Análisis de la influencia de la posición de lentes intraoculares de cámara posterior sobre la calidad de visión

Abstract

This doctoral thesis has been performed at the Institute of Applied Ophthalmobiology (IOBA) of the University of Valladolid (Valladolid, Spain) under the supervision of Dr. Miguel J. Maldonado López and Dr. Alberto López Miguel. Additionally, one of the studies has been designed and performed at the School of Health Professions of the University of Plymouth (Plymouth, United Kingdom) under the supervision of Dr. Phillip Buckhurst, allowing this thesis to apply for the “international doctorate” mention. Posterior chamber intraocular lens (IOL) implantation has been widely accepted not only to correct refractive errors (phakic IOLs), but also to replace the crystalline lens after phacoemulsification (pseudophakic IOLs). This doctoral thesis aims to contribute to new knowledge about the effect of the location of current posterior chamber IOL designs on the quality of vision (QoV) and quality of life (QoL). OBJECTIVES First, to analyze the effect of the central KS-AquaportTM location in the phakic EVO Visian ICL® on the QoV under mesopic conditions as well as on the QoL of postoperative subjects. Second, to prospectively assess the short-medium term effect of the phakic EVO+ Visian ICL® implantation on the visual performance, QoV and QoL. Third, to analyze the effect of the central KS-AquaportTM location in the phakic EVO+ Visian ICL® on the visual performance, QoV and QoL depending on the postoperative time. Fourth, to analyze the effect of the decentration and tilt of the aspheric pseudophakic intraocular lens Tecnis® ZCB00 on the monochromatic wavefront aberrations postoperatively. METHODS Three studies were performed: An ambispective study was performed to assess 30 eyes of 30 patients implanted with EVO Visian ICL®. The central hole location was determined using combined slit-lamp biomicroscopy imaging and a dual Scheimpflug imaging system. The visual acuity (VA), mesopic contrast sensitivity (CS), CS under halogen-type glare, CS under xenon-type glare, photostress recovery time after glare were evaluated, and de Boer scale, and Quality of Life Impact of Refractive Correction (QIRC) questionnaire was administered. Multiple linear regression models were used to analyze the effect of the central hole location on parameters using the pupil center and visual axis as references based on cartesian and polar coordinates. A prospective study including five visits: preoperatively and 1 week, and 1, 3 and 6 months postoperatively, was conducted to analyze 36 eyes of 36 patients who underwent EVO+ Visian ICL®. The central hole location was estimated using the same methodology as in the previous ambispective study. Additionally, corneal magnification was calculated based on Gaussian optics in paraxial approximation. VA, mesopic CS, CS under halogen-type glare, CS under xenon-type glare, photostress recovery time after glare were evaluated, and the de Boer scale, the QoV and QIRC questionnaires were administered; finally, ring-shaped dysphotopsia was also assessed. Linear, cumulative link and logit mixed models were fitted to analyze the effect of the EVO+ implantation. Multivariate regression models were performed to analyze the effect of central hole location, including cartesian coordinates or polar coordinates, on QoV and QoL parameters. A prospective study was performed to analyze 33 eyes of 33 patients implanted with a pseudophakic intraocular lens (IOL) (Tecnis® ZCB00). VA evaluation, wavefront aberration measurement and cross-sectional imaging using a swept-source optical coherence tomography (SS-OCT) were accomplished. Twelve sectional SS-OCT images per subject were analyzed following an optical distortion correction. Decentration and tilt of the IOL were calculated based on 2 reference systems (pupil center and iridocorneal angles) using cartesian and polar coordinates. Multiple linear regression models including the cartesian coordinates or polar coordinates were used to analyze the effect of the decentration and tilt on aberrometric variables. RESULTS Under all testing circumstances, EVO central hole decentration did not affect the VA or CS. With the visual axis as a reference, worse QIRC values were associated with greater upward central hole displacement (β = -9.34, p = 0.03) and a lower polar angle value (β = 0.08, p = 0.01). Using the pupil center as a reference, greater nasal central hole decentration was associated with longer xenon glare photostress