In Vivo Imaging of Lamina Cribrosa Pores by Adaptive Optics Scanning Laser Ophthalmoscopy
ABSTRACT To visualize and assess the surface-level pores of the lamina cribrosa in patients with glaucoma by using a prototype adaptive optics scanning laser ophthalmoscopy (AOSLO) system.
The numbers of laminar pores were compared between color disc photography, scanning laser ophthalmoscopy (SLO) without AO, and AOSLO. The pore area and elongation index were examined for correlation with ocular parameters such as the mean deviation, disc area, cup/disc ratio, disc ovality index, intraocular pressure (IOP), and axial length in the AOSLO images.
The 40 eyes (20 normal and 20 glaucomatous) of 40 subjects were enrolled. The AOSLO provided laminar pore images of better quality than other imaging methods, and the number of visible pores was significantly greater in the AOSLO images than in the other imaging methods (the color disc photographs [P < 0.001] and SLO without AO images [P < 0.001]) when compared for 26 subjects. When compared for 40 subjects using AOSLO, the pore area was significantly larger in glaucomatous subjects than in normal subjects (P = 0.031), but elongation index was not. The pore area correlated significantly with the axial length (P = 0.008) in normal subjects, with the untreated IOPs (P = 0.002) in the glaucomatous subjects, and with the axial length (P = 0.001) and cup/disc ratio (P = 0.012) in the total subjects. Via multiple regression analysis, significant correlations with pore area were found for axial length in the normal (β = 0.684, P = 0.001) and total subjects (β = 0.496, P < 0.001) and untreated IOP in the glaucomatous (β = 0.506, P = 0.023) and total subjects (β = 0.331, P = 0.014).
AOSLO is a useful imaging technology for assessing laminar pore morphology. The laminar pore area may be affected by axial length and IOP.
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ABSTRACT: Purpose: To better understand the nature of glaucomatous damage of the macula, especially the structural changes seen between relatively healthy and clearly abnormal retinal regions, using an adaptive optics scanning light ophthalmoscope (AO-SLO). Methods: AO-SLO images and optical coherence tomography (OCT) vertical line scans were obtained on one eye of 7 glaucoma patients, with relatively deep local arcuate defects on the 10-2 visual field test in one (6 eyes) or both hemifields (1 eye). Based upon the OCT images, the retinal nerve fiber (RNF) layer was divided into two regions: 1. Within normal limits (WNL): relative RNF layer thickness within mean control values ±2SD and 2. Abnormal (AB): relative thickness less than -2SD value. Results: As seen on AO-SLO, the pattern of abnormal RNF bundles near the border of the WNL and AB regions differed across eyes. There were normal-appearing bundles in the WNL region of all eyes and abnormal-appearing bundles near the border with the AB region. This region with abnormal bundles ranged in extent from a few bundles to the entire AB region in the case of one eye. All other eyes had a large AB region without bundles. However, in 2 of these eyes, a few bundles were seen within this region of otherwise missing bundles. Conclusions: The AO-SLO images revealed details of glaucomatous damage that are difficult, if not impossible, to see with current OCT technology. AO-SLO may prove useful in following progression in clinical trials, or in disease management if AO-SLO becomes widely available and easy to use. Copyright © 2015 by Association for Research in Vision and Ophthalmology.Investigative Ophthalmology & Visual Science 01/2015; 56(1). DOI:10.1167/iovs.14-15936 · 3.66 Impact Factor
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ABSTRACT: The lamina cribrosa is the putative site of retinal ganglion cell axonal injury in glaucoma. Although histological studies have provided evidence of structural changes to the lamina cribrosa, even in early stages of glaucoma, until recently, the ability to evaluate the lamina cribrosa in vivo has been limited. Recent advances in optical coherence tomography, including enhanced depth and swept-source imaging, have changed this, providing a means to image the lamina cribrosa. Imaging has identified general and localized configurational changes in the lamina of glaucomatous eyes, including posterior laminar displacement, altered laminar thickness, and focal laminar defects with spatial association with conventional structural and functional losses. In addition, although the temporal relationship between changes to the lamina cribrosa and glaucomatous retinal ganglion cell loss is yet to be elucidated, quantitative measurements of laminar microarchitecture have good reproducibility and offer the potential to serve as biomarkers for glaucoma diagnosis and progression.04/2015; DOI:10.1007/s40135-015-0067-7
Dataset: Shoji T Graefe 2014 online