Therapies

Therapies roundup: Dry eye therapies

A primer on drugs commonly prescribed for patients with dry eyes.

BY MARK HAKIM, WORCESTER, MASS.

Dry eye syndrome is a condition characterized by a disturbance of the tear film. It is also referred to as dry eye or Keratoconjunctivitis sicca (KCS). Dry eye syndrome is subdivided into two types: aqueous deficient dry eye, caused by inadequate tear volume, and evaporative dry eye, caused by accelerated tear evaporation due to poor tear quality. Either can lead to ocular surface discomfort, often characterized by feelings of dryness, burning, a sandy or gritty sensation, itchiness or photophobia or some combination of these symptoms.

Several systemic conditions may be the underlying cause of the condition. A variety of medications may also be behind a dry eye diagnosis. For these patients, sometimes simply treating the systemic condition or switching them to an alternative medication may alleviate their problem.

Artificial tears

A variety of available treatment options are available for patients, depending on the severity of their symptoms (Table 1), however over-the-counter artificial tears are always a good starting point and may be sufficient for patients with milder disease. Preservative-free or non-irritating preservatives are available to those patients who are sensitive to preservatives or who require frequent dosing.

More viscous artificial tears coat the ocular surface longer, and artificial tears that contain polar lipids, such as glycerin, reduce evaporation. Artificial tear ointments applied before sleep are useful when patients have nocturnal lagophthalmos — the inability to close eyelids completely during sleep. These ointments are also helpful for patients with severe dry eye or with pain upon waking.

Physical treatment

Since the bulk of evaporative dry eye is due to meibomian gland dysfunction, patients should be instructed on proper lid hygiene technique. Warm compresses may be effective and lid scrubs may aide in decreasing bacterial flora or eradicating mites that inhabit the base of lashes (demodex folliculorum).

Goggles that apply heat may also be used to help liquefy the oils making them flow more readily through the glands.

Classes of therapy

Cyclosporine ophthalmic emulsion (Restasis, Allergan), is an immunosuppressant that treats an underlying cause of chronic dry eye. It is indicated to increase tear production in patients whose tear production is presumed to be suppressed to due inflammation associated with KCS.

Other patients may benefit from treatment with anti-inflammatory medications such as low-dose steroids, nonsteroidal agents, or combination antibiotic/anti-inflammatory medications to suppress an acute exacerbation of symptoms (Table 1).

For patients with moderate to severe dry eye, a hydroxypropyl cellulose insert (Lacrisert) can be placed in the pocket of the patient’s lower eyelid once or twice a day, to continually lubricate the eye and alleviate symptoms.

A few types of contact lenses (such as scleral contact lenses) can create a reservoir of fluid between the lens and the cornea to increase comfort by continually bathing the ocular surface in artificial tears. Scleral lenses not only improve patient comfort but also alleviate the impact of corneal irregularities induced by the dry eye condition, providing a much higher quality of vision. These lenses are particularly helpful in patients with systemic conditions, such as Sjogren’s Syndrome, limbal stem cell deficiency that may occur from chemical burns, rheumatoid arthritis, and graft versus host disease. Such patients often have extremely irregular ocular surfaces due to scarring and extreme forms of dry eye syndrome. For milder forms of dry eye, low water content HEMA lenses may improve comfort. Silicone rubber lenses that contain no water, readily transmit oxygen may also be a consideration.

Interventional treatments include

• Punctal occlusion: The insertion of punctal plugs (made of collagen or silicone) into the inferior or superior puncta helps retain tears (or medications) on the ocular surface for a longer time. Temporary (dissolvable) plugs may be placed as a trial and replaced with permanent plugs if the patient’s symptoms improve.

• Cauterization: can be done by permanently closing the lacrimal punctum if plugs were effective.

• Tarsorrhaphy: For use in severe cases in which there is an anatomic issue with the lids resulting in incomplete or weakened closure. The eyelids are partially sewn together to reduce the size of the palpebral aperture and reduce tear loss through evaporation.

• Lipiflow: Lipiflow (TearScience) is a thermal pulsation system that milks the oils from the meibomian glands during a 13-minute treatment.

• Antibiotics: Oral antibiotics such as doxycycline or tetracycline may control associated blepharitis or dry eye conditions associated with inflammatory meibomian gland dysfunction. These medications are particularly effective in patients with rosacea blepharitis, however they may be associated with side effects, and should be avoided in patients with gastrointestinal ailments. OP

This article has been reviewed by Kendall E. Donaldson, MD, MS. Dr. Donaldson practices at Bascom Palmer Eye Institute in Miami, Fla.

Mark Hakim is a student at the Massachusetts College of Pharmacy and Health Sciences University School of Optometry, Worcester, Mass.