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Biomedical subjects

C D Witherspoon

Publications and source records attributed to C D Witherspoon.

At least 19 recordsLinked to original sources
PubMed1992

Collagen gel contraction by cells associated with proliferative vitreoretinopathy.

The capacities of porcine choroidal fibroblasts, retinal glial cells, and retinal pigment epithelial cells to contract collagen gels in vitro were compared. Experiments with varied cell numbers indicated that glial cells are the most effective, followed by choroidal fibroblasts and retinal pigment epithelial cells. Analysis of the secretory products from cultures of these cell types revealed that retinal pigment epithelial cells synthesize and secrete peptides that promote fibroblast contraction of collagen gels in vitro. The mechanism of action of the retinal pigment epithelial cell-secreted contraction promoter was compared with that found in serum (type A) and secreted by cultured endothelial cells (type B). Like the serum factor, the retinal pigment epithelial cell-secreted factor was not dependent on active protein synthesis by the target cell and must be present continuously to promote contraction.

Animals↗
PubMed1990

Vitrectomy in asteroid hyalosis.

Asteroid hyalosis (AH), a condition in which calcium-lipid complexes form in the collagen meshwork of the vitreous, affects from 0.5% to 0.9% of the general population. In patients with dense AH and visual loss, obscuration of fundus detail on ophthalmoscopy and even on fluorescein angiography may complicate the diagnosis and treatment of underlying posterior segment disease. To evaluate the usefulness of vitrectomy in AH, we reviewed 7 cases of dense AH in 6 patients who underwent vitrectomy in the setting of decreased visual acuity of uncertain cause. Additional diagnoses made following surgery included age-related macular degeneration (ARMD) in 2 eyes, ARMD with associated epiretinal membrane in one eye, and the staging of diabetic retinopathy as proliferative in one eye. Although no major surgical complications occurred in this series, the potential for serious complications exists, and pars plana vitrectomy (PPV) should be considered only after less invasive diagnostic evaluations and therapeutic approaches have been exhausted.

Adult↗
PubMed1990

Endophthalmitis due to Sporothrix schenckii after penetrating ocular injury.

A 13-year-old boy developed endophthalmitis from traumatic inoculation of vegetable material penetrating his right eye. Sporothrix schenckii was morphologically identified from the intraocular fluids. However, repeated attempts to culture the organism proved negative. Seventeen sporotrical endophthalmitis cases have so far been reported, and before this report, only one of them was secondary to trauma. This is the sole eye to our knowledge not only to have escaped enucleation after sporotrical endophthalmitis but to have achieved useful (20/50) vision.

Adolescent↗
PubMed1989

Ocular self-mutilation.

A 32-year-old paranoid schizophrenic man repeatedly stabbed both his eyes with a sharpened wire coat hanger. The patient underwent vitrectomy on each eye approximately 2 1/2 weeks after injury, with multiple retinal defects noted OU. None of the posterior wounds involved the macula or optic disc, and final vision was 20/70 OD and 20/50 OS. Ocular self-mutilation, deliberate and severe self-injury which threatens visual function, is a rare occurrence most often described in acutely psychotic patients. Psychosis may be due to schizophrenia, drug abuse, manic phases of bipolar mood disorders, and depression. A striking number of these patients have delusions with religious and sexual content. They are prone to repeated attempts during the acute psychotic phase and must be monitored closely at this time.

Adult↗
PubMed1989

Eye injury: prevalence and prognosis by setting.

Although an estimated 1 million Americans suffer ocular injuries each year, the setting of injury and its prognostic implications have not been closely examined. Using data compiled by the Eye Injury Registry of Alabama (EIRA) from 514 cases of serious eye injury, we examined the demographics and prognosis of ocular injury by setting of injury. Work-related injuries accounted for only 28% of total injuries, and injuries occurring at home accounted for 27%, followed by situations related to recreation (25%), assault (11%), travel (5%), and "other" (school, unknown, etc) (4%). The poorest initial vision, poorest final vision, and highest rate of enucleation occurred in patients injured by assault, whereas the lowest rate of enucleation and loss of light perception was found in patients who had work-related injuries. Patients in the "other" category had the highest rate of return to 20/100 or better vision.

Accidents, Home↗
PubMed1988

Ocular lawnmower injuries.

