Magnesium for Implants: A Review on the Effect of Alloying Elements on Biocompatibility and Properties.

An attempt is made to cover the whole of the topic of biodegradable magnesium (Mg) alloys with a focus on the biocompatibility of the individual alloying elements, as well as shed light on the degradation characteristics, microstructure, and mechanical properties of most binary alloys. Some of the various work processes carried out by researchers to achieve the alloys and their surface modifications have been highlighted. Additionally, a brief look into the literature on magnesium composites as also been included towards the end, to provide a more complete picture of the topic. In most cases, the chronological order of events has not been particularly followed, and instead, this work is concentrated on compiling and presenting an update of the work carried out on the topic of biodegradable magnesium alloys from the recent literature available to us.

[Giant retroperitoneal hydatid cyst]. / Kyste hydatique rétropéritonéal géant.

Hydatidosis is an endemic, widely distributed anthropozoonosis, which involves the liver, lung and other organs [Int J Urol 13 (2006) 76-9]. We reported the case of a large retroperitoneal hydatid cyst, which is a rare situation [Hepatogastroenterology 48 (2001) 1037-9; Int Urol Nephrol 32 (2000) 41-6; J Urol (Paris) 94 (1988) 445-8]. Diagnosis was suspected with blood tests and radiological examinations. A wide incision in the right iliac fossa (such in renal graft) was performed. The cyst wall was excised partially. Before, during and following the operation, the patient was given albendazole tablets (15mg/kg per day) for 3 weeks (1 week before and 2 weeks after the surgery) with blood count and liver enzyme monitorization. Especially in the endemic areas, hydatid cyst should be remembered when evaluating cystic masses in the retroperitoneum. It can be treated successfully with surgery.

Cost considerations of the new fixed combinations for glaucoma medical therapy.

OBJECTIVE: To compare the costs of the new fixed combinations for glaucoma medical therapy. METHODS: The studied drugs were: Cosopt (5-mL bottle), Combigan (5-mL bottle) and Xalacom (2.5-mL bottle). Five bottles of each drug were obtained from pharmacies, and the medications lot numbers were recorded. To calculate the drop volume, 10 drops and 1 mL of each bottle were weighed with a digital precision scale. Drop volume was calculated by the relation between volume and weight. The cost of each bottle of medication was determined from the average retail price in Canada. The prices were obtained in Canadian dollars (dollars). RESULTS: The drops of Cosopt (39.60 +/- 0.45 microL) were considerably larger than the drops of Combigan (33.75 +/- 0.60 microL) and Xalacom (30.87 +/- 0.37 microL). The average number of drops per millilitre varied from 25.25 +/- 0.29 (Cosopt) to 32.40 +/- 0.39 microL (Xalacom). Combigan presented the lowest daily cost (dollars 0.87 +/- 0.02) followed by Xalacom (dollars 1.09 +/- 0.01) and Cosopt (dollars 1.22 +/- 0.01). The average cost by year varied from dollars 316.75 +/- 5.59 (Combigan) to dollars 445.96 +/- 5.16 (Cosopt), with a total difference of dollars 129.21 per year of treatment. CONCLUSIONS: There was a statistically significant difference in average drop size and cost among the three studied drugs. Combigan presented the lowest daily cost followed by Xalacom and Cosopt.

Short-term results of holmium laser sclerostomy in patients with uncontrolled glaucoma.

Holmium laser sclerostomy, an ab externo filtering procedure done with minimal conjunctival dissection, was performed in 55 eyes, most of which had significant risk factors for failure of filtration. The success rate was 71% at 3 months and 74% at 6 months. Major complications included choroidal hemorrhage (in one eye) and cataract (in two). These short-term results are encouraging, particularly for complicated glaucomas.

An association between hypothyroidism and primary open-angle glaucoma.

PURPOSE: To test the hypothesis that there is an association between hypothyroidism and primary open-angle glaucoma. METHODS: The study was conducted in a case-control fashion. Sixty-four patients with primary open-angle glaucoma were evaluated for hypothyroidism by history and by undergoing a thyroid-stimulating hormone immunoradiometric assay. Sixty-four control subjects from the general eye clinic were evaluated in the same manner. Patients found to have elevated thyroid-stimulating hormone immunoradiometric assay were evaluated by an endocrinologist for hypothyroidism. RESULTS: Of the primary open-angle glaucoma group, 23.4% had hypothyroidism. A diagnosis was made previously in 12.5% patients, and 10.9% were newly diagnosed. Of the control subjects, 4.7% had hypothyroidism. A diagnosis had been made previously in 1.6% of the control subjects, and 3.1% were newly diagnosed. The difference between the two groups was found to be statistically significant. CONCLUSION: A statistically significant association between hypothyroidism and primary open-angle glaucoma is demonstrated. There is a large group (10.9%) of patients with primary open-angle glaucoma with undiagnosed hypothyroidism.

Treatment of encapsulated blebs with 30-gauge needling and injection of low-dose 5-fluorouracil.

We describe a simplified needling procedure, performed at the slit-lamp, with injection of low-dose 5-fluorouracil to treat encapsulated filtering blebs. Between August 1989 and December 1990 we treated 17 eyes of 14 patients with this procedure. At 2 months 13 of the eyes had needed only one needling procedure. Risk factors for reencapsulation of the bleb were a history of three or more previous surgical procedures (p less than 0.05) and prolonged preoperative use of topical adrenergic drugs (p less than 0.05). At 1 year all but one eye had an intraocular pressure below 21 mm Hg (median 15 mm Hg). Twelve of the eyes had needed more than one needling procedure. There were no serious complications of the 32 procedures performed. The incidence rate of minor complications (wound leaks, corneal erosion and small hyphemas) was 38%.

