Optometry and Vision Sciences - Research Publications
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ItemThe Short-Term Compliance and Concordance to in Clinic Testing for Tablet-Based Home Monitoring in Age-Related Macular Degeneration(ELSEVIER SCIENCE INC, 2022-03-01)PURPOSE: The aim of this study was to determine the short-term compliance with regular home monitoring of macular retinal sensitivity (RS) in intermediate age-related macular degeneration (iAMD). Home-based outcomes were compared with in-clinic outcomes determined using (1) the same tablet device under supervision, and (2) the Macular Integrity Assessment (MaIA) microperimeter. DESIGN: Single-center longitudinal compliance and reliability study. METHODS: A total of 73 participants with iAMD were trained to perform macular field testing with the Melbourne Rapid Fields-macular (MRF-m) iPad application. Volunteers were asked to return 6 weekly tests from home, guided by audio instructions. We determined compliance with weekly testing and surveyed for factors that limited compliance. Test reliability (false positive, false negative) and RS were compared to in-clinic assays (MaIA). Data are given as mean ± SD or as median [quartile 1-3 range]. Group comparisons were achieved with bootstrap to define the 95% confidence limits. RESULTS: A total of 59 participants submitted 6 home examinations with a median intertest interval of 8.0 [7.0-17] days. Compliance with weekly testing (7 days ±24 hours) was 55%. The main barrier to compliance was information technology (IT) logistic reasons. Of 694 home examinations submitted, 96% were reliable (false-positive results <25%). The mean RS returned by the tablet was significantly higher (+3.2 dB, P < .05) compared to the MaIA. CONCLUSIONS: Home monitoring produces reliable results that differ from in-clinic tests because of test design. This should not affect self-monitoring once an at-home baseline is established, but these differences will affect comparisons with in-clinic outcomes. Reasonable compliance with weekly testing was achieved. Improved IT support might lead to better compliance.
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ItemRelationship between reticular pseudodrusen and choroidal thickness in intermediate age-related macular degeneration(WILEY, 2018-07-01)IMPORTANCE: Reticular pseudodrusen (RPD) is strongly associated with late age-related macular degeneration (AMD) but their aetiology remains unknown. RPD have been associated with reduced choroidal thickness (ChT) but most studies are limited by small sample size and varying severity of AMD. BACKGROUND: To investigate the relationship between choroidal thickness and RPD in eyes with intermediate AMD (iAMD), controlling for variables known to influence ChT. DESIGN: Retrospective cohort study. PARTICIPANTS: Participants were recruited from Centre for Eye Research Australia. METHODS: Colour fundus photographs, fundus auto fluorescence, near-infrared and spectral-domain ocular coherence tomography (OCT) were graded for RPD. ChT was measured from enhanced-depth imaging OCT scans at the centre of fovea, 1500 and 3000 μm nasal, temporal, superior and inferior from centre of fovea. MAIN OUTCOME MEASURES: ChT between RPD and non-RPD group. RESULTS: A total of 297 eyes from 152 subjects were included. A total of 84 (28%) had RPD and were older than non-RPD group (75.1 ± 5.4 years and 68.7 ± 6.9 years, respectively; P < 0.001). In unadjusted analysis, the RPD group was significantly associated with thinner choroids across all measured locations (P ≤ 0.022). After adjustment for variables, the presence of RPD was no longer associated with ChT (P ≥ 0.132 for all locations) but age (P < 0.001) and refractive error (P = 0.002) remained significantly associated with ChT. CONCLUSIONS AND RELEVANCE: Age and refractive error, rather than RPD, was significantly associated with reduced ChT in eyes with iAMD. Choroidal insufficiency may be a less important variable in RPD aetiology than previously considered.
