Lateral Tarsal Strip versus Tensor Fascia Lata Sling for Paralytic Ectropion: Comparison and Long-Term Outcomes

Background: Paralytic ectropion increases risk for corneal injury in facial palsy patients. Although a lateral tarsal strip (LTS) provides corneal coverage through superolateral lower eyelid pull, the unopposed lateral force may result in lateral displacement of the lower eyelid punctum and overall worsening asymmetry. A tensor fascia lata (TFL) lower eyelid sling may overcome some of these limitations. This study quantitatively compares scleral show, punctum deviation, lower marginal reflex distance, and periorbital symmetry between the two techniques. Methods: Retrospective review was performed on facial paralysis patients who underwent LTS or TFL sling surgery with no prior lower lid suspension procedures. Standardized preoperative and postoperative images in primary gaze position were used to measure scleral show and lower punctum deviation using ImageJ, and lower marginal reflex distance using Emotrics. Results: Of 449 facial paralysis patients, 79 met inclusion criteria. Fifty-seven underwent LTS surgery and 22 underwent TFL sling surgery. Compared with preoperatively, lower medial scleral show improved significantly with both LTS (10.9 mm²; P < 0.01) and TFL (14.7 mm²; P < 0.01). The LTS group showed significant worsening of horizontal and vertical lower punctum deviation when compared with the TFL group (both P < 0.01). The LTS group was unable to achieve periorbital symmetry between the healthy and paralytic eye across all parameters measured postoperatively (P < 0.01); and the TFL group achieved symmetry in medial scleral show, lateral scleral show, and lower punctum deviation. Conclusion: In patients with paralytic ectropion, TFL sling provides similar outcomes to LTS, with the added advantages of symmetry without lateralization or caudalization of the lower medial punctum.