Sector Area Index: A Novel Supporting Marker for Blepharoptosis Screening and Grading Publisher Pubmed



Mahmoudi T¹ ; Riaziesfahani H² ; Montazeriani Z³ ; Yaseri M⁴ ; Mehdipour Namdar Z⁵ ; Jamali M⁶ ; Rafizadeh SM^{7, 8} ; Khalili Pour E²
Source: International Ophthalmology Published:2023

Abstract

Purpose: To introduce a new supporting marker for discriminating different grades of ptosis called Sector Area Index (SAI) and a semi-automated technique to calculate it. Methods: In this cross-sectional comparative case series, a circle enclosing the intercanthal distance was automatically drawn after choosing two points as the medial and lateral canthus and manually selecting the palpebral fissure region. Finally, 15-degree apart sectors are applied to the enclosed circle. SAI was measured automatically by dividing the area of each 15-degree sector marked with the upper eyelid contour by the total area of the sector marked with the edge of the surrounding circle. SAI values and inter-eye SAI differences were compared between patients with different grades of ptosis as well as normal patients. Results: In the current study, 106 eyes were recruited (30, 25, 27, and 24 in the control, mild, moderate, and severe ptosis groups, respectively). Mean values of SAI in all sectors showed a decreasing trend from normal individuals toward patients with severe ptosis. The mean difference values of SAI between study eyes and fellow eyes in all four groups of patients showed a statistically significant difference (p < 0.05). In a pairwise comparison between groups, mean values of SAI in all nasal sectors from 15° to 60° showed a statistically significant difference between all groups (p < 0.05). Conclusion: The mean difference of SAI between study eyes and fellow eyes, including eyelid curvature, especially in 15°–60° and 120°–165° sectors, can demonstrate differentiating performance for detecting and discriminating varying grades of ptosis. © 2023, The Author(s), under exclusive licence to Springer Nature B.V.