Clinical Study
Eye (2009) 23, 153–160; doi:10.1038/sj.eye.6702953; published online 17 August 2007
Characteristics of and risk factors for contact lens-related microbial keratitis in a tertiary referral hospital
Proprietary interests: The authors have no conflicting relationships or commercial connection to the topic of this paper.
K Edwards1,2, L Keay1,2, T Naduvilath2, G Snibson3,4, H Taylor2,3,4 and F Stapleton1,2
- 1School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
- 2Vision Cooperative Research Centre, Sydney, Australia
- 3Centre for Eye Research Australia, The University of Melbourne, Melbourne, Australia
- 4Corneal Unit, Royal Victoria Eye and Ear Hospital, Melbourne, Australia
Correspondence: F Stapleton, School of Optometry and Vision Science, Level 3, North Wing, Rupert Myers Building, Gate 14, Barker Street, UNSW SYDNEY NSW 2052, Australia. E-mail: f.stapleton@unsw.edu.au
Received 9 February 2007; Revised 17 July 2007; Accepted 17 July 2007; Published online 17 August 2007.
Abstract
Aim
A retrospective case–control study was conducted at a tertiary referral hospital to determine the characteristics of and risk factors for contact lens (CL) related presumed microbial keratitis.
Methods
Two hundred and ninety-one cases of presumed microbial keratitis were retrospectively identified over a 2-year period. Records were reviewed for a history of CL wear and, where identified, CL, demographic, and clinical data were collected. Lens wearing controls (n=186) were identified by a community telephone survey. Multiple logistic regression estimated risk factors for infection and vision loss.
Results
Ninety-nine (34%) new cases of presumed microbial keratitis were associated with CL wear. Overnight soft CL use was associated with an increased risk of infection compared to daily disposable CL wear (odds ratio (OR): 8.03, 95% confidence interval (CI): 1.82–35.46). Compared with older CL wearers, 15–24 year olds had a 3.5 times greater risk of infection (OR, 95% CI: 1.7–7.4). Of the 84 cases with available data, 24 (29%) lost two or more lines of best-corrected visual acuity. Delaying treatment by 49–72 h had a 4.5 times (OR, 95% CI: 1.4–14.9) greater risk of visual loss compared to seeking treatment early. Of the 99 cases of infection, 88 were scraped and 78% (69/88) of these returned a positive culture. Gram-positive bacteria were the predominant causative organisms.
Conclusion
Overnight use of CL and youth carry a greater risk of infection. Practitioners should reinforce the importance of proper CL care at all times, and early presentation following the onset of symptoms.
Keywords:
keratitis, contact lenses, case–control studies
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated

