Abstract
Purpose :
Fungal keratitis (FK) is an important cause of microbial keratitis. In previous studies from temperate countries, such as the United Kingdom, yeasts were the predominant cause of FK; ocular surface disease (OSD), topical steroids and ocular surgery were the leading risk factors. In recent years, an increase in FK caused by filamentary fungi associated with contact lens wear has been suspected. This study investigated the clinical and microbiological patterns of FK from 2007 to 2014 and compared these to pre-2007 data from the same institution.
Methods :
A retrospective observational study of all cases of FK presenting to Moorfields Eye Hospital over an 8-year period. Definition of FK: (i) fungal organism isolated from culture of corneal tissue, or (ii) any fungal structures identified by light microscopy (LM) of scrape material, histopathology or in-vivo corneal confocal microscopy (IVCM).
Results :
115 patients had a diagnosis of FK. There was an overall increase in absolute annual numbers of FK, from a crude average of 4.5 to 14.4/year. Mean age was 47.2 ± 15.9 years; younger than pre-2007 data (57.0 years, p=0.0004). In 79 (68.7%) a fungal organism was isolated by culture. Fungi were identified by LM in 16 (13.9%), histopathology of corneal biopsies in 5 (4.3%) and IVCM in 61 (53%). Combining these diagnostic modalities, 84 (73%) were diagnosed with filamentary fungus and 31 (27%) with yeast infection. There were 91 fungi isolated by culture: 30 (33%) were yeasts, and 61 (67%) were filamentary fungi. This demonstrates a marked increase in the proportion of filamentary fungal infections (pre-2007 data: 39.7%; p=0.001). OSD was present in 38 (33.0%), a significantly lower proportion than pre-2007 data (42.4%; p=0.001). Contact lens use was associated with 64 (55.7%), a significantly higher proportion compared to pre-2007 (15.2%; p<0.001). The proportion of FK associated with trauma has not changed (9.6%), with similar rates of yeasts and filamentary fungi (p=0.74). Yeasts were associated with OSD, ocular surgery, and use of topical steroids (p<0.001). Filamentary fungi were associated with contact lens wear (p<0.001).
Conclusions :
FK appears to be presenting more frequently in London. Most of this rise is driven by an increase in filamentary fungal infection associated with contact lens wear. Clinicians must be aware of these important changes in clinical and microbiological patterns.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.