These disturbances occur more often in the older age groups and are associated with hypertensive, arteriosclerotic, and diabetic changes in the circulatory systems. A brief discussion of the more common causes follows. Occlusion of the Central Retinal Artery Occlusion of the central retinal artery or one of its branches which supplies the macular region will result in almost immediate diminution or loss of visual acuity in the involved eye. In young adults the etiology is usually an embolus or spastic occlusion of the central retinal artery or one of its branches. Total occlusion of the central retinal artery or a branch can be diagnosed by observing the fundus and noting a pale area distal to the occlusion.
Treatment is aimed at vasodilatation and ocular massage.
In general the treatment that can be administered by the flight surgeon is very little. If the occlusion of a central retinal artery or its branch is total and it persists for more than five minutes, it is unlikely that the involved retina will recover. In older age groups the term amaurosis fugax has been used to describe fleeting vision. This condition results when moderate to severe arteriosclerotic narrowing of the interal carotid artery exists, causing lowered blood pressure to the ophthalmic artery. The patient describes gradual loss of visual acuity which persists for two to three minutes, then a gradual return of visual acuity.