Limbal conjunctival autograft in a subacute alkaline corneal burn.

Persistent epithelial defects are a common complication after severe alkaline corneal burns. Chemical damage to the limbal area destroys the stem cells that play a key role in corneal reepithelialization. Limbal conjunctival autograft transplantation has been proposed as a treatment to replace damaged limbal stem cells and promote epithelial healing. We report a case of a persistent epithelial defect after a severe alkaline corneal burn that was successfully treated 6 weeks after the injury with limbal autograft transplantation. Impression cytology provided valuable information for locating the healthy and damaged limbal tissue involved in the transplantation. Two weeks postoperatively the epithelial defect was completely healed, stromal vascularization was regressed, and visual acuity was improved.

Quantitative measurement of wound spreading in radial keratotomy.

BACKGROUND: Many studies of radial keratotomy have been performed, however quantitative laboratory evaluation of the biomechanics of this procedure is still incomplete. Furthermore, most measurements of strain in the past have utilized strip testing, thus destroying the normal physiological structure and water balance of the cornea. METHODS: We report on a membrane inflation method of wound spreading in intact human corneas using the Baribeau Micronscope. RESULTS: We measured a secant elastic modulus of 7.58 x 10(6) N/m2 between 25 and 100 mm Hg. The spreading of radial keratotomy incisions as a function of intraocular pressure showed a maximum spreading of approximately 50 mu at 25 mm Hg at a radius of 3.50 mm from the optical center. A slight increase in spreading was observed in proceeding from a single to four radial incisions. CONCLUSIONS: Quantitative measurement of wound spreading is an important parameter of radial keratotomy and can provide important information regarding opposing theories of the biomechanics of this operation.

Surgical treatment of the parathyroid gland in patients with end-stage renal disease.

During the period from December 1984 to December 1986, ten patients with end-stage renal disease were evaluated with hyperparathyroidism refractory to medical management. Symptoms were bone pain in eight patients and pruritus and constipation in two. Two patients with bone pain also had impaired mentation. Biochemical preoperative assessment revealed calcium levels between 8.7 and 11.2 milligrams per deciliter, with a median of 10.5 milligrams per deciliter. Phosphate levels were normal in all but three patients, and the phosphate-calcium product was greater than 80 in two. Parathyroid hormone levels assessed with the radioimmunoassay method were elevated in all patients, and results of ultrasound of the neck, done in seven patients, revealed hyperplastic glands in six patients and normal glands in one patient. All patients underwent surgical exploration of the neck with removal of four parathyroid glands and immediate autotransplantation. No complications related to the operative procedure occurred. Postoperative calcium levels ranged between 6.5 and 9.5 milligrams per deciliter on the first postoperative day and normalized by the sixth day. Four patients experienced symptomatic hypocalcemia requiring intravenous calcium supplementation for one to six days postoperatively. The mean hospital stay was four days (three to seven days). All patients had histologically confirmed four gland parathyroid hyperplasia. Marked improvement of symptoms was accomplished in all patients after a period of three to 30 days. One patient required revision of the forearm parathyroid transplant after four months. One patient required calcium supplementation taken orally, two patients required 1,25-Dihydroxyvitamin D3 and five required treatment with both. Two patients did not require any further medical treatment, and no patient had recurrent symptoms after a mean follow-up period of eight months. We recommend total parathyroidectomy with autotransplantation in patients with end-stage renal disease as a safe and effective procedure for symptomatic refractory hyperparathyroidism. Symptom relief can be accomplished in the vast majority of patients.