The lateral check ligament is the fibrous lateral extension of the fascial sheath of the lateral rectus muscle, condensing and attaching to Whitnall tubercle on the inner surface of the zygomatic bone at the lateral orbital wall. It is broader and stronger than the medial check ligament, forming a thick triangular band that limits excessive adduction and contributes to lateral canthal support of the lower eyelid.
Limits extreme adduction of the globe, supports the lateral canthus of the eyelid, and contributes to the lateral orbital retinaculum that maintains lateral canthal position.
The lateral check ligament is an important landmark in lateral orbital surgery and in lower eyelid reconstruction procedures. It attaches directly to Whitnall tubercle, the same landmark targeted by the lateral canthal tendon and lateral retinaculum during lower eyelid tightening (lateral tarsal strip procedure) and facelift lateral canthopexy. In thyroid eye disease (Graves orbitopathy), the lateral rectus and its check ligament may be thickened and fibrotic, contributing to restricted abduction.
Attenuation of the lateral check ligament complex contributes to lateral canthal malposition and lower eyelid laxity with ectropion in the elderly, corrected by lateral tarsal strip and canthopexy procedures that reattach the lateral check ligament complex to Whitnall tubercle.
Fibrosis and thickening of the lateral rectus and its check ligament in Graves orbitopathy produces restricted abduction and diplopia on lateral gaze, treated with orbital decompression and strabismus surgery with careful check ligament release.
