Profile of sight-threatening infectious keratitis: a prospective study

. Purpose: To prospectively study patients presenting with sight-threatening corneal ulcers with a view to identify the predisposing factors, causative organisms, clinical signs and treatment outcomes. Methods: Prospectively, over 3-year period, all cases with serious infective keratitis presenting to Queens Medical Hospital in Nottingham, UK, were recruited. Detailed information on the aetiology, culture results, signs & symptoms, the treatment given and the patient's response was collected and statistically analysed. Results: One hundred and forty-three eyes of 129 patients were enrolled. Thirty-one patients were managed as out-patients, and 98 were treated as in-patients. The mean duration of admission was 913days but was significantly higher in older patients and in Acanthamoeba keratitis cases. The important risk factors were ocular surface disease (32%), contact lens wear (26%) and previous ocular surgery (20%). Old age, deep infiltration, steroid use and poor initial vision were risk factors for prolonged course of treatment in bacterial keratitis. Corneal scrapings were done in 89% of the cases, but positive results were obtained only in 41.7%. Staphylococcus aureus was the most common isolated bacteria (18.8%). Acanthamoeba and Pseudomonas aeruginosa were the second and third common causative organisms (16.6% and 15%, respectively). Overall, 8.3% needed corneal grafting, which survived in 83.3% and eradicated infection in 100%. Conclusion: Microbial keratitis is an important cause of ocular morbidity. Previous ocular disease is an important predisposing factor. Old age, steroid use and poor presenting visual acuity are important prognostic indicators. Corneal grafting is an effective option for managing recalcitrant corneal infections.