What predicts bad outcomes in bacterial keratitis?
In 283 UK eyes with suspected bacterial keratitis, almost all had a risk factor (OSD 47%, contact lenses 35%, immunosuppression 18%); age >50, infiltrate >3 mm, and poor presenting vision predicted worse vision and slow healing.
Source
Risk Factors, Clinical Outcomes, and Prognostic Factors of Bacterial Keratitis: The Nottingham Infectious Keratitis Study
Study at a glance
- Design
- Cohort — Retrospective consecutive suspected bacterial keratitis presenting to Queen’s Medical Centre, Nottingham, 2015–2019 (Nottingham Infectious Keratitis Study).
- N
- N=283 · 283 patients / 283 eyes; mean age 54.4±21.0; 50.9% male; 45.2% culture-positive.
- Population
- Patients with suspected bacterial keratitis at a UK tertiary eye centre.
- Outcome
- Risk factors, culture results, hospitalisation/surgery, visual outcome (CDVA <0.6 logMAR), and delayed healing (>30 days).
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Retrospective chart review of Queen’s Medical Centre BK suspects 2015–2019, comparing culture-positive vs negative presentations and modeling poor final CDVA (<0.6 logMAR) and delayed epithelial healing.
What they found
128/283 (45.2%) culture-positive. Contact-lens cases linked to P. aeruginosa; non-CL cases to staphylococci (p=0.017). 57.2% hospitalized (mean 8.0 days); 16.3% needed surgery. Perforation 8.8%, NPL vision 3.9%, evisceration/enucleation 1.4%. Culture-positive eyes were older and more severe at presentation.
The limits
What it doesn't show
Single-centre retrospective data cannot prove causality of risk factors or that earlier treatment would have changed every poor outcome; 55% culture-negative so organism effects are incomplete.
Key terms
- Bacterial keratitis (BK)
- Corneal infection by bacteria; leading infectious keratitis type in the UK.
- Ocular surface disease
- Most common risk factor here (47.3%), including dry eye and related disease.
- CDVA
- Corrected-distance visual acuity; poor outcome defined as final CDVA <0.6 logMAR.
- Culture-positive BK
- 45.2% of eyes grew bacteria; associated with more severe presenting signs.
- P. aeruginosa
- Typical isolate in contact-lens-related BK in this series.
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Eyes included:
Common questions
How many eyes?
283 patients, one eye each.
Culture-positive rate?
45.2% (128/283).
Top three risk factors?
Ocular surface disease, contact lens wear, systemic immunosuppression.
Who had worse final vision?
Age >50, infiltrate >3 mm, and worse presenting acuity.
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