John W. Shore

Orbital Reconstruction Using Porous Polyethylene Sheets

BACKGROUND There has been growing interest in using porous alloplastic implants for reconstructive orbital surgery because of their perceived increased biocompatibility. One commercially available porous implant is high-density porous polyethylene (Medpor). It is made of pure particles of polyethylene that form interconnecting pores and have excellent handling characteristics. METHODS The authors performed 37 orbital reconstructions using 0.85-, 1.5-, or 3-mm porous polyethylene sheets to reconstruct internal orbital defects. Mean postoperative follow-up was 18.5 months. Four patients were treated for anophthalmic enophthalmos; there was one patient with spontaneous enophthalmos. In selected patients, other implants also were used, including miniplates or microplates, silastic sheets, autologous bone, or nasal septal cartilage. In patients with enophthalmos, the implants were stacked to reverse the malposition evident at surgery. RESULTS Preoperatively, 27 patients had symptomatic diplopia. Postoperatively, the diplopia resolved in 15 patients and decreased in 7. No patients had induced diplopia or exacerbation of preoperative diplopia. Enophthalmos resolved in 9 of 18 patients. Hypoglobus was normalized in nine of nine patients. There was one major complication of orbital infection requiring explantation 1 week postoperatively. Minor complications included undercorrection, a symptomatically palpable implant, and transient postoperative chemosis. CONCLUSION Porous polyethylene sheets offer several distinct advantages when used for orbital reconstruction. They are easy to handle, shape, contour, position, fixate, and use with other autogenous and alloplastic implants. In this series, these sheets permitted predictable, stable results with few complications.

Comparison of fibrovascular ingrowth into hydroxyapatite and porous polyethylene orbital implants

Two porous orbital implants available for clinical use in the anophthalmic socket are hydroxyapatite (HA) and porous polyethylene (PP). We examined the rate and the extent of fibrovascular ingrowth into these implants using histopathologic criteria in a rabbit model. Thirty-two New Zealand white rabbits underwent a unilateral enucleation with placement of a 14-mm spherical orbital implant. Twelve rabbits received HA, 12 small-pore PP, and 8 large-pore PP. The implants inserted were wrapped either in autologous sclera with and without anterior fenestrations or as unwrapped spheres. The implants were harvested at 6 and 12 weeks. The extent of fibrovascular ingrowth was assessed by determining the percentage of the cross-sectional area penetrated by fibrovascular tissue. On gross inspection, 12 implants (37.5%) were found to be exposed at harvesting; however, only two were grossly infected. The highest rate of exposure was found among the unwrapped implants. Wrapped versus unwrapped and fenestrated versus unfenestrated implants did not result in significant differences in the extent of vascularization. Hydroxyapatite implants were vascularized most rapidly. The small-pore PP implants did not become fully vascularized during the study, and yet complete vascularization was found in the large-pore PP at 12 weeks. The most intense areas of microscopic fibrovascular ingrowth were in the region where the extraocular muscles were in direct contact with the implant and at the posterior opening. Exposure of the implant was accompanied by chronic and acute inflammation. Both HA and large-pore PP spherical implants are capable of complete vascularization in this animal model. Increasing the interstitial pore size resulted in more complete vascularization of the PP. Vascularization of the implants is limited by exposure, secondary inflammation, and infection.

The porous polyethylene (Medpor) spherical orbital implant: a retrospective study of 136 cases.

