Henry Liu1,2, Xiang Ji1,3,4, Sabrina Dhaliwal1, Syeda Naima Rahman1, Michelle McFarlane1, Anupreet Tumber1, Jeff Locke1, Tom Wright5, Ajoy Vincent6,7,8, Carol Westall9,10,11. 1. Ophthalmology and Vision Sciences, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada. 2. Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada. 3. Institute of Medical Science, University of Toronto, Toronto, ON, Canada. 4. Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada. 5. Kensington Eye Institute, Kensington Health Centre, Toronto, ON, Canada. 6. Ophthalmology and Vision Sciences, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada. ajoy.vincent@sickkids.ca. 7. Institute of Medical Science, University of Toronto, Toronto, ON, Canada. ajoy.vincent@sickkids.ca. 8. Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada. ajoy.vincent@sickkids.ca. 9. Ophthalmology and Vision Sciences, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada. carol.westall@sickkids.ca. 10. Institute of Medical Science, University of Toronto, Toronto, ON, Canada. carol.westall@sickkids.ca. 11. Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada. carol.westall@sickkids.ca.
Abstract
PURPOSE: The full-field electroretinogram (ff-ERG) is a widely used clinical tool to evaluate generalized retinal function by recording electrical potentials generated by the cells in the retina in response to flash stimuli and requires mydriasis. The purpose of this study was to determine the intra-visit reliability and diagnostic capability of a handheld, mydriasis-free ERG, RETeval (LKC Technologies, Gaithersburg, MD, USA), in comparison with the standard clinical ff-ERG by measuring responses recommended by the International Society for Clinical Electrophysiology of Vision (ISCEV). METHODS: This prospective, cross-sectional study included 35 patients recruited at the Hospital for Sick Children (median age = 17, range 11 months-69 years) who had undergone a clinical ff-ERG according to ISCEV standards. For RETeval (n = 35), pupils were undilated in most (n = 29) and sensor strip electrodes were placed under the inferior orbital rim. Stimulus settings on RETeval were equivalent to those used in the clinical ERG. Fifty-seven control participants (median age = 22, range 8-65 years) underwent undilated RETeval ERG to establish standard values for comparison. Patient waveform components with amplitudes < 5th percentile, or implicit times > 95th percentile of normal relative to control data were classified as abnormal for the RETeval system. RESULTS: The RETeval system demonstrated a high degree of within-visit reliability for amplitudes (ICC = 0.82) and moderate reliability for implicit times (ICC = 0.53). Cohen's Kappa analysis revealed a substantial level of agreement between the diagnostic capability of RETeval in comparison with clinical ff-ERG (k = 0.82), with a sensitivity and specificity of 1.00 and 0.82, respectively. Pearson's correlations for clinical ERG versus RETeval demonstrated a positive correlation for amplitudes across the rod (r = 0.65) and cone (r = 0.74) ERG waveforms. Bland-Altman plots showed no bias between the mean differences across all amplitude and implicit time parameters of the two systems. CONCLUSIONS: The present study demonstrated that RETeval is a reliable tool with reasonable accuracy in comparison with the clinical ERG. The portable nature of RETeval system enables its incorporation at resource-limited centers where the ff-ERG is not readily available. The avoidance of sedation and pupillary dilation are added advantages of RETeval ERG.
PURPOSE: The full-field electroretinogram (ff-ERG) is a widely used clinical tool to evaluate generalized retinal function by recording electrical potentials generated by the cells in the retina in response to flash stimuli and requires mydriasis. The purpose of this study was to determine the intra-visit reliability and diagnostic capability of a handheld, mydriasis-free ERG, RETeval (LKC Technologies, Gaithersburg, MD, USA), in comparison with the standard clinical ff-ERG by measuring responses recommended by the International Society for Clinical Electrophysiology of Vision (ISCEV). METHODS: This prospective, cross-sectional study included 35 patients recruited at the Hospital for Sick Children (median age = 17, range 11 months-69 years) who had undergone a clinical ff-ERG according to ISCEV standards. For RETeval (n = 35), pupils were undilated in most (n = 29) and sensor strip electrodes were placed under the inferior orbital rim. Stimulus settings on RETeval were equivalent to those used in the clinical ERG. Fifty-seven control participants (median age = 22, range 8-65 years) underwent undilated RETeval ERG to establish standard values for comparison. Patient waveform components with amplitudes < 5th percentile, or implicit times > 95th percentile of normal relative to control data were classified as abnormal for the RETeval system. RESULTS: The RETeval system demonstrated a high degree of within-visit reliability for amplitudes (ICC = 0.82) and moderate reliability for implicit times (ICC = 0.53). Cohen's Kappa analysis revealed a substantial level of agreement between the diagnostic capability of RETeval in comparison with clinical ff-ERG (k = 0.82), with a sensitivity and specificity of 1.00 and 0.82, respectively. Pearson's correlations for clinical ERG versus RETeval demonstrated a positive correlation for amplitudes across the rod (r = 0.65) and cone (r = 0.74) ERG waveforms. Bland-Altman plots showed no bias between the mean differences across all amplitude and implicit time parameters of the two systems. CONCLUSIONS: The present study demonstrated that RETeval is a reliable tool with reasonable accuracy in comparison with the clinical ERG. The portable nature of RETeval system enables its incorporation at resource-limited centers where the ff-ERG is not readily available. The avoidance of sedation and pupillary dilation are added advantages of RETeval ERG.
Authors: Daphne L McCulloch; Michael F Marmor; Mitchell G Brigell; Ruth Hamilton; Graham E Holder; Radouil Tzekov; Michael Bach Journal: Doc Ophthalmol Date: 2014-12-14 Impact factor: 2.379
Authors: Jia Yue You; Allison L Dorfman; Mathieu Gauvin; Dylan Vatcher; Robert C Polomeno; John M Little; Pierre Lachapelle Journal: Doc Ophthalmol Date: 2022-10-23 Impact factor: 1.854
Authors: Anna M Waldie; Angharad E Hobby; Isabelle Chow; Elisa E Cornish; Mathura Indusegaran; Aleksandra Pekacka; Phuc Nguyen; Clare Fraser; Alison M Binns; Miles R Stanford; Christopher J Hammond; Peter J McCluskey; John R Grigg; Omar A Mahroo Journal: Transl Vis Sci Technol Date: 2022-05-02 Impact factor: 3.048