What are the main causes of acute angle closure glaucoma. How can you recognize its symptoms. What treatment options are available for this serious eye condition. How can you prevent acute angle closure glaucoma

What is Acute Angle Closure Glaucoma?

Acute angle closure glaucoma is a serious eye condition characterized by a rapid increase in intraocular pressure (IOP). This sudden rise in pressure can occur within hours and is caused by the inability of fluid to drain properly from the eye. Unlike other forms of glaucoma that develop gradually, acute angle closure glaucoma presents as a medical emergency that requires immediate attention.

The condition arises when the angle between the iris (the colored part of the eye) and the cornea (the clear outer layer) narrows or closes completely. This closure obstructs the drainage canals, preventing the normal flow of fluid and resulting in a dangerous buildup of pressure within the eye.

How does acute angle closure glaucoma differ from other types of glaucoma?

Acute angle closure glaucoma is distinct from other forms of glaucoma in several ways:

• Rapid onset: Symptoms develop quickly, often within hours
• Severity: The condition can cause intense pain and visual disturbances
• Emergency nature: Immediate medical intervention is necessary to prevent vision loss
• Rarity: It is less common than open-angle glaucoma, which progresses more slowly

What Causes Acute Angle Closure Glaucoma?

The primary cause of acute angle closure glaucoma is the blockage of the eye’s drainage system. This obstruction can occur due to various factors:

Anatomical predisposition

Some individuals have naturally narrow drainage angles in their eyes, making them more susceptible to angle closure. This anatomical feature is more common in:

• People of Asian or Inuit descent
• Individuals who are farsighted
• People between the ages of 55 and 65

Pupil dilation triggers

Certain situations that cause the pupil to dilate can precipitate an acute attack in susceptible individuals:

• Entering a dark room
• Receiving eye drops that dilate the pupil
• Experiencing excitement or stress
• Taking certain medications, such as antidepressants, cold medications, or antihistamines

Underlying health conditions

Several health conditions can contribute to the development of acute angle closure glaucoma:

• Cataracts
• Ectopic lens (displacement of the eye’s lens)
• Diabetic retinopathy
• Ocular ischemia (reduced blood flow to the eye)
• Uveitis (eye inflammation)
• Tumors

Recognizing the Symptoms of Acute Angle Closure Glaucoma

The symptoms of acute angle closure glaucoma are typically severe and develop rapidly. Recognizing these signs is crucial for seeking prompt medical attention:

What are the primary symptoms of an acute angle closure glaucoma attack?

The main symptoms include:

• Intense eye pain
• Severe headache
• Nausea and vomiting
• Blurred or hazy vision
• Perception of halos or rainbows around lights
• Redness in the white part of the affected eye
• Dilated or uneven pupils
• Sudden loss of vision

It’s important to note that these symptoms are typically impossible to ignore due to their severity and rapid onset. If you experience any combination of these symptoms, seek immediate medical attention from an ophthalmologist.

Diagnosing Acute Angle Closure Glaucoma

Given the urgent nature of acute angle closure glaucoma, prompt and accurate diagnosis is essential. Ophthalmologists employ several diagnostic techniques to assess the condition:

What diagnostic tests are used to confirm acute angle closure glaucoma?

The primary diagnostic tests include:

1. Gonioscopy: This procedure uses a special lens and a slit lamp microscope to examine the angle between the iris and cornea, assessing the drainage system’s functionality.
2. Tonometry: This test measures the intraocular pressure, which is typically elevated in acute angle closure glaucoma.
3. Ophthalmoscopy: Using a small lighted device, the ophthalmologist examines the optic nerve for signs of damage caused by increased pressure.

In addition to these tests, the ophthalmologist will conduct a thorough eye examination and review the patient’s medical history and symptoms. The combination of clinical findings and diagnostic test results allows for an accurate diagnosis and guides treatment decisions.

Treatment Options for Acute Angle Closure Glaucoma

The primary goal of treatment for acute angle closure glaucoma is to rapidly reduce intraocular pressure and prevent permanent damage to the optic nerve. Treatment typically involves a combination of medications and surgical interventions.

What are the immediate treatment steps for acute angle closure glaucoma?

