Hyperopia is the most common refractive error among the American population; yet, compared with their myopic counterparts, farsighted patients have far fewer treatment options to choose from beyond glasses and contact lenses. And these are patients who are highly motivated to explore procedures to help them experience better vision.

Even mild hyperopes tend to be very dissatisfied with their vision. Near and distance vision is usually compromised, and with age, unhappiness can turn into misery as presbyopia further complicates their lives. To make matters worse, the manifestation of these conditions normally occurs after the age of 40, meaning hyperopes are newly "trapped" in glasses or contact lenses.

Read on to learn how you may soon be able to perform laser thermal keratoplasty (LTK) to help these patients -- and your practice.

In January, the FDA Ophthalmic Devices Panel unanimously recommended approval of Sunrise Technologies' Hyperion LTK System. As of this writing, the system is under final FDA consideration for the treatment of +0.75D to +2.50D of hyperopia with no more than 0.75D of astigmatism.

In this article, I'll share my experiences as a clinical investigator of LTK to give you a headstart on expanding your practice using this procedure.

An overview of LTK

First, I ask myself three questions about any new procedure:

�        is it safe?

�        is it efficacious?

�        are my patients happy?

Clinical trials have shown LTK to be extremely safe; both eyes can be treated during the same visit. Adding to the safety profile is the fact that no corneal tissue is cut or removed. Instead, two concentric rings of eight simultaneous spots (16 total spots) of laser energy are applied with a pulsed holmium:YAG laser to the mid-periphery of the cornea at the 6-mm and 7-mm zones, gently heating the collagen. This shrinks the collagen, causing the cornea to steepen.

Preservation of best spectacle corrected visual acuity (BSCVA) and incidence of induced cylinder are well below FDA targets. The risk of ocular complications is negligible, and the rate of patient subjective symptoms is low. During U.S. clinical trials, there have been no reported laser-related adverse events or sight-threatening complications. Results show a significant reduction of farsightedness and a significant improvement in distance vision without glasses.

I've found LTK to be a simple and fast surgical procedure, which is good news for me and my patients. Operative time is approximately 1.4 seconds per ring of treatment. I've performed 80 LTK procedures, and my patients' reactions have been telling.

As soon as the procedure is over, I commonly hear "That's it? That's all there is to it?" And then something along the lines of "Wow! I can see the hands on my watch!" Now let's move on to a more detailed description of the procedure, beginning with proper patient selection.

Patient selection

Candidates for LTK must:

�        be at least 40 years old

�        have stable vision for at least 6 months

�        have healthy eyes

�        fall in the low-to- moderate range of hyperopia (+0.75D to +2.50D)

�        have no more than 0.75D of astigmatism.

Contraindications include visually significant cataracts, severe dry eye, autoimmune diseases and pregnancy.

System attributes

The Hyperion LTK System is built for the ophthalmologist's office. It's easy to install and to incorporate into the office routine because it requires no special wiring, cooling, gases, expensive disposables or a special room. The solid-state laser requires only minimal maintenance costs. The system stands 41 in. by 23 in. by 49 in. It weighs 400 lbs., and is on rollers so that it can be stored easily. Power requirements are 120 VAC, 15 amp maximum, 50/60 Hz or 230 VAC, 8 amp maximum, 50/60 Hz.

The system resembles a slit lamp, so it's non-threatening to the patient. Touch screen computer control of spot energy and orientation angles make the physician's experience simple, fast and elegant. The computer monitor displays all relevant information. The laser has multiple test points regularly monitored by an on-board computer to ensure safe, reliable operation.

The procedure's learning curve isn't steep because the system is user-friendly and doesn't involve any of the surgical equipment associated with other refractive procedures.

How to perform the procedure

The procedure is so easily integrated into the ophthalmic practice, you don't need to schedule a special day for LTK. It can be done between other procedures.

The patient sits upright as if undergoing an eye examination. Average chair time per procedure is designed to be about 5 minutes. Prior to the procedure:

�        A technician administers three sets of topical anesthetic eye drops, with 3 minutes between sets to allow the eye to dry. This can be done while the patient is in the waiting room or in the room where the system is housed.

