Related Experiment Video
Updated: Mar 29, 2026

Quantitative Assessment Protocol for Facial Soft Tissue Volumetric Changes with Stereophotogrammetry
Published on: December 9, 2025
Automated Ptosis Measurements From Facial Photographs
Zachary M Bodnar1, Michael Neimkin2, John B Holds1
1Department of Ophthalmology, Saint Louis University, St Louis, Missouri.
Importance:
Measurements of the margin reflex distances 1 and 2 are crucial for the surgical planning of ptosis repair and blepharoplasty. Facial photographs annotated with automated measurements of eyelid position could provide objective, accurate, and reproducible documentation of these features.
Objectives:
To describe a software algorithm for determining the margin reflex distances 1 and 2 from facial photographs and to evaluate its agreement with manual measurements of the margin reflex distances 1 and 2.
Design, Setting, And Participants:
Observational study at a single-surgeon oculoplastic private practice among 55 eyes of 28 adult volunteers. The study dates were July 30, 2014, to September 12, 2014. The dates of our analysis were October 12, 2014, to June 18, 2015.
Main Outcomes And Measures:
Agreement between manual and automated measurements of the margin reflex distances 1 and 2.
Results:
Among 55 eyes of 28 participants, automated margin reflex distance 1 measurements were strongly correlated with manual measurements (r = 0.97; 95% CI, r = 0.95 to r = 0.98; P < .001). The bias of automated margin reflex distance 1 measurements was 0.03 mm (95% CI, -0.06 to 0.12 mm), with 95% confidence limits of -0.66 and 0.71 mm. Automated margin reflex distance 2 measurements were strongly correlated with manual measurements (r = 0.96; 95% CI, r = 0.93 to r = 0.98; P < .001). The bias of automated margin reflex distance 2 measurements was 0.13 mm (95% CI, 0.03-0.22 mm), with 95% confidence limits of -0.54 and 0.80 mm.
Conclusions And Relevance:
Automated ptosis measurements produced by our software algorithm compare favorably with manually performed clinical measurements. An automated, photography-based system could provide an archival and highly reproducible means for obtaining the margin reflex distances 1 and 2 and other facial morphometric data.

