Effect of scleral shortening on axial length.

BACKGROUND Partial thickness sclerectomy is the most commonly employed scleral shortening technique used in conjunction with pars plana vitrectomy in the repair of myopia-associated macular holes in patients with staphyloma. Recently, scleral shortening induced through scleral invagination has been advocated as an adjunct in retinal translocation surgery. OBJECTIVE To determine whether a correlation exists between the amount of sclera infolding and the posttreatment reduction in axial length (AL) as a result of lamellar scleral resectioning or full-thickness scleral invagination. METHODS Three groups of 10 eyes each underwent lamellar scleral resection with dissection of 6, 8, and 10 mm in height, and 1 group of 10 eyes underwent a 10-mm invagination. Presurgical and postsurgical external AL of globes with stabilized intraocular pressure was measured to +/-0.022-mm precision. RESULTS Average (+/-SD) AL shortening following lamellar resections for 6-, 8-, and 10-mm groups were 1.50+/-0.24, 2.10+/-0.13, and 2.65+/-0.24 mm, respectively, and 2.50+/-0.23 mm for the 10-mm invagination group. Differences in AL before and after scleral shortening were found to be significantly different between dissections of different heights (P<.05), and not significantly different between the 10-mm resection and invagination groups (P>.17). The AL of each group was shortened by approximately 25% of the resection-invagination height. The relation was quasilinear. CONCLUSIONS Lamellar scleral resection and nonresected scleral invagination reduce the ocular AL. The extent of the reduction significantly correlates to the amount of removed or invaginated sclera. CLINICAL RELEVANCE Surgical shortening of the sclera is useful in the management of several retinal disorders, but causes significant changes in AL. Arch Ophthalmol. 2000;118:965-968