Analyzing Spherical Aberration Preoperatively and After Implantation of Trifocal Versus Multifocal Diffractive IOL
Purpose
The purpose of our study is to compare the evolution of the preoperative spherical aberration (z 400) and after cataract surgery using trifocal and multifocal I.O.L. aspheric intraocular diffractive lenses, regarding the total amount and the change of the sign (wether it was positive or negative).
Methods
This is a retrospective study from 40 patients (24 women/ 16 men), age 50-75 y/o and average of 67, who underwent cristalline lens or cataract surgery,all made by the same surgeon(J.S.N.), we take Hartmann-Shack aberrometry pre and postop , and comparing the results of the z400 in microns. We use the same technique for both procedures phacoemulsification with 2.2mm M.I.C.S., the trifocal Atlisa tri 839MP IOL was from Zeiss and the multifocal was the Restor SN6AD1 with +3D add. All patients had no previous surgery or eye pathology.
We use for statistical porpouses the S.P.S.S. 15 for windows,applying the students T test, if the p value was less than 0.05 was considerated statistically significant.
Results
the results shows the following results, from the trifocal I.O.L. we had: a preop z400 mean 0.30μ (0.15/0.40μ) , after the surgery mean 0.08μ(-0.08-0.30μ ) p value 0.01.
On the multifocal I.O.L. we had a preop z400 mean 0.25μ (0.10-0.40μ) , after the surgery m 0.10μ (0.06-0.30μ ) showing a p value of < 0.05.
Statistical analysis :p values postop trifocal vs multifocal.
Conclusion
With this kind of lenses we have statistical significant reduction of the z400 in both groups when comparing with the preop status. It was no difference between trifocal versus multifocal diffractive I.O.L., so clearly the aspheric lenses reduce the amount of the spherical aberration.