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Hypotony

AI overview

Ocular hypotony, or ocular hypotension, or shortly hypotony, is the medical condition in which intraocular pressure (IOP) of the eye is very low.

Key points
  • Ocular hypotony is divided into statistical and clinical types
    source quote
    Ocular hypotony is divided into statistical and clinical types.
  • Statistical hypotony is defined as IOP less than 6.5 mm Hg
    source quote
    If intraocular pressure is low (less than 6.5 mm Hg) it is called statistical hypotony
  • Clinical hypotony is defined as reduced IOP causing decreased vision
    source quote
    if the reduced IOP causes a decrease in vision, it is called clinical
  • Hypotony may occur due to decreased production of aqueous humor or increased outflow
    source quote
    Hypotony may occur either due to decreased production of aqueous humor or due to increased outflow.
  • Decreased production can be caused by eye inflammation, medications, or proliferative vitreoretinopathy
    source quote
    Eye inflammation, medications including anti glaucoma drugs, or proliferative vitreoretinopathy causes decreased production.
Symptoms
  • Clinical hypotony presents with decreased vision
    source quote
    if the reduced IOP causes a decrease in vision, it is called clinical
Diagnosis
  • Normal IOP ranges between 10-20 mm Hg
    source quote
    Normal IOP ranges between 10–20 mm Hg.
  • The eye is considered hypotonous if IOP is ≤5 mm Hg (some sources say less than 6.5 mmHg)
    source quote
    The eye is considered hypotonous if the IOP is ≤5 mm Hg (some sources say IOP less than 6.5 mmHg)
Treatment
  • Treatment depends on the cause of the condition
    source quote
    Treatment of hypotony is depending on the cause of the condition.
  • If caused by an over filtering bleb, cycloplegia using atropine may be used
    source quote
    If the cause of hypotony is an over filtering bleb, cycloplegia using atropine may be used.
Red flags
  • Hypotony maculopathy is a complication caused by very low IOP
    source quote
    Hypotony maculopathy is another complication caused by very low IOP.
AI-synthesized from the Wikipedia article “Hypotony”. Not medical advice. Verify source →

Ocular hypotony, or ocular hypotension, or shortly hypotony, is the medical condition in which intraocular pressure (IOP) of the eye is very low.

Ocular hypotony is divided into statistical and clinical types. If intraocular pressure is low (less than 6.5 mm Hg) it is called statistical hypotony, and if the reduced IOP causes a decrease in vision, it is called clinical.[1]

Complications

Decreased IOP may lead to phthisis bulbi.[2] Hypotony maculopathy is another complication caused by very low IOP.[3]

Hypotony may occur either due to decreased production of aqueous humor or due to increased outflow. Hypotony has many causes including post-surgical wound leak from the eye, chronic inflammation within the eye including iridocyclitis, hypoperfusion, tractional ciliary body detachment or retinal detachment.[4] Eye inflammation, medications including anti glaucoma drugs, or proliferative vitreoretinopathy causes decreased production.[5] Increased outflow or aqueous loss may occur following a glaucoma surgery, trauma, cyclodialysis cleft or retinal detachment.[5]

Normal IOP ranges between 10–20 mm Hg.[6] The eye is considered hypotonous if the IOP is ≤5 mm Hg (some sources say IOP less than 6.5 mmHg).[7][2]

Treatment of hypotony is depending on the cause of the condition.[5] Chronic ocular hypotony may be treated with intraocular injection of sodium hyaluronate.[8] If the cause of hypotony is an over filtering bleb, cycloplegia using atropine may be used.[7]

  1. ↑ Thomas, Merina; Vajaranant, Thasarat S.; Aref, Ahmad A. (December 2015). "Hypotony Maculopathy: Clinical Presentation and Therapeutic Methods". Ophthalmology and Therapy. 4 (2): 79–88. doi:10.1007/s40123-015-0037-z. ISSN 2193-8245. PMC 4675727. PMID 26253854.
  2. 1 2 Schmack, Ingo; Völcker, Hans E; Grossniklaus, Hans E (1 January 2010). "Chapter 54 - Phthisis bulbi". Ocular Disease. W.B. Saunders. pp. 415–423. ISBN 978-0-7020-2983-7.
  3. ↑ "Hypotony Maculopathy - EyeWiki". eyewiki.aao.org.
  4. ↑ "Ocular Hypotony: Background, Pathophysiology, Epidemiology". 19 July 2021.
  5. 1 2 3 Fine, Howard F.; Biscette, O'neil; Chang, Stanley; Schiff, William M. (January 2007). "Ocular hypotony: a review". Comprehensive Ophthalmology Update. 8 (1): 29–37. ISSN 1527-7313. PMID 17394757.
  6. ↑ "Eye Pressure". American Academy of Ophthalmology. 19 January 2018.
  7. 1 2 N.Y, Valerie Trubnik, MD, FACS, Mineola. "Managing Hypotony After Trabeculectomy". www.reviewofophthalmology.com.{{cite web}}: CS1 maint: multiple names: authors list (link)
  8. ↑ Küçükerdönmez, C.; Beutel, J.; Bartz-Schmidt, K. U.; Gelisken, F. (1 February 2009). "Treatment of chronic ocular hypotony with intraocular application of sodium hyaluronate". British Journal of Ophthalmology. 93 (2): 235–239. doi:10.1136/bjo.2008.143834. ISSN 0007-1161. PMID 18829633. S2CID 36520175.