Increasing predictability

Trifocal IOL yields good results in eyes that have had previous laser ablation

Roibeard O’hEineachain

Posted: Monday, April 1, 2019

Spherical equivalent refraction accuracy

Optimised IOL calculations can further improve the refractive predictability of the FineVision trifocal IOL in presbyopic patients who have previously undergone excimer laser corneal refractive surgery, Luis Brenner MD told the 36th Congress of the ESCRS in Vienna, Austria.

Luis Brenner MD

Dr Brenner, Oslo, Norway, presented the results of a multi-centre retrospective single protocol study involving 241 eyes of 123 patients who had undergone previous PRK, LASIK or LASEK and underwent presbyopic RLE with FineVision trifocal lens implantation during the years 2015-2017 at Memira Clinics in Scandinavia.

The results showed that 85% of patients achieved binocular uncorrected distance and near visual acuities of 0.9 and J3, respectively. In addition, 80.9% were within 0.5D of predicted postoperative refraction and 97.9% of eyes were within 1.0D at the three months, Dr Brenner said.

Dr Brenner noted that from 2016 they included IOL constant optimisation and a nomogram to correct for prediction errors to the online ASCRS IOL calculator. They found that the mean refractive error was -0.29D for the standard calculation group compared to only -0.14D for the optimised calculation group. In addition, only 76% of eyes were within 0.5D of target refraction in the standard calculation group, compared to 84% of the eyes in the optimised group.

The study included 155 eyes (64.3%) that had undergone previous myopic ablations. Among those with prior refractive data, the mean manifest refraction spherical equivalent (MRSE) was -3.05D (range: -0.75 to -7.00D). Also included were 86 eyes (35.7%) that had undergone hyperopic ablations. Among those with previous data, the mean MRSE was +1.99 to 0.84D (range: 0.00 to +4.00D).

All eyes in the study were presbyopic to the point that a 1.50D add for near vision tasks was required. The study’s exclusion criteria were abnormal optics determined by topography, de-centred ablations, high ametropic ablations and corrected distance visual acuity of less than 0.8.

Prior to implantation of the trifocal IOL, the myopic ablation group had a Snellen corrected distance visual acuity CDVA of 1.09, an uncorrected near visual acuity (UNVA, American point type) of 12.42 and an MRSE of -0.06. Following implantation of the IOL, the group had mean Snellen uncorrected distance visual acuity (UDVA) of 0.88, a UNVA of 5.11 and an MRSE of -0.25D.

In the hyperopic ablation group, prior to implantation of the presbyopic IOL the mean corrected distance visual acuity CDVA was 1.05, the mean UNVA was 18.47 and the mean MRSE was +1.05D. Following implantation of the trifocal lens, the mean Snellen UDVA was 0.85, the mean UNVA was 5.25 and the mean MRSE was -0.02D.

Luis Brenner MD,