Optic Disc Morphology in Open-Angle Glaucoma Compared with Anterior Ischemic Optic Neuropathies (original) (raw)
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Changes in the Optic Disc after Acute Primary Angle Closure
Ophthalmology, 2006
To evaluate the changes in optic disc morphology in the first 4 months after an episode of acute primary angle closure (APAC) using stereoscopic optic disc photography and computer-assisted planimetry. Prospective observational case series. Forty-seven Asian subjects with unilateral APAC who were successfully treated with laser peripheral iridotomy (LPI). Cup-to-disc ratio (CDR) and optic cup and neuroretinal rim areas. Stereoscopic optic disc photographs were taken 2 and 16 weeks after LPI, and the images were analyzed by computer-assisted planimetry. The overall, quadrantic, and 30 degrees sector areas of the optic disc, CDR, and neuroretinal rim area were analyzed by 2 independent masked graders, and the mean of the readings was used to calculate changes in optic disc parameters. The majority of the subjects were female (66%) and Chinese (90%), and the mean age was 67.6+/-11.2 years (range, 40-94). In APAC eyes from week 2 to week 16, the mean CDR increased from 0.56+/-0.05 to 0.59+/-0.03 (P<0.001), and the mean neuroretinal rim area decreased from 1.74+/-0.31 mm2 to 1.59+/-0.27 mm2 (P<0.001). Quadrantic and sector analysis showed preferential loss of neuroretinal rim area at the superotemporal and inferotemporal areas. There was no significant change in optic disc parameters in the fellow eyes over the study period. This study demonstrated changes in optic disc morphology from week 2 to week 16 after an episode of APAC. The pattern of optic nerve damage demonstrated in our study was comparable with that seen in primary open-angle glaucoma and experimental glaucoma models.
Ophthalmology, 2006
To evaluate the results of scanning laser tomography and scanning laser polarimetry (SLP) and the correlations with visual field damage (VFD) in eyes with nonarteritic ischemic optic neuropathy (n-AION) compared with eyes with open-angle glaucoma (OAG). Cross-sectional study. Thirty-three eyes of 33 patients with n-AION and 33 eyes with OAG whose age and VFD evaluated with the Humphrey field analyzer were matched to those of the n-AION eyes. The parameters of optic disc topography obtained with the Heidelberg Retina Tomograph II (HRT II) and retinal nerve fiber layer (RNFL) thickness with GDx with variable corneal compensation and the correlation to VFD. The cup area, cup-to-disc area ratio, and mean cup depth were significantly smaller, and the cup shape measure more negative, in the n-AION eyes than in the OAG eyes (P<0.001), whereas rim area was significantly greater (P<0.001). Multivariate analyses showed that none of disc area, rim area, and mean cup depth in the n-AION eyes and only rim area (P = 0.029) in the OAG eyes was significantly associated with mean deviation (MD). Ellipse average of RNFL thickness significantly correlated with MD in the n-AION eyes (P = 0.045) and in the OAG eyes (P = 0.022). Disc topography of eyes with n-AION was quantitatively characterized by small and shallow cupping and a relatively large rim area compared to eyes with OAG matched for age and VFD. In eyes with n-AION, significant correlation with VFD was found only for the RNFL thickness evaluated with SLP but not for the HRT II parameters.
Optic disk size in ischemic optic neuropathy
American Journal of Ophthalmology, 1988
We measured the horizontal diameter, vertical diameter, and area of the optic disk in fellow eyes of patients with unilateral nonarteritic ischemie optic neuropathy and in control eyes without ocular disease. The fellow eyes of patients with anterior ischemie optic neuropathy had a smaller horizontal than vertical disk diameter (P < .05), a difference not present in controls. Both the horizontal disk diameter and the disk area were significantly smaller in fellow eyes of patients with anterior ischemie optic neuropathy than in controls (P < .05). There was no statistical difference in the vertical disk diameters between the two groups. Our findings suggest that a small disk area along with a horizontal shortening of the scierai canal can lead to crowding of optic nerve fibers, predisposing to a circulatory compromise of the optic nerve head in nonarteritic anterior ischemie optic neuropathy.
