الفهرس | Only 14 pages are availabe for public view |
Abstract Glaucoma is the leading cause of irreversible blindness both worldwide and in the Western World. Since glaucomatous damage is preventable but irreversible, an early diagnosis and close follow-up of glaucoma patients are primordial. Optical coherence tomography (OCT) angiography (OCTA) is a recently developed, noninvasive imaging modality that detects blood flow through the motion contrast generated by red blood cells. It can be used to provide a quantitative assessment of the microcirculation of the retina and choroid in various layers. Since glaucoma development and progression are both linked to the loss of retinal vessel density (as either a primary or a secondary effect), this technology has the potential to bring forward new information about the pathophysiology of glaucoma, as well as to help clinicians with glaucoma diagnosis and management. Currently, there are 2 groups of complementary exams used for the diagnosis and follow-up of glaucoma patients: structural (where OCT has a considerable role) and functional (visual field) optic nerve measurements. Both technologies have strengths and limitations. OCT is not dependent on patient response and therefore provides objective information on retinal layers’ thickness, with a high repeatability and reproducibility. However, there is a floor effect for OCT in advanced glaucoma when the OCT parameters reach a base level beyond which little change is seen with increasing severity of glaucoma. So, The Aim of this study is to compare perfusion of the optic disc between normal subjects and subjects with glaucoma (POAG) using OCT-A in order to detect changes in perfusion of the optic disc. To elucidate our aim, this study was prospective study conducted on 20 of healthy subjects and patients with Primary open angle glaucoma to analysis optic nerve head vasculature using optical coherence tomography angiography in Ophthalmology department of Menoufia university hospital, Menoufia, Egypt Summary 77 during the period time from April 2022 to May 2023. All patients were submitted to: History taking for the Age, Sex, residence, Complete ophthalmic examination as: Auto-refraction assessment, Anterior segment examination by slit lamp examination and Intra-Ocular Pressure assessment using applanation tonometer to know whether the disease status is controlled or not. Evaluation of Optical Coherence Tomography Angiography: Optical Coherence Tomography Angiography was performed for all subjects included by a swept source-based OCT angiography instrument to obtain images for quantification of optic disc perfusion and to assess retinal nerve fiber layer thickness. The following parameters were provided: Optic Disc Perfusion: measured as Radial Peripapillary Capillaries Vessel Density (RPC Density) and Retinal Nerve Fiber Layer (RNFL) Thickness. Optic nerve head (ONH) Analysis. The results of this study could be summarized as follow: • There was no significant difference between the normal and glaucoma groups regarding whole image, superior hemi density, inferior hemi density and peripapillary density (p>0.05). • there was a highly statistically significant difference between normal group and glaucoma group regarding C/D V ratio and IOP (p<0.05) while that there was non-statistically significant difference between normal group and glaucoma group regarding RNFLT and inside disc (p>0.05). • There was a highly significant correlation between whole image and sub hemi, INF hemi, peripapillary density, RNFL and IOP (P<0.05). There was non-significant correlation between whole image and age and C/D V Ratio (P > 0.05). • There was a highly significant correlation between SUP HEMI and Whole image, INF hemi, peripapillary density, RNFL and IOP (P < 0.05). There was non-significant correlation between SUP HEMI and age and C/D V Ratio (P > 0.05). Summary 78 • There was a highly significant correlation between superior hemi and whole image, SUP HEMI and peripapillary density, RNFL Cup/Disc V ratio and IOP (P < 0.05). There was a non-significant correlation between sub hemi and age (P > 0.05). • There was a highly significant correlation between eye and peripapillary density (P<0.05). There was a non-significant correlation between eye and Sex, IOP, C/D V ratio, RNFLT, whole image, inside disc, SUP HEMI, and INF HEMI (P > 0.05). • There was a highly significant correlation between C/D V ratio and RNFLT (P<0.05). There was a non-significant correlation between C/D V Ratio and inside disc (P > 0.05). • There was a highly significant correlation between inside disc and INF HEMI (P<0.05). There was a non-significant correlation between inside disc and whole image, peripapillary density and SUP HEMI (P>0.05). |