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	Dry Eyes and its Effects on Contact Lens Wear by Alvaro Cordova, LDO, ABOC-AC / NCLEC

Introduction

Contact lens wear requires certain conditions to be in place for a fit to become successful. Dry eye syndrome, or formally keratoconjunctivitis sicca, is a term for a group of symptoms whose etiology range from genetics to environmental. This paper will discuss lipid abnormalities, aqueous tear deficiencies, and mucin deficiency. These abnormalities cause several obstacles to a proper fit. While patients may complain of ocular symptoms such as burning or irritation, keratoconjunctivitis sicca poses more of a problem than just discomfort.

Classifying keratoconjunctivitis sicca will vary. As mentioned by Buddy Russell FCLSA, keratoconjunctivitis sicca has been divided by some researchers into five categories, the three listed above and two of which will not be covered in any significant detail in this paper: lid surface abnormalities and epitheliopathies. Others, such as C. Stephen Foster M.D. divide keratoconjunctivitis sicca into two categories, Sjogren’s syndrome (SS) related or non Sjogren’s syndrome (non-SS) related. The former approach is based on ocular anatomy. The latter basing itself on systemic etiology.

The Tear Film

Before any discussion of keratoconjunctivitis sicca can take place, it is important to know what the tear film is and how it functions. The tear film is composed of three layers: lipid, aqueous and mucin. Each of these layers has an important function in keeping the eye lubricated, clear and comfortable.

Tears provide the eye with a lubricating surface between the globe and lids. They also provide oxygen to the cornea. This is of particular importance since many eye conditions are associated with corneal hypoxia due to contact lens abuse. Antibacterial substances in the tears provide the eye with an initial layer of protection against microbes. The tears give the cornea a very smooth refractive surface by filling in spaces on the cornea on the microscopic level and provide hydration to the eye surface. Tears trap and remove debris such as epithelial cells that shed regularly.

The lipid layer is comprised of oils secreted by the meibomian glands. Some oils are also produced by the gland of Zeis. Both glands are located on the eyelids. It is common knowledge that oil floats on water. Similarly, the lipid layer acts like the oil on the aqueous layer decreasing the rate of evaporation.

Keratoconjunctivitis Sicca

Keratoconjunctivitis Sicca (KCS) is a surface inflammation of the cornea and conjunctiva due to dryness. It may also be referred to as Keratitis Sicca. KCS is caused by a decrease in tear production or a compromise in one of the layers of the tear film, the etiology of which will be discussed. Patients may complain of a variety of symptoms such as burning, irritation and dryness. Other descriptions include “scratchy” or “tired” eyes. A counter-intuitive symptom may be excessively watery eyes. As a result of dryness in the eyes, the body may react by over-producing more tears. The severest cases can include corneal scarring and corneal perforation. Contact lens wear may become interrupted intermittently or for continuous periods of time.

Aqueous Tear Deficiency

Aqueous tear deficiency is the most common problem affecting the tear film. Several conditions may be responsible for decreased or abnormal tear production. As a health care provider, your awareness becomes crucial in assisting the patient to the proper course of action.

Sjogren’s Syndrome

Sjogren’s syndrome is a chronic auto-immune disease that may affect any organ. Depending on the study, prevalence can be as low 0.5% of the population or between 3% to 5%. Sjogren’s syndrome has been observed to manifest alone or in conjunction with other auto-immune diseases. Women are affected at a much higher rate than men by a ratio of nine women to every man. Sjogren’s syndrome has been found to most occur around the ages of forty through late fifties. Symptoms may include dry mouth and dry eyes as well as fatigue. It is not uncommon for Sjogren’s to cause dryness of the skin and other organs. Some auto-immune diseases that may accompany Sjogren’s syndrome are rheumatoid arthritis, lupus, scleroderma and others.

Sarcoidosis

Sarcoidosis is an inflammatory disorder of unknown origin. The disease also goes by Besnier-Boeck disease or Boeck’s sarcoid. The disease manifests as non-caseating microscopic granulomas, or nodules, throughout various tissues of the body, but mainly in the lungs. Caseation is necrosis that has a characteristic cheese-like appearance under the microscope. In the case of sarcoidosis, there is a low amount of necrosis as opposed to necrosis found in other granulomatous conditions such as tuberculosis. Sarcoidosis generally affects young adults and women.

Symptoms include fatigue, weight loss, pain, and shortness of breath. Ocular symptoms may include uveitis and KCS. KCS symptoms may develop through either a deformity that interferes with normal blinking or lesions on the conjunctiva. In some cases, the lacrimal gland may become inflamed and interfere with normal tear production.

Aging

Aging itself is not a disease and our bodies are not pre-programmed to age necessarily. Many theories about the aging process exist. Anyone who is significantly older than you will not hesitate to advise you to “not grow old.” While this is not a possibility, understanding the aging process will help in understanding what the patient may experience as they grow older. This is especially true today as the baby boomers are coming to retirement age and may develop dry eye symptoms.

