Comparison of Geographic Atrophy Measurements from the OCT Fundus Image and the Sub-RPE Slab Image

Abstract

PURPOSE: To compare two different approaches to measuring areas of geographic atrophy (GA) using spectral-domain optical coherence tomography (SD-OCT). METHODS: Fifty eyes with GA were imaged with an SD-OCT instrument. OCT fundus images and sub– retinal pigment epithelium (RPE) slab images were generated. Three graders manually drew the GA boundaries on both en face images. An automated algorithm was used to segment the GA boundaries from the sub-RPE slabs. RESULTS: The agreement between the three manual measurements on both OCT fundus images (ICC = .998) and sub-RPE slabs (ICC = .999) was excellent. Area measurements from OCT fundus images and sub-RPE slabs were highly correlated. The agreement between manual and automated measurements on the sub-RPE slabs was very good (ICC = .795). CONCLUSION: Both OCT fundus images and sub-RPE slab images proved useful for measuring GA in age-related macular degeneration. The automated algorithm typically provided useful measurements of GA area from the sub-RPE slabs. [ Ophthalmic Surg Lasers Imaging Retina . 2013;44:127–132]

Drusen and RPE atrophy automated quantification by optical coherence tomography in an elderly population

“…Automated algorithms to segment the OCT images accurately and Eye reproducibly have been described, [13][14][15][16] and, importantly, have now become available in commercial devices. In the present study, we demonstrate that these algorithms may be used to study and describe drusen and RA burden in a population-based study of elderly patients.…”

“…This algorithm, which has been recently validated by comparison with manual segmentation, 15,16 uses the RPE geometry and compares this segmentation map with a virtual map of the RPE free of deformations (RPE floor) ( Figure 1). Using these two maps, the algorithm creates an elevation map that permits measurement of drusen area and volume.…”

“…Quantification of drusen and RA has been demonstrated with both manual and automated strategies, 14 and recently automated quantification techniques have become available in commercial SD-OCT (Carl Zeiss Meditec Inc, Dublin, CA, USA) software. Validation of the accuracy and reproducibility 13,15,16 of these fully automated algorithms has created an opportunity to study AMD lesions in population studies. 17 To our knowledge, the epidemiologic features of AMD have not previously been associated with automated OCT quantification data.…”

Change in Drusen Volume as a Novel Clinical Trial Endpoint for the Study of Complement Inhibition in Age-related Macular Degeneration

“…The same scan pattern was used to generate the OCT fundus image (OFI) and the sub-RPE slab OFIs. 34,35 These images were used to assess the development of GA during the follow-up visits. Autofluorescence and fluorescein angiography images were used as well to assess the formation of GA. Fluorescein angiography and SD-OCT imaging were used to assess the formation of macular neovascularization.…”

Automatic versus Manual Segmentation of Choroidal Neovascularization Lesions Using Optical Coherence Tomography

“…However, Spectral Domain-OCT (SD-OCT) systems integrated newer technology and improved segmentation software, allowing for improved imageanalysis, including subretinal hyper reflective material (SHRM), and evaluation of pathology [19][20][21][22]. In addition to segmentation software, SD-OCT systems are integrated with analysis software designed to automatically detect deviations from the RPE contour and quantify their surface area and volume [23][24][25][26][27][28][29]. Assuming classic CNV lesions form half-ellipsoid shapes; one can use such tools with automatic segmentation software in serial imaging to monitor nAMD disease progression and response to therapy ( Figure 2) [30][31][32].…”