Faculty Bibliography

PURPOSE/OBJECTIVE:To compare the anatomy of the graft-host junction and anterior chamber angle after Boston Keratoprosthesis (KPro) placement using oversized (9.5-mm) and standard (8.5-mm) back plates. METHODS:Six patients with 9.5-mm titanium back plates and 10 patients with 8.5-mm titanium back plates were imaged by anterior segment optical coherence tomography 6 to 12 months after KPro placement. The location of the graft-host junction in relation to the back plate, the corneal thickness at the graft-host junction, and the anterior chamber angle were assessed. The clinical outcomes and incidence of retroprosthetic membrane (RPM) formation in this cohort were retrospectively evaluated. RESULTS:The oversized back plates completely covered the graft-host junction in all quadrants, allowing the complete apposition of the posterior surface of the carrier graft with the host cornea, with decreased graft-host junction wound thickness. The standard back plates covered the posterior aspect of the carrier graft but not the graft-host junction or the host cornea, resulting in a significantly thicker graft-host junction. None of the patients with larger back plates developed a significant RPM during a 12-month follow-up period. One patient with a larger back plate developed a corneal melt at the KPro stem as a result of chronic exposure. CONCLUSIONS:Oversized KPro back plates effectively cover the graft-host junction without any adverse effects on angle anatomy or wound healing. This may be a strategy to provide better wound apposition, reduce RPM formation, and reduce angle closure from iris synechiae to the wound.

PURPOSE/OBJECTIVE:To evaluate clinicopathologically and immunohistochemically a spectrum of conjunctival squamous proliferations. DESIGN/METHODS:Retrospective clinicopathologic study. METHODS:One large cell acanthoma, 7 epidermoid dysplasias, and 4 squamous papillomas were evaluated with microscopy and biomarkers Ki-67, p53, epithelial membrane antigen (EMA), Ber-EP4, AE1, AE3, and 8 individual cytokeratins. Normal associated conjunctiva served as a baseline for interpretation. RESULTS:The large cell acanthoma recurred 4 times but retained its benign histopathologic features. The cells were 2-3 times larger than the keratinocytes of the normal conjunctiva and did not display atypia. Immunohistochemistry revealed a low Ki-67 proliferation index (PI) in the large cell acanthoma compared with high indices in dysplasias and papillomas. p53 was negative in the nuclei of normal epithelium while positive in all neoplasms, most intensely in the dysplasias. Immunostaining showed similar staining patterns for cytokeratins in large cell acanthoma and normal conjunctiva, except for full-thickness CK14 positivity and CK7 negativity in the lesion. Dysplasias generally lost normal CK7 expression and frequently abnormally expressed CK17. The papillomas displayed a normal cytokeratin pattern but exhibited a higher than normal PI and weak p53 positivity. CONCLUSIONS:Conjunctival large cell acanthoma is a morphologically distinctive clonal entity with clinical and immunohistochemical phenotypic characteristics denoting a dysplasia of minimal severity. Because of recurrences without invasion, it requires treatment. Dysplasias exhibited more deviant biomarker abnormalities including frequent aberrant full-thickness CK17 positivity and CK7 negativity. The absence of major cytokeratin derangements in the squamous papillomas may be of ancillary diagnostic value for lesions displaying borderline cytologic features.

PURPOSE/OBJECTIVE:To demonstrate the value of a diagnostic biopsy of a fixed episcleral nodule overlying a uveal mass. METHOD/METHODS:Clinicopathologic report with immunohistochemical investigations. RESULTS:B-scan ultrasonographic biomicroscopy disclosed in a 67-year-old man an asymptomatic placoid ciliary body tumor measuring 1.28 mm in thickness underlying a poorly pigmented, fixed episcleral nodule 0.56 mm in thickness. Biopsy of the episcleral nodule displayed benign nevus-type spindle cells with small nuclei, punctate nucleoli, no mitoses, and scattered melanophages. Immunohistochemistry demonstrated that the tumor cells were Ki67 negative (proliferation index, 0) and MART-1, HMB-45, and microphthalmia-associated transcription factor positive, all melanocytic markers. The melanophages but not the tumor cells were CD68 positive, a histiocytic marker. CONCLUSIONS:The results from biopsying an episcleral nodule can help to select among therapeutic options in managing an associated ciliary body tumor. A 1-year follow-up study and 3 sequential ultrasonographic studies in the current patient have failed to document the growth of the intraocular tumor, further confirming that it is a nevus. The excised epibulbar tumor has not recurred.

