Author Block: Mohammad Karam¹,  Abdulmalik Alsaif ², Ahmad Abul³, Ali Alkhabbaz⁴, Abdulaziz Alotaibi¹, Eiman Shareef¹, Raed Behbehani¹.  ¹AlBahar Ophthalmology Center, Ibn Sina Hospital, Ministry of Health, State of Kuwait, ²Walsall Healthcare NHS Trust, West Midlands, UK, ³School of Medicine, University of Leeds, Leeds, UK, ⁴Faculty of Medicine, Kuwait University, State of Kuwait.

Author Disclosure Block: Author Disclosure Block:   M. Karam:  None.  A. Alsaif:  None.  A. Abul:  None.  A. Alkhabbaz:  None.  A. Alotaibi:  None.  E. Shareef:  None.  R. Behbehani:  None.

Abstract Title: Muller's Muscle Conjunctival Resection versus External Levator Advancement for Ptosis Repair: Systematic Review and Meta-Analysis

Abstract Body: Purpose:  To compare the outcome of Muller's muscle conjunctival resection (MMCR) versus external levator advancement (ELA) in patients undergoing ptosis surgery.  Study Design:  Systematic Review and Meta-Analysis.  Methods:  A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, and a search of electronic information was conducted to identify all comparative studies of MMCR versus ELA in ptosis repair. The primary outcome measures were the postoperative marginal reflex distance (MRD1), ptosis under-correction, and over-correction, as well as re-operation rate. Secondary outcome measures included cosmetic appearance, complications, operative time and learning curve. Fixed-effect modeling was used for the analysis.  Results:  Seven studies that enrolled 1038 eyelids were identified in the literature. There was no statistically significant difference between the MMCR and ELA groups in post-operative MRD1 (Mean Difference [MD] = 0.13, P = 0.28) and the rate of under-correction odds ratio [OR] = 0.49, P = 0.14). However, ELA had a significantly higher rate of overcorrection (OR = 0.17, P = 0.04) and reoperations (OR = 0.26, P = 0.0001) compared to MMCR. For secondary outcomes, MMCR had an improved cosmetic appearance, lower total number of complications and shorter operation time (MD = -10.96, P <0.00001). Finally, there was no significant difference in the learning curves between the two techniques.  Conclusions:  Both MMCR and ELA are effective techniques for the surgical correction of ptosis; however, MMCR surgery is a more predictable and robust technique compared to, ELA with lower rates of overcorrection and re-operation.