EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/194331
October 2013 EW NEWS & OPINION 29 Pharmaceutical focus Update on lid margin disease by Maxine Lipner EyeWorld Senior Contributing Writer Latest on diagnosis and treatment L id margin disease should be front and center for many ophthalmic practitioners. "It is the most common disease perhaps in all of medicine," said Steven L. Maskin, MD, Dry Eye and Cornea Treatment Center, Tampa, Fla. Scheffer CG Tseng, MD, director, Ocular Surface Center, Miami; medical director, Ocular Surface Research & Education Foundation, Miami; and chief scientific officer, Tissue Tech, Miami, agreed. Dr. Tseng pegs blepharitis as the most common eye disease encountered by ophthalmologists, and notes that the Demodex mite is the usual cause here. There are two species of this parasite, Demodex folliculorum and Demodex brevis, Dr. Tseng explained, adding the folliculorum is on the outside of eyelash follicles and the brevis on the inside of the sebaceous glands next to these. "The Demodex lay their eggs on oil, they eat oil, and they live on oil," Dr. Tseng said. Hallmark signs Burning and irritation are commonly associated with Demodex but are certainly not exclusive to the condition, Dr. Tseng said. Cylindrical dandruff at the root of eyelashes is the hallmark sign. However, this should not be confused with crusting caused by other things such as dried medication or a coating of mucous, he added. Dr. Maskin observed that Demodex usually, but not always, is accompanied by cylindrical dandruff. "If you don't see a cylindrical deposit it doesn't mean that the patient doesn't have Demodex deeper within the glands—they like to feed on the sebaceous oil," he said. "In my practice if I have a patient with chronic lid inflammation who comes to me for help I'll epilate and look for the Demodex under a microscope." To establish that Demodex mites are indeed causing the problems, Dr. Tseng suggested pulling and examining lashes under the microscope. "We also recommend people count the mites to establish the amount of infestation," he said. Cylindrical dandruff due to Demodex mites Source: Scheffer CG Tseng, MD New treatment options Once Demodex is determined to be the cause, next comes treatment. "In the early days about 15 or 20 years ago people treated blepharitis with general hygiene, lid scrubs, and baby shampoo," Dr. Tseng said, adding some also used an antibiotic and steroid combination. Currently, however, tea tree oil is considered the go-to treatment. Dr. Tseng found that 4-Terpineol is the active component here. "It can kill mites and also has other antimicrobial activity," he said. For patients with Demodex blepharitis, Dr. Tseng recommended Cliradex (Bio-Tissue, Doral, Fla.), which contains 4-Terpineol. "When we apply Cliradex we try to soak but not rub the area," Dr. Tseng said. "Generally we ask patients to close the eye but not squint, and to relax and elevate the brow." He recommended moving from one location to the other with the medication allowing the fluid to be absorbed into the area and then to air dry rather than blotting it away. In addition to the mites, there may be a bacterial component at work, Dr. Tseng said. He cited research published in the May 2010 issue of Ophthalmology, which he conducted with Kevin Kavanagh, BSc, PhD, of the National University of Ireland, Maynooth, which showed a correlation between ocular Demodex mites and reactivity to Meibomian gland obstruction with released sequestered meibum through orifice after probing Source: Steven L. Maskin, MD Bacillus bacteria in those with facial rosacea. This bacterium lives in the intestines of Demodex mites, and the protein that they secrete is very inflammatory when they die, Dr. Tseng explained, adding that rosacea is the worst form of blepharitis. While it was known that there is a strong correlation between Demodex mites and rosacea, this research showed that patients developed antibodies against the Bacillus bacteria and furthermore had strong inflammatory reactions to it, he said. While this may justify using antibiotics in Demodex cases, Dr. Tseng finds that there can be difficulties with this. "The problem here is that oral medication as well as topical medication will be very hard to get into the intestine of the mites," he said. However, since the mites are a carrier of the bacteria, killing the Demodex with Cliradex, he believes, is indirectly an effective way to control the bacterial invasion. In addition to Demodex mites, Dr. Maskin observed that Staph bacteria are a common cause of anterior blepharitis. With such bacteria he uses antibiotic treatment. However, drops are not recommended. "The proper way to treat anterior blepharitis is not with drops," he said. "It's with ointment because of the residence time of therapy at the site of infection. You put a drop in the eye and it's gone in five minutes or so, continued on page 30