Quantitative Assessment Of Lacrimal Groove Deformity In Chinese Using Three-dimensional Photogrammetry And Its Clinical Application

ObjectiveThe tear trough deformity is such a crucial aesthetic problem that it has become one of the most discussed landmarks in facial rejuvenation.The anatomical basis of this landmark is complicated,involving an underlying retaining ligament and several age-related changes of the midface.Lower blepharoplasty has become a popular approach for tear trough treatment.Nevertheless,reliable assessment tools for evaluating the severity and treatment outcome of tear troughs are still limited.The present study aimed to develop and validate a novel measurement scale for tear trough deformity in Chinese population through three-dimensional(3D)photogrammetry.In the second part,clinical cases of lower blepharoplasty with orbital fat repositioning for tear trough rejuvenation were reported.MethodsFrom January to April 2021,healthy Chinese adults around Peking Union Medical College Hospital were randomly recruited for this prospective,cross-sectional study.A 3D face photo of each subject was captured using VECTRA H1 handheld camera.Six pairs of anthropometric landmarks were defined and identified for the measurement of tear trough parameters.Eight pairs of linear measurements were computed from the coordinates.The reproducibility of landmark identification was determined by intra-observer reliability.The subjects were divided into four groups according to Barton's grading system.Intergroup comparisons of the measurements were performed to investigate the effectiveness of this novel assessment tool.Statistical significance was defined as P<0.05.ResultsPart I:A total of 117 subjects were enrolled,including 106 females and 11 males,aged 39.89±15.37(mean±SD)years.The severity of the tear trough showed positive correlation with age(p=0.629,P<0.001),but seems not to be significantly related with BMI(p=0.160,P=0.145)or gender(P=0.280).86.4%of subjects aged 21-40 years possessed Grade I or II tear trough deformity.Intraclass correlation coefficients of the linear parameters were no less than 0.80 except for the vertical distance between the lower eyelid margin and the tear trough.As the grade rose,the horizontal distance between the lateral end of the tear trough and medial canthus increased significantly(P<0.001);the vertical distance from mid-pupil to lower eyelid margin gradually decreased(P=0.009),indicating an elevation of lower eyelid margin.The sagittal vector from tear trough point towards eye bag point also showed a grading-related increase(P=0.001).Part ?:A total of 102 patients with bilateral tear trough deformity underwent lower blepharoplasty with orbital fat repositioning.Postoperative improvements were significant and long-lasting.All patients reported a high level of satisfaction.Regarding postoperative complications,2 eyes required revision because of insufficient lipectomy,and numbness of the infraorbital skin occurred in 3 eyes.ConclusionThis study demonstrated a novel method for quantitatively assessing the severity of tear trough deformity using 3D photography and proved it to be valid and reliable.Three linear measurements of eight showed good value of clinical application.The anthropometric data collected could help with facial rejuvenation planning and outcome assessment.A review of clinical cases indicated that fat repositioning is a safe and effective approach for the correction of tear trough deformity.