Experimental study of transient cochlear ischemia as a cause of sudden deafness

Table 1 Clinical features of idiopathic sudden sensorineural hearing loss and those of branch retinal vein occlusion

	ISSHL	Branch retinal vein occlusion
Annual incidence in Japan	35 000	30 000-50 000
Age preponderance (yr)	50-60	60
Sex difference	No	No
Incidence	Sudden	Sudden
Background disease	Unknown	Arteriosclerosis, diabetes mellitus
Involved site	Stria vascularis?	Retinal vein
Bilateral incidence	Rare	2%-4%
Recurrence	Rare	Rare
Spontaneous healing	30%-50%	30%-50%
Effects of steroid	Effective	Effective

ISSHL: Idiopathic sudden sensorineural hearing loss.