Peter A. D. Rubin

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 Evolution of Endonasal Dacryocystorhinostomy

Dacryocystorhinostomy is an important treatment in the relief of tearing. Through the years, there have been several advances in this procedure. Once performed only from an external approach, the advent of rigid endoscopes and endoscopic instrumentation has made the endonasal approach a reality. Advantages of the endonasal approach include lack of a cutaneous incision and excellent visualization of intranasal pathology, which is often the cause of dacryocystorhinostomy failure. Preoperative evaluation including a detailed medical history, physical examination with office endoscopy, and imaging, as well as postoperative care are important. Surgical technique with detailed knowledge of intranasal anatomy and meticulous attention to hemostasis are critical. Endonasal laser-assisted dacryocystorhinostomy is also performed today, and special preoperative considerations and key features of the lasers available are important in the selection of a laser for tissue or bone ablation during the procedure. Endoscopic conjunctivodacryocystorhinostomy is performed today, and given the critical nature of proper length and placement of the Jones tube intranasally, provides the significant advantage of intranasal visualization. Endoscopic dacryocystorhinostomy in children is also performed today; however, challenges such as small nasal anatomy and maintenance of the intranasal osteomy postoperatively in a child are significant issues.

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.

Chronic maxillary atelectasis.

Chronic maxillary atelectasis is a descriptive term that refers to a persistent decrease in the sinus volume of the maxilla from inward bowing of the antral walls. Case reports with comparable clinical presentations have appeared sporadically in the literature; however, this disorder has remained poorly defined. The purpose of this study is to provide a formal definition of this condition by the establishment of diagnostic and staging criteria. A 10-year case analysis identified 22 adults, and a review of the literature revealed another 25. The average age at presentation in our study was 38.3 years. Most patients were symptomatic, and some presented with diplopia and hypoglobus. Inward bowing of the antral wall(s) and persistent opacification on computed tomography made the diagnosis. Chronic maxillary atelectasis was separated into three stages according to the degree of wall deformation. While most patients were symptomatic, a past history of absent or mild symptoms referable to the nose and sinuses was encountered more often in those patients with osseous wall deformation (p = .041). Mild or absent symptoms at the time of diagnosis should not be considered a negative risk factor for the development of facial deformity, especially if the sinus has features consistent with complete pneumatization. A middle meatal antrostomy appears to relatively safely correct the sinus problem, while orbital floor reconstruction for hypoglobus, found in stage III of the disease, can be accomplished effectively via a transconjunctival approach using a combination of bone allograft and porous polyethylene sheets.

Orbital cellulitis in children.

Ocular adnexal and orbital infections are more common in children than in adults. Children are also at greater risk of developing serious life-threatening complications from these infections. The orbital septum divides the soft tissues of the eyelid (preseptal space) from those of the orbit (postseptal space). Infections localized to the space anterior to the septum are classified as preseptal and those posterior to the septum are considered orbital. This classification not only is useful in assessing the anatomical extent of the infection but also has prognostic and therapeutic implications. Two other types of infections are orbital abscesses and mycotic infections. True orbital abscesses such as occur in the intraconal space are rare, whereas subperiosteal abscesses are relatively more frequent. Orbital abscesses can arise from preexisting cellulitis, or they may be the precursor of a full-blown orbital infection. Better understanding of the pathophysiological mechanisms of such infections and improvement in diagnostic studies has led to a reduction in the morbidity and mortality from these infections.

Orbital fractures in children.

Purpose To describe the demographics, etiologic factors, clinical presentations, and outcomes of orbital fractures in children. Methods This was a retrospective case series of 96 consecutive patients under 18 years of age with orbital fractures presenting to the Massachusetts Eye and Ear Infirmary, including both hospitalized and nonhospitalized patients. Results Orbital fractures in children were most frequently the result of sports, assault, or motor vehicle accident. The majority of patients did not require hospitalization and were treated as outpatients. The medial wall and floor of the orbit were the most frequent locations of fracture. Approximately half of the patients in this series required surgery, most often for entrapment. There were no cases of persistent diplopia in patients in whom surgery was performed or was not indicated. Associated ocular injuries were observed in half of the patients. Conclusions In this series of hospitalized and nonhospitalized patients, orbital fractures in children had a location pattern similar to that most frequently observed in adult patients (floor and medial wall). Orbital fractures in children frequently require surgery. The high prevalence of ocular injury in children with orbital fractures emphasizes the need for a comprehensive ophthalmic evaluation.

