Central retinal artery occlusion (CRAO) is an ocular emergency and is the ocular analogue of cere... more Central retinal artery occlusion (CRAO) is an ocular emergency and is the ocular analogue of cerebral stroke. It results in profound, usually monocular vision loss, and is associated with significant functional morbidity. The risk factors for CRAO are the same atherosclerotic risk factors as for stroke and heart disease. As such, individuals with CRAO may be at risk of ischemic end organ damage such as a cerebral stroke. Therefore, the management of CRAO is not only to restore vision, but at the same time to manage risk factors that may lead to other vascular conditions. There are a number of therapies that has been used in the treatment of CRAO in the past. These include carbogen inhalation, acetazolamide infusion, ocular massage and paracentesis, as well as various vasodilators such as intravenous glyceryl trinitrate. None of these "standard agents" have been shown to alter the natural history of disease definitively. There has been recent interest shown in the use of th...
Purpose: Age-related macular degeneration (AMD) is a degenerative condition impacting central vis... more Purpose: Age-related macular degeneration (AMD) is a degenerative condition impacting central vision. Evaluating the effectiveness of low vision devices provides empirical evidence on how devices can rehabilitate and overcome deficits caused by AMD. This evidence could help to facilitate discussion on necessary future improvements to vision enhancement technology.Methods: A systematic review of the literature was conducted on low vision devices use in AMD populations. Relevant peer-reviewed research articles from six databases were screened. Results: The findings of thirty-five studies revealed a significant positive impact of low vision devices leading to improvements in visual acuity, reading performance, facial recognition, and more. While the studies were found to have moderate risks of bias, a GRADE assessment of the evidence suggested the certainty of the evidence was low-moderate.Discussion: Simple hand-held low vision devices (e.g., magnifiers) appear to currently have great...
Background and Purpose: Central retinal artery occlusion results in sudden, painless, usually per... more Background and Purpose: Central retinal artery occlusion results in sudden, painless, usually permanent loss of vision in the affected eye. There is no proven, effective treatment to salvage visual acuity and a clear, unmet need for an effective therapy. In this work, we evaluated the efficacy of intravenous tissue-type plasminogen activator (IV alteplase) in a prospective cohort study and an updated systematic review and meta-analysis. Methods: We enrolled consecutive patients with acute central retinal artery occlusion within 48 hours of symptoms onset and with a visual acuity of <20/200 from January 2009 until May 2019. The primary outcomes were safety and functional visual acuity recovery. We compared rates of visual recovery between those treated with alteplase within 4.5 hours of symptom onset to those who did not receive alteplase (including an analysis restricted to untreated patients presenting within the window for treatment). We incorporated these results into an updat...
Background To describe a rare presentation of vertebral artery dissection (VAD) as a small but co... more Background To describe a rare presentation of vertebral artery dissection (VAD) as a small but congruous incomplete homonymous hemianopia demonstrating use of visual field testing in the diagnosis. Case presentation A 30 year old woman had been unwell for 4 months with difficulty focusing, vertigo, dizziness and a feeling of falling to the right. A small but congruous right inferior homonymous quadrantanopia was found on examination leading to further investigation that uncovered a vertebral artery dissection and multiple posterior circulation infarctions including a left occipital stroke matching the field defect. Conclusions We describe an atypical case of VAD presenting with a small congruous quadrantanopia. This is a rare but significant condition that predisposes to multiple thromboembolic infarction that may be easily misdiagnosed and a high index of suspicion is required to make the diagnosis.
Background and Purpose— Central retinal artery occlusion results in acute visual loss with poor s... more Background and Purpose— Central retinal artery occlusion results in acute visual loss with poor spontaneous recovery. Current standard therapies do not alter the natural history of disease. Several open-label clinical studies using continuous infusion of thrombolytic agents have suggested that local intraarterial fibrinolysis (LIF) is efficacious in the treatment of central retinal artery occlusion. The aim is to compare the visual outcome in patients with acute central retinal artery occlusion of presumed thromboembolic etiology treated with LIF administered in aliquots with that of patients treated with standard therapy. Methods— We conducted a single-center, nonrandomized interventional study of consecutive patients with acute central retinal artery occlusion from July 1999 to July 2006. Results— Twenty-one patients received LIF and 21 received standard therapy. Seventy-six percent of subjects in the LIF group had a visual acuity improvement of one line or more compared with 33% ...
