Eye surgery

Eye surgery
Intervention
Eye surgery in the Middle Ages.
ICD-10-PCS	08
ICD-9-CM	08-16
MeSH
OPS-301 code:	5-08...5-16

Eye surgery, also known as ocular surgery, is surgery performed on the eye or its adnexa, typically by an ophthalmologist.^[1] The eye is a fragile organ, and requires extreme care before, during, and after a surgical procedure. An expert eye surgeon is responsible for selecting the appropriate surgical procedure for the patient, and for taking the necessary safety precautions.

Preparation and precautions

Since the eye is heavily supplied by nerves, anesthesia is essential. Local anesthesia is most commonly used. Topical anesthesia using lidocaine topical gel are often used for quick procedures. Since topical anesthesia requires cooperation from the patient, general anesthesia is often used for children, traumatic eye injuries, major orbitotomies and for apprehensive patients. The physician administering anesthesia monitors the patient's cardiovascular status. Sterile precautions are taken to prepare the area for surgery and lower the risk of infection. Sterile precautions include the use of antiseptics like povidone-iodine, sterile drapes, gowns and gloves.

Laser eye surgery

Although 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).^[2] Laser eye surgery or laser corneal surgery is a medical procedure that uses a laser to reshape the surface of the eye. This is done to correct myopia (short-sightedness), hypermetropia (long sightedness) and astigmatism (uneven curvature of the eye's surface). It is important to note that refractive surgery is not compatible with everyone, and rarely people may find that eyewear is still needed after surgery.^[3]

Cataract surgery

Cataract surgery, using a temporal approach phacoemulsification probe (in right hand) and "chopper"(in left hand) being done under operating microscope at a Navy medical center

A cataract is an opacification or cloudiness of the eye's crystalline lens due to aging, disease, or trauma that typically prevents light from forming a clear image on the retina. If visual loss is significant, surgical removal of the lens may be warranted, with lost optical power usually replaced with a plastic intraocular lens (IOL). Owing to the high prevalence of cataracts, cataract extraction is the most common eye surgery. Rest after surgery is recommended.^[4]

Glaucoma surgery

Glaucoma is a group of diseases affecting the optic nerve that results in vision loss and is frequently characterized by raised intraocular pressure (IOP). There are many types of glaucoma surgery, and variations or combinations of those types, that facilitate the escape of excess aqueous humor from the eye to lower intraocular pressure, and a few that lower IOP by decreasing the production of aqueous humor.

Canaloplasty

Canaloplasty is an advanced, nonpenetrating procedure designed to enhance drainage through the eye’s natural drainage system to provide sustained reduction of IOP. Canaloplasty utilizes microcatheter technology in a simple and minimally invasive procedure. To perform a canaloplasty, an Ophthalmologist creates a tiny incision to gain access to a canal in the eye. A microcatheter circumnavigates the canal around the iris, enlarging the main drainage channel and its smaller collector channels through the injection of a sterile, gel-like material called viscoelastic. The catheter is then removed and a suture is placed within the canal and tightened. By opening up the canal, the pressure inside the eye can be reduced. Long-term results are available, published in the Journal of Cataract and Refractive Surgery.^[5][6][7][8]

Refractive surgery

Refractive surgery aims to correct errors of refraction in the eye, reducing or eliminating the need for corrective lenses

• Keratomilleusis is a method of reshaping the cornea surface to change its optical power. A disc of cornea is shaved off, quickly frozen, lathe-ground, then returned to its original power.
• Automated lamellar keratoplasty (ALK)
• Laser assisted in-situ keratomileusis (LASIK)^[9]
  • IntraLASIK
• Laser assisted sub-epithelial keratomileusis (LASEK), aka Epi-LASIK
• Photorefractive keratectomy (PRK)^[10]
• Laser thermal keratoplasty (LTK)
• Conductive keratoplasty (CK) uses radio frequency waves to shrink corneal collagen. It is used to treat mild to moderate hyperopia.^[9]
• Limbal relaxing incisions (LRI) to correct minor astigmatism
• Astigmatic keratotomy (AK), aka Arcuate keratotomy or Transverse keratotomy
• Radial keratotomy (RK)
• Mini Asymmetric Radial Keratotomy (M.A.R.K.) it consists of a series of microincisions, always made with a diamond knife, designed to cause a controlled cicatrisation of the cornea, which changes its thickness and shape. This procedure, if done properly, is able to correct the astigmatism and cure the first and second stage of the keratoconus, avoiding the need for a cornea transplant.^{[11][12][13][14]}
• Hexagonal keratotomy (HK)
• Epikeratophakia is the removal of the corneal epithelium and replacement with a lathe cut corneal button.^[15]
• Intracorneal rings (ICRs), or corneal ring segments (Intacs) ^[16]
• Implantable contact lenses
• Presbyopia reversal
• Anterior ciliary sclerotomy (ACS)
• Laser reversal of presbyopia (LRP),J.T. Lin, US Pat # 6,258,082 (2001).
• Scleral expansion bands (SEB),
• The Karmra inlay^[17] The Karmra inlay received the 2005 European CE mark. The 1.6 mm inlay is placed inside the cornea and has a small aperture that gives clearer vision at intermediate and near distances. TGA registration is expected sometime in 2011.
• Scleral reinforcement surgery for the mitigation of degenerative myopia

