Creative solutions applied to reconstructive challenges

May 10, 2012

Despite the availability of a number of tried and true procedures for reconstructing the anophthalmic socket, in certain difficult cases, oculoplastic surgeons may find it is necessary to “think outside the orbit,” said John Ng, MD, MS.

Orlando, FL-Despite the availability of a number of tried and true procedures for reconstructing the anophthalmic socket, in certain difficult cases, oculoplastic surgeons may find it is necessary to “think outside the orbit,” said John Ng, MD, MS.

Delivering the Ruedemann Lecture during the annual meeting of the American Academy of Ophthalmology, Dr. Ng presented a series of cases to illustrate how he turned to some unusual techniques to rehabilitate unusual sockets so they would enable prosthesis wear.

“Management of an anophthalmic socket is a lifelong process requiring collaboration between surgeons and ocularists. There are a number of time-tested reconstruction procedures to use, and it is always best to stick to those that work best in your hands. However, sometimes the usual options are not feasible,” said Dr. Ng, associate professor, department of ophthalmology, Oregon Health & Science University, Portland.

“I have [tried to provide] some ideas that surgeons can extrapolate from to approach various challenging situations.”

The goals in reconstructing the anophthalmic socket are to create a comfortable socket that will allow successful prosthetic wear with good cosmesis and motility so that the patient is happy and self-confident. The components that contribute to the ideal socket and allow prosthesis motility include the bony structure, soft tissue volume, superior and inferior fornices, posterior conjunctival surface area, and symmetry of the lids, said Dr. Ng.

The cases he reviewed illustrated situations where there was inadequate bony volume, insufficient soft tissue volume, and poor vascularity affecting the lids.

One case involved a 19-year-old patient with congenital unilateral anophthalmia whose superior orbital rim was low and impeding prosthesis fitting. She had undergone multiple grafts using hard palate mucosa to reconstruct her fornices and was referred because of difficulty maintaining her conformer. Clinical findings also showed shallow upper and lower fornices and brow ptosis.

Since the patient had a pneumatized orbital roof and relatively high ethmoid and frontal sinus, Dr. Ng said he drew from experience performing orbital decompression to expand the orbit in cases of thyroid orbitopathy. Using a transcoronal approach, he removed the inner wall (orbital side) of the sinus and then drilled down to remove the rim and orbital roof. After also stripping away the mucosa from the sinus, he reconstructed the superior orbital rim using titanium mesh and placed a porous polyethylene onlay implant on the lateral rim. This enabled the patient to have a larger conformer that would stay in place. The brow asymmetry was addressed through a direct forehead lift with a skin graft used to add length to the hypoplastic upper lid.

“The lesson learned in this case is that congenital anophthalmos presents a lifetime challenge with multiple surgeries necessary. To address this problem, think about bony reconstruction in addition to soft tissue surgery,” Dr. Ng said.

A case of a 7-month-old patient referred for microphthalmos with a giant cyst causing entropion/ectropion, pain, and fussing represented a challenge due to insufficient orbital soft tissue volume. Rehabilitation for microphthalmos with cyst usually involves allowing the cyst to grow and stimulate orbit growth. Then, enucleation, cyst removal, and socket rehabilitation are performed.

However, in this patient, Dr. Ng said he removed the rapidly enlarging giant cyst to achieve pain control. Once it was removed, he found there was significant muscle and fat atrophy within the socket. He chose to use a dermis fat graft to fill the large soft tissue volume deficit, knowing that these grafts tend to grow. However, even using as large a graft as possible, the space could not be filled.

Dr. Ng sutured the graft in place like a drum head. Although a potential space was left behind the tissue, the graft grew over time and filled the socket. However, after 2.5 years, it had expanded so much that the ectropion recurred. Debulking was performed, and the child was fitted with a prosthesis.

Another child also had a cyst that was not causing discomfort or lid problems and was stimulating orbital growth. However, because of its superior location, the cyst was causing sectoral displacement of the conformer and hypoplasia of the superior fornix. Excision was required to prevent severe fornix contracture, which is difficult to repair if delayed, Dr. Ng said.

“The lesson learned for managing cases of microphthalmia with cyst is that cyst growth can be variable. Therefore, close monitoring is needed so that we can appropriately time cyst removal. In addition, surgeons should realize the child’s face is very adaptable and dermal fat grafts are a good option for volume replacement because they grow. However, good volume does not always translate into good lid development, and so we need to be attentive to that issue as well,” Dr. Ng said.

To illustrate a case involving vascular deficiency, Dr. Ng described his management of a 21-year-old soldier who sustained multiple facial fractures with foreign bodies and a ruptured right globe in a blast injury. When seen on referral, the soldier had already undergone repair of the orbit fracture with some foreign body removal, but he had a lateral canthal open wound in the orbit that would not heal. The eye was blind and it and the right upper lid were fixed to bone.

After being treated for fungal infection, the eye was enucleated and a porous polyethylene implant placed. A temporalis muscle flap was used to provide vascularization, bringing the muscle through a tunnel and reflected back over the repaired lateral rim and back into the lateral wall of the eye socket. Then, canthoplasty was performed to re-create the lateral canthal angle.

“The lessons learned here are first to look for and manage retained foreign body and infection. In addition, this case illustrates that temporalis muscle works well for vascularization of the soft tissue coverage,” said Dr. Ng.

Dr. Ng said he also used a temporalis flap to address the contracted socket in the first case where he had orbitalized the frontal sinus. The middle and anterior lamella were created with the temporalis muscle, and then a buccal mucosa membrane graft was used to line the posterior surface, lid margin, and angle. Lateral canthoplasty was performed to sharpen the angle and a Penrose drain was placed to form the lateral fornix.

"This case shows temporalis muscle flaps work well in contracted sockets to create a socket that can hold a prosthesis. However, these patients need to be very motivated because while this technique allows creation of the fornix and lids, the lids are stiff and the prosthesis and lids will be static,” he said.

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