Epithelial ingrowth in descemet membrane endothelial keratoplasty associated with vitreous loss.

BACKGROUND: Epithelial ingrowth is a rare but potentially sight-threatening complication caused by the invasion of corneal or conjunctival epithelial cells into the eye during ocular surgeries. DMEK is emerging as a widely used surgery for endothelial keratoplasty with its improved safety profile. We describe a case of epithelial ingrowth in the graft-host interface after uneventful DMEK associated with vitreous prolapse in the anterior chamber. CASE PRESENTATION: An 81-year-old female with Fuchs endothelial dystrophy underwent DMEK for corneal decompensation following cataract surgery. During the DMEK procedure, vitreous prolapse was observed around the intraocular lens (IOL). Her early postoperative course was unremarkable, but a dense paracentral interface opacity was observed during the 3-month follow-up. The area of epithelial ingrowth was imaged with optical coherence tomography (OCT) as a uniform nodule with a discrete increase in interface hyperreflectivity. A low-energy YAG laser was applied to remove the opacity. She maintained good vision and clear cornea without reoccurrence after treatment. CONCLUSIONS: We propose that, in addition to the introduction of epithelial cells during surgery, vitreous retention in the anterior chamber may be a risk factor by providing a scaffold that potentially aggravates epithelial ingrowth in DMEK. Our case demonstrated that early YAG intervention may disrupt interface epithelial cell growth, and the transmitted laser energy may fragment the scaffold vitreous noninvasively.

Second report of a Nocardia beijingensis infection in the United States: nodular scleritis with in vitro imipenem resistance.

We describe the case of a 52-year-old woman with scleritis caused by an imipenem-resistant strain of Nocardia beijingensis. The patient presented with pain, redness, and nodules on the sclera of 8 weeks' duration. A Gram stain from a nodule on the superonasal aspect of the globe was initially negative. After empiric treatment for an autoimmune etiology, cytopathology confirmed filamentous bacteria. A presumptive diagnosis of Nocardia scleritis was made, and medical management was based on a literature review on treatments for Nocardia infections. Cultures returned confirming Nocardia beijingensis. Antibiotic sensitivity testing confirmed the correct initial management. The patient's scleritis resolved with a good visual outcome.

Herpes zoster stromal keratitis after varicella vaccine booster in a pediatric patient.

PURPOSE: In this study, the case of a healthy pediatric patient who presented with herpes zoster (HZ) stromal keratitis after vaccination with live attenuated varicella vaccine (Varivax) and subsequent booster is described. METHOD: This is a retrospective case review. RESULTS: A 6-year-old girl with no medical history presented with HZ ophthalmicus and stromal keratitis. She had received the original Varivax vaccine at 1 year of age and a booster 1 year before presentation. Topical prednisolone acetate was started with subsequent improvement in inflammation and visual acuity. However, the patient was unable to be completely tapered off the steroids because of reactivation. CONCLUSIONS: HZ ophthalmicus with stromal keratitis is a rare but potentially damaging manifestation of the varicella zoster virus in the pediatric population. Long-term data regarding reactivation rates in the post-vaccination era are still limited. Close follow-up is needed to ensure resolution of the infiltrates, and reactivation may require long-term steroid therapy.

Ocular manifestations of ANCA-associated vasculitis.

The antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides-Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome-can present with various ophthalmic manifestations. In a subset of patients, these findings may be the earliest indicators of systemic disease. Orbital and anterior segment findings are most common, whereas posterior segment complications such as retinal vasculitis and optic neuropathy occur much less frequently. This article describes the distinguishing features of associated ophthalmic disease, focusing on the manifestations clinicians are most likely to encounter and those with the most significant ocular morbidity. Although the ANCA-associated vasculitides require systemic workup and treatment, this article discusses diagnostic and therapeutic modalities often used concurrently for ophthalmic disease.

Ocular albinism with absent foveal pits but without nystagmus, photophobia, or severely reduced vision.

A 9-year-old Caucasian girl of northern European ancestry presented with findings suggestive of ocular albinism, although she maintains good visual acuity and lacks nystagmus and photophobia. DNA analysis revealed that the patient is a compound heterozygote for mutations in the tyrosinase gene, which is typically associated with overt, generalized oculocutaneous albinism and severe ocular symptoms. Her particular genotype confers no apparent cutaneous disease and only mild ocular features.

Direct interaction between BKCa potassium channel and microtubule-associated protein 1A.

The BKCa channel, a potassium channel that is allosterically activated by voltage and calcium, is expressed in both excitable and non-excitable cells. The channel plays an important role in regulating membrane excitability. The channel activity can be modulated by post-translational modifications such as phosphorylation. Recently, hippocampal BKCa channels were shown to be directly modulated by assembly/disassembly of the submembranous actin cytoskeleton. Here, we report that the BKCa channel physically interacts with the light chain of microtubule associated protein 1A (MAP1A). The light chain was isolated in a yeast two-hybrid screen of a human brain cDNA library. The specificity of the interaction was demonstrated in biochemical experiments utilizing GST fusion protein pulldown assays and reciprocal co-immunoprecipitations from rat brain. Furthermore, utilizing immunofluorescence, the BKCa channel and MAP1A co-localize in the Purkinje cell layer of the cerebellum. These studies identify a novel interaction between the C-terminal tail of the BKCa channel and the light chain of MAP1A, which enables channel association with and modulation by the cytoskeleton.

CTLA-4 regulates cell cycle progression during a primary immune response.

Engagement of CTLA-4 is critical for inhibiting T cell immune responses. Recent studies have shown that CTLA-4 plays a key role in regulating peripheral T cell tolerance. It has been suggested that one mechanism by which CTLA-4 performs this function is by regulating cell cycle progression. Here, we investigate in depth the role of CTLA-4 in regulating cell cycle progression in naive T cells by comparing the immune responses in the absence or presence of CTLA-4. In the absence of CLTA-4, T cells exhibit marked increases in T cell proliferation, IL-2 mRNA and protein secretion, and cells cycling in the S and G2-M phase. Analyses of cyclins, cyclin-dependent kinases, and cell cycle inhibitors involved in the transition from the G1 to S phase reveal that cell cycle progression is prolonged in the absence of CTLA-4. This is due to the early exit from the G1 phase, entry into the S phase, and prolonged S phase period. Re-expression of the cell cycle inhibitor p27(kip1) is delayed in the absence of CTLA-4. These studies demonstrate that the B7 : CTLA-4 pathway exerts its major effects on T cell immune responses via regulation of the cell cycle.