EyeWorld Asia-Pacific June 2017 Issue

June 2017 30 EWAP SECONDARY FEATURE Trimoxi and $25 for TriMoxiVanc. We also save a significant amount of time counseling patients about drops, in phone calls from pharmacies, for substitutions, and so on. On the service side, we save valuable time and energy,” he said. Intracameral According to Dr. Mah, injecting postoperative meds is a smart, proactive move toward taking the responsibility out of the patient’s hands and into his own. “I think there are several reasons that surgeons are reacting negatively toward drops today, and trying to take that responsibility from the patient. One big reason is compliance. You have no idea what the patient is doing, if he has picked up the medication(s), picked up the prescribed medication(s), if he is applying it correctly, or has the help he needs to take the meds. These unknowns strongly influence surgical outcomes, and the surgeon should have more control here,” Dr. Mah said. In addition, “efficacy is another reason to consider new drug delivery methods like the Imprimis or Dextenza [Ocular Therapeutix, Bedford, Massachusetts] or other types of ‘dropless’ cataract surgery such as compounded dexamethasone- moxifloxacin [Ocular Science, Manhattan Beach, Calif.] which is what I have actually been using. I apply meds intracamerally. There is voluminous medical literature supporting the intracameral method of prophylaxis including prospective clinical trials. It brings into question the topical method of prophylaxis, where the efficacy of these medications is out of our hands. Why not use something that can be more efficacious and takes outcomes issues away from the patient?” he said. Dr. Mah opts for an intracameral approach to apply postoperative prophylactic meds, choosing to avoid the transzonular and pars plana approaches. Although TriMoxi and TriMoxiVanc offer the all-in-one approach, there are a few reasons he prefers not to use it. “Firstly, I am in favor of avoiding intraocular vancomycin until the incidence and association of vancomycin with hemorrhagic occlusive retinal vasculitis (HORV) is elucidated and debunked. As for triamcinolone, it is only usable in the vitreous, which I do not feel is necessary. It has a long half-life, which can be a big problem in steroid responders. Also, as a suspension, triamcinolone leaves vision blurry for at least a day or two, or longer, even if everything else goes perfectly. I prefer to assess my patient’s vision right after surgery, and patients appreciate immediate improved vision,” he said. Dr. Mah also noted that not all patients can afford to have poor vision for days after surgery. Dr. Mah explained that knowing the effective lens position immediately following surgery was a key factor in managing premium patients (i.e., those primarily electing to have surgery with largely non-reimbursable products). He thinks that manipulating the zonules by injecting something transzonularly can potentially affect the effective lens position and the determination of the best possible postrefractive outcomes. He elucidated that putting something into the anterior vitreous has anecdotally affected the potential space between the posterior capsule and anterior hyaloid face, altering the desired refractive outcome by causing a myopic result of several Crystalens or Trulign cases, where the posterior capsule was pushed forward due to medication placed transzonularly into the potential space, pushing the implant lens forward. “My choice is moxifloxacin with dexamethasone (Ocular Science), which I inject directly into the anterior chamber after cataract surgery. The combination consists of 0.5% moxifloxacin and 0.1% dexamethasone, giving 0.15 cg of this mix. What gets into the eye would be approximately 750 micrograms of the moxifloxacin and 150 micrograms of the dexamethasone. After I’ve taken the cataract out, I check my incisions like I normally would to make sure the incisions are water- tight. Then I use a 1cc syringe and an AC cannula (27 or 30 gauge) through the paracentseis site, and go right underneath the anterior capsule and inject,” he said. According to Dr. Mah, dexamethasone is a preferable choice over triamcinolone due to its shorter half-life of 7 to 8 days, voluminous data of use in ophthalmology compared to all other steroids, and clarity of the preparation. As most cataract patients would not require steroids after surgery for any longer than 2 weeks, dexamethasone would very likely be sufficient coverage. A huge advantage is that compared to the murkiness of triamcinolone that obscures early postoperative vision and requires transzonular or pars plana application, dexamethasone is clear and can be left in the anterior chamber without concern—even in glaucoma patients. When he was at the University of Pittsburgh, Dr. Mah’s colleagues published a paper with higher amounts of intracameral dexamethasone in glaucoma patients being safe and effective following routine cataract surgery. Dr. Mah thinks that anterior segment surgeons who do not normally deal closely with the vitreous might feel uncomfortable and avoid vitreous manipulations if possible. Surgeons unaccustomed to working beyond the anterior segment might feel uncomfortable trying to perform a transzonular or pars plana drug delivery approach, which may invalidate TriMoxi from their list of options, while intracameral application would be more attractive to them. “Injecting into the anterior capsule is not challenging for anterior segment surgeons. That’s just my own assessment. Obviously there are surgeons out there successfully using TriMoxi and other formulations using vitreous approaches which is great, but for me, I just don’t feel as comfortable and I’m glad I don’t have to learn a new technique or disturb the zonules or vitreous,” Dr. Mah said. EWAP Editors’ note: Dr. Galloway has financial interests with Imprimis Pharmaceuticals. Dr. Mah has financial interests with Bausch + Lomb (Ridgewood, New Jersey), Novartis (Basel, Switzerland), Ocular Science (Manhattan Beach, California), and PolyActiva (Melbourne, Australia). Contact information Galloway: eyeguy@frontiernet.net Mah: mah.francis@scrippshealth.org Going – from page 29