Optometrists Correctly Identify nAMD Needing Re-treatment

Laurie Barclay, MD

August 04, 2016

Optometrists' ability to classify retinal lesions for re-treatment decisions regarding quiescent neovascular age-related macular degeneration (nAMD) is not inferior to that of ophthalmologists, according to a virtual noninferiority trial published July 8 in BMJ Open. The findings suggest optometrists could potentially help reduce ophthalmologists' workload caring for patients with quiescent nAMD.

Because dormant nAMD lesions can reactivate, patients need regular monitoring, including visual acuity checks, clinical examination, and optical coherence tomograms to determine whether treatment should be restarted.

"Regular monthly review in the UK Hospital Eye Service (HES) blocks clinic space, uses valuable resources, is expensive and is also burdensome to the patients and their carers," write Barnaby C. Reeves, DPhil, from the Clinical Trials and Evaluation Unit, School of Clinical Sciences, University of Bristol, United Kingdom, and colleagues. "This situation has prompted service providers to explore innovative models of service provision."

The Effectiveness of Community versus HES (ECHoES) trial found that optometrists were similar to ophthalmologists in overall proportion of correctly classified lesions but were more cautious, less likely to have false-negative errors, and more likely to have false-positive errors.

The researchers note that more cautious decision-making by optometrists reduces the risk that they would classify a reactivated lesion as quiescent or suspicious and reflects their service contract requiring them to refer any suspected pathology. However, their caution reduces the potential that community monitoring could lower hospital-based ophthalmologists' workload and be cost-effective.

Similar studies have shown acceptable levels of agreement between optometrists' and ophthalmologists' decisions regarding glaucoma and accident and emergency services.

ECHoES Study Design and Findings

ECHoES was a randomized, virtual noninferiority trial comparing HES ophthalmologists vs community optometrists in their ability to correctly classify nAMD retinal lesions at follow-up for quiescent disease. The ophthalmologists had experience in the AMD service, whereas the optometrists, although fully qualified, had no experience in nAMD shared care.

Using an Internet-based application, both groups received webinars and training and completed a screening test for classification accuracy. Those who failed the screen completed another set of training vignettes. All who passed reviewed vignettes created from patient data, including clinical summaries, color fundus photographs, and optical coherence tomographic images.

Researchers compared both groups' classifications of retinal lesions against experts' classifications. Of 155 registered participants, 96 (48 in each group) completed the study and had analyzable data.

Optometrists correctly classified lesion activity status, which was the primary outcome, in 1702 of 2016 (84.4%) vignettes; ophthalmologists did so in 1722 of 2016 (85.4%) vignettes (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.66 - 1.25; P = .54). The difference fell within the prespecified limit of 10% absolute difference and thus showed that optometrists were noninferior to ophthalmologists in identifying lesion status.

In addition, the two groups made potentially sight-threatening errors at similar rates (optometrists: 57 of 994 [5.7%]; ophthalmologists: 62 of 994 [6.2%]; OR, 0.93; 95% CI, 0.55-1.57; P = .789). Compared with optometrists, ophthalmologists evaluated lesion components as being present less often, and they expressed greater confidence in their decisions.

Optometrists May Help Reduce Hospital Workload

"Shared care with optometrists monitoring quiescent nAMD lesions has the potential to reduce workload in hospitals," the study authors write.

"Optometrists would have liked more training but nevertheless achieved non-inferior performance with respect to the prespecified inferiority margin."

Countering the objection that virtual decision-making differs from in-person clinical decision-making, the researchers note that it has similarities to how some hospitals manage their nAMD monitoring workload. Other potential study limitations include use of spectral domain systems to create vignette images that had poorer-quality visualization than those in current use.

Compared with ophthalmologists, more optometrists had to complete two sets of training vignettes to pass the screening test. Nonetheless, the main study findings suggest that webinars combined with training vignettes allowed optometrists to classify lesion activity as well as the ophthalmologists.

The researchers suggest that the Internet platform used in this study is suitable for delivering more training, refresher courses, and interaction with experts about difficult images. However, they caution that implementing shared care would necessitate use of a rigorous standard, as was used in this study, to ensure that optometrists had been properly trained in lesion classification.

"The barriers to implementing a shared care policy based on the model evaluated in ECHoES...could be addressed by implementing continuous quality assurance of the performance of optometrists and rapid referral to HES alongside shared care," the study authors conclude.

The National Institute for Health Research Health Technology Assessment Programme funded this study. Five coauthors reported various financial disclosures, involving National Institute for Health Research, Alimera Sciences, Bayer, Roche, Novartis, and/or Allergan. The other authors have disclosed no relevant financial relationships.

BMJ Open. 2016;6:e010685. Full text

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