Projectile metallic foreign bodies in the orbit: a retrospective study of epidemiologic factors, management, and outcomes.

PURPOSE Intraorbital projectile metallic foreign bodies are associated with significant ocular and orbital injuries. The authors sought to evaluate epidemiologic factors, the incidence of associated ocular and orbital injury, and the nature and necessity of surgical intervention in these cases. METHODS Charts of all patients with projectile intraorbital metallic foreign bodies seen at our institution (27) over the preceding 7 years were evaluated with respect to age, sex, type of injury, associated ocular and orbital injuries, location of the projectile (anterior, epibulbar, or posterior), postinjury visual acuity, and surgical intervention. RESULTS The majority of patients were male, between the ages of 11 and 30, and had BB pellet injuries. Thirteen projectiles were lodged anteriorly, 4 were in an epibulbar position, and the remaining 10 were posterior to the equator. Twelve of 13 anterior, and 4 of 4 epibulbar foreign bodies were removed surgically, whereas only 2 of 10 posterior foreign bodies required surgery. No case of surgical intervention resulted in a decrease of visual acuity. Associated ocular injuries were both more common and severe in patients with posteriorly located foreign bodies. Final visual acuity was better at presentation and at discharge in patients with anteriorly located foreign bodies. CONCLUSION Intraorbital projectile metallic foreign bodies can be a source of significant ocular morbidity. Management of these cases is dependent on the location of the projectile. Ancillary radiographic studies can be helpful. Surgery to remove the projectile should be considered in each case, but foreign bodies that are not readily accessible often may be left safely in place. Closer regulation of the pellet gun industry, with an emphasis on education and protective eyewear use, would be helpful in reducing these injuries.

Silicone punctal plug migration resulting in dacryocystitis and canaliculitis.

Purpose One of the modalities of treating dry eyes is punctal plugs. They are usually used for temporary occlusion of the lacrimal drainage system. Among the complications associated with silicone punctal plugs are extrusion, downward migration, irritation, and epiphora. To our knowledge, this is the first report of dacryocystitis and canaliculitis as a result of spontaneous migration of punctal plugs into the lacrimal drainage system. Methods We describe the sequelae of spontaneous migration of silicone punctal plugs into the lacrimal drainage system in two patients with dry eyes. Results In two patients, spontaneous migration of silicone punctal plugs into the canaliculus or the lacrimal sac, respectively, resulted in canaliculitis or dacryocystitis. Conclusion Smaller sized newer generation punctal plugs were designed to facilitate insertion; however, this design also increases the likelihood of proximal migration within the lacrimal drainage system. The importance of monitoring patients after punctal-plug placement cannot be overemphasized.

Repair of orbital blow-out fractures with nasoseptal cartilage

The goals of reconstruction in orbital blow‐out fractures are to restore floor continuity, provide support of orbital contents, and prevent fibrosis of soft tissues. Although ease of use has popularized alloplasts, autogenous material provides greater biocompatibility and results in low rates of infection, extrusion, and migration. Nasoseptal cartilage is an easily accessible, abundant, autogenous source that provides support to the orbital floor and minimal donor site morbidity. Thirteen patients who presented with orbital blow‐out fractures underwent reconstruction with nasoseptal cartilage. Follow‐up at 3 months to 4 years shows one patient with persistent manifest enophthalmos requiring further augmentation. There were no recipient or donor site complications. Nasoseptal cartilage is an underutilized and superior material for reconstruction of orbital blow‐out fractures.