Minimizing Dry Eye Post-Surgery
DRY EYE REPORT
Minimizing Dry Eye Post-Surgery
Clear up dry eye before surgery to limit problems postoperatively, achieve the desired visual outcome and ensure patients are satisfied.
By Douglas K. Devries, OD
Working in a surgical practice, we see patients who are undergoing various refractive procedures as well as cataract surgery with standard and premium IOLs. Patients often present with some degree of dry eye that should be managed before surgery. Addressing dry eye pre-operatively ensures the best outcomes in terms of vision and surgical recovery, plus it means that patients are far less likely to experience dry eye after surgery.
If you're in private practice, it benefits you and your patients to address dry eye in your office before referring patients. We see many patients who haven't been tested for ocular surface disease and if they need treatment, it delays their surgery. If you screen and treat for dry eye, not only can you collect the revenue from dry eye treatment, you can also ensure the continuity of your patients dry eye treatment long term.
Why Treat Before Refractive Surgery?
Dryness is refractive surgery's number one post-surgical complaint. In creating a flap, the surgeon cuts nerves that interfere with neural feedback necessary for the tear production cycle. Suction of the microkeratome will damage goblet cells that are responsible for the soluble mucins which can then lead to a decrease in tear break-up time. After surgery, patients don't have the same neural response telling the lacrimal glands to produce tears.
If we miss a patient's dry eye before surgery, that patient will require very aggressive treatment after surgery. He may not need eyeglasses or contact lenses, but he may be more uncomfortable and perhaps dissatisfied with his outcome.
Optimally, we want to address dry eye preoperatively to be sure the ocular surface is in the best possible shape. In addition to reducing post-op dry eye, treatment before surgery gives us an accurate refraction without the muddying effects of dryness or fluctuation. This is important because we need a specific, accurate target.
Key: Why Patients Want Refractive Surgery
It's imperative that we diagnose any dry eye problems before refractive surgery, and the first step is to find out why the patient wants surgery. He may have tried and failed with contact lenses or experienced a decrease in contact lens comfort or wear time. The underlying problem could be contact lens intolerance secondary to dry eye. We can correct his vision, but first we have to address the underlying ocular surface problem.
We perform a dry eye evaluation to establish a correlation between signs and symptoms. The symptoms can be determined through a questionnaire or a case history. A thorough case history tells us the medications the patient is taking, including birth control pills, hormone replacement therapy, or other medications that could exacerbate dryness. It also includes questions about occupational and vocational environments, as well as lifestyle and habits (for example, hours per day spent on the computer).
We must rule out nocturnal lagophthalmos as well. Contact lenses worn during the day will often mask the dryness that's created during sleep from the eyes being slightly open. Before surgery, we need to identify the problem and address it both before and after surgery with moisture chamber goggles.
When patients have significant post-operative dry eye, it usually means there were some undetected symptoms before surgery. A good questionnaire helps close the gap between signs and symptoms, enabling us to capture even those patients with no clinical signs of dry eye.
Why Treat Before Cataract Surgery?
Like refractive surgery patients, cataract patients will experience less dry eye and greater satisfaction after surgery if we treat dry eye in advance. In addition, because many cataract patients are candidates for premium IOLs that provide multifocal, accommodating, or astigmatism correction, it is critically important to treat dry eye and identify any other pathologies that could affect the outcome of surgery.
If patients have ocular surface disease, it can distort the image prior to passing through the new IOL. This will result in a less-than-ideal image focusing on the retina. In addition, the distortion of the cornea can impact pre-operative testing and IOL selection. When we measure the axial length, keratometry (K values) are key. If we're getting an inaccurate K reading, then the entire calculation can be off, and we won't have the proper IOL power if the K readings are not accurate. After surgery, the patient can have a fluctuating, poor quality image that isn't close to meeting the objective of reducing spectacle correction as much as possible.
Before cataract surgery, we identify all pathologies, with ocular surface disease being the most prevalent. While we treat all dry eye aggressively to get the best potential visual acuity, the increasing popularity of premium IOLs has pushed this concept, largely because ocular surface disease can be one of the more debilitating conditions to patient who has a multifocal IOL. When patients pay for a premium IOL based on the expectation of quality vision, we need to do everything possible to meet that expectation.
Before and After Cataract Surgery
Cataract patients are an older demographic than refractive patients, so dry eye may be even more common. It's good for referring optometrists to put nearly all cataract patients through a dry eye evaluation. This should be conducted at a separate visit and can include some or all of the following:
• measurement of the tear meniscus
• fluorescein staining
• checking the tear breakup time
• lissamine green staining
• expressing and evaluating the quality of meibomian gland secretions
• performing a Schirmer's or tear osmolarity test.
After surgery, the patient's vision is evaluated relative to the target. If the results are good, there is no fluctuation, and the patient feels comfortable, then we have a good result. If the patient feels he doesn't have the visual acuity that he was seeking, then we look back at the dry eye evaluation. Even if we addressed the problem before surgery, the patient may have some dry eye after surgery, so we treat it and re-test the patient's vision. Cataract patients are typically seen at 1 day, 1 week, 1 month, and 3 or 4 months after surgery, so if a problem is discovered post-surgically, patients are often back with their referring optometrist.
Treating ocular surface disease prior to surgery begins with asking the appropriate questions. The symptomatic patients with minor clinical signs could easily slip through without treatment if the right questions aren't asked. Once symptomatic patients are identified, treatment can be initiated, and patients will be on their way to greater comfort and improved surgical outcomes. This will please not only the patient, but also the surgeon to whom you refer.
Treatment for Dry Eye Pre- and Post-Surgery
Dry eye treatment is similar for all patients, regardless of the type of surgery a patient is having. An important aspect of the dry eye exam is to differentiate lid involvement. Does the patient have meibomian gland dysfunction (posterior blepharitis)?
If there is lid involvement, we treat the lids as well as the ocular surface. We treat with warm compresses, lid hygiene, omega-3 supplements and medications such as topical azythromycin (or a longer course of oral doxycycline in severe cases). Lid involvement should also be cleared up before surgery because lids can harbor bacteria.
In mild cases without lid involvement, we begin by seeing if patients consider their dry eye controllable with four applications per day of artificial tears. Most patients with very mild dry eye find that this works. If patients need more than four drops, we step up to cyclosporine emulsion (Restasis, Allergan) twice a day. Many doctors combine this with an ester steroid such as loteprednol (Lotemax/Alrex, Bausch + Lomb) to address inflammation during a run-in period for the cyclosporine.
Another option is to start omega-3 supplements, but the patient will require higher levels of omega-3 than a typical supplement dosage and it will take effect slowly. So if my primary concern is to get the dry eye under control before surgery, I tend to use supplements in conjunction with other therapies.
If a patient has been following treatment such that the inflammation has decreased and the lids are improved, we consider punctal occlusion. In a mild dry eye patient, temporary collagen plugs can be used before surgery, and permanent plugs can be inserted if the patient still requires them after surgery. In the moderate dry eye patient, I proceed with the permanent plugs initially to avoid a relapse when the collagen dissolves.
The goal is to get the ocular surface in the best shape possible prior to surgery. If a patient develops dry eye postoperatively, the treatments are similar to the preoperative treatment, but they are more aggressive.
Dr. Devries is co-founder and residency director of Eye Care Associates of Nevada, a statewide medical/surgical comanagement referral practice in Sparks, Nev.
Optometric Management, Issue: September 2011