Topical issues in the treatment of bacterial keratitis

Bacterial keratitis is an important cause of visual morbidity worldwide,(1) Contact lens wear remains the most common risk factor for bacterial kerati tis in most developed countries.' Interestingly, another form of refractive correction, in the form of incisional and laser surgery, has emerged as a cause of bacterial keratitis. Incisional refractive surgery has been report ed to have a complication rate for incidence of bacterial keratitis of 0.25 to 0.70%, with reoperation or enhancement after the primary procedure bein g a risk factor for infection.(3) Because of the large epithelial defect th at follows surface excimer laser treatment, one would expect a higher incid ence of infection as compared with incisional techniques. However, few data are available on the incidence of infectious keratitis after photorefracti ve keratectomy (PRK). Amayen and associates(4) reported 2 cases of bacteria l keratitis after PRK. The authors did not report the patient population si ze that included these patients and an estimate of the incidence of bacteri al keratitis. Al-Rajhi and associates(5) reported three cases of bacterial keratitis in a series of 258 patients undergoing phototherapeutic keratecto my. This yielded an incidence of 1.2%. Automated lamellar keratoplasty and laser in situ keratomileusis (LASIK) have been associated with postoperativ e bacterial keratitis.(6,7) One of these cases was an unfortunate patient w ith bilateral bacterial keratitis after bilateral simultaneous LASIK.(7) Although this is a rare complication, it is an additional reason why we rec ommend against bilateral simultaneous LASIK. Although the clinical impact o f bacterial keratitis is not controversial, a number of aspects regarding t he diagnosis and treatment of bacterial keratitis have become fairly contro versial in the last few years, igniting some furious debates. The purpose o f this chapter is to review the recent literature and to discuss two contro versial areas regarding bacterial keratitis: the use of cultures in the dia gnosis and determination of treatment of corneal ulcers, and the use of flu oroquinolones in the treatment of bacterial keratitis.