May 2017

 

COVER FEATURE

 

Treating the cornea before cataract surgery
Primer for dry eye diagnosis and treatment before cataract surgery


by Vanessa Caceres EyeWorld Contributing Writer

   

Lissamine green staining of the conjunctiva and cornea
Source: Vincent P. de Luise, MD, FACS

For better surgical outcomes, don’t miss this all-too-common ocular surface problem

Dry eye before cataract surgery is more common than you might think. Although estimates vary, a PHACO study which focused on the prevalence of dry eye in cataract surgery found that almost two-thirds of patients had clinical signs of dry eye.
Even still, Edward Holland, MD, director of cornea, Cincinnati Eye Institute, Cincinnati, said he thinks dry eye is “one of the most underrecognized and neglected conditions.” “There are an estimated 55 million people with dry eye, but only 16 million receive a diagnosis,” he continued. “In cataract surgery, the busy comprehensive surgeon is not always looking out for dry eye.”
“With cataract surgery, it’s our obligation to consider every patient as possibly having dry eye,” said Vincent P. de Luise, MD, FACS, assistant clinical professor of ophthalmology, Yale University School of Medicine, New Haven, Connecticut, and adjunct clinical professor of ophthalmology, Weill Cornell Medical College, New York.
Dry eye left untreated before surgery can worsen postoperatively, potentially leading patients to think the surgery—and the surgeon—did something wrong. By evaluating and treating dry eye before a cataract procedure, you can stop patients from blaming you for less than stellar results.
Although the diagnosis of dry eye before cataract surgery is important in all patients, it’s especially crucial in premium IOL recipients. Patients expect excellent outcomes with premium IOLs, and a problematic ocular surface can affect results. “You want a wow factor for them,” Dr. de Luise said.
“We have to do extra due diligence from a chair time standpoint and with appropriate diagnostics so we can achieve our refractive target and outcomes,” said Elizabeth Yeu, MD, Virginia Eye Consultants, Norfolk, Virginia.
Here’s a primer on how to evaluate and treat dry eye in your cataract surgery population.

Evaluation, diagnosis

Before you even see patients, educate technicians and other staff members about the prevalence of dry eye, Dr. Holland recommended. This prompts them to keep dry eye forefront in their mind as they evaluate patients.
Many dry eye-focused ophthalmologists will use questionnaires such as the SPEED II questionnaire—available online—to assess patient perception of ocular surface problems.
However, because not all dry eye patients will have symptoms, your diagnostic testing needs to go beyond just the questionnaire, said John Hovanesian, MD, clinical instructor, Jules Stein Eye Institute, University of California, Los Angeles. Dr. Hovanesian, along with other dry eye experts, uses tests such as tear film osmolarity. “Tear film osmolarity is considered abnormal when it’s greater than about 308 in either eye or there’s a variability greater than 8 between eyes,” he said. “That would usually indicate there’s a component of aqueous deficiency.”
Another test commonly used is the matrix metalloproteinase-9, which can help indicate if inflammatory dry eye is present, Dr. Hovanesian said.
Tear film break-up (TBUT) time is another long-standing test used; in the PHACO study, TBUT was abnormal in about two-thirds of patients scheduled for cataract surgery, said William Trattler, MD, Center for Excellence in Eyecare, Miami. Dr. Trattler was a lead investigator in the PHACO study, which was presented at several meetings but not yet published.
Topography and keratometry are two revealing tests when evaluating the ocular surface. “You can see the quality of the topography is related to the quality of tear film and the ocular surface,” Dr. Trattler said.
Although corneal staining has an important role in dry eye assessment, Dr. Holland shared this pearl: “Many times, you see charts where it says that corneal staining is a sign of moderate dry eye. If they put in fluorescein as the only stain and don’t see staining, they think the patient doesn’t have dry eye. I argue that corneal staining is a sign of severe dry eye. By the time there are multiple epithelial erosions, that patient has long-standing dry eye, not moderate dry eye,” he said. Don’t use staining as your main defining test for dry eye, Dr. Holland cautioned. When staining, Dr. Holland uses lissamine green, which can stain abnormal conjunctiva, whereas fluorescein only stains absent epithelium.
A thorough slit lamp exam should be a regular part of the dry eye assessment as well. Dr. Holland checks the eyelids for lagophthalmos, examines the conjunctiva, and analyzes the lid margins. When pushing on the meibomian glands, what comes out should be free-flowing, not opaque, paste-like, or hard to express, he said. “All of these things are done with a quick slit lamp exam,” he said.
“Schirmer I testing can provide value, if performed correctly. A 1-minute Schirmer I measurement multiplied by three provides a reasonable estimate of the five-minute result, and is much less irritating to the patient,” said Dr. de Luise.
Another test he recommends is the Zone Quick Test, in which a thread impregnated with phenol red is placed in the outer lower conjunctival sac for 15 seconds, and the amount of tear wetting is measured.

