ABERRATIONS IN PATIENTS IMPLANTED WITH LIGHT ADJUSTABLE INTRAOCULAR LENSES Pablo Artal, Encarna Alcón, Eloy Villegas, Carmen Cánovas, Elena Rubio*, José M. Marín* LABORATORIO DE OPTICA, UNIVERSIDAD DE MURCIA, SPAIN * Hospital Virgen de la Arrixaca, Murcia, SPAIN Supported by: Reserch funding and consulting reimbuserment provided by Calhoun Vision, USA

Refractive errors (defocus & astigmatism) produce the most deleterious impact in vision after cataract surgery Best focus (0 D, 0 D) Refractive error (1 D, 1 D)

Light adjustable intraocular lenses (LALs) Light adjustable intraocular lenses (LALs)* allow nearly PERFECT refractive outcomes and improved quality of vision after cataract surgery Spatially resolved irradiation hn hn "lock-in" To illustrate how the material works, imagine a lens in which the lens power needs to be increased. The central zone of the lens is irradiate to cause the macromer there to polymerize. Then time is allowed for free macromer to diffuse down the resulting concentration gradient. The central zone bulges, the radius of curvature decreases, the focal length decreases. Similarly, if the macromer has a higher refractive index than the matrix, this procedure would increase the refractive index in the central zone, further enhancing the increase in lens power. Irradiating on the periphery causes macromer to leave the central zone, causing it to flatten and increasing the focal length. Furthermore, any arbitrary wavefront correction can be written into the lens using the corresponding spatial distribution of light. Once the desired state of the lens is reached, the entire lens may be irradiated to polymerize all the macromer, making the state of the lens permanent. Then the optic can be exposed to UV light (e.g., sunlight) and remain unaltered. *

LALs procedure: + Surgery Two weeks adjustment + lock-ins Corneal stabilization This is an example of the complete procedure. After standard surgery, two weeks are waited to allows corneal stabilization. Then light adjustments are performed to correct the remining refractove errors. Once optimum refraction is obtained, the lenses are lock. During this period pateints wear protective spectacles to avoid any change sin the lenses produce by sun light

64 patients implanted with LALs have been carefully measured with an objective WAVEFRONT approach for refraction and aberration control through the whole treatment process PARAR….WE perfomeed a study in sixty four patients implanted with this adjuatebale lenses to evalaue the optical changes induced by the treatments. Refraction and aberrations were measured using an objective wavefront approach.

Example of eye’s (all) aberrations treatment lock-ins Pre adjustment Post_1ºadjustment Post_lock-in1 Post_lock-in 2 stability Post_3months Induced wavefront by treatment

Effect of light profiles in LAL’s aberrations Hyperopic Myopic Astigmatic light treatments… Beyond the primary effect of correction refractove errors, the light tretaments may also induce higher order aberrations in the lenses. To study this issue, we also develop a procecedure to meaure the aberrationsinduce inthe lenses.

(Artal and Guirao, Opt.Lett., 1998; Artal et al., JOV,2001) LAL = eye - cornea (Artal and Guirao, Opt.Lett., 1998; Artal et al., JOV,2001) - = ? - = The aberration of the LAL were obtained by direct substraction of WA to the complete eye and the cornea. Eye mesure by HS and corenal by ray-tracing tfrom corneal topography data.

INDUCED ABERRATIONS BY LIGHT TREATMENT D RMS (mm) IN the next slides I will show some of teh results. These are the induced aberrations by each treatment (expresed in RMS) are represented in this plot. First are placed the spherical adjustment and then the astigmatism one. While small amounts of aberrations are induced, we noted that two partciular profiles produced signfiant higher levels of aberrations: 4mm pupil

Impact of induced aberrations by treatment in visual acuity Best corrected VA PARAR… An important point is to know if these induced aberration may compromise visual acuity. This figures shows BEST CORRECTED VA for all the light treatments before and after the teratents. We did not found any signficant difference, EVEN….

Stability of the adjustable IOLs after lock-in: changes in LAL’s wavefront? RMS microns after treatment after one month A final point I wwould like to show you is that the lenses remain actually stable after lock-ins. Wavefront analysis allows tis to follow the shape pof the lesnes (and teh aberrations) and they were stable over time.

Conclusions i) The light adjustment profiles induced small amounts of high order aberrations, except for the myopic astigmatism and myopic treatments ii) These induced aberrations did not compromise visual acuity iii) The aberrations in the LALs remained nearly constant up to 1 year post-surgery iv) These results indicate the potential ability of LALs to effectively control the eye´s aberrations