Objective To evaluate the clinical efficacy and safety of a modified conjoint fascial sheath （CFS） suspension

technique incorporating tri-plane dissection and double omega suture for the correction of severe blepharoptosis， and to establish a standardized surgical protocol. Methods In this retrospective cohort study，151 patients （177 eyes） with severe blepharoptosis treated between August 2023 and December 2024 were enrolled. Participants were divided into two groups， a conventional CFS suspension group （75 patients，85 eyes） and a modified CFS group （76 patients，92 eyes） that underwent tri-plane dissection combined with double omega suture technique. Surgical efficacy， eyelid retraction， lagophthalmos， complication rates， and patient satisfaction were compared between the two groups with a minimum follow-up of 6 months. Results The modified technique demonstrated significantly higher overall correction efficacy （96.74% vs 87.06%；χ² = 5.697，P=0.017）， lower complication rate （χ²=4.247，P=0.039）， and complete avoidance of conjunctival prolapse. Patient satisfaction was significantly higher in the modified group （93.42% vs 81.33%；χ² =5.008，P=0.0252）. Conclusion The modified CFS technique utilizing tri-plane dissection and double omega suture represents a safe， effective， and standardized approach for severe blepharoptosis correction. This innovative method enhances surgical outcomes through refined anatomical dissection， biomechanical optimization， and suture technique innovation， demonstrating significant clinical applicability.

Blepharoptosis, Conjoint fascial sheath, Tri-plane dissection, Double omega suture