| Homepage | Imprint |
|
||
 |
Eye surgeryEye surgery, also known as ophthalmic surgery or ocular surgery, is a surgical procedureperformed on the eyeor its adnexatypically by an ophthalmologist[{{fullurl:Template:FULLPAGENAME}}#endnote_Ophthalmologic_surgery].
Laser surgery and incisional surgeryAlthough the terms "laser eye surgery" and "refractive surgery" are commonly used as if they were interchangeable, this is not the case. Lasers may be used to treat nonrefractive conditions (e.g. to seal a retinal tear), while radial keratotomyis an example of refractive surgery without the use of a laser. Types of eye surgeriesCataract surgery
A cataractis an opacification or cloudiness of the eye's crystalline lensdue to aging, disease, or trauma that typically prevents light from forming a clear image on the retina. If visual lossis significant, surgical removal of the lens may be warranted, with lost optical powerusually replaced with a plastic intraocular lens(IOL). Due to the high prevalence of cataracts, cataract extraction is the most common eye surgery [{{fullurl:Template:FULLPAGENAME}}#endnote_Uhr]. The two main types of cataract extraction are intracapsular cataract extraction (ICCE) and extracapsular cataract extraction (ECCE). Intracapsular cataract extraction involves the removal of the lens and the surrounding lens capsule in one piece. The procedure has a relatively high rate of complications due to the large incision required and pressure placed on the vitreous body, thus is rarely performed in countries where operating microscopes and high-technology equipment are readily available [{{fullurl:Template:FULLPAGENAME}}#endnote_ECCE]. Cryoextraction is a form of ICCE that freezes the lens with a cryogenic substance such as liquid nitrogen[{{fullurl:Template:FULLPAGENAME}}#endnote_Cryotherapy]. Although it is now used primarily for the removal of subluxated lenses, it was the favored form of cataract extraction from the late 1960s to the early 1980s [{{fullurl:Template:FULLPAGENAME}}#endnote_Meadow]. Extracapsular cataract extraction involves the removal of the lens while the elastic lens capsule is left partially intact to allow implantation of an intraocular lens [{{fullurl:Template:FULLPAGENAME}}#endnote_ECCE]. There are two main types of extracapsular surgery: conventional ECCE and phacoemulsification. Conventional extracapsular cataract extraction involves manual expression of the lens through an incision made in the corneaor sclera. Although it requires a larger incision and the use of stitches, the conventional method is indicated for patients with very hard cataracts or weak corneal epithelial tissue. Phacoemulsification involves the use of an ultrasonic vibrating handpiece to shatter and break up a cataract, thus making it easier to remove. Because a smaller incision is required, few or no stitches are needed and the patient's recovery time is usually shorter. [{{fullurl:Template:FULLPAGENAME}}#endnote_Phacoemulsification][{{fullurl:Template:FULLPAGENAME}}#endnote_ECCE]. A capsulotomy is a procedure to open a portion of the lens capsule. An anterior capsulotomy refers to the opening of the front portion of the lens capsule, whereas a posterior capsulotomy refers to the opening of the back portion of the lens capsule. In an extracapsular surgery, the surgeon performs an anterior capsulotomy, or capsulorhexis, to create an opening through which the lens nucleus can be removed and the intraocular lens implant inserted. An opacification or clouding of the posterior lens capsule frequently occurs in those who have had an extracapsular cataract extraction procedure, therefore, a laser posterior capsulotomy, or YAG lasercapsulotomy, is used to clear the back implant surface [{{fullurl:Template:FULLPAGENAME}}#endnote_Capsulotomy]. (Whereas a capsulotomy is the creation of an opening in the lens capsule, a capsulectomy is the acutal removal of lens capsule tissue.) Glaucoma surgeryGlaucomais a group of diseases affecting the optic nervethat results in vision lossand is frequently characterized by raised intraocular pressure(IOP). There are many glaucoma surgeries, and variations or combinations of those surgeries, that facilitate the escape of excess aqueous humorfrom the eye to lower intraocular pressure, and a few that lower IOP by decreasing the production of aqueous. Procedures that facilitate outflow of aqueous humorLaser trabeculoplasty A trabeculoplasty is a modification of the trabecular meshwork. Laser trabeculoplasty (LTP) is the application of a laser beam to burn areas of the trabecular meshwork, located near the base of the iris, to increase fluid outflow. LTP is used in the treatment of various open-angle glaucomas [{{fullurl:Template:FULLPAGENAME}}#endnote_LTP]. The two types of laser trabeculoplasty are argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT). As its name suggests, argon laser trabeculoplasty uses an argon laserto create tiny burns on the trabecular meshwork [{{fullurl:Template:FULLPAGENAME}}#endnote_ALT]. Selective laser trabeculoplasty is newer technology that uses a Nd:YAG laserto target specific cells within the trabecular meshwork and create less thermal damage than ALT [{{fullurl:Template:FULLPAGENAME}}#endnote_SLT1][{{fullurl:Template:FULLPAGENAME}}#endnote_SLT2]. Iridotomy An iridotomy involves making puncture-like openings through the iriswithout the removal of iris tissue. Performed either with standard surgical instruments or a laser, it is typically used to decrease intraocular pressure in patients with angle-closure glaucoma. A laser peripheral iridotomy (LPI) is the application of a laser beam to selectively burn a hold through the iris near its base. LPI may be performed with either an argon laser or Nd:YAG laser [{{fullurl:Template:FULLPAGENAME}}#endnote_LPI1][{{fullurl:Template:FULLPAGENAME}}#endnote_LPI2]. Iridectomy An iridectomy, or surgical iridectomy, involves the removal of a portion of iris tissue [{{fullurl:Template:FULLPAGENAME}}#endnote_Iridectomy]. A basal iridectomy is the removal of iris tissue from the far periphery, near the iris root; a peripheral iridectomy is the removal of iris tissue at the periphery; and a sector iridectomy is the removal of a wedge-shaped section of iris that extends from the pupil margin to the iris root, leaving a keyhole-shaped pupil. Filtering procedures: penetrating vs. non-penetrating Filtering surgeries are the mainstay of surgical treatment to control intraocular pressure [{{fullurl:Template:FULLPAGENAME}}#endnote_Jacobi]. An anterior sclerotomy or sclerostomy is used to gain access to the inner layers of the eye [1] [2][3]in order to create a drainage channel from the anterior chamber to the external surface of the eye under the conjunctiva, allowing aqueous to seep into a bleb from which it is slowly absorbed. Filtering procedures are typically divided into either penetrating or non-penetrating types depending upon whether an intraoperative entry into the anterior chamber occurs [4][5]. Penetrating filtering surgeries are further subdivided into guarded filtering procedures, also known as protected, subscleral, or partial thickness filtering procedures (in which the surgeon sutures a scleral flap over the sclerostomy site [6]), and full thickness procedures [7]. Trabeculectomy is a guarded filtering procedure that removes of part of the trabecular meshwork [{{fullurl:Template:FULLPAGENAME}}#endnote_Trabeculectomy] [8]. Full thickness procedures include sclerectomy, posterior lip sclerectomy (in which the surgeon completely excises the sclera on the area of the sclerostomy [9]), trephination, thermal sclerostomy (Scheie procedure), iridenclesis, and sclerostomy (including conventional sclerostomy and enzymatic sclerostomy) [10][11]. Non-penetrating filtering surgeries do not penetrate or enter the eye's anterior chamber[12][13]. There are two types of non-penetrating surgeris: Bleb-forming and viscocanalostomy [14][15]. Bleb forming procedures include ab externo trabeculectomy and deep sclerectomy[16]. Ab externo trabeculectomy (AET) involves cutting from outside the eye inward to reach Schlemm's canal, the trabecular meshwork, and the anterior chamber. Also known as non-penetrating trabeculectomy (NPT), it is an ab externo (from the outside), major ocular procedure in which Schlemm's canal is surgically exposed by making a large and very deep scleral flap. The inner wall of Schlemm's canal is stripped off after surgically exposing the canal [17]. Deep sclerectomy, also known as nonpenetrating deep sclerectomy (PDS) or nonpenetrating trabeculectomy is a filtering surgery where the internal wall of Schlemm's canal is excised, allowing subconjunctival filtration without actually entering the anterior chamber [18]; it is commonly performed with the Aquaflow® collagen wick [19]. Viscocanalostomy is also an ab externo, major ocular procedure in which Schlemm's canal is surgically exposed by making a large and very deep scleral flap. In the VC procedure, Schlemm's canal is cannulated and viscoelastic substance injected (which dilates Schlemm's canal and the aqueous collector channels)[20]. Other surgical procedures Goniotomy and trabeculotomy are similar simple and directed techniques of microsurgical dissection with mechanical disruption of the trabecular meshwork [21][22][23]. Gonotomy procedures include surgical goniotomy and laser goniotomy. A surgical goniotomy involves cutting the fibers of the trabecular meshwork to allow aqueous fluid to flow more freely from the eye [24][25][{{fullurl:Template:FULLPAGENAME}}#endnote_Goniotomy]. Laser goniotomy is also known as goniophotoablation and laser trabecular ablation [26]. In many patients suffering from congenital glaucoma, the cornea is not clear enough to visualize the anterior chamber angle. Although an endoscopic goniotomy, which employs an endoscope to view the anterior chamber angle, may be performed [27], a trabeculotomy which accesses the angle from the exterior surface of the eye, thereby eliminating the need for a clear cornea, is usually preferred in these instances. A specially designed probe is used to tear through the trabecular meshwork to open it and allow fluid flow [28].Video Tube-shunt surgery or drainage implant surgery involves the placement of a tube to facilitate aqueous outflow from the anterior chamber [{{fullurl:Template:FULLPAGENAME}}#endnote_Tube-shunt] [29][30]. Trabeculopuncture uses a Q switched Nd:YAG laser to punch small holes in the trabecular meshwork with [31][32][33]. Goniocurretage is an "ab interno" (from the inside) procedure that used an instrument "to scrape pathologically altered trabecular meshwork off the scleral sulcus" [34][35][36]. A surgical cyclodialysis is a rarely used procedure that aims to separate the ciliary body from the sclera. Procedures that decrease production of aqueous humorCertain cells within the eye's ciliary bodyproduce aqueous humor. A ciliary destructive or cyclodestructive procedure is one that aims to destroy those cells in order to reduce intraocular pressure [37]. Cyclocryotherapy, or cyclocryopexy, uses a freezing probe [38]. Cyclophotocoagulation, also known as transscleral cyclophotocoagulation, ciliary body ablation,[39], cyclophotoablation [40], and cyclophototherapy [41], uses a laser.[{{fullurl:Template:FULLPAGENAME}}#endnote_Cyclophotocoagulation][{{fullurl:Template:FULLPAGENAME}}#endnote_Trabeculectomy]. Refractive surgery
Corneal surgery
Vitreo-retinal surgery
Eye muscle surgeryWith approximately 1.2 million procedures each year, extraocular musclesurgery is the third most common eye surgery in the United States [46].
Oculoplastic surgery
References
^ Jacobi PC, Dietlein TS, Krieglstein GK. "Technique of goniocurettage: a potential treatment for advanced chronic open angle glaucoma." Br J Ophthalmol. 1997 Apr;81(4):302-7. PMID 9215060
See also
External links
Categories: Surgery| Ophthalmology| Medical treatment stubs
|