The initial treatment focuses on lowering eye pressure and may include:

• Eye drops to constrict the pupil and improve fluid drainage
• Oral or intravenous medications to reduce fluid production in the eye
• Pain management medications to alleviate discomfort

What surgical interventions are used to treat acute angle closure glaucoma?

Once the initial pressure is somewhat controlled, laser or surgical procedures may be performed:

1. Laser iridotomy: This procedure creates a small hole in the iris to improve fluid drainage. It’s typically performed on an outpatient basis and takes only a few minutes.
2. Laser iridoplasty or gonioplasty: This technique uses laser energy to pull the edges of the iris away from the drainage canals, improving fluid outflow.
3. Cataract surgery: In cases where cataracts contribute to the angle closure, removing the clouded lens can help resolve the issue.

It’s worth noting that even if only one eye is affected, treatment is often performed on both eyes as a preventive measure. In some cases, additional surgery may be necessary if initial treatments do not provide adequate drainage.

Prevention Strategies for Acute Angle Closure Glaucoma

While not all cases of acute angle closure glaucoma can be prevented, there are steps individuals can take to reduce their risk, especially if they have known risk factors.

How can you reduce your risk of experiencing an acute angle closure glaucoma attack?

Prevention strategies include:

• Regular eye exams: Routine check-ups allow ophthalmologists to monitor eye pressure and drainage angles, especially in high-risk individuals.
• Awareness of risk factors: Understanding personal risk factors, such as family history or anatomical predisposition, can help individuals stay vigilant.
• Medication management: Being cautious with medications that can dilate pupils, particularly if you’re at high risk.
• Prophylactic treatment: In some high-risk cases, ophthalmologists may recommend preventive laser treatment to reduce the likelihood of an acute attack.

It’s important to discuss your individual risk factors and prevention strategies with your eye care professional to develop a personalized plan for maintaining eye health and preventing acute angle closure glaucoma.

Living with Acute Angle Closure Glaucoma: Long-term Management and Outlook

Following an acute angle closure glaucoma attack, ongoing management is crucial to prevent future episodes and maintain eye health. Understanding the long-term implications and adopting appropriate lifestyle changes can significantly impact the prognosis.

What does long-term management of acute angle closure glaucoma involve?

Long-term management typically includes:

• Regular follow-up appointments with an ophthalmologist
• Consistent use of prescribed eye drops or medications
• Monitoring for signs of increased intraocular pressure
• Lifestyle modifications to reduce risk factors
• Ongoing assessment of visual field and optic nerve health

Patients who have experienced an acute angle closure glaucoma attack should be prepared for lifelong eye care management. While the condition can be effectively controlled with proper treatment, vigilance is key to preventing future episodes and preserving vision.

What is the long-term outlook for individuals who have experienced acute angle closure glaucoma?

The prognosis for acute angle closure glaucoma largely depends on how quickly treatment is initiated and how effectively the condition is managed. With prompt intervention and appropriate long-term care, many individuals can maintain good vision and eye health. However, some may experience some degree of permanent vision loss, particularly if there was significant delay in seeking treatment during the acute attack.

It’s essential for patients to understand that while acute angle closure glaucoma is a serious condition, advances in treatment and management strategies have greatly improved outcomes. By working closely with their eye care team and adhering to recommended treatments and lifestyle modifications, many individuals can successfully manage the condition and maintain a good quality of life.

Research and Advancements in Acute Angle Closure Glaucoma

The field of ophthalmology continues to evolve, with ongoing research aimed at improving our understanding, diagnosis, and treatment of acute angle closure glaucoma. These advancements offer hope for better outcomes and potentially new preventive strategies.

What are some recent developments in acute angle closure glaucoma research?

Recent areas of focus in acute angle closure glaucoma research include:

• Genetic studies to identify risk factors and potential targets for therapy
• Advanced imaging techniques for earlier detection of narrow angles
• Development of new medications to lower intraocular pressure more effectively
• Refinement of surgical techniques to improve outcomes and reduce complications
• Investigation of neuroprotective agents to preserve optic nerve function

These research efforts aim to enhance our ability to predict, prevent, and treat acute angle closure glaucoma, potentially reducing the incidence of vision loss associated with this condition. As new findings emerge, treatment protocols and preventive strategies may continue to evolve, offering hope for improved outcomes for individuals at risk of or affected by acute angle closure glaucoma.

