Biomedical subjects

D R Guyer

Publications and source records attributed to D R Guyer.

61 records · Page 4Linked to original sources

PubMed1986

Periodic alternating nystagmus associated with albinism.

We examined a 73-year-old woman with the rare association of albinism and (presumably) congenital periodic alternating nystagmus. The mechanism of the nystagmus in this case is uncertain. Anomalous retinogeniculate pathways have been documented in albino animals. Periodic alternating nystagmus might occur in some patients with albinism if there are also anomalies in the pathways conveying visual information to the cerebellum and brainstem.

Aged↗

PubMed1985

The risk of cerebrovascular and cardiovascular disease in patients with anterior ischemic optic neuropathy.

Of 217 patients in whom anterior ischemic optic neuropathy (AION) was diagnosed during the period from 1975 to 1985, verifiable medical information was obtained for 212 (98%). Over a median follow-up period of three years, no group of patients had an increased mortality rate over that of age-, sex-, and race-matched controls; however, patients with "idiopathic" AION and patients with systemic hypertension who developed nonarteritic AION had a statistically significant increased risk of experiencing cerebrovascular events and myocardial infarctions compared with appropriately matched control groups. In view of the findings of our study, we suggest that patients with idiopathic AION and hypertensive patients who develop nonarteritic AION undergo a complete physical examination, cardiac evaluation, tests of carotid artery patency, and careful medical follow-up to attempt to prevent subsequent cerebrovascular or cardiovascular events.

Adult↗

PubMed1985

Visual function following optic canal decompression via craniotomy.

Visual function was assessed in 15 eyes of 11 patients who underwent unilateral (seven patients) or bilateral (four patients) optic canal decompression for presumed compressive optic neuropathies. Both immediate and long-term postoperative vision was evaluated in all eyes. Over 90% of the eyes that had undergone nerve decompression had either the same or improved visual acuity and visual field immediately following surgery. In this group of patients there were no deaths and there was only one postoperative complication, a transient dysphasia caused by an epidural hematoma that was evacuated. Long-term follow-up evaluations revealed that most of the eyes retained their immediate postoperative visual function or showed gradual visual improvement with time. The results of this series as well as a review of the available literature indicate that optic canal decompression via craniotomy can be a safe procedure and that it appears to have lasting visual benefit in many patients.

Adolescent↗

PubMed1984

Bilateral extreme microphthalmos.

A case of bilateral extreme microphthalmos is reported. Autopsy of a one-day-old full-term female revealed multiple congenital anomalies which included occipital encephalocele, cleft palate, hips which could not be abducted, long fingers and toes, and cardiovascular malformations. Chromosomal analysis showed a normal 46 XX karyotype. Ocular findings in this case included clinical anophthalmos with bilateral fused eyelids, optic nerve aplasia, absent cornea and lens, and retinal dysplasia. The distinctions between anophthalmos and varying degrees of microphthalmos are discussed. The insult causing abnormal development in this case appears to have occurred during the first trimester of pregnancy. There were no prenatal or delivery complications. A genetic abnormality was considered since two older siblings have birth defects. Also discussed is the possibility of a combined genetic and environmental etiology.

Abnormalities, Multiple↗

PubMedDate not supplied

Macular hole.

A macular hole is a full-thickness defect of retinal tissue involving the anatomic fovea, thereby affecting central visual acuity. Macular holes have been associated with myriad ocular conditions and originally were described in the setting of trauma. The pathogenesis of idiopathic, age-related macular holes remains unclear despite a litany of theories. Recently, Gass has described an updated biomicroscopic classification of macular holes and postulated that tangential vitreous traction may play a role. Cellular components surrounding the rim of macular holes may also contribute tangential traction forces and elevate the rim. Pseudomacular holes may be mistaken for macular hole lesions, despite careful clinical examination. Careful biomicroscopic examination with a contact lens and use of the Watzke and laser aiming beam tests help to ensure accurate diagnosis. Newer imaging technology, such as optical coherence tomography, helps distinguish true macular holes from pseudoholes and may provide additional insight into the pathogenesis of this condition. Surgical management with or without pharmacosurgical adjuncts can improve vision in select cases. The most common surgical complication is progressive lens opacification in phakic patients.

Aged↗

PubMedDate not supplied

Clinicopathologic correlation of krypton and argon laser photocoagulation in a patient with a subfoveal choroidal neovascular membrane.

Krypton-red laser photocoagulation for choroidal neovascular membranes has been shown to produce inner retinal sparing in contrast to argon blue-green or argon-green laser photocoagulation, which causes full-thickness retinal destruction. However, previous histopathologic reports have involved only primates or humans without known macular degeneration. Clinicopathologic features of a case in which a human eye with a choroidal neovascular membrane, associated with age-related macular degeneration, was photocoagulated on four occasions with the argon-green and krypton-red lasers are presented. The results of this study confirm previous reports of the inner retinal sparing noted with krypton-red laser photocoagulation in comparison with argon blue-green or argon-green laser photocoagulation.

Aged↗

PubMedDate not supplied

Indocyanine green videoangiography: current status.

Indocyanine-green (ICG) angiography has experienced a rejuvenated interest in the past few years because of improvements in technological systems. After three years of experience with evolving digital technology, we have reviewed our experience to provide an update on potential applications in a variety of choroidopathies. Based on 3,000 cases studied with ICG angiography, we evaluated the diagnostic value of the procedure in choroidal abnormalities including ischemic, tumor, idiopathic, inflammatory, and neovascularized diseases. ICG angiography is still of limited clinical value in ischemic diseases because of a relatively poor imaging potential for the choriocapillaris. The procedure has not yet provided information which is of significant value in the evaluation and management of choroidal tumors. Valuable information has been provided on the fundamental pathogenesis of certain idiopathic diseases. Preliminary experience in inflammatory diseases is very promising. A genuine advance in imaging of "occult"-choroidal neovascularization has been provided by the diagnostic technique. Improved delineation of these vessels offers opportunities for ICG-guided laser treatment.

Choroid Diseases↗