Enucleation is a definitive surgery for intraocular tumors, globe perforations where the eye cannot be salvaged, blind painful eyes, and disfigured eyes. The surgery, if performed with implant placement in experienced hands, can give excellent results in terms of eliminating the pathology and achieving good cosmesis.
The objectives of this surgery are to remove the eye (keeping the integrity of the sclera and ocular structures intact) and to achieve the best cosmetic outcomes in an anophthalmic socket by minimizing socket deformities.
Completely remove the globe for treatment of tumor, infection, or pain.
The orbital implant should be of adequate volume and lie in the most natural position in the orbit.
The orbital implant should have excellent motility in order to transmit the movement to the prosthesis.
The integrity of the anophthalmic socket is responsible for holding the ocular prosthesis in the sulci for prolonged periods of time. Gravitational forces may displace the prosthesis, so sulcus adequacy is of prime importance.
The eyelids should have adequate opening and closure with the prosthesis in place.
An ocular prosthesis in place should look as close to the normal eye as possible.
Provides dramatic relief to the patient with a painful blind eye commonly due to absolute glaucoma, endophthalmitis, or penetrating trauma. Improved cosmesis with a prosthesis can also provide psychological comfort.
Although risks are small, minimizes the risks of sympathetic ophthalmia seen in traumatic globes with uveal prolapse.
Permits a complete histological examination of the eye and optic nerve influencing future treatments particularly in intraocular tumor cases.
Advanced prosthesis designs allow the surgeon to compensate for the loss of volume after globe removal and custom-made prostheses give excellent cosmetic results which match the contralateral eye.
Alleviation of pain in the enucleated side (if present).
Removal of tumor or lesion for histological diagnosis to determine further management.
Aesthetically acceptable anophthalmic socket with a mobile ocular prosthesis.
40.4 Key Principles
Clinical evaluation including history, imaging, and detailed consent.
Careful identification and marking of the eye to be enucleated is crucial on the day of the surgery.
Adequate preservation of the conjunctiva, Tenon capsule, and extraocular muscles during surgery.
Choosing the right implant with the best fit for the anophthalmic socket.
Preservation of fornices on closure to maintain the prosthesis adequately.
Address any volume deficits like fractures or contracted socket to consider simultaneous volume enhancement to match the contralateral eye.
Working with an ocularist to make a customized prosthesis for the most natural look.
Trauma to the globe where globe salvage is not possible. Above tumors, trauma is the most common reason for enucleation in the United States. The surgery can rarely be a primary enucleation if globe repair is not possible. Secondary enucleation can be performed if there is infection or pain. Surgery in the setting of sympathetic ophthalmia has only been demonstrated to be beneficial to remove the inciting eye within 14 days of the onset of sympathetic ophthalmic symptoms/findings. In a comprehensive review of 24,444 enucleation specimens obtained over 55 years, Spraul and Grossniklaus found that trauma had been the cause of enucleation in 40.9% of cases and neoplastic disease had been the cause in 24.2%. 3 , 4
Blind painful eye secondary to absolute glaucoma, neovascular glaucoma, failure of filtration procedures, endophthalmitis and panophthalmitis, corneal ulceration, and perforation. 5
Severely disfigured, phthisical eyes without useful vision which may be psychologically distressing to the patient. In these patients, it is critical they understand that surgery may improve the current deformity but may not match the other eye completely. The patient should be counseled about postoperative ptosis, superior sulcus deformity, and enophthalmos. 6
A seeing eye. The importance of a thorough clinical exam, fundus exam, imaging, and visual evoked potentials cannot be understated. Any patient with visual potential should be considered carefully (e.g., intractable pain in an eye with light perception vision).
Intraocular tumor with extrascleral or orbital involvement and/or metastatic disease (e.g., retinoblastoma with extraocular seeding or choroidal melanoma with extension outside of the globe). These cases may require additional nonsurgical treatment or possible exenteration.