In conclusion, acute angle closure glaucoma remains a serious eye condition that requires prompt recognition and treatment. By understanding its causes, recognizing its symptoms, and seeking immediate medical attention when necessary, individuals can significantly improve their chances of preserving vision and maintaining eye health. Ongoing research and advancements in the field offer promise for even better management and outcomes in the future.

Acute Angle Closure Glaucoma: Causes, Symptoms, Treatment

Written by Rachel Reiff Ellis

• Causes
• Symptoms
• Diagnosis
• Treatment
• Prevention

This serious condition makes the pressure inside your eye (your doctor may call it intraocular pressure, or IOP) go up suddenly. It can rise within a matter of hours. It happens when fluid in your eye can’t drain the way it should. It isn’t as common as other types of glaucoma, which cause pressure buildup much more slowly over time.Acute angle-closure glaucoma is caused by a rapid or sudden increase in pressure inside the eye, called intraocular pressure (IOP).

Fluid drains out of your eye through a system of canals. These canals live in a mesh of tissue between your iris (the colored part of your eye) and your cornea (the clear outer layer).

When your iris and cornea move closer together, it “closes the angle” between them. When this happens suddenly, it’s called an acute attack and is very painful.

Acute angle closure glaucoma completely blocks your canals. It stops fluid from flowing through them, kind of like a piece of paper sliding over a sink drain. The pressure that builds up can damage your optic nerve. If you don’t treat the problem quickly enough, you could lose your sight completely.

You might have an attack of angle closure glaucoma if you have narrow drainage systems and your eyes dilate (your pupil gets bigger) too much or too quickly. This can normally happen when you:

• Go into a dark room
• Get drops that dilate your eyes
• Are excited or stressed
• Take certain drugs like antidepressants, cold medications, or antihistamines

Some health conditions can also cause angle closure glaucoma:

• Cataracts
• Ectopic lens (when your lens moves from where it should be)
• Diabetic retinopathy
• Ocular ischemia (narrowed blood vessels to the eye)
• Uveitis (eye inflammation)
• Tumors

Women are 2 to 4 times more likely to get it than men. You’re also more likely to have it if you’re:

• Asian or Inuit
• Farsighted
• Between 55 and 65

Or if you:

• Have a family history of it
• Use medications that dilate your pupils
• Use other medications that cause your iris and cornea to come together, like sulfonamides, topiramate, or phenothiazines

If you have acute angle closure glaucoma in one eye, you’re also more likely to get it in the other.

They come on quickly. You won’t be able to ignore them. They include:

• Eye pain
• Severe headache
• Nausea or vomiting
• Very blurry or hazy vision
• Seeing rainbows or halos around lights
• Redness in the white part of the affected eye
• Pupils of different sizes
• Sudden loss of sight

When your doctor examines you, they may also notice that your pupils no longer get smaller or bigger when they shine light on them.

If you think you have acute angle closure glaucoma, you’ll need to see an ophthalmologist right away — it’s an emergency. They’ll examine you and ask about your symptoms. They may do one or more tests to find out more about what’s going on inside your eye:

• Gonioscopy: The doctor uses a lens with a simple microscope called a slit lamp to look into your eye. A beam of light checks the angle between your iris and cornea and see how well fluid drains.
• Tonometry: This test uses a tool to measure the pressure inside your eye.
• Ophthalmoscopy: Your doctor checks for damage to your optic nerve with a small lighted device.

The first thing your doctor will do to treat your acute angle closure attack is try to get rid of some of the pressure in your eye. They might use:

• Drops that narrow your pupil
• Medication to lowers the amount of fluid your eye makes

Once your IOP has dropped a little, your doctor may use a laser to:

• Make a small hole in your iris. This is called a laser iridotomy, and it helps the fluid start flowing again inside your eye. It’s an outpatient treatment, and takes a few minutes.
• Pull the edges of your iris away from your drainage canals. This called laser iridoplasty or gonioplasty.

If you have cataracts, your doctor may consider surgery to replace the lens in your eye. This type of surgery can be harder to do when you’re having an acute attack.

