I. INTRODUCTION

The ophthalmic surgical patient can undergo either intraocular or extraocular surgery. Depending on the type of surgery that has been performed, different complications can result. In addition, different modes of anesthesia, including topical, regional, or general anesthesia, can be used. Topical and regional blocks have unique complications that are important to be aware of when managing the postoperative ophthalmic patient. The most common ophthalmic procedures and their operative and associated anesthetic complications will be discussed in the sections below.

II. OPHTHALMIC SURGERY

Ophthalmic procedures can generally be divided into intraocular and extraocular surgery. Intraocular procedures can include surgeries for cataract, corneal diseases, glaucoma, retinal repairs, and ruptured globe repairs. Extraocular procedures include strabismus and oculoplastic surgeries. Ophthalmic procedures are typically performed on an outpatient basis, and the patient is often discharged home from the postanesthesia care unit the same day. Depending on the type of procedure, different types of anesthesia may be required. General anesthesia is mandatory in cases of ocular perforation and intraorbital procedures.

A. Intraocular Surgery May Result in Pain and Discomfort if an Abrasion Exists

1. Cataract surgery

a. Cataract surgery is performed when the natural intraocular lens becomes cloudy. In most uncomplicated cases, it is performed using only topical and intracameral (within the anterior chamber) anesthesia. The surgeon makes two small incisions through the cornea and uses phacoemulsification (powerful ultrasound) to remove the lens and place a synthetic lens in the eye. Wound closure often does not require a suture, but with complicated cases or with larger incisions, a small suture may be necessary. Patients are discharged from the hospital the same day with postoperative follow-up the following morning.

b. Most complications of cataract surgery occur during the procedure itself (e.g., rupture of the posterior capsule occurs in approximately 1.9% of cases) and managed acutely by the surgeon.

c. Early postoperative complications include:

1. Corneal edema presenting as a decrease in vision and may result in pain and discomfort if an abrasion exists.

2. Intraocular pressure spikes resulting in pain and nausea. This is uncommon, but can be seen if the viscoelastic substance used intraoperatively is not completely removed at the time of surgery. Additionally, low intraocular pressure can occur secondarily to a leaking wound, resulting in visual disturbances, often without pain.

3. Uveitis (inflammation) typically presents with blurred vision, conjunctival erythema, discomfort and photophobia.

4. Endophthalmitis is an intraocular bacterial or fungal infection and is a severe and sight-threatening major postoperative complication. Fortunately, it occurs rarely in approximately 0.05% to 0.33% of cases, and usually presents 3 to 7 days after surgery. This is an absolute emergency and needs to be addressed urgently.

2. Corneal surgery

a. Corneal surgeries include corneal transplants and refractive surgery. Performing a penetrating keratoplasty (corneal transplant) implies that the eye will be open to the air for a few minutes during the surgery, with risk of expulsion of the intraocular contents. Retrobulbar blocks are mandatory and sedation is often necessary. During an endothelial keratoplasty, only the deeper part of the cornea is replaced.

b. Postoperative complications include:

1. Weak sutures with or without leakage of aqueous humor resulting in hypotonia.

2. Suture infections and endophthalmitis resulting in pain, photophobia, and visual impairment.

3. Corneal erosions, graft rejection, and uveitis presenting with pain, photophobia, and decreased vision.

3. Glaucoma

a. Glaucoma surgery is performed to decrease uncontrolled intraocular pressure that fails to respond to medical management. There are generally two types of glaucoma: open-angle glaucoma and closed-angle glaucoma. “Open angle” means that the angle where the iris meets the cornea is as wide and open as it should be. Glaucoma can result when the trabecular meshwork (the eye’s drainage system) has become blocked, thereby increasing the intraocular pressure in the eye. When the angle is closed, it is the narrowness of the angle that blocks the trabecular meshwork from draining the aqueous humor, thereby increasing the intraocular pressure.

In general, the purpose of glaucoma filtering surgery is to create a new drainage canal that allows external filtration of aqueous into the subconjunctival space. The aqueous can be drained via the conjunctiva (bleb) or through a device (tube shunt) and may be reabsorbed through the ophthalmic veins.

b. Postoperatively, patients can experience temporary mild to moderate ocular discomfort and are discharged home the same day.

c. Major early postoperative complications (i.e., those occurring in less than 3 months) include low intraocular pressure (from leakage of the conjunctiva, from excessive filtration, or associated with choroidal effusion), high intraocular pressure (from malignant glaucoma, pupillary block, or subchoroidal hemorrhages), infection (blebitis/endophthalmitis), hyphema (blood in the anterior chamber), or uveitis (inflammation in the eye).

