Dry Eye and Blepharospasm

The term "Dry Eye" refers to a group of diseases which cause symptoms of grittiness or foreign body sensation, burning and dryness. These diseases can be divided into two general categories: those diseases in which tear secretion is inadequate or decreased and those in which tear secretion is adequate or normal. The term "keratoconjunctivitis sicca (KCS)" is used to describe those conditions in which tear secretion is decreased. The most common cause of KCS is Sjogren's syndrome, which is characterized by dry eyes, dry mouth and a systemic autoimmune disease. In secondary Sjogren's syndrome, there is a definable systemic disease such as rheumatoid arthritis, systemic lupus or scleroderma. In primary Sjogren's syndrome, there is no definable systemic disease. Other causes of keratoconjunctivitis sicca include graft vs. host disease seen following bone marrow transplantation, AIDS and lymphoma involving the lacrimal glands.

Dry eyes associated with normal tear secretion are quite common. The term "Dry Eye" and normal tearing or tear secretion may seem paradoxical. However, dry eye can be caused by conditions other than those which cause decreased tear secretion. It is helpful to consider the physiology and structure of the lacrimal gland and tear film. At the present time, the tear film is thought to be composed of three layers. The outer layer is called the oily or lipid layer and is secreted by meibomian glands which are tiny glands along the eyelid margins just behind the eyelashes. With blinking, the oil in these glands is expressed onto the surface of the tear film where it acts as a barrier to impede penetration of environmental pollutants into the tear film, as well as prevent evaporation. The middle layer, the aqueous layer, is secreted by the main and accessory lacrimal glands. This layer forms the majority of the tear film and contains numerous substances which are necessary for the health of the surface of the eye. These include substances which prevent infection, and are necessary for normal growth and maintenance of the surface. The inner most layer is the mucin layer. It is secreted by goblet cells which are on the surface of the eye. The mucin provides a protective barrier for the surface and serves as a means for the aqueous layer to adhere to the surface of the eye. Conditions which affect the lipid layer or the mucin layer can also cause a dry eye.

The most common cause of dry eye with normal tear secretion is blepharitis (bleph - eyelid; itis - inflammation). Blepharitis can be associated with skin diseases such as seborrhea or rosacea or can occur by itself. In this condition there is either a lack of oily secretion or an abnormality of the oil which leads to inadequate coverage of the aqueous layer, or both. This results in increased evaporation of tears, as well as an increased ability of environmental pollutants to contaminate the tear film.

Conditions which reduce or result in loss of the mucin layer are fortunately uncommon. These involve inflammatory conditions due to diseases such as ocular pemphigoid, Stevens-Johnson syndrome, chemical injuries or Vitamin A deficiency.

Dry eye conditions can be uncomfortable enough to cause blepharospasm. The eye irritation causes increased blinking and involuntary forced closure of the eyelids. However, blepharospasm can also cause dry eye symptoms. This results from the squeezing and forced eyelid closure which can cause symptoms similar to, but not identical to, other forms of dry eye. The exact reason why patients with blepharospasm experience dry eye complaints is not known, but it is suspected that it is related to forced eyelid closure and increased blinking.

Patients with blepharospasm tend to have different symptoms than those with other forms of dry eye. These patients often complain of an uncomfortable dry feeling in the eye that they find difficult to describe. Burning may be present, but the feeling of grittiness or sand or gravel in the eye is usually not present. In addition, when the patient with blepharospasm is examined, there are usually no abnormalities of the eyelids or surface of the eye and tear secretion is usually normal.

When a patient first sees me for complaints of a dry eye, I question the patient quite carefully as to their symptoms, when they occur, and how severe they are. I also ask them if they have noticed that they blink a lot, or have difficulty holding their eyelids open or opening their eyes after they blink. Family members are also asked if they have observed any increased blinking or spontaneous lid closure in the patient. I then examine the eyes for evidence of dryness. This includes a careful detailed examination under magnification of the eyelids and the surface of the eye. A small piece of paper is placed in each eye (Schirmer test) to measure the amount of tear secretion. Several different dyes, such as fluorescein, rose bengal and lissamine green are placed in the eye to determine if there are any abnormalities of the surface, which are seen as tiny dots of stain on the eye surface.

Often the patient with blepharospasm is told, that either there is nothing wrong or that he or she has dry eyes. This is because the eye examination fails to show any significant abnormalities. Occasionally a mild blepharitis is present. With longstanding blepharospasm, the skin of the upper eyelid may be redundant or baggy (called dermatochalasis). The upper eyelids may droop (called ptosis). Other than these findings, the eye exam is indeed often normal.

I will usually treat the patient with blepharospasm as I would a dry eye patient to see if symptoms will improve. The usual treatment includes topical unpreserved artificial tears every two hours, warm compresses to the eyelids twice a day and ointment placed in the eyes at bedtime. A patient with dry eyes due to aqueous tear secretion or blepharitis will almost always show some improvement with this treatment. However, the patient with blepharospasm will usually not improve. I like to use this treatment regimen as a diagnostic test. Absence of improvement suggests that blepharospasm may be causing the patient's symptoms. Therefore, I suspect blepharospasm in the patient who presents with symptoms that are not typical for other forms of dry eye, who has a normal clinical exam with normal tear secretion, and who has no evidence of staining of the surface of the eye and no response to the usual treatment for dry eye.

Patients with blepharospasm will usually respond to Botox injections (Allergan, Irvine, CA). Relief of the eyelid spasm greatly improves symptoms. Occasionally, following Botox, patients will experience new symptoms of dry eye that can be attributed to inability to close the eyelids (lagophthalmos) or an underlying mild dry eye condition. These normally respond to the typical treatment for dry eye.

In summary, patients with blepharospasm often have dry eye complaints. These complaints can precede the onset of severe blepharospasm symptoms. These symptoms however, are not typical for KCS. In addition, clinical exam often shows no evidence of a typical dry eye condition. Finally, patients with blepharospasm do not usually respond to routine dry eye treatment with artificial tears, ointments and warm compresses. The use of Botox is of great importance in treating patients with blepharospasm. Should the patient become refractory to Botox, surgery to remove some of the muscle (orbicularis) in the eyelids is often helpful.

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