Coordinated by Bobby Christensen, O.D., F.A.A.O.

therapeutic insights
What to do About Dry Eye
Punctal occlusion is still a reasonable treatment for dry eyes.
By Stuart A. Gindoff, O.D., M.B.A., F.A.A.O., Sarasota, Fla.

Dry Eye Syndrome (DES), also known as keratoconjunctivitis sicca, is probably one of the most common ocular surface diseases that an eyecare practitioner sees in day-to-day practice. The patient is usually symptomatic, complaining of itchy, scratchy or gritty eyes.

An interesting sidebar that's associated with DES is the fact that in some patients, the symptoms are paradoxical: teary or watery eyes. The watery eyes are from lacrimal gland stimulation from the discomfort of a deficiency of the moisture typically produced in the conjunctiva and eye lids. Typically, DES patients have mildly red eyes, which is probably one of the reasons why researchers now feel certain that DES is an inflammatory eye disease. LASIK surgery (especially within the first year) and contact lenses produce a lot of DES patients.

Divide to conquer

We break down the broad, generalized category of ocular surface disease (OSD) into primary and secondary OSD.

Primary OSD is rarer, but the patients are usually more miserably affected. The primary form is characterized by a loss of goblet cells and keratinization of the conjunctival epithelium. For the most part, it's associated with Sj�gren's syndrome.

Secondary OSD, however, is acquired because of environmental causes (pterygium, contact lenses, ultraviolet light) as well as diseases such as blepharitis and rosacea. Pregnancy and other hormonal imbalances, as well as LASIK refractive surgery (especially within the first year post-op), also cause secondary OSD.

Getting a bead on DES

The diagnosis of OSD and, by extension, DES -- whether primary or secondary -- is rather straightforward. Evaluate the patient's history and consider performing one or more of the following:

• tear break-up time (TBUT) with sodium fluorescein, which is best seen with a cobalt blue filter.
• Schirmer's test (or similar basal tear production test)
• Rose Bengal staining of the cornea and conjunctiva. Rose Bengal is invaluable in helping to differentiate between superficial punctate staining on a cornea or conjunctiva and actual devitalized tissue necrosis. This dye is best observed with the white light of the biomicroscope.
• lissamine green staining, which, according to J. James Rowsey, M.D., external disease specialist at St. Luke's Cataract and Laser Institute in Tarpon Springs, Fla., stains the areas on the eye surface where the patient feels pain. (This stain allows us to pick up problems with the biomicroscope that would normally be invisible).

Depending on the concentrations of the lissamine green and the Rose Bengal, authorities now favor more routine use of lissamine green over Rose Bengal.

Chronic blepharitis, as well as other lid pathologies such as chalazion and hordeola, can create corneal and conjunctival staining and a dry eye. Resolution of these disorders can usually reverse DES with no further treatment.

On the road to recovery

One of the earliest treatments for DES was punctal occlusion by electrocautery in 1935 by Beetham. In 1961, Foulds introduced the concept of temporary occlusion by inserting dissolvable gelatin implants into puncta to determine whether there would be merit in cauterizing these tissues.

It was in 1975 that Freeman described his design for reversible silicone punctal occlusion. Variations on Freeman's Eagle Vision theme are the FCI Umbrella plug and the Oasis Soft Plug, among others. Breakthrough ingenuity by Dr. Robert Herrick in the 1980s led to the development of the Herrick silicone intracannalicular plug (Lacrimedics Inc.) and in 2002 with the introduction of the soft gel SmartPlug (Medennium).

The doubting Thomases

The practice of occluding puncta has almost 75 years of history -- far longer than man-made artificial tears, ointments, steroids, neutraceuticals and cyclosporine. Over that time, experts have raised some legitimate concerns regarding punctal occlusion. For example:

► Consider occlusion via cautery or laser irreversible. This could become a problem if later on, for whatever reason, you feel the need to resume normal punctum-canalicular function.

► Intracannalicular occlusion, such as in the Herrick plug, have been implicated in cases of cannaliculitis and mucocele formation. Dacryocystorhin- ostomy surgery for repair has been reported.

► Occlusion with the Freeman-type silicone plugs can cause lid and corneo-conjunctival irritation to the point of requiring the plugs' removal.

► Herrick style and SmartPlugs aren't visible under biomicroscopy, so it's difficult to confirm in a practice setting that the plugs are in place. Silicone is radio-opaque, so you can identify it by X-ray. The new tinted opaque Herrick plugs are visible with transillumination.

► Occluding the punctum will increase the contact surface time of the eye's tears. Within the tear are pro-inflammatory cytokines (interleukin 1) and because there will be a delay in tear clearance, increasing the concentration of these cytokines might add greater irritation for the patient.

Those of us who've consistently used punctal occlusion as a viable method of dry eye treatment have found it an effective treatment. Sometimes, of course, problems occur. Probably the greatest problem with the Freeman/Oasis type plugs is spontaneous loss. For instance, we insert them properly and the patient notices relief; a month or so passes and the patient returns with dry eye symptoms. Upon examination, we find that the plug is missing.

The other scenario with this type of occlusion is that patients complain of irritation or instability with their toric soft contact lens. This occurs because of the plug's head rubbing tangentially against the lens edge.

More to come

In next month's column, I'll cover procedures for inserting punctum plugs and how to bill for punctal occlusion.

References available on request.

Dr. Christensen has a partnership practice in Midwest City, Okla. He's a diplomate in the Cornea and Contact Lens Section of the American Academy of Optometry. He's also a member of National Academies of Practice.