Clinical characteristics and visual outcome in patients with Pseudomonas keratitis

Abstract

Aim: To study the clinical and microbiological features and visual outcomes of patients with Pseudomonas keratitis. Methods: The clinical records of 37 patients affected by microbial keratitis with positive corneal scrapes for Pseudomonas sp., who were diagnosed and treated at Moorfields Eye Hospital, London, UK over a 12-month period were retrospectively reviewed. Predisposing factors, microbial culture results, clinical course and visual outcomes were analysed. Results: Contact lens wear (25 cases [67.5%]) and surface ocular diseases (6 cases [16.2%]) were the main predisposing factors. No ocular trauma aetiology was present in this series. All contact lens-related keratitis were observed in soft contact lens users (19 cases [51.3%] monthly disposable lenses, and 6 cases [16.2%] daily disposable lenses). A total of 14 cases (37.9 %) of the Pseudomonas sp. isolates were early suspected in the direct gram examination. There was only one case resistant to ofloxacin. Four (10.8 %) of the 37 eyes required surgical intervention, 90% of the patients had some degree of anterior chamber activity at presentation, 30% had an hypopion level. There was a ‘good’ clinical outcome (best corrected visual acuity [BCVA] >6/12) in 32 patients (86.4 %), a residual corneal scar was seen in 72.9 % of the cohort. Conclusions: A ‘good’ visual outcome was described even when a very high rate of intraocular inflammation and severe corneal compromise had occurred; this is due to a highly specialised management of the cases with a prompt use of corticosteroids that helped to manage the massive inflammatory reaction often associated to Pseudomonas sp. However, the presence of residual corneal scarring explains the loss of BCVA lines in 60% of the cases and limited final visual outcome.