Novel grid combined with peripheral distortion correction for ultra-widefield image grading of age-related macular degeneration

Abstract

PurposeEyes with age-related macular degeneration (AMD) often harbor pathological changes in the retinal periphery and perimacular region. These extramacular changes have not been well classified, but may be phenotypically and functionally relevant. The purpose of this study was to demonstrate a novel grid to systematically study peripheral retinal abnormalities in AMD using geometric distortion-corrected ultra-widefield (UWF) imaging.MethodsThis is a cross-sectional observational case series. Consecutive patients with AMD without any other coexisting vitreoretinal disease and control patients over age 50 without AMD or any other vitreoretinal disease were imaged using Optos 200 Tx. Captured 200° UWF images were corrected for peripheral geometric distortion using Optos transformation software. A newly developed grid to study perimacular and peripheral abnormalities in AMD was then projected onto the images.ResultsPeripheral and perimacular changes such as drusen, retinal pigment epithelium changes and atrophy were found in patients with AMD. The presented grid in conjunction with geometric distortion-corrected UWF images allowed for systematic study of these peripheral changes in AMD.ConclusionWe present a novel grid to study peripheral and posterior pole changes in AMD. The grid is unique in that it adds a perimacular zone, which may be important in characterizing certain phenotypes in AMD. Our UWF images were corrected for geometric peripheral distortion to accurately reflect the anatomical dimensions of the retina. This grid offers a reliable and reproducible foundation for the exploration of peripheral retinal pathology associated with AMD.

Evaluation of Peripheral Retinal Changes on Ultra-widefield Fundus Autofluorescence Images of Patients with Age-related Macular Degeneration

“…8 Since more standard images were obtained in published studies that utilized the software developed by Optos to eliminate torsion in images obtained in the upward and downward gaze fixation positions of the device, these studies seem to have less subjectivity. 4,9 In the present study, we evaluated images taken without using such software separately. In future studies, it may be beneficial to use software that ensures standardization in order to prevent analytical errors that may result from subjective evaluation.…”

“…Studies conducted to date present different views regarding how the midperipheral area (i.e., the retinal region referred to as zone 2) should be calculated. 4,5,7,8,9,10,11,12 When planning the present study, we accepted an area of 3 DD as zone 1 and an area of 9 DD as zone 2 (considered the midperiphery). 5,6 Confusion regarding the definition of the midperipheral region in the literature is preventing its standardization in current studies and necessitates the establishment of standard measurements which can be incorporated into emerging technologies.…”

Ultra-wide-field imaging of choroidal melanoma before and after proton beam radiation therapy

“…Each channel was viewed separately and analysed with the Optomap Vantage V2 Software with ProView™ option, which minimises distortion and magnification irregularities. 16 The following data were evaluated (pre-treatment and at the last follow-up visit): Snellen visual acuity (hand perception was noted as 20/2000), tumour location as well as post PBRT retinopathy (telangiectasias, microaneurysms, neovascularisation, vitreous haemorrhage, hard exudates, cotton wool spots, retinal edema) ( Figure 1); maculopathy (macular edema); optic neuropathy (pale optic disc, disc edema along with haemorrhage and microangiopathy); and toxic tumour syndrome (all of the above plus exudative retinal detachment and/or rubeosis iridis and neovascular glaucoma). 4 A number of parameters on the Optos images were documented (Table 1).…”

Ultra‐widefield fundus photography for radiation therapy planning of ocular tumours

“…; Oellers et al. ). However, the effects of distortion have not yet been assessed in ocular oncology clinical practice.…”

“…A narrow-field view, as obtained with standard fundus photography (SF), needs a reconstructed montage using multiple narrow-field fundus photography to visualize the outer borders of large tumours and those located at the periphery (Kim et al 2009). This limitation can be overcome with UWF, but as the 3D spherical eye is converted to a 2D image distortion could potentially be a problem for UWF devices that cover a larger part of the fundus (Doelemeyer & Petrig 2000;Lee et al 2007;Nicholson et al 2018), and it has previously been shown that while distortion is minimal near the posterior pole of the eye and increases as the peripheral retina is approached (Daftari et al 2010;Oellers et al 2017). However, the effects of distortion have not yet been assessed in ocular oncology clinical practice.…”