Age-related difference in Lasik Treatment J. Orbegozo Gárate B. de Luis Eguileor V. Díaz Lacalle CENTRO OFTALMOLÓGICO INTEGRAL . BILBAO - SPAIN ASCRS /ASOA Chicago 2008

INTRODUCTION: In eyes after Lasik, the Higher Order Aberrations change (spherical aberration increase). Most changes to the total aberration pattern can be attributed to change in the anterior corneal aberrations. Marcos S. J Refract Surg 2001; 17:S596-S601. Moreno-Barriuso E, et al. Invest Ophthalmic Vis Sci 2001; 42:1396-1403. The balance between the aberrations of the corneal and the internal surfaces changes with the age. As the lens grows, its dimensions, surface curvatures, and refractive index change, altering the lens aberrations. Guiaro A, et al. J Opt Soc Am A 2000; 17:1697-1702. Tabernero J, et al. J Opt Soc Am A 2007; 24:3274-3283. Artal P, et al. Opt Soc Am A 2002; 19:137-143.

PURPOSE: To evaluate the High Order Aberrations (HOA) in eyes after Laser in situ keratomileusis (LASIK) as a function of age. METHODS: Preoperative Evaluation for the study: Corneal topography with Orbscan® IIz (Bausch & Lomb) Manifest and Cycloplegic refraction Analysis of HOA with CTView software LASIK performed with: Technolas® 217z system (Bausch & Lomb) Postoperative evaluation for the study: Total Wavefront analysis with the Zywave® aberrometer (Bausch & Lomb)

Spherical equivalent (D) METHODS: 40 MIOPIC EYES 2 groups: <45 years >45 years p Male/Female 40% / 60% 57,9% / 42,1% Age (years) 28,1±5,9 (22-43) 52,8±6,4 (46-64) Spherical equivalent (D) -4,7±1,3 [(-4,0)-(-7,5)] -4,9±2,4 [(-3,0)-(-8,0)] 0.76 Keratometry (D) 43,5±1,7 (40,4-45,8) 44,3±1,4 (42,5-46,8) 0.13

METHODS: 40 MIOPIC EYES 2 groups: <45 years >45 years Pachymetry (µm) 552±35 (500-611) 567±37 (500-630) 0.22 Ablation depth (µm) 89,42±25,4 (50-138) 88,7±28,9(40-134) 0.95 Optical Zone (mm) 6 Corneal Z40 6 mm (µm) 0.30±0.06 (0.13 – 0.39) 0.23±0.09 (0.10 – 0.37) 0.16

RESULTS: CORNEAL HOA (6 mm) (µm) < 45 years > 45 years p RMS HOA RMS 3rd RMS 4th CORNEAL HOA (6 mm) (µm) < 45 years > 45 years p RMS HOA 0.74±0.15 0.77±0.19 0.31 RMS 3rd 0.38±0.14 0.44±0.14 0.17 RMS 4th 0.57±0.12 0.57±0.15 0.67 Z-33 -0.04±0.15 -0.09±0.11 0.61 Z-13 -0.02±0.25 -0.05±0.24 0.88 Z13 0.05±0.22 0.03±0.28 0.64 Z33 0.04±0.17 0.03±0.22 0.91 Z04 0.54±0.12 0.52±0.15 0.77 No difference between both groups

RESULTS: TOTAL HOA (6 mm) (µm) < 45 years > 45 years p 0.53±0.22 RMS HOA RMS 3rd RMS 4th TOTAL HOA (6 mm) (µm) < 45 years > 45 years p RMS HOA 0.53±0.22 0.91±0.21 0.0002 RMS 3er 0.36±0.21 0.55±0.21 0.0027 RMS 4º 0.35±0.16 0.55±0.14 Z-33 -0.07±0.14 -0.16±0.12 0.037 Z-13 -0.22±0.20 -0.32±0.25 0.058 Z13 0.05±0.19 0.23±0.24 0.0066 Z33 -0.01±0.13 -0.04±0.18 0.43 Z04 0.33±0.16 0.53±0.12 <0.0001

RESULTS: INTERNAL HOA (6 mm) (µm) < 45 years > 45 years p RMS HOA RMS 3rd RMS 4th INTERNAL HOA (6 mm) (µm) < 45 years > 45 years p RMS HOA 0.52±0.18 0.60±0.21 0.13 RMS 3er 0.40±0.13 0.50±0.20 0.068 RMS 4º 0.30±0.13 0.25±0.13 0.63 Z-33 -0.03±0.09 -0.07±0.15 Z-13 -0.21±0.19 -0.26±0.22 0.17 Z13 0.03±0.19 0.22±0.35 Z33 -0.05±0.18 -0.10±0.19 0.44 Z04 -0.22±0.14 0.00±0.13 <0.0001

CONCLUSIONS: FOR THE SAME LASIK MYOPIC TREATMENT THE SPHERICAL ABERRATION INCREASES WITH THE AGE. The degradation of the ocular optics with age can be explained largely by the loss of the balance between the aberrations of the corneal and the internal surfaces. [Artal P, Berrio E, Guirao A. Contribution of the cornea and internal surfaces to the change of ocular aberratons with age. J. Opt. Soc. Am. A 19, 137-143 (2002)] Z04 0.51 μm Z04 0.44 μm Z04 0.07 μm ≥45 YEARS Z04 0.24 μm Z04 0.44 μm Z04 -0.24 μm <45 YEARS TOTAL TOTAL CORNEAL CORNEAL INTERNAL INTERNAL

CONCLUSIONS: OLDER SUBJECTS HAVE GREATER SPHERICAL ABERRATION (POSITIVE) THAT SUGGEST A MINOR DEPTH OF FOCUS AND WORSE NEAR VISION. “In patients with no accommodation, zero spherical aberration still provides the best quality image. However, a small amount of negative spherical aberration affords an improvement in near vision.” [Cheryl Guttmann. Researchers conclude zero spherical aberration equates with optimal visual performance. Eurotimes November 2007] ≥45 YEARS <45 YEARS 0.75 D 0.35 D 0.20 D 0.09 D -1.51 D -0.73 D Z04 0.51 μm Z04 0.24 μm

CONCLUSIONS: THE DEGRADATION OF THE OCULAR OPTICS THAT OCCURS WITH AGE INCREASE WITH LASER IN SITU KERATOMILEUSIS. THE RESULTS CAN BE WORSE FOR OLDER PATIENTS. CAN BE NECESSARY TO MEASURE THE TOTAL, INTERNAL AND CORNEAL ABERRATIONS IN THE PREOPERATIVE EVALUATION TO DETERMINE THE BEST TREATMENT IN A MYOPIC PATIENT.