An animal model of lower eyelid spacer grafting with acellular dermis.

PURPOSE: Lower eyelid retraction is common in patients with dysthyroid orbitopathy and is seen less commonly in other conditions. Treatment typically requires vertical augmentation of the posterior eyelid lamella with an interpositional graft. Several autologous, homologous, and alloplastic materials have been used. We investigated the gross and microscopic in vivo histology of acellular homologous dermis used as a structural interpositional graft in the lower eyelids of Yucatan minipigs. METHODS: This prospective, experimental study was designed as follows: Surgery was performed on the left lower eyelid of 4 Yucatan minipigs in accordance with the Massachusetts General Hospital Subcommittee on Research Animal Care guidelines. A 4 x 20-mm strip of acellular porcine dermis was prepared and sutured into place between the tarsus and conjunctiva/lower lid retractors. Tissues were harvested at 6 and 12 weeks and were evaluated histologically. RESULTS: Gross examination revealed vertical elongation of the palpebral conjunctival surface. Histologic evaluation was performed with hematoxylin and eosin and Verhoeff elastin stains. Serial sections demonstrated incorporation of grafted dermal matrix into native tissues without evidence of inflammation. Definitive differentiation between grafted dermis and native dermis was not possible with light microscopy. Portions of the graft appeared to be epithelialized, whereas other histologic regions showed poorly adhesive epithelium. Inflammatory infiltrates including lymphocytes and polymorphonuclear leukocytes were not seen. No epithelioid or giant cells were identified in the sections examined. CONCLUSIONS: Acellular homologous dermis produced no measurable untoward effects when implanted as an interpositional graft in the lower eyelid of Yucatan minipigs. On the basis of its material characteristics, it appears to be suitable for this purpose: It is readily available, easily stored, easy to manipulate, and produces minimal inflammation. Long-term persistence, early postoperative histology, and clinical eyelid elevation in humans remain to be evaluated.

Primary placement of a motility coupling post in porous polyethylene orbital implants.

The placement of a motility coupling post (MCP) to integrate the prosthesis with a porous orbital implant may enhance prosthetic motility following enucleation. Previously, MCP placement has required a second operation usually at least 6 months following enucleation. We developed a technique to place an MCP reliably and safely into a porous orbital implant at the time of enucleation. Eligibility criteria included high motivation to achieve maximal prosthetic motility, adequate conjunctiva to ensure desirable wound closure, and isolation of the 4 rectus muscles. Enucleation was performed in standard fashion with implantation of a conical porous polyethylene orbital implant. Implanted MCPs protruded anteriorly 2 to 4 mm. The Tenon capsule and conjunctiva were closed in separate layers over the protruding MCP. Thirty-two patients underwent primary placement. Follow-up ranged from 1 to 33 months (mean, 15 months). Nine MCPs spontaneously exposed within the first 4 months. One additional post autoexposed at 12 months. Three patients underwent a secondary procedure to expose the MCP. There were no cases of infection, explantation, or gross MCP malposition. Minor complications included pyogenic granuloma (n=2) and conjunctival overgrowth (n=1). All patients were successfully fit with prostheses. Prosthetic motility was acceptable in all patients. Motility coupling post placement at the time of enucleation surgery in selected patients is an effective, efficient surgical option. Arch Ophthalmol. 2000;118:826-832

Ophthalmic plastic applications of acellular dermal allografts.

PURPOSE: Clinical problems of contracted conjunctival fornices, superior sulcus defects, and soft tissue contour defects in the periorbital region have not shown good, sustained results with a range of autologous and alloplastic implants. AlloDerm (Lifecell Corp., Woodlands, TX) is an acellular dermal graft processed from human donor tissue. The authors sought to assess the efficacy of AlloDerm as a soft tissue replacement in a variety of oculoplastic applications. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Twenty-three patients. METHODS: Applications were broadly classified as barrier/scaffolding (i.e., primary and secondary implant coverage, lid spacer graft) and volume augmentation (i.e., superior sulcus and other periorbital soft tissue contour defects). Barrier grafts were applied as single sheets. Stacked sheets or rolled grafts were used for augmentation. Collectively, this material was used in 29 cases with 3 to 16 months' follow-up. MAIN OUTCOME MEASURES: Clinical evaluation of outcome and complications. RESULTS: As a soft tissue scaffolding and barrier implant, AlloDerm persisted sufficiently to permit repopulation with native tissue. Rolled/stacked implants demonstrated unpredictable resorption. Upper eyelid grafts seemed to have higher resorption rates than lower eyelid grafts. One case of anophthalmic superior sulcus augmentation required two revision surgeries to provide sufficient volume augmentation. The grafts were well tolerated, with no cases of infection or explanation. CONCLUSION: Acellular human dermis is an excellent barrier and reconstructive grafting material that provides an alternative to autologous grafts and other alloplastic material, avoids harvesting autologous tissue, possesses excellent handling properties, and is associated with minimal inflammation. Long-term follow-up is required to evaluate persistence.

