No abstract

Summary Seeds of Ammi majus were fed to a group of ducklings which were exposed to sunlight. Acute symptoms of photosensitization developed after 2 to 3 days. One month later, after the acute phase had passed, mydriasis was seen in all the ducklings. In addition, ophthalmoscopic examination revealed dense pigment spots in the fundus. The control group of ducklings exposed to sunlight but not fed A. majus seeds showed no mydriasis or pigment spots. Zusammenfassung Augenveränderungen bei jungen Enten nach Fütterung von Ammi majus‐Samen Jungen Enten wurde Ammi majus‐Samen (Umbelliferenart) verabreicht unter gleichzeitiger Sonnenlicht‐Exposition der Versuchstiere. Nach 2–3 Tagen entwickelten sich Symptome der Photosensibilisierung. Ein Monat später, d. h. nach Abklingen der akuten Krankheitsphase trat bei alien Entchen eine Mydriasis auf, wobei sich im Augenfundus dichte Pigmentflecken entwickelten. Bei den Kontrolltieren (ohne Ammi majus‐Futter) fehlten sowohl die Mydriasis als auch die Pigmentflecken. Résumé Lesions oculaires chez des canetons alimentés avec des graines d'Ammi majus De jeunes canards ont reçu des graines d'Ammi majus (sorte d'ombellifère) et ont été en même temps exposes à la lumière solaire. Des symptômes de photosensibilisation se développèrent après 2–3 jours. Une mydriase est apparue chez tous les canetons un mois plus tard après la cessation de la phase aiguë de la maladie; d', épaisses taches de pigment se développèrent au fond de l'oeil. La mydriase comme les taches de pigment ne sont pas apparues chez les animaux de contrôle qui n'ont pas reçu d'Ammi majus. Resumen Modificaciones oftálmicas en patitos tras la alimentación con semilla de Ammi majus Se administró a patitos semillas de Ammi majus (umbelífera), exponiendo los animales al mismo tiempo a la luz solar. Tras 2–3 días se desarrollaron síntomas de fotosensibilización. Un mes más tarde, es decir, tras declinar la fase aguda de enfermedad, apareció una midriasis en todos los patitos, desarrollándose manchas pigmentarias densas en el fondo del ojo. En los animales testigos (que no recibieron pienso con Ammi majus) faltaban la midriasis y las manchas pigmentarias.

The acute and chronic symptoms seen in ducks following Ammi majus induced photosensitisation are described. The acute changes were inflammatory in nature whereas the chronic changes included severe deformities of the beak and footwebs, mydriasis and eccentric location of the pupil.

Geese and ducks were photosensitized by the ingestion of Ammi majus seeds, and exposure to sunlight. Mydriasis was a characteristic clinical feature of this syndrome in both species. Histologically the iris of the affected birds showed vacuolisation and varying degrees of atrophy of the muscle of the sphincter pupillae. The effect of pilocarpine and physostigmine on the normal and mydriatic eyes was studied. The possible mode of action of photosensitization and the significance of these findings in the light of the use of psoralens in human medicine is discussed.

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.