Editorial

Who should manage contact lens related microbial keratitisin Australia and New Zealand?

In this month’s journal Keay, Edwards and Stapleton examine thereferral pathways and management of contact lens related microbialkeratitis in Australia and New Zealand.1

The article raises a number of important epidemiological, diag-nostic and treatment issues that touch on many of the controversiesin this important area of public health. The paper is based on dataacquired from a surveillance study conducted in Australia and NewZealand in 2003. There was a 96% rate of participation amongstophthalmologists, hospital clinics and optometrists. This is a reflec-tion of the importance in which this issue is viewed by ophthal-mologists and reflects positively on their willingness to participateand cooperate in important epidemiological studies.

The differentiation between infective and non-infective contactlens related keratitis is not always easy. In many studies only culturepositive cases are considered.2 This approach excludes a significantnumber of culture negative presumed infective keratitides.3 Keayet al. have accepted a diagnosis of microbial keratitis if there wasevidence of anterior chamber activity, progressive significant painor a part of the lesion was within the central 4 mm. Whilst this is areasonable approach, given that the study did not attempt toproduce incidence rates, it could have resulted in the inclusion ofnon-infective cases and it is likely that a percentage of the mildercases in fact do not represent a genuine infective keratitis. It wouldbe useful to look separately at the culture positive and moderate tosevere cases within their cohort.

Given that 97% of contact lenses are prescribed and dispensedby optometrists, it is not surprising that a significant percentage ofthese contact lens related microbial keratitis cases presented tooptometrists (41%). Interestingly, only 23% presented to emer-gency departments but perhaps more importantly, 34% presentedto general practitioners. In the total cohort, 67% ended up beingmanaged in hospitals. As one would expect, this included most ofthe moderate and severe cases.

The authors identified interesting interstate differences in inpa-tient versus outpatient management. The Royal Victorian Eye andEar Hospital treats patients almost exclusively on an outpatientbasis whereas in New South Wales and Western Australia, thehospital treated cases were more likely to be inpatients. This mayreflect a difference in the availability of treatment method fromstate to state but certainly would have an impact on the relativecosts of treating these cases.4 The other significant difference inmanagement related to the antibiotics used. The debate betweenthe relative efficacy of combined cephalosporin and aminoglyco-side versus a fluoroquiniolone continues.5 A case can clearly bemade for both treatment modalities with a fluoroquiniolone mono-therapy, more likely to be used in an outpatient or private clinicsetting and a combined aminoglycoside and cephalosporin moreeasy to deliver on an inpatient basis. A recent study by Ly et al.

(2006) of patients admitted to Sydney Eye Hospital reflects the factthat most microorganisms would be successfully treated under bothregimens.3 Green et al., however, have identified some increasingresistance to cephalothin.6

The authors conclude that the overall management of microbialkeratitis in Australia and New Zealand is successful despite thevariations in management. They do suggest, however, that there isroom for improvement. A number of patients (33%) experienced adelay of two or more days before appropriate therapy wascommenced. The authors point the finger fairly and squarely at thesubgroup who initially presented to general medical practitionerswho commenced treatment without referral to an ophthalmologist.A few cases were also highlighted in which inappropriate treat-ments were given.

It is important to apply caution when drawing such conclusionsfrom studies which by their design have factual gaps. It is possiblethat some of the patients when presenting to general practitionerswere only in their most early stages and that there was little in theway of clinical signs for the general practitioner to identify a casethat would proceed to a severe microbial keratitis. It is also obvi-ously very difficult for a general practitioner, without a slit-lamp, toidentify clinical corneal features that would help with earlydiagnosis. But early diagnosis is critical in contact lens relatedinfection. It is mandatory that all primary eye care practitionershave a high index of suspicion and a low threshold for tertiaryreferral.

