EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/220233
November 2013 Pharmaceutical corner DisCoVisc® Ophthalmic Viscosurgical Device (Sodium Chondroitin Sulfate – Sodium Hyaluronate). Caution: Federal (USA) law restricts this device to sale by or on the order of a physician. There's no fun in fungal keratitis Description: DisCoVisc® Ophthalmic Viscosurgical Device has an intermediate cohesive/dispersive index (CDI) and can best be described as the first viscous dispersive viscoelastic and is optimized for the entire surgical procedure. Indications: DisCoVisc® Ophthalmic Viscosurgical Device is indicated for use during surgery in the anterior segment of the eye. It is designed to create and maintain space, to protect the corneal endothelium and other intraocular tissues and to manipulate tissues during surgery. It may also be used to coat intraocular lenses and instruments during cataract extraction and IOL insertion. by Maxine Lipner EyeWorld Senior Contributing Writer Diagnostic and treatment strategies for corneal fungal infections Warnings: Failure to follow assembly instructions or use of an alternate cannula may result in cannula detachment and potential patient injury. A patient who while gardening collided with a rose bush comes in a day or two later complaining of discomfort and decreased vision. Chances are it's a fungal infection, said Eduardo C. Alfonso, MD, chairman and director of the Bascom Palmer Eye Institute, Miami. Still, determining this for certain and successfully treating such infections may be anything but child's play. "The history and examining the patient for physical findings of the cornea are extremely important because this will provide us with signs and symptoms that can make us think of the possibility of fungal keratitis," Dr. Alfonso said, adding that a patient who has had ocular trauma involving plants is at a much higher risk of fungal infection, as are contact lens wearers, users of steroid drops, and those who suffer from ocular disease or who have recently undergone surgery. Diagnostic jungle gym To clinch the diagnosis, Dr. Alfonso relies on the microbiology laboratory, submitting smears and cultures. "Then we do other photographic diagnostic testing like OCT to see what the involvement of the corneal tissue is and confocal microscopy of the cornea, which helps us see if this has organisms that resemble fungi," he said. Elmer Y. Tu, MD, professor of clinical ophthalmology, University of Illinois Eye and Ear Infirmary, Chicago, also relies on such tests. Dr. Tu observed that the majority of unusual infections such as molds have a tendency to be filamentous. "They do have a characteristic appearance on confocal microscopy," Dr. Tu said. "They're linear and they look like tree branches—the majority are septate, with interruptions in those branches." If the appearance of fungi can be rapidly confirmed by confocal microscopy and the smear, Dr. Tu will immediately start the patient on antifungals. "However, if there is some question, we always err on the side of treating it as a bacterial infec- Precautions: Precautions are limited to those normally associated with the surgical procedure being performed. Although sodium hyaluronate and sodium chondroitin sulfate are highly purified biological polymers, the physician should be aware of the potential allergic risks inherent in the use of any biological material. Adverse Reactions: DisCoVisc® Ophthalmic Viscosurgical Device was very well tolerated in nonclinical and clinical studies. A transient rise in intraocular pressure in the early postoperative period may be expected due to the presence of sodium hyaluronate, which has been shown to effect such a rise. It is therefore recommended that DisCoVisc® OVD be removed from the anterior chamber by thorough irrigation and/or aspiration at the end of surgery to minimize postoperative IOP increases. Do not overfill anterior chamber. ATTENTION: Reference the Physician Labeling/Directions for Use for a complete listing of indications, warnings and precautions. U.S. Patent Nos. 5,273,056; 5,876,379 and 6,051,560. Aspergillus corneal ulcer Source: Bascom Palmer Eye Institute tion because those have a tendency to be more rapidly progressive and there are irreversible consequences visually," he said. Meanwhile, if the history is suggestive of fungal keratitis, Dr. Alfonso looks carefully at confocal microscopy, takes cultures, and keeps a watchful eye on the patient. "I'll start the patient initially on broad-spectrum antibacterial treatment," he said, emphasizing that he continues to bring the patient back daily to see if anything is growing and the clinical findings are changing. If in 48 to 72 hours he finds that the condition is not improving with antibiotics, then Dr. Alfonso will empirically treat patients with antifungal medications. "You have to remember that even with fungal keratitis we only get positive cultural results in about 50% of cases," he said. In cases where the infection appears to be Fusarium, Dr. Alfonso uses natamycin (Natacyn Alcon, Fort Worth, Texas), the only commercially available preparation, which he finds is a very good overall antifungal. For other cases he relies on compounded preparations. "We can use any other antifungal preparation for oral, skin, systemic, or intravenous use and make that into a drop form," he said. Treatment swings Dr. Tu