Ipsilateral transient amaurosis, mydriasis and light reflex absence after subconjunctival local anesthesia with mepivacaine in three patients with refractory glaucoma - a case report.

BACKGROUND: The subconjunctival anesthesia with local anesthetics is considered as a low-risk procedure allowing ocular surgery without serious complications typical for retro- or parabulbar anesthesia, especially in patients with preexisting Optic Nerve damage. We report development of ipsilateral transient amaurosis accompanied with mydriasis and both, direct and consensual light response absence. CASE PRESENTATION: Three patients with advanced refractory glaucoma undergoing laser cyclophotocoagulation (CPC) for intraocular pressure lowering experienced these adverse effects just few minutes after subconjunctival injection of mepivacaine 2% solution (Scandicaine® 2%, without vasoconstrictor supplementation). The vision was completely recovered to usual values in up to 20 h after mepivacaine application. Extensive ophthalmological examination, including cranial magnetic resonance imaging (MRI), revealed no further ocular abnormalities, especially no vascular constriction or thrombotic signs as well as no retinal detachment. The oculomotor function remained intact. The blockade of ipsilateral ciliary ganglion parasympathetic fibers by mepivacaine may be the responsible mechanism. Systemic pathways as drug-drug interactions seem to be unlikely involved. Importantly, all three patients tolerated the same procedure previously or at a later date without any complication. Overall, our thoroughly elaborated risk management could not determine the causative factor explaining the observed ocular complications just in the current occasion and not at other time points. CONCLUSIONS: Doctors should be aware and patients should be informed about such rare complications after subconjunctival local anesthetics administration. Adequate risk management should insure patients' safety.

[Allergic reaction after intravenous application of vitamin B12]. / Allergische Reaktion nach i.v. Gabe von Vitamin B12.

Allergic reactions of parenteral vitamin B12 (cobalamin) for therapy of pernicious anaemia are very rare, but repeatedly described in the literature. In case of allergic reactions oral instead of intravenous substitution of vitamin B12 is tolerated. Very high dosages of vitamin B12 (1,000-2,000 microg per day) are necessary due to the underlying vitamin B12 malabsorption.

[Protective use of calcium in case of osteoporosis versus calcium oxalate stones]. / Calcium gegen Osteoporose trotz Calciumoxalat-Nierensteinen?

In patients with calcium-containing kidney stones calcium supplements are officially contraindicated. Recent studies showed a protective effect by calcium-supplementation when taken with meals, analogous to the decreased risk of kidney stones by dietary calcium due to binding of oxalate. However, because of the poor compliance, costs and the official contraindication for calcium supplements in patients with kidney stones, dietary calcium intake should be preferred whenever feasible.