Corneal surgery

Corneal surgery includes most refractive surgery as well as the following:

• Corneal transplant surgery, is used to remove a cloudy/diseased cornea and replace it with a clear donor cornea.^[15]
• Penetrating keratoplasty (PK)
• Keratoprosthesis(KPro)
• Phototherapeutic keratectomy (PTK)^[18]
• Pterygium excision^[19]
• Corneal tattooing
• Osteo-Odonto-Keratoprosthesis (OOKP), in which support for an artificial cornea is created from a tooth and its surrounding jawbone.^[20] This is a still-experimental procedure used for patients with severely damaged eyes, generally from burns.^[21]

Vitreo-retinal surgery

Vitrectomy.

Vitreo-retinal surgery includes the following

• Vitrectomy^[22]
  • Anterior vitrectomy is the removal of the front portion of vitreous tissue. It is used for preventing or treating vitreous loss during cataract or corneal surgery, or to remove misplaced vitreous in conditions such as aphakia pupillary block glaucoma.
  • Pars plana vitrectomy (PPV), or trans pars plana vitrectomy (TPPV), is a procedure to remove vitreous opacities and membranes through a pars plana incision. It is frequently combined with other intraocular procedures for the treatment of giant retinal tears, tractional retinal detachments, and posterior vitreous detachments.^[23]
• Pan retinal photocoagulation (PRP) is a type of photocoagulation therapy used in the treatment of diabetic retinopathy.^[24]
• Retinal detachment repair
  • Ignipuncture is an obsolete procedure that involves cauterization of the retina with a very hot pointed instrument.^[25]
  • A scleral buckle is used in the repair of a retinal detachment to indent or "buckle" the sclera inward, usually by sewing a piece of preserved sclera or silicone rubber to its surface.^[26]
  • Laser photocoagulation, or photocoagulation therapy, is the use of a laser to seal a retinal tear.^[24]
  • Pneumatic retinopexy
  • Retinal cryopexy, or retinal cryotherapy, is a procedure that uses intense cold to induce a chorioretinal scar and to destroy retinal or choroidal tissue.^[27]
• Macular hole repair
• Partial lamellar sclerouvectomy^[28]
• Partial lamellar sclerocyclochoroidectomy
• Partial lamellar sclerochoroidectomy
• Posterior sclerotomy is an opening made into the vitreous through the sclera, as for detached retina or the removal of a foreign body [1].
• Radial optic neurotomy
• macular translocation surgery
  • through 360 degree retinotomy
  • through scleral imbrication technique
• Dexmedetomidine Versus Propofol in Vitreoretinal Surgery Alpha2 adrenergic receptor agonist have been used increasingly as a new armamentarium to provide sedative/hypnotic, analgesic, anxiolytic and sympatholytic effects in the perioperative settings. Dexmedetomidine, a selective and specific alpha2- adrenoceptor agonist has unique properties that makes it an almost ideal sedative drug for monitored anesthesia care in procedures under local or regional block. Unlike other drugs use for sedation, dexmedetomidine induces sedation that is similar to natural sleep (readily arousable) without causing respiratory depression. It attenuates the stress-induced sympathoadrenal response seen with laryngoscopy and intubation. It has anesthetic and opioid sparing effects, hence it may be a useful adjunct to general anesthesia and monitored anesthesia care in patients susceptible to narcotic induced respiratory depression. Another unique property of dexmedetomidine is that its sedative effect is reversible with Atipamezole. A previous study wherein dexmedetomidine has been used in procedures under local and regional block had shown that it provides effective sedation and better operating condition without significant respiratory depression. As a supplement to general anesthesia, it has been shown to provide stable hemodynamics. However, it is associated with some adverse events such as hypertension, hypotension and bradycardia, these commonly occur during bolus administration of the recommended dose of 1 ug/kg. Post-operatively it can cause nausea and vomiting. Vitreoretinal surgery requires either an injection of local anesthetic within the muscle cone (retrobulbar block),or into the periorbital space (peribulbar block). This can be done individually or in combination. This surgery can also be done under a safer technique of retrobulbar block that is given using a sub-tenon's approach through a snip peritomy; a blunt cannula can be used with this technique mitigating the complications of retrobulbar hemorrhage or inadvertent injection into the optic nerve sheath or perforation of the globe using a sharp needle. The anesthetic goal is to provide an immobile and uncongested operative field. Hemodynamic stability of the patient is also important since some patients that require this procedure are elderly with co-morbid conditions such as hypertension, diabetes mellitus and CAD. In our study we would like to investigate if Dexmedetomidine alone and in a reduced dose can prevent or reduce the incidence of adverse effects, provide hemodynamic and respiratory stability, provide adequate sedation with patient and surgeon satisfaction and compare it with Propofol.^[29]

