Gas-permeable scleral contact lens therapy in ocular surface disease

PURPOSE

To describe the therapeutic benefits of nonfenestrated gas-permeable scleral contact lenses in the management of patients with ocular surface disease.

METHODS

The charts of 49 consecutive patients (76 eyes) with ocular surface disease whose management included the use of gas-permeable scleral contact lenses were reviewed. We also developed a questionnaire to assess the impact of lens wear on subjective aspects of activities of daily living.

RESULTS

The mean age of the 49 patients was 44.6 years (range, 3 to 87 years); 31 patients were female and 18 were male. The most common indication for fitting of the lenses was Stevens-Johnson syndrome (54 [71%] of the 76 eyes). Other indications included ocular cicatricial pemphigoid, exposure keratitis, toxic epidermal necrolysis, postherpetic keratitis, congenital deficiency of meibomian glands, superior limbal keratoconjunctivitis, Sjögren syndrome, and inflammatory corneal degeneration. The mean follow-up was 33.6 months (range, 2 to 144 months). Improvement in best-corrected visual acuity (defined as a gain of 2 or more Snellen lines) was observed in 40 (53%) of the eyes. In eight (53%) of the 15 eyes with active corneal epithelial defects at the time of lens fitting, the defects healed, whereas in the remaining seven eyes the corneal epithelial defects remained unchanged. Forty-five (92%) of the 49 patients reported improvement in their quality of life as a result of reduction of photophobia and discomfort. The mean wearing time of the gas-permeable scleral contact lenses was 13.7 hours per day (range, 4 to 18 hours). Many patients had preparatory surgical procedures before lens fitting (for example, punctal occlusion or mucous membrane grafting), and some had visual rehabilitation surgical procedures (for example, keratoplasty and/or cataract surgery) after lens fitting.

CONCLUSIONS

Gas-permeable scleral contact lens wear provides an additional effective strategy in the surface management and visual rehabilitation of patients with severe ocular surface disease.

31P-NMR evaluation of postischemia renal ATP and pH levels after ATP-MgCl2 treatment in rabbits

Phosphorus-31 (31P) nuclear magnetic resonance (NMR) spectroscopy was used to measure adenosine triphosphate (ATP) concentration and pH in vivo in rabbits subjected to a 40-minute period of unilateral renal ischemia to determine the effect of infusing ATP-magnesium chloride (MgCl2, 100 mumol/kg) versus saline at the initiation of reperfusion. Data were compared initially by analysis of variance and then analyzed further using a general linear model with covariate adjustment. ATP-MgCl2-treated animals did not have higher ATP levels during recovery but did have significantly higher renal blood flow (p less than 0.05), a significantly decreased rate of recovery from acidosis (p less than 0.05), and significantly higher urinary output (p less than 0.01) than saline-treated animals during the recovery period. Therefore, treatment with ATP-MgCl2 improves postischemic functional parameters in this model of moderate injury without functioning as a direct source of ATP or its precursors. These data add support to the emerging concept that intracellular acidosis protects cells from reperfusion injury.

[Endoscopic sclerosis for hemorrhage caused by peptic ulcer: a real advance]

The new methods of endoscopic hemostasis for bleeding gastric or duodenal ulcers are discussed. These techniques are increasingly important in patients with high risk for surgery. Due to its low cost, technical simplicity and a success rate similar to the other methods, endoscopic sclerosis is probably the first choice therapy for these conditions.

[Kwashiorkor in an adult with alcoholic hepatic cirrhosis]

Multifactorial malnutrition is common in alcoholic cirrhosis. We report a case dominated by Kwashiorkor due to malabsorption related to infestation with Giardia Lamblia. Malnutrition deserves a complete investigation in order to detect treatable causes.

Corneal stromal wound healing in rabbits after 193-nm excimer laser surface ablation

An argon fluoride excimer laser (193 nm) with a moving slit delivery system was used to perform anterior myopic keratomileusis in both eyes of 24 New Zealand white rabbits. Rabbits were killed immediately after ablation and at intervals up to 100 days. By slit-lamp microscopy, four rabbits at day 100 exhibited four clear corneas and four corneas had central, spotty, subepithelial haze. Light and electron microscopy documented corneal healing. In the early stages a transient acellular zone in the anterior stroma appeared over a period of three weeks, followed by an increased number of fibrocytes. In the corneas with opacification, focal areas of 20-microns-thick subepithelial scarring were present. An unexpected finding was transient damage to posterior stromal keratocytes and endothelial cells. The endothelium produced a layer of granular material that migrated anteriorly across Descemet's membrane. Immunochemistry at day 6 showed a marked staining for collagen IV, proteoglycans, fibronectin, and laminin.

Hypertrophic burn scars: analysis of variables

A major problem in patients surviving thermal injury is the development of hypertrophic burn scars. The current study was performed to determine the factors associated with an increased risk of the development of hypertrophic burn scars. Fifty-nine children (mean age, 3 years; mean TBSA, 14%) and 41 adults (mean age, 37; mean TBSA, 21%) followed from 9 to 18 months formed the study group. The location as well as time required for the burns to heal were recorded in addition to the age and race of the patients. Sixty-three (26%) of the 245 burn areas, in these 100 patients, became hypertrophic. No correlation between patient age and the development of wound problems was found. Blacks had more wound problems than others, if the burn wound took longer than 10 to 14 days to heal. The most important indicator of whether wound problems would occur, in our series, was the time required for the burn to heal. If the burn wound healed between 14 and 21 days then one third of the anatomic sites became hypertrophic; if the burn wound healed after 21 days then 78% of the burn sites developed hypertrophic scars. Based upon these results we have developed a selective, individualized protocol for the use of prophylactic pressure therapy in patients with spontaneously healing burn wounds.

Intravenous anaesthesia by infusion. A technique using alphaxolone/alphadolone (althesin)

Two hundred and seventy-three patients were anaesthetised using aphaxolone/alphadolone as a sole anaesthetic agent, administered in either a 10% solution or in increments of neat drug. Analgesics were given where necessary. This technique was instituted to provide a method of anaesthesia that avoided pollution of the atmosphere, with its possible harmful effects. As experience was gained, better results were obtained. Overall, 86% of the anaesthetics administered were without problems, 12% presented some difficulty, usually minor movement of the patient, and in 2% this technique was abandoned.

Pancreatic pseudocysts in children: 4 cases from Uganda

Four cases of pancreatic pseudocyst in African children are described. There is some evidence that they followed pancreatitis of unknown aetiology. None had a history of trauma. Three were treated by cystogastrostomy, and the fourth by excision of the cyst.

Experimental augmentation of cerebral blood flow by intermittent aortic occlusion

✓ Intermittent occlusion of the descending aorta just below the origin of the brachiocephalic vessels by a preformed balloon passed via the femoral artery is capable of significantly increasing the pressure and flow in the common carotid artery. Regional cerebral blood flow determination by the krypton-85 washout technique measured maximum increases of over 40% of the controls, which could easily be achieved and maintained. This technique apparently takes advantage of the finite delay in autoregulatory response to the increased arterial pressure before the onset of maximal autoregulation. Dogs were “pumped” in this way for up to 18 hours and survived in good health. Principal problems with this technique were the development of cerebral edema in the presence of diffuse established cerebral anoxia, and a shock-like cardiovascular response if the intermittent aortic occlusion was discontinued too abruptly. The clinical application of this technique to cerebral ischemia secondary to postoperative vasospasm may not require the extremes of hyperperfusion used in these experiments.