John A. Hovanesian, MD, FACS
WHAT IS PREMIUM OR REFRACTIVE CATARACT SURGERY?
First, let’s define premium or refractive cataract surgery as happening any time the surgeon takes extra steps in a cataract procedure beyond the covered services defined by Medicare, with the aim of achieving a specific refractive result, usually to achieve some degree of spectacle independence. Some of these extra steps are diagnostic, such as corneal topography to define corneal astigmatism beyond the more limited information given by keratometry alone. Some are therapeutic, such as performing limbal relaxing incisions (LRI) intraoperatively. Either way, these extra steps require more work (by the surgeon and his or her staff) than routine cataract surgery; and, more importantly, they require us to deliver to the patient on a promise of better vision.
HOW TO GET STARTED WITH PREMIUM CATARACT SURGERY
Walking the Walk
The first step in offering refractive cataract surgery is a consistent ability to perform uncomplicated surgery to achieve predictable results (ie, “walking the walk”). This means fairly atraumatic surgery through a small incision, a round capsulotomy of desired size (just under 6 mm for most lenses) and leaving behind a clean, intact capsule. For surgeons who are not completely comfortable delivering uncomplicated small-incision phacoemulsification, the prospect of offering refractive cataract surgery is likely to become an exercise in frustration for patient and physician alike.
Equipping the Office
Here, we will examine equipment that is commonly used in the preoperative assessment and postoperative treatment of patients and categorize these devices as essential, highly useful, and nice to have. Individual practice preferences apply, of course.
Preoperative biometry is, from a refractive standpoint, the most critical preoperative step toward premium cataract surgery. In recent years, contact ultrasound has given way to optical interferometry–based methods of keratometry, axial length, and anterior chamber depth measurements using the IOLMaster (Carl Zeiss Meditec) or Lenstar (Haag-Streit) instruments. Both instruments depend on patient fixation and are limited in their ability to perform biometry in highly opaque cataracts, but both instruments offer much greater resolution and accuracy in axial length measurements than ultrasound methods, assuming they can produce an adequate signal-to-noise ratio. In cases of dense cataract, immersion ultrasound biometry provides the most accurate axial length measurement. A number of ultrasound devices can provide consistent results using immersion ultrasound, though this technique is somewhat more demanding and operator-dependent.
Lens calculation software incorporating new-generation formulas like Holladay II, Haigis-L, and Barrett is usually a worthwhile investment, even if extra costs are involved in obtaining these modern formulas. Especially in long and short eyes and those with prior refractive surgery, these formulas allow much more accurate prediction of intraocular lens (IOL) power than their early generation counterparts. For eyes with prior refractive surgery, an especially useful, free web-based calculator is available at www.ascrs.org. This calculator allows input of pre-refractive surgery keratometry and refraction (when available) and uses all the modern formulas described previously.
Corneal topography or tomography provides critical information on the eye’s only remaining structure that meaningfully refracts light after the lens is removed. Beyond keratometry, which measures only 2 points on the cornea, topography and tomography give both qualitative and quantitative information on thousands of points on the ocular surface. This aids in identifying an unhealthy ocular surface with areas of lost data or irregularity. These instruments pick up keratoconus, can detect which patients have had prior refractive surgery, and generally give a more accurate representation of cylinder axis than other instruments.
Most commercially available topography or tomography units can fill the need to provide an image of corneal surface power, but an additional useful feature is an estimate of the effective central power. The following devices can report values that can be used with the online calculator from the American Society of Cataract and Refractive Surgery1 for calculating IOL powers in eyes that have had previous keratorefractive surgery:
▲ ATLAS (Carl Zeiss Meditec): Average powers in the central 0, 1, 2, and 3 mm of the cornea (numerical view)
▲ EyeSys Corneal Analysis System (EyeSys Vision): Effective refractive power
▲ Tomey Topographic Modeling System (Tomey Corporation): Average central corneal power
▲ Ziemer Galilei (Ziemer Ophthalmic Systems): Total corneal power
Additionally, measurement of posterior corneal astigmatism may increase the predictability of astigmatic correction. The Ziemer Galilei, Pentacam (Oculus), and Cassini (i-Optics) instruments all claim to measure and report posterior corneal astigmatism.
Diamond LRI blades and associated markers (essential) allow correction of astigmatism during surgery and are absolutely necessary, unless a surgeon plans on using only toric implants. In Chapter 14, Dr. R. Bruce Wallace describes in detail how to plan and perform these procedures. Diamond LRI knives come in a variety of designs and from many manufacturers, including those of fixed incision depth, usually 600 microns, and those with a micrometer, allowing customized incision depth. The choice between these depends on which type of nomogram the surgeon will use and whether the same blade may also be used for more central (mini-radial keratotomy) incisions. Another feature to consider is the design of the metal guards adjacent to the diamond blade tip; some designs allow easier visibility of the blade tip than others during cutting. Finally, handle length can be important, as shorter blade handles are less awkward to use when performing enhancements at the slit lamp. Longer blade handles can interfere with the slit lamp swinging light source.