Eye muscle surgery

Isolating the inferior rectus muscle

Disinserting the medial rectus muscle, after pre-placing vicryl suture

With approximately 1.2 million procedures each year, extraocular muscle surgery is the third most common eye surgery in the United States [2].

• Eye muscle surgery typically corrects strabismus and includes the following^[30] [3]:
  • Loosening / weakening procedures
    • Recession involves moving the insertion of a muscle posteriorly towards its origin.
    • Myectomy
    • Myotomy
    • Tenectomy
    • Tenotomy
  • Tightening / strengthening procedures
    • Resection
    • Tucking
    • Advancement is the movement of an eye muscle from its original place of attachment on the eyeball to a more forward position.
  • Transposition / repositioning procedures
  • Adjustable suture surgery is a method of reattaching an extraocular muscle by means of a stitch that can be shortened or lengthened within the first post-operative day, to obtain better ocular alignment [4].

Oculoplastic surgery

Oculoplastic surgery, or oculoplastics, is the subspecialty of ophthalmology that deals with the reconstruction of the eye and associated structures. Oculoplastic surgeons perform procedures such as the repair of droopy eyelids (blepharoplasty)[5], repair of tear duct obstructions, orbital fracture repairs, removal of tumors in and around the eyes, and facial rejuvenation procedures including laser skin resurfacing, eye lifts, brow lifts, and even facelifts. Common procedures are:

Eyelid surgery

• Blepharoplasty (Eyelift)
  • Blepharoplasty is plastic surgery of the eyelids to remove excessive skin or subcutaneous fat.^[31]
    • Asian blepharoplasty
• Ptosis repair for droopy eyelid
  • Ectropion repair [6]
• Entropion repair
• Canthal resection
  • A canthectomy is the surgical removal of tissue at the junction of the upper and lower eyelids.^[32]
  • Cantholysis is the surgical division of the canthus.^[32]
  • Canthopexy
  • A canthoplasty is plastic surgery at the canthus.^[32]
  • A canthorrhaphy is suturing of the outer canthus to shorten the palpebral fissure.^[32]
  • A canthotomy is the surgical division of the canthus, usually the outer canthus.^[32]
    • A lateral canthotomy is the surgical division of the outer canthus.
• Epicanthoplasty
• Tarsorrhaphy is a procedure in which the eyelids are partially sewn together to narrow the opening (i.e. palpebral fissure).

Orbital surgery

• Orbital reconstruction / Ocular prosthetics (False Eyes)
• Orbital decompression for Grave's Disease. Grave's Disease is a condition (often associated with over-active thyroid problems) in which the eye muscles swell. Because the eye socket is bone, there is nowhere for the swelling to be accommodated and as a result the eye is pushed forward into a protruded position. In some patients this is very pronounced. Orbitial decompression involves removing some bone from the eye socket to open up one or more sinuses and so make space for the swollen tissue and allowing the eye to move back into normal position.

