Influence of visual field results in the glaucoma diagnosis

Abstract Objective: To determine the influence of visual field results in the diagnosis of glaucoma. Methods: A questionnaire with ophthalmologists was conducted where slides of a digital photograph of the optic disc and computerized visual field exam were presented.(Physicians were instructed to answer whether glaucoma was observed in each of the slides). No other information was given to those examiners. Half of the patients had glaucoma with corresponding visual field, and the other half had physiological cupping and normal visual field. The slides were equally divided between retinography and corresponding visual field (same patient) and exams randomly exchanged, where an optic disc of glaucoma with a normal visual field was placed, and vice-versa. The order in which the slides were presented was also randomized. Results: Forty slides were evaluated by 29 ophthalmologists. No glaucoma specialist was included. The overall agreement among the examiners (Kappa) was 0.270 ± 0.281, and 0.261 ± 0.238 for the exams of the same eye and was 0.274 ± 0.217 from the slides with the exams changed (p=0.4). The diagnosis was made correctly in glaucoma patients with corresponding visual field exam in 66.89% of the cases, and in 66.20% of patients with physiological cupping. When the exams were exchanged, the results dropped to 34.13% and 35.86%, respectively (p<0.001 for both). Conclusion: Visual field results may influence the diagnosis of glaucoma by non-glaucoma specialists.