Acute Angle-Closure Glaucoma (AACG)
No Results
No Results
processing….
Angle closure is defined as the apposition of iris to the trabecular meshwork, which results in increased intraocular pressure (IOP). In acute angle closure (AAC), the process occurs suddenly with a dramatic onset of symptoms, including blurred vision, red eye, pain, headache, and nausea and vomiting. The sudden and severe IOP elevation can quickly damage the optic nerve, resulting in acute angle-closure glaucoma (AACG).
AAC is a true ophthalmic emergency, and a delay in treatment can result in blindness. While immediate treatment can sometimes minimize the amount of visual loss, the best treatment is to stop its occurrence in susceptible individuals. [1, 2, 3, 4]
AAC occurs through a process termed pupillary block. Normally, aqueous humor is produced in the ciliary body, flows through the pupil into the anterior chamber, and drains into the trabecular meshwork to exit the eye. When the pupil is mid-dilated, the distance between the iris and the lens is the shortest, and the two structures can come into contact with each other in individuals at risk for angle closure. When this occurs, aqueous humor cannot flow through the pupil into the anterior chamber (pupillary block), pushing the iris forward. When the iris is pushed against the trabecular meshwork, aqueous humor cannot flow out of the eye (angle closure), increasing IOP.
The normal IOP is 10-21 mm Hg. In AAC, and IOP typically exceeds 40 mm Hg. The sudden and severe elevation in IOP can cause irreversible optic nerve damage very quickly (acute angle-closure glaucoma).
Mechanisms other than pupillary block can also contribute to primary angle closure, including plateau iris, use of certain medications, increased iris thickness, increased iris volume with dilation, hyperopia, and increased lens thickness in phacomorphic angle closure.
AAC is more common in older individuals. Among persons older than 40 years, AAC is more common in Inuit and Asian persons, less common in whites, and least common in blacks. While AACG usually accounts for a small proportion of glaucoma cases in the general population, it accounts for significant number of glaucoma cases among persons of Eastern Asian and Southeast Asian descent. It is more common among women and individuals with hyperopia. Individuals with family history of AAC or who have had AAC in one eye are also at a higher risk. [2, 5]
The prognosis is favorable with early detection and treatment. The best way to prevent loss of vision is to treat susceptible individuals prior to AAC.
AAC is a medical emergency that needs to be treated immediately. Even with immediate treatment, AAC may result in vision loss. The best method for preventing vision loss due to AAC is prophylactic treatment in patients with susceptible anatomy.
Patients need to promptly seek an eye care professional if symptoms (pain, decreased vision, headache, and vomiting) suggest AAC.
Allingham RR et al. Shields Textbook of Glaucoma. 6th ed. Philadelphia, PA: Lippencott Williams & Wilkins; 2011.
Cioffi GA et al. Basic and Clinical Science Course. Book 10: Glaucoma. San Francisco, CA: American Academy of Ophthalmology; 2014.
Kahook MY, Schuman JS. Chandler and Grant’s Glaucoma. 5th ed. 2013.
Bope ET, Kellerman R. Conn’s Current Therapy. 2016.
Quigley HA, Broman AT. The number of people worldwide with glaucoma worldwide 2010 and 2020. Br J Ophthalmol. 2006. 90:262-7. [Medline].
Ritch R. Plateau iris Is caused by abnormally positioned ciliary processes. J Glaucoma. 1992. 1:23-6.
Li Y, Wang YE, Huang G, Wang D, He M, Qiu M, et al. Prevalence and characteristics of plateau iris configuration among American Caucasian, American Chinese and mainland Chinese subjects. Br J Ophthalmol. 2014. 98(4):474-8. [Medline].
Ah-Kee EY, Egong E, Shafi A, Lim LT, Yim JL. A review of drug-induced acute angle closure glaucoma for non-ophthalmologists. Qatar Med J. 2015. 1:6. [Medline].
Czyz CN, Clark CM, Justice JD, Pokabla MJ, Weber PA. Delayed Topiramate-induced Bilateral Angle-Closure Glaucoma. J Glaucoma. 2013. 23(8):577-8. [Medline].
Wang BS, Narayanaswamy A, Amerasinghe N, Zheng C, He M, Chan YH, et al. Increased iris thickness and assoication with primary angle closure glaucoma. Br J Ophthalmol. 2011. 95(1):46-50. [Medline].