Other oculoplastic surgery

• Botox injections
• Ultrapeel Microdermabrasion
• Endoscopic forehead and browlift
• Face lift (Rhytidectomy)
• Liposuction of the face and neck
• Browplasty^[33]

Surgery involving the lacrimal apparatus

• A dacryocystorhinostomy (DCR) or dacryocystorhinotomy is a procedure to restore the flow of tears into the nose from the lacrimal sac when the nasolacrimal duct does not function.^[32][34]
• Canaliculodacryocystostomy is a surgical correction for a congenitally blocked tear duct in which the closed segment is excised and the open end is joined to the lacrimal sac.^[32][35]
• Canaliculotomy involves slitting of the lacrimal punctum and canaliculus for the relief of epiphora^[32]
• A dacryoadenectomy is the surgical removal of a lacrimal gland.^[32]
• A dacryocystectomy is the surgical removal of a part of the lacrimal sac.^[32]
• A dacryocystostomy is an incision into the lacrimal sac, usually to promote drainage.^[32]
• A dacryocystotomy is an incision into the lacrimal sac.^[32]

Eye removal

• An enucleation is the removal of the eye leaving the eye muscles and remaining orbital contents intact.^[36]
• An evisceration is the removal of the eye's contents, leaving the scleral shell intact. Usually performed to reduce pain in a blind eye.^[37]
• An exenteration is the removal of the entire orbital contents, including the eye, extraocular muscles, fat, and connective tissues; usually for malignant orbital tumors.^[38]

Other surgery

Many of these described procedures are historical and are not recommended due to a risk of complications. Particularly, these include operations done on ciliary body in an attempt to control glaucoma, since highly safer surgeries for glaucoma, including lasers, non-penetrating surgery, guarded filtration surgery and seton valve implants have been invented.

• A ciliarotomy is a surgical division of the ciliary zone in the treatment of glaucoma.^[32]
• A ciliectomy is 1) the surgical removal of part of the ciliary body, or 2) the surgical removal of part of a margin of an eyelid containing the roots of the eyelashes.^[32]
• A ciliotomy is a surgical section of the ciliary nerves.^[32]
• A conjunctivoanstrostomy is an opening made from the inferior conjuctival cul-de-sac into the maxillary sinus for the treatment of epiphora.^[32]
• Conjuctivoplasty is plastic surgery of the conjunctiva.^[32]
• A conjunctivorhinostomy is a surgical correction of the total obstruction of a lacrimal canaliculus by which the conjuctiva is anastomosed with the nasal cavity to improve tear flow.^[32]
• A corectomedialysis, or coretomedialysis, is an excision of a small portion of the iris at its junction with the ciliary body to form an artificial pupil.^[32]
• A corectomy, or coretomy, is any surgical cutting operation on the iris at the pupil.^[32]
• A corelysis is a surgical detachment of adhesions of the iris to the capsule of the crystalline lens or cornea.^[32]
• A coremorphosis is the surgical formation of an artificial pupil.^[32]
• A coreplasty, or coreoplasty, is plastic surgery of the iris, usually for the formation of an artificial pupil.^[32]
• A coreoplasy, or laser pupillomydriasis, is any procedure that changes the size or shape of the pupil.^[37]
• A cyclectomy is an excision of portion of the ciliary body.^[32]
• A cyclotomy, or cyclicotomy, is a surgical incision of the ciliary body, usually for the relief of glaucoma.^[32]
• A cycloanemization is a surgical obliteration of the long ciliary arteries in the treatment of glaucoma.^[32]
• An iridectomesodialsys is the formation of an artificial pupil by detaching and excising a portion of the iris at its periphery.^[32]
• An iridodialysis, sometimes known as a coredialysis, is a localized separation or tearing away of the iris from its attachment to the ciliary body.^[32][37]
• An iridencleisis, or corenclisis, is a surgical procedure for glaucoma in which a portion of the iris is incised and incarcerated in a limbal incision.^[32] (Subdivided into basal iridencleisis and total iridencleisis.^[39])
• An iridesis is a surgical procedure in which a portion of the iris is brought through and incarcerated in a corneal incision in order to reposition the pupil.^[32][7]
• An iridocorneosclerectomy is the surgical removal of a portion of the iris, the cornea, and the sclera.^[32]
• An iridocyclectomy is the surgical removal of the iris and the ciliary body.^[32]
• An iridocystectomy is the surgical removal of a portion of the iris to form an artificial pupil.^[32]
• An iridosclerectomy is the surgical removal of a portion of the sclera and a portion of the iris in the region of the limbus for the treatment of glaucoma.^[32]
• An iridosclerotomy is the surgical puncture of the sclera and the margin of the iris for the treatment of glaucoma.^[32]
• A rhinommectomy is the surgical removal of a portion of the internal canthus.^[32]
• A trepanotrabeculectomy is used in the treatment of chronic open and chronic closed angle glaucoma.^[39]

See also

• LASIK
• Ophthalmology
• Topical anesthetic

References