Original ArticlesImpact of Canthal Height on Horizontal Upper Eyelid Peak Position A Guide for Blepharoptosis SurgeryKitaguchi, Yoshiyuki MD, PhD*,†; Takahashi, Yasuhiro MD, PhD‡; Kakizaki, Hirohiko MD, PhD‡; Gomi, Fumi MD, PhD†,§; Nishida, Kohji MD, PhD*Author Information *Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita †Department of Ophthalmology, Sumitomo Hospital, Osaka ‡Department of Oculoplastic, Orbital and Lacrimal Surgery, Aichi Medical University Hospital, Nagakute §Department of Ophthalmology, Hyogo College of Medicine, Nishinomiya, Japan. Address correspondence and reprint requests to Yoshiyuki Kitaguchi, MD, PhD, Department of Ophthalmology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; E-mail: firstname.lastname@example.org Received 22 October, 2018 Accepted 17 July, 2019 The authors report no conflicts of interest. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.jcraniofacialsurgery.com). Journal of Craniofacial Surgery: January/February 2020 - Volume 31 - Issue 1 - p 138-141 doi: 10.1097/SCS.0000000000006032 Buy SDC Metrics Abstract This study was aimed at examining the relationship between the horizontal upper eyelid peak position (Δpeak-pupil) and the difference between the medial and lateral canthal heights (Δcanthi) in Japanese individuals. Images of the left eyelid of 71 participants without eyelid disease were acquired with a camera with a slit-lamp microscope. Multivariate linear regression analysis was performed to determine the influence of age, sex, distance from the pupil center to the upper eyelid margin (margin reflex distance-1), Δcanthi, and palpebral fissure width on Δpeak-pupil. In addition, Δpeak-pupil distribution in participants with Δcanthi <3 (Group A), 3 to 6 (Group B), and >6 mm (Group C) was calculated as the average±2x the standard deviation. The mean Δpeak-pupil was 1.12 ± 1.29 mm (range: −1.44 to 6.12) and the mean Δcanthi was 4.50 ± 1.71 mm (1.02–7.96). Δcanthi was a significant determinant factor of Δpeak-pupil (P < 0.0001), whereas age (P = 0.62), sex (P = 0.88), margin reflex distance-1 (P = 0.29), and the horizontal palpebral fissure width (P = 0.65) were not related to Δpeak-pupil. The normal Δpeak-pupil ranges were −1.47 to 1.52, −0.95 to 3.22, and −0.84 to 4.73 mm in Groups A, B, and C, respectively. There was a statistically significant difference between the Group A and B ranges and between the Group A and C ranges (Kruskal–Wallis test, P < 0.01). It was concluded that the normal eyelid peak position differs according to medial-to-lateral canthal positional difference. This finding may help intraoperative determination of the upper eyelid peak position in blepharoptosis surgery. © 2020 by Mutaz B. Habal, MD.