RPE Curvature Can Screen for Early and Intermediate AMD.

Purpose: Diagnosing AMD early optimizes clinical management. However, current diagnostic accuracy is limited by the subjectivity of qualitative diagnostic measures used in clinical practice. This study tests if RPE curvature could be an accurate, quantitative measure for AMD diagnosis. Methods: Consecutive patients without AMD or normal aging changes (n = 111), with normal aging changes (n = 107), early AMD (n = 102) and intermediate AMD (n = 114) were recruited. RPE curvature was calculated based on the sinuosity method of measuring river curvature in environmental science. RPE and Bruch's membrane were manually segmented from optical coherence tomography B-scans and then their lengths automatically extracted using customized MATLAB code. RPE sinuosity was calculated as a ratio of RPE to Bruch's membrane length. Diagnostic accuracy was determined from area under the receiver operator characteristic curve (aROC). Results: RPE sinuosity of foveal B-scans could distinguish any eyes with AMD (early or intermediate) from those without AMD (non-AMD or eyes with normal aging changes) with acceptable diagnostic accuracy (aROC = 0.775). Similarly, RPE sinuosity could identify intermediate AMD from all other groups (aROC = 0.871) and distinguish between early and intermediate AMD (aROC = 0.737). RPE sinuosity was significantly associated with known AMD lesions: reticular pseudodrusen (P < 0.0001) and drusen volume (P < 0.0001), but not physiological variables such as age, sex, and ethnicity. Conclusions: RPE sinuosity is a simple, robust, quantitative biomarker that is amenable to automation and could enhance screening of AMD.

Evaluating the clinical relevance and reliability of outer retinal band length on optical coherence tomography in retinal disease: a cross-sectional study.

OBJECTIVES: Hyper-reflective outer retinal band (HORB) disruptions are reported across a range of retinal disease, yet a reliable, easily implemented assessment method and thorough evaluation of their association to retinal disease is lacking. The purpose of the study was to assess the reliability of using magnitude estimation to evaluate HORB length and determine its association to visual acuity and retinal disease. DESIGN: Cross-sectional, retrospective study. SETTING: Patients attending a secondary eye care clinic in Sydney, Australia. PARTICIPANTS: 2039 unique consecutive patients were screened for inclusion between 2 November and 18 January 2021, and 600 were included in the study population. Patients were included if they were referred from primary care, presented for an initial, comprehensive eye examination during the study period, imaged with optical coherence tomography during their visit and over 18 years of age. PRIMARY OUTCOME: Reliability of HORB length estimations and associations to clinical outcomes. RESULTS: Intragrader (intraclass correlation coefficient, ICCfovea=0.81; ICCworst=0.91) and intergrader (ICCfovea=0.78-0.79; ICCworst=0.75-0.88) agreement of HORB length was good to excellent. HORB length was significantly associated with age (p<0.001, ß=-0.22 to -0.24) and refractive error (p<0.001, ß=0.12-0.16) at all B-scan locations. Visual acuity (p=0.001, ß=-0.13) was associated with the primary outcome for foveal B-scans and eccentricity (p=0.002, ß=-0.13) and device type (p=0.002, ß=0.13) for non-foveal B-scans. Glaucoma was associated with HORB length on univariate analysis (p=0.05-0.06, ß=-0.08); however, multivariate analysis revealed no significant association between HORB length and retinal disease. CONCLUSION: HORB length is reliably assessed using magnitude estimation and may be useful as a surrogate biomarker of visual acuity. Several factors affect HORB length estimations, which may contribute to the lack of association to retinal disease and highlights the need for covariable adjustment when examining HORB disruptions.

OCT Prognostic Biomarkers for Progression to Late Age-related Macular Degeneration: A Systematic Review and Meta-analysis.

TOPIC: To evaluate which OCT prognostic biomarkers best predict the risk of progression from early/intermediate to late age-related macular degeneration (AMD). CLINICAL RELEVANCE: Among > 100 OCT prognostic biomarkers for AMD, it is unclear which are the most relevant for clinicians and researchers to focus on. This review evaluated which OCT biomarkers confer the greatest magnitude of prediction for progression to late AMD. METHODS: Study protocol was registered on PROSPERO (CRD42023400166). PubMed and Embase were searched from inception to March 2, 2023, and eligible studies assessed following the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The primary outcome was any quantified risk of progression from treatment-naive early/intermediate AMD to late AMD, including hazard ratios (HRs), odds ratios (ORs), and standardized mean differences (at baseline, between eyes with versus without progression), subgrouped by each OCT biomarker. Further meta-analyses were subgrouped by progression to geographic atrophy or neovascularization. RESULTS: A total of 114 quantified OCT prognostic biomarkers were identified. With high GRADE certainty of evidence, the greatest magnitudes of prediction to late AMD belonged to: external limiting membrane abnormality (OR, 15.42 [7.63, 31.17]), ellipsoid zone abnormality (OR, 10.8 [4.58, 25.46]), interdigitation zone abnormality (OR, 7.68 [2.57, 23]), concurrent large drusen and reticular pseudodrusen (HR, 6.73 [1.35, 33.65], hyporeflective drusen cores (HR, 2.48 [1.8, 3.4]; OR 1.85 [1.29, 2.66]), intraretinal hyperreflective foci (IHRF; HR, 2.16 [0.92, 5.07]; OR 5.08 [3.26, 7.92]), and large drusen (HR, 2.01 [1.35, 2.99]); OR, 1.98 [1.27, 3.08]). There was greater risk of geographic atrophy for IHRF and hyporeflective drusen cores (P < 0.05), and neovascularization for ellipsoid zone abnormality (P < 0.05). Other OCT biomarkers such as drusenoid pigment epithelium detachment, shallow irregular retinal pigment epithelium elevations, and nascent geographic atrophy exhibited large magnitudes of risk but required further studies for validation. CONCLUSION: This review synthesizes the 6 most relevant OCT prognostic biomarkers for AMD with greater predictive ability than large drusen alone, for clinicians and researchers to focus on. Further study is required to validate other biomarkers with less than high certainty of evidence, and assess how the copresence of biomarkers may affect risks. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Optometrists' attitudes toward using OCT angiography lag behind other retinal imaging types.

