If vision loss is rapid and progressive, surgical orbital decompression may be required to relieve pressure on the optic nerve and its blood supply – typically after a failed trial of corticosteroids.
This invasive procedure involves removal of bone and sometimes adipose tissue to provide access to space outside the orbit, which allows excess tissue to decompress from the confined orbit.
Lateral wall decompression
Partial- or full-thickness inner aspects of the zygomatic bone and greater wing of the sphenoid bone are removed, which is typically performed through a canthotomy with inferior cantholysis.
Potential complications include cerebrospinal fluid leak secondary to dural tear, pulsatile exophthalmos, and oscillopsia .
Medial wall decompression
Segments of the ethmoid bone are removed allowing intraorbital contents to expand into the ethmoid air cells.
The lateral wall of the sphenoid bone may be removed as well.
The approach may be external or endoscopic.
When an external incision is made, it is typically transcaruncular and/or an extension of the orbital floor decompression incision, when applicable.
Diplopia secondary to alteration of globe position may occur.
Medial rectus prolapse into the ethmoid sinus can cause an abduction deficit.
Compression of the lesser wing of the sphenoid can cause internal carotid artery laceration or optic nerve damage.
Orbital floor decompression
This allows for expansion of orbital contents into the maxillary sinus.
Decompression may be performed just medial to the infraorbital nerve (largest area with the most benefit in decompressing the optic nerve) or may be both medial and lateral to the infraorbital nerve.
The optic strut is often left intact to minimize globe displacement.
Caution must be taken to avoid the infraorbital neurovascular bundle, which traverses the infraorbital canal.
Decompression is typically performed through a transconjunctival incision with a lateral canthotomy and inferior cantholysis, but a subciliary approach is used as well.
Potential complications include diplopia secondary to globe ptosis, supraduction deficit from inferior rectus prolapse, and CN V2 - distribution hypoesthesia.
Orbital fat decompression
The orbital fat may be removed alone or in conjunction with bony decomposition.
Orbital fat decompression has been shown to be especially beneficial in patients who tend to have more orbital fat hypertrophy than EOM involvement, which is more common in patients < 40 years old.
Pre-operative planning with computed tomography (CT) 
This may help confirm the diagnosis of TED.
CT allows for evaluation of the anatomy of the sinuses, cribiform plate, and lateral wall of the orbit.
CT also helps assess the potential benefit of fat and bone removal.
Considerations with orbital decompression surgery
Decompression may be of any wall alone or in combination with other walls.
The medial wall and orbital floor decompressions are of the most benefit in compressive optic neuropathy but have a slightly higher rate of diplopia post-operatively.
The decompression is called "balanced" when the medial wall and lateral wall are included.
Studies have shown that the balanced decompression has lower rates of diplopia as compared to decompressions involving the floor.
Initial management with digital repositioning 
If digital repositioning fails, a Desmarres retractor (or if not available, a large-sized paperclip, bent to form a right angle (similar to a laryngoscope)) can be used to navigate between the upper lid margin and superior rectus to allow for proper repositioning.
Lateral tarsorrhaphy or orbital decompression surgery may be necessary, if initial managements fail.
Patients at high risk for corneal exposure include those with a combination of proptosis, eyelid retraction, lagophthalmos, neurotrophic cornea, and poor Bell's reflex.
Pathogenesis is centered on prolonged exposure of corneal surface, leading to corneal drying, which decreases vision and threatens barrier to infection.
Treatment of non-emergent cases includes
Ocular surface lubrication
Increasing tear production via immunosuppression (cyclosporine, loteprednol, flurometholone)
Decreasing tear evaporation
Increasing oil content of tears
Omega-3 fatty acids
Decreasing surface area for exposure and evaporation with eyelid surgery
Lid retraction repair
Decreasing tear outflow (punctal plugs or cautery)
Treat emergent cases when corneal integrity is threatened.
The cause of the exposure must be corrected, and more aggressive therapy is pursued to provide protection and moisture in the meantime.
A bandage contact lens (BCL) or scleral contact lens with concomitant topical antibiotic will protect the cornea from further drying, while also preventing infection.
A temporary tarsorrhaphy may be indicated while pursuing other treatment modalities to decrease factors that exacerbate exposure, including
Ocular surface inflammation
Treatment of Non-Emergent Conditions
Proptosis (Figure 25)
Orbital decompression increases the volume of the bony orbit through removal of orbital bone and adipose tissue and allows a proptotic globe to recess back into its normal confines.
It is considered first-line therapy for cases of severe optic nerve compression.
Other indications include
Restoration of pre-morbid appearance in patients with residual proptosis following the active stage of TED
Because decompression surgery can alter globe positioning, decrease eyelid retraction, and affect extraocular motility, it should precede any extraocular muscle or eyelid surgery.
Orbital decompression can reduce proptosis and eyelid retraction .
Figure 25: Exophthalmos. The globe is displaced anteriorly out of the orbit. This is an ophthalmologic emergency – the cornea is at risk for exposure, and the optic nerve is at risk of irreversible damage.
TED affects extraocular muscles in a predictable manner .
The inferior rectus and medial rectus are most commonly involved.
This presents as hypotropia and/or esotropia.
Most TED patients with diplopia due to strabismus will not require surgical intervention, as most can be effectively managed with prism spectacles .