Orbital Air Embolism After Intravenous Injection.

An asymptomatic air embolism in the right superior ophthalmic vein was discovered incidentally during a cerebral computed tomography, most likely due to a preceding intravenous fluid bolus. This case illustrates the potential risk of air emboli being propagated to the cerebral venous circulation during routine injections and fluid resuscitation.

Sibling Ethambutol Optic Chiasmopathy.

Ethambutol is utilised in the treatment of Mycobacterium avium and Mycobacterium tuberculosis infection. The authors report two siblings who developed the adverse effect of ethambutol-induced optic chiasmopathy, with recovery following cessation of ethambutol. Discussion explores potential genetic predisposition to development of this condition and its resolution. Ethambutol optic neuropathy (EON), Leber's hereditary optic neuropathy (LHON), and other optic neuropathies of mitochondrial origin share a common pathophysiology. Consequently, the authors postulate treatments utilised in LHON, including vitamin B supplementation and idebenone, may have benefit in EON. This article presents concepts for further research, suggesting a potential genetic susceptibility to EON and its treatment.

Glaucoma severity at first presentation to an ophthalmologist and risk factors for late presentation in rural Australia: the S1P study.

CLINICAL RELEVANCE: Well-targeted referrals and timely commencement of treatment are essential to limiting vision loss in glaucoma. Optometrists, primary care providers, and public health policymakers can utilise predictors of late to identify and target at-risk populations. BACKGROUND: This study, which aimed to evaluate glaucoma severity at first presentation to an ophthalmologist in a rural Australian population, is the first of its kind in an Australian population. METHODS: Patient records from a large ophthalmology clinic in Port Macquarie, NSW were retrospectively reviewed using the Fight Glaucoma Blindness registry to identify patients who were first diagnosed with glaucoma at an ophthalmology practice in 2020 or 2021. Associations with glaucoma severity at presentation, measured with visual field index (VFI), were analysed using a beta-regression model. Retinal nerve fibre layer measurements were evaluated as a secondary outcome measure using linear regression. RESULTS: From 3548 new patients seen, 110 cases of glaucoma were diagnosed, 95 of whom met inclusion criteria. These comprised 41.8% primary open-angle glaucoma, 32.7% normal-tension glaucoma, 11.8% secondary open-angle glaucoma, 12.7% primary angle closure glaucoma, and 0.9% secondary angle closure glaucoma. The median VFI at presentation was 94.5%, and 71.9% of patients had a VFI ≥ 90%. However, 6.3% of patients presented with a VFI below 50%. Older age, higher intraocular pressure, and worse visual acuity were significantly associated with severity at presentation. No associations were found for remoteness, sex, family history, or glaucoma type. CONCLUSIONS: Glaucoma appears to be diagnosed relatively early in this population. Severity at presentation was associated with age, intraocular pressure, and visual acuity, but not influenced by the social determinants assessed. These findings underscore the importance of frequent comprehensive eye examinations in older patients. Replication in other Australian populations is recommended as the generalisability of these findings is limited.

Evaluation of arterial grafts prior to coronary bypass in pseudoxanthoma elasticum.

Pseudoxanthoma elasticum is a rare, inherited connective tissue disorder associated with coronary and peripheral arterial disease and accelerated atherosclerosis in medium sized arteries. We describe 110-month symptom-free survival in a patient with pseudoxanthoma elasticum who underwent coronary bypass using the left internal mammary artery at 56 years of age. The vessel was evaluated pre-operatively with angiography to determine suitability, and he has not required further investigation or intervention due to lack of symptoms.

Left ventricular support with the Impella LP 5.0 for cardiogenic shock following cardiac surgery.

We report the first Australian use of the Impella LP 5.0, a minimally invasive, high-output left ventricular assist device. The device was inserted intra-operatively for cardiac failure following coronary artery grafting. Although it facilitated a temporary post-operative recovery, the patient ultimately succumbed due to left ventricular failure more than 30 days after the original procedure. This device has several advantages over existing forms of left ventricular support, and has the potential for widespread use in Australian centres.

Para to ortho repositioning of the arsenical moiety of the angiogenesis inhibitor 4-(N-(S-glutathionylacetyl)amino)phenylarsenoxide results in a markedly increased cellular accumulation and antiproliferative activity.

The synthetic tripeptide arsenical 4-(N-(S-glutathionylacetyl)amino)p-phenylarsenoxide (p-GSAO) is an angiogenesis inhibitor that inactivates mitochondrial adenine nucleotide translocase (ANT) by cross-linking a pair of matrix-facing cysteine residues. This causes an increase in superoxide levels and proliferation arrest of endothelial cells followed by mitochondrial depolarization and apoptosis. p-GSAO induces proliferation arrest in endothelial cells and is a selective inhibitor of endothelial cells compared with tumor cells. An analogue of p-GSAO has been made in which the arsenical moiety is at the ortho instead of the para position on the phenyl ring. o-GSAO, like p-GSAO, bound to ANT in a dithiol-dependent manner but was approximately 8-fold more efficient than p-GSAO at triggering the mitochondria permeability transition in isolated mitochondria. o-GSAO was an approximately 50-fold more potent inhibitor of endothelial and tumor cell proliferation than p-GSAO. The mechanism of this effect was a consequence of approximately 300-fold faster rate of accumulation of o-GSAO in the cells, which is due, at least in part, to impaired export by the multidrug resistance-associated protein 1. Administration of o-GSAO to tumor-bearing mice delayed tumor growth by inhibiting tumor angiogenesis but there were side effects not observed with p-GSAO administration.