7 results
102 - Corneal transplantation
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- By C. Diane Song, Emory University, School of Medicine, Atlanta, GA, Enrique Garcia-Valenzuela, Emory University, School of Medicine, Atlanta, GA, G. Baker Hubbard III, Emory University, School of Medicine, Atlanta, GA, Thomas M. Aaberg, Sr., Emory University, School of Medicine, Atlanta, GA
- Edited by Michael F. Lubin, Emory University, Atlanta, Robert B. Smith, Emory University, Atlanta, Thomas F. Dodson, Emory University, Atlanta, Nathan O. Spell, Emory University, Atlanta, H. Kenneth Walker, Emory University, Atlanta
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- Book:
- Medical Management of the Surgical Patient
- Published online:
- 12 January 2010
- Print publication:
- 10 August 2006, pp 700-701
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Summary
Corneal transplant, also known as penetrating keratoplasty, has a 90% success rate as defined by clear grafts in 1 year. The primary indication for the procedure is a hazy or opaque cornea causing decrease in vision. The etiologies of corneal opacities include congenital defects, hereditary dystrophies, infection, and trauma. Occasionally, corneal transplants are performed simultaneously with cataract surgery, intraocular lens exchange, or with posterior segment surgery, depending on other conditions affecting vision. The procedure is not as common as lamellar keratoplasty, in which only the anterior surface of the cornea is grafted, leaving the posterior surface intact.
For most patients, the operation is performed on an outpatient basis under local anesthesia with monitored anesthesia care. Under special circumstances, a patient may require general anesthesia and overnight stay in the hospital. Depending on whether or not other intraocular surgeries are performed at the same time, the operation lasts between one half to two hours and involves removing the patient's hazy cornea and replacing it with a clear donor cornea that is sewn in place with nylon sutures. It is performed under an operating microscope and requires the patient to lie still. When the operation is complete, the patient is given topical medications and the eye should be patched overnight. Blood loss is minimal to none during the procedure.
Usual postoperative course
Expected postoperative hospital stay
Most patients go home on the day of surgery.
Operative mortality
Extremely low and generally associated with the anesthetic used.
103 - Vitreoretinal surgery
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- By G. Baker Hubbard III, Emory University, School of Medicine, Atlanta, GA, Enrique Garcia-Valenzuela, Emory University, School of Medicine, Atlanta, GA, Thomas M. Aaberg, Sr., Emory University, School of Medicine, Atlanta, GA
- Edited by Michael F. Lubin, Emory University, Atlanta, Robert B. Smith, Emory University, Atlanta, Thomas F. Dodson, Emory University, Atlanta, Nathan O. Spell, Emory University, Atlanta, H. Kenneth Walker, Emory University, Atlanta
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- Book:
- Medical Management of the Surgical Patient
- Published online:
- 12 January 2010
- Print publication:
- 10 August 2006, pp 702-703
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Summary
Vitreoretinal surgical techniques are used to address disorders of the posterior segment of the eye. Great strides have been made in the ability to safely and effectively operate in the posterior segment over the last 20 years. With the evolution of advanced microsurgical instruments, computerized infusion and aspiration systems, endolaser probes, perfluorocarbon heavy liquid for manipulation of detached retinal tissue, implantable slow-release pharmacological devices, wide angle optical viewing systems, and long-acting gases and silicone oil for intraocular tamponade, the spectrum of disorders which are amenable to operative intervention has broadened significantly. The treatment of intraocular tumors with radioactive episcleral plaques has also become well established in recent years. However, in many cases of primary retinal detachment, the most appropriate treatment remains the standard scleral buckling operation that has been performed for over 60 years.
The scleral buckling operation consists of placing a strip of silicone around the outside of the globe to cause a slight indentation or buckle of the eye wall. The buckle achieves its purpose because the indentation helps close the causative retinal tear inside the eye. A combination of support from the buckle and chorioretinal scarring induced by treating the tear with cryotherapy maintain closure of the retinal tear. Complex retinal detachments with very large or posteriorly located retinal tears, significant retinal scarring, vitreous hemorrhage, or severe cataract formation are usually approached with a combination of scleral buckle and the more advanced intraocular vitrectomy techniques listed above.
100 - General considerations in ophthalmic surgery
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- By Enrique Garcia-Valenzuela, Emory University, School of Medicine, Atlanta, GA, G. Baker Hubbard III, Emory University, School of Medicine, Atlanta, GA, Thomas M. Aaberg, Sr., Emory University, School of Medicine, Atlanta, GA
- Edited by Michael F. Lubin, Emory University, Atlanta, Robert B. Smith, Emory University, Atlanta, Thomas F. Dodson, Emory University, Atlanta, Nathan O. Spell, Emory University, Atlanta, H. Kenneth Walker, Emory University, Atlanta
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- Book:
- Medical Management of the Surgical Patient
- Published online:
- 12 January 2010
- Print publication:
- 10 August 2006, pp 693-697
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Summary
Numerous types of surgical intervention can be performed in the treatment of diseases of the eye and its adnexa. Owing to the great degree of technical skill required to execute these interventions, subspecialists perform a significant portion of ophthalmic surgeries. Microsurgery is involved in all procedures and most of the operations are limited to intervention into the eye and orbit with minimal risk to other organs. Ophthalmic surgery offers a high probability of success with a major positive impact on the quality of life. However, many patients with eye pathology are elderly and some have significant systemic illness, so the risk of elective intervention must be balanced against expected benefits. Optimal preoperative management of medical problems can make surgery safer and minimize patient discomfort.
