Corneal optical quality following sub 1.8 mm micro-incision cataract surgery vs. 2.2 mm mini-incision coaxial phacoemulsification

ABSTRACT

To study and compare the effects of the micro-incision cataract surgery [MICS-sub 1.8 mm] and mini-incision coaxial phacoemulsification [2.2 mm] on the optical quality of the cornea characterized in terms of corneal aberrations. Fifty eyes underwent MICS and 50 mini-incision phacoemulsification, by the same surgeon. Both types of cataract surgery were performed using low ultrasound power and through a clear corneal incision, placed on the steepest corneal meridian ranging from 1.6 to 1.8 in MICS [Group I] and from 2.12 to 2.3 mm in mini-incision coaxial phacoemulsification [Group II]. Seidel and Zernike aberration coefficients and RMS values were obtained for a 6-mm pupil preoperatively and one month after surgery. The corneal astigmatism did not show statistically significant changes in either of the two groups-[MICS -0.73 +/- 0.63, -0.65 +/- 0.53 D, P = 0.25], [mini-incision phacoemulsification; -1.21 +/- 1.52, -1.00 +/- 1.19 D, P= 0.12]. The total RMS remained unchanged after MICS [1.77 +/- 1.7, 1.65 +/- 1.3 micro m, P= 0.18] and mini-incision phacoemulsification [2.00 +/- 1.87, 2.09 +/- 1.8 micro m, P = 0.41]. Statistically significant changes were found for coma [P = 0.004] and higher-order aberrations [P < 0.00l], showing MICS significantly less changes in cornea. Both MICS and mini-incision phacoemulsification do not degrade the optical quality of the cornea. Both surgeries do not induce a modification of the corneal astigmatism, even in the axis. It seems that 2 mm is the limit around which no optical changes are induced by cataract surgery in the human cornea