Aniridia classically presents with a bilateral congenital absence or malformation of the irides, foveal hypoplasia, and nystagmus, and patients tend to develop visually significant pre-senile cataracts and keratopathy. Additionally, they are at high risk for developing glaucoma. Classic aniridia can be genetically defined as the presence of a PAX6 gene deletion or loss-of-function mutation that results in haploinsufficiency. Variants of aniridia, which include a condition previously referred to as autosomal dominant keratitis, are likely due to PAX6 mutations that lead to partial loss of PAX6 function. Aniridia-associated keratopathy (AAK) is a progressive and potentially debilitating problem affecting aniridic patients. The current treatments for AAK are to replace the limbal stem cells through keratolimbal allograft (KLAL) with or without subsequent keratoplasty for visual rehabilitation, or to implant a Boston type 1 keratoprosthesis. Future therapies for AAK may be aimed at the genetic modification of corneal limbal stem cells.

PURPOSE/OBJECTIVE:To describe the clinical characteristics, treatment, and outcomes of herpes simplex virus (HSV) infections of the cornea and adnexae to raise awareness and to improve management of this important eye disease in children. DESIGN/METHODS:Retrospective case series. PARTICIPANTS/METHODS:Fifty-three patients (57 eyes) 16 years of age or younger with HSV keratitis (HSK), HSV blepharoconjunctivitis (HBC), or both in an academic cornea practice. METHODS:The following data were collected: age at disease onset, putative trigger factors, coexisting systemic diseases, duration of symptoms and diagnoses given before presentation, visual acuity, slit-lamp examination findings, corneal sensation, dose and duration of medications used, drug side effects, and disease recurrence. MAIN OUTCOME MEASURES/METHODS:Presence of residual corneal scarring, visual acuity at the last visit, changes in corneal sensation, recurrence rate, and manifestations of HSK were assessed in patients receiving long-term prophylactic systemic acyclovir. RESULTS:The median age at onset was 5 years. Mean follow-up was 3.6 years. Eighteen eyes had HBC only; 4 patients in this group had bilateral disease. Of 39 eyes with keratitis, 74% had stromal disease. Thirty percent of HSK cases were misdiagnosed before presentation. Seventy-nine percent of patients with keratitis had corneal scarring and 26% had vision of 20/40 or worse at the last visit. Eighty percent of patients had recurrent disease. Six of 16 patients (37%) receiving long-term oral acyclovir had recurrent HSV, at least one case of which followed a growth spurt that caused the baseline dosage of acyclovir to become subtherapeutic. CONCLUSIONS:In a large series, pediatric HSK had a high rate of misdiagnosis, stromal involvement, recurrence, and vision loss. Oral acyclovir is effective, but the dosage must be adjusted as the child grows.

