PREDICTING IOL OUTCOMES

Binocular testing with an adaptive optics-based vision simulator can accurately predict patients’ visual performance under binocular conditions with different monofocal and multifocal intraocular lens (IOL) designs, according to a study presented by Pablo Artal PhD at the XXXII Congress of the ESCRS in London.

“Our findings validate the use of laboratory adaptive optics instruments as a useful tool for developing new IOL optics and implementing clinical scenarios for demonstrating the efficacy of new lenses,” said Dr Artal, Laboratorio de Optica, Universidad de Murcia, Murcia, Spain.

The first part of the study involved five volunteers who underwent binocular high contrast through-focus visual acuity measurement with SLOAN letters, while using the adaptive optics visual simulator to induce phase profiles corresponding to five different IOL designs, two refractive monofocal lenses and four diffractive multifocal lenses.

Later, Dr Artal and his associates compared the results obtained in the volunteers with the adaptive optics vision simulator to the clinical outcomes measured in three different clinical trials involving patients implanted with the corresponding IOL models. In all clinical trials, patients underwent binocular high contrast defocus visual acuity testing between one and three months postoperatively with an ETDRS chart using trial lenses, with a best distance correction in place, according to common clinical practice.

“The purpose of this study is to compare the clinical visual outcomes measured in patients implanted with different IOL models to those previously obtained by visual simulation using the phase profiles generated by the same IOLs,” noted Dr Artal.

Dr Artal noted that they carried out the testing under laboratory conditions before the IOLs were available for clinical use and the actual clinical results with the lens only became available in recent years. All of the trials included at least 10 eyes implanted with the lenses under investigation. One of the refractive lenses had a spherical aberration value of +0.17 microns, the remaining IOLs had a negative spherical aberration of -27 microns. The multifocal IOLs had near adds of +4D, +3.25D and +2.75D.

The average through-focus visual acuity measured in clinical studies correlated closely with that measured with the adaptive optics visual simulator for the IOL models evaluated. The cross correlation coefficient between visual simulation and clinical data ranged from 0.960 to 0.995.

“Our findings show that through-focus high contrast visual acuity testing, using the phase profile provided by different IOLs with an adaptive optics vision simulator under binocular conditions, predicts the results that will be obtained in real patients implanted with the same IOLs,” Dr Artal concluded.

This is a remarkable validation of the use of adaptive optics technologies to predict visual outcomes of newly developed IOL models.

Pablo Artal: pablo@um.es