Universität zu Köln

Wang, Minghui ORCID: 0000-0003-3328-4647 (2026). Sleeping Position and Periocular Asymmetry: A three-dimensional Stereophotogrammetry Study. Diploma thesis, Universität zu Köln.

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Abstract

Previous studies have validated the accuracy of three-dimensional (3D) stereophotogrammetry in facial imaging. Although several studies have reported the associations between sleep posture and various periocular changes, the specific effects remain underexplored. In this study, we quantitatively assessed the effects of sleeping position preference on periocular asymmetry using 3D stereophotogrammetry. A total of 110 Caucasian volunteers were involved in this prospective study, who were divided into the Sleeping Side Preference (SSP) group and the Non-Sleeping Side Preference (Non-SSP) group, due to their different sleeping position behaviors. The VECTRA M3 3D Imaging System was used to obtain standardized 3D facial photographs. The Margin Reflex Ristance1(MRD 1), Margin Reflex Distance 2 (MRD 2), Palpebral Fissure Height (PFH), Palpebral Fissure Width (PFH), Upper Eyelid Crease Distance (UEC), Pupil-to-Eyebrow Distance (PE), Ocular Surface Area (OSA), and Whole Periocular Area (WPA) were measured by using VAM software. The asymmetry index was computed, and comparisons between the groups were performed to evaluate the impact of sleeping position on periocular asymmetry. Our results showed that 58 participants belonged to the SSP group and 52 were in the Non-SSP group. The groups did not differ significantly in terms of gender, average age, or average sleep duration. Within the SSP group, the preferred sleeping side revealed decreased MRD 1 (5.072±0.787 vs. 5.915±0.845, P<0.001), PFH (10.192±1.140 vs. 10.676±1.186, P<0.001), and OSA (2.307±0.637 vs. 2.383±0.626, P=0.045). There were no significant differences in MRD 2 (p = 0.520), PFW (p = 0.950), UEC (p = 0.107), PE (p = 0.413), and WPA (p = 0.437) between the preferred and non-preferred sleeping sides in the SSP group. Statistically significant differences were observed between the two groups in the asymmetry index of MRD 1 (P < 0.001), PFH (P =0.006), and OSA (P = 0.013). The comparisons between the two groups revealed no significant differences in the asymmetry index for MRD 2 (P = 0.719), PFW (P = 0.077), UEC (P = 0.658), PE (P = 0.165), or WPA (P = 0.257). No statistically significant association was found between the asymmetry index and average sleep duration. This was the first time that 3D stereophotography was used to quantitatively assess the impact of different sleeping positions on periocular asymmetry. Our results demonstrated that side sleeping was associated with increased upper eyelid asymmetry, primarily due to a reduced upper eyelid height. From a preventive perspective, the result may be informative for people to further increase awareness of the potential impact of long-term side sleeping and take corresponding preventive measures. For patients with periocular asymmetry, the result may be informative for them to slow down the progression of periocular asymmetry caused by sleeping position. In addition, the current study can also serve as a reference for ophthalmic surgeons in the process of preoperative counseling, in order to make a customized treatment plan in accordance with the patients' sleeping position habits, aiming at better surgical results as well as increasing patient satisfaction. Incorporating sleep posture evaluation into clinical consultations may represent a simple yet effective strategy for managing periocular asymmetry.

Item Type:	Thesis (Diploma thesis)
Creators:	Creators Email ORCID ORCID Put Code Wang, Minghui valerie_wmh@163.com https://orcid.org/0000-0003-3328-4647 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-804176
Date:	2026
Language:	English
Faculty:	Faculty of Medicine
Divisions:	Faculty of Medicine > Augenheilkunde > Klinik und Poliklinik für Allgemeine Augenheilkunde
Subjects:	Medical sciences Medicine
Uncontrolled Keywords:	Keywords Language periocular asymmetry English three-dimensional anthropometry English eyelid English
Date of oral exam:	29 April 2026
Referee:	Name Academic Title Heindl, Ludwig Universitätsprofessor Dr. med. Matthaei, Mario Professor Dr. med.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/80417