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Glaucoma
Published in Charles Theisler, Adjuvant Medical Care, 2023
Glaucoma is a group of eye conditions that damage the optic nerve, leading to loss of vision or blindness. Glaucoma develops often as a result of abnormally high pressure in the anterior chamber of the eye. However, not every person with increased eye pressure will develop optic nerve damage.1 There are two major types of glaucoma: open angle and closed angle. Open angle is the most common form, accounting for 90% of all cases. At first, open-angle glaucoma has no symptoms. It causes no pain and vision stays normal. Nonetheless, over time and without treatment, increased intraocular pressure damages the optic nerve. In closed-angle glaucoma, drainage canals are blocked so pressure in the eye increases. Individuals with glaucoma gradually lose their peripheral (side) vision. If glaucoma remains untreated, objects to the side and out of the corner of the eye can be missed. In more advanced cases, patients often report that their vision is like looking through a tunnel. Over time, central vision may also decrease until no vision remains.1
The nervous system and the eye
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
James A.R. Nicoll, William Stewart, Fiona Roberts
Primary closed-angle glaucoma occurs when the drainage angle is blocked because the iris has come forward. This form of glaucoma is of acute onset, with ocular congestion, corneal oedema, and severe pain. If untreated, blindness occurs due to pressure on the blood vessels in the optic disc. Predisposing factors include race (Eskimos and East Asians), female gender, hypermetropia, and predisposing anatomy (narrow angle or plateau iris).
Cholinergic Agonists
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
Rupali Patil, Aman Upaganlawar
Surgical intervention by iridectomy using a surgical laser is helpful in closed-angle glaucoma. Aqueous humor is allowed to drain freely through severely congested, hypertensive eye via an opening in the iris (Fiscella et al., 2011; Weinreb et al., 2014).
Phase Transition Microemulsion of Brimonidine Tartrate for Glaucoma Therapy: Preparation, Characterization and Pharmacodynamic Study
Published in Current Eye Research, 2021
Nivedita Gautam, Karthikeyan Kesavan
Worldwide, glaucoma is the second foremost cause of blindness.5 It is an age related optic neuropathy defined by a slow progressive degeneration of optic nerves which leads to vision loss and blindness. Elevated intraocular pressure (IOP) is the main risk factor for development of the glaucoma which causes damage to the optic nerves.6 In addition, glaucoma is characterized by apoptosis of the ganglion cell and trabecular meshwork (TM) cells. Indeed, the IOP enhances just because of the malfunctioning of TM cells.7 Broadly this disorder can be classified as “open-angle” and “closed-angle” glaucoma, in which open-angle glaucoma being the most common.8 Available drug therapies for treating glaucoma include conventional dosage forms which are associated with low bioavailability and undesirable systemic side effects.
Correlation of the intronic LOXL1 polymorphism rs11638944 with pseudoexfoliation syndrome and glaucoma in a Greek population
Published in Ophthalmic Genetics, 2021
Maria-Kyriaki Papadopoulou, Irini Chatziralli, Konstantina Tzika, Dimitrios Chiras, George Kitsos, Christos Kroupis
Pseudoexfoliation syndrome was defined by the presence of typical exfoliation material on the anterior lens capsule and/or at the pupillary margin in one or both eyes with a normal optic disc and visual field and IOP≤21 mm Hg in both eyes. Inclusion criteria for POAG patients were untreated IOP≥22 mm Hg on at least two diurnal curves, open-normal angle, glaucomatous optic disc and at least three Humphrey visual field tests with glaucomatous defects. Patients with secondary or closed-angle glaucoma were excluded. The criteria for the diagnosis of POAG were according to the guidelines of the European Glaucoma Society (28). Besides the signs of OAG, PXG was defined by the presence of characteristic slit-lamp findings, including exfoliation deposits on the anterior lens capsule and/or at the pupillary margin in one or both eyes.
Uptake and pharmacokinetics of cefuroxime in rabbits after intravitreal, intracameral, and topical dosing: relevance to human ocular injection of cefuroxime
Published in Xenobiotica, 2020
Ravi Kumar Jairam, Sadanand R. Mallurwar, Bhavesh B. Gabani, Ashok Zakkula, Vinay Kiran, Sreekanth Dittakavi, Suresh P. Sulochana, Zainuddin Mohd, Nuggehally R. Srinivas, Ramesh Mullangi
Glaucoma is a form of optic neuropathy leading to specific visual field loss if not properly treated. All types of glaucoma are categorized as open angle or closed angle based on the status of iridocorneal angle (Razeghinejad et al., 2011). Glaucoma-related surgeries and cataract extraction are the most commonly performed procedures in aged people to avoid vision loss; conditions such as age-related macular degeneration, diabetes mellitus-related ocular disease may also contribute for vision loss (Pelletier et al., 2016). Open angle glaucoma contributes to ∼90% of all reported glaucoma cases. Closed angle glaucoma is characterized by an increased intra-ocular pressure (IOP) in posterior chamber due to blockade at the entrance of drainage canals, as represented in the Supplementary Figure 1. In case of open-angled glaucoma, the increase IOP in the anterior chamber is caused by slow and sustained clogging of the drainage canals and this clogging can occur anywhere beyond the entrance of drainage canal. Bacterial endophthalmitis is the most dreaded post-operative complications after glaucoma related surgical procedures because it can lead to severe or permanent visual loss if untreated. The treatment of bacterial endophthalmitis is cumbersome and presents a challenge to the treating physician (Delyfer et al., 2011; Safneck, 2012).