Purpose:
Central visual field testing is used to monitor patients with glaucoma and other neurodegenerative diseases. However, it is not ideal for monitoring peripheral disturbances such as defects caused by drug toxicity. The aim of this study was to examine the normal reference for PVF sensitivity and to refine analysis strategies.
Methods:
Automated PVF testing was performed with HFA 60-4 program (60 points) in 33 normal (visual acuity, slit lamp, retinal exam, and tonometry) subjects. Each point was labeled with a NTSI (nasal/temporal/superior/inferior) coordinate system (degrees from fixation) with a measured threshold visual sensitivity (TVS) in decibels. Points were organized into inner, middle, and outer eccentricity rings and divided into 4 zones: superior, inferior, nasal, and temporal. We evaluated TVS by points, ring, and zone. Data were analyzed using one-way ANOVA followed by Tukey’s test.
Results:
Points with the lowest TVS and highest variability (high standard deviation) were located within the nasal area of the outer ring (Table). Points with the highest TVS and least variability were detected in the inner ring and in the temporal area of the middle and outer rings. Mean zone TVS decreased with increasing eccentricity. The superior zone of the middle ring also displayed relatively high data variability.
Conclusions:
The areas with high TVS and least variability that can best reveal peripheral visual abnormalities are all four zones in the inner ring, inferior and temporal zone of the middle ring, and temporal zone of the outer ring. These results may be useful for guiding analysis strategies for detection of peripheral field loss at an early stage when central vision may not yet affected.
Keywords: visual fields • clinical research methodology • drug toxicity/drug effects