PurposeTo determine the predictability of a new algorithm for determining the amount of tissue resection for conjunctival Müllerectomy with or without tarsectomy blepharoptosis repair.MethodsConsecutive case series of all patients undergoing conjunctival Müllerectomy with or without tarsectomy ptosis repair from October 1999 to September 2001. Each patient underwent excision according to a new algorithm for determining the amount of tissue excision. The amount resected was determined by the following formula: 9 mm of conjunctiva and Müller muscle +xmm of tarsus, wherex= distance of undercorrection after phenylephrine testing.ResultsSixty-eight consecutive patients underwent 70 cases of conjunctival Müllerectomy with or without tarsectomy ptosis repair on 117 eyelids, using a new algorithm for tissue excision. Forty-seven cases were bilateral and 23 were unilateral. Postoperative symmetry was found in 58 of 67 patients (87%) after 1 surgery. Patient satisfaction based on symmetry, contour, and height after 1 repair was achieved in 64 of 67 patients. There were no overcorrections. Two patients underwent successful reoperation with a second conjunctival Müllerectomy with or without tarsectomy operation.ConclusionsThis modified algorithm and technique quantifies conjunctival Müllerectomy with or without tarsectomy ptosis surgery and yields predictable results.