Explaining to patients

If you find dry eye in patients, they may be surprised to hear that their cataract surgery can’t proceed right away.
“I wish all patients would have good keratometry and topography readings out of the gate, but it’s frustrating because they often have dry eye, making these tests inaccurate,” Dr. Trattler said.
The first thing Dr. Yeu does at this point is spend some time asking patients about symptoms such as intermittent blurred vision. She points out that intermittent blurred vision is a sign of dry eye, not their cataracts. Creating awareness of the problem helps to establish common ground, so patients recognize the importance of dry eye treatment, Dr. Yeu said.
Dr. Hovanesian emphasizes to patients that dry eye is a chronic issue that will require their help to manage. “I tell the patient, ‘You have two diseases. We can fix the cataract, but we can’t cure the other. Dry eye is a lifelong issue and it will affect your vision even after cataract surgery.’ I also tell patients, ‘I can’t treat your dry eye, you have to treat it.’ They understand that they bear responsibility for success,” he said. Explaining the role that patients have in dry eye treatment helps boost compliance.
Although every practice is a little different, the surgeons interviewed for this article generally still schedule surgery in patients with dry eye, but they may slightly alter the surgery schedule. This allows patients to use their treatments and then come in for a reevaluation.
“They’re coming in expecting to have cataract surgery scheduled, and it’s disappointing to leave without a date,” Dr. Yeu said. “I generally have a 2- to 4-week turnaround time for surgery. If it’s mild to moderate, I’ll push those dates out 6 to 8 weeks. If they’re really unstable, maybe with a history of Bell’s palsy, exposure keratopathy, or other extraneous issues, then I’ll give dates that are 2 or 3 months out but have them come back in at 2 to 3 weeks to repeat measurements.”
If a patient has only mild dry eye disease, without any corneal staining, and is receiving a monofocal IOL, Dr. Yeu may still go ahead and schedule surgery with a normal timeframe. Counseling the patient on their diagnosis, and the potential implications of worse dry eye in the post-operative period should be discussed with the patient. Such patients should be offered dry eye therapies pre-operatively, to be used indefinitely in some cases.

