What the research shows
Repair helps sight as well as appearance. An American Academy of Ophthalmology review found that raising a low lid improves vision, side vision and daily activities, and listed the measurements that predict a benefit (Cahill 2011). Patients still reported the gain years after surgery (Vagefi 2025).
There are two standard operations. External levator advancement goes through an eyelid crease incision, often combined with an upper blepharoplasty. Müller muscle-conjunctival resection (MMCR) works from the inside of the lid and leaves no skin scar. In a randomized trial both raised the lid by the same amount, and MMCR scored slightly better on appearance (Saonanon 2018). Pooled comparisons found fewer over-corrections and fewer second operations after MMCR (Karam 2023, Ben Simon 2005), and MMCR also did well in severe droop (Sweeney 2020).
A second, smaller operation is common. In a large practice, about 1 in 11 had a revision, most often because a lid sat too low (Chou 2018). The rate was similar after levator advancement and higher when both eyes were operated on (McCulley 2003). Lid height keeps settling for about six weeks after surgery, so early judgments can mislead (Tucker 1999). In a national British audit, most patients were completely satisfied, and results were better for mild droop and for surgeons who did the operation often (Scoppettuolo 2008).
Raising one lid can let the other one fall. This linked movement, called Hering's effect, made surgery on both lids necessary more often after levator advancement than after MMCR (Nemet 2015).
Where surgeons disagree
- Which operation to choose. MMCR had better success over five years in one large comparison (Sweeney 2025), and posterior repair had fewer revisions in another (Chou 2018). Most eyelid specialists prefer the skin approach when they also remove upper lid skin (Aakalu 2011), and the earliest systematic review found no randomized comparison to settle it (Chang 2012).
- The eye-drop test before MMCR. Phenylephrine drops are used to preview the lift. Results were the same with and without the test, and it predicted the final height within a millimeter in only some patients (Saffari 2025).
What is new
- Patients who use prostaglandin glaucoma drops or steroid eye drops had more failed repairs, a point to raise at the consultation (Sweeney 2025, Dermarkarian 2021).
- Droop returned more often when the cause was congenital or muscular than when it was a stretched tendon (Cohen 2025).
- Oxymetazoline 0.1% eye drops raise the lid by about a millimeter within minutes of each daily dose (Bacharach 2021); side effects were mild and as common as with placebo drops (Wirta 2021). It is the only drug approved by the FDA for acquired ptosis in adults, and its long-term effect is unknown (Grob 2025).
What is still unknown
- The best sling material for a lid with a weak muscle: trials could not name one (Rosenberg 2019).
- How the drops compare with surgery over years: no long-term data exist (Grob 2025).
Key papers
- Tucker 1999: lid height settles over about six weeks after repair.
- McCulley 2003: set the expected reoperation rate after levator advancement.
- Ben Simon 2005: fewer second operations after MMCR than after levator advancement.
- Scoppettuolo 2008: national audit; frequent operators had better results.
- Cahill 2011: repair improves vision and daily function.
- Saonanon 2018: randomized trial; both operations raise the lid equally.
- Karam 2023: pooled comparison favoring MMCR for predictability.
- Sweeney 2025: glaucoma and steroid eye drops raise the risk of failure.
- Grob 2025: what eye drops can and cannot do for a drooping lid.