by Croft, DE, van Hemert, J, Wykoff, CC, Clifton, D, Verhoek, M, Fleming, A and Brown, DM
Abstract:
BACKGROUND AND OBJECTIVE: Accurate quantification of retinal surface area from ultra-widefield (UWF) images is challenging due to warping produced when the retina is projected onto a two-dimensional plane for analysis. By accounting for this, the authors sought to precisely montage and accurately quantify retinal surface area in square millimeters. PATIENTS AND METHODS: Montages were created using Optos 200Tx (Optos, Dunfermline, UK) images taken at different gaze angles. A transformation projected the images to their correct location on a three-dimensional model. Area was quantified with spherical trigonometry. Warping, precision, and accuracy were assessed. RESULTS: Uncorrected, posterior pixels represented up to 79% greater surface area than peripheral pixels. Assessing precision, a standard region was quantified across 10 montages of the same eye (RSD: 0.7%; mean: 408.97 mm(2); range: 405.34-413.87 mm(2)). Assessing accuracy, 50 patients' disc areas were quantified (mean: 2.21 mm(2); SE: 0.06 mm(2)), and the results fell within the normative range. CONCLUSION: By accounting for warping inherent in UWF images, precise montaging and accurate quantification of retinal surface area in square millimeters were achieved. [Ophthalmic Surg Lasers Imaging Retina. 2014;45:312-7.].
Reference:
Precise montaging and metric quantification of retinal surface area from ultra-widefield fundus photography and fluorescein angiography. (Croft, DE, van Hemert, J, Wykoff, CC, Clifton, D, Verhoek, M, Fleming, A and Brown, DM), In Ophthalmic Surg Lasers Imaging Retina, volume 45, 2014.
Bibtex Entry:
@article{CroftHemert2014fk,
abstract = {BACKGROUND AND OBJECTIVE: Accurate quantification of retinal surface area from ultra-widefield (UWF) images is challenging due to warping produced when the retina is projected onto a two-dimensional plane for analysis. By accounting for this, the authors sought to precisely montage and accurately quantify retinal surface area in square millimeters. PATIENTS AND METHODS: Montages were created using Optos 200Tx (Optos, Dunfermline, UK) images taken at different gaze angles. A transformation projected the images to their correct location on a three-dimensional model. Area was quantified with spherical trigonometry. Warping, precision, and accuracy were assessed. RESULTS: Uncorrected, posterior pixels represented up to 79% greater surface area than peripheral pixels. Assessing precision, a standard region was quantified across 10 montages of the same eye (RSD: 0.7%; mean: 408.97 mm(2); range: 405.34-413.87 mm(2)). Assessing accuracy, 50 patients' disc areas were quantified (mean: 2.21 mm(2); SE: 0.06 mm(2)), and the results fell within the normative range. CONCLUSION: By accounting for warping inherent in UWF images, precise montaging and accurate quantification of retinal surface area in square millimeters were achieved. [Ophthalmic Surg Lasers Imaging Retina. 2014;45:312-7.].},
author = {Croft, DE and van Hemert, J and Wykoff, CC and Clifton, D and Verhoek, M and Fleming, A and Brown, DM},
date-added = {2014-07-22 17:23:44 +0000},
date-modified = {2014-07-22 17:24:25 +0000},
doi = {10.3928/23258160-20140709-07},
issn = {2325-8179 (Electronic)},
journal = {Ophthalmic Surg Lasers Imaging Retina},
keywords = {retinal imaging; medical},
number = {4},
pages = {312--7},
title = {Precise montaging and metric quantification of retinal surface area from ultra-widefield fundus photography and fluorescein angiography.},
volume = {45},
year = {2014},
bdsk-url-1 = {http://dx.doi.org/10.3928/23258160-20140709-07}}