EyeWorld Asia-Pacific December 2012 Issue

52 September 2012 EWAP MEETING REPORTER D ce ber 2012 stabilizers, immunotherapy, and corticosteroids. Each agent has its own set of limitations, mostly inherent in their mode of action— antihistamines reduce itching but not redness, vasoconstrictors reduce redness but not itching, and corticosteroids bear the stigma of their safety profiles. This is unfortunate, because, said Edward J. Holland, MD , Cincinnati, Ohio, USA, they are the most effective anti- inflammatory agents, offering a broad spectrum of activity that provides the most comprehensive coverage of the inflammatory cascade of any available agent. These agents suppress the migration of polymorphonuclear leukocytes (PMNs) and the reparative processes and functions of fibroblasts, reverse enhanced capillary permeability, and stabilize lysosomes. Ophthalmologists have come to fear the elevation of IOP, risk of formation of posterior subcapsular cataracts, aggravation of infectious disease states, and the delay in the normal course of healing that has been associated with the use of corticosteroids. This, said Dr. Holland, has resulted in the suboptimal treatment of active disease and the failure to prevent recurrent disease. The solution may come in the form of the first and, to date, only ester steroid: loteprednol etabonate. Loteprednol, said Dr. Holland, has been shown to be 10 times more lipophilic and have 4.3 times the glucocorticoid receptor binding affinity of dexamethasone— characteristics that significantly alter the safety profile of the drug. While as effective as the current “gold standard” for steroid therapy—prednisolone—Dr. Holland said that loteprednol has significantly less IOP response, making it ideal for long-term use. Ophthalmologists, said Dr. Holland, need to rethink their aversion to corticosteroids, listing dry eye inflammation, meibomian gland disease, chronic conjunctival inflammation, immune stromal keratitis, and even adenoviral ocular infection as indications for corticosteroid use. Corticosteroids, he said, are the most effective way of avoiding the corneal scarring and pain that are sure to result from undertreating chronic inflammatory eye conditions, complications that are at least commensurate—and also far more likely to occur—than the cataract, glaucoma, and steroid dependence that can be avoided through appropriate and judicious use of available agents. Engineered against resist- ance? In managing keratitis, said John D. Sheppard, MD , Norfolk, Va., ophthalmologists should consider some important associations: pseudomonas for contact lens ulcers, MRSA/MRSE for at-risk patients, protozoans for unresponsive cases. Basically, he said, it is often best to expect the worst possible bugs when deciding on treatment. The “worst” includes consideration for growing microbial resistance around the world. There is, said Dr. Sheppard, a growing population of baseline methicillin-ciprofloxacin resistant bugs. At the rate microbial resistance is rising, it is entirely possible that all bugs are methicillin resistant within the decade. Amid these rising resistance rates, Dr. Sheppard touted a new option for antimicrobial treatment, the first chlorofluoroquinolone: besifloxacin. Bausch + Lomb’s formulation of the drug, Besivance (besifloxacin ophthalmic solution 0.6%, Rochester, NY, USA) delivers the drug in a mucoadhesive vehicle of DuraSite, which helps keep the drug on the eye. The molecular characteristics that make besifloxacin what it is—including a chloride in its structure—mean the drug delivers the most balanced inhibition of microbial DNA gyrase and topoisomerase II action, for a lowered probability of allowing mutant survivors to develop resistance. In 696 conjunctival isolates, he said, he has seen no incidence of resistance to besifloxacin. The drug, he said, offers potent, bactericidal coverage over a broad spectrum of microbes that includes resistant strains. Safety with contact lenses Given the ubiquity of contact lens use, the incidence of contact lens-related microbial keratitis— that such infections should occur at all—should be of concern to ophthalmologists. Fiona Jane Stapleton, PhD , Sydney, Australia, looked into the various risk factors affecting the incidence of keratitis. Among the modifiable risk factors Dr. Stapleton examined, she found that using contact lenses 6 to 7 days a week resulted in a six- fold increase in risk; other factors include extended wear, internet purchase, occasional overnight use, poor case hygiene, smoking, daily disposable contact lens use, and failure to hand wash lenses. Nonmodifiable risk factors include the initial 6-month extended wear of contact lenses, socioeconomic factors, age less than 49 years, hypermetropia, and male gender. Daily disposable lens use, she said, had the curious effect of increasing the risk of microbial keratitis, but lowering the incidence of severe disease compared with planned replacement daily wear—50% against the 70% seen in patients using the latter. Dr. Stapleton concluded that incidence has not changed with newer contact lenses, contact lens solutions, and modalities, but that it is possible to limit the severity of the disease by favoring daily disposable lenses and avoiding delay in treatment. Contact lens and lens case hygiene being risk factors, Dr. Stapleton emphasized the need for ophthalmologists to work with industry, regulators, and researchers to establish a ACS - from page 51