Prostaglandin synthetic activity of neural retina and retinal pigment epithelium in chick retina was studied using arachidonic acid and prostaglandin H2 (intermediate prostaglandin endoperoxide) as substrates. To obtain sufficient enzyme activity in retinal pigment epithelium, cultured chick retinal pigment epithelial cells were used. Little arachidonic acid was converted into prostaglandins, a...

Choroidal osteomas are rare benign ossifying tumors that appear as irregular slightly elevated, yellow-white, juxtapapillary, choroidal mass with well-defined geographic borders, depigmentation of the overlying pigment epithelium; and with multiple small vascular networks on the tumor surface. Visual loss results from three mechanisms: Atrophy of the retinal pigment epithelium overlying a decal...

PURPOSE One of the most prominent changes that occurs in the retinal pigment epithelium during senescence is the progressive accumulation of the autofluorescent pigment lipofuscin. Experiments were conducted to evaluate the role of nonenzymatic oxidation of photoreceptor outer segments in retinal pigment epithelium lipofuscin formation. METHODS Albino Fischer rats were given intravitreal inje...

Retinal pigment epithelial dysfunction is believed to be the main cause of many debilitating retinal diseases of which age-related macular degeneration is the most common. In this disease, the retinal pigment epithelial dysfunction leads to photoreceptors damage causing severe vision loss. The retinal pigment epithelium and Bruch's membrane suffer cumulative damage over lifetime, which is thoug...

Pigment epithelial cell membrane potentials were measured in an in vitro frog retina-pigment epithelium-choroid preparation. Light stimuli hyperpolarized the apical membrane of the pigment epithelium. This hyperpolarization was the source of the c-wave of the electroretinogram. Light stimuli also decreased retinal extracellular potassium ion concentration, [K+]O, with the same time course as th...

Purpose To report the spectral domain optical coherence tomography (SD-OCT) features of a focal retinitis in an elderly male patient with bilateral syphilitic panuveitis. Observations In the left eye (LE), spectral domain SD-OCT images during the active period revealed hyperreflectivity extending through the full thickness of the retina with no individualization of the layers, except for the ...

The optic vesicle is a multipotential primordium of the retina, which becomes subdivided into the neural retina and retinal pigmented epithelium domains. Although the roles of several paracrine factors in patterning the optic vesicle have been studied extensively, little is known about cell-autonomous mechanisms that regulate coordinated cell morphogenesis and cytodifferentiation of the retinal...