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Biomedical subjects

W J Stark

Publications and source records attributed to W J Stark.

At least 217 records · Page 12Linked to original sources
PubMed1980

Management of posteriorly dislocated intraocular lenses.

Posterior dislocation of an intraocular lens (IOL) into the vitreous cavity can be a serious problem, and probably will become more frequent because of increasing popularity of posterior-chamber lenses. We describe techniques for managing a posteriorly dislocated lens that cannot be repositioned in its proper location by medical means. Vitrectomy instrumentation and techniques through a pars plana approach provide optimal visualization during manipulation of the intraocular lens, minimize vitreoretinal traction and permit one to reposition the IOL in its proper location relative to the iris or to position it in the anterior chamber in preparation for removal. A modification of the McCannel iris-fixation suture technique is also presented.

Lens Subluxation↗
PubMed1979

Extended-wear contact lenses and intraocular lenses for aphakic correction.

We evaluated extended-wear soft contact lens use in 128 aphakic eyes of 113 patients, 44 of whom had been unable to wear conventional contact lenses; 116 eyes (91%) have been successfully fitted and have worn the extended-wear lenses without significant complication. Eleven patients were unable to wear the lens or had to be discontinued for transient lens-related problems. In 103 eyes successfully fitted the lens is removed for cleaning less often than monthly. Ninety six of the 116 eyes fitted have visual acuity as good as, or better than, with aphakic correcting spectacles. The results obtained with the extended-wear soft contact lens are similar to those obtained with intraocular lenses, except for the recent high incidence of inflammation seen after intraocular lens insertion when using ethylene-oxide-sterilized lenses.

Adolescent↗
PubMed1979

Management of congenital cataracts.

The management of congenital cataracts at the Wilmer Institute is presented, with emphasis on the need for careful preoperative assessment. The indications and techniques for surgery in uncomplicated cataracts are discussed, and the advantages of using vitrectomy instruments in complicated congenital cataracts, such as those associated with persistent hyperplastic primary vitreous, are described.

Cataract↗
PubMed1979

Nocardia asteroides keratitis.

Nocardia asteroides has been reported as the cause of keratitis in only 7 cases and of other ocular disease in another 12 cases. We report a case of N. asteroides keratitis that presented 3 weeks after rural trauma and progressed despite trials of appropriate antibiotics. Seven weeks after the origianl injury a successful conjunctival flap was placed over the cornea. The morphology and the sensitivity testing of N. asteroides to antibiotics appears necessary before reliable information can be obtained for clinical use. Moreover, our case did not show the relatively benign course of other reported cases of nocardia keratitis.

Adolescent↗
PubMed1979

Vitrectomy methods in anterior segment surgery.

We have used vitrectomy instrumentation and techniques to treat a variety of conditions affecting the anterior segment, including: 1) an occluded or inadequate pupillary space, 2) complications of vitreous in the anterior chamber, 3) epithelial ingrowth, 4) complicated lens surgery, and 5) total hyphema. The vitrectomy methods provided controlled excision of intraocular tissues under optimum visualization using a closed-eye system with normal intraocular pressure and the ability to use techniques such as intraocular diathermy. Our experience has been favorable in this series of 117 cases. Of these, 104 cases (89%) were anatomically successful, 70 eyes (60%) had a significant postoperative improvement in vision. The detailed results of vitrectomy surgery for anterior segment disorders are presented for each indication.

Adolescent↗
PubMed1979

Tissue adhesives: new perspectives in corneal perforations.

In corneal perforations associated with extensive progressive corneal disease, a technique using tissue adhesive closure of the perforation site and reformation of the anterior chamber before penetrating keratoplasty or conjunctival flap mobilization has been described. Over the past year, six eyes have been successfully treated in this manner. This method allows reformation of the eye under local anesthesia as an emergency procedure without incarceration or injury of the intraocular contents and without pain to the patient. The definitive surgical procedure can then be performed safely under retrobulbar anesthesia.

Adult↗
PubMed1978

Histocompatibility (HLA) antigens and keratoplasty.

In 84 cases of keratoplasty, all patients had densely vascularized corneas and a history of prior exposure to HLA antigens by pregnancy, blood transfusion, or previous transplantation. Donors were selected on the basis of a negative crossmatch to avoid donor antigens to which the recipient was preimmunized. The overall rate of graft failure from rejection was 15%. A retrospective analysis of donor-recipient HLA matching in 103 high-risk cases showed no consistent correlation between the number of antigens shared and graft outcome. These findings indicated negative cross-match to be important in donor selection for keratoplasty in high-risk cases.