Optical coherence tomography (essential) has become an extremely valuable tool for the premium refractive surgery patient. When the presence of cataract precludes a clear view of the fundus, subtle abnormalities like epiretinal membranes, diabetic macular edema, and macular traction can be impossible to detect through examination alone. Identifying these abnormalities before surgery is essential to setting proper expectations. In general, the presence of any macular pathology that affects contrast sensitivity would be a contraindication to a multifocal implant. We also generally avoid accommodating lenses when macular pathology reduces potential visual acuity before surgery (or is expected to do the same soon after surgery) to less than 20/25. Naturally, exceptions exist; occasionally, highly motivated patients with mild macular pathology will appreciate the benefits of an accommodating lens. However, it is incumbent upon the surgeon to convey an appropriate expectation, taking into account all the information available, which usually includes an optical coherence tomography scan.
Femtosecond laser cataract surgery automates those steps of cataract surgery—capsulotomy, lens fragmentation, and incision creation—during which the inherent variability of manual techniques can reduce refractive predictability. Multiple peer-reviewed studies have now shown that these devices do indeed lessen endothelial cell loss and reduce anterior chamber inflammation after surgery.2,3 Many surgeons believe more precise refractive outcomes are also achieved with these instruments because, in theory, a more precisely created, more stable incision will allow fewer wound leaks after surgery and a more predictable capsulotomy will allow better consistency of the effective lens position.
Intraoperative aberrometry allows a surgeon to measure refractive error during surgery in the aphakic or newly pseudophakic state. A measurement performed after the lens is removed and corneal incisions are created will theoretically offer greater accuracy than one performed before surgery. Indeed, the growing sentiment among users of these devices is that they reduce the incidence of postoperative refractive “surprises” and the frequency of enhancements, especially for challenging patients with previous refractive surgery.
Surgical alignment systems (highly useful) assist in ensuring that toric implants and astigmatic incisions are aligned with the patient’s preoperative astigmatism. When a patient moves from an upright to a supine position, the extraocular muscles may induce several degrees of cyclotorsion. Additionally, inaccuracy of head alignment relative to its normal, upright position can cause meaningful error in placing treatment on the intended axis. Alignment systems measure landmarks on the eye with the patient upright, then, using those landmarks as a reference point, register the proper axis of astigmatic correction while the patient is lying down.
Nice to Have
Specular microscopy can be very helpful in assessing endothelial cell count in patients with Fuchs endothelial corneal dystrophy and the less common non guttate corneal endothelial dystrophies. Some refractive cataract surgeons perform these tests routinely on all patients before surgery, though this is not considered the standard of care. Naturally, the corneal endothelium can and should be assessed clinically at the slit lamp with specular reflection, and visual inspection will generally identify the presence of central guttate that can reduce contrast sensitivity even when endothelial function is preserved. The added benefit of a specular microscope is the ability to calculate cell density. This calculation, when combined with corneal thickness measured by a pachymeter, can be useful.
Ultrasound pachymetry can provide predictive value, helping identify patients who are more likely to have corneal decompensation. Generally, patients with central endothelial cell density less than 1000 cells/mm2 with corneal thickness greater than 600 microns are in a high-risk group, especially if the lens nucleus is brunescent or other comorbidities (such as pseudoexfoliation) make surgery challenging or risky.
Dry eye diagnostics, such as tear film osmolarity and testing for matrix metalloproteinases, allow objective measurement of a patient’s dry eye. Many clinicians choose to perform these tests to identify patients at risk for postoperative dry eye, and some use the test outcomes to educate patients as to why strict adherence to dry eye treatment regimens is necessary for the desired outcome. In Chapter 4, Dr. Jodi Luchs will further explore this topic and a proven approach to managing dry eye in these special patients.
Excimer laser surgery is a simple and effective way to correct residual refractive error after cataract surgery. It allows precision that cannot be matched by other methods of enhancement like piggyback lens placement or incisional enhancements and permits correction of residual astigmatism. Naturally, investing in an excimer laser only makes sense for a practice that offers laser refractive surgery as a revenue stream to defray the cost of the instrument. Having access to a laser in some manner helps make enhancements easy to recommend and perform. This is highly important, because the most common cause of patient dissatisfaction with refractive cataract surgery is residual refractive error—a problem that is generally easily remedied.
