Comparison of Phacodynamic Effects on Postoperative Corneal Edema Between 2.8 mm and 2.2 mm Microcoaxial Torsional Phacoemulsification

PURPOSE: To compare the effects of phacodynamic parameters on postoperative corneal edema between 2.8 mm and 2.2 mm microincisional coaxial cataract surgery. METHODS: A prospective randomized study design was conducted and included 144 cases randomly divided into 2 coaxial cataract surgery groups based on incision size, a 2.8 mm incision (n = 72) or a 2.2 mm microincision (n = 72). The cataract was graded using the lens opacity classification system (LOCS III). The total ultrasound time (TUT), cumulative dispersed energy (CDE), average torsional amplitude (ATA), fluid amount, and case time were measured for each surgery. Central corneal thickness (CCT) was measured preoperatively, and 1 day and 1 month postoperatively. Intraoperative parameters were correlated with postoperative corneal edema. RESULTS: The average nuclear opacity, intraoperative parameters, and postoperative corneal edema did not differ significantly between the 2 surgical groups. Regression analysis showed corneal edema to be significant in ATA (p = 0.028) in the standard (2.8-mm incision) coaxial group, whereas edema was significantly different with TUT (p = 0.001), CDE (p = 0.001), fluid amount (p = 0.021), and case time (p = 0.027) in the microcoaxial (2.2-mm microincision) group. CCT returned to baseline with an increase of 1.8% at 1 month. CONCLUSIONS: In the microcoaxial group, sustained ultrasound exposure and prolonged case time caused moderate postoperative corneal edema, while ATA was a significant factor in the standard coaxial group. These data can be used to devise an effective surgical strategy for cataract treatment.

Induced Astigmatism and High-Order Aberrations after 1.8-mm, 2.2-mm and 3.0-mm Coaxial Phacoemulsification Incisions

PURPOSE: To study theeffect of micro incision (1.8 mm) and small incision (2.2 mm and 2.8 mm) coaxial phacoemulsification on surgically induced astigmatism (SIA) and high-order aberrations (HOA) of anterior and posterior corneal surface. METHODS: The present randomized clinical study included 32 eyes having a 1.8-mm, 38 eyes having a 2.2-mm, and 30 eyes having a 2.8-mm corneal incision. SIAs were measured at 1 and 3 months postoperatively. HOAs included coma, trefoil, and spherical aberration. The coma-root mean square (RMS) and trefoil-RMS were evaluated at 1 month after the cataract operation. RESULTS: Surgically induced astigmatisms were 0.41 +/- 0.30 diopter (D) in the 1.8-mm incision group, 0.47 +/- 0.21 D in 2.2-mm group and 0.71 +/- 0.50 D in the 2.8-mm group. The SIA of the 1.8-mm group was smaller than the other groups (p = 0.002). There was no statistically significant difference in coma, spherical aberration of the corneal anterior surface and trefoil, or spherical aberration of the posterior surface among the 3 groups at 1 month after surgery. CONCLUSIONS: Incision size contributes to postoperative corneal astigmatism. Phacoemulsification cataract surgery with less than 2.8-mm incision does not significantly influence the corneal aberrationsof anterior and posterior corneal surfaces.