EyeWorld Asia-Pacific June 2020 Issue

38 EWAP JUNE 2020 CORNEA P TK can be used for various types of corneal pathologies. Depending on the type of opacity and depth in the cornea, other treatments may also be needed. Experts discussed how they use PTK and the conditions for which they employ it. Perspectives of Christopher Rapuano, MD According to Dr. Rapuano, PTK was FDA approved in 1995 for treating corneal pathology. It’s good for treating several types of pathology, he said. One type is elevated opacities, like Salzmann’s nodules, keratoconus nodules, and elevated scars. “Some of those diagnoses don’t need PTK, but some of these opacities don’t come off well ܈̅ÃÕ«iÀwVˆ> ŽiÀ>ÌiV̜“Þ] >˜` you have PTK as backup,” Dr. Rapuano said. For those, Dr. Rapuano will bring the patient to the laser >˜` `œ ÃÕ«iÀwVˆ> ŽiÀ>ÌiV̜“Þ with a blade under the laser microscope. He said he usually gets a pretty smooth surface and will do a little PTK smoothing after that. “But sometimes it’s not very smooth after I’ve done a mechanical lamellar keratectomy, then I have the laser.” PTK offers a real advantage, he said, when you’re handling anterior stromal opacities or those in the front 15–20% of the cornea. Patients with ÃÕ«iÀwVˆ> ÃV>Àà >˜` “>˜Þ ÌÞ«ià of anterior and stromal corneal dystrophies can be treated. Most patients with granular corneal dystrophy, some patients with lattice corneal dystrophy, and occasional patients with macular VœÀ˜i> `ÞÃÌÀœ«…Þ V>˜ Li˜iwÌ from PTK. One of the pearls Dr. Rapuano gives when teaching about PTK is if it’s an anterior opacity and if most of the opacity is in the top 15–20% of the cornea, this could be a good candidate. But if it’s much deeper than that, the patient is probably not a good candidate. A lot of dystrophy patients have 80% of the opacity in the top 10% of the cornea and the other 20% is deep in the cornea, Dr. Rapuano said. When some physicians do PTK they think they have to get all the opacity out, and they take off a lot of the cornea. “That does a good job of getting rid of the opacity, but when you go that deep, you V>ÕÃi È}˜ˆwV>˜Ì ÃV>ÀÀˆ˜} >˜` y>ÌÌi˜ˆ˜} œv ̅i VœÀ˜i>] >˜` the results are bad,” he said. Even if you get only 80% of the opacity, the patient’s vision will improve dramatically without V>ÕȘ} È}˜ˆwV>˜Ì ÃV>ÀÀˆ˜} œÀ y>ÌÌi˜ˆ˜}° v ÞœÕ }œ ̜œ `ii« and there is scarring, the patient PTK for corneal pathology by Ellen Stodola Editorial Co-Director AT A GLANCE • PTK may work best if most of the opacity is in the anterior of the cornea. Even getting most œv ̅i œ«>VˆÌÞ V>˜ Li˜iwÌ Ì…i patient’s vision. • */ V>˜ Li `ˆvwVÕÌ Ü…i˜ ̅i pathology is very deep. If there is pathology more than 75–100 ï“ `ii« `i«i˜`ˆ˜} œ˜ ̅i corneal thickness, especially where it is most thinned), it can be challenging. • Haze could be a possible concern following ablation procedures. Mitomycin-C may help, along with other considerations. Contact information Hardten: drhardten@mneye.com Rapuano: cjrapuano@willseye.org Schoenberg: evan.schoenberg@gaeyepartners.com This article originally appeared in the April 2020 issue of EyeWorld . It has been UNKIJVN[ OQFKƂGF CPF CRRGCTU JGTG YKVJ permission from the ASCRS Ophthalmic Services Corp. EBMD. Start with central laser (4–6 μm). Move reticle toward the limbus and treat the outer cornea, trying to get 4–6 μm to all areas for the cornea. Source (all): David Hardten, MD