Last ocular muscle to be involved in Graves' disease-
*Order of involvement (Mnemonic : IM SLO) :- Inferior rectus > medial rectus > superior rectus > Lateral rectus > obliques. Ref: Head & Neck Surgery 2nd/e p.1513
Inferior rectus
Lateral rectus
Superior rectus
Inferior oblique
Diseases of orbit, Lids and lacrimal apparatus