Biomedical subjects

J B Kerrison

Publications and source records attributed to J B Kerrison.

8 recordsLinked to original sources

PubMed1998

Clinical features of autosomal dominant congenital nystagmus linked to chromosome 6p12.

PURPOSE: To describe the clinical features of a large pedigree with autosomal dominant congenital nystagmus linked to chromosome 6p12. METHODS: In a prospective evaluation of 54 living family members in a single pedigree, 21 persons were affected with autosomal dominant congenital nystagmus, and clinical examinations were performed on 14. Selected persons underwent further studies, including electroretinography, scanning laser ophthalmoscopy, nerve fiber layer studies, visual evoked potential studies, and eye movement recordings. RESULTS: Among seven affected persons whose parents were able to report whether the nystagmus was present congenitally, onset at birth was noted in two persons and between 3 and 6 months in five persons. Best-corrected binocular Snellen visual acuity ranged from 20/30 to 20/100, with a mode of 20/50. Strabismus was present in 14 examined patients (36%). Eye movement recordings, performed on five persons, included asymmetric pendular (three), asymmetric pendular combined with dual waveform jerk (one), and unidirectional jerk nystagmus (one). CONCLUSIONS: Autosomal dominant congenital nystagmus represents a disorder with variable expressivity. While onset is typically during infancy, it can be noted at birth. Intrafamilial variation in visual acuity, ocular alignment, and nystagmus waveform suggests a role for modifying influences on expression of disease.

Adult↗

PubMed1997

Clinical spectrum of Leber's hereditary optic neuropathy.

Leber's hereditary optic neuropathy (LHON) is a bilateral subacute optic neuropathy caused by mutations in the mitochondrial genome. Primary mutations are located at nucleotide positions 3460, 11778, and 14484 in genes encoding subunits of Complex 1 of the respiratory chain. Molecular diagnosis has expanded the spectrum of the LHON phenotype and prompted investigation into optic neuropathies due to demyelinating disease, glaucoma, tobacco/alcohol amblyopia, and nutritional optic neuropathy. While mitochondrial mutations are required for LHON disease expression, other genetic or epigentic factors must play a role in disease penetrance and expression. Proposed determinants of disease include heteroplasmy, an X-linked vision loss susceptibility locus, environmental factors, and secondary mitochondrial mutations.

DNA, Mitochondrial↗

PubMed1996

A gene for autosomal dominant congenital nystagmus localizes to 6p12.

Congenital nystagmus is an idiopathic disorder characterized by bilateral ocular oscillations usually manifest during infancy. Vision is typically decreased due to slippage of images across the fovea. As such, visual acuity correlates with nystagmus intensity, which is the amplitude and frequency of eye movements at a given position of gaze. X-linked, autosomal dominant, and autosomal recessive pedigrees have been described, but no mapping studies have been published. We recently described a large pedigree with autosomal dominant congenital nystagmus. A genome-wide search resulted in six markers on 6p linked by two-point analysis at theta = 0 (D6S459, D6S452, D6S465, FTHP1, D6S257, D6S430). Haplotype analysis localizes the gene for autosomal dominant congenital motor nystagmus to an 18-cM region between D6S271 and D6S455.

Chromosome Mapping↗

PubMed1996

Visual field loss following vitreous surgery.

OBJECTIVE: To assess possible causes of visual field loss following vitreous surgery. DESIGN: Charts of 8 patients prospectively identified, who developed visual field loss following vitreous surgery, were reviewed to characterize this newly recognized syndrome and assess possible causes. RESULTS: Two patients had preexisting chronic open-angle glaucoma and 1 had ocular hypertension. Indications for surgery included 4 eyes with macular holes, 1 eye with epiretinal membrane, 2 eyes with rhegmatogenous retinal detachment, and 1 eye with retinal detachment and giant retinal tear. All patients received retrobulbar anesthesia. Seven of 8 patients had fluid/gas exchange with installation of long-acting bubbles. In 1 patient with a macular hole, a small hemorrhage was noted along a vessel coming off the nerve superotemporally while attempting to engage the posterior cortical vitreous intraoperatively. This patient developed an inferior visual field defect. No intraocular pressure (IOP) measurements greater than 26 mm Hg were recorded in any eye perioperatively. Visual field defects included 4 eyes with inferotemporal defects, 2 eyes with inferior altitudinal defects, 1 eye with a cecocentral scotoma, and 1 eye with a superonasal defect. Only 1 patient had worsened visual acuity. A relative afferent pupillary defect was observed in 4 eyes and disc pallor in 5 eyes. CONCLUSIONS: Central or peripheral visual field loss can now be recognized as a possible complication of vitreous surgery. In some cases, a relative afferent pupillary defect and optic disc pallor are present, suggesting that the optic nerve is the site of injury. Possible mechanisms include ischemia due to elevated IOP or fluctuations in IOP, optic nerve damage from retrobulbar injection, direct intraoperative mechanical trauma to the optic nerve, indirect injury from vigorous suction near the optic nerve leading to shearing of peripapillary axons or vessels, or a combination of these. Certain optic nerves may be more susceptible to injury because of preexisting compromise from glaucoma or vascular disease.

