OF THE VARIOUS canthoplasties for lengthening the palpebral fissure, those of von Ammon,1 Agnew,2 and Blair3 all require sectioning of the lateral canthal ligament to give the necessary extension. Blaskovics4 simply resected a triangle of skin at the lateral canthus and pulled the conjunctiva out to cover the bared area. This gives the least satisfactory result. The following technique for lengthening a palpebral fissure has proved effective in my hands and has been most useful.
—The amount of fissure lengthening desired (usually 4 to 6 mm) is marked off from the lateral canthal angle, point AA′, to point B, with antiseptic dye. The lateral quarters of the upper and lower lids are split close to the posterior edge, and the whole area included in the broken line arc is undermined. The dissection is not carried beyond B since this is a fixed point.
Fox SA. Lengthening and Shortening the Palpebral Fissure. Arch Ophthalmol. 1971;86(4):401-403. doi:10.1001/archopht.1971.01000010403007