PURPOSE: While optometrists' attitudes toward established retinal imaging types are generally positive, they are unknown for optical coherence tomography angiography (OCTA). We performed a cross-sectional survey to estimate attitudes toward OCTA and identify clinician and/or practice characteristics that influence them. METHODS: A paper-based survey was mailed to 252 randomly selected optometrists in Australia. Five-point Likert-scale items from a previous survey assessing attitudes toward new technology were included to probe respondent characteristics and attitudes toward retinal imaging. Performance expectancy attitudes toward OCTA were elicited by the statement 'I believe OCTA is useful in daily practice'. Mean scores out of five (mean [SD]) were rounded and mapped to appropriate descriptive statements. RESULTS: The response rate was 47% (118/252). The mean (SD) age of respondents was 44.0 (13.8) years and 50.8% (60/118) were female. Optometrists had 19.9 (14.0) years of clinical experience and 66.9% (79/118) worked at independent practices. In total, 8.5% (10/118) of respondents used OCTA to provide clinical care. Optometrists agreed that optical coherence tomography (OCT), colour fundus imaging, ultra-wide field imaging and fundus autofluorescence (mean scores 3.6-4.7 out of 5) were useful in daily practice but felt neutral about whether OCTA was useful (3.4 [0.8]). Optometrists believed that OCTA was less enjoyable to use (p < 0.0001), less endorsed by peers (p < 0.0001) and felt less confident that they had the knowledge to interpret OCTA (p < 0.0001) compared to other retinal imaging types. CONCLUSIONS: Optometrists are undecided on whether OCTA is useful in daily practice and had lower expectations that using OCTA would confer job performance benefits compared to other retinal imaging types. Further work is needed to advocate the benefits of using OCTA across the profession.

Visualisation of peripheral retinal degenerations and anomalies with ocular imaging.

PURPOSE: Certain peripheral retinal degenerations pose a significant risk to vision and require prompt detection and management. Other historically "benign" peripheral lesions are being recognised as clinically significant due to their associations with ocular and systemic disorders. Assessment and documentation of these entities however can be difficult due to challenges in visualisation of the peripheral retina. This review addresses this by providing a series of clinical examples of these entities visualised with a variety of ocular imaging technologies. METHODS: A literature search was performed in Embase, Medline, and Google Scholar. We identified and analysed all papers referring to peripheral retinal degenerations and the peripheral retina, as well as reference lists of retrieved articles until August 2019. RESULTS: Using ocular imaging technologies including ultra-widefield imaging and peripheral optical coherence tomography, we comprehensively describe current evidence and knowledge of a number of peripheral retinal degenerations and anomalies including microcystoid, pavingstone, lattice, snail track, snowflake and reticular pigmentary degenerations, peripheral drusen, white without pressure, retinal holes and vitreoretinal tufts. A summary of these entities is also provided as a short and easily interpretable chairside guide to facilitate the translation of this evidence base into clinical practice. CONCLUSION: While ocular technologies are useful in visualising peripheral retinal degenerations, the current evidence is fragmented throughout the literature and there is a paucity of information on imaging of "benign" peripheral lesions. This review facilitates a multimodal imaging approach to evaluating peripheral lesions.

Viewing distance and eyestrain symptoms with prolonged viewing of smartphones.

BACKGROUND: This paper investigates viewing distances and eyestrain symptoms in young adults reading from a smartphone for 60 minutes. METHODS: A survey related to common asthenopic (eyestrain) symptoms was administered to subjects before and after they read an extract from a novel on a smartphone for 60 minutes. Subjects rated their symptoms on a scale from zero (not at all) to four (extremely). The viewing distance to the smartphone was measured on a photograph taken of the subject every minute. Each subject used the same smartphone and read the same text. RESULTS: Subjects were 18 young adults (mean age: 21.5 ± 3.3 years) with self-reported good health, normal visual acuity and no accommodative or binocular vision disorders. The mean viewing distance while using a smartphone over 60 minutes was 29.2 ± 7.3 cm. The viewing distance was significantly greater during the first, second and fifth 10-minute time periods (30.6 ± 7.2 cm, 29.7 ± 7.3 cm and 28.9 ± 8.5 cm, respectively) than during the final 10-minute time period (27.8 ± 7.7 cm) (Wilcoxon, p = 0.023, 0.02 and 0.04, respectively). The total symptom score was significantly greater post-experiment (score = 8.06) than pre-experiment (score = 3.56) (Wilcoxon, p < 0.001). Symptoms of tired eyes, uncomfortable eyes and blur increased significantly after 60 minutes of smartphone use (Wilcoxon, p < 0.05). There was a significant correlation between change in total symptom score and change in viewing distance (ρ = -0.51; p = 0.03). The only single symptom that correlated with a change in viewing distance was 'uncomfortable eyes' (ρ = -0.52, p = 0.03). CONCLUSION: Viewing distances are closer and eyestrain symptoms are greater after reading from a smartphone for 60 minutes. The viewing distances measured were closer than those previously reported in the literature.