Reproducibility of Pattern Electroretinogram in Glaucoma Patients with a Range of Severity of Disease with the New Glaucoma Paradigm
Presented in part at: American Academy of Ophthalmology 109th annual meeting, October 2005, Chicago, Illinois.
Received 16 January 2007; received in revised form 31 July 2007; accepted 10 August 2007. published online 01 November 2007.
Purpose
To determine the reproducibility of the pattern electroretinogram with the new Pattern Electroretinogram for Glaucoma (PERGLA) recording paradigm in glaucoma patients with a range of severity.
Design
Experimental study.
Participants
Fifty-three glaucoma patients were recruited for the study (mean age ± standard deviation [SD], 69±11 years). Their mean deviation (MD) global indices on static automatic perimetry ranged from 2.16 to −31.36 decibels (mean MD, −9.05).
Intervention
All patients had pattern electroretinogram recordings done 5 times by the same operator, on 5 different days with the standardized PERGLA paradigm.
Main Outcome Measures
Pattern electroretinogram amplitude (microvolts), phase (π radians), response variability (coefficient of variation [CV] = SD/mean × 100) of amplitude and phase of 2 partial averages that build up the pattern electroretinogram waveform, interocular asymmetry in amplitude and phase (in terms of the CV generated by the pattern electroretinogram software), signal-to-noise (S/N) ratio, SDs, CV, and intraclass correlation coefficient (ICC). All analyses were done on one eye of each subject, except when interocular asymmetry was studied.
Results
The CVs of intrasession variabilities in amplitude and phase were 12.08% and 2.20%, respectively, and those of intersession variabilities were 20.82% and 4.17%. The pattern electroretinogram produced intersession ICCs in amplitude and phase of 0.791 and 0.765, respectively. These ICCs were significantly higher than the ICCs for pattern electroretinogram interocular asymmetry in amplitude and phase (0.659 [P<0.05] and 0.571 [P<0.05], respectively). On average, the pattern electroretinogram S/N ratio in glaucomatous patients was about 5:1.
Conclusions
The reproducibility of PERGLA in glaucomatous patients is sufficiently good for it to be considered a useful complementary clinical tool. Being more reproducible, direct measures of amplitude and phase should be more useful in monitoring progression than interocular asymmetry comparisons.
Available online: November 5, 2008.
1Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida.
2Centre Hospitalier Affilié Universitaire (Hôpital St-Sacrement), Department of Ophthalmology, Unité de Recherche en Gériatrie de l'Université Laval, Laval University, Quebec, Canada.
Correspondence to Marie-Josée Fredette, MD, Centre Hospitalier Affilié Universitaire (Hôpital St-Sacrement), URGUL, 1050, chemin Ste-Foy, Local L2-27, Quebec, Quebec, G1S 4L8, Canada.
Manuscript no. 2007-58.
Supported in part by the National Eye Institute, Bethesda, Maryland (research grant no. RO1 EY014957 [VP], core grant no. P30 EY014801); an unrestricted grant from Research to Prevent Blindness, Inc., New York, New York; an unrestricted donation from Zeiss-Meditec-Humphrey, Dublin, California; an unrestricted donation from Allergan, Inc., Irvine, California; an investigator-initiated grant from Pfizer, Inc., New York, New York; and a fellowship scholarship from Laval University.
All authors except Dr Porciatti have no financial or proprietary interest in any products or devices mentioned in the article. Dr Porciatti developed the Pattern Electroretinogram for Glaucoma paradigm and has a financial interest with Lace Elettronica, Pisa, Italy.
ABSTRACT