Frontalis muscle drive and the role of visual deprivation and lid proprioception
- UT Southwestern Ambulatory Services
The study design will be an investigational prospective experiment of healthy subjects. 20 healthy volunteers with no evidence of blepharoptosis will be recruited and baseline external photos will be obtained. This number was selected due to power calculations for a study between two independent groups with a dichotomous endpoint with an alpha error rate of 0.05 and power of 80%. Tests to determine ocular dominance will be performed. a dark contact lens to induce visual deprivation will be placed into the right eye for a short period of time until frontalis tone change can be detected. The contact lens will be removed and then a gold weight will be taped on to induce ptosis. again, frontalis tone will be assessed. This process will then be repeated with the left eye. Change in brow position will be analyzed from baseline for each intervention (contact lens versus gold weight) and investigated for statistical significance. Significant changes in brow position with a specific intervention would be suggestive of that mechanism contributing to compensatory frontalis tone.
Inclusion criteria will include:
* Ability to give informed consent
* Males or female of any ethnicity and race who are 18 to 65 years of age
* No evidence of blepharoptosis or previous eyelid surgery or significant facial trauma