Objective:To investigate the current information sources of patients with multiple sclerosis (MS)... more Objective:To investigate the current information sources of patients with multiple sclerosis (MS) in the early stages of their disease and to identify patients’ preferred source of information. The relative amounts of information from the different sources were also compared.Methods:Participants at a newly diagnosed information session organized by the Multiple Sclerosis Society of South Australia were invited to complete a questionnaire. Participants were asked to rate on a visual analog scale how much information they had received about MS and optic neuritis from different information sources and how much information they would like to receive from each of the sources.Results:A close to ideal amount of information is being provided by the MS society and MS specialist nurses. There is a clear deficit between what information patients are currently receiving and the amount of information they actually want from various sources. Patients wish to receive significantly more information from treating general practitioners, eye specialists, neurologists, and education sessions. Patients have identified less than adequate information received on optic neuritis from all sources.Conclusion:This study noted a clear information deficit regarding MS from all sources. This information deficit is more pronounced in relation to optic neuritis and needs to be addressed in the future.Practice implications:More patient information and counselling needs to be provided to MS patients even at early stages of their disease, especially in relation to management of disease relapse.
Purpose: Investigating difficulties during activities of daily living is a fundamental first step... more Purpose: Investigating difficulties during activities of daily living is a fundamental first step for the development of intervention and rehabilitation strategies. One way to do this is through visual impairment simulations. The aim of this review is to synthesise and assess the types of simulation methods that have been used to simulate age-related macular degeneration (AMD) in normally sighted participants, during activities of daily living (e.g., reading, cleaning, cooking).Methods: We conducted a systematic literature search in five databases and a critical analysis of the advantages and disadvantages of various AMD simulation methods (following PRISMA guidelines). The review focuses on the suitability of each method for investigating activities of daily living, an assessment of clinical validation procedures, and an evaluation of the adaptation periods for participants. Results: Nineteen studies met the criteria for inclusion. Contact lenses, computer manipulations, gaze conti...
Developing an understanding of how virtual reality (VR) aftereffects may influence later activiti... more Developing an understanding of how virtual reality (VR) aftereffects may influence later activities could help to minimise the risk of using head-mounted displays (HMDs) for various applications. This study investigated the visual and cognitive aftereffects of using HMDs and their relationship to the reporting of VR sickness symptoms. Visual (accommodation and vergence) and cognitive (reaction time and rapid visual processing) assessments were employed before and after participants engage in a 30-minute VR table tennis game (VR group, n = 27) or went about their daily activities (control group, n = 28). VR sickness symptoms were captured using the Simulator Sickness Questionnaire (SSQ). The data showed changes in accommodation but no concurrent changes in vergence, which likely stems from decoupling accommodation and vergence in VR. Furthermore, larger changes in accommodation were linked to a greater reporting of sickness symptoms suggesting that decoupling accommodation and vergen...
Homonymous hemianopia post-stroke reduces independence. To compare the effectiveness of a standar... more Homonymous hemianopia post-stroke reduces independence. To compare the effectiveness of a standardised program versus current individualized therapy in patients with homonymous hemianopia. Single-blind randomized controlled trial, 24 patients (54% male), mean age (65±4.3), mean time since stroke (51±52.3 days), recruited from rehabilitation and vision services in Adelaide, Australia. Participants were randomized to a combined standardized scanning and mobility program of 7 weeks, 3 times per week or to individualized therapy recommended by clinicians. Primary outcome was an assessment of scanning ability whilst walking. Secondary outcomes included measures of visual scanning, reading, and vision related quality of life (QOL). No significant differences were found between intervention groups for the primary outcome measure of scanning ability whilst walking at 7 weeks and at 3 months (P > 0.05). However, at 3 months significant differences were found for the QOL National Eye Insti...
Spatial neglect after stroke can be a challenging syndrome to diagnose under standard neuropsycho... more Spatial neglect after stroke can be a challenging syndrome to diagnose under standard neuropsychological assessment. There is now sufficient evidence that those affected might demonstrate neglect behavior in everyday settings despite showing no signs of neglect during common neglect tasks. This discrepancy is attributed to the simplified and unrealistic nature of common pen and paper based tasks that do not match the demanding, novel, and complex environment of everyday life. As such, increasing task demands under more ecologically valid scenarios has become an important method of increasing test sensitivity. The main aim of the current study was to evaluate the diagnostic utility of the Mobility Assessment Course (MAC), an ecological task, for the assessment of neglect. If neglect becomes more apparent under more challenging task demands the MAC could prove to be more diagnostically accurate at detecting neglect than conventional methods, particularly as the time from initial brain...
