Dry eyes implies that we are not making enough tears and that the surface of the eye is drying out. Our tear film is actually made up of several components, the oily layer, the watery layer, and the mucopolysaccharide layer. Artificial tears are best at replenishing the water layer. This will help many but not all patients. In some cases, it is the oil layer, which is deficient.
This can be supplemented by taking fish oil tablets in the amount of 2 to 4 g per day. The oil layer is produced predominantly by glands in the upper and lower eyelids. When these glands are inflamed, people will often notice redness at the rims of their eyelids. In addition to taking fish oil tablets, hot compresses can often help the oil glands to clean themselves and provide increased oil secretions to the surface of the eye thereby improving dry eyes. The dysfunction of the oil glands is also known as Meibomian Gland Dysfunction. (MGD)
We actually have two systems of tear production. The basal secretion, which is akin to drip irrigation in the garden, is due to a series of very small tear glands on the surface of the eyes. When this layer is insufficient, patients will often develop low-grade irritation from wind or cold that can trigger “the emergency sprinkler system” from the large lacrimal gland, which is located under the upper outer bone of the eye socket. When this system kicks on, the patients will often complain of watering. Therefore, patients with mild dry eyes may actually have watering as their primary symptom. This is known as reflex tearing. Using artificial tears 4 to 6 times per day will often reduce the symptoms.
When patients have significant symptoms from dry eyes that are not relieved with the use of artificial tears 2 to 4 times per day, we have two additional modalities that are often helpful. The first is to place plugs or surgically occlude the lacrimal puncta on the lower eyelids. These are the small openings in the eyelids toward the nose. These catch tears and channel them away from the eye into the nose. This is where tears normally drain.
Careful examination by an ophthalmologist can determine whether the eyes are dry enough to merit occlusion of the lower puncta. Occlusion of both the upper and lower puncta is rarely done but can be appropriate for the patients with extremely severe dry eyes (Sjogren’s syndrome). The puncta are occluded in one of two ways. The placement of a silicon rubber plug in the punctum is quite effective but this will occasionally cause irritation. In many cases, Dr. Yohai prefers to first place a temporary collagen plug within the punctum so it is not sticking up and irritating the eye. This serves as a temporary test to determine whether blocking the punctum will cause excess tearing. If no excess tearing is encountered with the temporary plugs then the puncta are gently cauterized under local anesthesia to create a mild burn, which results in the puncta scarring gently shut. The danger of doing this is that the cautery occlusion is sometimes irreversible.
The advantage is that it is truly permanent, does not fall out, and does not cause irritation, whereas permanent punctal plugs can fall out and can cause irritation. There is a type of punctal plug which goes down below the punctum into what is called the canaliculus, the thin tube that joins the punctum to the tear duct that goes into the nose. Dr. Yohai strongly discourages the use of intracanalicular punctal plugs as he has seen many instances in which these scar in place can cause permanent blockage and subsequent symptoms.
Restasis: Restasis is a medication which reduces the amount of the immune cells in the eyelids. Therefore, it is essentially a type of mild anti-inflammatory medicine. It has been shown that reducing the inflammation of the surface of the eye in this manner can lead to an increase in tear production. The response to Restasis can be quite dramatic in some patients but virtually none in others. The decision as to whether to proceed with Restasis versus punctal occlusion must be made by the patient. For those who are willing to put a prescription medicine in their eyes twice per day on an ongoing basis may prefer Restasis. Others who would like a quicker improvement may prefer punctal occlusion. Often both modalities are used.