Effect of intraocular lens fixation on acute intraocular pressure rise after neodymium-YAG laser capsulotomy

Neodymium-YAG laser posterior capsulotomy is associated in some cases with an acute rise in the intraocular pressure (IOP), possibly caused by blockage of the trabecular meshwork by debris. To test the hypothesis that the IOP rise is preventable if fixation of the intraocular lens (IOL) in the capsular bag is ensured, we conducted a study comparing IOP changes at 1, 2, 3 and 24 hours after Nd:YAG capsulotomy between eyes with capsular bag-fixated, one haptic in the bag (haptic in/out) and cillary sulcus-fixated IOLs. Analysis of variance for repeated measures showed that after capsulotomy there were significant increases in IOP from baseline (p < 0.05) in both the sulcus-fixated (1, 2 and 3 hours) and haptic in/out groups (2 and 3 hours), while IOPs in the bag-fixated group did not show any significant increase. The increases in IOP in the sulcus-fixated group at 1, 2 and 3 hours after capsulotomy were significantly higher than the IOP changes at the corresponding periods in the other two groups (Kruskal-Wallis test, p < 0.01). The mean maximum IOP rise in the sulcus-fixated group (11.33 +/- 7.85 mmHg) was significantly higher than that in the haptic in/out group (3.89 +/- 7.14 mmHg) and the bag-fixated group (1.10 +/- 2.71 mmHg), while there was no difference between the latter two groups. In 57.5% of the sulcus-fixated group, 5% of the haptic in/out group and none of the eyes of the bag-fixated group the IOP rise was more than 10 mmHg. A significantly larger proportion of sulcus-fixated eyes had anterior chamber cells and capsular debris after capsulotomy (chi 2 test, p < 0.001). In the haptic in/out group significant correlation (-0.56, p = 0.009) between IOP rise at 1 hour and the percentage enclosure of the IOL by the anterior capsule was demonstrated. There was no significant difference in maximum IOP rise between glaucomatous and non-glaucomatous eyes (Mann-Whitney U-test, p = 0.49).

Unconventional pedicle spinal instrumentation. The Bombay experience

STUDY DESIGN

A retrospective study of all patients who underwent spinal fusion between 1986 to 1989 with inexpensive, locally made unconventional pedicle spinal instrumentation systems was undertaken. Implants were made with passivated 316L stainless steel, and a single level of instrumentation cost +f430.

OBJECTIVES

To demonstrate that simple, cheap pedicle instrumentation systems are as effective as the conventionally available expensive systems, provided proper anterior column support is maintained.

METHODS

Ninety out of 102 patients were available for review. Average follow-up was 41 months (range, 22 to 60 months). Implant failures, screw placement, fusion rates, infection, neurologic deficit due to the implant, patient satisfaction, and the benefit of anterior column grafting with the unconventional pedicle spinal instrumentation systems in the long term were evaluated.

RESULTS

Forty-four out of 467 screws failed (9%) in 16 patients, seven of whom were symptomatic. There were no plate failures. On comparing burst fractures with (n = 12) and without (n = 10) anterior column grafting, the latter group had a significant increase in implant failures, loss of sagittal alignment, and the time required to fusion. Overall, fusion occurred within 6.5 months.

CONCLUSIONS

Anterior column reconstruction in anterior column deficient spines will re-create the normal biomechanics and significantly reduce the incidence of implant failures and loss of sagittal alignment with these systems. Pedicle screw failure in itself is not necessarily associated with a bad result. These inexpensive, locally made unconventional systems, with the proper understanding of biomechanics and creation of appropriate load-sharing constructs, are as good as the conventional systems available today.

p-Aminobenzene sulphonyl morpholine, compound 82/208 a new anticonvulsant agent

p-Aminobenzene sulphonyl morpholine, compound 82/208, was evaluated for acute toxicity and anticonvulsant action in mice against tonic seizures induced by supramaximal electroshock and pentylene tetrazole and strychnine induced seizures and for its effect on blood pressure and respiration in cat. Diphenyl hydantoin (DPH) was used as reference standard. Compound 82/208 exhibited anticonvulsant activity against electroshock induced seizures and PTZ induced tonic seizures in mice. The compound had several distinct advantages over DPH in experimental evaluation in mice.

Role of nitric oxide in esophageal peristalsis

In vitro studies have suggested that NO may be a nonadrenergic, noncholinergic inhibitory mediator in the esophageal body. We examined the role of NO in physiological peristalsis in anesthetized opossums by assessing the effect of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) on esophageal contractions induced by swallows, prolonged vagal efferent nerve stimulation, and midesophageal balloon distension. A perfused manometry system measured intraluminal pressures 1 and 5 cm orad to the lower esophagus, and suction electrodes monitored membrane potential changes at the same locations. NO synthase inhibition 1) decreased swallow-induced contraction amplitude in the distal esophagus and, when combined with atropine, abolished these contractions; 2) diminished swallow-induced contraction latencies, predominantly in the distal esophagus, thereby decreasing the latency gradient and increasing the peristaltic velocity; 3) abolished vagal-stimulation-induced, end-of-stimulus "B" contractions and either unmasked or increased the amplitude of intrastimulus "A" contractions; 4) abolished the contractions occurring at the end of balloon distension; and 5) inhibited the membrane hyperpolarization and the subsequent nonadrenergic, noncholinergic depolarization induced by all three stimuli. These data support the hypothesis that NO is a mediator of nonadrenergic, noncholinergic neurotransmission in the opossum esophagus. Furthermore, the data suggest that esophageal peristalsis is mediated by a "blended" activation of cholinergic and nonadrenergic, noncholinergic (via NO) neurons.