To compare associated lower lid retraction (LLR) with control fellow eyelid in patients with unilateral myogenic (MP) and aponeurotic (AP) ptosis before and after the ptosis repair and analyze factors affecting them.

Patients of >5 years old were included from June 2015 to April 2017. Other types of ptosis, associated strabismus and previous eyelid surgery were excluded. Eyelid examination, lower lid margin reflex distance (MRD2), and photography were performed before and at least 6 months after ptosis repair. MRDS of >0.5 as compared with the non-ptotic side was considered as LLR. MRD2 improvement of ≥0.5 mm at the last follow up was defined as success. All procedures (levator resection) were performed by or under supervision of one oculo-facial plastic surgeon.

Seventy-eight cases with MP (58) and AP (20) with mean age of 19.2 (MP) and 49.5 (AP) years and median follow up of 10 months were included. Mean MRD2 was 5.7 mm in MP and 5.5 in AP (P=0.9). Preoperative MRD2 was significantly (0.01) and negatively (r=-0.3) correlated with MRD1. It was 5 and 4.6 mm in the control eyelids of MP and AP, respectively (P=0.1). Success was observed in all of MP and 93.7% of AP group. Mean MRD2 was significantly (P=0.001) decreased from 5.5 to 5 in the MP and 5.6 to 4.9 mm in the AP group. No variable was significantly associated with mean post-operative MRD2 as well as its success.

LLR are commonly associated with both MP and AP in which the more severe the ptosis the higher the LLR. LLR was improved in all MP and majority of AP, postoperatively.