Extraocular primary tumor with intraocular metastatic disease. It is important to rule out the possibility of a primary neoplasm or metastatic disease elsewhere. 7
40.7 Preoperative Preparation
Preoperative evaluation consists of obtaining informed consent and a medical evaluation. Patients must be offered alternative treatments and counseled as to a realistic surgical and cosmetic outcome. This is one of the most important preoperative considerations in surgery for enucleation.
Taking a thorough history gives the surgeon insight on what may be encountered during surgery. History of scleral buckle surgery, filtering procedures for glaucoma, drug reactions, and conjunctival scarring should be identified prior to surgery. Implants used in the aforementioned surgeries can cause scarring of conjunctiva and Tenon capsule, further shortening of the fornices, as well as postoperative inflammatory reactions. History of anticoagulants and oculofacial trauma is also important. 7
40.7.1 Clinical Evaluation
The value of a detailed eye examination cannot be understated.
Vision assessment including light perception and projection of light in a dark room. In the event of doubt, a visual evoked potential maybe considered.
Examination of the conjunctival fornices and the ocular surface in order to prepare for possible foreshortening with closure and scarring.
Pupillary reaction, slit-lamp anterior segment evaluation, and integrity of the limbus since areas of scleral thinning may rupture and cause expulsion of ocular contents during nerve resection.
If there is no view to the posterior to the pupil, a B-scan ultrasound is indicated to rule out intraocular tumors, retroorbital masses, and thickened extraocular muscles. The B-scan also allows a rough estimate of the axial length from which the size of the implant can be calculated. In patients with a history of trauma, a CT scan may be ordered to evaluate the orbital walls and the sinuses. 7
Evaluation of the periorbita and the orbit. Volume assessment in relation to the contralateral eye.
Complete systemic evaluation. Patients with intraocular tumors should be evaluated for metastatic disease before surgery.
In the operating room, it is important for the surgeon to review the patient’s record and examine the patient’s eye to ensure that the correct eye is enucleated. Eye should be marked prominently and confirmed with the patient prior to anesthesia and placement of a shield over the nonoperative eye to avoid accidental injury during surgery.
40.8 Operative Technique
40.8.1 Anesthesia Options
Monitored anesthesia care (MAC), anesthesia (retrobulbar anesthesia with conscious sedation), or general anesthesia may be used. Most physicians prefer general anesthesia as the patient may become uncomfortable despite adequate blocking techniques.
Instruments are 0.5 forceps and/or Bishop-Harmon forceps, muscle hook, Castroviejo needle driver, bipolar cautery, Kelly or 90-degree clamp, bulldog/serrefine clips, Westcott and Stevens tenotomy scissors, Metzenbaum or enucleation scissors, Wells enucleation spoon, sponges and cotton-tipped applicators, thrombin, local anesthetic, or cocaine (can soak sponges and apply for local hemostasis), malleable retractor, implant and suture materials: 5–0 or 6–0 polyglactin, 4–0 silk. 7
40.9 Surgical Technique
An eyelid adjustable wire speculum is placed, and a 360-degree conjunctival limbal peritomy using Westcott scissors is performed. Care is taken to keep the curve of Westcott following the curvature of the limbus to allow smooth separation of the conjunctiva and maximal preservation of the conjunctiva (Fig. 40‑1). Keeping the Tenon capsule intact during dissection is of utmost importance. Once the peritomy is done, Stevens tenotomy scissors are used to bluntly dissect in each oblique quadrant. A good technique is to lift the conjunctiva and then gradually separate the blades of the tenotomy scissors to make an adequate pocket. The dissection can be carried out deep just beyond the globe (Fig. 40‑2).
