Active clinical trials for "Glaucoma, Angle-Closure"

To evaluate the influence of superior versus temporal laser peripheral iridotomy location on post-operative visual acuity and contrast sensitivity.

Rationale: Primary angle closure glaucoma (PACG) causes high rates of blindness, either by means of a painful attack of acute angle closure glaucoma or unnoticed over a period of many years. Patients with angle closure are particularly at risk but can be detected during an ophthalmological examination and sent for early preventive (laser) intervention. Current practice shows that patients at risk of PACG are frequently missed during routine examinations. Moreover, new imaging techniques like swept source optical coherence tomography (SS-OCT), are emerging with which the angle of the anterior chamber can be imaged in great detail with no burden for the patient. These techniques are already used in clinical practice and replace and complete part of the ophthalmic examination. However, in Caucasians, it is not yet known to what extent angle closure is detected in regular care and can be detected with this OCT device. There are few published data concerning angle closure and PACG in Caucasians and its characteristics. Objective: To quantify the presence of angle closure by gonioscopy in patients at risk of angle closure on SS-OCT. Secondary objectives are to quantify the presence of an increased intra-ocular pressure during the day or after dark provocation, to quantify morphometric details of the anterior chamber, structural changes, and corneal endothelial cells and to quantify the functional changes of the visual field. Study design: prospective, observational, descriptive study. Study population: Caucasian patients, presenting at the outpatient clinic of the University Eye Clinic Maastricht, aged 40 to 80 years, who are diagnosed with angle closure on SS-OCT. Intervention (if applicable): Not applicable. Main study parameters/endpoints: The main study parameter is assessment of the anterior chamber angle according to gonioscopy. Secondary study parameters are the presence of an increased intra-ocular pressure (IOP) (>21 mmHg) during the day or after dark provocation (IOP rise from baseline), morphometric details of the anterior chamber, structural changes of the retinal nerve fiber layer, number of corneal endothelial cells and functional changes of the visual field Hypothesis: It is hypothesised that, based on its resolution and ease of use, SS-OCT is a suitable imaging technique to identify patients with or at risk of angle closure. It will be of value as an additional diagnostic instrument and may even replace gonioscopy.

since glaucoma is considered an optic neuropathy, new treatments for glaucoma are being continuously investigated, including neuroprotection. Previous studies implied that phenytoin, a potent anti-convulsive drug, has a neuroprotective role, and Na+ channels blockage was suggested as a possible mechanism. This study predicts that glaucoma patients taking Phenytoin will have a less advanced glaucoma as compared to patients not taking the drug. Glaucoma severity will be determined by visual acuity, visual fields, optic disc cupping and nerve fiber layer thickness

The primary purpose of this study is to assess the prevalence of asymptomatic chronic angle closure in high risk Caucasian individuals, namely those with hyperopia. A secondary purpose is to assess whether specific demographic or ocular-anatomic parameters in this population are associated with a higher risk for angle closure.

The Tomey CASIA (Tomey Corporation, Nagoya, Japan) is a novel rapid imaging device that captures high-quality imaging of the entire anterior chamber of the eye over detailed imaging of a single section. In this prospective study, we want to investigate and compare the anatomical structure of the drainage angle of the eye in patients with different types glaucoma using Tomey machine. This study gives us a better understanding of the predictability, validity and accuracy of Tomey machine in the diagnosis of different types of glaucoma. Moreover, the data collected here will be used to create an artificial intelligence (AI) platform to screen certain type of glaucoma.

Primary angle closure diseases (PACD) are commonly seen in Asia. In clinical practice, gonioscopy is the gold standard for angle width classification in PACD patietns. However, gonioscopy is a contact examination and needs a long learning curve. Anterior segment optical coherence tomography (AS-OCT) is a non-contact test which can obtain three dimensional images of the anterior segment within seconds. Therefore, the investigators designed the study to verify if AS-OCT based deep learning algorithm is able to detect the PACD subjects diagnosed by gonioscopy.