EyeWorld India June 2020 Issue

CORNEA EWAP JUNE 2020 41 by Liz Hillman EyeWorld Editorial Co-Director AT A GLANCE • Crosslinking is meant to strengthen a weakened, bulging cornea, stopping progression of keratoconus. It doesn’t necessarily improve vision. • Combining crosslinking with therapeutic refractive procedures can enhance a patient’s ability to wear soft contact lenses, improve visual acuity with glasses, or even improve uncorrected visual acuity. • Therapeutic refractive options include intrastromal ring segments and topography- guided PRK. Contact information Hersch: phersh@vision-institute.com Loden: lodenmd@lodenvision.com Rebenitsch: dr.luke@clearsight.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. C rosslinking, while therapeutic to stop progression of keratoconus and corneal ectasia, leaves something to be desired by patients in terms of refractive outcomes. As such, cornea specialists have been pairing it with other devices and procedures, allowing patients to get the best of both worlds: a strengthened, stable cornea and improved visual acuity. Luke Rebenitsch, MD, shared his practice’s algorithm for adjunct treatments to crosslinking: 1. For patients with early ectasia and with CDVA close to 20/20, they do crosslinking alone. 2. v ̅iÀi ˆÃ È}˜ˆwV>˜Ì i«ˆÌ…iˆ> remodeling around the cone seen on epithelium mapping >à Üi >à ÃÕvwVˆi˜Ì ÀiÈ`Õ> stroma, they use PTK to reduce the cone, making sure to Ài“œÛi ˜œ “œÀi ̅>˜ xä ù“° 3. v ̅iÀi ˆÃ ˜œ È}˜ˆwV>˜Ì epithelial remodeling, they consider topography-guided PRK, removing no more than xä ù“° 4. v ̅iÀi ˆÃ È}˜ˆwV>˜Ì Vœ“> across the pupil and CDVA <20/40, they consider a single intrastromal ring segment or asymmetric segments. Crosslinking alone “The goal of crosslinking is to stabilize the corneal biomechanics in order to prevent progression of keratoconus,” said Peter Hersh, MD. “It does …>Ûi ̅i Li˜iwVˆ> ivviVÌ Ì…>Ì there is a little bit of decrease in the cone—on average about a diopter and a half—but the goal is to stabilize the cornea.” Dr. Rebenitsch said he recommends crosslinking vœÀ «>̈i˜Ìà ܈̅Vœ˜wÀ“i` keratoconus. “As keratoconus manifests as early as your adolescent years, we are crosslinking earlier and earlier before further damage to the cornea is done,” Dr. Rebenitsch said. “Historically, it was thought that keratoconus progression slowed or even stopped later in life. We have good data to show that is not always the case, so we use age as just one factor in evaluating for crosslinking. In general, though, the earlier we can catch it the better.” James Loden, MD, offered a similar sentiment, saying he is a little more aggressive in recommending crosslinking to patients with keratoconus. The current FDA-approved protocol requires documentation of keratoconus progression and uses an epithelium- œvv] Î䇓ˆ˜ÕÌi ÀˆLœy>ۈ˜ soak, followed by 30-minute irradiation from a UV-A light using the Avedro (recently acquired by Glaukos) system. Dr. Loden, however, uses a non-FDA approved device, compounded ÀˆLœy>ۈ˜] >˜` œvviÀà ̅i procedure to patients on a cash- pay basis. “I think the ideal time to treat > «>̈i˜Ì ˆÃ ܅i˜ ˆÌ wÀÃÌ Ã…œÜà ի in their teens or early 20s. That’s where I think the real emphasis needs to be, and I’m coming Crosslinking, combo procedures for refractive outcomes in keratoconus from the perspective that I have keratoconus. I’ve been crosslinked,” Dr. Loden said, explaining that his procedure was done with the same non- FDA approved system. “I would give anything if we had crosslinking when I was 22 years old because mine progressed to the point where I can see 20/20 with glasses but it’s blurry. Gas permeable contact lenses are uncomfortable to wear but they give crisp vision. I wish I had the opportunity to receive crosslinking back then; we could have arrested the disease process in its very early stages.” Waiting to show progression, Dr. Loden said, is “dereliction of duty.” “It’s like saying, we don’t want to treat your cancer until you’re having a symptom from it,” Dr. Loden said, adding that almost all cases of keratoconus will progress. It’s just a question of when and how much. Two things that Dr. Rebenitsch said have been “game changers” in decreasing pain and increasing the speed of epithelialization is doing an epi-Bowman keratectomy (EBK) for epithelium removal and using Regener-Eyes in the postoperative period. If an eye was having delayed epithelial healing, Dr. Loden said he would pull steroid drops. “Steroids will impede corneal epithelial healing. The most important thing to prevent a haze reaction, whether it’s with PRK, PRK with crosslinking combined, or crosslinking alone, is to get the epithelium healed as quickly as