recovery time (β = 7.17, p = 0.002). Following EVO+ implantation, VA significantly (p ≤ 0.01) improved at the four postoperative visits. Mesopic CS progressively improved at 1-, 3- and 6-months postoperatively (p ≤ 0.01). Halogen glare CS decreased at 1 week and halogen and xenon glare CS improved at 6 months (p ≤ 0.02). Photostress recovery time after halogen glare improved at 3 and 6 months (p ≤ 0.004). QoV scores improved at 1 week, and 3 and 6 months (p ≤ 0.001). QIRC scores improved postoperatively (p < 0.001). Ring-shaped dysphotopsia decreased at 3 and 6 months (p ≤ 0.01). EVO+ central hole decentration was associated with moderate VA loss at three month postoperative visit using visual axis as a reference, in cartesian (X coordinate: β = -0.31, p = 0.004) and polar coordinates (radius: β = 0.32, p = 0.01). Under all lighting circumstances, EVO+ central hole decentration did not affect either the CS or the bothersome of incoming glare. However, using the visual axis as a reference, inferior central hole decentration was associated with longer xenon glare photostress recovery time (β = -3.83, p = 0.02) at 1-week postoperative visit. Lower radius of EVO+ central hole decentration using pupil center as reference, was associated with improved QoV scores (β ≤ 70.91, p ≤ 0.01) at 1-month postoperative visit. Temporal decentration of EVO+ central hole respect to the pupil center produced higher ring-shaped dysphotopsia (severity scale) at 3-month postoperative visit (X coordinate: β = -2.02, p = 0.01). EVO+ central hole decentration did not affect the QIRC questionnaire regarding any reference system (p ≥ 0.14). Tecnis® ZCB00 decentration using the pupil center as a reference had a significant effect on ocular horizontal coma (X coordinate: β = 0.11, p = 0.03; Y coordinate: β = 0.13, p = 0.004) and vertical tetrafoil (X coordinate: β = 0.08, p = 0.03) aberrations. Additionally, decentration using as a reference the line joining iridocorneal angles showed that temporal displacement was associated with higher ocular and internal horizontal trefoil (β = -0.19, p = 0.03 and β = 0.27, p = 0.01, respectively). Decentration using iridocorneal angles as a reference had a significant effect on ocular primary coma (X coordinate: β = -0.10, p = 0.02; Y coordinate: β = -0.09, p = 0.001), total coma (X coordinate: β = -0.10, p = 0.02; Y coordinate: β = -0.09, p = 0.001), vertical secondary astigmatism (Y coordinate: β = 0.08, p = 0.001; polar angle: β = -0.01×10-3, p = 0.004) and secondary spherical aberration (radius: β = -0.02, p = 0.02). Tecnis® ZCB00 tilt using iridocorneal angles as a reference had a significant effect on the ocular secondary spherical aberration (Y coordinate: β = -0.001, p = 0.02). CONCLUSIONS First, the location of the phakic intraocular lens EVO Visian ICL® central KS-AquaportTM, respect to the pupil center and visual axis, does not affect QoV when decentration values are representative of the ones usually found in the clinical practice. However, a nasal central hole decentration is likely to result in longer photostress recovery time after glare. Moreover, upward decentration might be associated with decreased patient-perceived vision-related QoL. Second, the implantation of the phakic intraocular lens EVO+ Visian ICL® produces a transient decrease in CS in conditions similar to those observed during night driving at early postoperative time, improving the preoperative values from the 1-month postoperatively. In addition, the ring-shaped dysphotopsia perception decreases progressively achieving higher QoV and QoL levels during the short-medium follow-up, reaching better values than preoperative ones. Third, an accurate centration of the phakic intraocular lens EVO+ Visian ICL®, respect to the pupil center and visual axis, allows higher QoV levels, with a low perception of dysphotopic phenomena during the short-term follow-up. In addition, the KS-AquaportTM location does not affect CS under mesopic glare when decentration values are representative to the ones commonly observed after uneventful surgeries. Moreover, central hole decentration does not affect the QoL of postoperative patients during the short-term follow-up. Fourth, the intraocular lens decentration and tilt values commonly observed after the implantation of the aspheric pseudophakic IOL Tecnis® ZCB00, respect to the pupil and iridocorneal angles reference systems, result in ocular and internal higher order aberrations that are not high enough to negatively affect QoV from a clinically relevant view-point.