Altered Patterns of Fungal Keratitis at a London Ophthalmic Referral Hospital: An Eight-Year Retrospective Observational Study

Abstract

PurposeIn previous studies of fungal keratitis (FK) from temperate countries, yeasts were the predominant isolates, with ocular surface disease (OSD) being the leading risk factor. Since the 2005–2006 outbreak of contact lens (CL)-associated Fusarium keratitis, there may have been a rise in CL-associated filamentary FK in the United Kingdom. This retrospective case series investigated the patterns of FK from 2007 to 2014. We compared these to 1994–2006 data from the same hospital.DesignRetrospective observational study.MethodsAll cases of FK presenting to Moorfields Eye Hospital between 2007 and 2014 were identified. The definition of FK was either a fungal organism isolated by culture or fungal structures identified by light microscopy (LM) of scrape material, histopathology, or in vivo corneal confocal microscopy (IVCM). Main outcome measure was cases of FK per year.ResultsA total of 112 patients had confirmed FK. Median age was 47.2 years. Between 2007 and 2014, there was an increase in annual numbers of FK (Poisson regression, P = .0001). FK was confirmed using various modalities: 79 (70.5%) by positive culture, 16 (14.3%) by LM, and 61 (54.5%) by IVCM. Seventy-eight patients (69.6%) were diagnosed with filamentary fungus alone, 28 (25%) with yeast alone, and 6 (5.4%) with mixed filamentary and yeast infections. This represents an increase in the proportion of filamentary fungal infections from the pre-2007 data. Filamentary fungal and yeast infections were associated with CL use and OSD, respectively.ConclusionsThe number of FK cases has increased. This increase is due to CL-associated filamentary FK. Clinicians should be aware of these changes, which warrant epidemiologic investigations to identify modifiable risk factors.

Fungal keratitis in the Republic of Ireland

“…In their study 69.6% of cases were caused by filamentary fungi and the most common risk factor was contact lens wear, which was present in 57.1%. 20 Our study would support that trend. In our study 66.7% of cases identified filamentary organism and while pre-existing ocular surface disease was the most common risk factor in our study (18 cases (42.9%)), contact lens wear was almost as common (17 cases (40.5%)).…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Many large case series from a variety of tropical countries have been reported, in contrast to a small number of singleinstitution case series from temperate areas of the world including the United States, [14][15][16][17] Australia, 18 and the United Kingdom. 19,20 In temperate climates, it appears to be a rare disease with only 1-5% of cases of microbial keratitis due to fungi. 14,18,19 Though less common, it remains a severe disease requiring therapeutic keratoplasty in 12-48% of cases and enucleation in up to 6% of cases.…”

“…In that study 70% of cases of fungal keratitis were due to filamentary infections, with Fusarium species the most common species. 20 Only one population-based study of the prevalence, risk factors, causative organisms, and clinical outcomes of fungal keratitis in temperate regions has been reported to-date. 22 The aim of this study is to report the epidemiological, clinical, and microbiological features of all confirmed fungal keratitis cases in the Republic of Ireland, a temperate country, in a 6-year population-based study.…”

Common eye infections

“…Specific antifungal or anti-acanthamoebal therapy is needed and treatment may take some months. [13][14][15] The signs and symptoms of bacterial keratitis are shown in the Table and Fig. 4.…”

The diagnosis and management of contact lens‐related microbial keratitis

“…It was first highlighted that Acanthamoeba did not return to the base level before the outbreak in the mid‐2000s and indeed an increase in more recent years, beginning around 2012, has been reported from several centres not linked to a specific disinfecting solution . More recently, an increased level of filamentary fungal CL MK cases has been reported …”