ORCID Profile
0000-0003-1339-4099
Current Organisations
University College London
,
Singapore National Eye Centre
,
University of Oxford
,
University of Cambridge
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Publisher: BMJ
Date: 04-10-2020
DOI: 10.1136/BJOPHTHALMOL-2019-314706
Abstract: To assess the agreement in measuring retinal nerve fibre layer (RNFL) thickness between spectral-domain (SD Cirrus HD, Carl Zeiss Meditec, USA) optical coherence tomography (OCT) and swept-source (SS Plex Elite 9000, Carl Zeiss Meditec) OCT using an OCT angiography (OCTA) scanning protocol. 57 participants (12 glaucomatous, 8 ocular hypertensive and 74 normal eyes) were scanned with two OCT instruments by a single experienced operator on the same day. Circumpapillary RNFL thicknesses were automatically segmented for SD-OCT and manually segmented for SS-OCTA scans. Agreement of global RNFL thickness, as well as average thickness in four quadrants was assessed using intraclass correlation coefficients (ICCs). There was excellent agreement in the inferior and superior quadrants and the global (all ICC .90), followed by good agreement in the temporal (ICC=0.79) and nasal (ICC=0.73) quadrants. The ICC values were similar in the subgroups except within the ocular hypertension group, where the nasal quadrant was less agreeable (ICC=0.31). SS-OCTA-derived RNFL thickness was on average 3 µm thicker than SD-OCT, particularly in the nasal (69.7±11.5 µm vs 66.3±9.3 µm p .001) and temporal (75.6±13.7 µm vs 67.9±12.3 µm p .001) quadrants. RNFL measurements taken with SS-OCTA have good-to-excellent agreement with SD-OCT, which suggests that the RNFL thickness can be sufficiently extracted from wide-field OCTA scans.
Publisher: BMJ
Date: 05-05-2020
DOI: 10.1136/BJOPHTHALMOL-2020-315985
Abstract: To identify factors that influence the diagnostic performance of circumpapillary retinal nerve fibre layer (RNFL) thickness measurements in the detection of primary open-angle glaucoma (POAG). 1592 eyes from 1076 healthy controls and 758 eyes from 502 patients with POAG underwent optical coherence tomography (OCT) imaging to assess RNFL parameters. Visual field (VF) mean deviation (MD) from standard automated perimetry was used to indicate severity in subjects with glaucoma. RNFL thickness significantly decreased with age (ρ=−0.10 to −0.16, p .001) and increased with spherical equivalent (SE) refractive error (ρ=0.23–0.29, p .001) in healthy and glaucoma groups but showed a significant reduction with SE (ρ=−0.20, p .001) in the temporal RNFL of healthy subjects. RNFL measurements significantly decreased with VF MD (ρ=0.08–0.53, p .05) in subjects with POAG. When healthy subjects and subjects with glaucoma were matched to subgroups within a factor, significant differences in area under the curve (AUC) between subgroups were only found with SE AUCs increased significantly with disease severity, particularly in the global, inferior and superior measurements (p .001). Overall, the diagnostic performance of the inferior and global RNFL measurements were found to be more resilient to different factors. Diagnostic accuracy in glaucoma was influenced by SE but could be mitigated by using controls with similar refractive characteristics. Increasing disease severity led to significantly better diagnostic accuracy. These factors should be considered when using OCT for glaucoma diagnosis in practice.
Publisher: Springer Science and Business Media LLC
Date: 18-02-2020
DOI: 10.1038/S41598-020-59792-9
Abstract: We evaluated the changes in visual field mean deviation (VF MD) and retinal nerve fibre layer (RNFL) thickness in glaucoma patients undergoing trabeculectomy. One hundred patients were examined with VF and spectral-domain optical coherence tomography (OCT) before trabeculectomy and 4 follow-up visits over one year. Linear mixed models were used to investigate factors associated with VF and RNFL. VF improved during the first 3 months of follow-up (2.55 ± 1.06 dB/year) and worsened at later visits (−1.14 ± 0.29 dB/year). RNFL thickness reduced by −4.21 ± 0.25 µm/year from 1st month of follow-up. Eyes with an absence of initial VF improvement (β = 0.64 0.30–0.98), RNFL thinning (β = 0.15 0.08–0.23), increasing intraocular pressure (IOP β = −0.11 −0.18 to −0.03) and severe glaucoma (β = −10.82 −13.61 to −8.02) were associated with VF deterioration. Eyes with VF deterioration (β = 0.19 0.08–0.29), increasing IOP (β = −0.09 −0.17 to −0.01), and moderate (β = −6.33 −12.17 to −0.49) or severe glaucoma (β = −19.58 −24.63 to −14.52) were associated with RNFL thinning. Changes in RNFL structure and function occur over a 1-year follow-up period after trabeculectomy. Early VF improvement is more likely to occur in patients with mild/moderate glaucoma, whereas those with severe glaucoma show greater decline over one year. Our findings indicate that progression is observable using OCT, even in late-stage glaucoma.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Rachel Chong.