1. Augenabteilung am St. Franziskus Hospital Münster Influence of Mydriatic Eye-drops on Wavefront-sensing and Automated Refraction Taneri S, Oehler S, MacRae S M, Yoon G The authors have no financial interest in the subject matter of this poster. ASCRS, March 25-29, 2011, San Diego

2. Augenabteilung am St. Franziskus Hospital Münster Background and Purpose Wavefront-guided ablations are based on wavefront sensing: in a pupil dilated under mesopic conditions (in this poster entitled ‘miosis’) or after the application of mydriatic eye-drops (in this poster entitled ‘mydriasis’) Question: Is there an influence of mydriatic eye-drops on wavefront-sensing in terms of the phoropter- predicted-refraction (PPR) of the Zywave aberrometer or on automated refraction?

3. Augenabteilung am St. Franziskus Hospital Münster Methods Prospective study of 200 myopic eyes, measured in dim light and pharmacologically induced mydriasis with an aberrometer (Zywave) and with automated refraction Comparison of Predicted Phoropter Refraction (PPR) for a pupil diameter of 3.5 mm with and without pharmaceutical mydriasis, respectively 100 eyes dilated with tropicamide 0.5% + phenylephrine 2.5% eye-drops, 100 eyes with tropicamide 0.5% alone

4. Augenabteilung am St. Franziskus Hospital Münster Methods Refractive Baseline of the 2 groups before pharmaceutical mydriasis Tropicamide 0.5% + Phenylephrine 2.5%Tropicamide 0.5% MeanSDMinMaxMeanSDMinMax Aberrometer Sphere(D)-4.022.49-9.260.52 -3.852.75-9.456.6 Cyl(D)-1.200.92-4.21-0.05-1.250.98-5.770.64 Axis (°)11802 SE (D)-4.622.46-9.41-0.32-4.482.79-9.846.16 Autorefractor Sphere(D)-4.212.38-9.0-0.25-4.042.30-9.252.5 Cyl(D)-0.950.87-4.00.0-1.010.81-4.000 Axis (°)01790 SE (D)-4.692.31-9.38-0.63-4.542.30-9.882.25

5. Augenabteilung am St. Franziskus Hospital Münster Results: Aberrometer PPR values obtained in mydriasis were less myopic than in miosis Mean ± SD SE (D)Sphere (D)Cylinder (D) Tropicamide 0.5% + Phenylephrine 2.5% -0.36 ± 0.36 *-0.33 ± 0.36 *-0.07 ± 0.27 Tropicamide 0.5% -0.24 ± 0.43 *-0.24 ± 0.35 *-0.00 ± 0.35 Difference between dim light pupil dilation and pharmacologically induced mydriasis *: statistically significant

6. Augenabteilung am St. Franziskus Hospital Münster Results: Sphere & Spherical Equivalent Aberrometer and autorefractor displayed a hyperopic shift of sphere and spherical equivalent in most eyes Hyperopic shift of spherical equivalent with tropicamide and tropicamide combined with phenylephrine was significant with both devices (aberrometer and autorefractor) No difference between the two mydriatic solutions were found Aberrometer was more affected by mydriatic eye drops than the autorefractor Age had no influence on the amount of the difference

7. Augenabteilung am St. Franziskus Hospital Münster Results: HOA Group I: mydriasis with tropicamide 0.5% + phenylephrine 2.5%, n = 100 Group II: mydriasis with tropicamide 0.5 %, n = 100 Applying tropicamide alone or combined with neosynephrine lead to significant inaccuracy in the determination of some HOA terms Change of HOA after pharmacologic pupil dilation Statistically significant

8. Augenabteilung am St. Franziskus Hospital Münster Conclusion I Effect on lower order aberrations There seems to be a cycloplegic effect from mydriatic eye- drops as both aberrometer and autorefractor displayed a significant hyperopic shift of sphere and spherical equivalent in most eyes. The range of difference for the sphere component of the PPR was >1.5 D in both groups. This is much higher than the accuracy of modern excimer lasers and may partially account for clinically significant over- or undercorrection of defocus in laser vision correction.

9. Augenabteilung am St. Franziskus Hospital Münster Conclusion II The hyperopic shift after pharmaceutic pupil dilation should be taken into account when interpreting aberration measurements and planning a wavefront- guided ablation. Consequently, it seems ideal to avoid the wide-spread use of mydriatics prior to wavefront sensing by mathematical expansion of data measured over a naturally dilated pupil.

10. Augenabteilung am St. Franziskus Hospital Münster Thank you!