Case in point

So, just what would go into the refractive decision making equation in a case with no clear-cut answers? The practitioners here weighed in on how they would handle a case involving a 45-year-old peri-menopausal woman with uncorrected acuity of –7 D refractive error and 20/20 corrected vision. The patient is a long-time contact lens wearer who has become uncomfortable in these of late. She also has a pair of cheaters for menu reading in dim light and would like to be free of these as well. Her ophthalmologist also determined that she had a thin cornea. Here’s what our experts thought. What would you do? Roger F. Steinert, M.D., would first determine if the patient was a monovision candidate and would do a comprehensive examination of her ocular surface looking for keratitis sicca. He sees the options here as primarily between PRK and LASIK. “PRK has the advantage that you’re going to have less difficulty with dry eye,” he said. “LASIK has the advantage that it’s not going to have the slower recover and the potential for haze and regression issues that PRK is going to have with that size correction.” For him a lot of the final decision would come down to the analysis of the tear production and the quality of the ocular surface, with a greater degree of dry eye tipping him towards PRK.
The other issue in the decision making paradigm here would be the concern about ectasia. “I personally would want a residual stromal bed of at least 300 microns before I would feel comfortable doing LASIK,” he said. “If I did LASIK I would definitely want to use the femtosecond laser and aim for a thin flap.”
If Dr. Steinert opted for PRK here he would consider using mitomycin C. “I’m a little conservative about using that in a large number of people because you don’t know the real, long-term issues with regard to keratocyte damage,” he said. As far as lens-based solutions, Dr. Steinert would be reluctant due to concerns about retinal detachment in a myope and also due to dissatisfaction with the current presbyopic lens solutions. “I don’t think that we really have the kind of high-performing presbyopic lens solution that would allow you to have a high-degree of capability and think that you’re going to have a happy outcome here.”
Likewise, Daniel S. Durrie, M.D., would present the patient with the option of doing thin-flap SPK or PRK. In the decision making process he would point to a study that he did involving thin flap LASIK in one eye and advanced PRK in the other in which the visual results were identical. The only difference was that the vision returned a little faster in the LASIK eye. “When I present it that way and say the vision isn’t going to be any different, you’re cornea is a little thin, why don’t we just do surface ablation,” he said. He would consider providing the patient with mini-monovision, with this approach, with Plano refraction in one eye and –1.25 D in the other—he finds that 98% of his patients tolerate this well.
As far as potentially using a phakic IOL, this is around the range when Dr. Durrie starts to consider the idea. “I would be looking at the depth of the anterior chamber, I’d be looking at the endothelial cell count, and I’d really be looking at why I can’t do laser on this patient,” he said. “If the cornea was really flat already in a 40 D cornea I might think about using a phakic IOL.” Usually, however he reserves these for 9 D of correction and above.
Douglas D. Koch, M.D., would assess the patient as a potential candidate for a phakic IOL by determining if her pupil status and endothelial cell count were adequate and the anterior chamber was normal. “Then the options I would present for her assuming that there is enough cornea, would be, a PRK with mitomycin for monovision, Visian ICL for monovision, or potentially refractive lens exchange,” he said. “I would talk mostly about the first two options for her.” Dr. Koch believes that he would be comfortable with either of these two options.
He is, however, less interested in doing a refractive lens exchange on a 45-year-old. “If her lens is completely clear I think that she’s much better served by having a Visian ICL,” he said. “She would get wonderful vision and it would tide her over for several years until she develops either a cataract or until an even better quality accommodating IOL is available.”