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Biomedical subjects

W J Stark

Publications and source records attributed to W J Stark.

At least 181 records · Page 10Linked to original sources
PubMed1983

Coagulation properties of intraocular humors and cerebrospinal fluid.

Clinical observations indicated a prompt cessation of episcleral capillary bleeding after exposure of those tissues to aqueous humor during intraocular surgery. Based on this observation, both aqueous and vitreous humors were obtained from eyes provided by an eye bank and from human eyes prior to intraocular surgery. Samples of cerebrospinal fluid also were obtained from two patients, one with optic atrophy and another with nutritional amblyopia. A total of 49 specimens were studied. Aqueous humor shortened the average ear lobe puncture bleeding time from 4.74 +/- 0.2 to 1.13 +/- 0.1 minutes. Varying dilutions of aqueous humor, up to a dilution of 1:16, shortened prothrombin and partial thromboplastin times when compared with normal control plasma without aqueous. Vitreous humor shortened partial thromboplastin time but had no effect on prothrombin time. The effect of cerebrospinal fluid on prothrombin and partial thromboplastin times was similar to the aqueous, but to a lesser degree.

Aqueous Humor↗
PubMed1983

Epithelial characteristics of the endothelium in Chandler's syndrome.

The cells lining the posterior surface of a corneal button obtained from a patient with Chandler's syndrome were examined by transmission and scanning electron microscopy, and by keratin staining. The ultrastructural appearance with intracytoplasmic 8 nm filaments, desmosomes, microvillous projections, and positive keratin staining suggests that these may be epithelial cells. Clinical specular microscopy of this cornea prior to transplantation revealed characteristic changes that were seen to be related to the density of microvillous projections on the cell membrane.

Aged↗
PubMed1983

Surgical management of cataract associated with chronic uveitis.

Eight eyes in five patients with cataracts associated with chronic uveitis were operated upon with instrumentation designed for vitreous surgery. A clear visual axis with improvement in visual acuity was achieved in all cases. There were no major operative complications. Vitrectomy instrumentation provides improvements over conventional techniques in the management of these difficult surgical cases.

Adult↗
PubMed1983

Intraocular lenses: experience at The Wilmer Institute.

Nine hundred and thirty-eight consecutive primary intraocular lens (IOL) implant cases performed at The Wilmer Institute during the past six years by two surgeons were reviewed. Progressive corneal endothelial cell loss and an increased rate of late-onset corneal oedema were detected in the group with the Morcher (European) four-loop iris-clip Binkhorst IOLs. A higher rate of clinically-significant cystoid macular oedema developed in eyes with the American-manufactured four-loop Binkhorst lens, presumably from chronic iritis caused by contaminants on the IOLs. Our short-term results with the American-manufactured Shearing-type IOLs implanted at the time of extracapsular cataract extraction are encouraging, with 96% of cases achieving 20/40 vision or better, excluding those with known macular degeneration or amblyopia. Analysis of data submitted to the United States Food and Drug Administration (FDA) indicates that most of the four classes of intraocular lenses (anterior chamber, pupillary-supported, iridocapsular, and posterior chamber) are safe and effective at one-year follow-up. During the past three years there has been a gradual shift of preference in the type of IOLs being implanted--away from pupillary-supported and iridocapsular IOLs and, in part, from anterior chamber IOLs, to posterior chamber IOLs. A continued conservative approach to IOL implantation is recommended.

Aged↗
PubMed1982

Presumed juvenile xanthogranuloma of the iris and ciliary body in an adult.

Juvenile xanthogranuloma (JXG) of the iris is extremely rare in adults. A case of presumed JXG occurred in a 26-year-old woman who was seen initially with bilateral iris lesions and spontaneous hyphema in one eye. Diagnosis was based on the clinical picture and the finding of typical histiocytes obtained by paracentesis and examined by a polymer filtration (Millipore) cytopathologic techniques. Treatment with steroids (given orally and topically to the eye) resulted in a substantial decrease in the size of the iris lesion of the left eye. She has received no medications for 18 months and has shown no signs of progression or other complications 24 months after the initial diagnosis.

Acetates↗
PubMed1982

Traumatic wound dehiscence following penetrating keratoplasty.

Four young male patients with keratoconus had traumatic dehiscence of the surgical wound after penetrating keratoplasty. Two were rendered aphakic by the trauma, and in one patient the lens was dislocated posteriorly. In each case the dehiscence was repaired by resuturing the original corneal graft. Despite marked corneal oedema in the immediate postoperative period all four grafts deturgesced and subsequently cleared. The follow-up has been a minimum of 23 months. We recommend therefore primary resuturing of traumatic wound dehiscence after keratoplasty, anterior vitrectomy if the lens dislodged, and prophylactic antibiotics postoperatively. The clearing of the initially oedematous grafts in each case illustrates the resilience of the corneal endothelium.

Adult↗
PubMed1982

Intraocular lenses. Experience at the Wilmer Institute.

A series of 614 primary intraocular lens (IOL) implantations performed at the Wilmer Institute during the past six years by two surgeons were reviewed. Progressive corneal endothelial cell loss and an increased rate of late-onset corneal edema were detected in the group with the Morcher (European) four-loop iris-clip Binkhorst IOLs. A higher rate of clinically significant cystoid macular edema (CME) developed in eyes with the American-manufactured four-loop Binkhorst lens, presumably from chronic iritis caused by contaminants on the IOLs. Our short-term results with the American-manufactured Shearing-type IOLs implanted at the time of extracapsular cataract extraction are encouraging, with 99% of cases achieving 20/40 vision or better, excluding those with known macular degeneration of amblyopia. A continued conservative approach to IOL implantation is recommended.

