G R Dunkelberger

Learn More
We measured the number and size of retinal ganglion cells from six human eyes with glaucoma. In each, the histologic findings were correlated with visual field results. Five age-matched normal eyes were studied for comparison. In general, there were fewer remaining large ganglion cells in retinal areas with atrophy. In the perifoveal area, however, no(More)
To determine whether glaucoma selectively injures a particular size of optic nerve fiber (and its cell body), we induced chronic experimental glaucoma in one eye each of ten monkeys. With automated image analysis, the number and diameter of optic nerve fibers were compared between each glaucomatous eye and its normal fellow eye. Fibers larger than the(More)
ERG and VEP responses to counterphase checkerboard stimuli were obtained from cynomolgus monkeys with monocular glaucoma induced by laser photocoagulation of the trabecular meshwork. The glaucomatous eyes showed reductions of PERG amplitude that were directly related to the histologically defined nerve damage. VEP amplitudes were also reduced in the(More)
We used light microscopic autoradiography to determine the time course of cellular incorporation of tritiated thymidine (a correlate of cell division) following glaucoma filtration surgery in seven eyes of four cynomolgus monkeys with experimental glaucoma. Incorporation of tritiated thymidine was detected as early as 24 hours postoperatively. Peak(More)
Eighteen eyes of 12 persons with chronically elevated intraocular pressure (IOP) were studied histologically to determine the number and diameter of optic nerve fibers. In some eyes, automated perimetry had been performed. Optic nerve fibers larger than the mean diameter were killed more rapidly than smaller fibers, although no fiber size was completely(More)
Thirty-two areas located in the temporal midperipheral retina were evaluated in whole-mount preparations from four monkeys with monocular experimental glaucoma. Diameter frequency distributions of remaining ganglion cells in the glaucomatous eye were compared with corresponding areas in the normal fellow eye. Large cells were significantly more vulnerable(More)
The authors used the Humphrey Retinal Analyzer to study the effect of acute changes in intraocular pressure (IOP) on the topography of the optic nerve head in normotensive and hypertensive eyes of cynomolgus monkeys. Chronically elevated IOP was produced monocularly in monkeys by argon laser angle treatment. In 8 hypertensive eyes, the mean IOP of 51 mmHg(More)
Unilateral glaucomatous optic neuropathy and optic nerve transections were produced in cynomolgus monkeys, and the optic nerve heads were examined by light and electron microscopic immunohistochemistry. Glaucomatous nerve heads showed increased labeling for collagen type IV along the margins of beams in the lamina cribrosa, due to accumulation of basement(More)
Using an automated image analysis system, cross-sections from optic nerves of 17 normal cynomolgus monkeys were examined. The number of nerve fibers, their density, and the distribution of their diameters for whole nerves and for various regions of the nerve cross-section were estimated. The mean total number of fibers in the optic nerve was 1.2 million.(More)
The authors counted axons in one optic nerve from each of 28 juvenile and aged rhesus monkeys using an automated image analysis system. All nerves were fixed immediately after death and treated identically. Animals ranged in age from 1 1/2 to 29 yr, which correlates with a human age range of 4 1/2-87 yr. Mean axonal number for all specimens was 1,117,859.(More)