What are Dry Eyes?
Dry eye is a disease of the tears and eye surface that leads to eye discomfort and impaired vision. The medical term for dry eye is keratoconjunctivitis sicca. The most common symptoms and signs of dry eye often include dryness, injection (red eyes), irritation or gritty feeling, burning, foreign body sensation, and increased tear production. The condition may be caused by medications such as antihistamines or tricyclic antidepressants. It may also be caused by Sjögren syndrome, a rare chronic inflammatory disorder characterized by reduced tear gland function. Risk factors for the condition include older age, female gender, hyperandrogenism, and contact lens use.
Dry eye can significantly impair visual acuity, performance of daily activities, and physical and occupational function. Your doctor will normally refer you to an ophthalmologist for specific testing.
What Causes Dry Eyes?
Dry eye is caused by a complex interplay of multiple factors. Problems with the tear gland, eyelids, or eye surface can lead to the condition. Two general categories of the disease include individuals with reduced tear production and those with increased tear evaporation. Either of these conditions can lead to dehydration and inflammation of the eye surface, which results in the symptoms and sigs of the condition.
There are a variety of factors or conditions that increase one’s risk of developing dry eye, such as:
- Older age
- Female gender
- Systemic conditions (e.g., diabetes)
- Contact lens use
- Medications (e.g., antihistamines, anticholinergics)
- Vitamin A deficiency
- Eye surgery
- Low humidity
- Sjögren syndrome - chronic inflammatory disorder characterized by reduced tear gland function
How Common are Dry Eyes?
It is common in the United States and is often initially evaluated in the primary care clinic. The condition usually requires referral to an ophthalmology specialist, particularly if first-line and conservative measures have been unsuccessful.
The prevalence of dry eye is approximately 15% overall. About 18% of women and 11% of men have the condition. Some studies show a prevalence of 5%-30% in individuals age >50. The prevalence of dry eye is anticipated to rise as the population ages.
Signs and Symptoms
The most common symptoms and signs include:
- Injection (red eyes)
- Irritation or gritty feeling
- Foreign body sensation
- Increased tear production
- Sensitivity to light
- Blurred vision
Symptoms of blurred vision are often temporary and improve with treatment. In rare occasions, patients may develop corneal scarring, which can result in permanent visual loss. Individuals with Sjögren syndrome also normally experience dryness of the mouth and poor dental hygiene.
Dry eye is diagnosed based on symptoms and physical examination findings – there is no specific test for the disease. Your doctor will typically check your visual acuity with a Snellen eye chart. They will also check your pupillary light reflexes, visuals fields, and perform a funduscopic examination. In addition, your doctor will evaluate for the following findings on examination:
- Bilaterally symmetric red eyes
- Paradoxical excessive tearing
- Inflammation of the eyelids (blepharitis)
- Malpositioned eyelids
- Reduced blink rate – this can be a sign of Parkinson disease
Your doctor will usually refer you to an ophthalmologist for a slit lamp evaluation and additional testing. One commonly performed test is the Schirmer test. During this study, a small strip of filter paper is placed in the lower eyelid of both eyes. The number of tears produced are measured in millimeters and collected over 5 minutes. Low tear production is highly suggestive of the disease.
Dry Eyes Medication and Treatment
The first step in treatment is discontinuation of offending medications such as antihistamines and tricyclic antidepressants. Psychotropic medications are generally tapered slowly off slowly if possible. Additionally, patients may benefit from environmental strategies such as frequent blinking and minimization of exposure to air conditioning or heating. Bedroom office humidifiers can also be beneficial.
Artificial tears are also an important component of dry eye treatment. They contain cellulose, a spreading agent (e.g., polyethylene glycol or polyvinyl alcohol), and a preservative. Artificial tears are available in liquid, gel, and ointment formulations.
Restasis (0.05% emulsion of cyclosporine) is a topical immunosuppressive medication that takes up to 6 weeks to improve symptoms. Xiidra (topical lifitegrast 5.0%) is an integrin antagonist used twice a day in patients with refractory symptoms.
- 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; 5:75. - https://www.tearfilm.org/dewsreport/pdfs/TOS-0502-DEWS-noAds.pdf
- Perry HD, Solomon R, Donnenfeld ED, et al. Evaluation of topical cyclosporine for the treatment of dry eye disease. Arch Ophthalmol 2008; 126:1046. - https://jamanetwork.com/journals/jamaophthalmology/fullarticle/420693
- Ezuddin NS, Alawa KA, Galor A. Therapeutic Strategies to Treat Dry Eye in an Aging Population. Drugs Aging 2015; 32:505. - https://www.ncbi.nlm.nih.gov/pubmed/26123947
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.