Measurement of Ex Vivo Porcine Lens Shape During Simulated Accommodation, Before and After fs-Laser Treatment

TY - JOUR

T1 - Measurement of Ex Vivo Porcine Lens Shape During Simulated Accommodation, Before and After fs-Laser Treatment

AU - Hahn, Jan

AU - Fromm, Michael

AU - AL Halabi, Fedaa

AU - Besdo, Silke

AU - Lubatschowski, Holger

AU - Ripken, Tammo

AU - Krüger, Alexander

PY - 2015/8/11

Y1 - 2015/8/11

N2 - Purpose: According to Helmholtz, accommodation is based on the flexibility of the crystalline lens, which decreases with age, causing presbyopia. With femtosecond (fs)-lentotomy treatment, it is possible to restore the flexibility of presbyopic lenses. The efficiency of the treatment can be systematically evaluated using the finite element method based on experimental data. The purpose of this study was to quantify the shape change of ex vivo lenses in different accommodation states according to the fs-lentotomy treatment.Methods: Five lenses with ciliary body excised from ex vivo porcine eyes (age: approximately 6 months, exact age unknown) were stretched in an accommodation device before and after laser treatment. Depending on the accommodation state, the lens shape, reconstructed from lens thickness, diameter, and anterior and posterior curvature, was measured using optical coherence tomography (OCT). The complete lens shape was parameterized and each measured parameter was compared to the results of a control group (n = 5, age: approximately 6 months, exact age unknown) without treatment.Results: The amplitudes of the parameters thickness (+140%), diameter (+54%), and anterior radius of curvature (+57%) significantly increased after treatment (P < 0.05), and showed no significant change for the control group. By contrast, the amplitude of the posterior radius of curvature showed no change after treatment (P > 0.05).Conclusions: Measurement of the lens shape in different accommodation states was successful and showed significant changes after the treatment. The resulting data will be utilized as input for a finite element model to systematically evaluate the effect of fs-lentotomy treatment in future work.

AB - Purpose: According to Helmholtz, accommodation is based on the flexibility of the crystalline lens, which decreases with age, causing presbyopia. With femtosecond (fs)-lentotomy treatment, it is possible to restore the flexibility of presbyopic lenses. The efficiency of the treatment can be systematically evaluated using the finite element method based on experimental data. The purpose of this study was to quantify the shape change of ex vivo lenses in different accommodation states according to the fs-lentotomy treatment.Methods: Five lenses with ciliary body excised from ex vivo porcine eyes (age: approximately 6 months, exact age unknown) were stretched in an accommodation device before and after laser treatment. Depending on the accommodation state, the lens shape, reconstructed from lens thickness, diameter, and anterior and posterior curvature, was measured using optical coherence tomography (OCT). The complete lens shape was parameterized and each measured parameter was compared to the results of a control group (n = 5, age: approximately 6 months, exact age unknown) without treatment.Results: The amplitudes of the parameters thickness (+140%), diameter (+54%), and anterior radius of curvature (+57%) significantly increased after treatment (P < 0.05), and showed no significant change for the control group. By contrast, the amplitude of the posterior radius of curvature showed no change after treatment (P > 0.05).Conclusions: Measurement of the lens shape in different accommodation states was successful and showed significant changes after the treatment. The resulting data will be utilized as input for a finite element model to systematically evaluate the effect of fs-lentotomy treatment in future work.

UR - http://dx.doi.org/10.1167/iovs.14-16185

U2 - 10.1167/iovs.14-16185

DO - 10.1167/iovs.14-16185

M3 - SCORING: Journal article

VL - 56

JO - INVEST OPHTH VIS SCI

JF - INVEST OPHTH VIS SCI

SN - 0146-0404

ER -