Mark Paine

Axonal loss and myelin in early ON loss in postacute optic neuritis

To investigate the relation between retinal nerve fiber layer (RNFL) thickness and latency and amplitude of multifocal visual‐evoked potentials (mfVEPs) in the postacute stage of optic neuritis in patients with early or possible multiple sclerosis.

Steroid management in giant cell arteritis

AIM Ocular involvement in giant cell arteritis (GCA) is an ophthalmic emergency which, if untreated, can progress to permanent blindness. There is little evidence in the literature to support current protocols for the acute treatment of GCA with steroids. The authors sought to review the effects of intravenous and oral steroids in GCA. METHODS This retrospective study reviewed the records of 100 consecutive patients with biopsy proved giant cell arteritis. 73 patients with visual loss who were treated at the Royal Victorian Eye and Ear Hospital (RVEEH) and St Vincents Hospital were included in the final series. The authors studied the management of the patients in the first week after presentation, analysing types of treatment, dose, effect on visual acuity, and complications. RESULTS All the patients except one had visual loss due to anterior ischaemic optic neuropathy (AION). 17 patients (23%) had bilateral eye involvement. Visual acuity improved in 21 of 73 patients (29%) by a mean of two Snellen chart lines after commencement of steroids. There was an increased likelihood of improved vision in the group who had intravenous steroids (40%) compared with those who received oral steroids (13%). In all except four patients (95%) vision remained stable at 1 month review. CONCLUSIONS Prompt treatment of GCA with steroids leads to improvement of visual acuity in a significant number of cases. Intravenous steroids may offer a greater prospect of improvement compared with oral steroids. A prospective trial comparing intravenous with oral steroids is needed to validate these findings and would not expose elderly patients to unacceptable risks.

Immunotherapy of ocular myasthenia gravis reduces conversion to generalized myasthenia gravis

Background Several retrospective studies have suggested that immunotherapy, including prednisolone, azathioprine and thymectomy, reduces progression of ocular myasthenia gravis to generalized myasthenia gravis. This study examines the effect of immunotherapy on generalization rates in ocular myasthenia patients who are acetylcholine receptor (AChR) antibody-positive. Methods Retrospective record review of 34 patients from three university-based hospitals with neurology and neuro-ophthalmology services in Australia. In all patients, positive AChR antibodies were recorded, the initial symptoms were purely ocular, and all had at least 2 years of follow-up. The patients who developed generalized myasthenia gravis were compared with those who remained purely ocular. Results There were 21 patients who developed generalized myasthenia gravis. Of these 21, only 2 (9.5%) had received prior immunotherapy. Among the 13 patients whose symptoms remained purely ocular, 10 (76.9%) had received prior immunotherapy. Conclusions In this study, most of the patients who progressed from ocular myasthenia to generalized myasthenia had not received prior immunotherapy. This study adds weight to the call for a prospective trial of early immunotherapy in patients with ocular myasthenia.

Carotid dissection: a common cause of Horner's syndrome

Purpose: To highlight that internal carotid artery dissection is a common cause of Horners syndrome and that it is important to diagnose dissection as anticoagulation can prevent carotid thrombosis and embolism.

Neuro-Otological Findings in Patients with Migraine-and Nonmigraine-Related Dizziness

This study presents the neuro-otological findings of 523 patients attending a tertiary vestibular clinic with migraine- and nonmigraine-related dizziness. Subjects were categorized into one of 4 groups, definite migrainous vertigo, probable migrainous vertigo, vestibular disorder coexisting with migraine and nonmigraine-related dizziness. No notable relationship was found between the numbers of abnormal findings between the groups for the majority of the neuro-otological tests. However, there was a significant trend in emetic response to caloric testing. The definite migrainous vertigo group were at least 4 times more likely to be nauseous to caloric testing than any other migraine category. This difference was independent of the magnitude of caloric responses between the emetic migraine groups. While further investigation is required, this study has potentially identified that nauseous/emetic response to caloric stimulation may be a distinguishing factor between migrainous vertigo and other vestibular disorders including those with a coexisting history of migraine.

Farms and Learning Partnerships in Farming Systems Projects: A Response to the Challenges of Complexity in Agricultural Innovation

Abstract Managing the competing interests of productivity growth, environmental concerns, landscape change and societal expectations presents challenges for agricultural industries. Innovation projects supporting knowledge development to address these challenges often involve partnerships with commercial farms, a methodology which promises much but has inherent challenges as well. This paper will examine the requirements of learning partnerships between farmers, research and extension (as members of innovation projects) to address conditions of complexity. We review designs for the involvement of commercial farms in innovation projects and explore the conditions for effective learning partnerships using two case studies from the Australian dairy industry. Learning partnerships with commercial farms can contribute to addressing the conditions of complexity faced by agricultural industries. Our analysis suggests that the conditions for effective learning partnerships involve the active negotiation of learning roles between farmers, researchers and advisors. This requires a unique form of facilitation to support the learning environment and use of learning tools, assisting project teams to act on complex issues. As learning partners, commercial farms in innovation projects are an effective response to the challenges of complexity in agricultural innovation.

