The role of incision site in the regional changes of corneal endothelial cells after phacoemulsification

PURPOSE:to determine the effect of the incision site on the corneal endothelium during phacoe mulsification procedure. METHODS:we studied prospect)vely 229 eyes that underwent phacoemulsification. Before surgery we evaluated endothelial cell density in 3 regions:superiorly ind inferiorly (approximately 2 mm from limbus) and centrally. This evaluation showed in 115 eyes ( 50.2%) an homogeneity of cellular density (with differences milnus then 2%), in the remaining eyes a vertical endothelial cell disparity, that was in 44 eyes (19.3%) more dense centrally, in 38 eyes (16.6%) more dense superiorly and in 32 eyes (13.9%) more dense inferiorly. We diviced the eyes into 2 groups (A and B) randomly:the group A was formed by 108 eyes in wich we carried but the incision in the site of the highest endothelial cell density ( scleral tunnel or temporal clear cornea), while in the 121 Eyes of group B we made a scleral superior tunnel. RESULTS:the mean endothelial cell loss was similar in the 2 groups: in group A -9.18%, -9.41%, -9.62% respectively at 1,6 and 12 months, in group B -9.32%, -9.53%, -9.80% in the same period With not statistical differences at T test. The regional differences in cell density demonstrete, neverthless, a better homogeneity in group A, with a difference between superior and central area of 0.8%, 1.3%, 1.1% at 1,6, 2 months, while in group B 3.1%, 3.1%, 3.3% at the same period. (p<0.05). CONCLUSIONS:the preoperative variations of endothelial regional density are important to guide the site of incision for phaco.