Abstract
Purpose :
Having an accurate overview of the spectrum of pathogens involved in infectious keratitis in a given geographic region is important when deciding on empiric therapy. In this study, we evaluate the spectrum of organisms cultured from corneal samples over a 4-year period.
Methods :
This was a retrospective review of corneal scrapes taken between July 2013 and July 2017 at the Tennent Institute of Ophthalmology Gartnavel General hospital Glasgow, Scotland.
Results :
A total of 521 corneal scrapes were taken over this 4-year period, with a total of 198 positive cultures (38%).
Out of the 198 positive cultures, 90 were male and 108 females with an average age of 58.5 years (age range 36-81).
43% (86) of the positive cultures grew gram-positive organisms. Out of these, Staphylococcus aureus was the most common (38%).
43% grew gram-negative organisms and unlike other studies, Moraxella (46%) was the most common gram-negative organism cultured. The data shows an increasing trend of Moraxella positivity over the 4-year period with only 3 positive cultures in 2014 compared to 15 in 2016.
12 (6%) scrapes grew fungi and 13 (6.5%) showed a mixed growth of both gram-positive and gram-negative organisms.
37 eyes out of the 198 positive cultures were contact lens users. Pseudomonas was the most common organism isolated in these contact lens users at 43% followed by fungi (13%).
Conclusions :
This series shows an equal trend between gram-positive and gram-negative bacteria as the etiology of infectious keratitis within this region. Staphylococcus aureus is the most commonly isolated gram-positive organism and Moraxella the most commonly isolated gram-negative organism.
As per other studies, pseudomonas is the most commonly isolated organism in contact lens users.
There seems to be an increasing trend in prevalence of Moraxella over the 4-year period, which would be an important factor to consider in empirical antibiotic treatment regimes within this geographical area.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.