Therapeutic options in ophthalmic market expand

Atlanta-Keeping up with developments in ophthalmic therapy could be a full-time job in itself, as new products are constantly tested and introduced, reformulated, given expanded indications, or withdrawn from the market. Tammy P. Than, MS, OD, FAAO, has saved doctors time by giving them an update on a number of these changes during her presentation at the annual SECO meeting.

Anti-infective update

Several drugs for the treatment of adenoviral conjunctivitis are in clinical trials, some with different mechanisms of action than customarily used. These include a combination of 0.1% dexamethasone and 0.4% povidone-iodine (FST-100, Foresight Biotherapeutics); an aganocide compound based on the chemical structures of naturally occurring antimicrobial agents (AL-46383A [N-chlorotaurine] NovaBay Pharmaceuticals); and a metallo-organic compound (Doxovir, OPKO Health), which has both antiviral and anti-inflammatory properties.

Bacterial conjunctivitis therapies

Among currently marketed therapies for bacterial conjunctivitis, a new formulation of the topical fluoroquinolone moxifloxacin 0.5% (Moxeza, Alcon) was approved by the FDA last fall. This agent has the same concentration as the original drug (Vigamox), but is contained in a different vehicle, xanthan gum. When this drop hits the eye, it thickens and stays on the eye longer. It is labeled for B.I.D. rather than T.I.D. use. In addition, unlike other fluoroquinolones, topical fluoroquinolone moxifloxacin 0.5% is approved for use in infants ≥ 4 months old.

A higher concentration of gatifloxacin ophthalmic solution 0.5% (Zymaxid, Allergan) was also approved last year. Because it is a stronger solution, patients may need to use it less frequently. It is labeled for B.I.D. to Q.I.D. use on days 2 to 7 of treatment.

Dr. Than also provided an update on the work of the Ocular Tracking Resistance in U.S. Today (Ocular TRUST), a longitudinal nationwide antimicrobial susceptibility surveillance program specific to ocular isolates. Reports from this group provide further evidence of increasing resistance to ophthalmic antibiotics, including widely used fluoroquinolones.

The program's tests so far have shown that methicillin-resistant Staphylococcus aureus is susceptible only to trimethoprim (available in an ophthalmic formulation as the combination agent polymyxin B sulfate and trimethoprim sulfate, [Polytrim, Allergan]) and to a lesser extent, tobramycin.

The Ocular Trust also found that all antimicrobials are less active against methicillin-resistant coagulase-negative staphylococci (CNS) than methicillin-susceptible CNS, and that macrolides, such as azithromycin, are associated with lower in vitro susceptibility rates compared with the fluoroquinolones.

One of the most frequent reasons for visits to the optometrist is for the management of ocular surface disease. Sodium fluorescein (1% ) and lissamine green (0.5%) (Fluramene, Noble Vision Group) was introduced in 2010 as a diagnostic tool for simultaneous evaluation of the cornea and conjunctiva. This one-step process may be more convenient for patients and clinicians, Dr. Than said. The product is available only from EyeSupply USA.