Anesthesia
The large majority of ophthalmic interventions can be performed under local anesthesia with intravenous sedation. In some cases, even topical anesthetics are sufficient. Ophthalmic surgeries that require general anesthesia are those that involve significant extraocular manipulation in regions where a local anesthetic is not effective, and those that are prolonged as occurs in many vitreoretinal and orbital procedures as well as some cosmetic operations. General anesthesia is also indicated in younger patients and individuals who may not remain motionless during surgery and trauma cases with significant ocular laceration where administration of local anesthetics may raise intraorbital pressure with consequent extrusion of intraocular contents.
Several choices exist in the route of administration of local ophthalmic anesthesia for intraocular surgery.
104 - Glaucoma surgery
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- By Anastasios P. Costarides, Emory University, School of Medicine, Atlanta, GA, G. Baker Hubbard III, Emory University, School of Medicine, Atlanta, GA, Enrique Garcia-Valenzuela, Emory University, School of Medicine, Atlanta, GA, Thomas M. Aaberg, Sr., Emory University, School of Medicine, Atlanta, GA
- Edited by Michael F. Lubin, Emory University, Atlanta, Robert B. Smith, Emory University, Atlanta, Thomas F. Dodson, Emory University, Atlanta, Nathan O. Spell, Emory University, Atlanta, H. Kenneth Walker, Emory University, Atlanta
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- Book:
- Medical Management of the Surgical Patient
- Published online:
- 12 January 2010
- Print publication:
- 10 August 2006, pp 704-705
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Summary
Multiple ocular conditions can lead to the development of glaucoma, which is the most common optic neuropathy. All therapeutic interventions are directed towards lowering the condition's greatest risk factor, intraocular pressure.
Typically, therapy is instituted in an ascending fashion, with topical medical therapy being the first and simplest option. Medications include topical beta adrenergic blockers, prostaglandin analogs, carbonic anhydrase inhibitors, alpha adrenergic agonists, and miotics; these agents, used alone or in combination, are often sufficient for control of intraocular pressure. In cases of open angle glaucoma requiring greater management of intraocular pressure, laser trabeculoplasty, an outpatient procedure, is used in conjunction with medications. For angle closure glaucoma, outpatient laser iridotomy is applied to relieve the pupillary block mechanism.
Incisional intraocular surgery is the most frequent choice when medical and outpatient laser procedures fail to diminish intraocular pressure, with trabeculectomy and aqueous tube shunt placement being the most commonly used procedures. Both approaches lower intraocular pressure by allowing aqueous humor to leave the anterior chamber and collect in the subconjunctival space. When other interventions have either failed or are unfeasible, such cyclodestructive procedures as laser ablation or cryoablation of the ciliary processes may be done. Incisional surgery is done in an operating room, usually on an outpatient basis; cyclodestructive operations are performed in a clinic setting; and local anesthesia is standard for both methods.
Usual postoperative course
Expected postoperative hospital stay
Glaucoma surgery usually does not require hospitalization, though monocular patients undergoing incisional surgery may be hospitalized.
107 - Enucleation, evisceration and exenteration
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- By Enrique Garcia-Valenzuela, Emory University, School of Medicine, Atlanta, GA, G. Baker Hubbard III, Emory University, School of Medicine, Atlanta, GA, Thomas M. Aaberg, Sr., Emory University, School of Medicine, Atlanta, GA
- Edited by Michael F. Lubin, Emory University, Atlanta, Robert B. Smith, Emory University, Atlanta, Thomas F. Dodson, Emory University, Atlanta, Nathan O. Spell, Emory University, Atlanta, H. Kenneth Walker, Emory University, Atlanta
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- Book:
- Medical Management of the Surgical Patient
- Published online:
- 12 January 2010
- Print publication:
- 10 August 2006, pp 710-712
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Summary
Ophthalmic surgeons may want to remove ocular structures when they are affected by neoplasia, when they are distressed by a severe infectious process, or when an end-stage ocular disease is causing pain. There are three types of ophthalmic intervention:
Enucleation
Removal of the entire eyeball, including sclera and cornea, leaving a stump of the optic nerve and the extraocular muscles. An intraorbital prosthesis is usually implanted.
Evisceration
Removal of all intraocular structures, leaving only sclera and sometimes cornea. An ocular prosthesis is usually implanted.
