Dry Eyes – Diagnosis, Symptoms, and Treatment

What are Dry Eyes?

Dry eye is a disorder 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), a “gritty” feeling, burning, foreign body sensation, and brief periods of increased tear production.  Dye eyes 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 destruction of the tear and oil glands that lubricate the eyes.  Risk factors for dry eyes include older age, female gender, hyperandrogenism, and contact lens use.

Dry eye can significantly impair visual acuity, the performance of daily activities, and physical and occupational function.  Your doctor will normally refer you to an optometrist or 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 signs 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
• Hyperandrogenism 
• Systemic conditions (e.g. diabetes)
• Contact lens use
• Medications (e.g. antihistamines, anticholinergics)
• Vitamin A deficiency
• Eye surgery
• Low humidity 
• Sjögren syndrome - a chronic inflammatory disorder characterized by reduced tear gland function

How Common are Dry Eyes?

Dry eyes are estimated to affect 15% of the US population, with it being more common in women and those above 50 years of age. The true number of people with dry eyes is likely higher as some individuals are able to self treat with allergy medications and unmediated eye drops. Individuals with severe and disabling systems are rare as the majority of cases, while irritating and uncomfortable, are categorized as mild. 

Signs and Symptoms

Dry eyes most commonly present with redness and a vague sense of discomfort that is often described as the eyes feeling tired, dry, or scratchy. In more severe cases changes in vision may result. 

The most common signs and symptoms include:

• Dryness
• Injection (red eyes)
• Irritation or gritty feeling
• Burning 
• Foreign body sensation
• Increased tear production
• Sensitivity to light 
• Blurred vision

Visual changes are often temporary and improve with treatment.  On rare occasions, patients may develop corneal scarring, which can result in permanent visual loss.  These severe symptoms are more common in individuals with Sjögren syndrome who also normally experience dryness of the mouth.

Diagnosis

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 is 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 the discontinuation of offending medications such as antihistamines and tricyclic antidepressants.  Psychotropic medications that affect mental health are generally tapered 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 and workplace 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. These are prescription medications that are different than the normal water-based eye drops obtained over the counter. 

Depending on the cause of your dry eyes your physician may recommend corticosteroid eye drops that reduce inflammation. In the case of autoimmune conditions such as Sjögren syndrome may benefit from medications that reduce the activity of the immune system. Some of the most common are:

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.

References:

1. 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
2. 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
3. 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