Aging is associated with decreased tear production. Both quantity and quality may be affected. As one gets older, muscles in the body and eyelid become weaker. Older patients may develop an ectropian, a lid that turns outward, or a ptosis, a drooping eye lid. A patient who has an ectropian will have a pool of tears accumulating on the lower lid. While this falls under a lid abnormality, aqueous tear deficiency, coupled with an ineffective blink may expose the cornea to infection.

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease. There is no known cause, but infection is speculated as well as a possible genetic component. Other known factors include stress, hormones, and immune response. Frequency among the population is about 1%. Native Americans show more predisposition to RA than other races. RA is also 2 to 3 times more common in women than in men.

Arthritis is a condition that causes joint pain. In RA, patients may complain of swelling in joints that is typically symmetric. Ocular manifestations include scleritis, episcleritis and dry eyes. As mentioned before, Sjogren's syndrome may be found in patients suffering from RA, but not necessarily so.

Medications

There are medications that may cause some of the symptoms of KCS by decreasing lacrimation. Whether over-the-counter or by prescription, it is important for the patient to divulge all medications to their health care provider to rule out medication as a possible cause of KCS. Many drugs such as anti-histamines and pain-killers are ubiquitous and can often be overlooked by the patient since many are over-the-counter. Other drugs that may cause a decrease in the amount of tears produced includes tranquilizers, contraceptives, anti-cholinergic drugs, diuretics and anti-hypertensive medication to name a few. Contact lens wear may be complicated by the dry eye side effects of these medications.

Lipid Deficiency

Several diseases and conditions can cause a lipid abnormality. As mentioned, the meibomian glands are responsible for producing oils that prevent the evaporation of tears.

Blepharitis

Blepharitis is the most common lid disorder. Blepharitis is an acute or chronic inflammation of the eyelids, chronic being the most common. The inflammation may be caused by the presence of a bacterial infection. Blepharitis can lead to complications such as lid notching, chalazion, trichiasis, conjunctivitis, punctate keratitis and even corneal ulceration.

Blepharitis can be classified into two types: Anterior marginal blepharitis and posterior marginal blepharitis. Symptoms include the crusting and thickening of the lid margins with crusting and scaling along the bases of the lashes. Other symptoms include itching, excessive watery eyes, burning, foreign body sensation/grittiness. Generally, symptoms are similar for both types, but posterior blepharitis is considered more difficult to diagnose because symptoms may not be as evident.

Meibomianitis

Meibomianitis (also known as meibomitis) is a chronic inflammatory dysfunction of the meibomian glands. One of the most prominent symptoms is a white froth like presence located at the lid margins. Another sign is “globules” of oils secreted by the meibomian glands present at each gland duct. It is common for meibomianitis to be associated with posterior marginal blepharitis, but can also be found on its own.

Mucin Deficiency

Stevens-Johnson Syndrome

Stevens-Johnson syndrome (SJS) is a milder form of a disease called toxic epidermal necrolysis (TEN). Previously, the disease was thought to be a severe form of erythema multiforme (EM), although there is ongoing debate about this. Current reasoning has shifted because both SJS and TEN both have the same signs, treatment, and prognosis. Regardless of the classification, SJS affects the mucous membranes by erupting in blisters. Lesions on the conjunctiva are a common sign of those suffering from SJS. Causes vary from drugs, infection, systemic disease and even food, but most commonly drugs. If left untreated, ocular defects may become present such as trichiasis and entropian.

Complications of Contact Lens Wear

Corneal neovascularization (NV) is a serious complication of contact lens wear. NV of the cornea are vessels that grow into the cornea. Current thinking suggests that vessels deeper into the cornea are a result of less oxygen to the cornea then that of superficial vessels. Keeping the cornea avascular is extremely important. If enough vascularization occurs, contact lens use may need to be discontinued entirely. With the introduction of silicone hydrogels with high Dk values, contact lens users have decreased the incidence of corneal NV. NV can also be exacerbated by non-compliance and over-wear of contact lenses. Contact lens wearers who also have KCS are at an increased risk of neovascularization. The eye care professional would need to address any dry eye conditions before continuing contact lens wear.

Treatments and Options

Punctal plugs, as the name suggests, interfere with the drainage of tears through the puncta. Punctal plugs are a consideration if artificial tears do not treat symptoms. There are also new prescription drugs that may also be used; Restasis and FreshKote. FreshKote attempts to treat each layer of the tear film and increase its stability. Restasis helps by increasing tear production. Depending on the severity and etiology, KCS may necessitate surgery such as Tarsorrhaphy.

Conclusion

Contact lens wear paired with KCS may cause complications. As many eye-care professionals know there are many patients who are not compliant. Many people tend to ignore symptoms until it's generally very serious. While some treatments help, for many the condition is chronic, depending on the etiology. Thankfully, with monitoring and treatment there is some reprieve for many of the severest cases. With some care, patients can still wear contacts and manage symptoms as they arise.