Measurement of corneal aberrations for customisation of intraocular lens asphericity: impact on quality of vision after micro-incision cataract surgery

Abstract

Individual selection of IOL asphericity with a preoperative corneal SA measurement allowed control of final ocular SA. Such customisation improves mesopic contrast sensitivity, and leads to better objective quality of vision.

Clinical Study of Customized Selected Aspherical Intraocular Lens Implants

“…The results showed that contrast sensitivity in the mesopic and mesopic with glare conditions at middle and high spatial frequencies was better in the experimental vs. the RA group. This finding is in agreement with a similar recent study by Nochez et al [8] in which patients were implanted with zero-aberration Acri.Smart 46LC lenses (the reference group) or Acri.Smart36A lenses (experimental group) based on pre-surgical corneal spherical aberration. These authors showed that under mesopic conditions at high spatial frequencies, the contrast sensitivity was significantly better in the experimental group.…”

“…However, we found a mean absolute predictive error of 0.046 ± 0.079 μm for postoperative SA in agreement with Nochez et al [8] (0.040 ± 0.047 μm) and very similar to that of Packer et al [9] (0.058 ± 0.056 µm) who tested three different IOLs (AO, AcrySofIQ and Tecnis). Minor variations in predictive value were explained as a result of the postoperative aperture size being limited by the capsulorhexis and by variations in pupil dilatation [9].…”

“…Although the total spherical aberration was not significantly different between the experimental and RA patients three months after surgery, a higher proportion of experimental patients fell within the targeted range compared to RA patients. Nochez et al [8] performed a customized selected aspherical intraocular lens implantation in order to produce a residual ocular SA close to +0.10 μm and achieved a final ocular SA of 0.085 ± 0.084 μm after surgery. Packer et al [9] selected an aspheric IOL for implantation based on preoperative corneal spherical aberration and the labeled IOL (AO, AcrySof IQ and Tecnis Z9002) spherical aberration, such that the arithmetic sum of these two values was closest to zero.…”

Simulation of the Through-Focus Modulation Transfer Functions According to the Change of Spherical Aberration in Pseudophakic Eyes

“…Our results indicate statistically significant differences between eyes with increased aMTF and those with decreased aMTF in the vertical coma and tetrafoil ( Table 3). Previous studies found that corneal SA and coma did not change significantly with corneal incision and that other HOAs also did not change, especially after micro-incision cataract surgery [15,29]. Therefore, it could be assumed that relatively high preoperative corneal HOA might be a negative predictive factor of optical outcomes using aspheric IOLs.…”

“…However, there is no clear target SA for optimal visual outcome [12]. Some studies indicated that complete correction of SA improved visual performance, but some model-eye studies could not indicate best visual quality for a fully corrected SA [12][13][14][15]. Inter-subject variability and interaction of the different sources of optical aberration may also make it difficult to determine the ideal SA of an IOL [16,17].…”