ABSTRACT
Purpose:
The purpose of this study was to investigate the utility of steady
state pattern electroretinogram (ss-PERG) in detecting
retinal ganglion cell (RGC) dysfunction in
glaucoma suspects (GS)
who had normal 24-2 Humphrey
Visual Fields (HFA). Materials and
Methods:
This was a prospective
cohort study of GS
patients who were identified based on
optic disc appearance with normal HFAs.
Patients received a complete
eye examination, standard automated
perimetry (SAP),
optical coherence tomography (OCT), and ss-PERG measurements. The ss-PERG
parameters,
Magnitude (Mag),
Magnitude D (MagD), and MagD/Mag ratio, were examined, along with their relationships between HFA and OCT measurements.
Results:
Twenty-five
patients were included in this study, with a total of 49
eyes. Fifteen
eyes had abnormal ss-PERG
parameters and when compared to GS
eyes with normal ss-PERG
parameters, there were significant differences in HFA 24-2,
retinal nerve fiber layer (RNFL) thickness, and
ganglion cell layer and inner plexiform layer (GCL + IPL) thickness. All ss-PERG
parameters were significantly correlated with 24-2 VF mean deviation (MD) and
visual field index (VFI), as well as 10-2 VF MD after controlling for age,
sex,
intraocular pressure, central corneal thickness, and spherical equivalent. When controlled for age, spherical equivalent, and IOP, MagD/Mag ratio significantly contributed to the variance in average GCL + IPL thicknesses, whereas 24-2 VF MD and 10-2 VF MD did not. MagD/Mag ratio also significantly accounted for variance in all macular GCL + IPL sectors, while 10-2 VF MD did not.
Conclusions:
ss-PERG has significant correlations with HFA global indices and was predictive of GCL + IPL thickness in GS
patients.
Clinical Significance. ss-PERG may serve as a useful functional tool for detecting and measuring RGC dysfunction in GS. It appears to be more sensitive than HFA in the
detection of early changes in GCL + IPL thicknesses and may be helpful to use in conjunction with current diagnostic studies to improve the
ability of
monitoring GS progression.