- 1.
What complications may result from local anesthesia for cataract surgery?
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Retrobulbar hemorrhage is the most common complication from retrobulbar injection. Blood collects in the retrobulbar space, often causing proptosis of the involved eye and a tense orbit. If not treated, it may lead to severe, irreversible optic nerve ischemia.
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Ocular perforation may occur if the needle perforates the globe. The risk of this complication is greatest in highly myopic eyes with long axial lengths.
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Optic nerve sheath hemorrhage may occur if the needle penetrates the optic nerve. It may result in a secondary central retinal vein and/or central retinal artery occlusion.
Peribulbar injections given with a shorter needle have become more popular recently, as has topical anesthesia for cataract surgery.
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- 2.
How do you treat a retrobulbar hemorrhage?
Blood collecting in the retrobulbar space may cause a secondary increase in intraocular pressure from the pressure of the blood on the globe. When a retrobulbar hemorrhage occurs, intermittent pressure is applied initially to the globe to tamponade the bleeding. The intraocular pressure should be measured. If it is significantly elevated, a lateral canthotomy should be performed. This technique is often successful in relieving the pressure on the globe. Surgery is usually canceled when a retrobulbar hemorrhage occurs.
- 1.
Posterior capsule rupture
- 2.
Dislocated lens fragment
- 3.
Iris trauma
- 4.
Thermal corneal injury
- 5.
Descemet tear/detachment
- 6.
Poor intraocular lens placement
- 7.
Choroidal/expulsive hemorrhage
- 3.
What are the common complications related to the cataract wound?
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Wound leak or dehiscence: Occurs when apposition of the cataract wound is inadequate. Aqueous humor can be seen leaking from the involved area of the wound.
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Wound burn: Transfer of heat from the vibrating needle of the phacoemulsification instrument can induce an incision burn adversely affecting wound apposition.
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Hypotony: If a wound leak is present, the intraocular pressure is usually low.
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Flat anterior chamber: If the wound leak is large enough, the anterior chamber becomes shallow and may become flat with the iris contacting the cornea.
Most wound leaks require repair in the operating room with additional sutures to achieve a watertight closure.
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- 4.
What is iris prolapse? How is it treated?
If a wound leak is present, the iris often becomes incarcerated in the wound and may prolapse, leading to increased inflammation and increased risk of infection. Prolapse requires repair in an operating room. If the iris is viable, it can be reposited in the eye; if not, it can be excised. Additional sutures are necessary in the area of the wound dehiscence.
- 5.
What types of intraocular hemorrhage may occur during or after cataract surgery?
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Hyphema or blood in the anterior chamber can be seen as a layering or meniscus of blood in the anterior chamber. Blood vessels in the base of the cataract wound or possibly from the iris are usually the source of the blood. Most often the blood clears spontaneously, and no treatment is required. The intraocular pressure needs to be monitored closely because secondary elevation may occur.
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Expulsive choroidal hemorrhage is the most feared complication of cataract surgery and is caused by rupture of choroidal vessels, most often during surgery. The rupture causes a rapid rise in intraocular pressure with loss of the anterior chamber, iris prolapse, and possible prolapse of the entire intraocular contents if not recognized and treated promptly. Fortunately, it has an occurrence rate of 0.2%.
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- 6.
What is the incidence of posterior capsule rupture for an experienced surgeon during cataract surgery?
Most studies report between 1% and 3%.
- 7.
What are the possible consequences of posterior capsule rupture?
Posterior capsule rupture is often associated with vitreous loss. It may result in loss of lens material into the vitreous cavity ( Fig. 23-1 ). It also increases the risk of endophthalmitis and retinal detachment.
Figure 23-1
Posterior capsule rupture may lead to loss of nuclear fragments into the vitreous. In this case nearly the entire lens “dropped” following a circumferential extension of a radial tear during capsulorrhexis.
- 8.
What are some of the risk factors for expulsive choroidal hemorrhage? How are they treated?
Patients with advanced age, systemic hypertension, arteriosclerosis, glaucoma, and long axial-length eyes are at greater risk. Time is of the essence in responding to this operating room emergency. The wound must be closed as quickly as possible; in fact, the surgeon may tamponade the wound with his or her thumb until a suture is ready. Sutures should be rapidly placed and the patient’s eye closed. Some surgeons advocate performing posterior sclerotomies to release accumulated blood. The prognosis for visual outcome is usually quite poor.
- 1.
Corneal edema
- 2.
Cystoid macular edema
- 3.
Inflammation/uveitis
- 4.
Wrong intraocular lens power
- 5.
Secondary membrane
- 6.
Glaucoma/elevated intraocular pressure
- 7.
Wound leak
- 8.
Retinal detachment
- 9.
Diplopia
- 10.
Ischemic optic neuropathy
- 9.
What are the causes of postoperative inflammation?
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Operative trauma. All eyes show some postoperative uveitis, characterized by cell and flare reaction in the anterior chamber. Despite individual variation, the degree of inflammation is usually proportionate to the degree of trauma induced by the surgical procedure. Procedures with longer surgical times and/or additional procedures (i.e., vitrectomy or iris manipulation) show greater amounts of inflammation.
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Retained lens material. Fragments of lens material—either nucleus or cortical remnants—may cause inflammation. In almost all cases cortical remnants resorb and require no additional treatment. Nuclear fragments may become a source of chronic inflammation that leads to macular edema. Most nuclear remnants require surgical removal.
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Foreign body reaction to intraocular implants may occur. This is more common when implants are poorly positioned, especially when they are in contact with uveal tissue. Some patients, particularly those with a history of uveitis, may react to the intraocular lens (IOL) material.
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- 10.
How does infectious endophthalmitis present? When does it usually occur?
The classic presentation includes severe ocular pain, decreased vision, eyelid swelling, conjunctival chemosis, and hypopyon. Corneal edema and diminution or loss of the red reflex often occurs. This condition must be suspected in any patient who presents with more inflammation than expected postoperatively. On average, patients developed signs and symptoms 6 days after surgery. More than three-fourths of patients developed signs and symptoms within 2 weeks ( Fig. 23-2 ).
