AIM To establish whether the presence of a retinal break can be predicted either by the presence of a positive Shafer's sign (pigment granules in the anterior vitreous) or symptomatology in patients presenting with an acute posterior vitreous detachment (PVD). METHODS 200 eyes of 200 phakic patients with a symptomatic PVD of less than 1 month's duration underwent documentation of symptomatolo...

AEstivo-autumnal parasites, including the crescentic bodies, are always extracellular; that is, they are attached to the external surface of the red corpuscles. Crescentic bodies attach themselves to the red corpuscles just as the younger parasites do, by encircling, with their cytoplasm, mounds of hemoglobin substance. These hemoglobin mounds may be seen protruding through various portions of ...

Purpose. To compare morphologic changes in human trabecular meshwork (TM) after selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT). Design. Laboratory evaluation of ex vivo human eye TM after laser trabeculoplasty. Methods. Corneoscleral rims from human cadaver eyes were sectioned and treated with varying powers of either SLT or ALT. Specimens were examined using light ...

Fragments of fish melanophore cells can form and center aggregates of pigment granules by dynein-motor-driven transport along a self-organized radial array of microtubules (MTs). We present a quantitative model that describes pigment aggregation and MT-aster self-organization and the subsequent centering of both structures. The model is based on the observations that MTs are immobile and treadm...

Drosophila eye pigmentation defects have thus far been attributed to mutations in genes encoding enzymes required for biosynthesis of pigments and to ABC-type membrane transporters for pigments or their precursors. We report here that a defect in a gene encoding a putative coat adaptor protein leads to the eye color defect of garnet mutants. We first identified a human cDNA encoding delta-adapt...

Spontaneous tumors in urodele amphibians have been considered uncommon, and this resistance has sometimes been associated with the natural regenerative capacity of tissues in such species. This report describes spontaneous, nonpigmented, benign epitheliomas which were found in 44 of 1586 (2.8%) adult newts, Cynops pyrrhogaster, captured in central Japan. Both sexes were affected equally, usuall...

The fine structure of integumental erythrophores and the intracellular location of pteridine and carotenoid pigments in adult goldfish, Carassius auratus, were studied by means of cytochemistry, paper and thin-layer chromatography, ionophoresis, density-gradient centrifugal fractionation, and electron microscopy. The ultrastructure of erythrophores is characterized by large numbers of somewhat ...

While the ooplasmic components of centrifuged eggs of Arbacia punctulata do not stratify in homogeneous layers, we have obtained the following strata beginning with the centripetal end: lipid droplets, pronucleus, clear zone, mitochondria, yolk, and pigment. Whereas mitochondria may be found mingled with yolk bodies, we have never observed lipid droplets nor pigment bodies among any of the othe...

An unusual condition of the inferior retinal pigment epithelium (RPE) and neural retina has been observed in essentially all the large bullfrogs examined (Rana catesbeiana, 13 to 20 cm body length, supplied from the U.S. West Coast and Midwest). By ophthalmoscopy the inferior fundus exhibited numerous white spots and lines, which were found by light microscopy to be overlain by smaller black do...

The apposition eyes of two diurnal insects, Sarcophaga bullata (Diptera) and Anax junius (Odonata), have been examined with the electron microscope. In the latter case only the rhabdom is described. The rhabdom of the fly consists of a central matrix and seven rhabdomeres, one for each retinula cell. The rhabdomeres show an ordered internal structure built up of transverse tubes, hexagonal in c...