Faculty Bibliography

PURPOSE/OBJECTIVE:The purpose of this study is to review the current literature on keratoprosthesis and its use in the pediatric population. METHODS:Case report and review of recent literature on outcomes of pediatric keratoplasty and keratoprosthesis. RESULTS:Penetrating keratoplasty in children is fraught with shortcomings, including difficulty maintaining a clear graft (as low as 44% at 50 months), poor visual acuity outcomes (only 30-34% achieving 20/400 or better), and a high rate of allograft rejection (40-50%). Placement of the Boston type I keratoprosthesis has the advantage of achieving a clear visual axis and stable refractive error within days of surgery without risk of rejection. However, life-long care is required, including topical steroids and antibiotic prophylaxis, as well as bandage contact lens wear and a frequent a need for further interventions for retroprosthetic membranes and glaucoma. CONCLUSIONS:With motivated parents, a successful anatomic and functional outcome can be achieved with the Boston keratoprosthesis in children of amblyogenic age.

Riboflavin-induced ultraviolet light (UV) cross linking has received a significant amount of attention in recent years. It is currently approved in Europe as a treatment for keratoconus and is also being used for other corneal disorders. The goal of this paper is to review in detail seminal papers and studies that have been done to support cross linking as a safe and effective treatment for patients with early stages of keratoconus.

A healthy 10-year-old girl developed synchronous, bilateral, temporal redness of the eyes regarded as sectoral conjunctivitis for 5 years that was unresponsive to topical steroids and antihistamines. Finely vascularized, minimally elevated, amelanotic or faintly focally pigmented, epibulbar conjunctival lesions were present bilaterally. The lesions were completely excised. Histopathologic and immunohistochemical evaluations confirmed that they were both predominantly junctional nevi with conspicuous chronic inflammation. Juvenile conjunctival nevi frequently have atypical histopathologic traits that in an adult could be suggestive of melanoma. The differential diagnosis of much less likely disorders includes leukemia, lymphoid tumor (salmon patch), and conjunctival sarcoidosis, among other conditions. The patient has had no recurrence 3 years after surgery.

PURPOSE/OBJECTIVE:To present a case of a corneoscleral juvenile xanthogranuloma (JXG) with diagnostically challenging features. METHODS:A 15-year-old boy's small corneoscleral mass of recent onset was examined histologically and immunohistochemically. RESULTS:The biopsy had some superficially misleading histological and immunohistochemical features: S-100 positivity (however, observable in 30% of JXG lesions) and lack of Touton giant cells (often absent in early lesions). Most importantly, the histiocytes stained negatively for CD1a and strongly positively for both lysozyme and CD68 antigen. CONCLUSIONS:JXG is a benign histiocytic disorder that usually appears early in childhood but is also encountered in 13%-18% of cases in the second decade. The histiocytes usually stain positively for CD68 and negatively for S-100 and CD1a. Correctly distinguishing JXG from the more aggressive spectrum of Langerhans cell diseases (100% have CD1a positivity) is essential for patient treatment.

PURPOSE/OBJECTIVE:To describe an acquired, smooth white lesion of the caruncle and to underscore the role of subsurface keratinizing squamous epithelium in its formation. METHODS:Clinical photographic documentation, histopathologic evaluation, and immunohistochemical staining of an excised specimen from a 25-year-old woman. RESULTS:A cyst was found that was lined by keratinizing squamous epithelium without a keratohyaline layer (trichilemmal keratinization), typical of lesions of the pilosebaceous unit. A portion of the cyst's lining was replaced by granulomatous inflammation resulting from an earlier spontaneous partial rupture. Ki-67 immunolabeling demonstrated relatively few nuclei in S-phase (DNA synthesis) in comparison with the overlying epithelium, thereby suggesting an obstructive, nonproliferative cause for the cyst. CONCLUSION/CONCLUSIONS:A white caruncular lesion is a very rare finding according to the literature. It is most likely caused by a cyst lined by squamous epithelium elaborating trichilemmal-type keratin. A sebaceous gland duct was established as the source for the current lesion.

PURPOSE/OBJECTIVE:To report two cases of persistent epitheliopathy after treatment of conjunctival melanoma and review management options for this condition. METHODS:Case report and literature review. RESULTS:Persistent epitheliopathy, presumably resulting from limbal stem cell deficiency, is an uncommon complication of treatment of conjunctival malignant melanoma with surgical excision, cryotherapy, and mitomycin C. The Boston Ocular Surface Prosthesis was successful in improving vision, comfort, and epithelial status in our patients. CONCLUSION/CONCLUSIONS:Persistent epitheliopathy is a rare complication of treatment of conjunctival melanoma. The Boston Ocular Surface Prosthesis is a viable treatment option in this situation.

