Closure of previously patent laser iridotomies has been described as occurring early or late after the procedure. Early closure, occurring from minutes to hours after completion of the iridotomy, results from landsliding of iris pigment epithelium from above the site of the iridotomy or from large pigment particles floating in the posterior chamber, lodging in the iridotomy site, and occluding ...

Tyrian purple (also known as royal or imperial purple) is the oldest commercial pigment and still one of most expensive dyes, often associated with wardrobes clergy royalty. It a brominated derivative indigo, natural dye that has been used since 4000 BC. Moreover, just recently, therapeutic value indigoids for treatment several disorders was discovered. The manufacturing indigo derivatives by e...

Ripping of detached pigment epithelium appears to be a common sight-threatening complication of pigment epithelial detachments and occurs at the junction of the detachment and flat pigment epithelium. The characteristics of the detachment prior to the rip suggest that the tear occurs in pigment epithelium which is detached without its basement membrane. The tear is followed by retraction of the...

To directly test the hypothesis that only two pigment genes are expressed from the X-chromosome array, we examined expressed M and L pigment gene sequences from > 100 male eye donors. In this sample, there were eight men who expressed high levels of more than one L pigment gene in addition to M pigment genes. The fact that these eyes expressed both L and M pigment genes at significant levels su...

A B ST RACT Visual pigment bleaching desensitizes rod photoreceptors greatly in excess of that due to loss of quantum catch. Whether this phenomenon also occurs in cone photoreceptors was investigated for isolated salamander red-sensitive cones. In parallel experiments, (a) visual pigment depletion by steps of bleaching light was measured by microspectrophotometry, and (b) flash sensitivity was...

Visual pigment bleaching desensitizes rod photoreceptors greatly in excess of that due to loss of quantum catch. Whether this phenomenon also occurs in cone photoreceptors was investigated for isolated salamander red-sensitive cones. In parallel experiments, (a) visual pigment depletion by steps of bleaching light was measured by microspectrophotometry, and (b) flash sensitivity was measured by...

The distal pigment cells of Orconectes limosus contain two layers of large electron lucent vacuoles that are separated by layers of small right-angled platelets adjacent to the crystalline cones. The crystalline cones of the dioptric apparatus of this species have evaginations into the distal pigment cell cytoplasm. In photoreceptors of Orconectes limosus and Procambarus clarkii a dark pigment ...

SYNOPSIS. Integumental color changes and eye pigment movements in crustaceans are regulated by pigmentary-effector hormones. The identified hormones include: an octapeptide RPCH (red pigment-concentrating hormone) and several forms of octadecapeptide PDH (pigment-dispersing hormone: a-PDH, b-PDH). RPCH-related peptides (AKHs, adipokinetic hormones) and PDH-related peptides (PDFs, pigment-disper...