Ophthalmology Management

LTK OVERVIEW
Insights and Applications For Your Refractive Practice
This LTK pioneer offers some strategies for adding this new technology to your practice.
By Roger Steinert, M.D., Boston, Mass.

Our practice received one of the first commercially released Sunrise Technologies HYPERION LTK Systems immediately after the FDA approval in June 2000. Since then, we've learned a lot about laser thermal keratoplasty (LTK) and the patients who are best suited to it.

Here, I'll provide some insights about this different type of refractive patient as well as some strategies for incorporating the procedure into your practice.

The hyperopic population is definitely underserved. Of the 150 million patients in the United States who are age 40 and older, about 35% are between +1.00D and +2.00D. That's more than 50 million potential LTK patients.

Be advised, though, that the hyperopic patient is very different from the myopic patient. Two distinctive traits of hyperopes are:

Bilateral or Unilateral?

Should you perform bilateral or unilateral LTK? After taking an informal poll of my colleagues, I've found it's running 50/50 between those who will treat both eyes at the same time and those who treat one eye and then wait a couple of weeks to treat the fellow eye. Either strategy requires managing the optics.

If you treat only one eye, then you have to do something for the second eye -- whether it's spectacles or contact lenses -- in the interim. Obviously, patients who were wearing contact lenses can continue to wear a lens on the untreated eye.

Even patients you've treated bilaterally may still need some correction. Let's say a patient is -1.00D, for example, and too blurry to feel comfortable driving. I'll take any frame he has and provide low-minus single-vision lenses at no charge. I have an optical shop, which helps control the cost. But even if you don't have an optical shop, you could make an arrangement with a local one. For about $30, the patient will feel you've given him full service and an acceptable solution to his problem.

They appreciate function. As you know, hyperopic patients usually start life not needing vision correction unless they're extremely farsighted. But by the time they reach college age, they start to need reading glasses, and by the time they hit 40, they're totally dependent on reading glasses and starting to struggle with distance vision.

These patients view spectacles as evidence of their overall bodily decline, and they hate it. They've gone from a clear world to a blurry world and have the mind-set that they're becoming increasingly handicapped.

They're easier to satisfy. It's easier to make a hyperopic patient happy than a myopic patient. If you correct a myope to 20/20, he wants 20/15. On the other hand, if you give hyperopic patients vision that's in focus and reasonably functional, they're happy. In their minds you're not just correcting their vision, you're giving them back their youth.

LTK candidates are 40 years old and older with a strong desire to maintain an active lifestyle. They're usually financially stable and able to pay for refractive surgery, which they view as an investment in themselves.

Just as cataract surgeons need more than one intraocular lens, full-service refractive surgeons need more than one approach to laser vision correction. LASIK is great for myopia, and implantable contact lenses are now available for low myopia. Phakic and accommodative implants are still investigational, and you're not likely to consider clear lensectomy for a +1.00D or +2.00D hyperope. I believe LTK fills this niche well. The 16-spot procedure basically corrects up to 2.50D, and 32-spot LTK for higher correction is currently under FDA investigation.

LTK is safe and effective, with a minimal learning curve and straightforward follow-up. Basically, these patients are on autopilot. Once they re-epithelialize, no intervention is needed. You don't use steroids, you just support the surface with artificial tears.

LTK start-up costs are relatively low, and staffing is uncomplicated. The machines are easy to place in your office, and they're ergonomically friendly. Both patients and surgeons appreciate the convenience.

LTK Pearls

In laser thermal keratoplasty (LTK), the noncontact holmium:YAG laser projects an eight-spot treatment beam -- a single beam split by a prism -- simultaneously on the cornea through a slit lamp delivery system. To correct hyperopia, you apply two rings of eight spots. The laser energy shrinks the tissue of the eye in each of the 16 spots and causes the cornea to steepen just enough to allow light to be focused better on the retina.

To conceptualize the effect of the treatment, imagine you'd placed a purse string suture 360 degrees and cinched it up causing the central cornea to bulge forward.
Often, the two sets of spots will just barely connect, so it looks like a figure 8 or a small peanut shape.
Initially, you'll see a little coagulum of epithelium, and the underlying stroma has a gray haze. On a blue or green eye, it's invisible; on a brown eye with the right light it can be seen but fades away fairly quickly.
During the 3-minute drying time, have the patient practice staying still and looking at the fixation light. When the drying is complete, tell the patient to take a deep breath and hold it. Then step on the pedal and go.

The two sets of spots may connect to resemble a figure 8.5

As for the efficacy of the procedure, you'll find that LTK patients are happy right away. You can give a patient whose goal was improved near vision a reading card immediately after the procedure. Even though the epithelium has been dry, he'll probably read down to J3 almost immediately. After a few blinks, he's already seeing well.

With distance vision, you need to be aware of an overcorrection at first. If plano is your goal, you will have to go into the minus area somewhat.

A nonsteroidal drop helps keep patients comfortable. And several surgeons also have started pinching off the small coagulated epithelial spots, which have to get sloughed and re-epithelialized anyway. By pinching these spots immediately after treatment, you'll encourage rapid re-epithelialization and may avoid the foreign body sensation of the coagulated spots.

Typically, patients can go to work and function quite well the day after the treatment.

You may have to make allowances for regression with LTK in some patients, but I think this issue has been overemphasized. Most patients will have a long-term effect. The people in the FDA studies who didn't have a long-term effect were younger patients. Patients older than 40, particularly those older than 45, may have a long-term effect.

I've found that most movement occurs during the first 2 weeks postop and is largely over in the first 4 weeks. From that point, you may see a slight change but generally not more than a half diopter for the average patient. From 6 months on, the debate is whether there's real regression or whether the patient is relaxing his residual accommodation.

Obviously, correcting hyperopia is the primary indication for LTK. However, Sunrise Technologies also has a clinical study in progress to evaluate the efficacy of the procedure for fine-tuning an overcorrected LASIK patient. In addition, Sunrise has another clinical study underway utilizing a monovision technique. This is a huge untapped market.

We now have procedures that meet most patients' refractive needs, and there's real value to giving them total vision correction. Patients respect and respond to that diversification.

When you offer LTK, you're telling patients that yours is a true refractive practice, not just a LASIK center. And because scheduling, preoperative care and the surgery itself are so straightforward, your office productivity will increase as well.

Dr. Steinert is in private practice at Ophthalmic Practice Consultants of Boston. He's an associate clinical professor at Harvard Medical School.

LTK Benefits Your Patients Will Like

Laser thermal keratoplasty (LTK) is safe and effective. Among its advantages are:

1 Minimally invasive. LTK doesn't cut or remove tissue and preserves the central cornea.

2 Comfortable. LTK is patient-friendly and office-based. Patients appreciate a procedure that can be performed while they're sitting upright at a non-threatening machine.

LTK Benefits You Will Like

1 Straightforward. There's a learning curve for everything, but this is one of the easier procedures you'll learn. Basically, you work your way through several screens where you input patient demographic information, refractive data, treatment planning and so on.

2 Titratable. You can adjust the exposure time and pattern of the laser pulses according to a patient's needs.

3 Excellent safety profile. Data from the study submitted to the FDA to obtain approval show no loss of best spectacle corrected visual acuity.