Last updated: October 19, 2023

Summarytoggle arrow icon

Glaucoma is a group of eye diseases associated with acute or chronic destruction of the optic nerve with or without concomitant increased intraocular pressure (IOP). In the US, glaucoma is the second leading cause of blindness in adults following age-related macular degeneration (AMD). The two main types are open-angle glaucoma and angle-closure glaucoma. Open-angle glaucoma accounts for 90% of all cases of glaucoma, is slowly progressive, and is initially often asymptomatic, but leads to bilateral peripheral vision loss over time. With appropriate treatment that lowers IOP (e.g., topical prostaglandins), progression can be stopped before severe damage occurs. Acute angle-closure glaucoma, on the other hand, is characterized by the sudden onset of a painful, red, and hard eye in combination with frontal headache, blurry vision, and halos appearing around lights. Immediate initiation of medical therapy (e.g., timolol eye drops and IV acetazolamide) is crucial to rapidly decrease IOP and prevent vision loss. Chronic angle-closure glaucoma manifests and is managed similarly to open-angle glaucoma.

Epidemiologytoggle arrow icon


Epidemiological data refers to the US, unless otherwise specified.

Overviewtoggle arrow icon

Important types of glaucoma
Open-angle glaucoma Angle-closure glaucoma
Risk factors
Clinical features
  • Initially often asymptomatic
  • Bilateral, progressive visual field loss (from peripheral to central)
Overview of drugs used to treat glaucoma
Mechanism of IOP decrease Drugs Mechanism of action Adverse effects

↓ Synthesis of aqueous humor

  • Via decrease in cAMP
Aqueous humor outflow
  • Decreases resistance through uveoscleral flow

DIrty PARASites PROSper on ALPine BETonies: DIuretics, PARASympathomimetics, PROStaglandins, ALPha agonists, and BETa blockers are drugs for the treatment of glaucoma.


Pathophysiologytoggle arrow icon


Open-angle glaucomatoggle arrow icon


  • Open-angle glaucoma (also chronic glaucoma): generally bilateral, progressive loss of optic nerve fibers with open chamber angles (often with increased IOP), not caused by another systemic or local condition

Etiology [5]


Clinical features [5]

  • Initially often asymptomatic
  • Over time, nonspecific symptoms such as mild headaches, impaired adaptation to darkness
  • Generally bilateral, progressive visual field loss (from peripheral to central)
  • Arcuate scotoma: arch-shaped scotoma that starts from the blind spot

Diagnostics [5]

Treatment of open-angle glaucoma [5]

  • Indicated in all patients diagnosed with open-angle glaucoma (even if asymptomatic)
  • Options include medical therapy, laser surgery, and open surgery
  • Topical prostaglandins are most effective and usually used initially; other drugs (with a different mechanism) may be added if topical prostaglandins are unsuccessful.
    • No decrease in IOP with one drug: Discontinue and replace with another drug or treatment option.
    • Partial response to one drug: Consider combination therapy with other glaucoma medications or switch to an alternative single-agent therapy.
  • Goal of therapy (target IOP): ≥ 25% decrease in pretreatment IOP

Pharmacotherapy [5][6]

The following regimen is the most commonly followed and is also effective in patients with chronic angle-closure glaucoma refractory to laser peripheral iridotomy (see ''Treatment'' in angle-closure glaucoma for further details).

Interventional therapy [5]

Procedures that lower IOP by facilitating drainage of aqueous humor

Procedures that lower IOP by decreasing aqueous humor production

  • Cyclodestructive surgery
    • Indication: glaucoma refractory to other treatment options
    • Procedure: laser or cryosurgical destruction of the ciliary body

Prevention [5]

  • General screening for glaucoma is not considered cost-effective but is currently recommended in the following patient groups:

Angle-closure glaucomatoggle arrow icon

Definition [6][11][12][13]

Etiology/risk factors

Pathophysiology [11][12][13][17][18]

Clinical features

Acute angle-closure glaucoma is a medical emergency, as it can cause permanent vision loss if left untreated!


Approach [6][11][12][13]

Acute angle-closure glaucoma is vision-threatening and requires emergency ophthalmology evaluation as soon as the clinical diagnosis is suspected.

Do not use mydriatic drugs (e.g., atropine and epinephrine) during ophthalmologic examination in patients with acute angle-closure glaucoma! Moreover, do not cover the eye, since darkness induces mydriasis and worsens the condition! [11]

Tonometry [20][21]

Gonioscopy [12]

Slit-lamp examination [6][11][18]

Direct fundoscopy (with undilated pupils) [6][11][18]

Do not dilate the pupils to evaluate the fundus in suspected glaucoma!

Visual acuity [11][23]

Visual field testing [6][13][24]

  • Indication: all patients with glaucoma
  • Techniques
  • Characteristic findings
    • Glaucomatous visual field defects: a characteristic pattern of visual field defects as a result of glaucomatous optic neuropathy [18][24]
      • Early-stage: arcuate or double arcuate (ring) scotoma
        • Loss of peripheral vision especially of the superior and/or inferior hemifields
        • Sparing of central vision
      • Advanced stage
        • Tunnel vision: further constriction of peripheral vision
        • Total or near-total blindness: loss of peripheral and central vision with or without sparing of the temporal field

Treatment of acute angle-closure glaucoma [6][11][13][15][25]

Acute angle-closure glaucoma is an emergency and should be initially managed with IOP-decreasing medications that have a rapid onset of action. Once IOP has decreased, patients should undergo a definitive procedure as soon as possible to prevent recurrence.

General considerations

Initial pharmacotherapy

  • Indication: initiate in all patients as soon as a diagnosis of acute angle-closure glaucoma is made. [6][11][13][15]
  • Initial pharmacological regimen: There is currently no standardized recommendation for empiric management of acute angle-closure glaucoma. The following regimen may be followed with due consideration of any comorbidities. [6][11][13][15]
  • If IOP is still elevated after 30–60 minutes: The following should be given only under the guidance of an ophthalmologist. [15][25]
    • Repeat eye drops from above up to three times. [15]
    • Consider a systemic hyperosmotic agent if IOP remains high after 60 minutes of initiating therapy. [13][25]
      • In patients with nausea: IV mannitol
      • In patients without significant nausea [25]
        • Nondiabetic patients: oral glycerine [25]
        • Diabetic patients: oral isosorbide [11]
  • If IOP is decreasing: Examine for other signs of resolution of the acute attack. [6][13]

Urgent interventional therapy

  • Anterior chamber paracentesis
  • Urgent laser peripheral iridotomy (see ''Interventional therapy'' for details)
    • Indication: all patients within 24–48 hours of resolution of the acute attack [6]

Topical pilocarpine becomes effective only once IOP decreases to < 40 mm Hg.

Acute management checklist for acute angle-closure glaucoma [6][11][30]

  • Emergency ophthalmology consult
  • Place patient in a supine position.
  • Initiate pharmacotherapy as soon as the diagnosis is made.
  • Consider hyperosmotic pharmacotherapy if initial treatment is unsuccessful.
  • Supportive care, as needed
  • Admit patient or transfer to a hospital with ophthalmology department capable of performing LPI.

Treatment of chronic primary angle-closure glaucoma [6][11][12]

Chronic angle-closure glaucoma with pupillary block should be initially managed with laser surgery (e.g., peripheral iridotomy) or open surgery (iridectomy) to prevent the progression of glaucomatous optic neuropathy and consequent visual field loss. Long-term pharmacotherapy is required if IOP elevation is refractory to the intervention or in patients without pupillary block.

Interventional therapy [6][11][12][13]

Acute angle-closure glaucoma and chronic primary angle-closure with pupillary block

  • Laser peripheral iridotomy (LPI)
  • Laser peripheral iridoplasty (gonioplasty)
  • Surgical peripheral iridectomy [11][14][31]
    • Indication: an alternative to LPI in patients with acute/chronic angle-closure glaucoma with pupillary block [11][31]
    • Procedure: the surgical excision of a small amount of iris tissue to allow for aqueous flow
    • Disadvantages
      • Costly
      • Postoperative recovery period
      • Surgical complications

Chronic primary angle-closure glaucoma without pupillary block [6]

Secondary angle-closure glaucoma [6][31]

Congenital glaucomatoggle arrow icon


  • < 1% of children are born with the condition in the US.
  • Bilateral in ∼ 75% of cases
  • Most cases are diagnosed within the first year of life.



Clinical features



Referencestoggle arrow icon

  1. Prum BE, Herndon LW, Moroi SE, et al. Primary Angle Closure Preferred Practice Pattern® Guidelines. Ophthalmology. 2016; 123 (1): p.P1-P40.doi: 10.1016/j.ophtha.2015.10.049 . | Open in Read by QxMD
  2. Razeghinejad MR, Myers JS. Contemporary approach to the diagnosis and management of primary angle-closure disease. Surv Ophthalmol. 2018; 63 (6): p.754-768.doi: 10.1016/j.survophthal.2018.05.001 . | Open in Read by QxMD
  3. Care of the Patient with Primary Angle Closure Glaucoma. Updated: January 1, 2001. Accessed: May 6, 2020.
  4. Angle-Closure Glaucoma. Updated: December 18, 2013. Accessed: March 17, 2017.
  5. Perera S, Amerasinghe N, Aung T. Angle closure glaucoma. Elsevier ; 2010: p. 193-199
  6. Pokhrel PK, Loftus SA. Ocular Emergencies. American Family Physician. 2007; 76: p.829–836.
  7. Tham Y-C, Li X, Wong TY, Quigley HA, Aung T, Cheng C-Y. Global prevalence of glaucoma and projections of glaucoma burden through 2040. Ophthalmology. 2014; 121 (11): p.2081-2090.doi: 10.1016/j.ophtha.2014.05.013 . | Open in Read by QxMD
  8. Edmunds B, Loh RA, Fenerty C, Papadopoulos M. Secondary Glaucoma: Glaucoma Associated with Acquired Conditions. American Academy of Ophthalmology. 2015.
  9. Sihota, Tandon R. Parsons' Diseases of the Eye. Elsevier India ; 2019
  10. Stamper RL, Lieberman MF, V. Drake M. Becker-Shaffer's Diagnosis and Therapy of the Glaucomas. Elsevier Health Sciences ; 2009
  11. Perkins ES. Hand-held applanation tonometer.. Br J Ophthalmol. 1965; 49 (11): p.591-593.doi: 10.1136/bjo.49.11.591 . | Open in Read by QxMD
  12. Arora R, Bellamy H, Austin M. Applanation tonometry: a comparison of the Perkins handheld and Goldmann slit lamp-mounted methods.. Clinical ophthalmology (Auckland, N.Z.). 2014; 8: p.605-10.doi: 10.2147/OPTH.S53544 . | Open in Read by QxMD
  13. Distelhorst JS, Hughes GM. Open-angle glaucoma.. Am Fam Physician. 2003; 67 (9): p.1937-44.
  14. Gupta D, Chen PP. Glaucoma.. Am Fam Physician. 2016; 93 (8): p.668-74.
  15. Gazzard G. The Severity and Spatial Distribution of Visual Field Defects in Primary Glaucoma. Arch Ophthal. 2002; 120 (12): p.1636.doi: 10.1001/archopht.120.12.1636 . | Open in Read by QxMD
  16. Murray D. Emergency management: angle-closure glaucoma.. Community eye health. 2018; 31 (103): p.64.
  17. Giaconi JA, Law SK, Nouri-Mahdavi K, Coleman AL, Caprioli J. Pearls of Glaucoma Management. Springer ; 2016
  18. Lam DS., Chua JK., Tham CC., Lai JS. Efficacy and safety of immediate anterior chamber paracentesis in the treatment of acute primary angle-closure glaucoma. Ophthalmology. 2002; 109 (1): p.64-70.doi: 10.1016/s0161-6420(01)00857-0 . | Open in Read by QxMD
  19. Reichman E. Emergency Medicine Procedures. McGraw-Hill ; 2013
  20. Cioboata M, Anghelie A, Chiotan C, Liora R, Serban R, Cornăcel C. Benefits of anterior chamber paracentesis in the management of glaucomatous emergencies.. Journal of medicine and life. 2014; 7 Spec No. 2: p.5-6.
  21. Flores-Sánchez BC, Tatham AJ. Acute angle closure glaucoma. Br J Hosp Med. 2019; 80 (12): p.C174-C179.doi: 10.12968/hmed.2019.80.12.c174 . | Open in Read by QxMD
  22. See JL, Aquino MC, Aduan J, Chew PT. Management of angle closure glaucoma.. Indian J Ophthalmol. 2011; 59 Suppl: p.S82-7.doi: 10.4103/0301-4738.73690 . | Open in Read by QxMD
  23. Spaeth GL, Idowu O, Seligsohn A, et al. The Effects of Iridotomy Size and Position on Symptoms Following Laser Peripheral Iridotomy. J Glaucoma. 2005; 14 (5): p.364-367.doi: 10.1097/01.ijg.0000177213.31620.02 . | Open in Read by QxMD
  24. Vijaya L, Asokan R, Panday M, George R. Is prophylactic laser peripheral iridotomy for primary angle closure suspects a risk factor for cataract progression? The Chennai Eye Disease Incidence Study.. Br J Ophthalmol. 2017; 101 (5): p.665-670.doi: 10.1136/bjophthalmol-2016-308733 . | Open in Read by QxMD
  25. Wang J, Barton K. Aqueous shunt implantation in glaucoma.. Taiwan journal of ophthalmology. 2017; 7 (3): p.130-137.doi: 10.4103/tjo.tjo_35_17 . | Open in Read by QxMD
  26. Ashar B, Miller R, Sisson S. Johns Hopkins Internal Medicine Board Review 2010-2011. Elsevier Health Sciences ; 2010