Central retinal artery occlusion (CRAO) is an ocular emergency and is the ocular analogue of cere... more Central retinal artery occlusion (CRAO) is an ocular emergency and is the ocular analogue of cerebral stroke. It results in profound, usually monocular vision loss, and is associated with significant functional morbidity. The risk factors for CRAO are the same atherosclerotic risk factors as for stroke and heart disease. As such, individuals with CRAO may be at risk of ischemic end organ damage such as a cerebral stroke. Therefore, the management of CRAO is not only to restore vision, but at the same time to manage risk factors that may lead to other vascular conditions. There are a number of therapies that has been used in the treatment of CRAO in the past. These include carbogen inhalation, acetazolamide infusion, ocular massage and paracentesis, as well as various vasodilators such as intravenous glyceryl trinitrate. None of these "standard agents" have been shown to alter the natural history of disease definitively. There has been recent interest shown in the use of th...
Purpose: Age-related macular degeneration (AMD) is a degenerative condition impacting central vis... more Purpose: Age-related macular degeneration (AMD) is a degenerative condition impacting central vision. Evaluating the effectiveness of low vision devices provides empirical evidence on how devices can rehabilitate and overcome deficits caused by AMD. This evidence could help to facilitate discussion on necessary future improvements to vision enhancement technology.Methods: A systematic review of the literature was conducted on low vision devices use in AMD populations. Relevant peer-reviewed research articles from six databases were screened. Results: The findings of thirty-five studies revealed a significant positive impact of low vision devices leading to improvements in visual acuity, reading performance, facial recognition, and more. While the studies were found to have moderate risks of bias, a GRADE assessment of the evidence suggested the certainty of the evidence was low-moderate.Discussion: Simple hand-held low vision devices (e.g., magnifiers) appear to currently have great...
Background and Purpose: Central retinal artery occlusion results in sudden, painless, usually per... more Background and Purpose: Central retinal artery occlusion results in sudden, painless, usually permanent loss of vision in the affected eye. There is no proven, effective treatment to salvage visual acuity and a clear, unmet need for an effective therapy. In this work, we evaluated the efficacy of intravenous tissue-type plasminogen activator (IV alteplase) in a prospective cohort study and an updated systematic review and meta-analysis. Methods: We enrolled consecutive patients with acute central retinal artery occlusion within 48 hours of symptoms onset and with a visual acuity of <20/200 from January 2009 until May 2019. The primary outcomes were safety and functional visual acuity recovery. We compared rates of visual recovery between those treated with alteplase within 4.5 hours of symptom onset to those who did not receive alteplase (including an analysis restricted to untreated patients presenting within the window for treatment). We incorporated these results into an updat...
Background To describe a rare presentation of vertebral artery dissection (VAD) as a small but co... more Background To describe a rare presentation of vertebral artery dissection (VAD) as a small but congruous incomplete homonymous hemianopia demonstrating use of visual field testing in the diagnosis. Case presentation A 30 year old woman had been unwell for 4 months with difficulty focusing, vertigo, dizziness and a feeling of falling to the right. A small but congruous right inferior homonymous quadrantanopia was found on examination leading to further investigation that uncovered a vertebral artery dissection and multiple posterior circulation infarctions including a left occipital stroke matching the field defect. Conclusions We describe an atypical case of VAD presenting with a small congruous quadrantanopia. This is a rare but significant condition that predisposes to multiple thromboembolic infarction that may be easily misdiagnosed and a high index of suspicion is required to make the diagnosis.
Background and Purpose— Central retinal artery occlusion results in acute visual loss with poor s... more Background and Purpose— Central retinal artery occlusion results in acute visual loss with poor spontaneous recovery. Current standard therapies do not alter the natural history of disease. Several open-label clinical studies using continuous infusion of thrombolytic agents have suggested that local intraarterial fibrinolysis (LIF) is efficacious in the treatment of central retinal artery occlusion. The aim is to compare the visual outcome in patients with acute central retinal artery occlusion of presumed thromboembolic etiology treated with LIF administered in aliquots with that of patients treated with standard therapy. Methods— We conducted a single-center, nonrandomized interventional study of consecutive patients with acute central retinal artery occlusion from July 1999 to July 2006. Results— Twenty-one patients received LIF and 21 received standard therapy. Seventy-six percent of subjects in the LIF group had a visual acuity improvement of one line or more compared with 33% ...