Treatment for preop OSD

Treatment for dry eye and OSD in patients scheduled for cataract surgery will vary depending on the type found.
Many dry eye patients will have a meibomian gland dysfunction (MGD) component, which is especially common in an aging population, Dr. Holland said. In these patients, he favors omega-3 therapy and is aggressive about recommending thermal pulsation therapy with LipiFlow (TearScience, Morrisville, North Carolina). “It heats the lids, pulsates the glands, and evacuates the old meibum. Lipiflow is the most effective therapy to relieve the MG obstruction and restore MG function. I don’t think anything else jumpstarts therapy as much,” Dr. Holland said.
Depending on the patient, Dr. Holland may add oral doxycycline or consider topical azithromycin as well as a lipid-based tear.
For MGD, Dr. Hovanesian recommends the use of warm compresses and Avenova (NovaBay Pharmaceuticals, Emeryville, California) or OcuSoft scrubs (OCuSOFT, Richmond, Texas).
Patients with inflammatory dry eye often will need a short course of ocular steroids. Generic steroids can contain preservatives that are harsh, so Dr. Hovanesian favors Lotemax gel (loteprednol etabonate ophthalmic gel 0.5%, Bausch + Lomb, Bridgewater, New Jersey). “It’s very gentle on the surface, and there’s a low risk of pressure spikes,” he said.
For aqueous-deficient dry eye, lifitegrast (Xiidra, Shire, Lexington, Massachusetts) or Restasis (cyclosporine ophthalmic emulsion 0.05%, Allergan, Dublin, Ireland) are often used. “In the context of cataract surgery, lifitegrast may be better because it has a faster onset of action,” Dr. Hovanesian said. Dr. de Luise has found that cyclosporine works best in his aqueous-deficient patients.
In addition to medications, Dr. de Luise will address environmental changes patients can make, such as using a humidifier.
The coupling of various therapies does a more effective job at improving the ocular surface, Dr. Yeu said. When she sees intense staining even after treatment, Dr. Yeu will use the PROKERA amniotic membrane (AM; Bio-Tissue, Doral, Florida) or amniotic membrane drops (Ocular Science, Manhattan Beach, California) used off-label. “AM therapy can provide a relatively rapid turnaround on their surface, enough to capture accurate diagnostic measurements for them [after that],” Dr. Yeu said.
Many patients with aqueous tear deficiency dry eye will require therapy with an agent like lifitegrast indefinitely because of the chronic progressive nature of dry eye disease, Dr. Holland said.
Prior to surgery, dry eye is usually treated for 2 to 4 weeks before patients are reevaluated. “If everything is good, we’re good to go. If not, we need to delay the surgery, which happens rarely,” Dr. Trattler said. Occasionally, a patient’s vision improves so much with the therapies for dry eye that cataract surgery is not necessary at that time, Dr. Trattler said.
Still, there are situations where the patient’s ocular surface is not yet ready for surgery upon reevaluation. These patients might have been incompliant with drops or could require punctal plugs or additional therapy, Dr. Trattler said.
There are also situations where a patient may want a premium IOL, but the reevaluation reveals they just aren’t a good candidate, Dr. Hovanesian said. “You have to judge if a patient can sustain a good ocular surface before you choose a multifocal IOL for them,” he said. When Dr. Hovanesian has any doubts, he will use a Crystalens (Bausch + Lomb) instead of a mutifocal IOL, as the former tends to be better tolerated.
“If dry eye is severe, I’ll consider a toric IOL if we have consistent preoperative measurements for the magnitude and axis of astigmatism. However, I am reluctant to recommend a multifocal IOL in dry eye patients especially if there is an unstable tear film and corneal staining. Dry eye is the most common cause of unhappy multifocal IOL patients,” Dr. Holland said.
Because dry eye is a chronic condition, Dr. Hovanesian encourages surgeons to partner with a clinician who has a clinical interest in dry eye management to meet with the patient over time and consistently reevaluate for problems.

Editors’ note: Dr. Holland has financial interests with Allergan, Shire, and TearScience. Dr. Hovanesian has financial interests with Allergan, Bausch + Lomb, Katena (Denville, New Jersey), and Shire. Dr. Trattler has financial interests with Allergan, Bausch + Lomb, Johnson & Johnson (Santa Ana, California), and Shire. Dr. Yeu has financial interests with Allergan, BioTissue, Ocular Science, Shire, and TearScience. Dr. de Luise has no financial interests related to this article.

Contact information

de Luise
: vdeluisemd@gmail.com
Holland: eholland@holprovision.com
Hovanesian: johnhova@gmail.com
Trattler: wtrattler@gmail.com
Yeu: eyeulin@gmail.com