Multifocal electroretinographical changes in monkeys with experimental ocular hypertension: a longitudinal study

Kremers, Jan; Doelemeyer, Arno; Polska, Elżbieta; Moret, Fabrice; Lambert, Christian; Lambrou, George N.

doi:10.1007/s10633-007-9102-9

Cited by 3 publications

(3 citation statements)

References 21 publications

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“…Recently, Kremers et al [55] reported the results of a study of experimental glaucoma in cynomolgus monkeys in which numerous tests were performed during the period of elevated IOP. Unlike our study, they summed the absolute differences at each signal data point during the 0 to 90 ms interval of K1;no information was obtained regarding the individual wave features (e.g., N1 and P1) or the K2.1.…”

Section: Discussionmentioning

confidence: 99%

Serial multifocal electroretinograms during long-term elevation and reduction of intraocular pressure in non-human primates

et al. 2010

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The purpose of this study was to evaluate the relationship between elevations of intraocular pressure (IOP) and the multifocal electroretinogram (mfERG) in non-human primates. Experimental glaucoma was induced in 4 rhesus and 4 cynomolgus monkeys by laser trabecular meshwork destruction (LTD) in one eye. To evaluate the contribution of ganglion cells to mfERG changes, one monkey of each species had previously underwent unilateral optic nerve transection (ONT). After ≥ 44 weeks of elevation, the IOP was reduced by trabeculectomy in 2 non-transected animals. In the intact (non-transected) animals there was an increase in the amplitude of the early mfERG waveforms (N1 and P1) of the first order kernel (K1) throughout the period of IOP elevation in all of the rhesus, but not all of the cynomolgus monkeys. A species difference was also present as a decrease of the second order kernel, first slice (K2.1) in all of the cynomolgus monkeys but only in 1 of the rhesus monkeys (the 1 with the ONT). Similar IOP effects on the mfERG were seen in the ONT animals. Surgical lowering of IOP resulted in a return of the elevated K1 amplitudes to baseline levels. However, the depressed K2.1 RMS in the cynomolgus monkeys did not recover. These results demonstrate species-specific changes in cone-driven retinal function during periods of elevated IOP. These IOP-related effects can occur in the absence of retinal ganglion cells and may be reversible.

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Section: Discussionmentioning

confidence: 99%

Serial multifocal electroretinograms during long-term elevation and reduction of intraocular pressure in non-human primates

et al. 2010

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“…Multifocal electroretinography testing in nonhuman primates has been carried out with varied anesthetic regimens, e.g., ketamine and xylazine [1-4], ketamine with neuromuscular blocker intravenous infusion [5-6], ketamine or ketamine and xylazine and isoflurane with extraocular muscle blockade [7], and propofol with periodic injections of a neuromuscular blocker [8-10]. Some of the studies [5-6] [8-10] have incorporated the use of a systemic neuromuscular blocker.…”

Section: Introductionmentioning

confidence: 99%

“…Some of the studies [5-6] [8-10] have incorporated the use of a systemic neuromuscular blocker. Our laboratory has used pentobarbital sodium and isoflurane anesthesia without a paralytic agent in previous investigations of the multifocal electroretinogram (mfERG) [11-14] in rhesus and cynomolgus macaques.…”

Section: Introductionmentioning

confidence: 99%

The effect of pentobarbital sodium and propofol anesthesia on multifocal electroretinograms in rhesus macaques

2011

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We compared the suitability of pentobarbital sodium (PB) and propofol (PF) anesthetics for multifocal electroretinograms (mfERGs) in rhesus macaques. mfERGs were collected from 4 ocularly normal rhesus macaques. All animals were pre-anesthetized with intramuscular ketamine (10-15 mg/kg). Intravenous PB induction/maintenance levels were 15 mg/kg/2-10 mg/kg, and for PF, 2-5 mg/kg/6-24 mg/kg/h. There were 3 testing sessions with PB anesthesia and 5-7 testing sessions with PF anesthesia. All PB sessions were carried out before PF. First-order (K1) and second-order (first slice) kernels (K2.1) response density amplitude (RDA), implicit time (IT), and root mean square signal-to-noise ratios (RMS SNR) of the low-frequency (LFC) and high-frequency (HFC) components were evaluated. The use of PF or PB anesthesia resulted in robust, replicable mfERGs in rhesus macaques; however, RMS SNR of K1 LFC in ring and quadrant analyses was significantly larger for PF than for PB. Additionally, K1 RDA under PF was significantly larger than under PB for N1, P1 and P2 components (ring and quadrant), and for N2 (quadrant). PF IT was significantly prolonged (<1 ms) relative to PB IT for N1, P1 (ring) and N1 (quadrant) while PB IT was significantly prolonged (0.8-4.2 ms) relative to PF IT for N2 and P2 (ring and quadrant). K1 HFC and K2.1 LFC did not differ significantly between PB and PF in the ring or quadrant analyses. The response differences found with PB and PF anesthesia likely arise from variable relative effects of the anesthetics on retinal γ-aminobutyric acid (GABAA) receptors, and in part, on glycine and on glutamate receptors. Given the advantages of a stable anesthetic plane with continuous intravenous infusion and a smoother, more rapid recovery, PF is an appealing alternative for mfERG testing in rhesus macaques.

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Multifocal electroretinographical changes in monkeys with experimental ocular hypertension: a longitudinal study

Abstract: OHT does not always lead to ERG changes. Comparisons with fellow eyes using high contrast stimuli are more sensitive to detect changes related to OHT.

Cited by 3 publications

References 21 publications

Serial multifocal electroretinograms during long-term elevation and reduction of intraocular pressure in non-human primates

Serial multifocal electroretinograms during long-term elevation and reduction of intraocular pressure in non-human primates

The effect of pentobarbital sodium and propofol anesthesia on multifocal electroretinograms in rhesus macaques

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