Abstract
Abstract: :
Purpose: To determine if knowledge of intraocular pressure (IOP), visual field, and other clinical patient information influence clinical evaluation of optic disc for glaucoma. Methods: Sixteen raters independently evaluated 52 stereo disc photos. Three raters were glaucoma specialists, one was a glaucoma fellow, five were ophthalmology residents and seven were medical students. The specialists, fellow and residents recorded their impressions of whether the nerve was glaucomatous and all raters determined the cup/disc ratio. Several days later, the identical slides were shuffled and evaluated twice more. These two readings were accompanied by a set of ancillary patient data that contained information (either correct or incorrect) about the age, IOP and visual field. The observers evaluated the stereo disc photographs in the context of the clinical information that accompanied each pair of photographs. This clinical information was modified so that some cases received the same clinical information while, for other cases, the clinical variables were changed. This allowed for data analysis to test the hypothesis that different clinical information would bias observers' interpretations of optic disc characteristics. Number of exact agreements for nerve impression and number of cup/disc ratio agreement ≤ 0.1 cup/disc ratio were tabulated. Results: For the cup/disc ratio and the nerve interpretation measurement there was a 74% and 32% agreement between the three readings respectively. Estimates of cup/disc size and description of the optic disc as glaucomatous were influenced by clinical information. Conclusion: Clinical data such as IOP, visual field, and age affect the subjective clinical measures of the optic disc. Clinicans who observe the optic disc to evaluate the status of glaucoma should be aware that such observations may be biased by the accompanying information.
Keywords: 498 optic disc • 356 clinical (human) or epidemiologic studies: systems/equipment/techniques