Changes in the Diameter of Retinal Vessels After Remote Ischemic Conditioning
Retinal Artery OcclusionRetinal Vein OcclusionRemote ischemic conditioning (RIC) is a therapeutic strategy for protecting organs or tissue against the detrimental effects of acute ischemia-reperfusion injury. It remains unknown whether this can be used in retinal vascular occlusive diseases. The purpose of the present study is to examine whether the autoregulation of retinal vessel diameters in normal persons change after remote ischemic conditioning.
Philadelphia Telemedicine Glaucoma Detection and Follow-Up Study
GlaucomaGlaucoma Suspect11 moreThe goal is to conduct a 5-year prospective, randomized controlled trial to test an innovative, community-based intervention using posterior and anterior fundus photography of the optic nerve and macula and intraocular eye pressure measurements to improve access and utilization of eye care to detect, treat, and manage high-risk patients with previously undiagnosed glaucoma and other eye diseases. Research shows that subject failure to attend follow-up eye care appointments diminishes any previous benefits of community screenings for glaucoma. Greater adherence to follow-up visits can reduce glaucomatous blindness.
Ocular Discomfort Assessment After Intravitreal Injections
Macular DegenerationDiabetic Retinopathy3 moreIn this study, ocular discomfort following intravitreal injection in naïve patients will be studied, as well as the efficacy of wetting agent (Optive eyewash) to prevent ocular discomfort.
Comparison of Phase-variance Optical Coherence Tomography and Fluorescein Angiography in Retinovascular...
Age-related Macular DegenerationDiabetic Retinopathy3 moreThe purpose of this study is to determine whether phase variance optical coherence tomography (PV-OCT), a software-based optical coherence tomography(OCT) image processing technology, can be used to generate angiographic images of the retinochoroidal vasculature that are comparable to those produced by fluorescein angiography (FA), the current gold standard diagnostic test.
The Effect of Transcorneal Stimulation in Cases of Central Retinal Artery Occlusion Using a New...
Central Retinal Artery OcclusionThe purpose of this study is to describe the effect of transcorneal electrical stimulation (TES) with a non conventional biphasic bipolar waveform in central retinal artery occlusion
Reconstruction of Pathological Changes of the Ophthalmic Artery in Patients With Retinal Artery...
Retinal Artery OcclusionRetinal artery occlusions (RAO) cause deterioration in visual acuity and visual fields. In computational fluid dynamics (CFD) studies [1] 10% of ascending emboli caused RAO, the residual 90% embolized into the cerebral arteries. As only 20% of patients with RAO had a history of stroke, there is a discrepancy between CFD-studies and clinical observations. Mead et al. [2] postulated small emboli being washed into the cerebral arteries without causing clinical symptoms of stroke, whereas similar emboli being washed into the ophthalmic artery would cause RAO. There is a discrepancy between CFD-study results and clinical observations in RAO patients, indicating that there could be a high number of RAO-patients having had cerebral ischemies without symptoms of stroke (as postulated by Mead et al.[2]). Purpose of the present study is to evaluate hemodynamic pathological changes at the ophthalmic artery origin in patients with RAO detected with an already existing CFD-model
Changes of Visual Field Defects After IAT for CRAO
Central Retinal Artery OcclusionVisual Field1 moreCentral retinal artery occlusion (CRAO) is an ophthalmic emergency which leads to devastating visual function defects and poor prognosis. Though traditional conservative treatments are widely used, none of them is proved to be effective. A number of meta-analyses and observational studies indicate intravenous thrombolysis to be beneficial in CRAO. Selective intra-arterial thrombolysis (IAT) introducing rt-PA directly into the ophthalmic circulation by super-selective microcatheterization may reduce the complications such as intracranial and systemic hemorrhage. The residual visual field is significant for patients with CRAO who have poor central visual acuity. Thus, it is clinically significant to study the changes in visual fields in eyes with CRAO.
Computer Aided Diagnosis of Multiple Eye Fundus Diseases From Color Fundus Photograph
Diabetic RetinopathyRetinal Vein Occlusion11 moreBlindness can be caused by many ocular diseases, such as diabetic retinopathy, retinal vein occlusion, age-related macular degeneration, pathologic myopia and glaucoma. Without timely diagnosis and adequate medical intervention, the visual impairment can become a great burden on individuals as well as the society. It is estimated that China has 110 million patients under the attack of diabetes, 180 million patients with hypertension, 120 million patients suffering from high myopia and 200 million people over 60 years old, which suggest a huge population at the risk of blindness. Despite of this crisis in public health, our society has no more than 3,000 ophthalmologists majoring in fundus oculi disease currently. As most of them assembling in metropolitan cities, health system in this field is frail in primary hospitals. Owing to this unreasonable distribution of medical resources, providing medical service to hundreds of millions of potential patients threatened with blindness is almost impossible. To solve this problem, this software (MCS) was developed as a computer-aided diagnosis to help junior ophthalmologists to detect 13 major retina diseases from color fundus photographs. This study has been designed to validate the safety and efficiency of this device.
The Effect of A2A Adrenoceptor Stimulation on the Diameter of Retinal Arterioles During Hypoxia...
Retinal Artery OcclusionThe purpose is to investigate how the adenosine affects the diameter regulation of retinal arterioles during changes in oxygen tension. A deeper understanding of the mechanisms involved in diameter regulation of retinal arterioles during changes in oxygen tension can be used to obtain a more detailed understanding of diseases where changes in the diameter regulation of retinal vessels are involved in the disease pathogenesis and possibly point to new therapeutic options for patients with retinal vascular disease, such as diabetic retinopathy and retinal vein thrombosis. Preliminary, a routine ophthalmological evaluation, measurement of blood pressure, and electrocardiogram will be preformed to insure that only healthy test persons are included in the study. The test persons will be randomly allocated to two groups, one group in which protocol 1 is followed by protocol 2, and the other group with the two protocols performed in the reverse order. Protocol 1: Using the DVA, a video recording will capture the diameter of retinal vessels and the changes occurring during stimulation with flickering light. The recording lasts 4.5 minutes and is preformed before and after intravenous injection of adenosine. Protocol 2: The procedures are similar to those of protocol 1 but are performed during breathing of a gas mixture with a reduced oxygen tension to 12,5 %, which results in a reduced oxygen saturation in the blood to 85-90 %.
Study of Arterial Recanalization of the Central Retinal Artery Occlusions
Central Retinal Artery OcclusionCentral retinal artery occlusions (CRAO) are the equivalent of an ischemic stroke (IS) at the retinal level. They share the same risk factors and common pathology. Their incidence is lower (8.5 / 100,000) and the functional prognosis is unfavorable in 80% of cases with visual acuity (VA) <1/10. The diagnosis of an CRAO is clinically based on the sudden occurrence of a decrease in deep visual acuity with fundamentally signs of reactive ischemia. There is no data on early retinal arterial recanalization after CRAO, nor on the relationship between early recanalization (spontaneous or post-thrombolysis) and visual prognosis.