PURPOSE/OBJECTIVE:To describe the trend of Acanthamoeba keratitis case reports following an outbreak and the recall of a multipurpose contact lens disinfection solution. Acanthamoeba keratitis is a serious eye infection caused by the free-living amoeba Acanthamoeba that primarily affects contact lens users. METHODS:A convenience sample of 13 ophthalmology centers and laboratories in the USA, provided annual numbers of Acanthamoeba keratitis cases diagnosed between 1999-2009 and monthly numbers of cases diagnosed between 2007-2009. Data on ophthalmic preparations of anti-Acanthamoeba therapies were collected from a national compounding pharmacy. RESULTS:Data from sentinel site ophthalmology centers and laboratories revealed that the yearly number of cases gradually increased from 22 in 1999 to 43 in 2003, with a marked increase beginning in 2004 (93 cases) that continued through 2007 (170 cases; p < 0.0001). The outbreak identified from these sentinel sites resulted in the recall of a contact lens disinfecting solution. There was a statistically significant (p ≤ 0.0001) decrease in monthly cases reported from 28 cases in June 2007 (following the recall) to seven cases in June 2008, followed by an increase (p = 0.0004) in reported cases thereafter; cases have remained higher than pre-outbreak levels. A similar trend was seen in prescriptions for Acanthamoeba keratitis chemotherapy. Cases were significantly more likely to be reported during summer than during other seasons. CONCLUSION/CONCLUSIONS:The persistently elevated number of reported cases supports the need to understand the risk factors and environmental exposures associated with Acanthamoeba keratitis. Further prevention efforts are needed to reduce the number of cases occurring among contact lens wearers.

Ocular imaging technologies continue to evolve and play increasingly important roles in both the diagnosis and management of corneal pathology. In addition to improved documentation of exam findings using increasingly better resolution photographs, newer modalities, including specular and confocal microscopy, can facilitate diagnosis by imaging single cell layers within the cornea. Anterior segment optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) can image structures in the cornea and anterior segment which may not otherwise be visible. This is particularly useful in patients with opaque corneas. The ability to topographically map the cornea allows for more accurate pre- and post-operative planning, especially in patients with corneal ectasia. As these technologies develop, their use in specific patient populations, such as children, must be optimized. In this report, we provide an updated analysis of selected imaging modalities used in the diagnosis and management of pediatric corneal pathology.

BACKGROUND/PURPOSE/OBJECTIVE:To compare the rate of retroprosthetic membrane (RPM) formation in Boston Keratoprosthesis (BKPro) with polymethyl methacrylate (PMMA) versus titanium backplates. DESIGN/METHODS:Retrospective comparative chart review. METHODS:Multicenter study population: a total of 78 eyes with keratoprosthesis implants with either PMMA or titanium backplates were included in the study. To be included in the study, all subjects had to have completed a minimum of 6-month follow-up period. Incidence of RPM development at 6-month postoperative period was noted across the study population. PMMA and titanium backplates were then compared by their rate of association with subsequent RPM. RESULTS:Twenty-three out of 55 eyes (41.8%) with PMMA backplates and three out of 23 eyes (13.0%) with titanium backplates had developed an RPM at 6 months after implantation. The titanium backplates were associated with significantly less RPM formation than PMMA backplates (p = 0.014, Chi-square test). CONCLUSIONS:Titanium seems to be associated with less RPM formation than PMMA when used as a material for the BKPro back plate.

In this paper, we continue our evaluation of Forster-type theories of exciton diffusion in disordered environments. The perylenediimide dye Lumogen Red is used as a donor molecule in two different liquids, CHCl(3) and dimethylformamide, and the energy transfer to the acceptor molecule Rhodamine 700 is measured using time-resolved fluorescence decays. The exciton motion is measured over Lumogen Red concentrations ranging from 1 × 10(-4) to 5 × 10(-2) M, and the results are compared to previous results for exciton diffusion in a solid polymer. Depending on the theoretical approach used to analyze the data, we find that the energy migration in the liquids is a factor of 2-3 faster than in the solid polymer, even after taking molecular translation into account. Measurements for a Lumogen Red concentration of 10 mM in the different host environments yield diffusion constants ranging from 2.2 to 3.1 nm(2)/ns in the liquids, as compared to 1.1-1.2 nm(2)/ns in solid poly(methyl methacrylate) (PMMA). The results in the liquids are in good agreement with theoretical predictions and numerical simulations of previous workers, while the results in solid PMMA are 2-3 times slower. This discrepancy is discussed in the context of the rapid energetic averaging present in the liquid environments but absent in the solid matrix, where unfavorable configurations and low energy trapping sites are frozen in by the static disorder.