Aims: To investigate the way in which ophthalmologists observe fundi and make diagnoses from their observations.
Methods: A set of 12 test photographs were presented to 9 ophthalmologists. The subjects were asked to identify the features in the photographs which are important for forming a diagnosis and were also asked to form differential diagnoses. The scanpaths of the subjects were recorded during their inspection of the photographs. Subsequently they were asked to trace over the important features of 4 of the photographs.
Results: The correctness of the diagnoses was described by weighted numerical scores. Differential diagnoses made after 30 seconds of inspection were significantly better than those made after 5 seconds. Irrespective of correctness, the reported diagnoses were dominated by the most obvious features of the photograph. Incorrect diagnoses were made either because the subjects failed to identify the significant features of the photograph or because they failed to comprehend the significance of the identified features.
Conclusion: Accurate fundoscopy involves both perception of diagnostic features and cognitive interpretation of these features. Verbal reports, eye movement recordings and tracings have been shown to reveal the features and interpretations used to make a diagnosis. These techniques will be used in a subsequent study to evaluate the relative contributions of formal training and experience to the development of diagnostic skills.
- differential diagnosis
- fundus photographs