Abstract
Purpose: :
The visual field (VF) is a major additional exam for the follow-up of patients suffering from chronic glaucoma. Its interpretation is made difficult because of a great number of parameters. The objective of our study is to analyze the reading pattern of Humphrey type VF results according to the examiner level of training.
Methods: :
Two groups of subjects have been constitued: one group of residential students (n=22) and one group of senior ophthalmologists (n=11). Ten 30-2 Humphrey type VF from chronic glaucomatous patients have been interpreted by the two groups of participants. During the interpretation, the participants had to answer questions concerning either the visual field reliability (6 VF) or its severity (4 VF).The recording of the examiner's eye movements was realized with a video-oculometer manufactured by Metrovision (France).The analysis was based on the chronological sequence of exploration of VF results and on the time spent on each VF zone.
Results: :
Each VF was divided into 8 zones: Zone 1 (administrative and reliability criterion), Zone 2 (sensitivity map), Zone 3 (Grey scale map), Zones 4 and 5 (maps of total and individual sensitivity deviations), Zones 6 and 7 (maps of total and individual probabilities), Zone 8 (average deficit and PSD indexes).For the chronological sequence of exploration, both groups followed a logical reading pattern (administrative criterions followed by reliability criterions then by objective values of alterations).The time needed for the analysis of zones 1,2,7 and 8 of the VF was significantly less for the senior group compared to the residential students group [4330 +/- 200 ms vs 8630 +/- 770 ms;p<0,05]
Conclusions: :
In this study, the VF reading pattern did not depend on the clinical experience of the practitioner. However, there was a significant difference in the time needed for the exploration. Experienced practitioners did have a faster evaluation of each explored zone.