Has the use of optical coherence tomography in community optometrists’ referrals improved diagnostic accuracy for glaucoma?

Abstract

AbstractPurposeIn recent years, community optometry practices have begun to use optical coherence tomography (OCT) as part of glaucoma assessment, the result of which is increasingly cited as a reason for referral into hospital glaucoma clinics. We aim to assess whether the addition of OCT scanning has improved diagnostic accuracy of glaucoma referrals from community optometry practices.MethodsA prospective observational study was conducted, which includes all glaucoma referrals from community optometrists to the Portsmouth Glaucoma Referral Refinement (GRR) scheme from July 2019 until February 2020. Patient demographics, tests performed, reasons for referral, and the final diagnosis from glaucoma clinic were collated. A positive diagnosis includes open angle glaucoma, ocular hypertension, glaucoma suspect and narrow angle glaucoma.ResultsA total of 248 eligible referrals were analysed. Overall, the positive predictive rate was 20% (n = 50), which is similar to previous audits of glaucoma referrals in Portsmouth (1). 25 subjects had an OCT scan as part of their referral, and the OCT given as a reason for referral in 24 of these cases. 25% (n = 6) resulted in a positive diagnosis; however, all these patients had at least 2 other abnormal tests at initial assessment (from IOP, disc appearance, and visual field testing) which were also reasons for referral, suggesting they would have been referred regardless of the OCT. In six cases, the only reason for referral was OCT findings, none resulted in a positive diagnosis after clinic review. The highest PPV (75%, n = 6) was achieved when all three of IOP, disc, and visual field were given as reasons for referral.ConclusionsThe use of OCT in glaucoma assessment at community optometry practices is still not very widespread. This early evidence suggests OCT performed by community optometrists does not improve diagnostic accuracy of referrals into hospital eye services.Reference1. Lockwood, A., Kirwan, J. and Ashleigh, Z., 2010. Optometrists referrals for glaucoma assessment: a prospective survey of clinical data and outcomes. Eye, 24(9), pp. 1515–1519.