dry eye

Managing Surgical Patients

Minimize the risk of complications in the patients whom you co-manage.

KELLY K. NICHOLS, O.D., M.P.H., Ph.D.

How should you approach the risk of infection and ocular surface disease (OSD) in the surgical patients whom you co-manage? To answer this question, let's first look at the latest findings on the incidence rates of infection and OSD in ocular surgery patients, and then discuss a patient management plan that includes both pre- and postoperative care.

Infection: what is the risk?

Even with millions of ocular surgeries and intraocular injections performed each year, the risk of major complications, such as endophthalmitis, remains extremely low. The rates of endophthalmitis in cataract surgery have remained steady through the last several years, with one to two incidences reported per 1,000 cases each year, say recent estimates.

However, the low rate of occurrence doesn't matter to the few patients who experience this unfortunate event. Therefore, every effort should be made to optimize the surgical environment, including preoperative conditions, surgical techniques and postoperative care.

Preventing intra-operative ocular infection is not the only consideration in managing surgical patients. With surgical technology advancing at a rapid pace, we must ask: How does managing ocular surface disease fit into this arena? The following numbers provide an indication.

Dry eye and surgery numbers

It should come as no surprise that the patient demographic most likely to have dry eye and the demographic most likely to undergo ocular procedures are one in the same. Consider these statistics:

► Recent estimates indicate that approximately 15% of the population older than age 65 has dry eye.

► Cataract surgery is performed between one million and three million times annually in the United States, making it the most common outpatient surgery in this country. (If you assume that two million cataract patients are older than age 65, and 15% have dry eye, then approximately 300,000 of the patients who undergo cataract surgery each year will suffer from dry eye.)

► As a result of the aging "baby boomer" population, both glaucoma and age-related macular degeneration (AMD) surgical procedures are on the rise.

► With increasing research and popularity, ranibizumab and bevacizumab injections for AMD are becoming common co-managed procedures requiring ocular manipulation.

Looking beyond age-related issues to OSD, more than one million patients have undergone LASIK surgery annually in the United States through the past several years. Research has shown more than half the patients who undergo LASIK surgery experience symptoms of dry eye.

As we co-manage many cataract, AMD, glaucoma and LASIK patients, we play a key role in their pre-surgical ocular surface status and post-surgical management — two factors that in many cases determine the long-term success of these surgeries.

Does it really matter? Everyone has it …

Two presentations at the 2010 American Society of Cataract and Refractive Surgery (ASCRS) meeting highlight the prevalence of blepharitis in two specialty clinic settings: a high-volume cataract surgical center and a specialty retinal clinic for AMD. A high percentage of patients who participated in these studies had some form of blepharitis — anterior or posterior — which was characterized by decreased tear film break-up time (TFBUT), lid findings, blocked meibomian glands and/or abnormal meibomian secretions.

The prevalence of blepharitis (anterior and posterior) in 100 patients preparing to undergo routine cataract surgery was 59%, according to the first presentation ("Incidence of Blepharitis in Patients Undergoing Phacoemulsification" by Jodi Luchs, M.D., Carlos Buznego, M.D., and William Trattler, M.D.). The most significant clinical sign was plugging of the meibomian glands, with a mean score of 1.5, indicating mild to moderate gland blockage of the central 10 glands. Mean tear break-up time in the pre-surgical group was approximately 6.5 seconds in both eyes, which is considered abnormal.

The prevalence of blepharitis in patients with AMD (n = 50) was even higher — 86% of patients reported experiencing symptoms, such as burning/stinging/dryness, and 93% had at least one clinical sign of blepharitis, according to the second presentation ("Prevalence of Blepharitis Signs and Symptoms Amongst Patients With Age Related Macular Degeneration" by Rishi P. Singh, M.D.). The author reported 58% of patients had moderate to severe disease, and the most severe signs were lid margin redness and altered meibomian gland secretions.

