Analysis of Variation of Orbital Soft Tissue by a Novel Method in Magnetic Resonance Imaging

Accurate evaluation of the orbital soft tissue is essential when conducting surgery to remove excess lower eyelid fat. However, the eyelid puffiness decreases in the supine-position intraoperatively and when magnetic resonance imaging is performed preoperatively, compared with the standing/sitting-position in which patients are commonly examined. We investigated the orbital soft tissue difference between standing/sitting and supine positions. The study was conducted on six patients with an average age of 58.5 years. Anterior soft tissue and adipose tissue of eyeball axis, anterior adipose tissue in front of the infraorbital margin, total adipose tissue, and horizontal and vertical orbital positions were determined. Statistical examination by t test showed that soft tissue and adipose tissue, except for total adipose tissue, were significantly reduced in the supine-position compared with the standing/sitting-position. There was a significant difference in eye position only in the vertical direction. Anterior adipose tissue in front of the infraorbital margin, which is important during lower eyelid surgery, appeared 17.5% lower in the supine-position than in the standing/sitting-position. It is necessary to consider this postural discrepancy during the surgical management of lower eyelid fat.