Electronic energy transfer plays an important role in many types of organic electronic devices. Forster-type theories of exciton diffusion provide a way to calculate diffusion constants and lengths, but their applicability to amorphous polymer systems must be evaluated. In this paper, the perylenediimide dye Lumogen Red in a poly(methyl methacrylate) host matrix is used to test theories of exciton motion over Lumogen Red concentrations (C(LR)'s) ranging from 1 x 10(-4) to 5 x 10(-2) M. Two experimental quantities are measured. First, time-resolved anisotropy decays in films containing only Lumogen Red provide an estimate of the initial energy transfer rate from the photoexcited molecule. Second, the Lumogen Red lifetime decays in mixed systems where the dyes Malachite Green and Rhodamine 700 act as energy acceptors are measured to estimate the diffusive quenching of the exciton. From the anisotropy measurements, it is found that theory accurately predicts both the C(LR)(-2) concentration dependence of the polarization decay time tau(pol), as well as its magnitude to within 30%. The theory also predicts that the diffusive quenching rate is proportional to C(LR)(alpha), where alpha ranges between 1.00 and 1.33. Experimentally, it is found that alpha = 1.1 +/- 0.2 when Malachite Green is used as an acceptor, and alpha = 1.2 +/- 0.2 when Rhodamine 700 is the acceptor. On the basis of the theory that correctly describes the anisotropy data, the exciton diffusion constant is projected to be 4-9 nm(2)/ns. By use of several different analysis methods for the quenching data, the experimental diffusion constant is found to be in the range of 0.32-1.20 nm(2)/ns. Thus the theory successfully describes the early time anisotropy data but fails to quantitatively describe the quenching experiments which are sensitive to motion on longer time scales. The data are consistent with the idea that orientational and energetic disorder leads to a time-dependent exciton migration rate, suggesting that simple diffusion models cannot accurately describe exciton motion within this system.

OBJECTIVE:To evaluate the role of immunohistochemical methods in the diagnosis of benign and malignant conjunctival melanocytic proliferations. DESIGN/METHODS:Retrospective immunohistopathologic study. METHODS:Paraffin-embedded tissue sections from 20 conjunctival nevi and 15 invasive melanomas were immunoreacted with antibodies against cellular antigens S-100 protein, MART-1, HMB-45, CD-45, and Ki-67 nuclear proliferation protein. RESULTS:All nevi immunostained moderately to strongly for S-100 protein and MART-1. Results for HMB-45 were negative in the middle and lower subepithelial portions of 18 of 20 lesions; it was usually only weakly positive within the superficial junctional zone. Only 1 melanoma did not stain positively for S-100; MART-1 and HMB-45 were positive in all lesions at some level of intensity. Ki-67 positivity was restricted to the junctional zone of nevi and was diffuse in melanomas. The mean Ki-67 proliferation indices were 1.89% for the nevi and 17.3% for the melanomas. CD-45 can help to highlight lymphocytes that immunostain with Ki-67. Melanomas in situ and atypical primary acquired melanoses had more than twice the Ki-67 proliferation counts of intraepithelial junctional nevocytes (P < .001) and more intense HMB-45 cytoplasmic staining than junctional zone nevocytes. CONCLUSIONS:S-100 and MART-1 were not useful in separating benign from malignant lesions. Results for nevus cells beneath the junctional zone were overwhelmingly negative for HMB-45 and Ki-67. Two nevi and all melanomatous nodules were positive for HMB-45 (P < .001). A higher Ki-67 proliferation index convincingly separated melanomas from nevi (P < .001). Immunostaining for HMB-45 and Ki-67 are valuable adjuncts to careful histopathologic evaluation in assessing benign and malignant conjunctival melanocytic tumors.

PURPOSE/OBJECTIVE:To describe a case of conjunctival malignant melanoma (MM) arising from primary acquired melanosis in a patient with neurofibromatosis type 1 (NF-1). METHODS:Case report and literature review. RESULTS:A 66-year-old woman with a history of NF-1 presented with extensive pigmentation of the left bulbar conjunctiva. Conjunctival biopsies demonstrated MM arising from primary acquired melanosis with atypia. Two excision and cryotherapy procedures did not completely eradicate the conjunctival pigment, which was then treated with topical mitomycin C. Subsequent biopsies and clinical examinations have revealed no remaining tumor. CONCLUSION/CONCLUSIONS:Conjunctival MM is uncommon in patients with NF-1 and can be successfully treated with excision, cryotherapy, and topical mitomycin C.