Fascial expansions to the lids and orbital wall do not arise directly from the rectus muscles as "check ligaments." Instead, this fascia merges in the fornices with Tenon's capsule and subconjunctiva forming a tissue ring which encircles the globe. Incisions anterior to this fornix ring permit recession and resection under Tenon's capsule without disturbing fascial interrelations. Incisions into the fornices cause adnexal deformities. Tenon's capsule is easily elevated from the muscle sheaths which are separate structures continuous with anterior episcleral and intermuscular membranes. Integrity of the sheaths should be preserved. They are the primary source of fibroblasts for reattachment of tendons to the sclera. Fibroplasia from sheath defects causes adhesions.
Swan KC. Fascia in Relation to Extraocular Muscle Surgery. Arch Ophthalmol. 1970;83(2):134-140. doi:10.1001/archopht.1970.00990030136003