Intercellular Junctions of the Ciliary Epithelium in Anterior Uveitis

The intercellular junctions of the anterior ciliary and iridial epithelia of the inflamed rabbit eye were examined by use of an ultrastructural tracer, conventional electron microscopy, and the freeze-fracture technique. In normal control eyes, intravascularly injected horseradish peroxidase was prevented from entering the posterior chamber by the zonulae occludentes of the nonpigmented ciliary epithelium. In freeze-fracture studies these junctions appeared as a series of 5-12 branching and anastomosing strands on the P-fracture face, which were complemented by a network of shallow grooves with discontinuous rows of particles at their bases on the E-fracture face. Gap junctions were abundant, particularly between the apical surfaces of the pigmented and nonpigmented layers where they were accompanied by discontinuous tight junctional strands. In eyes inflamed by intravitreal injection of E. coli 055:B55 endotoxin, peroxidase leaked into the posterior chamber primarily from the crests of anterior ciliary and iridial processes. Freeze-fracture electron microscopy of these same areas demonstrated primarily a simplification in junctional complexity and reduction in the number of occluding strands. Severe junctional disorganization and complete junctional fragmentation were rarely seen. A profound reduction in the complement of gap junctions was observed particularly between the apical surfaces of the pigmented and nonpigmented layers. The possible functional significance of the observed changes is discussed. Invest Ophthalmol Vis Sci 28:320-329, 198

Loss of AND-34/BCAR3 Expression in Mice Results in Rupture of the Adult Lens

PURPOSE. AND-34/BCAR3 (Breast Cancer Anti-Estrogen Resistance 3) associates with the focal adhesion adaptor protein, p130CAS/BCAR1. Expression of AND-34 regulates epithelial cell growth pattern, motility, and growth factor dependence. We sought to establish the effects of the loss of AND-34 expression in a mammalian organism. METHODS. AND-34−/− mice were generated by homologous recombination. Histopathology, in situ hybridization, and western blotting were performed on murine tissues. RESULTS. Western analyses confirmed total loss of expression in AND-34−/− splenic lymphocytes. Mice lacking AND-34 are fertile and have normal longevity. While AND-34 is widely expressed in wild type mice, histologic analysis of multiple organs in AND-34−/− mice is unremarkable and analyses of lymphocyte development show no overt changes. A small percentage of AND-34−/− mice show distinctive small white eye lesions resulting from the migration of ruptured cortical lens tissue into the anterior chamber. Following initial vacuolization and liquefaction of the lens cortex first observed at postnatal day three, posterior lens rupture occurs in all AND-34−/− mice, beginning as early as three weeks and seen in all mice at three months. Western blot analysis and in situ hybridization confirmed the presence of AND-34 RNA and protein in lens epithelial cells, particularly at the lens equator. Prior data link AND-34 expression to the activation of Akt signaling. While Akt Ser 473 phosphorylation was readily detectable in AND-34+/+ lens epithelial cells, it was markedly reduced in the AND-34−/− lens epithelium. Basal levels of p130Cas phosphorylation were higher in AND-34+/+ than in AND-34−/− lens epithelium. CONCLUSIONS. These results demonstrate the loss of AND-34 dysregulates focal adhesion complex signaling in lens epithelial cells and suggest that AND-34-mediated signaling is required for maintenance of the structural integrity of the adult ocular lens.National Institutes of Health (RO1 CA114094); Logica Foundatio

Contrast-Enhanced Magnetic Resonance Imaging Confirmation of an Anterior Protein Pathway in Normal Rabbit Eyes

Purpose: Contrast-enhanced proton magnetic resonance imaging ( 1H MRI) has been used as a quantitative, noninvasive method to corroborate a pathway for the diffusion of plasma-derived protein into the aqueous humor in the normal rabbit eye. Methods. T1-weighted magnetic resonance images were produced over 1- to 3-hour periods after the intravenous injection of gadolinium diethylenetriamine-pentaacetic acid. Results. Analysis of the images yielded the time dependence of signal enhancements within the areas of interest. The ciliary body showed an immediate sharp increase, followed by a gradual decrease in signal enhancement with time. Although a gradual increase in signal enhancement was found in the anterior chamber, no significant change occurred in the posterior chamber. A similar MRI experiment with an owl monkey produced parallel, though smaller, signal enhancements in the ciliary body and anterior chamber. Again, however, no significant change was found in the posterior chamber. Conclusions. These results support and extend those of recent fluorophotometric, tracer-localization, and modeling studies demonstrating that in the normal rabbit and monkey eye, plasma-derived proteins bypass the posterior chamber, entering the anterior chamber directly via the iris root

Freddo, “Cytokeratin expression in normal human bulbar conjunctiva obtained by impression cytology

Purpose. To document the cytokeratin expression patterns in the normal human conjunctival epithelium obtained directly from patients using impression cytology. Methods. Impression cytology specimens were obtained from normal volunteers using pure nitrocellulose membranes rather than cellulose acetate. The 31 volunteers of both sexes ranged in age from 18 to 79 years. Impression cytology specimens were analyzed for individual cytokeratins by either immunocytochemistry or electrophoresis with immunoblotting using a defined panel of monoclonal antibodies. Results. Using the corroborative mediods of immunocytochemistry and electrophoresis with immunoblotting, cytokeratins characteristic of nonkeratinized, stratified (K4 and K13), simple (K8 and K19), and glandular epidielia (K7) were present in the superficial layer(s) of normal human conjunctiva. Cytokeratins typical of keratinized epithelia (Kl, K2, and K10) and the keratinization-related proteins filaggrin and involucrin were not expressed in normal conjunctival epithelium. Conclusions. The normal human conjunctiva demonstrates a unique cytokeratin expression pattern containing cytokeratins characteristic of nonkeratinized, stratified epithelia, as well as others more typical of a simple differentiation pattern, a glandular differentiation pattern, or both. These findings provide a foundation for examining changes in the cytokeratin expression pattern in diseased human conjunctival epithelium using impression cytology

A review of acquired blepharoptosis: prevalence, diagnosis, and current treatment options

Blepharoptosis (ptosis) is among the most common disorders of the upper eyelid encountered in both optometric and ophthalmic practice. The unilateral or bilateral drooping of the upper eyelid that characterises ptosis can affect appearance and impair visual function, both of which can negatively impact quality of life. While there are several known forms of congenital ptosis, acquired ptosis (appearing later in life, due to a variety of causes) is the predominant form of the condition. This review summarises the prevalence, causes, identification, differential diagnosis, and treatment of acquired ptosis. Particular attention is paid to the differential diagnosis of acquired ptosis and emerging treatment options, including surgical and pharmacologic approaches