Retinal recovery from exposure to light.
About: This article is published in American Journal of Ophthalmology.The article was published on 1970-08-01. It has received 130 citations till now. The article focuses on the topics: Retinal.
Citations
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TL;DR: The evidence that solar radiation is responsible for some of the deteriorative changes that lead to age-related macular degeneration is examined in this review.
398 citations
TL;DR: The findings indicate that the photoreceptor rescue activity of bFGF is not restricted to inherited retinal dystrophy in the rat, and that light damage is an excellent model for studying the cellular site(s), kinetics, and molecular mechanisms of both the normal function ofbFGF and its survival- promoting activity.
Abstract: Injection of basic fibroblast growth factor (bFGF) into the eye, intravitreally or subretinally, delays photoreceptor degeneration in inherited retinal dystrophy in the rat, as does local injury to the retina (Faktorovich et al., 1990). To determine whether this heparin- binding peptide or local injury is effective in any other form of photoreceptor degeneration, we examined their protective roles in light damage. Albino rats of the F344 strain were exposed to 1 or 2 weeks of constant fluorescent light (115–200 footcandles), either with or without 1 microliter of bFGF solution (1150 ng/microliters in PBS) injected intravitreally or subretinally 2 d before the start of light exposure. Uninjected and intravitreally PBS-injected controls showed the loss of a majority of photoreceptor nuclei and the loss of most inner and outer segments after 1 week of light exposure, while intravitreal injection of bFGF resulted in significant photoreceptor rescue. The outer nuclear layer in bFGF-injected eyes was two to three times thicker than in controls, and the inner and outer segments showed a much greater degree of integrity. Following recovery in cyclic light for 10 d after 1 week of constant light exposure, bFGF-injected eyes showed much greater regeneration of photoreceptor inner and outer segments than did the controls. bFGF also increased the incidence of presumptive macrophages, located predominantly in the inner retina, but the evidence suggests they are not directly involved in photoreceptor rescue. Subretinal injection of bFGF resulted in photoreceptor rescue throughout most of the superior hemisphere in which the injection was made, with rescue extending into the inferior hemisphere in many of the eyes. Remarkably, the insertion of a dry needle or injection of PBS into the subretinal space also resulted in widespread photoreceptor rescue, extending through 70% or more of the superior hemisphere, and sometimes into the inferior hemispheres. This implicates the release and widespread diffusion of some endogenous survival-promoting factor from the site of injury in the retina. Our findings indicate that the photoreceptor rescue activity of bFGF is not restricted to inherited retinal dystrophy in the rat, and that light damage is an excellent model for studying the cellular site(s), kinetics, and molecular mechanisms of both the normal function of bFGF and its survival- promoting activity. Moreover, the injury-related rescue suggests that survival-promoting factors are readily available to provide a protective role in case of injury to the retina, presumably comparable to those that mediate the “conditioning lesion” effect in other neuronal systems.
369 citations
Cites background from "Retinal recovery from exposure to l..."
...…qf photoreceptors in cyclic light following light damage Since rod outer segments can regenerate following sublethal light damage to photoreceptors (Kuwabara, 1970; Lanum, 1978; McKechnie and Foulds, 1980; Wyse, 1980), we examined retinas of rats that were allowed to recover for 10 d in cyclic…...
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...Since rod outer segments can regenerate following sublethal light damage to photoreceptors (Kuwabara, 1970; Lanum, 1978; McKechnie and Foulds, 1980; Wyse, 1980), we examined retinas of rats that were allowed to recover for 10 d in cyclic light following either 1 or 2 weeks of constant light, either with or without intravitreal bFGF injection....
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359 citations
TL;DR: This work has suggested that blue light may play a role in the pathogenesis of age-related macular degeneration, and laboratory studies have suggested that photochemical damage includes oxidative events.
350 citations
TL;DR: It is suggested that retinal damage may be produced by such common light sources as room lighting, phototherapy techniques, ophthalmoscopes and fundus cameras.
249 citations
References
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TL;DR: The disposal phase of the retinal rod outer segment renewal process has been studied by radioautography in adult frogs injected with tritiated amino acids to identify inclusions within the pigment epithelium by virtue of their content of radioactivity.
Abstract: The disposal phase of the retinal rod outer segment renewal process has been studied by radioautography in adult frogs injected with tritiated amino acids. Shortly after injection, newly formed radioactive protein is incorporated into disc membranes which are assembled at the base of the rod outer segment. During the following 2 months, these labeled discs are progressively displaced along the outer segment owing to the repeated formation of newer discs. When the labeled membranes reach the end of the outer segment, they are detached from it. They subsequently may be identified in inclusion bodies within the pigment epithelium by virtue of their content of radioactivity. These inclusions have been termed phagosomes. Disc membrane formation is a continuous process, but the detachment of groups of discs occurs intermittently. The detached outer segment fragments become deformed, compacted, undergo chemical changes, and are displaced within the pigment epithelium. Ultimately, the material contained in the phagosomes is eliminated from the cell. In this manner the pigment epithelium participates actively in the disposal phase of the rod outer segment renewal process.
