A new algorithm to automatically detect the boundary of optic disk in color fundus images is proposed. The optic disk is located by principal component analysis (PCA) based model, which is employed to initialize active shape model (ASM) to detect the disk boundary. ASM is modi%ed with two aspects: one is the self-adjusting weight in the transformation from shape space to image space; the other ...

PURPOSE To compare the performance of the retinal nerve fiber layer (RNFL) thickness and optic disk algorithms as determined by optical coherence tomography to detect glaucoma. DESIGN Observational cross-sectional study. METHODS setting: Academic tertiary-care center. study population: One eye from 42 control subjects and 65 patients with open-angle glaucoma with visual acuity of > or =20/4...

The identification of MAs is an important phase in the research and grading of suffering from diabetes retinopathy. We present clustering strategy to identify the microaneurysms from the optic disk and cup in the retinal fundus pictures. Fuzzy C-Means (FCM) Clustering is used for clustering the information in which the information factors are grouped with different account level. The first and ...

Pseudopapilledema is used for pathologies that mimicking the optic disc edema. Among these, pseudo papilledema is commonly produced by optic disc drusen (ODD). A 17-year-old female patient was referred to the ophthalmology department from child neurology department with papilledema diagnosis because of bilateral elevated and blurred optic disc. Following ophthalmologic evaluation with fundus ex...

Current-generation CT scanners enable the visualization in vivo of structures and substructures that were previously unobservable. Certainly the orbit and optic nerve/sheath complex have demonstrated a great number of pathologic and normal anatomic variations. It has been found in patients with elevated intracranial pressure that what was previously thought to be simple papilledema in fact mask...

Structural damage in glaucoma often occurs before detectable loss in visual function.1-3 Accurate assessment of the optic disk and retinal nerve fiber layer (RNFL) morphology, however, is not always an easy task. Optical coherence tomograph (OCT), confocal scanning laser ophthalmoscope (CSLO) and scanning laser polarimeter (SLP) are the 3 commonly used imaging instruments for objective measurem...

BACKGROUND Diagnosis of traumatic optic neuropathy is difficult during primary care as a result of the absence of optic disk changes or coexisting injuries that may be more apparent. Although there are functional signs that suggest its presence, the lack of a comparison parameter may further prevent its detection. A case of bilateral traumatic optic neuropathy is analyzed to emphasize the need ...

A micro-oxygen sensor was used to monitor the optic-disk oxygen tension in vivo in the cat. The perfusion pressure of the eye, defined as the systemic arterial blood pressure minus the intraocular pressure, was decreased. This was accomplished both by lowering the systemic arterial blood pressure by increasing the expiratory resistance and by elevating the intraocular pressure. The result of lo...

Visual receptive fields (RFs) were mapped inside and outside the cortical representation of the optic disk in the striate cortex (area V1) of anesthetized and paralyzed Cebus monkeys. Unexpectedly, most cells were found to be binocularly driven, and the RFs mapped with contralateral-eye stimulation progressed in a topographically appropriate fashion as the optic disk sector was crossed. Activat...