Adult↗

PubMed1996

Phacoemulsification after retinal detachment surgery.

PURPOSE: Previous studies have documented a 3% to 15.5% risk of retinal redetachment in eyes with prior scleral buckling procedures that later undergo intracapsular or extracapsular cataract extraction. The authors reviewed the records of patients with a history of retinal detachment (RD) surgery and subsequent phacoemulsification to assess the risk of retinal redetachment and the visual outcomes. METHODS: Forty-seven eyes of 44 patients with a history of scleral buckling surgery who subsequently underwent phacoemulsification were identified. Features found before, during, and after surgery were reviewed. RESULTS: No retinal redetachments occurred on a mean follow-up of 2.3 years. Eyes with RD repair were more myopic than fellow eyes (P=<0.001), had longer axial lengths (P=0.001), had steeper keratometry readings (P=0.03), and had larger differences in K readings between principal meridians (P=0.01). Postoperative visual acuity was 20/40 or better in 72.3% of eyes and 20/80 or worse in 6.4% of eyes. Preexisting macular pathology was responsible for poor outcomes. CONCLUSION: The risk of redetachment after phacoemulsification in eyes with previous RD surgery is low. Despite retinal and cataract surgery, these eyes can achieve useful vision.

Adolescent↗

PubMed1995

Leber hereditary optic neuropathy. Electron microscopy and molecular genetic analysis of a case.

BACKGROUND: Leber hereditary optic neuropathy (LHON) is a mitochondrial genetic disorder characterized by bilateral central visual loss typically in early adulthood. Few histopathologic studies, including ultrastructural and molecular genetic analysis, have been reported. METHODS: Ocular tissue was obtained postmortem from an 81-year-old woman with LHON from the Queensland 1 pedigree characterized by mutations at nucleotide positions 4160 and 14484. Routine histopathologic studies, electron microscopy, electron-probe analysis, and molecular genetic analysis were performed. RESULTS: Marked atrophy of the nerve fiber and retinal ganglion cell layers and optic nerves was present. Results of electron microscopic examination demonstrated 1.2 microns electron-dense, double-membrane-bound inclusions, consisting of calcium by electron-probe analysis, in retinal ganglion cells. The optic nerve was homoplasmic for mutations 4160 and 14484. CONCLUSION: Optic nerve and inner retinal atrophy in LHON may be a result of metabolic mitochondrial dysfunction leading to intramitochondrial calcification. Homoplasmy for mitochondrial mutations 4160 and 14484 in the leukocyte/platelet fraction of whole blood may correlate with homoplasmy in the optic nerve.

Aged↗

PubMed1994

Retinal pathologic changes in multiple sclerosis.

PURPOSE: To describe the ocular pathologic changes in multiple sclerosis (MS), with attention to its effects on the uveal tract and retinal veins. METHODS: Cases of 26 patients with MS and 3 patients with neuromyelitis optica were reviewed; retinal trypsin digestion was performed on remaining wet tissue for 20 of these patients. Eyes were specifically examined for inflammation of the retinal vessels, uveal tract, retina, optic nerve, and pars plana. Specimens were also examined for atrophy of the optic nerve, ganglion cell, and nerve fiber layers. RESULTS: Atrophy of the nerve fiber and ganglion cell layers was present in 73% of the cases with MS and correlated with optic nerve atrophy; choroiditis was present in 11.5%; bilateral cyclitis without other foci of inflammation was present in 1 case; and retinal phlebitis was present in 20% (most of which were only identified after trypsin digestion). Optic nerve inflammation was present in two of the patients with neuromyelitis optica. CONCLUSION: Uveitis and retinal phlebitis are manifestations of MS. Trypsin digestion with microscopic examination is a sensitive method of testing for phlebitis, which may explain why the frequency found in this series is higher than in others. These lesions are similar to the perivenular cuffing that occurs in the central nervous system in MS.

Adult↗

PubMedDate not supplied

Acute loss of vision during pregnancy due to a suprasellar mass.

A pregnant woman presented with headaches, bilateral decreased visual acuity, and a central scotoma with a superotemporal hemianopic defect in the right eye and a superotemporal hemianopic defect in the left eye, and bilateral temporal optic disk pallor. Neuroimaging revealed an intrasellar mass with suprasellar extension. Biopsy of the lesion revealed lymphocytic hypophysitis (LH). Treatment with steroids produced marked improvement in visual function. The clinical presentation of lymphocytic hypothysitis may mimic pituitary adenoma and the diagnosis should be suspected in any pregnant or postpartum patient with an intrasellar or suprasellar mass.

Acute Disease↗