Key Papers on Optic Disc Evaluation in Glaucoma
Optic nerve diseases, such as the glaucomas, lead to changes in the intrapapillary and parapapillary region of the optic nerve head. These changes can be described by the following variables: size and shape of the optic disk; size, shape, and pallor of the neuroretinal rim; size of the optic cup in relation to the area of the disk; configuration and depth of the optic cup; ratios of cup-to-disk diameter and cup-to-disk area; position of the exit of the central retinal vessel trunk on the lamina cribrosa surface; presence and location of splinter-shaped hemorrhages; occurrence, size, configuration, and location of parapapillary chorioretinal atrophy; diffuse and/or focal decrease of the diameter of the retinal arterioles; and visibility of the retinal nerve fiber layer (RNFL). These variables can be assessed semiquantitively by ophthalmoscopy without applying sophisticated techniques. For the early detection of glaucomatous optic nerve damage in ocular hypertensive eyes before the development of visual field loss, the most important variables are neuroretinal rim shape, optic cup size in relation to optic disk size, diffusely or segmentally decreased visibility of the RNFL, occurrence of localized RNFL defects, and presence of disk hemorrhages. ( Surv Ophthalmol 43 :293-320, 1999. © 1999 by Elsevier Science Inc. All rights reserved.) Key words. cup/disk ratio • neuroretinal rim • optic cup • optic disk • optic disk hemorrhages • optic disk pallor • parapapillary atrophy • peripapillary scleral ring • retinal nerve fiber layer • retinal vessel diameter ABSTRACT Purpose: The major objective of this study was to test the reproducibility of a new method of estimating the amount of optic disc damage in patients with glaucoma.
Investigative Ophthalmology & Visual Science, 2007
PURPOSE. To describe the characteristics of the optic nerve head (ONH) in patients with nonarteritic anterior ischemic optic neuropathy (NAION) and compare them with control subjects by using optical coherence tomography (OCT). METHODS. Patients with NAION underwent a complete ophthalmic examination, including OCT scanning of the ONH at diagnosis. The examination was repeated 1.5, 3, and 6 months later. Age-and sex-matched control subjects with no ocular disease underwent a similar evaluation. Data were obtained by using the ONH analysis protocol of the StratusOCT (Carl Zeiss Meditec, Dublin, CA). RESULTS. Twenty-three patients and 23 control subjects were included. In eyes with NAION, the vertical integrated rim area decreased significantly (P Ͻ 0.01) from the acute phase to the 6-month visit. The cup-to-disc (C/D) area ratio increased significantly (P ϭ 0.002) from the acute examination to the 3-month visit. There was a significant difference between the NAION fellow eyes and the control eyes in C/D ratio, evaluated by slit lamp funduscopy (P Ͻ 0.001), and in the C/D area ratio (P ϭ 0.001). The vertical integrated rim area was significantly (P ϭ 0.001) greater in NAION fellow eyes than in control eyes. There was no significant difference in optic disc area or vertical disc diameter among the control eyes, NAION-affected eyes, and NAION fellow eyes. CONCLUSIONS. Although patients with NAION have lower C/D ratios than does the normal population, with a higher level of nerve fiber crowding, there was no difference in optic disc size between patients with NAION and control subjects. After the development of NAION, 47.8% of eyes had a C/D ratio that differed from that in the fellow eye by more than 0.1. (Invest
PLoS ONE, 2014
To compare the optic nerve head (ONH) structure between compressive optic neuropathy (CON) and glaucomatous optic neuropathy (GON), and to determine whether selected ONH quantitative parameters effectively discriminate between GON and CON, especially CON cases presenting with a glaucoma-like disc. We prospectively assessed 34 patients with CON, 34 age-matched patients with moderate or severe GON, and 34 age-matched healthy control subjects. The quantitative parameters of ONH structure were compared using the Heidelberg Retina Tomograph 2 (HRT2) and Spectralis optical coherence tomography with an enhanced depth imaging method. The mean and maximum cup depths of CON were significantly smaller than those with GON (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001 and P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001, respectively). The distance between Bruch&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s membrane opening and anterior surface of the lamina cribrosa (BMO-anterior LC) of CON was also significantly smaller than that of glaucoma but was similar to that of the healthy group (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001 and P = 0.47, respectively). Based on Moorfields regression analysis of the glaucoma classification of HRT2, 15 eyes with CON were classified with a glaucoma-like disc. The cup/disc area ratio did not differ between cases of CON with a glaucoma-like disc and cases of GON (P = 0.16), but the BMO-anterior LC and mean and maximum cup depths of CON cases with a glaucoma-like disc were smaller than those in GON (P = 0.005, P = 0.003, and P = 0.001, respectively). Measurements of the cup depths and the LC depth had good ability to differentiate between CON with a glaucoma-like disc and glaucoma. There was no laminar remodeling detected by laminar surface position in the patients with CON compared to those with GON.