Elsevier

Ophthalmology

Volume 117, Issue 4, April 2010, Pages 717-723
Ophthalmology

Original article
Clinical Assessment of Stereoscopic Optic Disc Photographs for Glaucoma: The European Optic Disc Assessment Trial

Presented in part at: the Association for Research in Vision and Ophthalmology meeting, May 2007, Fort Lauderdale, Florida.
https://doi.org/10.1016/j.ophtha.2009.09.026Get rights and content

Purpose

To determine the diagnostic accuracy of judging optic disc photographs for glaucoma by ophthalmologists.

Design

Evaluation of diagnostic test and technology.

Participants

A total of 243 of 875 invited ophthalmologists in 11 European countries.

Methods

We determined how well each participant classified 40 healthy eyes and 48 glaucomatous eyes with varying severity of the disease on stereoscopic slides. Duplicate slides were provided for determining intraobserver agreement. All eyes were also imaged with the GDx with variable corneal compensation (GDx-VCC) (Carl Zeiss Meditec AG, Jena, Germany) and the Heidelberg Retina Tomograph (HRT) I (Heidelberg Engineering GmbH, Heidelberg, Germany). Diagnostic accuracies of clinicians were compared with those of the best machine classifiers.

Main Outcome Measures

Accuracy of classification, expressed as sensitivity, specificity, and overall accuracy. Intraobserver agreement (κ).

Results

The overall diagnostic accuracy of ophthalmologists was 80.5% (standard deviation [SD], 6.8; range, 61.4%–94.3%). The machine classifiers outperformed most observers in diagnostic accuracy; the GDx-VCC nerve fiber indicator and the HRT's best classifier correctly classified 93.2% and 89.8% of eyes, respectively. The intraobserver agreement (κ) varied between −0.13 and 1.0 and was on average good (0.7).

Conclusions

In general, ophthalmologists classify optic disc photographs moderately well for detecting glaucoma. There is, however, large variability in diagnostic accuracy among and agreement within clinicians. Common imaging devices outperform most clinicians in classifying optic discs.

Financial Disclosure(s)

Proprietary or commercial disclosure may be found after the references.

Section snippets

Ophthalmologists

We invited ophthalmologists in 11 countries across Europe (the 5 bigger countries [France, Germany, Italy, Spain, and United Kingdom] and 6 smaller countries [Austria, Belgium, Finland, Greece, Hungary, and The Netherlands]) to participate in this study. They all received letters in their native tongue, explaining the aim of the study, the estimated time their participation would take, and the anonymous nature of the study. They were also promised to receive a small gift on completion. Those

Results

Of the 875 ophthalmologists who were invited, 276 (31.5%) agreed to participate. Of these, 245 (88.8%) returned a fully completed score sheet. Figure 2 shows the number of those invited per country and the number of completed score sheets that were returned. The rate of complete responders varied considerably between countries. The highest rate was in Austria (69.2%). France and Italy showed the lowest rate of approximately 15%. Two of the participants had not yet completed their residency;

Discussion

We have found that ophthalmologists across Europe correctly classify stereoscopic optic disc photographs in approximately 80% of cases. The range, however, was large with some correctly classifying approximately 60% of cases. The conditions for judging optic discs in our study were almost ideal; one could take as much time as desired, without real-life interferences such as eye movements, blinks, photophobia, and variable patient cooperation. In addition, we used only healthy and glaucomatous

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  • Cited by (113)

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    Manuscript no. 2009-64.

    Financial Disclosure(s): The author(s) have made the following disclosure(s):

    NJ Reus, Pfizer, CLS; HG Lemij, Pfizer, CLS; DF Garway-Heath, Pfizer, CLS; Heidelberg Engineering, S; Carl Zeiss Meditec, CS; PJ Airaksinen, none; A Anton, Pfizer, L; Carl Zeiss Meditec, C; AM Bron, Pfizer, C; C Faschinger, Pfizer, CL; G Holló, Pfizer, CL, Carl Zeiss Meditec, C; M Iester, none; JB Jonas, Pfizer, C, Carl Zeiss Meditec, L, Heidelberg Engineering, L; A Mistlberger, none; F Topouzis, Pfizer, CL; TG Zeyen, Pfizer, L.

    Pfizer Inc., provided unrestricted financial support. They had no role in the design or conduct of this research; the data collection, analysis, and interpretation; the preparation of the manuscript; or the decision to submit the manuscript for publication.

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