
8. Arat YO, Yen MT. Effect of botulinum toxin type a on tear production after treatment of lateral canthal rhytids. Ophthal Plast Reconstr Surg. 2007 Jan-Feb;23(1):22-4.
9. Mack WP. Complications in periocular rejuvenation. Facial Plast Surg Clin North Am. 2010 Aug;18(3):435-56.
10. Klein AW. Complications and adverse reactions with the use of botulinum toxin. Dis Mon. 2002 May;48(5): 336-56.
11. Ozgur OK, Murariu D, Parsa AA, Parsa FD. Dry eye syndrome due to botulinum toxin type-A injection: guideline for prevention. Hawaii J Med Public Health. 2012 May;71(5):120-3.
12. http://www.restasisprofessional. com/Restasis_Information_Increasing_Te ar_Production.cfm Accessed 10/15/2012
13. Servat JJ, Bernardino CR. Effects of common topical antiglaucoma medications on the ocular surface, eyelids and periorbital tissue. Drugs Aging. 2011 Apr 1;28(4):267-82.
Dr. Mastrota is secretary of the Ocular Surface Society of Optometry. She is center director at the New York office of Omni Eye Services and a consultant to Allergan, Bausch + Lomb, Merck, Noble Vision and Ocusoft. Email her at firstname.lastname@example.org, or send comments to optometricman email@example.com.