Patient education, proactive approach crucial when treating LASIK-induced dry eye

Issue: May 2000

Practitioners agree that dry eye syndrome may be one of the most commonly overlooked ocular conditions in patients who come in for an exam. Thorough testing using various disclosing dyes, determining tear break-up time and assessing tear volume with Schirmer’s strips can help highlight the problem, at which time the appropriate course of treatment may be determined.

However, a new group of dry eye patients is becoming more prevalent as the number of patients opting for refractive surgery increases. Doctors are estimating that more than 70% of patients who undergo laser in situ keratomileusis (LASIK) suffer from dry eye symptoms, ranging from several days to a few months following the procedure. Tests to determine a dry eye condition, prior to referring the patient for LASIK, have become more important than ever.

Why does LASIK cause dry eye?

The reasons behind this phenomenon are still being debated. Practitioners say that a certain amount of nerve damage likely occurs when the epithelial flap is being created. “There are several schools of thought on the actual etiology of the symptoms,” said David Eldridge, OD, executive vice president of clinical affairs for TLC Laser Eye Centers. “There is a theory that by cutting across the cornea, you cut the corneal nerves, and it decreases the stimulus of the eye, the feedback mechanism from the eye to the brain. Therefore, you have a reduction in the production of tears.”

Other theories involve goblet cell disruption caused by the suction ring that is placed at the limbus — a site that boasts a high concentration of goblet cells — as well as the idea that an alteration of the tear flow has been brought about by LASIK. “My hunch is that it’s probably a combination of those three as opposed to just one specifically,” said Paul M. Karpecki, OD, clinical director of cornea and refractive surgery for Hunkeler Eye Centers. “Not all patients are affected, but a very high percentage are.”

Previous sufferers more prone to dryness

Whether neurotrophic in nature or otherwise, patients who already suffer from dry eye going in are likely to experience the symptoms even more severely following the procedure, said Robert P. Wooldridge, OD, clinical director of the Eye Foundation of Utah. “LASIK can absolutely aggravate the condition and, in fact, virtually always does,” he told Primary Care Optometry News. “In an eye that’s already dry, after the procedure the dryness becomes more severe than it has been in the past.”

Conducting thorough preoperative testing is crucial, said Dr. Karpecki, as is educating patients about their condition and keeping them informed about what to expect afterward. “If patients understand that this is a normal, temporary side effect, they often do quite well,” he said. “But if they’ve got pretty dry eyes going in and you don’t tell them, it can start to cause problems, because they get these unexpected symptoms.”

Collagen plugs as a pre-emptive measure

Inserting collagen plugs immediately following surgery can help keep the patient from experiencing notable dry eye symptoms, said Dr. Wooldridge. “We routinely place collagen punctum plugs immediately following the surgery,” he said. “Dry eye after LASIK is so common in our practice that, as a matter of routine, we place collagen plugs in the patient at that time.”

If a patient has severe dry eye prior to surgery, the temporary plugs may even be inserted the day before surgery is scheduled, said Dr. Eldridge. “If you have a severe dry eye patient who was miserable with contact lenses and has an extremely low production volume of tears, then he or she probably needs plugs put in the inferior and superior puncta before surgery,” he said.

Often a short-term condition

While the time frame varies from patient to patient, doctors say that those with no history of dry eye are likely to suffer from a relatively short period of dryness. It could last from several days to just a few weeks, but the majority averages approximately 3 months, with some extending as long as 6 months, said Dr. Karpecki. “There is an average of 3 months in most patients,” he said. “Some theories suggest that it takes about 3 months to regenerate those nerves. If you have a dry eye patient going into it, this is going to exacerbate it for a short period of time. I often tell patients that it’s likely going to make their dry eyes worse for 3 to 6 months. After that, they will probably return to the same amount of dryness.”

Be straightforward about the condition and present dry eye patients with the various treatment options available, including punctal cautery, urged Dr. Wooldridge. “I emphasize to the patients with chronic dry eye problems that this is a chronic disease, for which we have no cure, but we have treatment options to lessen their symptoms and make them more comfortable,” he said. “None of the treatments are perfect; they all have potential risks and benefits.”