1,180 citations
Journal Article•
TL;DR: The retina of laboratory rats is affected irreversibly by intense light applied for less than 1 hour or for up to 2 days depending upon experimental conditions, and the action spectrum of the daviaging effect approximated that of visual excitation as measured by the ERG.
Abstract: The retina of laboratory rats is affected irreversibly by intense light applied for less than 1 hour or for up to 2 days depending upon experimental conditions. Exposure of unanesthetized and unrestrained animals was in chambers surrounded by a green filter and circular fluorescent lamps of a nominal brightness of 2,040 footlamberts. Eyes of anesthetized animals were exposed diffusely to either the light from a 100 to. zirconium arc passing through filters or monochromatic light of various icavelengths. Irreversible reduction in ERG amplitudes and degeneration of visual cells and pigment epithelium indicated the severity of the light damage. The effect was very dependent upon the body (eye) temperature during exposure. Hyperthermia greatly accelerated and intensified the damaging action of light and for this reason most experiments reported in this paper were performed at a high body temperature. At a body temperature around 104° F. severe damage teas produced with exposures to 5 to 10 iiw per square centimeter retina for 1 hour. The minimal damaging dose at a high temperature was estimated to be about 1 ixw per square centimeter. The action spectrum~of the daviaging effect approximated that of visual excitation as measured by the ERG. Hooded (pigmented) animals were no more affected than albinos of different strains. Recovery in the dark from a just subliminally damaging dose of light at a high body temperature required about 24 hours and was preceded by a period of time during ichich the retina was "sensitized" to an additional dose. During or following exposure to light at a high body temperature visual cell and pigmentepithelial_damage developedTabout simultaneouslu and was first indicated bit pyknosis Trncl cell swelling followed rapidly by the dissolution of nuclei and cytoplasm. The crucial reaction in producing the damage is considered a "dark-reaction" initiated by light of an -inte7isiiTj_ which bleaches measurably rhodopsin. Hypotheses on the reaction sequence which 'leads to damage are briefly discussed.
1,121 citations
TL;DR: The renewal of protein in retinal rods and cones has been analyzed by quantitative electron microscope radioautography in adult frogs injected with a mixture of radioactive amino acids and appears to involve the utilization of protein formed in the ergastoplasm of the myoid.
Abstract: The renewal of protein in retinal rods and cones has been analyzed by quantitative electron microscope radioautography in adult frogs injected with a mixture of radioactive amino acids. Protein synthesis occurs predominantly in the ergastoplasm, localized in the myoid region of the photoreceptor cells. Much of the newly formed protein next flows through the Golgi complex. In rods, a large proportion of the protein then moves past the mitochondria of the ellipsoid segment, passes through the connecting cilium into the outer segment, and is there assembled into membranous discs at the base of that structure. Discs are formed at the rate of 36 per day in red rods and 25 per day in green rods at 22.5° C ambient temperature. In cones, a small proportion of the protein is similarly displaced to the outer segment. However, no new discs are formed. Instead, the protein becomes diffusely distributed throughout the cone outer segment. Low levels of radioactivity have been detected, shortly after injection, in the mitochondria, nucleus, and synaptic bodies of rods and cones. Nevertheless, in these organelles, the renewal process also appears to involve the utilization of protein formed in the ergastoplasm of the myoid.
395 citations
TL;DR: Rat retinas were studied during the first three postnatal weeks, and it was at this time the first response was recorded on the electroretinogram.
Abstract: Rat retinas were studied during the first three postnatal weeks. Outer segments began developing during the fifth postnatal day and were in close association with pigment epithelium. Developing photoreceptor lamellae were seen to be continuous with smooth endoplasmic reticulum. The outer plexiform layer began to form on the fifth day by the lateral extension of the horizontal cell processes. On the 12th day synapses were formed in the inner plexiform layer, and it was at this time the first response was recorded on the electroretinogram.
349 citations
TL;DR: Upon exposure to relatively cold light at a brightness of approximately 750 foot-candles (ft-c), photoreceptic outer segments of the albino rat demonstrate remarkable membranous changes.
Abstract: SEVERE damage to the retina by exposure to light has recently been demonstrated by Noell 1,2 and by us. 3,4 To establish the pathogenetic mechanisms, a series of electron microscopic studies of the retinas which had been exposed to lights under several conditions has been in progress in this laboratory. Depending on the duration of the light exposure and the nature of the light sources, the retinas show damage varying all the way from total degeneration of the whole retina to minimal changes in the photoreceptors. Upon exposure to relatively cold light at a brightness of approximately 750 foot-candles (ft-c), photoreceptic outer segments of the albino rat demonstrate remarkable membranous changes. The purpose of this paper is to describe such changes in the photoreceptic cells and to discuss the mechanisms of the damage. Materials and Methods Albino rats were mainly used in the experiment. Ordinary wire mesh animal cages
311 citations