Each of the rectus muscles is localized with the aid of a muscle hook (Fig. 40‑3). Minimal cleaning of the tissue at the muscle insertion is carried out so that Tenon fascia is disturbed as little as possible in this area. A good way is to use moistened cotton-tipped applicators to bare the tendon and muscle. Once the rectus muscle is identified, the muscle can be tented off the globe with the help of an assistant and two muscle hooks. This allows a free path to pass the double armed 6–0 polyglactin suture in a whiplock fashion to secure the muscle tendon. This maneuver is important as globe perforation with a needle, especially in intraocular tumors, can cause orbital seeding. Once the suture is secure, the muscle is released from the globe. The suture is then placed in a serrefine clamp. 8
The oblique muscles are also identified and released from the globe. Sometimes, the oblique muscles can be hard to identify by a beginner. It is best to sweep the muscle hook lateral to medial to hook the inferior oblique muscle. The trochlea and the origin of inferior oblique are easy to find along the medial orbital rim. Some surgeons tag the inferior oblique muscle with a polyglactin suture in similar fashion as is performed with the rectus muscles. It is then used as a hammock to prevent implant migration. The superior oblique is severed and allowed to retract. 8
Although the optic nerve can be accessed medially or laterally, the author prefers a lateral approach. A 4–0 silk suture can be attached to the lateral rectus insertion site to allow traction of the globe anteriorly. Others directly grasp the lateral rectus stump itself. Once all the muscles have been isolated, the eyelid speculum is removed. A Wells enucleation spoon is introduced into the field. It slides behind the globe and hugs the optic nerve at its insertion. The spoon is rotated to free any residual Tenon attachments. The globe is gently retracted anteriorly by lifting the spoon. At this point, the lateral rectus is pulled laterally and the curved Metzenbaum scissors introduced. The optic nerve is localized on either side of the intraorbital optic nerve. The nerve is gently strummed with the closed blades of the scissor. Once the depth of nerve to be incised is identified, the lateral rectus is pulled, and the nerve is severed. Pressure is applied to the socket with thrombin- or cocaine-soaked sponges (or simply saline) for 5 minutes to achieve hemostasis. Malleable retractors are then used to gently retract orbital fat away from the optic nerve stump. Actively bleeding vessels are then cauterized under direct visualization (Fig. 40‑4). 8
After hemostasis has been achieved, the implant is prepared. Some surgeons prefer wrapping the implant in donor sclera, while others suture the recti directly onto the implant (Fig. 40‑5). Proper selection of implant volume helps minimize superior sulcus deformity and enophthalmos. Implant size can be used to approximate the capacity of the orbit while taking into account the amount of conjunctiva available. The exact location for implant placement varies among ophthalmic surgeons. Some surgeons prefer to have the orbital implant remain partly within Tenon space and partly behind Tenon (in the intraconal space). Other surgeons prefer placing the implant entirely within the intraconal space. An implant introducer (e.g., Carter sphere introducer; Storz, Bausch & Lomb, Inc., New Jersey) facilitates implant placement while the edges of Tenon fascia are retracted with double-pronged skin hooks (Fig. 40‑6). It is important to avoid dragging anterior Tenon fascia deep with implant placement (a common problem with porous orbital implants). Once the implant is placed into the orbit, surgeons routinely “seat” the implant. To do this, gentle pressure is applied to the anterior implant surface using a cotton-tipped applicator while an Adson toothed forceps is used to unravel any rolled Tenon edge. Additional pressure is applied to the implant with a cotton-tipped applicator while pulling anteriorly on Tenon to place the implant deeper. 8
The sutures from the rectus muscles are secured to the anterior portion of the wrapped implant just anterior to their normal anatomic insertion sites. Surgeons generally attach the rectus muscles to the implant so that they are approximately 8 to 10 mm away from the antagonist rectus muscle (Fig. 40‑7). 8
Anterior Tenon fascia is closed meticulously with a buried 6–0 polyglactin suture in an interrupted fashion. It is extremely important that Tenon not be closed under tension. Conjunctiva is then closed in meticulous fashion taking care not to bury conjunctiva within the wound with a running suture (6–0 polyglactin suture). Closing the anterior Tenon fascia and the conjunctiva is best done with the speculum under minimum tension. This minimizes button-holing while closing the anterior tissues. At the end, the speculum is removed, a large rigid conformer is placed, and a temporary tarsorrhaphy is performed (Fig. 40‑8).