Eyeworld

82 | EYEWORLD | APRIL 2023 C ORNEA Contact Beckman: kenbeckman22@aol.com Majmudar: pamajmudar@yahoo.com "In some infections where cultures remain negative and they are not responding to treat- ment, if the infection is very deep, I may take a suture and pass it through the stroma, through the cornea mid-depth, not into the anterior chamber … so that it tracks deep enough so that I might get a better specimen and use that to culture," he said. While Gram stains can come back within a day, bacterial cultures can take 3–4 days, and fungal cultures can take a month. Dr. Majmudar pointed out that there are several labs that do PCR testing on a number of pathogens with a swab, rather than culture plates, which he said makes it relatively easy for any practice to do. Treating Dr. Beckman will usually start patients on ag- gressive antibiotics, a fourth-generation quino- lone or fortified antibiotic drops, even if the culture hasn't come back with a specific patho- gen yet. Some patients, depending on severity, will be instructed to use this every hour. Also depending on severity, patients are followed up within the clinic every day or two. Once the ep- ithelium heals, Dr. Beckman said he'll cut back on treatment but will keep them on drops for a couple of weeks. Antibiotics may be tailored more specifically once the culture comes back. If the culture comes back as a fungus, he'll begin an antifungal but will also keep them on the antibiotic. If quinolone monotherapy was used initially and isn't effective, Dr. Beckman said he'll move on to a combination of fortified antibiotics. Dr. Majmudar said the most commonly pre- scribed antibiotic for corneal ulcers is moxiflox- acin, but it has limited gram-negative cover- age. He will start a patient on broad-spectrum fortified antibiotics, including fortified cefazolin or vancomycin and fortified tobramycin. Fungal treatment is dependent on whether it is filamen- tous or yeast. He said as a primary intervention he would use voriconazole or natamycin for filamentous fungal infections and amphotericin B for yeast infections. Dr. Beckman said he does not typically use steroids, though he thinks a lot of other phy- sicians do. Steroid use for corneal ulcers has been debated. The Steroids for Corneal Ulcers Trial found that "adjunctive topical corticoste- roid therapy may be associated with improved long-term clinical outcomes in bacterial corneal ulcers not caused by Nocardia species." 1 "If one is going to use a steroid, you want to see there is clear improvement with antibiot- ics before you do it. Those signs would be the epithelium healing, the infiltrate consolidating, any inflammation going away, the anterior chamber (if there are cells) resolving, improved redness, improved comfort, and it really helps if you identified the bug on the original cultures," Dr. Beckman said. Dr. Majmudar also said he likes to see some sort of clinical progress before starting steroids, but he'll use them after 3–4 days in a compliant patient. continued from page 80 What about crosslinking? Over the last few years there have been studies and reports of crosslinking as a possible therapy for corneal ulcers caused by fungal infections. While these results have been "generally positive," Dr. Majmudar said, they're mixed. And it's expensive. In the U.S., for exam- ple, Dr. Beckman said crosslinking for this indication would not be covered by insurance, and the riboflavin alone costs several thousand dollars. "It also doesn't seem necessary. For a fungal infection, we have a lot of anti- fungals out there and they may do well. I'm not convinced from the data that it would be better. It seems like a last resort to potentially avoid a transplant." On that note, Dr. Majmudar said that he thinks it may play a role in recalcitrant ulcers that would otherwise require a corneal transplant.

• Blank Page
• Blank Page (1)