Objective:To investigate the current information sources of patients with multiple sclerosis (MS)... more Objective:To investigate the current information sources of patients with multiple sclerosis (MS) in the early stages of their disease and to identify patients’ preferred source of information. The relative amounts of information from the different sources were also compared.Methods:Participants at a newly diagnosed information session organized by the Multiple Sclerosis Society of South Australia were invited to complete a questionnaire. Participants were asked to rate on a visual analog scale how much information they had received about MS and optic neuritis from different information sources and how much information they would like to receive from each of the sources.Results:A close to ideal amount of information is being provided by the MS society and MS specialist nurses. There is a clear deficit between what information patients are currently receiving and the amount of information they actually want from various sources. Patients wish to receive significantly more information from treating general practitioners, eye specialists, neurologists, and education sessions. Patients have identified less than adequate information received on optic neuritis from all sources.Conclusion:This study noted a clear information deficit regarding MS from all sources. This information deficit is more pronounced in relation to optic neuritis and needs to be addressed in the future.Practice implications:More patient information and counselling needs to be provided to MS patients even at early stages of their disease, especially in relation to management of disease relapse.
Purpose: Investigating difficulties during activities of daily living is a fundamental first step... more Purpose: Investigating difficulties during activities of daily living is a fundamental first step for the development of intervention and rehabilitation strategies. One way to do this is through visual impairment simulations. The aim of this review is to synthesise and assess the types of simulation methods that have been used to simulate age-related macular degeneration (AMD) in normally sighted participants, during activities of daily living (e.g., reading, cleaning, cooking).Methods: We conducted a systematic literature search in five databases and a critical analysis of the advantages and disadvantages of various AMD simulation methods (following PRISMA guidelines). The review focuses on the suitability of each method for investigating activities of daily living, an assessment of clinical validation procedures, and an evaluation of the adaptation periods for participants. Results: Nineteen studies met the criteria for inclusion. Contact lenses, computer manipulations, gaze conti...
Developing an understanding of how virtual reality (VR) aftereffects may influence later activiti... more Developing an understanding of how virtual reality (VR) aftereffects may influence later activities could help to minimise the risk of using head-mounted displays (HMDs) for various applications. This study investigated the visual and cognitive aftereffects of using HMDs and their relationship to the reporting of VR sickness symptoms. Visual (accommodation and vergence) and cognitive (reaction time and rapid visual processing) assessments were employed before and after participants engage in a 30-minute VR table tennis game (VR group, n = 27) or went about their daily activities (control group, n = 28). VR sickness symptoms were captured using the Simulator Sickness Questionnaire (SSQ). The data showed changes in accommodation but no concurrent changes in vergence, which likely stems from decoupling accommodation and vergence in VR. Furthermore, larger changes in accommodation were linked to a greater reporting of sickness symptoms suggesting that decoupling accommodation and vergen...
Homonymous hemianopia post-stroke reduces independence. To compare the effectiveness of a standar... more Homonymous hemianopia post-stroke reduces independence. To compare the effectiveness of a standardised program versus current individualized therapy in patients with homonymous hemianopia. Single-blind randomized controlled trial, 24 patients (54% male), mean age (65±4.3), mean time since stroke (51±52.3 days), recruited from rehabilitation and vision services in Adelaide, Australia. Participants were randomized to a combined standardized scanning and mobility program of 7 weeks, 3 times per week or to individualized therapy recommended by clinicians. Primary outcome was an assessment of scanning ability whilst walking. Secondary outcomes included measures of visual scanning, reading, and vision related quality of life (QOL). No significant differences were found between intervention groups for the primary outcome measure of scanning ability whilst walking at 7 weeks and at 3 months (P > 0.05). However, at 3 months significant differences were found for the QOL National Eye Insti...
Spatial neglect after stroke can be a challenging syndrome to diagnose under standard neuropsycho... more Spatial neglect after stroke can be a challenging syndrome to diagnose under standard neuropsychological assessment. There is now sufficient evidence that those affected might demonstrate neglect behavior in everyday settings despite showing no signs of neglect during common neglect tasks. This discrepancy is attributed to the simplified and unrealistic nature of common pen and paper based tasks that do not match the demanding, novel, and complex environment of everyday life. As such, increasing task demands under more ecologically valid scenarios has become an important method of increasing test sensitivity. The main aim of the current study was to evaluate the diagnostic utility of the Mobility Assessment Course (MAC), an ecological task, for the assessment of neglect. If neglect becomes more apparent under more challenging task demands the MAC could prove to be more diagnostically accurate at detecting neglect than conventional methods, particularly as the time from initial brain...
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