noted that there have been some shifts over time in medication that have proven valuable. He pointed to the Fusarium mold outbreak, which occurred in contact lenses wearers in the U.S. around 2006. At that time, topical, compounded voriconazole drops became popular. "Recent studies, though, indicate that it is not necessarily superior to what we have right now, which is natamycin," he said. Dr. Tu usually reserves the voriconazole for resistant infections. In his view, voriconazole's greatest strength may reside in a new intracorneal injection technique being used in the United States and in the Pacific Rim and Asia. "It's not appropriate for every single fungal keratitis case, but those that are resistant have some dramatic responses," Dr. Tu noted, adding that this has appeal on two levels. "You get high levels in the cornea without the systemic side effects of using oral medications, and you also have significantly less expense," he said. While most of the newer oral antifungals cost a couple of thousand dollars per month, the use of intrastromal injection is a fraction of that, Dr. Tu said. He views posaconazole (Noxafil, Merck, Whitehouse Station, N.J.) as another drug to consider in resistant cases. "This is also something that we've used orally and topically," he said. There's a new class of antifungal medications called the echinocandins that affect mold, fungus, and yeast, Dr. Tu said. This, he explains, interferes with a portion of the cell wall and affects a building enzyme not found in humans. "These, at least in theory, have a better tolerability profile," he said. "The only DUOVISC® Viscoelastic System is designed to give two viscoelastic materials with different physico-chemical properties that can be used differently and/or sequentially to perform specific tasks during a cataract procedure. DUOVISC® Viscoelastic System consists of VISCOAT® Ophthalmic Viscosurgical Device and PROVISC® Ophthalmic Viscosurgical Device. CAUTION: Federal law restricts this device to sale by or on the order of a physician. VISCOAT® OVD (Sodium Chondroitin Sulfate – Sodium Hyaluronate) Ophthalmic Viscosurgical Device INDICATIONS: VISCOAT® OVD is indicated for use as an ophthalmic surgical aid in anterior segment procedures including cataract extraction and intraocular lens (IOL) implantation. Viscoat maintains a deep anterior chamber during anterior segment surgeries, enhances visualization during the surgical procedure, and protects the corneal endothelium and other ocular tissues. The viscoelasticity of the solution maintains the normal position of the vitreous face and prevents formation of a flat chamber during surgery. WARNINGS: Failure to follow assembly instructions or use of an alternate cannula may result in cannula detachment and potential patient injury. PRECAUTIONS: Precautions are limited to those normally associated with the surgical procedure being performed. Although sodium hyaluronate and sodium chondroitin sulfate are highly purified biological polymers, the physician should be aware of the potential allergic risks inherent in the use of any biological material. ADVERSE REACTIONS: VISCOAT® OVD has been extremely well tolerated in human and animal studies. A transient rise in intraocular pressure in the early postoperative period may be expected due to the presence of sodium hyaluronate, which has been shown to effect such a rise. It is therefore recommended that Viscoat be removed from the anterior chamber by thorough irrigation and/or aspiration at the end of surgery to minimize postoperative IOP increases. Do not overfill anterior chamber. ATTENTION: Reference the Physician Labeling/Directions for Use for a complete listing of indications, warnings and precautions. PROVISC® OVD (Sodium Hyaluronate) Ophthalmic Viscosurgical Device INDICATIONS: ProVisc® OVD is indicated for use as an ophthalmic surgical aid in the anterior segment during cataract extraction and intraocular lens (IOL) implantation. Ophthalmic viscoelastics serve to maintain a deep anterior chamber during anterior segment surgery allowing reduced trauma to the corneal endothelium and surrounding ocular tissues. They help push back the vitreous face and prevent formation of a flat chamber during surgery. PRECAUTIONS: Postoperative increases in intraocular pressure have been reported with sodium hyaluronate products. The IOP should be carefully monitored and appropriate therapy instituted if significant increases should occur. It is recommended that PROVISC® OVD be removed by irrigation and/or aspiration at the close of surgery. Do not overfill anterior chamber. Although sodium hyaluronate is a highly purified biological polymer, the physician should be aware of the potential allergic risks inherent in the use of any biological material; care should be used in patients with hypersensitivity to any components in this material. Cannula assembly instructions should be followed to prevent patient injury. ADVERSE REACTIONS: Postoperative inflammatory reactions such as hypopyon and iritis have been reported with the use of ophthalmic viscoelastics, as well as incidents of corneal edema, corneal decompensation, and a transient rise in intraocular pressure. ATTENTION: Reference the Physician Labeling/Directions for Use for a complete listing of indications, warnings and precautions. continued on page 54 © 2013 Novartis 9/13 VIS13035JAD-PI