�        A retainer is used to keep the eyelids open, and the other eye is covered with a patch. There is a 3-minute waiting period after retainer insertion to evaluate the tear film for any irregularities or uneven dry spots on the cornea.
If the eye isn't uniformly dry after application of the topical anesthetic, I remove the retainer, ask the patient to blink a couple of times, replace the retainer, and begin the 3-minute waiting period again.
If the eye isn't uniformly dry prior to treatment, it's theorized that there is a greater chance for induced astigmatism, although this hasn't been proven conclusively.
During the procedure:

�        I ask the patient to focus on the fixating light. Total time of the procedure is about 3 seconds, so the patient doesn't need to focus on the light for long. When the patient remains focused on the light, the chances of inducing astigmatism are further reduced.
The Hyperion system that will be launched following FDA approval will incorporate a passive eye-tracking mechanism to further minimize the effects of gross eye movement during the procedure.

�        Next, the 16-spot nomogram for the particular degree of correction is programmed into the unit's computer, and the laser is applied with the touch of the pedal for approximately 3 seconds. I have strictly followed the study protocol for the nomogram.

After the procedure:

�        The patient is given topical antibiotic drops. Non-steroidal drops are also an option. No postoperative patching is involved.

Managing patient expectations

When counseling potential LTK patients, I emphasize the excellent safety profile of the procedure, which has met or exceeded all safety requirements for laser refractive surgery set by the FDA in clinical trials. I carefully explain the procedure because I believe it's important to make patients aware that they will be overcorrected for 1 to 3 months, so their near vision improvement will initially be dramatic. The effect of improved near vision may diminish over time as distance vision improves.

In many cases, patients are free of their bifocals, and if a patient is still dependent on glasses after the procedure, it will probably be for reading glasses for fine print instead of needing multiple glasses for multiple focal points.

I don't perform LTK on the same day as the initial consultation because patients must undergo cycloplegia prior to treatment. Before patients undergo LTK, either before the day of surgery or on the same day, they must sign an informed consent document. After FDA approval of the Hyperion LTK System, physicians can use the consent form of their choosing.

Post-op issues

Post-op healing time is fast for LTK patients. Some may experience a foreign body sensation for a few hours. Antiobiotic drops and an over-the-counter pain reliever are usually all patients require. In terms of visual improvement, it can take a couple of weeks for the eye to stabilize.

During the LTK clinical trials, patients returned for post-op visits at 1 day, 1 week, 1 month, 3 months, 6 months, 12 months, 18 months and 24 months after the procedure. Following FDA approval, the timing of post-op visits will be at the discretion of the physician.

As is the case with all refractive procedures performed with lasers, LTK has regression associated with it. According to 10 peer-reviewed, published articles on hyperopic PRK or LASIK (see "Information for Comparison" on page 32) the regression curves from LTK were either equivalent to or less than those following excimer hyperopia treatment.

The LTK mean rate of change decreases progressively, reaching only 0.02 diopters per month between 18 and 24 months. Evaluation of the best fit regression curves following the procedure for low to moderate hyperopia indicates that if the curves continue at the expected rate, the corrective effect would be expected to dissipate no sooner than 11 years after the procedure.

It's also important to keep in mind that hyperopia progresses as patients age even if no procedure is done; all hyperopic laser procedures will result in a change in effect post-treatment, and none have been shown to stop the aging process. Following FDA approval, physicians will be allowed to re-treat at their discretion; however, long-term effects of re-treatment are unknown at this time.

LTK complements the excimer laser

I've been using the excimer laser for 10 years to treat myopia. As is the case with most doctors, I understand that no single technology will treat all conditions. The Hyperion System was designed specifically to reduce hyperopia, but excimer procedures and LTK aren't mutually exclusive. Rather, they can be complementary for surgeons who want to be able to treat both myopia and hyperopia.

And I firmly believe that surgeons will find that they can increase their refractive procedure volume dramatically because of the speed of the LTK procedure.

Will the patients come?

The simplicity of LTK should attract surgeons who have not yet entered the refractive surgery arena, but a question I hear often is whether the patients will come. I remember when we were first starting to treat myopic patients. We found them, and then word of mouth helped practices literally explode with patients in the late 1990s.