Even if your acute angle closure glaucoma is in only one eye, your doctor will probably treat both eyes, just to be safe. You may need further surgery if this does not allow a passage for enough drainage of fluid.

The best way to prevent an acute angle closure glaucoma attack is to get your eyes checked regularly, especially if you’re at high risk. Your doctor can keep tabs on pressure levels and how well fluid drains. If they think your risk is unusually high, they may suggest laser treatment to hold off an attack.

Top Picks

Acute Angle Closure Glaucoma: Causes, Symptoms, Treatment

Written by Rachel Reiff Ellis

• Causes
• Symptoms
• Diagnosis
• Treatment
• Prevention

This serious condition makes the pressure inside your eye (your doctor may call it intraocular pressure, or IOP) go up suddenly. It can rise within a matter of hours. It happens when fluid in your eye can’t drain the way it should. It isn’t as common as other types of glaucoma, which cause pressure buildup much more slowly over time.Acute angle-closure glaucoma is caused by a rapid or sudden increase in pressure inside the eye, called intraocular pressure (IOP).

Fluid drains out of your eye through a system of canals. These canals live in a mesh of tissue between your iris (the colored part of your eye) and your cornea (the clear outer layer).

When your iris and cornea move closer together, it “closes the angle” between them. When this happens suddenly, it’s called an acute attack and is very painful.

Acute angle closure glaucoma completely blocks your canals. It stops fluid from flowing through them, kind of like a piece of paper sliding over a sink drain. The pressure that builds up can damage your optic nerve. If you don’t treat the problem quickly enough, you could lose your sight completely.

You might have an attack of angle closure glaucoma if you have narrow drainage systems and your eyes dilate (your pupil gets bigger) too much or too quickly. This can normally happen when you:

• Go into a dark room
• Get drops that dilate your eyes
• Are excited or stressed
• Take certain drugs like antidepressants, cold medications, or antihistamines

Some health conditions can also cause angle closure glaucoma:

• Cataracts
• Ectopic lens (when your lens moves from where it should be)
• Diabetic retinopathy
• Ocular ischemia (narrowed blood vessels to the eye)
• Uveitis (eye inflammation)
• Tumors

Women are 2 to 4 times more likely to get it than men. You’re also more likely to have it if you’re:

• Asian or Inuit
• Farsighted
• Between 55 and 65

Or if you:

• Have a family history of it
• Use medications that dilate your pupils
• Use other medications that cause your iris and cornea to come together, like sulfonamides, topiramate, or phenothiazines

If you have acute angle closure glaucoma in one eye, you’re also more likely to get it in the other.

They come on quickly. You won’t be able to ignore them. They include:

• Eye pain
• Severe headache
• Nausea or vomiting
• Very blurry or hazy vision
• Seeing rainbows or halos around lights
• Redness in the white part of the affected eye
• Pupils of different sizes
• Sudden loss of sight

When your doctor examines you, they may also notice that your pupils no longer get smaller or bigger when they shine light on them.

If you think you have acute angle closure glaucoma, you’ll need to see an ophthalmologist right away — it’s an emergency. They’ll examine you and ask about your symptoms. They may do one or more tests to find out more about what’s going on inside your eye:

• Gonioscopy: The doctor uses a lens with a simple microscope called a slit lamp to look into your eye. A beam of light checks the angle between your iris and cornea and see how well fluid drains.
• Tonometry: This test uses a tool to measure the pressure inside your eye.
• Ophthalmoscopy: Your doctor checks for damage to your optic nerve with a small lighted device.

The first thing your doctor will do to treat your acute angle closure attack is try to get rid of some of the pressure in your eye. They might use:

• Drops that narrow your pupil
• Medication to lowers the amount of fluid your eye makes

Once your IOP has dropped a little, your doctor may use a laser to:

• Make a small hole in your iris. This is called a laser iridotomy, and it helps the fluid start flowing again inside your eye. It’s an outpatient treatment, and takes a few minutes.
• Pull the edges of your iris away from your drainage canals. This called laser iridoplasty or gonioplasty.

If you have cataracts, your doctor may consider surgery to replace the lens in your eye. This type of surgery can be harder to do when you’re having an acute attack.

Even if your acute angle closure glaucoma is in only one eye, your doctor will probably treat both eyes, just to be safe.  You may need further surgery if this does not allow a passage for enough drainage of fluid.

