Various sources report a recent increase in the incidence of infectious endophthalmitis following clear corneal cataract surgery.1-3 These reports have renewed interest and investigation into more effective methods of preventing postoperative endophthalmitis. Our preference is intracameral gatifloxacin.
THE CASE FOR INTRACAMERAL ANTIBIOTICS
In addition to cefuroxime, vancomycin has been studied for intracameral use. Because bacteria continually develop resistance to antibiotics, we believe that ongoing research is needed to identify the most effective antibiotics to stay ahead of this evolutionary process. The selected antibiotics should be (1) safe for intraocular administration, (2) broad spectrum, and (3) bacteriocidal, dose-dependent killing agents with fast kill curves.
WHY FOURTH-GENERATION FLUOROQUINOLONES ARE SUPERIOR
We recently conducted two studies in order to determine if gatifloxacin could safely be used for intracameral prophylaxis.
SAFETY OF INTRACAMERAL GATIFLOXACIN
Along with Eric Donnenfeld, MD, and colleagues, we conducted a small study of the safety of intracameral gatifloxacin in 40 human subjects undergoing unilateral cataract extraction. We found no evidence of intraocular toxicity with a 100 µg/0.1 mL dose.11 We evaluated patients' BCVA, IOP, corneal clarity, dilated fundus examination, and ultrasonic pachymetry at 1 day, 1 week, 1 month, and 3 months postoperatively. Patients' mean preoperative BCVAs improved from 20/74 to 20/24 postoperatively at 1 week and to 20/22 at both 1 and 3 months. Seven of 40 patients had as high as grade 2 corneal edema on the first postoperative day, but all patients had clear corneas on subsequent examinations. A mean increase in IOP of 6 mm Hg on the first postoperative day (P<.001) had normalized on subsequent examinations. We found no significant changes in ultrasonic pachymetry or retinal pathology in any patients, and none developed endophthalmitis. Intracameral gatifloxacin therefore appears to be safe and well tolerated at a concentration of 100 µg/0.1 mL at the conclusion of cataract surgery.
Since we conducted these preliminary studies, intravenous gatifloxacin (Tequin; Bristol-Myers Squibb Company, Princeton, NJ) is no longer marketed in the US. If an unpreserved gatifloxacin becomes available in the future, these studies could be the basis of further research.
Currently, of course, the prophylactic use of intracameral fluoroquinolones in cataract surgery is considered off label and, as such, should be driven by the judgment of the individual physician and by evidence-based literature.
Brian C. K. Au, MD, is a second-year ophthalmology resident from the University of Texas Medical Branch in Galveston. He acknowledged no financial interest in the products or companies mentioned herein. Dr. Au may be reached at (409) 939-6543; firstname.lastname@example.org.