Standardized full-field electroretinography in rabbits.

Wallenberg Retina Center, Department of Ophthalmology, Lund University Hospital, Lund, Sweden.
Documenta Ophthalmologica (Impact Factor: 1.54). 10/2004; 109(2):163-8. DOI: 10.1007/s10633-004-3924-5
Source: PubMed

ABSTRACT We present a procedure for full-field ERG recording in rabbits, based on the human ERG standards published by the International Society for Clinical Electrophysiology of Vision (ISCEV). Following initial pilot experiments, six animals aged 3 months and 11 animals between 1 and 2 years were investigated. All animals displayed well detectable and reproducible separate cone and rod responses under appropriate stimulus conditions. The b-wave was smaller in young animals than in old, but there were no similar differences in the b-wave implicit times. The animals had to be lightly sedated, which was shown to have no adverse effects on the recordings. Standard deviations of normalized adult rabbit recordings were comparable to human recordings. The measurements were less precise in young animals. We suggest that our procedure is well suited for further scientific studies in this animal model.

  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate and describe the cone function in the normal and lesioned rabbit retina using the multifocal electroretinogram (mfERG). Twelve animals underwent a two-port vitrectomy with subsequent retinectomy in one eye. The area of removed retina was located in the nasal part of the visual streak, and measured approximately 1-2 disc diameters. Both eyes were investigated with mfERG preoperatively and up to 13 weeks postoperatively. A Burian-Allen bipolar contact lens with built-in infrared emitters was used to visualize the retina during the recordings. The averages of the trace array amplitudes in the lower nasal and temporal quadrants were calculated and statistically analyzed at the different time intervals. All eyes were examined histologically with hematoxylin and eosin staining. The retina could be visualized during the mfERG examinations. Postoperatively, up to 3 weeks, amplitudes were reduced over the entire stimulated area in retinectomized eyes (2.20 microV+/-1.22 SD) as compared with preoperative examinations (3.40 microV+/-1.00 SD). After 7 weeks the amplitudes in the quadrant including the retinectomized area remained low (2.62 microV+/-1.02 SD), whereas they were higher than at earlier postoperative examinations in the lower unlesioned temporal quadrant (3.56 microV+/-0.71 SD) with a statistical difference between the quadrants. At 13 weeks this was even more pronounced. In unoperated eyes, the area corresponding to the visual streak displayed significantly higher amplitudes than the area superior to the myelinated streak, corresponding well to the cone distribution. High amplitudes were also detected in the area of the myelinated nerve fibers and optic nerve head, most likely as a result of scattering light. In histological sections, the retinectomized area had a diameter of 1-3 mm. This study shows that the mfERG technique can be used as a tool in experimental retinal research involving the rabbit eye, where retinal lesions down to at least 1 mm can be detected. One difficulty involves scattering light emanating from the relatively large optic disc and the myelinated nerve fibers, which makes the use of a mfERG system, in which the fundus can be visualized during stimulation, mandatory.
    Albrecht von Graæes Archiv für Ophthalmologie 02/2006; 244(1):83-9. · 1.93 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In people, retinal detachment often leads to a significant loss in cone-based vision. Most of the animal models commonly used for studying the consequences of retinal detachment have rod-dominated retinas. The purpose of this investigation was to evaluate the possibility that the ground squirrel, a rodent with a heavily cone-dominated retina, might provide a useful model for studying cone function in retinal detachment. Corneal ERGs were recorded from ground squirrels for large-field temporal modulations presented on a computer-controlled color monitor. Modulations were chosen to selectively stimulate either of the two classes of cone found in the ground squirrel retina. Under these test conditions, large and reliable cone ERGs could be readily recorded. In animals in which the retina had been surgically detached, the loss of cone signal was directly related to the number of cones in the detachment zone relative to the total cone population and that relationship did not differ for short-wavelength sensitive (S) and middle-wavelength sensitive (M) cones. Surgical reattachment produced a progressive recovery of cone-based signals. The ground squirrel seems likely to provide a useful animal model for studying the dynamics of cone function in retinal detachment and subsequent events.
    Documenta Ophthalmologica 02/2002; 104(1):119-32. · 1.54 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to determine electroretinographic parameters according to the standard protocol from the International Society for Clinical Electrophysiology of Vision (ISCEV) in healthy preterm infants with normal fundus. Seventeen healthy preterm infants with normal fundus were recruited and divided in two age groups: 3-week group, nine infants with mean adjusted age at test = 2.67 +/- 0.92 weeks and 8-week group, eight infants with mean adjusted age at test = 7.92 +/- 1.72 weeks. Full-field ERGs were obtained with a Burian-Allen bipolar contact lens electrode from the anesthetized cornea in one eye, through a fully dilated pupil after 30 min of dark adaptation. The standard ISCEV protocol was used and the following responses were recorded: rod, maximal, oscillatory potentials, cone and 30 Hz flicker. Median values and 1st, 5th, 95th and 99th percentiles for amplitude and implicit time are described for both age groups. There was statistically larger amplitude for 30 Hz flicker (t = 2.191; p = 0.046) and for cone response (t = 2.307; p = 0.044) in the 8-week-old group. Statistically shorter implicit times were found in 8-week group for rod response (t = 3.219; p = 0.015), cone response (t = 2.839; p = 0.016) and flicker response (t = 3.326; p = 0.005). Shortening of implicit time was evident in the older group of preterms and this finding is consistent with other maturational studies confirming the anatomical and functional development of the photoreceptors. Medians and ranges between the 1st and 99th and the 5th and 95th percentiles can be used as a baseline for future comparisons with infants with ROP.
    Documenta Ophthalmologica 12/2003; 107(3):243-9. · 1.54 Impact Factor