Abstract
Purpose: :
to analyze the effects of the miniincision coaxial phacoemulsification (2.2 mm) combined with bimanual irrigation/aspiration (I/A) on the optical quality characterized in terms of corneal and total aberrations.
Methods: :
One hundred and seventy eyes underwent mini-incision phacoemulsification, by the same surgeon. Cataract surgery was performed using low longitudal ultrasound power associated with torsionnal power (OZIL®) through a clear corneal incision of 2.2mm, placed at 130°. Two paracentesis of 1mm were performed 90° apart for bimanual irrigation/aspiration. Intraocular lens (IOL) implantation were performed with an asphéric IOL (Alcon® SN60WF IQ). An aberrometry (OPD scannII, Nidek®, Japan) was performed preoperatively (Day 0), 15 days after surgery (Day 15) then 1 month after (M1).
Results: :
The corneal astigmatism did not show statistically significant changes neither between Day 0 and M1 (-0,92 ± -0,13D vs -0,89 ± 0,15D, p=0,2), nor between Day 15 and M1 (1,02 ± 0,24D vs 0,89 ± 0,15D, p=0,35). Astigmatism is slightly modified in the axis : mean rotation was 34,5°± 13,4 at Day 15 and 31,9°± 12,2 at M1. The difference between Day 15 and M1 was non significant (p=0,67). The total Root Mean Square (RMS) remained unchanged after this technique (0,50 ± 0,27 μm vs 0,46 +/-0,29 μm, p=0,42). The corneal RMS do not change significantly (0,98 ± 0,34 vs 1,14 ± 0,39, p=0,13). Corneal aspherical aberrations do not change significantly too (p<0,001). The H/B ratio (quality of vision) is statistically improved between Day 0 and Month 1 (0,404 ± 0,025 versus 0,552 ± 0,076, p=0,001).
Conclusions: :
These procedure do not degrade the optical corneal quality in the human cornea. Although the cornea shows slightly astigmatic changes in the axis, these 3 incisions procedure permits a neutral power surgically induced astigmatism through a 2.2 mm main incision that is well respected at the end of surgery thanks to bimanual IA. The stability of refractive data between Day 15 and M1 allows early spectacles prescription and a quick return to normal life. These results are mostly important especially for premium IOL that can be injected through 2.2mm whatever their material.