Purpose To evaluate complications and risk factors associated with the placement of wrapped and unwrapped porous polyethylene (PP) spherical implants after evisceration, enucleation, or secondary implantation. Methods A retrospective, interventional, noncomparative case series of consecutive cases of PP implant placement after anophthalmic socket surgery performed by three surgeons over a 5-year period. A PP spherical implant was placed in 133 patients, 61 women (2 bilaterally) and 72 men (1 bilaterally). There were 91 enucleations, 30 eviscerations, and 15 secondary implant placements. Sixty-six (48.5%) implants were wrapped prior to placement. Parameters evaluated included: age, sex, prior ocular surgery or radiation treatment, indications for surgery, procedure performed, size of PP sphere, material used to wrap the implant, and complications. Results A total of 17 of 136 (12.5%) cases had documented postoperative complications, with implant exposure being the most common. In 5 patients (3.7%), implant exposure developed: 1 after evisceration and 4 after primary enucleation. Three of the five exposures were small and resolved with either observation alone or in one case with surgical revision of the socket. In two cases, the exposures were large enough that removal of the implant was indicated, one after evisceration and the other after enucleation with placement of a wrapped PP sphere. Conclusions Our series revealed no significant difference in exposure rate between wrapped and unwrapped PP sphere implants, nor was the exposure rate affected by whether an eye was eviscerated or enucleated.

The spectrum of orbital aspergillosis : A clinicopathological review

Orbital aspergillosis is an uncommon but serious infection that may first present to the ophthalmologist. Usually arising from the paranasal sinuses, it may present in manifold ways within the orbit. Some presentations, such as optic nerve involvement, can respond to systemic corticosteroids, leading to delays in diagnosis and possibly iatrogenic potentiation of the infectious process. In this review, pertinent clinical and radiographic findings are discussed, and the literature is summarized. Classic approaches to therapy include local treatment, debridement, and systemic amphotericin B. We review novel approaches to treating orbital aspergillosis and detail a flow-chart for its management. Four patients from the spectrum of orbital aspergillosis are also described: initially presenting as an infection of an exenteration socket, a complex dacryocystitis, and optic nerve tumor, and post-operative periorbital swelling. Physicians should be familiar with the clinical spectrum of disease and the variable presentation of this infection, as early diagnosis and rapid institution of appropriate therapy are crucial elements in the management of invasive aspergillosis. In the neutropenic or otherwise immunocompromised patient, a high index of suspicion must be maintained as delays in diagnosis of fulminant aspergillosis may lead to overwhelming and rapidly progressive infection. Obtaining adequate diagnostic material for pathological and microbiological examination is critical. Newer methods of therapy, particularly itraconazole and liposomal amphotericin B, may be beneficial in selected patients.

Results of Buccal Mucosal Grafting for Patients with Medically Controlled Ocular Cicatricial Pemphigoid

Eyelid surgery for patients with ocular cicatricial pemphigoid is risky when there is unchecked perioperative inflammation. The authors performed buccal mucosal grafts on 42 eyelids (23 eyes) of 17 patients with ocular cicatricial pemphigoid whose disease was controlled by systemic immunosuppression. Results were graded as: improved (12 cases, 16 eyes); satisfactory (2 cases, 2 eyes); or poor (5 patients, 5 eyes). Complications included breakthrough trichiasis, surface keratinization of the graft, blepharoptosis, phimosis, depressed eyelid blink, incomplete eyelid closure, submucosal abscess formation, and persistent nonhealing epithelial defects of the cornea. Technical errors at surgery accounted for two complications. Secondary corneal ulceration developed in two patients. The immunologic aspect of the disease flared or progressed in five patients in the postoperative period and necessitated an increase or change in systemic medication for immunosuppression. Buccal mucosal grafting shows promise in temporarily rehabilitating eyelids of some ocular cicatricial pemphigoid patients whose disease is controlled by immunosuppressive therapy.

Histopathologic Features of the Floppy Eyelid Syndrome: Involvement of Tarsal Elastin

