ABSTRACT
To compare the astigmatic outcomes of phacoemulsification cataract surgery using temporal versus nasal clear corneal incisions. In a clinical trial, consecutive patients with senile cataracts underwent phacoemulsification and implantation of a hydrophobic acrylic foldable intraocular lens through a horizontal clear corneal incision [temporal in right and nasal in left eyes]. Outcome measures included keratometric astigmatism and surgically induced astigmatism [SIA] calculated by the vector analysis method using the Holladay-Cravy-Koch formula. The nasal and temporal groups consisted of 20 eyes each. Mean preoperative keratometric astigmatism was 0.63 +/- 0.48 D and 0.38 +/- 0.39 D in the temporal and nasal incision groups respectively [P=0.09]. Data on 10 eyes in each study group was available for the six-month analysis. Mean keratometric astigmatism was as follows in the temporal and nasal groups respectively: 0.85 +/- 0.47 D versus 1.95 +/- 0.45 D at 1 week [P < 0.001], 0.73 +/- 0.46 D versus 1.79 +/- 0.55 D at 4 weeks [P < 0.001], and 0.63_0.30 D versus 1.05 +/- 0.56 D at 6 months [P = 0.053] after surgery. SIA at the same follow-up intervals was 0.71 +/- 0.20 D versus 1.80 +/- 0.22 D [P < 0.001], 0.63 +/- 0.20 D versus 1.65 +/- 0.31 D [P < 0.001] and 0.26 +/- 0.46 D versus 0.92 +/- 0.36 D [P=0.002] in the temporal versus nasal incision groups respectively. Temporal clear corneal phacoemulsification induces significantly less astigmatism as compared to similar surgery using the nasal approach