A New lOP-Lowering Medication
By Leo Semes, OD, FAAO
It has been awhile since any new topical intraocular pressure (IOP)-lowering medications were approved by the U.S. Food and Drug Administration (FDA). On Feb. 10, 2012, the FDA approved Zioptan (0.0015% tafluprost, Merck). While this medication has been available elsewhere in the world for several years, it is new to the United States and unique in its current, non-preserved formulation. Consequently, it is packaged in unit-dose format. There are 30 containers per package intended for 30-day use. It is indicated for lowering IOP in those diagnosed with ocular hypertension or open-angle glaucoma.
The application for this unique formulation may seem limited. In fact, that is the case. The following is a personal perspective based on my short-term experience.
The first patient is a 92-year-old African-American female. She has been treated in our clinic for more than 30 years with a variety of topical medications. Interestingly, she is phakic and correctable to 20/25 in each eye. Her anterior segment was remarkable for conjunctivochalasis but with only minimal evidence of fluorescein staining. She was currently using a prostaglandin analog (PGA) each evening and a combination drop in the morning. The IOP had been measured between 16mmHg and 19mmHg over the past several visits. Evidence of visual field and optic disc progression suggested the need to change strategy. Options included a different class of medication or switching to a novel PGA.
With the availability of a nonpreserved PGA, we decided to make it part of her regimen. On return, two weeks after initiating Zioptan therapy, the IOP was 13mmHg in each eye. One month later the substitution of tafluprost maintained IOP at 13mmHg. Indications for the non-preserved formulation included the condition of the ocular surface. This has become an emerging area for concern among patients who need IOP-lowering therapy. Chronic application of benzalkonium chloride (BAK) to the ocular surface may be detrimental (Pflugfelder and Baudouin, 2011). Minimizing it, especially in chronic settings, deserves consideration.
The next example involves a 78-year-old Caucasian female who had been a subject in a dryeye study many years ago. She had been seen elsewhere for years and returned to address a “dry eye” complaint. Complicating her situation is a Sjögren's syndrome diagnosis. The best-corrected VA was 20/25 in each eye, and her cornea revealed significant stippling with fluorescein. The tear break-up time was <5 seconds in the right eye and almost immediate in the left eye.
Following a short course of topical steroids and frequent tear supplement applications, the patient had some relief of ocular signs. Symptomatic relief was minimal but noticeable. She also had received a glaucoma diagnosis and was being treated with 0.2% brimonidine (generic preserved with BAK) three times per day. With her consent, we initiated Zioptan q.h.s. Her initial IOP with brimonidine was 22mmHg, which, with her moderate opticnerve damage, we felt was too high. We established a target pressure of 14mmHg to 16mmHg and asked the patient to discontinue the brimonidine. She measured IOP of 13mmHg in each eye at the initial evaluation two weeks after starting the new regimen. We are now focusing on re-establishing the ocular surface integrity while minimizing further optic nerve damage.
Consider This Option
With the concomitant presence of ocular surface changes and elevated IOP, patients deserve the consideration of amelioration with direct treatment as well as omitting any possible confounding influences. The non-preserved prostaglandin analog Zioptan offers the latter. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #201.
|Dr. Semes is a professor of optometry at the UAB School of Optometry. He is a consultant or advisor to Alcon, Allergan, Optovue, and Zeiss.|