Posters

Characteristics of microbial keratitis as seen in a tertiary referral centre

Poster Details

First Author: G.Moussa UK

Co Author(s):    M. Rana   A. Lau   N. Dhillon   S. Rauz   A. Aralikatti   L. Low

Abstract Details

Purpose:

This is a retrospective analysis that aims to determine epidemiological data for this regional centre. We also wished to identify common organisms with the different predisposition to type of bacteria and the common antibiotic therapies used before and after sensitivities are acquired.

Setting:

Birmingham and Midland Eye centre, Sandwell and West Birmingham Hospital NHS Trust, Birmingham, United Kingdom

Methods:

Data was collected retrospectively for a period of twelve months (Jan 2013 to December 2013). Data was collected for 66 patients on a validated proforma for all admissions of microbial keratitis. Ocular risk factors (ORF) were identified as those with ocular surface disease, trauma, dry eyes, atopy, diabetes mellitus, topical immunosuppression and lid disorder. Bacteria were categorised into gram negative (GN) and positive (GP) based on corneal scrape culture results. Several groups were compared, CL lens wearers, topical therapy use on admission and those with ORF to their predisposition to type of bacteria. By looking through notes, initial antibiotic prescriptions were noted and subsequent antibiotic therapy after culture sensitivities were found.

Results:

Demographic data consisted of 57.6% being female versus 42.4% male. Left eye: 44.0%, Right Eye: 54.5%, Bilateral: 1.5%. Contact lenses (CL) were used in 28.8% of admissions. 51.5% had ORF. The most common bacteriological flora consisted of Staphylococcus (15.9%), Streptococcus (14.2%), Pseudomonas (12.7%) and Moraxella (11.1%). In total, 54.1% of bacteria identified were GP (45.9% GN). In CL users, 70% were GN (30% GP) and in non-CL wearers, 63% were GP (37% GN). The antibiotic with the highest sensitivity was Gentamicin in 27.3% of patients. Ciprofloxacin was sensitive in 19.7% of patients. The most commonly prescribed antibiotic therapies on admission were: G.Ofloxacin 56.1%, G.Penicillin 34.8% and G.Cefuroxime 28.8% and G.Gentamicin in 9.1% of patients. Most common antibiotic therapies in subsequent prescription after culture sensitivities were: G.Gentamicin 36.4%, G.Cefuroxime 27.3%, G.Cefuroxime 27.3%, G.Ofloxacin 24.2%, G.Penicillin 21.2%. 27.3% of patients were started on gentamicin after sensitivities were found. 34.8% of patients stopped ofloxacin after sensitivities. In patients with a corneal scrape positive for GP bacteria, the most used antibiotic therapies were: G.Ofloxacin 60%, G.Chloramphenicol 45%, G.Cefuroxime 40% and G.Penicillin in 30% of patients. In identified GN bacteria, G.Gentamicin 66.7%, G.Ofloxacin 46.7%, G.Ciprofloxacin and G.Penicillin in 26.7% of patients.

Conclusions:

This data demonstrates the most common bacterial infections in a tertiary referral centre over one year. CL wearers had a predisposition to gram-negative bacteria. Patients with ORF had a significant predisposition to gram-positive bacteria as echoed by patients using topical therapy regularly. A large proportion of patients were started on gentamicin after sensitivities were identified, and this was also the antibiotic with the highest sensitivity. This data suggests a review of antibiotic protocol may be warranted. As the one year study provided useful data, a three year retrospective analysis will be completed. FINANCIAL INTEREST: NONE