The demonstrated marketing ability of many ophthalmic surgeons, a bit of help from the medical device companies and the flood of information available to patients sent myopes streaming into practices. I believe we'll see the same dynamic with our hyperopic patients.

To help you as you generate the anticpated word-of-mouth referrals, Sunrise has prepared a marketing program for ophthalmic practices. Details will be released following FDA approval, but the program is designed to help individual physicians create market demand.

One thing we know for sure is that approximately 37 million Americans age 40 and older have hyperopia up to +2.50D. And baby boomers will continue to drive an increase in that number. A surgical alternative designed for hyperopia could ignite the hyperopic market the way that LASIK ignited the market for myopic treatment.

How much will it cost?

To help you incorporate LTK into your practice, Sunrise is preparing a lease program that will involve a volume-driven, per-procedure fee that will include all costs, including capital costs. The company believes physicians' per-patient cost to operate the Hyperion LTK System will be less than to operate an excimer laser.

Specifics will be unveiled after FDA approval, but the company's goal is to make LTK a profitable part of your refractive surgery practice. Now's the time to decide whether that's your goal as well.

For More Information

HYPEROPIC PRK

R. Brancato, F. Carones, A. Morico, E. Venturi, L. Vigo, A. Spinelli, G. Gobbi. Hyperopia Correction Using an Erodible Mask Excimer Laser Delivery System Coupled to an Axicon: Preliminary Results. European Journal of Ophthalmology. Vol. 7, no. 3, 1997; pp 203-210.

D. Dausch, Z. Smecka, R. Kleinm, E. Schroder, S. Kirchner. Excimer Laser Photorefractive Keratectomy for Hyperopia. Journal of Cataract & Refractive Surgery. Vol. 23, March 1997; pp 169-176.

S. Daya, F. Tappouni, N. Habib. Photorefractive Keratectomy for Hyperopia; Six Months Results in 45 eyes. Ophthalmology. Vol. 104, no. 11, November 1997; pp 1952-1958.

W. B. Jackson, G. Mintsioulis, P. Agapitos, E. Casson. Excimer Laser Photorefractive Keratectomy for Low Hyperopia: Safety and Efficacy. Journal of Cataract & Refractive Surgery. Vol. 23, May 1997; pp 480-487.

D. O'Brart, C. Stephenson, K. Oliver, J. Marshall. Excimer Laser Photorefractive Keractectomy for the Correction of Hyperopia Using an Erodible Mask and Axicon system. Ophthalmology. Vol 104, no. 11, November 1997; pp 1959-1970.

J. Pietila, P. Makinen, S. Pajari, H. Uusitalo. Excimer Laser Photorefractive Keratectomy for Hyperopia. Journal of Refractive Surgery. Vol. 13, Sept/Oct 1997; pp 504-150.

Vincigueerra P, Epstein D, Racie P, Azzolini, M. Long-term Results of Photorefractive Keratectomy for Hyperopia and Hyperopic Astigmatism. Journal of Refractive Surgery. 1998; 14 (suppl); S183-S185.

B. Sener, A. Ozdamar, C. Aras, A. Yanyali. Photorefractive Keratectomy for Hyperopia and Aphakia with a Scanning Spot Excimer Laser. Journal of Refractive Surgery. Vol. 13, Nov/Dec 1997; pp 620-623.

HYPEROPIC LASIK

K. Ditzen, H. Huschka, S. Pieger. Laser In Situ Keratomileusis for Hyperopia. Journal of Cataract & Refractive Surgery. Vol. 24, January 1998; pp 42-47.

Ibrahim, O. Laser In Situ Keratomileusis for Hyperopia and Hyperopic Astigmatism. Journal of Refractive Surgery. 1998; 14 (suppl); S179-S182.

Sandra C. Belmont, M.D., F.A.C.S., is a clinical investigator for the Sunrise Technologies U.S. LTK clinical trials for hyperopia. She's the director of the Laser Vision Correction Center and Corneal Service at New York Weill Cornell Medical Center, where she also directs the Corneal Fellowship Program. Dr. Belmont is also an associate professor of Clinical Ophthalmology at New York Weill Cornell Medical Center