Histology of the Retina and Choroid in Ducklings Photosensitized by Feeding Ammi majus Seeds

Abstract

Ducklings were photosensitized by the force-feeding of Ammi majus seeds for 5 days and exposure to sunlight. In birds sacrificed 2 weeks later, acute signs consisted of moderate vacuolization of ganglion cells. In birds sacrificed 3 ½ and 5 ½ months later, long-term effects of photosensitization included pigmentary retinopathy and hyperplasia of the retinal pigment epithelium. At the extreme periphery of the choroid, congestion and dilatation of the vessels, and transudation were observed. The probable mechanism whereby the photosensitization induces these changes in the retina and choroid of these ducklings is discussed.

Methoxsalen-Induced Ocular Lesions in Ducks

“…The manufacturers of the commercial prep aration of methoxsalen explain that a dichotomy of opinion exists as to its mode of action, one group of research workers stating that it has a specific effect on the melanocytes whereas another group writes that the action is inflammatory and the process of melanogenesis is secondary to this [Anon, 1968], Histological examinations of ducks photosensitized by A. majus seeds and exhibiting mydriasis and pigmentary retinopathy revealed vacuolization and atrophy of the muscle of the sphincter pupillae [Barishak et al, 1975]. Hyperplasia of the retinal pigment epithelium with congestion and dilatation of peripheral choroidal vessels was also noted [Barishak et al, 1976]. Parrish et al [1974] stated that no report had been published of any type of systemic toxicity after the use of oral methoxsalen, although he does not state if this refers to man or animals.…”

Ocular effects of treatment with various psoralen derivatives and ultraviolet‐A(UVA) radiation in HRA/Skh hairless mice

“…to experimental animals have been made by nu inerous investigators (Griffin 1959;Cloud et al 19(;0, 1961;Freeman 1966;Freeman & Troll 19fi9; Shlosberg et a]. 1974; Egyed et al , 1975Barishak et al 1975Barishak et al , 1976Singer et al 1976;Mikuni et al 1977;Witzel et al 1978;Jose & Yielding 1978;Clew 1979;Koch et al 1979;Jose et al 1982;Boutrous et al 1984). In contrast, PI' VA, administered chronically to rabbits at doses providing tolerable cutaneous effects, has also bec,n reported to cause no ocular damage (Parrish et .rl.…”