Potential Adverse Effect of Ultrasound on the Electroretinogram of Retina and the Protective Role of Different Types of Antioxidants

Abstract

Background: Applications of ultrasound in medicine for therapeutic purposes have been an accepted and beneficial use of ultrasonic biological effects for many years but exposure to ultrasound can generate oxidative stress. Aim: The aim of the present study is to investigate the changes in the function of the retina due to ultrasound exposure and the protecting role of vitamin C and/or β-carotene by using electroretinogram (ERG). Materials and Methods: Newzealand albino rabbits of both sexes classified into five groups. Group (I) used as control group. The eyes of group (II) Insonificated with continuous ultrasound waves (1.5 W/cm 2 at 2.8 MHz) for 20, 40 and 60 minutes. Group (III) was insonificated with vitamin C instillation and group (IV) insonificated after β-carotene supplementation. Group (V) was insonificated after combination of the two treatments. Results: Statistically significant reduction (P˂ 0.05) in a-waves amplitude after insonification and exceeding with increase exposure time 20, 40 and 60 min was observed. The amplitudes of a-wave after treatment with topical and supplemented or both remained significantly larger compared with those exposure to US only but its latency lower than that found in insonified groups. In addition, the b-waves were found to follow the same behavior as a-wave. Conclusion: The study recommended considering oral β-carotene antioxidant in combination with vitamin C eye drops as a medical tool and personal protective in ultrasound equipment in provide safety.