Purpose: Patients with the floppy eyelid syndrome have chronic papillary conjunctivitis with easily everted upper eyelids and a soft, pliant upper tarsus. The purpose of this study is to describe the clinical features and the histopathologic correlate in a group of patients with floppy eyelid syndrome. Methods: The authors examined eight patients with floppy eyelid syndrome, four of whom underwent surgical management with horizontal eyelid shortening. Eyelid tissue from these patients was examined using light microscopy, electron microscopy, and immunohistochemistry and compared with controls with unrelated eyelid or orbital disorders. Results: Clinical findings included obesity or eye rubbing, lash ptosis, and, less commonly, blepharoptosis. Two patients had documented sleep apnea with abnormal sleep electroencephalogram. Light microscopy of the surgical specimens showed chronic conjunctival inflammation, papillary conjunctivitis, and meibomian gland abnormalities, including granuloma formation. Verhoeffs modified elastin stain demonstrated a marked decrease in the amount of elastin fibers in tarsus from patients with floppy eyelid syndrome compared with controls. Immunohistochemical staining for elastin also showed a marked decrease of tarsal elastin in floppy eyelid patients compared with controls. In contrast, immunohistochemical stains showed that the distribution of collagen types I and III was similar between patients with floppy eyelid syndrome and controls. Electron microscopy demonstrated that tarsal collagen was comparable in patients and controls, and that there was a reduced amount of tarsal elastin in floppy eyelid syndrome compared with controls. Conclusions: These findings demonstrate that tarsal elastin is decreased in the floppy eyelid syndrome, which may contribute to the laxity of the tarsus in this disorder.

Operative Complications of the Transconjunctival Inferior Fornix Approach

The transconjunctival inferior fornix incision provides access to the floor, rim, lateral, and inferior medial walls of the orbit. Complications of this surgical approach to the orbit are known to be rare but heretofore have not been clearly defined. Over an 8-year period, in an estimated 1200 cases, the authors have encountered cicatricial entropion, lower eyelid retraction, canthal dehiscence, lower eyelid avulsion, canalicular laceration, buttonhole laceration of the lower eyelid, conjunctival chemosis, and lacrimal sac laceration. Attention to anatomic landmarks and sound surgical execution will prevent these complications in most patients.

Anatomic Changes in Involutional Blepharoptosis

Involutional blepharoptosis is a degenerative process involving the levator aponeurosis. Clinical and histopathologic evidence for involvement of the levator palpebrae superioris muscle has not been firmly established. We examined 20 patients with involutional blepharoptosis who demonstrated additional clinical, anatomic, and histopathologic findings consisting of a dehiscence of the medial limb of Whitnalls ligament, a lateral displacement of the tarsal plate of the upper eyelid, and a fatty degeneration of the levator muscle in the area of Whitnalls ligament. These findings suggest that a primary myopathic process may be involved in some cases of involutional blepharoptosis. The tarsal displacement complicates surgical correction of eyelids with blepharoptosis secondary to this myopathic process.

A spectrum of bilateral squamous conjunctival tumors associated with human papillomavirus type 16

Three patients with bilateral tumors presenting as multiple keratinizing and verrucous lesions of the bulbar and tarsal conjunctiva were determined by DNA amplification and hybridization studies to harbor human papillomavirus type 16 (HPV-16). Results of biopsy in two patients showed infiltrating squamous cell carcinoma in one eye and dysplasia or carcinoma in situ in the fellow eye. In the third patient, focal, inflamed, hypertrophic, papillary lesions with pseudoglandular invaginations of the surface epithelium were found in the tarsal conjunctivae of both eyes. These are the first documented cases of bilateral conjunctival tumors associated with human papillomavirus.

Linear Nevus Sebaceous Syndrome

The linear nevus sebaceous syndrome is a rare disorder first described in 1962 in two cases by Feuerstein and Mims. As originally described, it consisted of the triad of the characteristic midline facial linear nevus sebaceous of Jadassohn, seizures, and mental retardation. The authors have followed a patient with this syndrome from birth to age 8 and although he does demonstrate several neurologic and ocular abnormalities, he enjoys normal intelligence and has never suffered seizures. The features of this syndrome and several new ocular findings demonstrated in this case are described. Based on our long-term follow-up of this patient and our review of the reported cases to date, the authors suggest that the triad for this disorder should be changed to include the midline facial linear nevus sebaceous of Jadassohn, neurologic abnormalities which may, but not necessarily, include seizures and mental retardation, and ophthalmologic abnormalities.