COMANAGEMENT Q&A

How to Manage a Patient with Intacs

Edited by Paul C. Ajamian, O.D.

Question: I have my first patient with intrastromal corneal ring implants. Are there any special considerations for comanaging this patient?

Answer:  Not necessarily. The post-op course of treatment for this patient is very similar to that for the garden-variety LASIK patient. Even the follow-up visits are the same: at one day, one week, one month, three months and one year, according to optometrist Paul Karpecki of the Hunkeler Eye Centers, Kansas City, Mo.

Dr. Karpecki adds that the therapeutic regimen for the intrastromal corneal ring segments (Intacs by KeraVision) is closer to that for cataract surgery than LASIK. This regimen consists of a steroid such as prednisolone acetate (Pred Forte) QID and an antibiotic such as ofloxacin (Ocuflox) QID. Discontinue the antibiotic at the end of the first week, and then taper the steroid over the next three weeks.

Question:  What types of complications should I look for?

Answer:  Complications are rare, but Dr. Karpecki suggests you do these three things as part of your exam:

• Inspect the location of the segments. The segments should not touch at the top, where the 12 o'clock incision is. Rather, they should be symmetrically spaced apart. If the PMMA segments migrate and meet at the top, they can block aqueous from entering the incision. This aqueous fluid brings nutrients to heal the wound.

A problematic wound could lead to inflammation, alter the refraction or even cause a corneal melt. Make sure to refer such a patient back to the surgeon.

Interestingly, if the segments migrate and touch at the bottom, it's usually not a problem and the refraction will not change. By the end of the first week, the segments should be stable.

• Look at the incision itself. A normal incision should be tight and closed. If the incision gapes open—where the segments have migrated upward for instance—the result may be an undercorrection of vision.

Of course, the incision might develop white fibrotic scarring and heal too tightly. This could induce astigmatism in some cases.

These instances are uncommon, and only require treatment if they cause patient symptoms related to the residual refractive error. Only about 2-3 percent of incisions do not heal as they should, Dr. Karpecki estimates.

• Be on the lookout for infiltrates or infection, as you would with any refractive surgery. These, too, are rare in this procedure; Dr. Karpecki recalls just one case among the entire clinical trial. If anything looks suspicious, however, send the patient back to the surgeon or carefully treat for infection.

One final note: Haze or deposits inside the channel are normal findings and very likely are not cause for alarm.

Question:  In what instances should the intrastromal implants be replaced or removed? 

Answer:  The decision to remove the implants depends on the corrective outcome, which takes several weeks to stabilize, or whether a complication occurs. Dr. Karpecki makes an analogy to contact lenses. "With Intacs, like RGPs, patients take a little bit longer to get to their endpoint," he says. "But when they do, they get high-quality vision, often better than 20/20." For that reason, do not consider replacing the implants until the three-month visit, unless a complication develops beforehand.

Patients often undergo enhancement when they are undercorrected by 0.75D or more in the dominant (distance) eye, or if they have 1.00D or more of cylinder, Dr. Karpecki says. Even so, the decision really depends on the patient's satisfaction.

There are two options for over- or undercorrection:

• Exchange for thinner or thicker implants, depending on the residual refractive error.

• Remove the implants, wait until the refractive error returns to preoperative levels (usually within three months, though some return to original refractive errors within two weeks), and then perform LASIK.

If the patient needs enhancement due to astigmatism, the second option is the only choice.

Send comanagement questions to Review of Optometry, 201 King of Prussia Road, Radnor, PA 19089, or e-mail them to reviewofoptometry@jobson.com.