Covered or uncovered: A randomized control trial of Tegaderm versus no Tegaderm for ocular ultrasound

Studies on ocular point-of-care ultrasound vary on whether gel should be directly applied to the eye or on top of an adhesive membrane (i.e., Tegaderm™). However, there are currently no data regarding which approach has better image quality and the impact of patient preference. In this study, we sought to address this gap by assessing the difference in image quality and patient preference between Tegaderm™ versus no Tegaderm™ for ocular ultrasound in the emergency department.

Patients were randomized to have a Tegaderm™ placed on either their right or left eye. The other eye served as a comparator with no Tegaderm™. Ultrasound was performed on the right eye followed by the left eye in all instances. After performing each ultrasound, the sonographer asked the patient to rate their maximal discomfort from the ultrasound of that eye using a Likert scale (0 = no discomfort; 10 = severe discomfort). The sonographer then asked the patient which side (Tegaderm™ vs no Tegaderm™) they preferred. Finally, images were reviewed by an experienced ultrasound fellowship-trained sonographer blinded to allocation and rated from 1 to 5. Continuous data were analyzed using descriptive statistics with mean and standard deviation. A paired samples t-test was performed to assess for differences between groups. Categorical data were presented as frequency and percentage.

The mean image score was significantly worse with Tegaderm™ compared with no Tegaderm™ (mean difference: 0.94/5.00; 95% CI 0.79-1.08; p < 0.001). This was consistent in both the transverse and the sagittal plane subgroups. The percentage of acceptable images was also higher in the no Tegaderm™ group compared with the Tegaderm™ group (97.8% versus 82.8%). There was no statistically significant difference in patient discomfort with the Tegaderm™ versus no Tegaderm™ group. When asked to compare the two approaches, 54.4% of patients preferred Tegaderm™, 30.0% preferred no Tegaderm™, and 15.6% had no preference.

Tegaderm™ was associated with reduced image quality and no significant difference in patient discomfort when utilized for ocular ultrasound. This study suggests that ocular ultrasound may be better performed without the use of Tegaderm™. Future research should evaluate the impact of Tegaderm™ vs. no Tegaderm™ among more novice users.