Talking the Talk
The second prerequisite to succeeding with premium cataract surgery is mastering personal communication with patients about expected and delivered results. This task is far more challenging and uncomfortable than the first for most surgeons, who are already able to perform predictable procedures. Why is this? The traditional doctor-patient relationship is governed by what psychologists call a social norm, yet when a patient pays out-of-pocket for an outcome of reduced spectacle independence, we introduce into the relationship elements of a market norm.4
To better understand social norms and market norms, consider what happens when an ophthalmic technician—let’s call her Amy—overwhelmed with an overbooked clinic schedule, works extra hard to perform workups in a timely manner, turns on extra charm with patients so they will remain calm despite delays, and stays late to make sure everyone is taken care of. Exhausted, before going home, she asks the doctor if there is anything else he needs. The doctor says, “Amy, I know you were really a trooper today. Thank you so much for looking out for our patients and taking a personal interest in them.” No matter how well Amy is paid, she feels she worked above the call of duty. She genuinely appreciates the praise and will most certainly repeat the same good behavior the next time the schedule is so overbooked.
What if the doctor, instead of praising her at the end of the day, handed the technician a $20 bill and unappreciatively said, “This is for staying late.” Most of us know (hopefully not from making this mistake!) that Amy would not feel the least bit rewarded for her good behavior. Her attitude would more likely be, “Is that what he thinks my extra effort is worth? I saved his practice today, and all he gives me is $20?”
Why is the first response, verbal praise, which has no material value, much more desirable than a monetary reward? Because when a boss gives praise, the interchange is governed by a social norm, where the technician’s hard work is a “gift” to her boss—a courtesy. It is returned in kind with a courtesy—a gift of praise and thanks. When the boss gives $20, the interchange puts a numeric value on her “gift.” The boss expresses no appreciation. Their relationship is suddenly governed by market forces, or a market norm. Predictably, Amy has a feeling of underappreciation.
In the traditional doctor-patient relationship, a patient seeks a physician’s aid for relief from a medical problem, placing all his or her confidence in the doctor and trusting that he or she will choose the best medicines and materials for curing the ailment. To the best of his or her ability, the doctor renders treatment, and the patient understands that, whatever the result, it is the best that nature will allow. In traditional cataract surgery, even though the patient pays the doctor for the service, this payment is usually through a third-party payer, which isolates the patient from quantification of the payment. In fact, the financial aspect of the exchange is almost never discussed between doctor and patient. The physician performs his or her age-old duty, and the patient is grateful. This relationship is, therefore, governed by a social norm.
Enter refractive cataract surgery. No longer is the doctor merely curing an ailment. He or she is offering some degree of spectacle independence, a result that insurance carriers deem medically unnecessary. In doing so, he or she is seeking to profit from these added costs. There are counselors who function in a sales capacity and color brochures. This shifts the psychology of at least this part of the doctor-patient exchange to a market norm.
This shift in mental rules from those of social to those of market norms explains why refractive cataract patients are so much more demanding than those electing traditional results. Simply put, they expect to get what they’ve paid for.
This does not mean that offering refractive cataract surgery reduces the trust and admiration between doctor and patient. The most successful refractive cataract surgeons do not find their relationships with patients diminished by this dynamic but, rather, enhanced. Those surgeons who convey through words and body language a desire to deliver superior vision generally find that patients respond with appreciation and acceptance of this new concept despite the added costs.
Conveying genuine interest and confidence that the patient’s expectations will be exceeded is not a communication process that can be faked. Those surgeons who don’t completely believe their added services are worth the cost would do better not to offer them. A surgeon who will be annoyed by Mrs. Jones questioning the quality of her uncorrected vision after surgery of 20/25 and Jaeger 2 needs to rethink whether he or she is prepared for managing the psychology of refractive surgery patients. Mrs. Jones is most likely not an unreasonable person. She needs education in what to expect.
In Chapter 8, I will present 10 principles for communicating with patients before surgery. In Chapter 18, Drs. Eric Donnenfeld, Alanna Nattis, Eric Rosenberg, and Allon Barsam will give 7 Cs as reasons why postoperative patients can be unhappy and explore techniques for communicating that don’t erode the physician-patient relationship. Moreover, a growing number of courses and symposia at national and regional eye meetings are beginning to teach these principles using video and live role-playing, which demonstrate these concepts in a way that cannot be captured in this or any textbook. The successful refractive cataract surgeon seeks out these opportunities to learn better communication skills and continuously evaluates his or her own words from the perspective of the sometimes-unhappy patient. It’s not enough to just operate. We must also educate.
2. Conrad-Hengerer I, Al Juburi M, Schultz T, Hengerer FH, Dick HB. Corneal endothelial cell loss and corneal thickness in conventional compared with femtosecond laser-assisted cataract surgery: three-month follow-up. J Cataract Refract Surg. 2013;39(9):1307-1313.
3. Abell RG, Allen PL, Vote BJ. Anterior chamber flare after femtosecond laser-assisted cataract surgery. J Cataract Refract Surg. 2013;39(9):1321-1326.
4. Ariely D. Predictably Irrational: The Hidden Forces That Shape Our Decisions. New York, NY: HarperCollins; 2008.