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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. Background and Purpose. - PowerPoint PPT Presentation
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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
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’)orafter 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?
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
Augenabteilung am St. Franziskus Hospital Münster
MethodsRefractive Baseline of the 2 groups before pharmaceutical
mydriasis Tropicamide 0.5% + Phenylephrine 2.5% Tropicamide 0.5%
Mean SD Min Max Mean SD Min Max
AberrometerSphere(D) -4.02 2.49 -9.26 0.52 -3.85 2.75 -9.45 6.6
Cyl(D) -1.20 0.92 -4.21 -0.05 -1.25 0.98 -5.77 0.64
Axis (°) 1 180 2 180
SE (D) -4.62 2.46 -9.41 -0.32 -4.48 2.79 -9.84 6.16
AutorefractorSphere(D) -4.21 2.38 -9.0 -0.25 -4.04 2.30 -9.25 2.5
Cyl(D) -0.95 0.87 -4.0 0.0 -1.01 0.81 -4.00 0
Axis (°) 0 179 0 179
SE (D) -4.69 2.31 -9.38 -0.63 -4.54 2.30 -9.88 2.25
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
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
Augenabteilung am St. Franziskus Hospital Münster
Z 3,-3 Z 3,-1 Z 3,1 Z 3,3 Z 4,-1 Z 4,-2 Z 4,0 Z 4,2 Z 4,4-0.05
0.00
0.05
0.03*
-0.01 -0.01 -0.01-0.01*
0.01
-0.02*
0.01 0.010.01
-0.01
-0.02*
0.010.00
0.01*
-0.01
0.000.00
group I group II
chan
ge o
f HO
A te
rms
[µm
]
Results: HOA
Group I: mydriasis with tropicamide 0.5% + phenylephrine 2.5%, n = 100Group 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
Augenabteilung am St. Franziskus Hospital Münster
Conclusion IEffect 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.
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.
Augenabteilung am St. Franziskus Hospital Münster
Thank you!
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