Comparison between broadband and monochromatic photopic negative response in full-field electroretinogram in controls and subjects with primary open-angle glaucoma
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A prospective, cross-sectional, case–control study was conducted to investigate the role of broadband and monochromatic photopic negative response (PhNR) of the full-field flash electroretinogram (ERG) in the evaluation of ganglion cell damage in primary open-angle glaucoma (POAG) subjects.
Subjects with POAG and age-matched normal subjects were recruited from the outpatient department of a tertiary eye care center in South India. A total of 25 patients with POAG and 50 age-matched normal subjects were recruited. ERG was recorded using broadband (3.5 cd.s/m2 white stimulus on 10 cd/m2 white background) and monochromatic (3.5 cd.s/m2 red stimulus on 10 cd/m2 blue background and 1 cd.s/m2 blue stimulus on 10 cd/m2 yellow background) stimuli.
The reduction in PhNR amplitude in POAG compared to normal individuals was higher in red-on-blue PhNR [26.37 µV; p < 0.001, confidence interval (CI) 19.34 to 33.4] as compared to broadband stimuli (16.41 µV; p < 0.001, CI 8.68 to 24.13), and blue on yellow (21.96 µV; p < 0.001, CI 10.12 to 33.8). Red-on-blue PhNR amplitudes correlated better with mean deviation (MD; r = − 0.66, p < 0.05), pattern standard deviation (PSD; r = − 0.4, p = 0.04), visual field index (VFI; r = − 0.58, p < 0.05), and retinal nerve fiber layer thickness (r = − 0.67, p < 0.05) in comparison with broadband and monochromatic blue-on-yellow PhNR. Receiver operating characteristic curve revealed largest area under the curve (0.89) in red-on-blue PhNR compared to broadband (0.76) and blue on yellow (0.74). The sensitivity and specificity was also higher in red-on-blue PhNR (72% and 80%, respectively) as compared to the other stimuli (sensitivity and specificity of broadband 0.68 and 0.7, blue on yellow 0.64 and 0.7, respectively).
Correlation of PhNR with Humphrey visual field parameters and retinal nerve fiber layer thickness showed that red-on-blue PhNR can be a useful additional tool for clinical assessment of retinal ganglion cell dysfunction in glaucoma patients. Red-on-blue PhNR was more sensitive as compared to white-on-white and blue-on-yellow PhNR in identifying ganglion cell dysfunction and correlates well with other structural and functional tests for glaucoma such as MD, PSD, VFI, and RNFL thickness.
KeywordsFull-field electroretinogram Photopic negative response Broadband ERG Monochromatic ERG Primary open-angle glaucoma
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interests.
Statement of human rights
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.
Statement on the welfare of animals
This article does not contain any studies with animals performed by any of the authors.
Informed consent was obtained from all individual participants included in the study.
- 3.Blumenthal EZ, Sample PA, Berry CC, Lee AC, Girkin CA, Zangwill L, Caprioli J, Weinreb RN (2003) Evaluating several sources of variability for standard and SWAP visual fields in glaucoma patients, suspects, and normals. Ophthalmology 110(10):1895–1902. https://doi.org/10.1016/S0161-6420(03)00541-4 CrossRefGoogle Scholar
- 4.JunoyMontolio FG, Wesselink C, Gordijn M, Jansonius NM (2012) Factors that influence standard automated perimetry test results in glaucoma: test reliability, technician experience, time of day, and season. Invest Ophthalmol Vis Sci 53(11):7010–7017. https://doi.org/10.1167/iovs.12-10268 CrossRefGoogle Scholar
- 5.Kutzko KE, Brito CF, Wall M (2000) Effect of instructions on conventional automated perimetry. Invest Ophthalmol Vis Sci 41(7):2006–2013Google Scholar
- 11.Rangaswamy NV, Frishman LJ, Dorotheo EU, Schiffman JS, Bahrani HM, Tang RA (2004) Photopic ERGs in patients with optic neuropathies: comparison with primate ERGs after pharmacologic blockade of inner retina. Invest Ophthalmol Vis Sci 45(10):3827–3837. https://doi.org/10.1167/iovs.04-0458 CrossRefGoogle Scholar
- 17.Drasdo N, Aldebasi YH, Chiti Z, Mortlock KE, Morgan JE, North RV (2001) The s-cone PHNR and pattern ERG in primary open angle glaucoma. Invest Ophthalmol Vis Sci 42(6):1266–1272Google Scholar
- 19.Colotto A, Falsini B, Salgarello T, Iarossi G, Galan ME, Scullica L (2000) Photopic negative response of the human ERG: losses associated with glaucomatous damage. Invest Ophthalmol Vis Sci 41(8):2205–2211Google Scholar
- 21.Machida S, Gotoh Y, Kaneko M, Toba Y, Ohtaki A, Kurosaka D (2007) Comparison of the photopic negative response obtained under different recording conditions in glaucomatous eyes. Invest Ophthalmol Vis Sci 48(13):215–221Google Scholar