PurposeTo investigate repeatability and reproducibility of thickness of eight individual retinal layers at axial and lateral foveal locations, as well as foveal width, measured from Spectralis spectral domain optical coherence tomography (SD-OCT) scans using newly available retinal layer segmentation software.MethodsHigh-resolution SD-OCT scans were acquired for 40 eyes of 40 young healthy volunteers. Two scans were obtained in a single visit for each participant. Using new Spectralis segmentation software, two investigators independently obtained thickness of each of eight individual retinal layers at 0°, 2° and 5° eccentricities nasal and temporal to foveal centre, as well as foveal width measurements. Bland-Altman Coefficient of Repeatability (CoR) was calculated for inter-investigator and inter-scan agreement of all retinal measurements. Spearman's ρ indicated correlation of manually located central retinal thickness (RT0) with automated minimum foveal thickness (MFT) measurements. In addition, we investigated nasal-temporal symmetry of individual retinal layer thickness within the foveal pit.ResultsInter-scan CoR values ranged from 3.1μm for axial retinal nerve fibre layer thickness to 15.0μm for the ganglion cell layer at 5° eccentricity. Mean foveal width was 2550μm ± 322μm with a CoR of 13μm for inter-investigator and 40μm for inter-scan agreement. Correlation of RT0 and MFT was very good (ρ = 0.97, P < 0.0005). There were no significant differences in thickness of any individual retinal layers at 2° nasal compared to temporal to fovea (P > 0.05); however this symmetry could not be found at 5° eccentricity.ConclusionsWe demonstrate excellent repeatability and reproducibility of each of eight individual retinal layer thickness measurements within the fovea as well as foveal width using Spectralis SD-OCT segmentation software in a young, healthy cohort. Thickness of all individual retinal layers were symmetrical at 2°, but not at 5° eccentricity away from the fovea.

Purpose: Outdoor light exposure is considered a safe and effective strategy to reduce myopia development and aligns with existing public health initiatives to promote healthier lifestyles in children. However, it is unclear whether this strategy reduces myopia progression in eyes that are already myopic. This study aims to conduct an overview of systematic reviews (SRs) reporting time spent outdoors as a strategy to prevent myopia or slow its progression in children. Methods:We searched the Cochrane Library, EMBASE, MEDLINE and CINAHL from inception to 1 November 2020 to identify SRs that evaluated the association between outdoor light exposure and myopia development or progression in children. Outcomes included incident myopia, prevalent myopia and change in spherical equivalent refraction (SER) and axial length (AL) to evaluate annual rates of myopia progression. The methodological quality and risk of bias of included SRs were assessed using the AMSTAR-2 and ROBIS tools, respectively.Results: Seven SRs were identified, which included data from 47 primary studies with 63,920 participants. Pooled estimates (risk or odds ratios) consistently demonstrated that time outdoors was associated with a reduction in prevalence and incidence of myopia. In terms of slowing progression in eyes that were already myopic, the reported annual reductions in SER and AL from baseline were small (0.13-0.17 D) and regarded as clinically insignificant. Methodological quality assessment using AMSTAR-2 found that all reviews had one or more critical flaws and the ROBIS tool identified a low risk of bias in only two of the included SRs. Conclusion:This overview found that increased exposure to outdoor light reduces myopia development. However, based on annual change in SER and AL, there is insufficient evidence for a clinically significant effect on myopia progression. The poor methodological quality and inconsistent reporting of the included systematic reviews reduce confidence in the estimates of effect.

It can take several years to become proficient at direct ophthalmoscopy; the instrument’s single eyepiece allows only one individual to view the image at a time, which is considered disadvantageous during teaching. The introduction of smartphone ophthalmoscopes enables groups of teachers and students to view images together which could encourage peer-to-peer learning. In addition, the technology is significantly cheaper than the direct ophthalmoscope. User acceptability and engagement is essential to the success of any (medical) technological innovation. We sought to understand student opinions of a new commercially-available smartphone device for fundus examination, and compare usability to the traditional ophthalmoscope, from the perspective of both student practitioners and patients. Fifty-four undergraduate optometry students with prior experience of the traditional direct ophthalmoscope were asked to examine at least one eye with the D-EYE smartphone ophthalmoscope and also given an opportunity to experience the D-EYE from a patient’s perspective. Minimal instructions were provided and all examinations conducted through undilated pupils. Participants completed an opinion survey to feedback on aspects such as the ease of handling and working distance. Compared to the direct ophthalmoscope, 92% of students preferred the (longer) working distance of the D-EYE; 77% felt it was easier to handle; and 92% preferred the patient experience with the D-EYE. Despite the positive feedback, only 43% of students preferred the D-EYE when assuming the role of the practitioner. Free text responses indicated that students felt the D-EYE may be most useful as a teaching tool. Student opinions indicated that smartphone ophthalmoscopes are an effective training tool for students as an accompaniment to learning the traditional ophthalmoscope method.

This is the accepted version of the paper.This version of the publication may differ from the final published version. The final publication is available at http://link.springer.com/article/10.1007/s00417-014-2915-9 2 Permanent repository link Abstract (180 words) 22Purpose: To assess the effects of incorporating individual ocular biometry 23 measures of corneal curvature, refractive error and axial length on scan 24 length obtained using Spectralis spectral domain optical coherence 25 tomography (SD-OCT). 26Methods: Two SD-OCT scans were acquired for 50 eyes of 50 healthy 27 participants, first using the Spectralis default keratometry (K) setting, then 28 incorporating individual mean-K values. Resulting scan lengths were 29 compared to predicted scan lengths produced by image simulation software 30 based on individual ocular biometry measures including axial length. 31Results: Axial length varied from 21.41 to 29.04mm. Spectralis SD-OCT scan 32 lengths obtained with default-K ranged from 5.7 to 7.3mm and with mean-K 33 5.6 to 7.6mm. We report a stronger correlation of simulated scan lengths 34 incorporating the subject's mean-K value (ρ = 0.926, P < 0.0005) compared to 35 Spectralis default settings (ρ = 0.663, P < 0.0005). 36Conclusions: Ocular magnification appears to be better accounted for when 37 individual mean-K values are incorporated into Spectralis SD-OCT scan 38 acquisition compared to using the device's default-K setting. This must be 39 considered when taking area measurements and lateral measurements 40 parallel to the retinal surface. 41 42

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