Aged↗
PubMed1982

Use of the Honan intraocular pressure reducer at The Wilmer Institute.

Our technique for the preparation of the patient for cataract surgery is discussed, with description of our use of the Honan intraocular pressure reducer (HIPR). Results of preoperative use of the HIPR in a prospective study of 21 patients and our retrospective experience with over 1,000 patients undergoing cataract surgery (with or without lens implantation) are discussed. The HIPR appears to be a safe and effective means of reducing intraocular pressure preoperatively when used with due care.

Cataract Extraction↗
PubMed1982

Corneal perforations. Changing methods of treatment, 1960--1980.

One hundred four nontraumatic corneal perforations or descemetoceles in patients admitted to the Wilmer Institute from 1960 to 1980 were studied retrospectively, with follow-up data obtained from records or from referral physicians for 87 of these perforations. Forty-nine percent of the cases were caused by bacterial corneal ulcers, 13% by exposure, 12% by chemical burns, 6% by fungal keratitis, 5% by herpes simplex keratitis, and 15% were undiagnosed. Since the start of tissue adhesive use at the Wilmer Institute in 1974, there has been an apparent trend towards a lower enucleation rate (6%) in corneal perforations treated with tissue adhesive as compared to 19% in perforations treated by other therapies, although the cases may not be entirely comparable. An improved visual result of 20/200 or better was achieved in 29% of patients treated with tissue adhesive as compared to 19% with other treatment.

Adolescent↗
PubMed1982

Corneal epithelial regeneration and adhesion following acid burns in the rhesus monkey.

For study of corneal adhesion after chemical injury, sulfuric acid was used to burn the central and peripheral corneal epithelium in rhesus monkeys. The adhesion properties of the regenerating epithelium were sequentially followed by clinical assessment and by serial corneal biopsy specimens examined by transmission electron microscopy. The peripheral burns healed uneventfully, but the central corneal burns resulted in persistently loose adhesion for more than 8 weeks. The pathogenesis of the defective epithelial adhesion appeared to initially the persistence of the original basement membrane that could not be utilized by regenerating epithelium. Later, poor adhesion was related to the slow rate of basement membrane regeneration and also to fragmentation of the Bowman's layer substrate and to mild stromal edema.

Animals↗
PubMed1981

Comparative studies of corneal surface injury in the monkey and rabbit.

This animal study of corneal surface injury using acid, alkali n-heptanol, iodine, keratectomy, or scraping, despite morphologic differences from the human, simulated the human response to these forms of trauma. The rabbit and monkey thus remain useful models for the study of the effects of chemical and physical injury on the corneal surface. Although abnormalities in the basement membrane complex seem to play an important role in corneal epithelial adhesion problems, the presence of a poor substratum on which adhesion complexes must in turn rely for their stromal attachment is also an important factor.

Alcohols↗
PubMed1981

Extended-wear contact lenses for myopic correction.

The long-term effects of an extended-wear contact lens (perfilcon A [Permalens]) for myopia were evaluated in 106 patients who had successfully worn the lens for four to eight years (median, 4.94 years). Visual acuity was 6/12 (20/40) or better in 95% of the 207 eyes fitted. Corneal neovascularization, when encountered (8.7%), was mild and did not reduce visual acuity. There were no cases of infectious corneal ulcer or scarring or of permanent visual loss from use of the lens. In selected patients, use of extended-wear lenses seems to be a reasonable form of optical correction of myopia, and they deserve further study. The use of these lenses is discussed as an alternative to the experimental procedure of radial keratotomy.

Adolescent↗
PubMed1981

Extended wear contact lenses for aphakia.

The current modality for correcting unilateral aphakia is by the use of daily wear hard and soft contact lenses and by the use of intraocular lens implants. The use of the Cooper Permalens soft contact lens as an extended wear lens for correction of aphakia was investigated in 177 eyes. The relative merits of the extended wear lens are discussed with emphasis on fit, visual function, and contact lens-related problems.

Aphakia, Postcataract↗
PubMed1981

Choroidal ischemia after extracapsular cataract extraction by phacoemulsification.

Three patients developed apparent choroidal ischemia after phacoemulsification. The outer half of the posterior retina appeared white after operation, with confluent lesions in the posterior pole and splotchy white areas in the midperiphery. The separate lesions appeared similar in pattern to the lobular division of the choriocapillaris, and the retinal vessels were not involved. The white lesions resolved in two to three weeks, leaving alterations in the pigment epithelium. Vision was transiently reduced in each eye but returned to a nearly normal level in two of three affected eyes, although paracentral scotomas persisted. In each case of phacoemulsification, the posterior lens capsule was either damaged or was removed. In all three cases, an investigational type of irrigating solution (BSS Plus) containing balanced salt, glutathione, and other constituents was used. Controlled ocular compression was performed before operation using a pneumatic device in two cases. However, the cause of retinal and choroidal damage now described was probably excessively elevated intraocular pressure during the operation.

Adult↗