The best way to prevent an acute angle closure glaucoma attack is to get your eyes checked regularly, especially if you’re at high risk. Your doctor can keep tabs on pressure levels and how well fluid drains. If they think your risk is unusually high, they may suggest laser treatment to hold off an attack.

Top Picks

When to use laser iridoplasty? | World of Ophthalmology

Author:
Leibman Jeffrey M. – MD
Other publications by this author

06/09/2016 23:39

Angle-closure glaucoma is a group of various diseases characterized by specific iridotrabecular interposition, trabecular damage and dysfunction, increased IOP, glaucomatous optic neuropathy and loss of field of vision.

Although angle closure can develop for a variety of reasons, laser iridectomy successfully eliminates relative pupillary block from the angle closure process, whether pupillary block is the leading mechanism for angle closure or angle closure is due to some other mechanisms.

Argon laser peripheral iridoplasty (ALPI) is a laser surgical technique designed to reduce or eliminate iridotrabecular contact when laser iridotomy is unable to open an oppositionally closed angle (a mechanism not related to pupillary block) or when laser iridotomy is not possible. Great attention to the differential diagnosis of angle closure remains a key factor in the early identification of eyes that will not respond favorably to laser iridotomy or that may develop re-angle closure.

It should be noted that angle closure associated with the occurrence and development of peripheral and anterior synechiae (synechial angle closure) cannot be reversed by iridoplasty.

Sustained angle closure following successful laser iridotomy and resolution of pupillary block usually follows when the angle closure process has an underlying cause beyond the plane of the iris. This can happen at the level of the ciliary body, the lens, or forces originating from the posterior segment. Flat iris configuration (syndrome), lens-induced angle closure (swelling, subluxed or dislocated lens), processes occurring in the posterior segment of the eye (syndromes of malignant glaucoma, occlusion of the central retinal vein, scleroplastic surgery for retinal detachment, extensive panretinal laser coagulation, posterior scleritis, medically induced vascular detachment) are potential causes of angle closure mechanism not related to pupillary block.

ALPI is usually indicated to reduce or eliminate residual or persistent irido-trabecular contact in eyes with a functioning iridotomy. An iridotomy can only be recognized as functional if the anterior lens capsule can be visualized through iridotomy or reduced prominence of the peripheral iris can be demonstrated on instrumental anterior segment imaging (OST, UBM, Orbiscan, Shemphlug). Any residual pupillary block will negate the effect of even a successful iridoplasty over time.

Special indications for argon laser peripheral iridoplasty.

1. residual oppositional angle closure after laser iridotomy:

Pupillary block is the cause of irido-trabecular contact in the vast majority of eyes with angle-closure glaucoma and is corrected with laser iridotomy. ALPI is indicated if gonioscopy confirms persistent irido-trabecular contact. ALPI is not indicated if gonioscopy reveals only synechial angle closure without residual opposition. The flat iris configuration is the most common cause of recurrent iridotrabecular contact and responds well to iridoplasty. Eyes with a shallow anterior segment due to lens enlargement or anterior lens subluxation (eg, Zinn ligament laxity in pseudoexfoliative syndrome) also respond well to ALPI.

2. Acute anterior chamber angle closure with functioning laser iridotomy:

Recurrent angle closure after successful iridotomy is associated with a blocking mechanism without pupillary block. ALPI can be done to interrupt an acute attack (described below) or to widen the angle after an acute attack has been blocked.

3. acute attack of angle-closure glaucoma when iridotomy is not possible due to turbid media:

Treatment of acute angle closure is to reduce IOP and restore the anatomical relationship. In cases where medical therapy fails to reduce IOP or laser iridotomy cannot be performed due to media turbidity, ALPI can be used to interrupt an acute attack, lower IOP, and create a window of time so that medical therapy can take effect and enable laser therapy. iridotomy through transparent media. For many eyes with angle closure related to the location of the lens, ALPI can create a window of time to reduce the inflammatory response and lower IOP before cataract extraction. Even if the attack is blocked, iridotomy or cataract surgery (if necessary) should be performed as early as possible to eliminate any relative pupillary block that remains.