Efficacy of twice-daily levobunolol in the treatment of elevated intraocular pressure.

The efficacy of twice-daily treatment with 0.5% levobunolol hydrochloride was compared with that of 0.5% timolol maleate in 27 patients with open-angle glaucoma or ocular hypertension in a double-blind randomized trial. At all follow-up visits the patients in both groups had significantly decreased intraocular pressure (p less than 0.05); there was no significant difference between the groups. Levobunolol produced significant decreases in mean heart rate (p less than 0.05). One patient with an undisclosed history of childhood asthma experienced bronchospasm related to an acute upper respiratory tract infection while receiving levobunolol. Neither drug caused any significant ocular problems. The results show a clear ocular hypotensive effect with twice-daily 0.5% levobunolol.

Timolol: long-term Canadian multicentre study.

This paper reports a 200-week-long study of the efficacy of timolol maleate ophthalmic preparations. At centres across Canada 117 patients were studied according to a rigid protocol. Timolol maleate was shown to be an effective antiglaucomatous drug, maintaining the intraocular pressure below 22 mm Hg throughout the study in 137 (60%) of the 227 eyes. No clinically significant effect on the pulse rate or the mean perfusion pressure was demonstrated, and the medication was well tolerated, causing few side effects or adverse reactions.

Posterior lenticonus.

Two patients with posterior lenticonus; one was unilateral and the other was bilateral. The second patient had bilateral cataract extractions and the lenses were examined histopathologically. Postoperatively she did not have any amblyopia. The purpose of this presentation is to illustrate two points from the clinicopathological findings: The pathogenesis of the anomaly is mainly due to inherited thinning and weakness of the central part of the posterior lens capsule. We suggest that the posterior lenticonus without complicated cataract is not a main cause of profound amblyopia. The amblyopia is dependent on the age at which the cataract develops.

Abnormal blood vessels on the optic disc.

Twenty-five patients with abnormal blood vessels on the optic nerve head were examined both clinically and with fluorescein angiography to determine the diagnostic significance of these abnormal vessels. Six patients had congenital abnormal vessels--prepapillary or optociliary arteries or veins, or vessels associated with congenital anomalies of the disc. Nineteen patients had acquired abnormal vessels that were associated with retinal vein occlusion, chronic glaucoma, chronic papilledema, meningioma or vasculitis. The clinical and fluorescein angiographic features that differentiated these groups are discussed in detail.

Thymoxamine versus pilocarpine in the reversal of phenylephrine-induced mydriasis.

Thymoxamine, a selective alpha-adrenergic blocker, was compared with pilocarpine in 19 patients for its reversal of phenylephrine-induced mydriasis. Both agents constricted the pupil to its original size in less than half an hour, and thymoxamine's half-life was twice that of pilocarpine's. The advantages of thymoxamine miosis, particularly in patients with narrow angles, are discussed.

Variability of static visual threshold responses in patients with elevated IOPs.

We determined the static visual thresholds within 15 degrees of fixation of 36 patients with elevated intraocular pressures but normal visual fields and compared the result with 36 controls matched for age and sex. We found no difference in the mean threshold level between the two groups. We did find a tendency for the patients with elevated IOPs to have greater variability or scatter of their threshold responses close to fixation. We also found the patients had larger cup to disc ratios than the controls.

Effect of thymoxamine and pilocarpine on the depth of the anterior chamber.

Thymoxamine, an alpha-adrenergic receptor blocking agent, was compared with pilocarpine in 11 patients for its effect on the depth of the anterior chamber. In the eyes treated with thymoxamine rapid and sustained miosis occurred without a significant change in the depth of the anterior chamber. On the other hand, the miosis induced by pilocarpine was accompanied by significant shallowing of the anterior chamber.

Rieger's anomaly with congenital glaucoma a case presentation of postnatal anterior segment maturation.

We describe an unusual case of Rieger's anomaly with congenital glaucoma in an infant in whom significant maturation of the anterior segment occurred postnatally. Medical treatment of the glaucoma was successful. The control of the glaucoma coincided with the maturation of the angle, suggesting that the two events could be related.

Iris nevus syndrome.

We present a case of iris-nevus or Cogan-Reese syndrome with its characteristic pathological findings. Although a rare entity, it should be considered in the differential diagnosis of heterochromia associated with elevated intra-ocular pressure. To avoid unnecessary enucleation, it should not be confused with diffuse iris melanoma.

Response to topical epinephrine in chronic open-angle glaucoma.

The epinephrine pressure reduction was determined in 32 patients with elevated intraocular pressure (IOP) and 18 patients with untreated chronic open-angle glaucoma. The prevalence of responders was 53% of those patients with elevated IOP and 56% in those patients with open-angle glaucoma. This lack of difference between the two groups is suggestive of the need for caution before applying epinephrine in clinical practice as a predictive factor of future field loss.

Posterior polymorphous corneal dystrophy and juvenile glaucoma: a case report and brief review of the literature.

A family with posterior polymorphous corneal dystrophy is presented that includes a child with juvenile glaucoma. A review of the literature reveals an increased incidence of juvenile glaucoma associated with this dystrophy. It is of practical importance that the dystrophy be recognized and glaucoma be ruled out as the latter is asymptomatic in the infant.