Multiple myeloma involving the orbit.

Multiple myeloma is a plasma cell malignancy often associated with destructive skeletal lesions. Orbital involvement in multiple myeloma is rare. Risk factors for orbital involvement have not been established, although risk may vary with immunoglobulin subtype. Early detection of orbital plasmacytoma may affect treatment and clinical course. A case is reported of multiple myeloma without elevated serum immunoglobulins that involves the orbit, and the implications of early detection are discussed. The patient was first examined by an ophthalmologist 13 months after multiple myeloma was diagnosed and 5 months after the external appearance of an orbital tumor. Urine protein electrophoresis demonstrated kappa light chains. Hypergammaglobulinemia was not detected. Plain-film roentgenography showed orbital involvement at the time of initial diagnosis. An impressive clinical response to external beam radiation therapy was seen. Attention to immunoprotein characteristics in multiple myeloma may help to identify risk factors for orbital involvement. Early detection may permit safer and equally effective treatment. All patients with multiple myeloma should undergo thorough ophthalmic examination at the time of initial diagnosis.

Magnetic resonance imaging of optic perineuritis.

Optic perineuritis, an uncommon variant of orbital pseudotumor, may be clinically indistinguishable from retrobulbar optic neuritis. Because treatment and prognosis for these two entities are different, early diagnosis is important. We report a case of a 47 year-old woman with clinical findings suggestive of retrobulbar optic neuritis, but whose magnetic resonance images suggested optic perineuritis. A dramatic clinical response to oral corticosteroids was observed. Optic perineuritis should be considered in cases of presumed retrobulbar optic neuritis. MRI may differentiate these two entities in the acute stage, and should be considered before treatment is decided.

Dapsone-induced neutropenia in patients treated for ocular cicatricial pemphigoid.

BACKGROUND: Dapsone is used widely in treating ocular cicatricial pemphigoid, leprosy, and dermatologic disorders. Hemolysis is a well-known complication of dapsone therapy. Rarely, neutropenia or agranulocytosis may occur, resulting in up to a 50% mortality rate. To the authors' knowledge, agranulocytosis has not been reported in patients treated with dapsone for ocular cicatricial pemphigoid. METHODS: The authors report two cases of dapsone-induced neutropenia with bone marrow suppression in patients with ocular cicatricial pemphigoid. RESULTS: Neutropenia was detected on routine laboratory examination 8 and 10 weeks after initiating dapsone therapy. Bone marrow biopsy showed acellular or hypocellular marrow. Leukocyte count returned to baseline value after cessation of dapsone. CONCLUSION: Patients with ocular cicatricial pemphigoid who were treated with dapsone are at increased risk for agranulocytosis. Dapsone-induced neutropenia may not be a dose-dependent phenomenon. The authors indicate that there is a need for routine monitoring of leukocyte counts, especially 8 to 10 weeks after initiating therapy. Signs or symptoms of infection require immediate investigation.

Pupil diameter and the principal ray.

Placement of the surgical zone is critical in refractive procedures that alter a portion of the corneal curve. An improperly centered optical zone may produce glare, decrease best corrected visual acuity, and decrease contrast sensitivity. For proper placement, the new surface should be centered around the line of sight, which is the principal ray from the object of regard that passes through the image of the patient's pupil as projected on the cornea. This point is not necessarily at the geometric center of the cornea and is found by locating the center of the pupil while the patient is maintaining fixation coaxially with the surgeon. However, the pupil does not dilate concentrically and its geometric center moves as the pupil diameter changes. We have found a shift up to 0.7 mm in the geometric center of the pupil as it dilates. Therefore, centration of an ablated or a radial keratotomy zone is most efficiently done when the diameter of the modified corneal optical zone is centered around the line of sight and is superimposed upon the entrance pupil. This will minimize extension of the edge of the large pupil beyond the ablated zone and reduce unwanted secondary optical effects from degrading vision.