Optometry and Vision Sciences - Research Publications

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    Genetics of reticular pseudodrusen in age-related macular degeneration
    Farashi, S ; Ansell, BRE ; Wu, Z ; Abbott, CJ ; Pebay, A ; Fletcher, EL ; Guymer, RH ; Bahlo, M (CELL PRESS, 2022-04)
    Reticular pseudodrusen (RPD) are subretinal deposits and when observed with age-related macular degeneration (AMD) form a distinct phenotype, often associated with late-stage disease. To date, RPD genetic risk-associations overlap six well-established AMD-risk regions. Determining RPD-specific underlying genetic causes by utilising adequate imaging methods should improve our understanding of the pathophysiology of RPD.
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    Reticular pseudodrusen: A critical phenotype in age-related macular degeneration
    Wu, Z ; Fletcher, EL ; Kumar, H ; Greferath, U ; Guymer, RH (PERGAMON-ELSEVIER SCIENCE LTD, 2022-05)
    Reticular pseudodrusen (RPD), or subretinal drusenoid deposits (SDD), refer to distinct lesions that occur in the subretinal space. Over the past three decades, their presence in association with age-related macular degeneration (AMD) has become increasingly recognized, especially as RPD have become more easily distinguished with newer clinical imaging modalities. There is also an increasing appreciation that RPD appear to be a critical AMD phenotype, where understanding their pathogenesis will provide further insights into the processes driving vision loss in AMD. However, key barriers to understanding the current evidence related to the independent impact of RPD include the heterogeneity in defining their presence, and failure to account for the confounding impact of the concurrent presence and severity of AMD pathology. This review thus critically discusses the current evidence on the prevalence and clinical significance of RPD and proposes a clinical imaging definition of RPD that will help move the field forward in gathering further key knowledge about this critical phenotype. It also proposes a putative mechanism for RPD formation and how they may drive progression to vision loss in AMD, through examining current evidence and presenting novel findings from preclinical and clinical studies.
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    The Short-Term Compliance and Concordance to in Clinic Testing for Tablet-Based Home Monitoring in Age-Related Macular Degeneration
    Prea, SM ; Kong, GYX ; Guymer, RH ; Sharangan, P ; Baglin, EK ; Vingrys, AJ (ELSEVIER SCIENCE INC, 2022-03)
    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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    Clinical audit as an educative tool for optometrists: an intervention study in age-related macular degeneration
    Gocuk, SA ; Lee, J-H ; Keller, PR ; Ayton, LN ; Guymer, RH ; McKendrick, AM ; Downie, LE (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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    Uptake, Persistence, and Performance of Weekly Home Monitoring of Visual Field in a Large Cohort of Patients With Glaucoma
    Prea, SM ; Kong, GYX ; Guymer, RH ; Vingrys, AJ (ELSEVIER SCIENCE INC, 2021-03)
    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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    Investigating the discrepancy between MAIA and MP-1 microperimetry results
    Xu, L ; Wu, Z ; Guymer, RH ; Anderson, AJ (WILEY, 2021-11)
    PURPOSE: Previous work has suggested that sensitivities measured on the iCare MAIA and Nidek MP-1 microperimeters differ systematically, although it is unclear whether one or both devices are inaccurate. Here, we assess the discrepancy between these two instruments as well as with a rigorous reference standard. METHODS: Fifteen healthy participants underwent visual field testing on the MAIA and MP-1 microperimeters. Results were compared to a reference measure of increment thresholds on a laboratory-based, calibrated computer monitor system using the same background luminance and target size. Discrepancies were assessed as a function of eccentricity along the vertical meridian. Differences in decibels (dB) due to differences in the maximum stimulus luminance between devices were accounted for mathematically. RESULTS: The mean sensitivity measured with the MAIA was <1 dB lower than laboratory-based measures, which was statistically significant but of limited clinical importance. In contrast, the mean sensitivity measured with the MP-1 was >8 dB lower than the laboratory measures. The difference was greater for an eccentric superior retinal location, in contrast to what would be predicted if the discrepancy was due to a ceiling effect caused by the MP-1's limited dynamic range. CONCLUSIONS: While MAIA measurements showed low bias compared with our rigorously determined reference standard, the MP-1 showed large discrepancies that could not be explained purely by the limited dynamic range of the instrument. MAIA and MP-1 sensitivity values cannot be compared directly, and caution is advised when assessing absolute sensitivities or eccentricity effects in the extensive MP-1 literature.