Abstract
Purpose: :
To describe the referral pathways, treatment and outcome of contact lens (CL) related microbial keratitis (MK) in Australia and New Zealand.
Methods: :
Cases in 15–64 year olds were identified via surveillance studies of Australia and New Zealand in 2003–2004 and were stratified into severe (central 4mm, >2mm or hypopyon/culture proven/vision loss, 123/297) and non–severe (174/297). Referral pathways, mode of treatment and 12–month rate of reduction of best–corrected visual acuity were characterised. Rate of resolution of symptoms within 1 week were compared for culture result (Gram–negative, acanthamoeba, fungal or nocardia keratitis [CP] vs remainder [Neg]) and effect of treatment delays (TD/nTD).
Results: :
19% presented to emergency departments, 33% general medical practitioner (GP), 45% optometrist and 2% other. There was a delay of >12 hrs before commencing appropriate therapy in 33% and this was associated with initial treatment by a GP (34/56 vs 10/117, p<0.001). Hospital clinics managed 67% of cases (175/260). Private clinics (33%, 85/260) predominantly used fluoroquinolone monotherapy (FQ) 80/105 (76%), whereas 70/174 (40%) of cases managed in hospital clinics were treated with fortified duotherapy (FD) and 96/174 (55%) FQ. Hospital clinics managed a higher proportion of severe disease (89/175 51% vs 16/85 19%, p<0.001) and 82/174 of cases (47%) were treated as in–patients. In hospitals, FD was more likely to be used in severe disease (54/87, 62% vs 16/83, 19%, p<0.001). For 160/268 (60%) of cases, symptoms had resolved in <7 days, which was influenced by both causative organism and treatment delays: CP/TD 13% vs CP/nTD 44% vs Neg/TD 55% vs Neg/nTD 72% (p<0.001). Vision loss was 14.2% annually in Australia (35/245).
Conclusions: :
CL related MK is successfully managed with topical anti–microbial therapy in the majority of cases and only a small number result in reduced vision. Fluoroquinolone therapy is widespread especially in private clinics but more severe disease still tends to be treated with fortified duotherapy in hospital clinics. Timely diagnosis and commencement of appropriate therapy is important in reducing the disease duration.
Keywords: contact lens • keratitis • clinical (human) or epidemiologic studies: health care delivery/economics/manpower