RESUMO
This study was carried out to evaluate the effect of intratympanic steroid injection in treatment of induced sensorineural hearing loss in guinea pigs using scanning electron microscope. This work was conducted on 25 healthy guinea pigs with normal eardrum, preserved pinna reflex. The animals were divided into five groups: Control group, steroid group to evaluate the effect of intratympanic methylprednisolone acetate [MPA] injection by scanning electron microscope [SEM], noise group to demonstrate the scanning electron microscopic pictures immediately after the acoustic trauma, noise plus time group to evaluate effect of induced sensorineural hearing loss using micromotor drill against the body of incus by SEM and noise plus MPA group to evaluate the effect of MPA after 12 days from induced sensorineural hearing loss by SEM. The results showed that MPA had no damaging effect on inner ear structure, noise plus time group showed significant improvement but scar formation was noticed, while noise plus steroid group showed significant improvement with near normal pictures. It was concluded that MPA is a definite treatment of induced sensorineural hearing loss