It is inappropriate for a general practitioner to treat a patientwith a contact lens related infiltrate or suspicious contact lensrelated keratitis with topical steroids. In this study there are fourinstances in which the treatment delay group were given topicalsteroids at presentation. In each of these cases, severe diseaseresulted with three out of four requiring hospitalisation.

Patients with red eyes, whether it is contact lens related or not,continue to present to their general practitioner who remains afundamental and integral part of primary eye care in Australia andNew Zealand. Improvement in initial management and appropriateand timely referral can occur through education, with an encour-agement to use magnification with examination, communicateappropriately with an ophthalmology colleague and when in doubt,to refer.

This paper is relevant to the current debate on therapeuticaccess for optometrists: Should they be able to treat microbialkeratitis with a fluoroquinolone?

Whilst this controversial issue is outside the scope of this par-ticular editorial, relevant points can be gleaned from Keay’s study.1

The management of microbial keratitis can be extremely difficultand even amongst corneal specialists, the treatment options remaincontroversial. The identification of microorganisms, the choice of

Clinical and Experimental Ophthalmology 2008; 36: 204–205doi: 10.1111/j.1442-9071.2008.01732.x

© 2008 The AuthorJournal compilation © 2008 Royal Australian and New Zealand College of Ophthalmologists

medication, when it should be changed, when there is indeed evi-dence of clinical recovery and when steroids can be safely admin-istered, are difficult questions and if inappropriately handled canresult in significant visual morbidity. It is not possible to obtain thelevel of clinical experience required to make these decisionsthrough a didactic course or with minimal clinic exposure.

The importance of a well resourced corneal unit at a publichospital in the successful management of microbial keratitis can notbe underestimated. Keay’s study underlines this important issue.Not only were all of the moderate and severe cases treated in thehospital setting but the vast majority achieved resolution.

The final point I wish to highlight is hidden in a small section ofthis interesting paper. A salient feature of health care in Australiaand New Zealand are that the majority of microbial keratitis casesoccurred in regions which had high access ability to health care.Despite the limitations of our health care systems at least it isaccessible to all.

This study is highly relevant and thought provoking. It reflectson many positive aspects of eye care in Australia and New Zealand;a willingness by eye care professionals to co-operate in patient careand in epidemiological studies, a high success rate in managementof microbial keratitis and an almost universal accessibility to healthcare. The Corneal Clinics within our hospitals will remain theprimary resource for difficult and complex cases and must beresourced appropriately. Improvement can occur through furthereducation, communication and a willingness to cooperate amongsteyecare practitioners.

Gerard Sutton FRANZCODepartment of Ophthalmology, Auckland University, Sydney Eye Hospital &

The Eye Insititute, Chatswood, Australia

REFERENCES

1. Keay LEK, Stapleton F. Referral Pathways and management ofcontact lens related microbial keratitis in Australia and NewZealand. Clin Experiment Ophthalmol 2008; 209–16.

2. Green MD, Apel AJ, Nadurilath T, Stapleton FJ. Clinical out-comes of keratitis. Clin Experiment Ophthalmol 2007; 35: 421–6.

3. Ly CN, Pham JN, Badenoch PR et al. Bacteria commonly isolatedfrom keratitis specimens retain antibiotic susceptibility to fluo-roquinolones and gentamicin plus cephalothin. Clin ExperimentOphthalmol 2006; 34: 44–50.

4. Keay L, Edwards K, Brian G, Stapleton F. Surveillance of contactlens related microbial keratitis in Australia and New Zealand:multi-source case-capture and cost-effectiveness. Ophthalmic Epi-demiol 2007; 14: 343–50.

5. Daniell M, Mills R, Morlet N. Microbial keratitis: what’s thepreferred initial therapy? Br J Ophthalmol 2003; 87: 1167.

6. Green M, Apel A, Stapleton F. A longitudinal study of trends inkeratitis in Australia. Cornea 2008; 27: 33–9.

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© 2008 The AuthorJournal compilation © 2008 Royal Australian and New Zealand College of Ophthalmologists