Corneal Optical Quality Following Sub 1.8 mm Micro-Incision Cataract Surgery vs. 2.2 mm Mini-Incision Coaxial Phacoemulsification.
OBJECTIVE
To study and compare the effects of the micro-incision cataract surgery (MICS-sub 1.8 mm) and miniincision coaxial phacoemulsification (2.2 mm) on the optical quality of the cornea characterized in terms of corneal aberrations.


METHODS
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.


RESULTS
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 mum, P = 0.18) and mini-incision phacoemulsification (2.00 +/- 1.87, 2.09 +/- 1.8 mum, P = 0.41). Statistically significant changes were found for coma (P = 0.004) and higher-order aberrations (P < 0.001), showing MICS significantly less changes in cornea.


CONCLUSIONS
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.
Alió
Jorge L
JL
VISSUM, Instituto Oftalmologico de Alicante, Spain.
Elkady
Bassam
B
Ortiz
Dolores
D