Lee RY, Huang G, Porco TC, Chen YC, He M, Lin SC. Differences in iris thickness among African Americans, Caucasian Americans, Hispanic Americans, Chinese Americans, and Filipino-Americans. J Glaucoma. 2013. 22(9):673-8. [Medline].
Aptel F, Denis P. Optical coherence tomography quantitative analysis of iris volume changes after pharmacologic mydriasis. Ophthalmology. 2010. 117(1):3-10. [Medline].
Quigley HA, Silver DM, Friedman DS, He M, Plyler RJ, Eberhart CG, et al. Iris cross-sectional area decreases with pupil dilation and its dynamic behavior is a risk factor in angle closure. J Glaucoma. 2009. 18(3):173-9. [Medline].
Nolan W. Anterior segment imaging: ultrasound biomicroscopy and anterior segment optical coherence tomography. Curr Opin Ophthalmol. 2008. 19(2):115-21. [Medline].
Liu J1, Lamba T, Belyea DA. Peripheral laser iridoplasty opens angle in plateau iris by thinning the cross-sectional tissues. Br J Ophthalmol. 2011. 95(1):46-50. [Medline].
Ritch R, Tham CC, Lam DS. Argon laser peripheral iridoplasty (ALPI): an update. Surv Ophthalmol. 2007. 52(3):279-88. [Medline].
Lai JS, Tham CC, Chan JC. The clinical outcomes of cataract extraction by phacoemulsification in eyes with primary angle-closure glaucoma (PACG) and co-existing cataract: a prospective case series. J Glaucoma. 2006. 15(1):47-52. [Medline].
Albert P Lin, MD Assistant Professor, Department of Ophthalmology, Baylor College of Medicine; Staff Physician, Michael E DeBakey Veterans Affairs Medical Center; Ophthalmologist, Ophthalmology Consultants of Houston
Albert P Lin, MD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, Harris County Medical Society, Texas Medical Association
Disclosure: Nothing to disclose.
Kristin Schmid Biggerstaff, MD Assistant Professor, Department of Ophthalmology, Baylor College of Medicine; Staff Physician, Michael E DeBakey Veterans Affairs Medical Center
Kristin Schmid Biggerstaff, MD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, American Society of Cataract and Refractive Surgery
Disclosure: Nothing to disclose.
Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Martin B Wax, MD Professor, Department of Ophthalmology, University of Texas Southwestern Medical School; Vice President, Research and Development, Head, Ophthalmology Discovery Research and Preclinical Sciences, Alcon Laboratories, Inc
Martin B Wax, MD is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society, Society for Neuroscience
Disclosure: Nothing to disclose.
Inci Irak Dersu, MD, MPH Associate Professor of Clinical Ophthalmology, State University of New York Downstate College of Medicine; Attending Physician, SUNY Downstate Medical Center, Kings County Hospital, and VA Harbor Health Care System
Inci Irak Dersu, MD, MPH is a member of the following medical societies: American Academy of Ophthalmology, American Glaucoma Society
Disclosure: Nothing to disclose.
Kilbourn Gordon, III, MD, FACEP Urgent Care Physician
Kilbourn Gordon, III, MD, FACEP is a member of the following medical societies: American Academy of Ophthalmology, Wilderness Medical Society
Disclosure: Nothing to disclose.
Robert J Noecker, MD, MBA Associate Professor, Department of Ophthalmology, University of Pittsburgh School of Medicine; Director, Glaucoma Service, Vice Chair, Department of Ophthalmology, University of Pittsburgh Medical Center Eye Center
Robert J Noecker, MD, MBA is a member of the following medical societies: American Academy of Ophthalmology, Association for Research in Vision and Ophthalmology, American Glaucoma Society, American Medical Association, American Society of Cataract and Refractive Surgery
Disclosure: Received consulting fee from Allergan for consulting; Received grant/research funds from Allergan, Zeiss, Lumenis for other; Received honoraria from Allergan, Alcon, Lumenis, Endo-optics for speaking and teaching.
Malik Y Kahook, MD Clinical Instructor of Ophthalmology, Fellow in Glaucoma, Department of Ophthalmology, University of Pittsburgh Medical Center
Malik Y Kahook, MD is a member of the following medical societies: American Academy of Ophthalmology, American Society of Cataract and Refractive Surgery, Association for Research in Vision and Ophthalmology, Colorado Medical Society
Disclosure: Received consulting fee from Alcon for consulting.
Acute Angle-Closure Glaucoma (AACG)
Research & References of Acute Angle-Closure Glaucoma (AACG)|A&C Accounting And Tax Services
Source
0 Comments