Predictors of recurrent ischemic optic neuropathy in giant cell arteritis.

Background: The competing interests of preventing recurrent ischemic optic neuropathy (ION) and minimizing medication side effects make corticosteroid dose reduction in giant cell arteritis (GCA) a difficult problem. The authors sought to determine whether any factors were predictive of recurrent ION. Methods: Retrospective review of the records of 100 consecutive patients with biopsy-proven giant cell arteritis diagnosed in two Australian hospitals between 1988 and 1998. Among 67 patients who met inclusion criteria for ION in GCA, seven patients had recurrent ION. We compared the seven patients with recurrent ION to the 60 patients with nonrecurrent ION in terms of age, gender, mode of corticosteroid delivery, initial visual acuity in the affected eye, prevalence of bilateral ION, initial erythrocyte sedimentation rate (ESR) level, and rate of corticosteroid dose reduction. In the recurrent ION group, we documented the timing of the recurrence in relation to corticosteroid dose, elevation in acute phase reactants, and relapse of systemic symptoms. Results: We found recurrent ION in GCA in 10% of our cohort, higher than has been previously reported. Recurrences, all of which were ipsilateral, occurred from 3 to 36 months (median 8 months) after the initial ION. None of the clinical indicators the authors examined differed between the two groups. Six of seven patients with recurrent ION had elevations in ESR or C-reactive protein or a new headache at the time of ION recurrence, but in only one of these patients were these features recognized as preceding the recurrent ION. One patient had neither an elevation in acute phase reactants nor a relapse in systemic symptoms of GCA at the time of ION recurrence. Conclusions: Recurrent ION in GCA is difficult to predict. Although elevated acute phase reactants or new systemic symptoms consistent with GCA were present in six (83%) of our patients with ION recurrence, in only one patient (17%) did these events occur with enough lead time to allow caregivers to act preemptively. Thus, even very close monitoring of GCA patients with ION may not predict ION recurrence.

Water Security and Farming Systems: Implications for Advisory Practice and Policy-Making

Abstract Water issues are a feature of public debate in Australia. The increasing privatisation of water and changes to water allocation systems are resulting in change, often referred to as water ‘wars’ (de Villiers, 1999). The Australian dairy industry uses 25% of the surface irrigation water in Australia. How does a rural industry like dairying negotiate a future? What is the role of broker professions like extension in supporting change in this context? We focus on three critical issues to address these questions: farm-level adaptation; new technologies; and balancing environmental and productive water-use. Two case studies of farm decision-making and advisory practice suggest that managing complexity in water issues requires learning processes at three levels: farmer–advisor; advisors–policy; advisors–other disciplines–policy. We conclude there is a need for a framework to guide an ethical response to water policy, bringing farm adaptation and advisory practice to implement change.

Aligning farm decision making and genetic information systems to improve animal production: methodology and findings from the Australian dairy industry

To date there has been little research into the way genetic improvement decisions are made in practice on Australian farms. This type of knowledge is important for guiding the design of programs to increase the use of genetic information and thereby the rate of genetic gain in animal production systems. This paper describes an approach to understanding farm decision making in order to improve the design of services to increase the use of genetic information in the Australian dairy industry. A mixed-method approach involving a national survey and regional focus groups was used to determine farmers’ perceptions of the genetic information system overall and the key features of bull selection decisions and information sources. The current genetic information system was found to have a strong reputation for ease of access, use and fit with the way farmers evaluated bulls. In the focus groups the farmers described their decision process as having an ‘ideal cow’ in mind that fitted their farming system (e.g. balancing survival, milk volume, milk components, mammary features, fertility, milking speed, etc.). Bull proofs were then screened to identify a batch of eligible bulls that were further screened for their specific situation. Focus groups of advisers generally concurred with the process described by farmers. Further, farmers tended to rely on one or two main information sources in making decisions. To address the issue of greater alignment between farmer decision making and use of genetic information through industry organisations requires a coordinated strategy and a comprehensive development program. Suggestions for activities to this end are outlined.

Retinal manifestations of ophthalmic artery hypoperfusion

Ophthalmic artery hypoperfusion is a relatively uncommon clinical entity. This study illustrates the posterior segment findings of ophthalmic artery hypoperfusion in a series of nine patients. Colour photographs and relevant fluorescein angiograms highlighting the findings are shown. The retinal manifestations of ophthalmic artery hypoperfusion in this series of patients include midperipheral haemorrhages, dilated retinal veins, optic disk collaterals, optic disk neovascularization, cotton wool spots, grey intraretinal lesions, fundus pallor, optic disk swelling and choroidal infarcts. Recognition of the ophthalmic changes in this condition may lead to detection of carotid artery disease, the surgical and medical treatment of which has important bearing on patient management.