Purchase this article with an account.
V.A. Shah, M. Haeker, M.D. Abramoff, M. Sonka, R. Kardon; Segmental Inner Retinal Layer Analysis of Macular OCT Scan Detects Damage in Unilateral Optic Neuropathy . Invest. Ophthalmol. Vis. Sci. 2006;47(13):1081.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Structural optic nerve damage causing axon loss may be difficult to detect with coexisting optic nerve edema, or other causes of a thickened retinal nerve fiber layer. Layer segmentation of the macular scan by optical coherence tomography (OCT) may help to better define ganglion cell (RGC) loss.
Nine patients with chronic unilateral optic neuropathy were tested by Stratus OCT (circular and macular fast scans) and analyzed by both Stratus algorithm and by a novel segmentation image analysis technique to determine layers of the retina. Boundaries were automatically determined using a graph–based cost function approach that utilized edge/regional image information and a priori–determined constraints. Layer analysis was also performed along the vertical meridian scan at the macula in four patients with altitudinal visual field loss.
Significant differences between the affected and unaffected eyes were found with the cost function layer OCT macular analysis (p=0.013) but not with total retinal thickness (p=0.111). Significant altitudinal differences in macular inner layer thickness (p=0.046) were found in eyes with corresponding field loss. The most significantly affected layer corresponded to the expected location of the RGC. There was significant linear correlation between the Stratus derived retinal layers (retinal nerve fiber layer and total retinal thickness) and our new segmenting algorithm.
The structural information in the layer of the macular OCT scan corresponding to the location of RGC appears to have important potential for assessing optic nerve damage and could be particularly useful when the retinal nerve fiber layer thickness does not correspond to the number of axons, as in case of optic disc edema.
This PDF is available to Subscribers Only