Exenteration
Removal of the eyeball and the orbital contents which may include removal of orbital bone.
Enucleation is the most frequently performed surgical approach for elimination of intraocular structures. When ocular disease has rendered an eye completely blind (incapable of perceiving the brightest light), any possibility of visual recovery is minimal. Frequently, such severity of pathology makes an eye painful and cosmetically unacceptable in spite of medical treatment. Although there are several procedural choices, the most widely accepted surgery is removal of the eye or enucleation because of its long-term outcome and safety. A frequent scenario where enucleation is recommended is after severe ocular trauma. A blind eye should be enucleated within 2 weeks after trauma to prevent sympathetic ophthalmia, a rare complication where the exposed uveal tissue leads to autoimmune attack of the contralateral healthy eye. Other indications for enucleation include infectious endophthalmitis, end-stage glaucoma, and malignant intraocular tumors.
105 - Refractive surgery
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- By C. Diane Song, Emory University, School of Medicine, Atlanta, GA, Enrique Garcia-Valenzuela, Emory University, School of Medicine, Atlanta, GA, G. Baker Hubbard III, Emory University, School of Medicine, Atlanta, GA, Thomas M. Aaberg, Sr., Emory University, School of Medicine, Atlanta, GA
- Edited by Michael F. Lubin, Emory University, Atlanta, Robert B. Smith, Emory University, Atlanta, Thomas F. Dodson, Emory University, Atlanta, Nathan O. Spell, Emory University, Atlanta, H. Kenneth Walker, Emory University, Atlanta
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- Book:
- Medical Management of the Surgical Patient
- Published online:
- 12 January 2010
- Print publication:
- 10 August 2006, pp 706-707
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Summary
Done to reduce dependence on glasses or contact lenses, refractive surgery involves reshaping the cornea with incisions, heat, or laser to decrease myopia, astigmatism, or hyperopia. Presently, the most frequently performed refractive surgical procedure is laser-assisted in situ keratomileusis (LASIK).
LASIK can correct refractive error within a wide range. To deduce whether LASIK is a good option for a patient, a thorough preoperative eye exam is necessary. Indications may include intolerance to contact lenses, improved conditions for job-related or hobby-related activities, or a desire to lessen reliance on glasses and contact lenses.
Performed in an outpatient setting with topical anesthesia, the operation usually lasts about 15 minutes with the patient experiencing minimal discomfort. Both eyes may be operated on the same day. After it is cut, the thin corneal flap is lifted and reflected to allow the laser to reshape the cornea. The laser is programmed with the patient's refractive error; once that refractive error is corrected, the corneal flap is realigned into place.
Usual postoperative course
Expected postoperative hospital stay
Most surgeries are performed in a surgicenter on an outpatient basis.
Special monitoring required
The patient's eyes are generally not patched, though sunglasses may be necessary if there is sensitivity to light. Discomfort is minimal postoperatively.
Patient activity and positioning
Most patients will be able to see well enough on the first postoperative day to return to regular activity, though they require reading glasses for near vision if they are in the presbyopic age range.
101 - Cataract surgery
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- By G. Baker Hubbard III, Emory University, School of Medicine, Atlanta, GA, Enrique Garcia-Valenzuela, Emory University, School of Medicine, Atlanta, GA, Thomas M. Aaberg, Sr., Emory University, School of Medicine, Atlanta, GA
- Edited by Michael F. Lubin, Emory University, Atlanta, Robert B. Smith, Emory University, Atlanta, Thomas F. Dodson, Emory University, Atlanta, Nathan O. Spell, Emory University, Atlanta, H. Kenneth Walker, Emory University, Atlanta
-
- Book:
- Medical Management of the Surgical Patient
- Published online:
- 12 January 2010
- Print publication:
- 10 August 2006, pp 698-699
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Summary
Cataracts are characterized by opacity of the crystalline lens of the eye and are the primary cause of preventable blindness in the world. They may be congenital or age related; secondary to exposure to drugs, toxins, or radiation; or the product of various metabolic diseases. Visually significant cataracts are a major public health issue and are found in 50% of persons 65 to 74 years of age and 70% of persons 75 years of age or older.
Modern cataract extraction with placement of an intraocular lens (IOL) is a highly effective and efficient operation to restore visual acuity and contrast sensitivity in patients with severe cataracts. Presently, the operation has evolved to the point where it involves constructing a small (2.5–3.5 mm) wound at the edge of the cornea. The incision is carefully shelved to minimize leakage through the wound, viscoelastic material is injected into the anterior chamber to protect the cornea, and the anterior capsule of the lens is removed. An ultrasound probe (phacoemulsification tip) is then inserted into the anterior chamber and used to fragment and remove the cataractous lens, though the capsule of the lens is left intact except for a small opening in the anterior portion through which the phaco tip had been inserted. An IOL with appropriate focusing power to neutralize any refractive error is chosen based on the size and corneal curvature of the patient's eye.