ABSTRACT
Objective To study the changes of posterior corneal elevation with one-year follow-up by using Allegro Oculyzer anterior segment diagnostic system in patients who had undergone laser in situ keratomileusis with femtosecond laser (FS-LASIK) for myopia. Methods Ninety eyes of forty-five patients who had undergone FS-LASIK for myopia were included in our study . The spherical equivalent of ametropia was-10.63D to -1.63D. The preoperative and postoperative corneal tomography (including 1, 3, 6 and 12 month after operation ) were collected by Allegro Oculyzer in the posterior corneal elevation and the thickness at central corneal thinnest point of each eye were measured , and the differences of the posterior corneal elevation were calculated. The data were analyzed with ANOVA and Pearson correlation analysis. Results There were no statistically significant differences in the changes of posterior corneal elevation from the preoperative time to the any postoperative follow-up time (F = 1.50, P > 0.05). There were no statistically significant changes of the posterior corneal elevation from the 1st month to 12th month postoperatively (F = 1.47, P > 0.05). There were statistically significant differences in the changes of thickness at central corneal thinnest point from the preoperative to the 12th month postoperative (F = 369.10, P 0.05). Conclusion After strictly followed surgical indications in FS-LASIK, the posterior corneal elevation can keep good stability and has no significant change. Thickness of central cornea thinnest point increases gradually and tends to stablity at the 3th months after surgery.
ABSTRACT
PURPOSE: To evaluate the association with corneal thickness and corneal thinnest point using Orbscan topography. METHODS: One hundred and four eyes of the 52 normal subjects who were investigated using an Orbscan topography, were devided into following two groups ; one was inferonasal group which has the thinnest point in inferonasal quadrant(23 eyes, 22.1%), and the other was inferotemporal group which has the thinnest point in inferotemporal quadrant. (79 eyes, 76%) Among them, age-matched 30 eyes were randomly selected. The corneal thickness of two groups were measured at eight meridian of each point distant 1.0, 1.5, 2.0, 2.5, 3.0mm from corneal center. The thickest point and the thinnest point of cornea in two groups were compared and analysed. RESULTS: The thickest point of cornea in two groups was located in the superior portion. The thinnest quadrant was located in the inferonasal portion for inferonasal group and in the inferotemporal portion for inferotemporal group. CONCLUSIONS: The quadrant where the thinnest quadrant existed had the thinnest corneal thickness in comparing with any other quadrant.