4. recurrent angle closure after iridotomy and iridoplasty:

Eyes requiring ALPI often have unusual angle configuration or eye anatomy. Intermittent gonioscopy should be routinely performed to detect progressive angle narrowing with recurrent irido-trabecular contact and may indicate an indication for revision iridoplasty even years after initially successful treatment.

5. before laser trabeculoplasty when the angle remains anatomically narrow after iridotomy:

In some patients, the anatomically narrow angle makes laser trabeculoplasty technically challenging. ALPI can be used to widen the angle in some patients in whom repositioning the lens and changing the direction of gaze during trabeculoplasty does not provide an adequate gonioscopic image. These eyes have an angle that is too narrow for direct trabeculoplasty and are at increased risk of developing peripheral anterior synechia after the procedure. Other glaucoma therapies, often in combination with lens removal, may be a better alternative for these eyes.

Surgical technique ALPI.

Successful laser iridoplasty depends on correct localization of laser applications to the periphery of the iris. Each focus should be large (spot size 500 μm), the pulse should be long (0.5-0.7 sec.), Relatively low energy (200-500 mW, depending on the pigmentation of the iris). The Abraham type lens improves targeting of the laser beam, which must pass partially through the limbal zone in order to ensure that the focus is adequately peripheral. The immediate effect of laser exposure is to shrink the iris towards the center of the laser spot. A total of 24-30 applications should be located around the circumference, visible vessels should be excluded from the application area.

Postoperative treatment with steroid instillations 4 times a day for 4 days is usually sufficient to minimize the intraocular inflammatory response. Healed laser applications are usually seen at the extreme periphery of the iris.

Fig. 1. Peripheral circular laser iridoplasty applications on the eye with a flat iris and laser iridotomy.

Conclusion:

Iridoplasty is a useful technique for widening the anterior chamber angle when properly applied clinically. Although the technique is quite simple and detailed in many sources, care must be taken to avoid complications such as iris ischemia, chronic inflammation, peripheral anterior synechia, and corneal trauma.

Careful placement of laser applications and proper selection of patients yields positive results in these severe cases of angle-closure glaucoma.

Literature :

1. Ritch R, Liebmann JM. Argon laser peripheral iridoplasty. Ophthalmic Surg Lasers . 1996;27:289-300.

2. Liebmann JM, Ritch R. Laser surgery for angle closure glaucoma. Semin Ophthalmol. 2002;17:84-91.

3. Ritch R, Tham CC, Lam DS. Argon laser peripheral iridoplasty (ALPI): an update. Surv Ophthalmol. 2007; 52:279-288.

4. Ritch R. Argon laser treatment for medically unresponsive attacks of angle-closure glaucoma. Am J Ophthalmol. 1982;94:197-204.

Rationale for early lens removal in the treatment of primary anterior chamber angle closure disease | Kurysheva

1. Foster P.J., Buhrmann R., Quigley H.A., Johnson G.J. The definition and classification of glaucoma in prevalence surveys. Br J Ophthalmol 2002; 86(2):238-242. https://doi.org/10.1136/bjo.86.2.238

2. Kurysheva N.I., Sharova G.A. The role of optical coherence tomography in the diagnosis of diseases of the closed angle of the anterior chamber. Part 1: Visualization of the anterior segment of the eye. Ophthalmology 2021; 18(2):208-215. https://doi.org/10.18008/1816-5095-2021-2-208-215

3. Quigley H.A. Long-term follow-up of laser iridotomy. Ophthalmology 1981; 88(3):218-224. https://doi.org/10.1016/s0161-6420(81)35038-6

4. Sihota R, Rishi K, Srinivasan G, Gupta V, Dada T, Singh K. Functional evaluation of an iridotomy in primary angle closure eyes. Graefe’s Arch Clin Exp Ophthalmol = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie. 2016; 254(6):1141–9. https://doi.org/10.1007/s00417-016-3298-x

5. Kurysheva N.I., Lepeshkina L.V., Shatalova E.O. Predictors of outcome in selective laser trabeculoplasty: a long-term observation study in primary angle-closure glaucoma after laser peripheral iridotomy compared with primary open-angle glaucoma. J Glaucoma 2018; 27(10):880-886. https://doi.org/10.1097/IJG.0000000000001048