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ItemClinical audit as an educative tool for optometrists: an intervention study in age-related macular degeneration(WILEY, 2021-01)Purpose Age‐related macular degeneration (AMD) is a major cause of vision loss. This study investigated whether performing clinical audit and receiving analytical performance feedback altered documentation of the AMD care provided by optometrists. Methods Australian optometrists were recruited and completed a survey about their demographics and confidence in AMD care, and a three‐month audit of their practice records using an AMD audit tool (termed the pre‐audit evaluation). After receiving analytical feedback, participants identified areas for improvement and re‐audited their practices after three months to analyse changes in performance (termed the post‐audit evaluation). Paired t‐tests and Wilcoxon signed‐rank tests, as appropriate, were used to compare pre‐ and post‐audit data. Results Twenty optometrists, most practising in Victoria, Australia, completed the study. Participants primarily worked in corporate practice and/or rural settings and had a range of optometric experience (2–40 years). At baseline, participants felt confident in their: knowledge of AMD risk factors (65%), advice to patients about these factors (55%) and management of earlier stages of AMD (55%). Each clinician completed (median [IQR]): 15 [IQR: 10–19] and 12 [IQR: 8–16] audits of unique patient records, pre‐ and post‐audit, respectively. Post‐audit, average record documentation (per optometrist) improved for asking about: AMD family history (94% to 100%, p = 0.03), smoking status (21% to 58%, p < 0.01), diet (11% to 29%, p < 0.01) and nutritional supplementation (20% to 51%, p < 0.01). For clinical examination, compliance with documenting pinhole visual acuity, performing an in‐office Amsler grid (upon indication) and using optical coherence tomography improved post‐audit (p < 0.05). Accuracy of severity documentation improved for earlier stages of AMD (p < 0.05). For earlier stages of AMD, documentation of counselling about modifiable risk factors significantly improved post‐audit (p < 0.05). Aspects well‐performed pre‐audit that did not change included documenting: medical histories (100% at both time points, p = 0.06) and retinal imaging (77% at both time points, p = 0.97). Conclusions Self‐audit with analytical feedback improved clinical record documentation of: AMD risk factors, clinical examination, AMD severity classification and management advice. These findings support a role for audit to improve optometric clinical care of AMD, as evidenced by improved documentation of the AMD care delivered.
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ItemUptake, Persistence, and Performance of Weekly Home Monitoring of Visual Field in a Large Cohort of Patients With Glaucoma(ELSEVIER SCIENCE INC, 2021-03-01)PURPOSE: This study examines the short-term uptake, compliance, and performance of a tablet device used for home monitoring of visual field (VF-Home) by glaucoma patients. DESIGN: Single-center, observational, longitudinal, compliance study. METHODS: Participants who were glaucoma suspects or had stable glaucoma in at least one eye were recruited during a regular clinic review. Baseline in-clinic visual field (VF) was recorded with the Humphrey Field Analyser (HFA, SITA standard) and repeated at 6 months. Participants were tasked with performing 6 VF examinations from home, at weekly intervals, using a loaned iPad tablet. Uptake was defined as returning at least 1 test from home. Reliability and global indices from VF-Home were compared to in-clinic outcomes. Data are shown as either mean ± [standard deviation] or median [quartile 1-3 range], and group comparisons were achieved with bootstrap. RESULTS: We recruited 186 eyes of 101 participants. VF-Home uptake was excellent, with 88% of participants successfully completing ≥1 home examination and 69% completing all 6 examinations. The median duration between tests was 7.0 [7.0-8.0] days. Barriers to uptake and compliance involved information technology (IT) logistical reasons, lack of motivation, or competing life demands. VF-Home gave greater fixation loss but a similar level of False Positives (FP) as the HFA. A high correlation was found for the mean defect between in-clinic and at-home outcomes (R = 0.85). CONCLUSIONS: VF-Home can return a high level of short-term compliance and results comparable to those found by in-clinic testing. IT logistical reasons and lack of motivation are barriers to uptake and compliance.
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ItemNo Preview AvailableneuroBi: A Highly Configurable Neurostimulator for a Retinal Prosthesis and Other Applications(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2015-01-01)To evaluate the efficacy of a suprachoroidal retinal prosthesis, a highly configurable external neurostimulator is required. In order to meet functional and safety specifications, it was necessary to develop a custom device. A system is presented which can deliver charge-balanced, constant-current biphasic pulses, with widely adjustable parameters, to arbitrary configurations of output electrodes. This system is shown to be effective in eliciting visual percepts in a patient with approximately 20 years of light perception vision only due to retinitis pigmentosa, using an electrode array implanted in the suprachoroidal space of the eye. The flexibility of the system also makes it suitable for use in a number of other emerging clinical neurostimulation applications, including epileptic seizure suppression and closed-loop deep brain stimulation. Clinical trial registration number NCT01603576 (www.clinicaltrials.gov).
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ItemNo Preview AvailableCan HMG Co-A reductase inhibitors ("statins") slow the progression of age-related macular degeneration? The Age-Related Maculopathy Statin Study (ARMSS)(DOVE MEDICAL PRESS LTD, 2008-01-01)Age-related macular degeneration (AMD) is responsible for the majority of visual impairment in the Western world. The role of cholesterol-lowering medications, HMG Co-A reductase inhibitors or statins, in reducing the risk of AMD or of delaying its progression has not been fully investigated. A 3-year prospective randomized controlled trial of 40 mg simvastatin per day compared to placebo in subjects at high risk of AMD progression is described. This paper outlines the primary aims of the Age-Related Maculopathy Statin Study (ARMSS), and the methodology involved. Standardized clinical grading of macular photographs and comparison of serial macular digital photographs, using the International grading scheme, form the basis for assessment of primary study outcomes. In addition, macular function is assessed at each visit with detailed psychophysical measurements of rod and cone function. Information collected in this study will assist in the assessment of the potential value of HMG Co-A reductase inhibitors (statins) in reducing the risk of AMD progression.