Adolescent↗
PubMed1978

Surgical management of epithelial ingrowth.

In ten consecutive cases of epithelial ingrowth operated on during the past 33 months, therapy included photocoagulation of the iris followed by excision of involved iris tissue and vitreous gel by means of instruments designed for vitreous surgery. Epithelium remaining on the posterior surface of the cornea, ciliary body, and in the anterior chamber was destroyed by controlled transcorneal and transscleral cryotherapy. An intraocular air bubble was used to provide an insulating effect and a more effective, controllable freeze. All patients except two had improved vision postoperatively, and four of the ten patients had postoperative visual acuity of 6/12 (20/40) or better.

Adult↗
PubMed1978

Donor corneal endothelium: slit-lamp examination of buttons in storage medium.

The integrity of the corneal endothelium is vital to the maintenance of a clear graft. The slit-lamp examination of the cornea from the endothelial surface, as described, allows the exclusion from transplantation of buttons with obvious endothelial trauma or disease. The use of this method at the Wilmer Institute during the last four years has been part of the preoperative assessment of all corneal donor buttons and has helped to reduce the rate of early graft failure.

Cornea↗
PubMed1977

A two-year trial of intraocular lenses at the Wilmer Institute.

Using the Binkhorst four-loop intraocular lens, we began a trial of intraocular lens implantation in 1975. We compared the operative and postoperative complications and the visual results of 100 implant cases during a two-year period to those of 100 age-matched aphakic control cases. Although the additional steps of lens implantation resulted in more operative and postoperative complications in the intraocular lens group, the visual results were good and were the same for both groups at an average follow-up of 12 months. Because the long-term follow-up results of implant cases are unknown, we recommend a conservative approach to selection of patients for intraocular lens implantation.

Aged↗
PubMed1977

Quantitative corneal endothelial evaluation in intraocular lens implantation and cataract surgery.

We analyzed pre- and postoperative corneal endothelial photographs of 33 intraocular lens patients and found an average endothelial cell density loss of 14%. Twenty-six cataract patients, similarly examined, showed a 13% mean endothelial cell loss. In 14 of the intraocular lens patients, a second postoperative evaluation of the central endothelium, at a later date, revealed a trend toward continuing cell loss. Our results indicate fewer endothelial cells were lost after intraocular lens implantation than has been previously reported. This may be accounted for by our considering only patients with normal corneas for lens implantation, and by our constant maintenance of the anterior chamber with an air bubble during lens implant surgery.

Aged↗
PubMed1977

Damage to epithelial basement membrane by thermokeratoplasty.

To determine the effects of thermokeratoplasty (TKP) on the basement membrane complexes of the corneal epithelium, transmission electron microscopy was performed on the corneal buttons of five patients with failed TKP and on two normal corneas and five corneas with keratoconus that were immediately treated by TKP (acute TKP). The consistent findings of thermal dissolution of basement membrane after acute TKP and persistent defects of basement membrane complexes many months after therapeutic thermokeratoplasty were significant. Given the potentially damaging effects of thermokeratoplasty on the epithelial basement membrane, faulty epithelial adhesion should be anticipated after thermokeratoplasty and should be treated aggressively, possibly with careful prophylactic use of bandage hydrophilic contact lenses.

Adult↗
PubMed1977

A non-permanent tonic pupil in rheumatoid arteritis.

A 76-year-old male with a severely deforming rheumatoid arthritis, eosinophilia, polymyositis, and episcleritis developed a transient tonic pupil. The episcleritis, and a muscle biopsy revealing an occlusive arteritis with eosinophilia, suggest that a wide-spread rheumatoid arteritis caused a reversible ischemic insult to the ciliary ganglion and thus created a transient denervation of the pupil.

Aged↗
PubMed1977

Regeneration of corneal epithelial basement membrane following thermal cauterization.

Thermal cauterization of the corneas of nine rhesus monkeys was performed by multiple thermokeratophore applications at temperatures of 90 degrees or 120 degrees C. Significant clinical observations included the resteepening of corneal curvature, delayed epithelial healing, stromal haze or scarring, and peripheral neovascularization. Reestablishment of tight adhesion of the regenerated epithelium to Bowman's layer required approximately 6 weeks. By transmission and scanning electron microscopy, the original basement membrane seemed relatively intact immediately following cauterization but disappeared within 1 week. The regeneration of new basement membrane complexes began at 1 week with the appearance of short discontinuous segments of basement material with hemidesmosomes and similarly required approximately 6 weeks for complete restoration.

Animals↗