6. Kurysheva N.I., Sharova G.A. Comparative study of retinal microcirculation in primary closed angle disease and initial primary open-angle glaucoma. Bulletin of Ophthalmology 2022; 138(1):44-51. https://doi.org/10.17116/oftalma202213801144

7. Azuara-Blanco A., Burr J., Ramsay C., et al. Effectiveness of early lens extraction for the treatment of primary angle-closure glaucoma (EAGLE): a randomized controlled trial. Lancet 2016; 388(10052): 1389-1397. https://doi.org/10.1016/S0140-6736(16)30956-4

8. Nongpiur M.E., Sakata L.M., Friedman D.S., et al. Novel association of smaller anterior chamber width with angle closure in Singaporeans. Ophthalmology 2010; 117(10):1967-1973. https://doi.org/10.1016/j.ophtha.2010.02.007

9. Marchenko A.N., Sorokin E.L., Pashentsev Ya.E. The effectiveness of the system for predicting the risk of developing an acute attack of angle-closure glaucoma. Bulletin of ophthalmology 2019; 135(1):47-52. https://doi.org/10.17116/oftalma201913501147

10. Ghelichkhani P, Esmaeili M. Prone position in management of COVID-19 patients; a Commentary. Arch Acad Emerge Med 2020; 8(1):e48.

11. Kurysheva N.I. COVID-19 and eye damage: Monograph. M: Largo 2021; 80.

12. Sanghi P., Malik M., Hossain I.T., Manzouri B. Ocular Complications in the Prone Position in the Critical Care Setting: The COVID-19Pandemic. J Intensive Care Med 2021; 36(3):361-372. https://doi.org/10.1177/0885066620959031

13. Sano R., Kurokawa T., Kurimoto Y., Miyazawa D., Yoshimura N. Comparison between the anterior chamber configuration in the supine position and that in the prone position in patients with narrow angle. Nippon Ganka Gakkai Zasshi 2001; 105(6):388-393.

14. Kim T.W., Park K.H., Hong C. Dark-room prone-position test for intermittent angle closure. Korean J Ophthalmol 2007; 21(3):151-154. https://doi.org/10.3341/kjo.2007.21.3.151

15. Yamada R., Hirose F., Matsuki T., Kameda T., Kurimoto Y. Comparison of mydriatic provocative and dark room prone provocative tests for anterior chamber angle configuration. J Glaucoma 2016; 25(6):482-486. https://doi. org/10.1097/IJG.0000000000000310

16. Anderson A.P., Babu G., Swan J.G., et al. Ocular changes over 60 min in supine and prone postures. J Appl Physiol (1985). 2017; 123(2): 415-423. https://doi.org/10.1152/japplphysiol.00687.2016

17. Harris L.S., Galin M.A. Prone provocative testing for narrow angle glaucoma. Arch Ophthalmol 1972; 87(5):493-496. 18. Ostroumova O.D., Shikh E.V., Rebrova E.V., Ryazanova A.Yu., Moshetova L.K. Drug-induced glaucoma. Bulletin of Ophthalmology 2020; 136(2):107-116. https://doi.org/10.17116/oftalma2020136021107

19. Sokolovskaya T.V., Yashina V.N., Makhno N.A. Angle-closure glaucoma, iridocrystalline block, ciliochoroidal detachment and transient myopia while taking topiramate. Ophthalmosurgery 2021;1:57-62. https://doi.org/10.25276/0235-4160-2021-1-57-62

20. Kurysheva N.I., Sharova G.A. The role of optical coherence tomography in the diagnosis of diseases of the closed angle of the anterior chamber. Part 2: Visualization of the posterior segment of the eye. Ophthalmology 2021; 18(3):381-388. https://doi.org/10.18008/1816-5095-2021-3-381-388

21. Nerlikar R.R., Palsule A.C., Vadke S. Bilateral Acute Angle Closure Glaucoma After Prone Position Ventilation for COVID-19 Pneumonia. J Glaucoma 2021; 30(8):e364-e366. https://doi.org/10.1097/IJG.0000000000001864

22. Barosco G., Morbio R., Chemello F., Tosi R., Marchini G. Bilateral angleclosure during hospitalization for coronavirus disease-19 (COVID-19): A case report. Eur J Ophthalmol 2021; 11206721211012197. https://doi.org/10.1177/11206721211012197

