outcomes of clear cornea and scleral tunnel incisions for phacoemulcification

purpose: to compare clear corneal incision and scleral tunnel incision in terms of intraocular pressure (iop), post-operative inflammation, induced astigmatism, and corneal edema in phacoemulcification. methods: this non-controlled clinical trial was conducted on 78 eyes with senile cataract. a clear corneal incision was made in 40 eyes and a scleral tunnel incision was made in 38 eyes. all eyes underwent standard phacoemulsification. post-operative inflammation and corneal edema was measured 1, 7, and 60 days post-operatively. iop was also measured preoperatively and 1, 7, and 60 days post-operatively. corneal astigmatism was measured before and 7 and 60 days after surgery. results: post-operative inflammation was greatest on the first post-operative day in both groups, but there was no significant difference between them. in both groups, iop was highest on the first post-operative day with no significant differences at any times of follow up. mean decrease of iop at 2 month comparing to preoperative value was 1.4 mmhg in the scleral tunnel group and 1.1 mmhg in the clear corneal group. mean astigmatism preoperatively and on post-operative days 7 and 60 was 1.052±0.805, 0.993±0.653, and 0.730±0.527 diopter, and 0.893±0.850, 1.137±1.011, and 0.975±1.012 diopter in the scleral tunnel and clear cornea groups, respectively. astigmatism on days 7 and 60 were grater in clear cornea incision. against the rule induced astigmatism was more frequent in the clear corneal group. (p<0.04) in both groups, corneal edema was highest on the first post-operative day with no significant differences between the two groups. conclusion: scleral tunnel incision is better than clear corneal incision for minimizing post-operative corneal astigmatism in small incision cataract surgery.