4. Trauma

a. Globe perforations need to be repaired under general anesthesia and the patient is typically admitted overnight. The mechanism of trauma itself as well as duration of the surgical repair may increase the risk of infection. Pre- and postoperative antibiotics are usually provided, as well as intravitreal injection of antibiotics, if there is a possibility that the vitreous may have been contaminated.

b. Postoperative complications include those associated with intraocular surgery, such as corneal erosion, exposed or infected sutures, wound leakage with or without hypotony, elevated
intraocular pressure, and infections (endophthalmitis). Postseptal cellulitis is a rare complication.

5. Retina

a. Retinal detachment, macular holes, complicated cataract surgeries with rupture of the posterior capsule and trauma are examples of indications for posterior segment surgeries. Retrobulbar anesthesia is performed in these cases to ensure complete akinesia of the eye, with analgesia of the intra- and extraocular contents. Patients are typically discharged the same day.

b. The two main types of ocular surgery for retinal detachment repair are scleral buckle and vitrectomy.

1. A scleral buckle is a piece of silicone, rubber, or semihard plastic placed on the sclera. The material is sewn to the eye to relieve vitreal traction on the retina. This allows the retinal tear to settle against the wall of the eye. Retrobulbar anesthesia usually precludes the development of the oculocardiac reflex (OCR) when the muscles are stretched or pulled. Patients may experience moderate pain postoperatively and may require pain medicine in most cases. Postoperative complications include double vision (usually resolving without treatment), infection (postseptal cellulitis), or failed retinal apposition.

2. Pars plana vitrectomy is an intraocular surgery that involves removal of vitreous from the eye using three surgical ports through the sclera. In many cases, gas will be injected into the eye at the end of the procedure. Patients need to keep a specific head down position in order to keep the gas within the eye in the proper position. Postoperative complications include increased intraocular pressure, low intraocular pressure, infection (endophthalmitis), failure to reattach the retina, and inflammation (uveitis).

B. Extraocular Surgery

1. Strabismus

a. Strabismus surgery is used to correct misaligned eyes. Most surgeons operate under general anesthesia for the patient’s comfort. The muscles, in one or both eyes, are detached from the globe, then either resected (strengthened) or recessed (weakened) to enable both eyes to orient in the same direction and maximize motility. It is a fairly well-tolerated surgery, and patients are discharged home the same day.

b. One frequent intraoperative complication encountered by the surgeon and anesthesiologist is bradycardia associated with pulling or stretching of the extraocular muscles. Use of adjustable sutures has become a popular method of strabismus correction, and patients may experience significant vasovagal responses during the adjustment period, but this is not an issue once the patient is discharged home.

c. Postoperatively, complications can include slippage of the reattached extraocular muscle. This often results in significant diplopia and limitation of eye movement, in the direction of action of the slipped extraocular muscle. This is often the result of a broken suture and the patient should be evaluated by his or her strabismus surgeon immediately. Infections such as intraorbital cellulitis or the development of abscesses are rare complications and tend to occur later in the postoperative course. A conjunctival granuloma can be seen as part of the chronic healing process as a result of a local reaction to the suture material and usually responds to topical corticosteroid drops.

2. Oculoplastic surgery

a. Eyelid procedures are typically performed under local anesthesia, whereas orbital procedures are performed under general and peribulbar anesthesia. Peribulbar anesthesia is also used to decrease bleeding by vasoconstriction. The development of a retrobulbar hematoma leading to visual impairment (by causing a compressive optic neuropathy) is a rare, but serious complication that can be associated with elective blepharoplasty and presents in the early postoperative period with proptosis, chemosis, and decreased vision. This is an ophthalmic emergency requiring urgent recognition and treatment with canthotomy and cantholysis. (I feel urgent CT would actually be a mistake here and fail to decompress the optic nerve STAT to restore vision).

b. Other major complications include infections, such as preseptal or postseptal cellulitis, or the development of abscesses.