Amiodarone-associated Optic Neuropathy-A Clinical Criteria-based Diagnosis?

Amiodarone-associated optic neuropathy (AAON) is a controversial diagnosis with possible impact on vital cardiac therapy decisions. This retrospective case series aims for application of distinguishing features of AAON versus non-arteritic ischaemic optic neuropathy (NAION): Bilaterality, mode of onset, degree of optic nerve dysfunction, structure of uninvolved disc (unilateral cases), and systemic toxic effects. Applying these criteria to patients with disc swelling under amiodarone, the authors identified four unilateral disc swellings, one with NAION-typical features only and three with one or more NAION-atypical features. All three sequential and six bilateral cases showed one or more NAION-atypical features. The 12 cases highlight the persisting diagnostic dilemma arising from diversity of presentation, lack of plausible pathomechanism, and controversial existence of the entity itself.

Optic nerve sheath diameter in normal-tension glaucoma patients.

BACKGROUND: To report on the optic nerve sheath diameter (ONSD) in patients with normal-tension glaucoma (NTG) compared with controls without known optic nerve (ON) or intracranial disease. METHODS: In 18 patients with NTG (mean age 64.9 ± 8.9 years; 7 women and 11 men), CT of the orbit was performed. 17 age- and gender-matched patients without ON or intracranial disease, who underwent CT of the orbits for non-ophthalmological reasons, served as controls. The widest intraorbital ONSD in axial sections was measured using a standardised technique. STUDY DESIGN: unmasked. Statistical analysis was performed using an independent two-tailed t Test and the non-parametric Spearman correlation test. RESULTS: ONSD was significantly (p<0.001) increased in NTG patients (right side: mean 7.9 ± 0.9 mm SD; left: 8.0 ± 1.1 mm) compared with controls (right: 6.3 ± 0.5 mm; left: 6.1 ± 0.6 mm). Neither the NTG nor the control group had a significant difference in ONSD between males and females or between right and left sides. CONCLUSIONS: An increased ONSD is generally associated with increased intracranial pressure; however, ONSDs in a group of NTG patients also were significantly increased compared with controls. ON sheath compartmentation and thinning of the ON sheath are two possible explanations for an increase in the ONSD in patients with NTG.

Cerebrospinal fluid dynamics between the basal cisterns and the subarachnoid space of the optic nerve in patients with papilloedema.

AIMS: To determine cerebrospinal fluid (CSF) dynamics between intracranial CSF spaces and CSF in the subarachnoid space (SAS) of optic nerves (ONs) in 10 patients with papilloedema. METHODS: Prospective assessment of 10 patients with papilloedema and two control subjects using CT cisternography and analysis of CSF for the presence of lipocalin-like prostaglandin D synthase (betatrace protein). RESULTS: CT cisternography showed a progressively reduced influx of contrast-loaded CSF from intracranial CSF spaces into the SAS. The lowest concentration of contrast-loaded CSF was found in the region of the ON immediately behind the globe, where the ON sheath was widened (possibly by unfolding) in all patients compared with normal subjects. The concentration of lipocalin-like prostaglandin D synthase differed between the spinal CSF and the CSF in the SAS, with a markedly higher concentration in the SAS. CONCLUSION: The results of this study suggest that CSF turnover in the SAS of the ON is reduced in patients with papilloedema from various causes and that the composition of CSF differs between spinal CSF and that surrounding the ON.