Iridectomy Explained

Iridectomy
Synonyms:	Surgical iridectomy

An iridectomy, also known as a surgical iridectomy or corectomy, is the surgical removal of part of the iris.^{[1] [2]} These procedures are most frequently performed in the treatment of closed-angle glaucoma and iris melanoma.^[2]

Comparison with Nd:YAG laser iridotomy

In acute angle-closure glaucoma cases, surgical iridectomy has been superseded by iridotomy, because the laser procedure is much safer. Opening the globe for a surgical iridectomy in a patient with high intraocular pressure greatly increases the risk of suprachoroidal hemorrhage, with potential for associated expulsive hemorrhage. Nd:YAG laser iridotomy avoids such a catastrophe by using a laser to create a hole in the iris, which facilitates flow of aqueous humor from the posterior to the anterior chamber of the eye.^[3]

Current indications

Surgical iridectomy is commonly indicated and performed in the following cases:

• Cataract surgery in a glaucoma patient
• Combined procedure for cataract and glaucoma
• Acute closed-angle glaucoma
• Posterior capsular tears with vitreous loss
• Implantation of anterior chamber IOL.
• Vitreoretinal procedure involving injection of silicone oil. The location of the iridectomy in such cases is at 6 o'clock, as opposed to routine iridectomy done at 11 to 1 o'clock. This is because silicone oil is less dense than water.
• Iris trauma

Types

• An antiphogistic iridectomy is the surgical removal of part of the iris to reduce intraocular pressure in inflammatory conditions of the eye.^[1]
• A basal iridectomy is an iridectomy which includes the root of the iris.^[1]
• An optical iridectomy is the surgical removal of part of the iris to enlarge the existing pupil, or to form an artificial pupil, when the natural pupil is ineffectual.^[1]
• A peripheral iridectomy is the surgical removal of a portion of the iris in the region of its root, leaving the pupillary margin and sphincter pupillae muscle intact.^[1] It is used in the treatment of glaucoma.^[2]
• A preliminary iridectomy, or preparatory iridectomy, is the surgical removal of part of the iris preceding cataract extraction.^[1] It facilitates the removal of the cataractous lens.^[2]
• A sector iridectomy, also known as a complete iridectomy or total iridectomy, is the surgical removal of a complete radial section of the iris extending from the pupillary margin to the root of the iris.^[1] A key-hole pupil is left by the removal of a wedge-shaped section of iris.^[4]
• A stenopeic iridectomy is the surgical removal of a narrow slit or a minute portion of the iris, leaving the sphincter pupillae muscle intact.^[1]
• A therapeutic iridectomy is the surgical removal of a portion of the iris for the cure or prevention of an ocular disease.^[1]

See also

• Eye surgery
• Glaucoma surgery
• List of surgeries by type

Notes and References

1. Cline D; Hofstetter HW; Griffin JR. Dictionary of Visual Science. 4th ed. Butterworth-Heinemann, Boston 1997.
2. http://www.surgeryencyclopedia.com/Fi-La/Iridectomy.html Surgery Encyclopedia - "Iridectomy."
3. Web site: Side Effects of Laser Iridotomy . Yvonne . Ou . University of California, San Francisco . 5 July 2021 . 23 February 2023 . www.brightfocus.org . 23 February 2023 . https://web.archive.org/web/20230223201055/https://www.brightfocus.org/glaucoma/article/side-effects-laser-iridotomy . live .
4. Cassin, B. and Solomon, S. Dictionary of Eye Terminology. Gainesville, Florida: Triad Publishing Company, 1990.