Artificial tears, silicone plugs

After the procedure, start the patient with a frequent dosage of unpreserved drops for maximum comfort and vision quality, advised Dr. Eldridge. “We try to use unpreserved drops initially when we know the patient will use them more than three times a day,” he said. “We tell patients to use lubricant drops — sometimes every 30 to 60 minutes a day when they’re awake — during their first few days of recovery following LASIK. This is for dry eye symptoms but also quality of vision — when the epithelium is kept moist, the quality of vision is better.”

Some experimentation may be required to determine the drop that is best suited for each particular patient. Dr. Karpecki said that he may use thicker suspension drops such as Celluvisc (carboxymethylcellulose, Allergan), a gel such as GenTeal (hydroxypropyl methylcellulose, CIBA Vision) or preservative-free tears for a minimum of 1 month postoperatively. These are often prescribed in conjunction with the dissolvable collagen plugs, which practitioners recommend to help get patients through the most difficult postop dry eye period. “A collagen plug, which may take 5 to 7 days to dissolve, can get patients over the hump to where they are fairly comfortable for a period of time. Then, they do well with tears,” Dr. Karpecki said.

Dr. Wooldridge advised monitoring the progress and changing the tear dosage based on the response. “Tears may be used as long as patients continue to show signs or symptoms of dryness,” he said. “It’s gauged by how the cornea looks and how the patient feels.”

Instilling drops before engaging in activities that may promote irritation, such as extended computer use or exposure to wind, can help stop the problem before it starts, said Dr. Karpecki. “If patients wait until their eyes get irritated and the inflammatory cascade has kicked in, it’s often too late to put the brakes on it,” he said. “There is a tendency for patients who get a fair amount of irritation to be more prone to regression of LASIK.”

If the patient still complains of dryness a few weeks following surgery, silicone plugs may be warranted, said Dr. Wooldridge. “I prefer to close all four puncta with the temporary plugs, and if the patient does not have excess tearing with both upper and lower puncta occluded, it would be highly unlikely for him or her to have excessive tearing with just the lower ones closed, which is what I do with the silicone plugs,” he said. “If the symptoms are abated with occlusion of the lower puncta, that’s fine. If the patient continues to have dry eye symptoms and the inferior plug is still in position, then we can talk about closing the upper puncta.”

While an infrequent occurrence, Dr. Eldridge said that silicone plugs have been removed on occasion. “You can put them in place, leave them in for an indefinite period of time and remove them if patients develop reverse symptomatology, or epiphora,” he said. “That can happen with some patients, so it’s nice to have a removable implant to reverse the process.”

Take a prophylactic approach

Practitioners should be proactive in their approach to treating dry eye in their patients, especially if they are considering refractive surgery, said Dr. Wooldridge, to achieve the most positive outcome. “Doctors need to ask very specific questions regarding drying, burning, sandy and gritty sensations and be on the lookout for this condition,” he said. “They’re doing a great service for their patients if they perform the simple diagnostic tasks, such as temporary collagen plugs, to ascertain whether patients do, in fact, have dry eye and whether punctal occlusion will make them more comfortable.

For Your Information:

David Eldridge, OD, is the executive vice president of clinical affairs at TLC Laser Eye Centers. He may be reached at 1323 East 71st St., Ste. 220, Tulsa, OK 74136; (918) 491-6162; fax: (918) 491-6168; e-mail: david.eldridge@tlcvision.com. Dr. Eldridge has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Paul M. Karpecki, OD, is clinical director of cornea and refractive surgery for Hunkeler Eye Centers. He may be reached at the Eye Center of Kansas City, 5520 College Blvd., Overland Park, KS 66211; (913) 491-3737; fax: (913) 469-6686. Dr. Karpecki has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Robert P. Wooldridge, OD, is the clinical director of the Eye Foundation of Utah. He may be reached at 5900 South, Ste. 201, Salt Lake City, UT 84107; (800) 756-6408; fax: (801) 262-9216. Dr. Wooldridge has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.