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ItemAdvances in implantable bionic devices for blindness: a review(WILEY, 2016-09-01)Since the 1950s, vision researchers have been working towards the ambitious goal of restoring a functional level of vision to the blind via electrical stimulation of the visual pathways. Groups based in Australia, USA, Germany, France and Japan report progress in the translation of retinal visual prosthetics from the experimental to clinical domains, with two retinal visual prostheses having recently received regulatory approval for clinical use. Regulatory approval for cortical visual prostheses is yet to be obtained; however, several groups report plans to conduct clinical trials in the near future, building upon the seminal clinical studies of Brindley and Dobelle. In this review, we discuss the general principles of visual prostheses employing electrical stimulation of the visual pathways, focusing on the retina and visual cortex as the two most extensively studied stimulation sites. We also discuss the surgical and functional outcomes reported to date for retinal and cortical prostheses, concluding with a brief discussion of novel developments in this field and an outlook for the future.
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ItemPerformance of a Defect-Mapping Microperimetry Approach for Characterizing Progressive Changes in Deep Scotomas(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2019-07-01)PURPOSE: To examine whether a microperimetry testing strategy based on quantifying the spatial extent of functional abnormalities (termed "defect-mapping" strategy) could improve the detection of progressive changes in deep scotomas compared to the conventional thresholding strategy. METHODS: A total of 30 healthy participants underwent two microperimetry examinations, each using the defect-mapping and thresholding strategies at the first visit to examine the test-retest variability of each method. Testing was performed using an isotropic stimulus pattern centered on the optic nerve head (ONH), which acted as a model of a deep scotoma. These tests were repeated at a second visit, except using a smaller stimulus pattern and thereby increasing the proportion of test locations falling within the ONH (to simulate the progressive enlargement of a deep scotoma). The extent of change detected between visits relative to measurement variability was compared between the two strategies. RESULTS: Relative to their effective dynamic ranges, the test-retest variability of the defect-mapping strategy (1.8%) was significantly lower compared to the thresholding strategy (3.3%; P < 0.001). The defect-mapping strategy also captured a significantly greater extent of change between visits relative to variability (-4.70 t-1) compared to the thresholding strategy (2.74 t-1; P < 0.001). CONCLUSIONS: A defect-mapping microperimetry testing strategy shows promise for capturing the progressive enlargement of deep scotomas more effectively than the conventional thresholding strategy. TRANSLATIONAL RELEVANCE: Microperimetry testing with the defect-mapping strategy could provide a more accurate clinical trial outcome measure for capturing progressive changes in deep scotomas in eyes with atrophic retinal diseases, warranting further investigations.
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ItemNovel measures of cardiovascular health and its association with prevalence and progression of age-related macular degeneration: the CHARM study(BMC, 2008-01-01)BACKGROUND: To determine if novel measures of cardiovascular health are associated with prevalence or progression of age-related macular degeneration (AMD). METHODS: Measures of the cardiovascular system: included intima media thickness (IMT), pulse wave velocity (PWV), systemic arterial compliance (SAC), carotid augmentation index (AI). For the prevalence study, hospital-based AMD cases and population-based age- and gender-matched controls with no signs of AMD in either eye were enrolled. For the progression component, participants with early AMD were recruited from two previous studies; cases were defined as progression in one or both eyes and controls were defined as no progression in either eye. RESULTS: 160 cases and 160 controls were included in the prevalence component. The upper two quartiles of SAC, implying good cardiovascular health, were significantly associated with increased risk of AMD (OR = 2.54, 95% CL = 1.29, 4.99). High PWV was associated with increased prevalent AMD. Progression was observed in 82 (32.3%) of the 254 subjects recruited for the progression component. Higher AI (worse cardiovascular function) was protective for AMD progression (OR = 0.30, 95%CL = 0.13, 0.69). Higher aortic PWV was associated with increased risk of AMD progression; the highest risk was seen with the second lowest velocity (OR = 6.22, 95% CL = 2.35, 16.46). CONCLUSION: The results were unexpected in that better cardiovascular health was associated with increased risk of prevalent AMD and progression. Inconsistent findings between the prevalence and progression components could be due to truly different disease etiologies or to spurious findings, as can occur with inherent biases in case control studies of prevalence. Further investigation of these non-invasive methods of characterizing the cardiovascular system should be undertaken as they may help to further elucidate the role of the cardiovascular system in the etiology of prevalent AMD and progression.