RETROSPECTIVE STUDY OF INFECTIOUS KERATITIS IN ARGENTINA: Comparing a large ophthamic centre and a specialized center in ocular infection

Abstract

Abstract: : Purpose: to study incidence, risk factors and microbial isolates in infectious keratitis (excluding herpetic keratitis), comparing an ophthalmologic general clinic (GC) with a specialized center in ocular infection (SC) Methods: retrospective study of clinical records of patients with infectious keratitis in a) 514 patients of the GC between 1990 to 2002 and b) 253 patients evaluated in the SC between 1998 to 2002. Results: 507,356 clinical records were evaluated and the incidence of infectious keratitis in the GC was 1 per thousand (514 out of 507,356 clinical records evaluated). Contact lens was the risk factor more frequently founded (GC: 29%; SC: 39%).Samples for microbial analysis were taken from 62 out of 514 eyes (13%) in the GC (all of them without treatment) and, in sharp contrast, 100% of SC patients (140 with and 113 without treatment).Patients without treatment showed a positive culture in 45/62 eyes (73%) at the GC and in 98/113 eyes (87%) at the SC. In the last center, patients with previous treatment had positive culture in 80/140 eyes (57%). Microorganisms identified from cultures corresponded to bacteria (GC:95%; SC:71% ), fungus (GC:4%; SC:17% ), and acanthamoeba (GC:1%; SC:12% ) The bacteria spectrum was: gram positive (GC:80%; SC:58% ), gram negative (GC:18%; SC:40% ) and polimicrobial (2% in both centers). Conclusions: The fact that only 13% of eyes with infectious keratitis in the GC were cultured shows that general ophthalmologists prefer to use an empiric treatment. Samples were taken by ophthalmologists specialized in ocular infections in SC and this could explains the higher culture positive rate found in patients without previous treatment. Previous treatment significantly reduced the culture positive rate. Microorganisms recovered in SC showed a higher incidence of gram negative, fungus and acanthamoeba, compared to GC, probably because SC is a reference center that receives complicated cases.

Keywords: bacterial disease • clinical (human) or epidemiologic studies: prevalence/incidence • cornea: clinical science