Melbourne School of Population and Global Health - Research Publications
Permanent URI for this collection
Search Results
1 - 5 of 5
-
Item
-
ItemRelationship between reticular pseudodrusen and choroidal thickness in intermediate age-related macular degeneration(WILEY, 2018-07)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.
-
ItemPresymptomatic Retinal Sensitivity Changes in Intermediate Age-Related Macular Degeneration Associated With New Retinal Fluid(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2019-11)PURPOSE: To determine whether change in retinal sensitivity in areas with subretinal or intraretinal fluid secondary to age-related macular degeneration (AMD) precedes visual symptoms. If confirmed, retinal sensitivity testing could be used for home monitoring in AMD. METHODS: Individuals with intermediate AMD enrolled in a longitudinal study were seen every 6 months and underwent best-corrected visual acuity testing (BCVA), spectral domain-optical coherence tomography (SD-OCT), and microperimetry. Asymptomatic individuals who developed incidental, reading center-determined retinal fluid detected on SD-OCT were identified. The point-wise sensitivity (PWS) at the time of fluid detection was compared with 6 and 12 months prior. RESULTS: Fourteen of 161 individuals developed fluid without symptoms. PWS over fluid areas at detection was reduced compared with 6 (difference -2.04 dB, P < 0.001) and 12 months (-2.27 dB, P < 0.001) prior. PWS over fluid areas was reduced compared with perifluid areas (difference -1.02 dB, P = 0.03), peripheral areas (-1.51 dB, P < 0.001), nonprogressed fellow eyes (-1.49 dB, P = 0.006), and nonprogressed age-matched intermediate AMD eyes (-2.29 dB, P = 0.001). No difference in BCVA was observed in eyes developing fluid compared to eyes that do not develop fluid (P = 0.76). CONCLUSIONS: Retinal areas with fluid on SD-OCT had a corresponding reduction in retinal sensitivity at the time of fluid detection compared with 6 and 12 months prior, in asymptomatic intermediate AMD without change in BCVA. TRANSLATIONAL RELEVANCE: Development of self-monitoring tools to detect changes in retinal sensitivity may be helpful for early detection of retinal fluid suggestive of progression to neovascular AMD before acuity is affected.
-
ItemProperties of the Impact of Vision Impairment and Night Vision Questionnaires Among People With Intermediate Age-Related Macular Degeneration(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2019-09)PURPOSE: To explore the psychometric properties of the Impact of Vision Impairment (IVI-28) and Night Vision Questionnaires (NVQ-10) among people with intermediate age-related macular degeneration (iAMD). METHODS: Baseline responses were collected from 288 participants (aged 50-88 years, 74% female) in the Laser intervention in Early stages of Age-related macular Degeneration (LEAD) study in Australia and Northern Ireland. Psychometric properties (discrimination, ordering of thresholds, person separation, item miss-fit, and differential item functioning according to sex) were explored using grouped rating scale and partial credit models. Spearman's correlation was estimated to assess the association with measures of visual function (mean mesopic microperimetric sensitivity, best-corrected visual acuity, low-luminance visual acuity, and low-luminance deficit). The psychometric properties were then explored following recalibration of the instruments. RESULTS: In this homogenous population, ceiling effects caused by relatively high levels of functional vision were evident for both instruments. The IVI-28 and NVQ-10 displayed suboptimal discrimination between levels of functional vision in iAMD and poor targeting among people with iAMD. The correlation between ability scores and measures of visual function was mild. In general, the NVQ-10 showed superior psychometric properties to the IVI-28 among these participants. No significant improvement in reliability could be gained following recalibration. CONCLUSIONS: Both instruments were designed for populations with more severe visual loss and poorly discriminate in this cohort of iAMD. TRANSLATIONAL RELEVANCE: New instruments that can capture the subtle changes in functional vision that occur early in AMD are required to aid evaluation of emerging interventions for iAMD.
-
ItemRelationship Between Rod-Mediated Sensitivity, Low-Luminance Visual Acuity, and Night Vision Questionnaire in Age-Related Macular Degeneration(ASSOC RESEARCH VISION OPHTHALMOLOGY INC, 2020-05)PURPOSE: To quantify the association between dark adaptation parameters and other clinical measures of visual function among people with and without early and intermediate age-related macular degeneration (AMD). METHODS: In this cross-sectional study, participants underwent multimodal imaging and visual function testing, including best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), low-luminance deficit (LLD = BCVA - LLVA) and the 10-item Night Vision Questionnaire (NVQ-10). Dynamic and static dark-adapted chromatic perimetry (DACP) was performed. Sensitivity difference was defined as the difference in sensitivity between the 505-nm and 625-nm stimuli. Rod intercept time (RIT) was estimated as the time required to reach a threshold of -3 log candelas/meter2 with the 505-nm stimulus following bleaching. The magnitude of association between the DACP parameters and other clinical tests was estimated via mixed-effects regression. RESULTS: A total of 51 participants (aged 51-88 years, 65% female, 39% with AMD) were included. RIT was found to be negatively associated with BCVA (P < 0.001), LLVA (P = 0.005), and NVQ-10 score (P = 0.028) but not LLD (P = 0.763). There was no evidence of an association between sensitivity difference and any of the clinical measures (P ≥ 0.081). CONCLUSIONS: Reduced rod function, as determined by RIT, was associated with lower NVQ-10 scores (designed to interrogate rod-mediated function) and with worse BCVA and LLVA (measures of cone function). TRANSLATIONAL RELEVANCE: Decreasing rod function maybe indicative of more generalized photoreceptor dysfunction involving cones. Further development of questionnaires to target function in scotopic conditions may provide an easier to administer test without the need to perform perimetric tests of rod function.