23. Tanaka H.G. The Asymptomatic PAC Suspect: LPI or No LPI? Review ophthalmology 2018. Available at: https://www.reviewofophthalmology.com/article/the-asymptomatic-pac-suspect-lpi-or-no-lpi (date of access: 03/11/2022)

24. He M. , Jiang Y., Huang S., Chang D.S., Munoz B., Aung T., Foster P.J., Friedman D.S. Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomized controlled trial. Lancet 2019; 20;393(10181):1609-1618. https://doi.org/10.1016/S0140-6736(18)32607-2

25. Kurysheva N.I., Lepeshkina L.V., Shatalova E.O. Long-term efficacy of selective laser trabeculoplasty in patients with primary angle-closure glaucoma after peripheral laser iridotomy. Ophthalmosurgery 2018; (3):33-40. https://doi.org/10.25276/0235-4160-2018-3-33-40

26. Raj S., Tigari B., Faisal T.T., et al. Correction: Efficacy of selective laser trabeculoplasty in primary angle closure disease. Eye (Lond) 2021; 35(3):1028. https://doi.org/10.1038/s41433-020-1047-1

27. Kurysheva N.I., Maslova E.V., Zolnikova I.V., Fomin A.V., Lagutin M.B. A comparative study of structural, functional and circulatory parameters in glaucoma diagnostics. PLoS One 2018; 13(8):e0201599. https://doi.org/10.1371/journal.pone.0201599

28. Kurysheva N.I., Lepeshkina L.V. Detection of primary angle closure glaucoma progression by optical coherence tomography. J Glaucoma 2021; 30(5):410-420. https://doi. org/10.1097/IJG.0000000000001829

29. Jiang Y., Chang D.S., Zhu H., et al. Longitudinal changes of angle configuration in primary angle-closure suspects: the Zhongshan AngleClosure Prevention Trial. Ophthalmology 2014; 121(9):1699-1705. https://doi.org/10.1016/j.ophtha.2014.03.039

30. Lee K.S., Sung K.R., Kang S.Y., Cho J.W., Kim D.Y., Kook M.S. Residual anterior chamber angle closure in narrow-angle eyes following laser peripheral iridotomy: anterior segment optical coherence tomography quantitative study. Jpn J Ophthalmol 2011; 55(3):213-219. https://doi.org/10.1007/s10384-011-0009-3

31. Shao T., Hong J., Xu J., Le Q., Wang J., Qian S. Anterior chamber angle assessment by anterior -segment optical coherence tomography after phacoemulsification with or without goniosynechialysis in patients with primary angle closure glaucoma. J Glaucoma 2015; 24(9):647-655. 32. Ghadamzadeh M., Karimi F., Ghasemi Moghaddam S., Daneshvar R. Anterior chamber angle changes in primary angle-closure glaucoma following phacoemulsification versus phacotrabeculectomy: A prospective randomized clinical trial. J Glaucoma 2022; 31(3):147-155. https://doi.org/10.1097/IJG.0000000000001977

33. Song M.K., Sung K.R., Shin J.W., Jo Y.H., Won H.J. Glaucomatous progression after lens extraction in primary angle closure disease spectrum. J Glaucoma 2020; 29(8):711-717. https://doi.org/10.1097/IJG.0000000000001537

34. Kurysheva N.I., Sharova G.A. The effectiveness of laser iridotomy in suspected primary angle closure and in primary angle-closure glaucoma. The EYE EYE. 2022; 24(1):20–33. https://doi.org/10.33791/2222-4408-2022-1-20-33

35. Sihota R., Goyal A., Kaur J., Gupta V., Nag T.C. Scanning electron microscopy of the trabecular meshwork: understanding the pathogenesis of primary angle closure glaucoma. Indian J Ophthalmol 2012; 60(3):183-188. https://doi.org/10.4103/0301-4738.95868

36. Kurysheva N., Lepeshkina L.V., Kapkova S.G. Factors affecting the corneal endothelium after selective laser trabeculoplasty in primary open angle and angle closure glaucoma. BMJ Open Ophthalmology 2021; 27(6):e000638.