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Low_resolution_Thesis_CDD_221009_public - Visual Optics and ...

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ANTERIOR AND POSTERIOR CORNEAL ELEVATION MAPS AFTER REFRACTIVE SURGERY<br />

change 1 week <strong>and</strong> 1 month after surgery. Figure 7.3(C), shows the measured<br />

longitudinal displacements of the apex of the posterior corneal surface. These<br />

displacements were less than 35 m in individual eyes, <strong>and</strong> on average they were not<br />

statistically significant at any time point.<br />

Fig. 7.4: Individual changes in post-operative radii of curvature of the posterior<br />

corneal radius relative to the pre-operative value. Each panel shows data for one<br />

individual patient. Solid line: Right eye. Dashed line: Left eye. Filled dots indicate<br />

statistically significant changes ( = 0.017) (A-F) Patients whose two eyes were<br />

measured the three times postoperatively (except for patient B’s left eye, with less<br />

than three valid topographies 1-month post-operatively). (G-L) Controls whose two<br />

eyes were measured the three times.<br />

Figure 7.4 (A-F) shows individual changes in radius of curvature versus time, for<br />

the 6 patients whose two eyes which had the the three measurements (1 day, 1 week<br />

<strong>and</strong> 1 month). Each panel shows data on a single subject. Solid lines represent right<br />

eyes <strong>and</strong> dotted lines left eyes. Points marked with a filled dot mean a statistically<br />

significant change with respect to the pre-operative measurement, while empty circles<br />

mean that the change is not statistically significant (2-sample unpaired Student’s t test<br />

between the repeated preoperative <strong>and</strong> postoperative measurements, =0.05/3). There<br />

is no systematic trend followed by all patients, but note that statistically significant<br />

changes are frequent. Four eyes show a statistically significant <strong>and</strong> sustained decrease<br />

in posterior radius after surgery (Fig. 7.4 (A,B,E)). On the other h<strong>and</strong>, another two<br />

eyes show the opposite: systematic <strong>and</strong> sustained increase in radius (Fig. 7.4 (D, F)).<br />

Most patients show a non-systematic behavior.<br />

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