While aqueous production (Schirmer test) was not reported in either study, one can speculate that these patients had evaporative dry eye or mixed evaporative/aqueous deficient dry eye. The Luchs precataract surgery study concluded:

"There is a real disturbance of the ocular surface as evidenced by the more rapid TFBUT in these patients. This can have potentially important implications for pre-operative measurements and post-operative outcomes of cataract and refractive surgery."

All of the patients in these studies could be considered good candidates for surgery. Yet both studies indicate that a high percentage of surgical candidates had ocular surface disease. Such findings suggest that the maintenance of ocular surface health and a stable tear film is a critical issue for optometrists to address in the care of the surgical patients whom they comanage.

Three steps to successful refractive correction

A patient's ultimate success with any modality for refractive correction depends on three things:

1. Appropriate patient expectations
2. Correct measurements, and
3. Minimal to no complications. If you consider fitting multifocal glasses, for example, setting an expectation of slight peripheral blur/distortion is as important as a correct distance and near refraction, accurate pupillary distance measurement, and within frame marking of the optical axis. You would not expect any complications.

The scenario is less straightforward when a patient with ocular surface disease is seeking a premium IOL with cataract surgery. Each of the aforementioned three conditions takes on additional importance in the management process. Communicating appropriate expectations are critical and require additional chair time, but pale in comparison to achieving optimal measurements. Arguably, the measurement of corneal curvature is one of the most important measurements in the pre-operative cataract surgery assessment — one which can be influenced by irregularities in tear film stability.

While no studies have been performed to my knowledge assessing dioptric change in keratometry (or similar) measurement in dry eye patients undergoing cataract surgery, studies have demonstrated topographic measurement changes due to tear instability in dry eye. It can be hypothesized that up to a ±0.50D measurement error could occur due to errors related to a non-stable tear film in ocular surface disease. Therefore, careful assessment of the lids and the ocular surface for significant disease is warranted to reduce risk for intraoperative infection as well as to provide the best tear film for preoperative measurements.

It starts with you

Your office is the portal to ocular surgery, and often a lag time exists between referral and the scheduled surgery. Use this time to optimize the ocular surface — initiate a management plan. For all presurgical patients, consider an aggressive approach in managing what some would consider "asymptomatic" lid disease and dry eye.

In addition to traditional lubrication, hygiene and warm compress therapy, prescribe topical azithromycin for apparent lid disease and/or cyclosporine 0.05% for aqueous deficient dry eye. The ASCRS presentations regarding the prevalence of blepharitis in cataract surgery centers or retina clinics may surprise you, but they underscore the importance of detecting and managing lid disease in patients before you refer them for surgery.

In many refractive surgery centers, pre-operative topical cyclosporine and collagen punctal occlusion are standard for patients presenting with any dry eye symptoms, and the use of autologous serum has even been recommended for moderate-to-severe dry eye preoperatively, says the study "LASIK and Dry Eye," from the March-April issue of Comprehensive Ophthalmology Update by Ikuko Toda, M.D. Your medical management of these conditions prior to referral may improve patient outcomes, as well as help grow your medical practice through patient satisfaction.

Post-operative care

Your job isn't over once the surgery is complete — some would argue it's just beginning. Following surgery, patients are using a number of topical drops, often including a steroid and antibiotic. Limited data exists on the benefit of additional therapies following ocular surgery, especially in patients who had ocular surface disease prior to surgery. However, a 2007 study published in Oftalmologia by Cornel Stefan, M.D., and Diana Melinte Dumitrica, M.D., showed that the addition of an artificial tear, q.i.d., for one week following surgery, significantly improved symptoms of dryness in patients post-cataract surgery.

The simple addition of a lubricant could improve the "final refraction" by stabilizing the tear film, preventing costly re-dos and improve patient's perception of the entire surgical process.

As O.D.s, we pride ourselves on our ability to decide with a patient when the "time is right" for ocular surgery, especially cataract surgery. A discussion about "improved surgical outcomes" may be the encouragement needed to convince a patient to initiate and maintain blepharitis and dry eye management — long after surgery. OM