  27. Primary Open-Angle Glaucoma preferred practice pattern. Updated: November 1, 2015. Accessed: June 2, 2020.
  28. Jha B, Bhartiya S, Sharma R, Arora T, Dada T. Selective Laser Trabeculoplasty: An Overview.. Journal of current glaucoma practice. 2012; 6 (2): p.79-90.doi: 10.5005/jp-journals-10008-1111 . | Open in Read by QxMD
  29. Gazzard G, Konstantakopoulou E, Garway-Heath D, et al. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial. The Lancet. 2019; 393 (10180): p.1505-1516.doi: 10.1016/s0140-6736(18)32213-x . | Open in Read by QxMD
  30. Ang M, Tham CC, Sng CCA. Selective laser trabeculoplasty as the primary treatment for open angle glaucoma: time for change?. Eye. 2019; 34 (5): p.789-791.doi: 10.1038/s41433-019-0625-6 . | Open in Read by QxMD
  31. Understand Your Glaucoma Diagnosis. Updated: September 6, 2012. Accessed: March 17, 2017.
  32. Johnstone MA. Intraocular pressure regulation: Findings of pulse-dependent trabecular meshwork motion lead to unifying concepts of intraocular pressure homeostasis. J Ocul Pharmacol Ther. 2014; 30 (2-3): p.88-93.doi: 10.1089/jop.2013.0224 . | Open in Read by QxMD
  33. Intraocular Pressure. Updated: January 1, 2017. Accessed: February 21, 2018.
  34. Dabasia PL, Edgar DF, Lawrenson JG. Methods of measurement of the anterior chamber angle Part 2: Screening for angle closure and angle closure glaucoma. Optometry in Practice. 2013; 14 (4): p.147-154.
  35. Jacobs DS. Open-angle glaucoma: Treatment. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: September 30, 2016. Accessed: February 17, 2017.
  36. $SLT or Drops? Take Your Pick.
  37. Weizer JS. Angle-closure glaucoma. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: December 22, 2015. Accessed: February 17, 2017.
  38. Freedman J. Acute Angle-Closure Glaucoma. Acute Angle-Closure Glaucoma. New York, NY: WebMD. Updated: August 22, 2016. Accessed: February 17, 2017.
  39. Trattler W, Kaiser P, Friedman N. Review of Ophthalmology. Elsevier Saunders ; 2012
  40. Are You at Risk For Glaucoma?. Updated: January 13, 2011. Accessed: March 17, 2017.
  41. Biggerstaff KS. Primary Open-Angle Glaucoma. Primary Open-Angle Glaucoma. New York, NY: WebMD. Updated: September 15, 2016. Accessed: March 17, 2017.
  42. Jacobs DS. Open-angle glaucoma: Epidemiology, clinical presentation, and diagnosis. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: January 22, 2016. Accessed: March 17, 2017.
  43. Rhee DJ. Drug-Induced Glaucoma. Drug-Induced Glaucoma. New York, NY: WebMD. Updated: July 29, 2014. Accessed: March 17, 2017.
  44. Zhou M, Wang W, Huang W, Zhang X. Diabetes mellitus as a risk factor for open-angle glaucoma: A systematic review and meta-analysis. PLoS ONE. 2014; 9 (8): p.e102972.doi: 10.1371/journal.pone.0102972 . | Open in Read by QxMD
  45. Bigger JF. Glaucoma with elevated episcleral venous pressure. South Med J. 1975; 68 (11): p.1444-1448.
  46. Angle-Closure Glaucoma. Updated: October 1, 2019. Accessed: November 25, 2019.
  47. Acute Closed Angle Glaucoma. Updated: January 1, 2019. Accessed: November 25, 2019.
  48. Gorbaty JD, Hsu JE, Gee AO. Classifications in Brief: Rockwood Classification of Acromioclavicular Joint Separations. Clinical Orthopaedics and Related Research®. 2016; 475 (1): p.283-287.doi: 10.1007/s11999-016-5079-6 . | Open in Read by QxMD
  49. Lee TL, Yuxin Ng J, Nongpiur ME, Tan WJ, Aung T, Perera SA. Intraocular pressure spikes after a sequential laser peripheral iridotomy for angle closure.. J Glaucoma. 2014; 23 (9): p.644-8.doi: 10.1097/IJG.0b013e318285fdaa . | Open in Read by QxMD
  50. Mantravadi AV, Vadhar N. Glaucoma. Primary Care: Clinics in Office Practice. 2015; 42 (3): p.437-449.doi: 10.1016/j.pop.2015.05.008 . | Open in Read by QxMD
  51. Laser Trabeculoplasty: Questions in Clinical Practice. Updated: October 31, 2013. Accessed: May 19, 2020.
  52. Lusthaus J, Goldberg I. Current management of glaucoma. Med J Aust. 2019; 210 (4): p.180-187.doi: 10.5694/mja2.50020 . | Open in Read by QxMD
  53. Gupta S, Galpalli N, Agrawal S, Srivastava S, Saxena R. Recent advances in pharmacotherapy of glaucoma. Indian J Pharmacol. 2008; 40 (5): p.197.doi: 10.4103/0253-7613.44151 . | Open in Read by QxMD

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