1 The lower lid tarsus is 3.5 to 4 mm. Lockwood’s ligament is about 20 mm back from the inferior tarsal border.

2 Lockwood’s ligament helps prevent descension of the globe with loss of other inferior bony support. Think of it as a hammock.

3 If this ligament is caught in a blowout fracture, hypoglobus (lowered globe) will result.

4 The inferior rectus and inferior oblique muscles are intimate with this structure. Some strabismus surgery naturally may separate these muscles from their fascial associations with this ligament.

1 The upper lid tarsal plate is 9 to 11 mm, and Whitnall’s ligament is 25 mm above that. The levator aponeurosis travels for 30 mm from the tarsal plate, and the levator muscle starts at 40 to 45 mm from the tarsus.

2 In cases of severe congenital ptosis, some surgeons will cut this ligament as part of a large levator resection to allow the levator muscle to come forward.

3 Whitnall’s ligament actually has a superior component and an inferior component. The superior component, visible on the levator surface, is attached medially to fascia around the trochlea of the superior oblique. Laterally, the ligament splits the lacrimal gland (it helps support the gland and is adherent to its stroma) and attaches to the orbital wall laterally.

4 Whitnall’s ligament in some cases may be a taut band; in other cases, a flimsy one. The taut ligaments can help repair the severe ptosis cases, as the ligament may assist in eyelid suspension as opposed to the frontalis sling.