Orbital decompression

From EyeWiki


Introduction

This article reviews the indications, preoperative evaluation, surgical management and postoperative care for orbital decompression patients.

Indications for orbital decompression

The main indication for orbital decompression is proptosis (bulgy eyes). The etiologies of the proptosis include thyroid eye disease (Graves disease), congenital shallow orbits, relative maxilla hypoplasia, orbital tumors, and orbital hemorrhage, although orbital decompression is rarely done for the latter two etiologies. Orbital decompression is done to reduce the bulgy appearance of the eyes, either for functional (medical) or cosmetic reasons (cosmetic orbital decompression), by removing orbital fat and bone.

Another rare indication for orbital decompression is compressive optic neuropathy.

Anatomy of eye/orbit

A thorough understanding of the eye/orbit is essential when evaluating patients for possible orbital decompression. The orbit is a solid structure that houses the eyeball, fat, muscles, vessels, and nerves. The orbit itself is surrounded by the maxillary sinus inferiorly, ethmoid sinus medially, brain superiorly, and temporalis muscle temporally. Orbital decompression involves removing or thinning various safe orbital walls (and orbital fat), thereby expanding the eye socket, allowing the eyeball to settle back. It can be customized according to the need of proptosis reduction along with functional and cosmetic needs.

Diagnosis

Clinical examination of the eye, orbit, and surrounding structures is critical to determine the etiology of the proptosis, severity of the proptosis, and other contributing factors. Orbital/head imaging (CT and/or MRI) would assist in determination of the cause of the proptosis and help assist in planning for the customized surgery by visualizing the position/thickness of various orbital bones and surrounding structures.

Physical examination

Eye/eyelid/orbit examination, including:

  • Full eye exam (vision, ocular motility, pupil, intraocular pressure, anterior segment exam, dilated fundus exam)
  • Eyelid examination (eyelid position, function, lagophthalmos, etc)
  • Orbital exam (bony structure, presence of any masses, retropulsion, Hertels measurements)
  • Asymmetry
  • Periocular exam (edema, erythema, etc)

Signs

The degree of proptosis varies from subtle to very severe, with symptoms ranging from none to various symptoms (see below).

Symptoms

Proptosis can be subtle without any symptoms or severe with various symptoms including inability to close the eyes with dry eyes, tearing, redness, pain, diplopia (double vision), asymmetry, etc.

Clinical diagnosis

Physical examination is critical in diagnosing proptosis and its severity. Looking at old patient's eye/face photos can be useful as well.

Diagnostic tests/procedures

The main diagnostic tool is orbital/head imaging (CT or MRI), although certain blood tests may add value depending on the etiology of the proptosis.

Differential diagnosis

Eyelid retraction and globe malposition can give illusion of bulgy eyes.

Management

Medical therapy

Lubrication (and other dry eye therapy) is useful for treating some of the symptoms of proptosis, depending on its severity. Other medications may be needed, depending on the etiology of the proptosis. Proptosis itself is treated surgically (via orbital decompression).

Surgical steps

Orbital decompression is performed under general anesthesia. Orbital decompression is performed for either functional or cosmetic reasons. More orbital decompression (greater amount of bony and fat removal or debulking) is usually necessary for functional (medically necessary) orbital decompression and usually less is needed for cosmetic orbital decompression. The surgical principle is the same in both, where various amounts of orbital fat and orbital bone is removed. The best and safest first orbital wall to remove (or thin out) is the lateral orbital wall, followed by the medial wall, and last the orbital floor. More reduction with added risk is taken as more walls are decompressed. Incisions are hidden in the lateral upper eyelid crease (for lateral orbital decompression), caruncle or transcaruncular (for medial wall decompression) and lower eyelid conjunctiva (for orbital floor decompression).

Postoperative regimen

Orbital decompression is done on outpatient basis, usually one eye at a time although both eyes can be done together. Since there are no eye patches placed, the patient is immediately able to see after surgery. There is some pain in the first day of the surgery, controlled by oral pain medication. There is fair amount of bruising/swelling around the eye which lasts up to 2 weeks. The patient is asked to limit physical activity for 10 days and not blow their nose. Follow up is one week, one month, and three months after surgery.

Complications

  • Double vision
  • Asymmetry
  • Under correction
  • Over correction
  • Bleeding
  • Infection
  • Other rare complications

Prognosis

The effect of orbital decompression is noticed soon after surgery with high success rate.

Additional resources

ASOPRS Information for Patients on orbital decompression.