T. Michael Nork

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OBJECTIVE To determine whether outer retinal changes occur in chronic, presumed primary open-angle glaucoma (POAG). METHODS The outer retinas from 128 human eyes with a diagnosis of chronic glaucoma (presumably POAG in most cases) and 90 control eyes were examined histologically by 3 masked observers for photoreceptor swelling and loss. Retinas from 9(More)
Both Müller cells and astrocytes have been implicated in the dispute over the histogenesis of massive retinal gliosis. We studied three cases of massive retinal gliosis by light and electron microscopy and immunocytochemistry. Spindle fibrillary glial cells were joined by zonulae adherentes resembling those of the external limiting membrane of the retina.(More)
To test whether the Müller's cell, and not the fibrous astrocyte alone, is an active glial element in proliferative diabetic retinopathy, we developed a method using enzyme histochemical analysis for carbonic anhydrase and immunolabelling for glial fibrillary acidic protein on plastic-embedded sections to detect Müller's cells in degenerated retinas. Four(More)
In one family with low-penetrance retinoblastoma, a germ-line deletion is shared by affected and unaffected, obligate carriers. The deletion encompasses exon 4 of the retinoblastoma gene and corresponds to a mutant protein without residues 127-166. In a second family, RFLP analysis shows that two distant relatives have independently derived mutations. These(More)
OBJECTIVE To determine if there are histopathologic changes in the outer retina that could explain the blue-yellow color confusion previously described following rhegmatogenous retinal detachment in humans. METHODS Ten eyes with traumatic retinal detachments were studied. Eight of the eyes were removed from 2 1/2 to 11 days following trauma. In the(More)
PURPOSE To compare the relative contribution of VEGF and TNF-alpha in the development of laser-induced choroidal neovascularization (CNV) in monkeys and to exploit the feasibility of topical use of suitable antibody fragments for the prevention of experimental CNV. METHODS To induce experimental CNV, small high-energy laser spots were used to treat(More)
The distribution of carbonic anhydrase (CA) among human photoreceptors has been a topic of dispute. In our experiments, by modifying an established enzyme histochemical technique, reproducible staining was observed. Of the cones in the peripheral retina, 91% were positive for CA. The CA-negative (CA-) cones were absent within approximately 8 arc min of the(More)
PURPOSE We report, for the first time to our knowledge, dynamic movements of the vitreous membrane and peripheral choroid during accommodation, and age-related changes in the anterior sclera. METHODS We studied 11 rhesus monkeys (ages 6-27 years) and 12 human subjects (ages 19-65 years). Accommodation was induced pharmacologically in human subjects and by(More)
BACKGROUND AND OBJECTIVE This study examines the clinical response of patients transitioned to aflibercept, the newest anti-VEGF medication, due to persistent evidence of exudation on optical coherence tomography (OCT) despite regular treatment with bevacizumab and/or ranibizumab. PATIENTS AND METHODS Aflibercept was administered to 111 patients(More)
PURPOSE This study was designed to test the hypothesis that photoreceptors are adversely affected in glaucoma. As a measure of this effect, we examined the levels of rod opsin, and red/green and blue cone opsin mRNAs in monkeys with experimental ocular hypertension and glaucoma and in human eyes from donors with diagnosed glaucoma. METHODS Experimental(More)