ASCRS 08 Changes Of Higher Order Aberrations After Excimer Laser Treatment For Moderate Myopia by Means of Preoperative Wavefront Aberration Levels using OPDCAT and OATz profiles of Nidek NAVEX system Uzeyir ERDEM MD Serkan Köksal MD Cornea & Refractive Surgery Dept. of GMMF ANKARA TURKEY

The authors have no financial interest in the subject matters of this presentation

Purpose: Analyzing changes in higher order aberrations (HOA) after two different ablation profiles (OATz and OPDCAT) for myopia using the Nidek NAVEX excimer laser system and comparing the groups for levels of preoperative higher order aberrations (HOAs)

Methods: We performed analysis of 126 eyes with low to moderate myopia and myopic astigmatism who undergone LASIK surgery. LASIK with the both Optimized Aspheric Treatment Zone (OATz) ablation profile and OPD-Customized Aspheric Treatment (OPDCAT) ablation profile was performed in 63 eyes. We performed analysis of 126 eyes with low to moderate myopia and myopic astigmatism who undergone LASIK surgery. LASIK with the both Optimized Aspheric Treatment Zone (OATz) ablation profile and OPD-Customized Aspheric Treatment (OPDCAT) ablation profile was performed in 63 eyes. The preoperative and postoperative UCVA and BSCVA,changes were recorded in logMAR units. All patients underwent a detailed ocular examination that included manifest and cycloplegic refractions, slitlamp evaluation, ultrasound pachymetry The preoperative and postoperative UCVA and BSCVA,changes were recorded in logMAR units. All patients underwent a detailed ocular examination that included manifest and cycloplegic refractions, slitlamp evaluation, ultrasound pachymetry

Material And Method  In both groups parameters have been optimized based on: – pachymetrie, –flap diameter, –And simulated for post operative changes at OATz or CATZ module of Final Fit software.  NIDEK MK 2000 microkeratome with 130 micron thin flap thickness used for both group  LASIK surgery were done at NIDEK's EC 5000 CXII platform.

Pre-op and post-op exams  After surgery we made 1 st day, 1 week, 1mo, and 3 and 6 month visits.  VA (UCVA, BCVA)‏  Subjective+ Objective+Cycloplegic Refraction  Slit lamp and Retinal Exam, TO  OPD-Scan ™ Autorefractometry+ keratometry Axial + Instantaneous topographic maps OPD + Internal OPD maps Refractive Map Total Wavefront + HO aberration maps PSF + Zernike Graph Mesopic and fotopic pupillometry

WF analysis Analysis of Wavefront Aberrations: Three measurements with OPD Scan wavefront aberrometer from each eye was evaluated using software that follows the standards for calculating and reporting the optical aberrations of eyes as proposed by Thibos and associates

1) Root-mean-square (RMS) of HOA from the third to eighth orders; 2) RMS of the total spherical aberration (TSA; square root of the sum of the squared coefficients of C 4 0, C 6 0, and C 8 0 ); 3) RMS of total coma (TC; square root of the sum of the squared coefficients of C 3 -1, C 3 1, C 5 -1, C 5 1, C 7 -1, and C 7 1 ); and 4) RMS of total trefoil (T3F; square root of the sum of the squared coefficients of C 3 -3, C 3 3, C 5 -3, C 5 3, C 7 -3, and C 7 3 ). 5) RMS of total tetrafoil (T4F; square root of the sum of the squared coefficients of C 3 -4, C 3 4, C 5 -4, C 5 4, C 7 -4, and C 7 4 )‏ 6) RMS of total high astigmatism (THiAst; square root of the sum of the squared coefficients of C 3 -5, C 3 5, C 5 -5, C 5 5, C 7 -5, and C 7 5 )‏ The parameters analyzed included

Statistical Analysis All statistical data were analyzed using the SPSS 11.0 (SPSS Inc, USA) statistical software. Descriptive statistical analyses of parameters and standard deviations were calculated Statistical differences were considered significant when P<0.05

Results 126 eyes (63 patients) Ages 29±3.6 in women, 27±4.1 in men, there were no difference related age and sex between groups.

Dr Üzeyir ERDEM 11 Safety  No lines of BCVA have lost in two group after surgery  No serious flap complications

Results WFA OATz: −5.14+/-1.59 D OATz Pre Op3rd mo Post OpP Mean RMS HOA 0.40±0.15 µm 0.45±0.14 µm0.017 T.Coma 0.17±0.10 µm 0.24±0.12 µm0.001 T.SA 0.09±0.07 µm 0.19±0.12 µm0.001 T. trefoil, decr. 0.27±0.13 µm 0.23±0.11 µm OPD CAT: −4.40+/-1.53 D Mean RMS HOA 0.19±0.17 µm 0.25±0.15 µm0.001 T.Coma 0.19± ±0.15 µm T.SA 0.10±0.08 µm 0.16±0.10 µm0.001 T. trefoil, decr. 0.25±0.13 µm 0.24±0.17 µm HOAs, TC, TSA increase is significiant

Dr Üzeyir ERDEM 13 RMS value changes of OPD CAT and OATz Group  OPDCAT HOAs RMS values increase at 3rd Mo. Pre- Op HOAs RMS < 0.3 RMS increase 88% Pre- Op HOAs RMS >0.3 HOA increase 4.3% (p=0.001)  OATz HOAs RMS values increase at 3rd Mo. Pre- Op HOAs RMS < 0.3 RMS increase 92% Pre- Op HOAs RMS >0.3 HOA increase 14.5% (p=0.001)

Dr Üzeyir ERDEM 14 Refractive Outcome 1st Mo

Dr Üzeyir ERDEM 15 Refractive Outcome 3rd Mo

Dr Üzeyir ERDEM 16 OPD CAT 3rd Mo

Dr Üzeyir ERDEM 17 OATz 3rd Mo

Dr Üzeyir ERDEM 18 Stability of Refractions Postop Follow-up 3 ay1 ay2 hfPreop SE(D) Postop Follow-up 3 ay1 ay2 hfPreop SE(D) OPD CATOATz

Results LASEK with Nidek NAVEX platform with the OATz and OPD CAT ablation profile was safe and effective in correcting high myopic astigmatism comparing to other high myopia treatment options LASEK with Nidek NAVEX platform with the OATz and OPD CAT ablation profile was safe and effective in correcting high myopic astigmatism comparing to other high myopia treatment options WF aberration changes similar for low and moderate myopia WF aberration changes similar for low and moderate myopia HOA increased in both group but increse amount is far less in high(>0.3 ) RMS group. HOA increased in both group but increse amount is far less in high(>0.3 µm ) RMS group.

Conclusions: The comparison between LASIK custom (OPD CAT) and conventional (CATz) shows that there is a tendency of improvement on spectacle correction, and better predictability on the Custom treatment group. Quick dedection of irregularity with OPD-Scan and the correction of corneal irregularities and aberrations with Final Fit software, and 1 mm multipoint ablation module of NIDEK laser looks promising for better results.

Dr Üzeyir ERDEM 21 Conclusions  The amount of increase in postoperative higher order aberrations in both groups was acceptable after myopic LASIK surgery. Nevertheless, the eyes with low amounts of preoperative aberrations showed a marked increase in aberrations following wavefront guided treatment; therefore, wavefront treatment may not be beneficial for all eyes.  Longer follow up and larger series would be needed for better understanding.