Lans lecture. Lamellar refractive surgery: where have we been and where are we going?

In summary, the greatest challenge for lamellar refractive surgery is in the treatment of myopia. There are and always will be patients who are satisfied with a partial correction of myopia. Many of these patients can be served quite adequately by currently available refractive techniques, but a technique in which level of accuracy is adequate for the treatment of myopia in general is not yet available. Lamellar refractive surgery--where have we been and where are we going? We have seen the evolution of the epikeratoplasty procedure for almost a decade and continue to see procedural changes which may increase the accuracy and stability of the procedure, such as alternative modalities for tissue preservation and alternative methods for surgical attachment. It remains potentially useful in several areas of refractive surgery, but its inaccuracy in the treatment of myopia remains a significant problem. Will the epithelial healing problems and postoperative care be too cumbersome for the general ophthalmologist? Will the excimer laser fill the needs of myopic refractive surgery? Personally, I do not feel that any biological lens, be it a cornea which has had incisions as with radial keratotomy, or a cornea which is remolded in one way or another as with the excimer laser, will produce predictable refractive results to the extent that is required to satisfy the general needs of the myopic population. Hydrogel keratophakia is in its infancy, but it holds the potential of being a far more accurate procedure because of the ability to interchange lenses to further refine the refractive result. Refractive surgery will in the next decade achieve a level of sophistication far greater than what we have seen to date. Lans could not have dreamed of the remarkable evolution in refractive surgical innovation in the past century. It is hoped that we will not have to wait that long to create a readily available solution to the problem of refractive surgery for myopia.     

Mathematically directed single-cut osteotomy for correction of tibial malunion

In 1986 and 1987, four patients with tibial malunion involving both angular and torsional misalignment underwent surgical correction by a single-cut technique based on a mathematical model of long bone deformity. The technique involved a single surgical cut, followed by rotation of the two fragments along the osteotomy plane. The orientation of the osteotomy is based on a computer-assisted design. The deformity is measured on radiographs, computed tomography, and clinical exam and is then plotted on graphs to find the osteotomy orientation. The deformity involved varus and extension in four cases, internal rotation in 2, and external rotation in two. The deformities ranged from 9 to 26 degrees. The cutting angle of the osteotomy ranged from 50 to 66 degrees as measured from the transverse plane. Actual lengthening of 1 cm and functional lengthening over 1.5 cm was obtained without the use of bone graft. As no wedge of bone was removed, all corrected bones were easily suited to rigid internal fixation across the cut surface. In all cases, the desired correction was obtained within measurable error, and union was obtained with minimal immobilization. There were no soft tissue or joint contractures, and no neurovascular complications. In one patient, who had had four prior surgical procedures on the involved limb, an infection developed 6 weeks postoperatively that required debridement and delayed primary closure. As the technique involves only one cut, no wedge of bone is removed, no shortening occurs, and the osteotomy is highly suitable for rigid internal fixation. The described technique is the first to integrate in a precise way the correction of torsion with the correction of angular deformity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Angiolymphoid hyperplasia with eosinophilia of the orbit associated with obstructive airway disease

Two patients with angiolymphoid hyperplasia with eosinophilia isolated to the orbit had eyelid swelling, a superior orbital mass, and histories of intermittent obstructive airway disease. One patient later developed a transient peripheral blood eosinophilia as high as 36%. One lesion recurred 38 months postoperatively and responded to systemic corticosteroid therapy.     

Choreoacanthocytosis in a Chinese patient--a case report

A 50-year old Chinese woman with the rare neurological disorder of Choreoacanthocytosis is described. Her illness is characterised by seizures, buccolingual dyskinesia, choreiform movements, arreflexia and mild sensorimotor polyneuropathy. Acanthocytes were present in her peripheral blood in large numbers but the serum lipid profile was normal. Her features are consistent with those so far described in Caucasian and Japanese patients. The disease differs from Huntington's chorea in that there are acanthocytes, peripheral neuropathy, and metal function remains relatively intact.     

Lithium and haloperidol differentially alter the dynorphin A (1-8) and enkephalin levels in the neurointermediate lobe of rat pituitary

Repeated administration of the antimanic drug lithium (4 mEq/kg/day for 2, 4 or 6 days, i.p.) to rats produced a progressive decline and eventual depletion of dynorphin-A (1-8) (DYN) concentration whereas Met5-enkephalin (ENK) was only marginally decreased in the neurointermediate lobe of the pituitary (NIL). Administration of a neuroleptic haloperidol neither affected ENK and DYN levels nor influenced lithium-induced changes. The study reveals that lithium produces a preferential perturbation in the dynorphin system relative to the enkephalin system. These results taken together with other evidence, indicate that dynorphin is possibly coreleased with vasopressin following lithium administration and provide a pharmacological support to the previously described colocalization and corelease of these endogenous peptides in the NIL.     

Peripheral pulmonary artery aneurysm in a patient with limited respiratory reserve: controlled resection using cardiopulmonary bypass

Pulmonary artery aneurysms are rare lesions for which operative management is not frequently undertaken. When operation is indicated, central lesions involving the pulmonary trunk, right main pulmonary artery, or left main pulmonary artery are repaired using cardiopulmonary bypass. Peripheral aneurysms in segmental intrapulmonary arteries have been managed most frequently by lobectomy, but occasionally by aneurysmectomy and pulmonary arterial repair. We used cardiopulmonary bypass for peripheral pulmonary aneurysmectomy in a patient with limited respiratory reserve because he had undergone prior contralateral bilobectomy; this allowed controlled resection while preserving a maximal amount of pulmonary parenchyma.