Eyeworld

57 EW CORNEA July 2015 Contact information Mah: mah.francis@scrippshealth.org Tu: etu@uic.edu get the medication into the cornea in fungal keratitis cases, you need to almost debride the epithelium to get the drugs through the stroma. When he mentioned this to Karl Stonecipher, MD, Dr. Stonecipher took it a step further and performed PTK on patients first before instilling medication in a couple of cases. "He got really fast resolution—much faster than without the PTK," Dr. Mah said. The use of crosslinking is an- other possibility, Dr. Tu said, adding that this, however, does have its limitations. "One of the issues with corneal crosslinking is that with the standard protocols it's clear that there's not much of an effect beyond the anterior one-third of the cornea," he said. Unfortunately, with fungal keratitis many times the infection has already reached the deeper parts of the stroma. Still, crosslinking may be helpful as an adjunctive treatment and in more superficial cases, Dr. Tu said. Deciding when to move onto corneal surgery requires some judg- ment. "As far as timing is concerned, you don't want to do it too early, but you don't want to do it too late," Dr. Tu said. "If you have an organism or an infection that is not responding to any of your medical treatments and seems to be extend- ing into an area you can't easily transplant, it's best to consider a transplant at that point." When surgery is needed, Dr. Tu mainly performs penetrating keratoplasty. He tends to prefer this since there may be some extension into the deeper layers that he can't see. However, many studies have also shown that anterior lamellar keratoplasty can be very successful in these patients. So he does not rule this out in cases where practitioners can be reasonably sure that the infection doesn't involve Descemet's membrane. Going forward, one new modal- ity that Dr. Tu thinks may be a game changer is the use of intrastromal injection of antifungal medications. This enables practitioners to inject aqueous soluble agents such as amphotericin B and voriconazole directly into the corneal stroma. The advantage here is it delivers very high levels of the antifungal into the cornea that last anywhere from 5 to 7 days, he said. "That has been shown to be very effective even in patients who have deeper filamen- tous fungal keratitis," he said. EW Editors' note: Dr. Mah has financial in- terests with Alcon (Fort Worth, Texas). Dr. Tu has no financial interests related to his comments. K1-5696 (17mm blades) K1-5697 (13mm blades) K3-2440 pointed K3-2442 blunted Double-X Speculums Incision Spatulas Nucleus Splitters Eric Donnenfeld, MD of Rockville Centre, NY Tarek Badawy, MD of Cairo, Egypt K3-2448 for use in the right hand K3-2449 for use in the left hand patent pending Ralph Chu, MD of Bloomington, MN 973-989-1600 • 800-225-1195 • www.katena.com ® This speculum combines arms that open in a parallel fashion with flattened, vaulted blades for the reduction of external pressure on the globe. This significantly aids in docking the laser to the eye. K3-2460 Instrumentation Two versions of this 0.3mm wide incision opening spatula are available. One has a pointed tip (K3-2440) for surgeons who occasionally find incisions challenging to find and open, while the other (K3-2442) has a blunt tip for entering these incisions. This double ended instrument features the blunted 0.3mm incision spatula on one end and a 2mm wide blunt, keratome-shape spatula for opening the main incision on the other. The ultra thin tips on these splitters are designed to fit into the laser created grooves in the nucleus to safely fragment down to the posterior plate. One instrument can be used in conjunction with the phaco tip or two through opposing incisions in a bimanual technique.

• Cover