In the 10-year period from 1977 to 1987, lawnmowers have been responsible for approximately 70,000 injuries annually with an estimated 5% (3300) involving the eyes. Hyphema, angle recession, and traumatic retinopathy are especially common forms of lawnmower ocular trauma. A series of 14 cases of lawnmower-induced eye injuries is presented along with demographics of the patient population involved. An analysis of various types of lawnmowers currently in use are also included, and preventive measures are suggested.

Accidents, Home↗
PubMed1988

Evolving techniques in the treatment of macular detachment caused by optic nerve pits.

Fourteen patients with macular detachments caused by optic nerve pits were treated for progressive visual loss, cystoid macular changes, or atrophy of the macular retinal pigment epithelium. Photocoagulation of the temporal disc border alone was unsuccessful in two cases but promptly reattached the macula of two patients immobilized after laser surgery. Vitrectomy and gas tamponade improved vision and flattened the macula of three patients over various periods. The detachment recurred in one patient. Prompt and sustained macular reattachment with improved vision was noted after photocoagulation, vitrectomy, and gas tamponade in eight patients, although four required second operations. The prompt reattachment and visual recovery noted in these eight patients surpasses the reported 25% rate of spontaneous resolution.

Bed Rest↗
PubMed1988

Field evaluation of polycarbonate versus conventional safety glasses.

Of all the causes of eye injury, gunshot has recently been cited as resulting in the highest rate of blindness and the lowest rate of visual recovery. Many of these cases are hunting accidents in which safety glasses could have prevented or lessened ocular damage. To evaluate the effectiveness of various types of safety glasses, we fired a Remington automatic shotgun at mannequin heads fitted with one of four types of safety lenses. From a distance of 10 yards, only polycarbonate lenses provided even partial protection. At 30 yards, polycarbonate and heat-treated lenses provided the best protection, whereas chemically treated and CR39 lenses provided significantly less protection. We recommend that hunters using shotguns in areas of poor visibility wear widely available polycarbonate safety glasses as well as "hunter's orange" to minimize their risk of devastating ocular gunshot injury.

Accidents↗
PubMed1987

Bilateral ocular shotgun injury.

We retrospectively studied 14 patients with bilateral ocular shotgun injury in order to determine overall visual prognosis and factors affecting individual prognosis. Although only eight of 28 eyes (29%) in this series recovered visual acuity of 20/100 or better, six of 14 patients (43%) recovered at least 20/100 and eight of 14 patients (57%) recovered visual acuity of at least 20/400. Tissue destruction in the form of severe ocular disorganization or direct injury of optic nerve or macula was the primary limiting factor to visual recovery in 16 of 20 eyes (80%) not recovering to 20/100, while retinal detachment was the limiting factor in only four of these 20 eyes (20%). While extensive ocular disorganization, direct optic nerve or macular injury, no light perception on initial examination, and multiple pellet injuries were predictive of poor outcome, retinal detachment and double perforating injury were not.

Adolescent↗
PubMed1987

Recovery of vision after presumed direct optic nerve injury.

Immediate loss of light perception after direct optic nerve injury is usually irreversible. Our patient sustained presumed direct optic nerve injury because of a shotgun injury with loss of light perception, absent pupillary response, and absent visual-evoked potential. A small pupillary response was noted 12 days after injury, light perception returned by 15 days, and visual acuity was 20/100 at 4 months. A variety of pathophysiologic mechanisms may lead to visual loss after direct optic nerve injury. It is important to recognize that blindness is not always permanent in these cases despite the results of initial clinical and electrophysiologic testing.

Adolescent↗
PubMed1987

Eye Injury Registry of Alabama (preliminary report): demographics and prognosis of severe eye injury.

Each year an estimated 1.3 million Americans suffer eye injuries. There is little information in the literature regarding the prevalence, demographic characteristics, and prognosis of these patients. The Eye Injury Registry of Alabama (EIRA) serves as the first and only statewide system of its kind for the collection of information on serious eye injuries. We have analyzed 736 cases of serious eye injury (injury involving permanent structural or functional change) accumulated by the EIRA between August 1982 and May 1986. Prognosis was found to be related to early diagnosis and initial vision. Individuals with follow-up vision of 20/40 or better were found in all early diagnostic groups, and 13% of patients with no light perception on initial examination had some improvement on follow-up. The worst visual prognosis was among those patients suffering blunt eyeball rupture, of whom 40% had no light perception and 25% regained vision of 20/100 or better.

Accidents, Home↗