Optical Biometry before and after Excimer Laser Epithelial Keratomileusis (LASEK) for Myopia

Abstract

Purpose In order to select the correct intraocular lens (IOL) for implantation, it is important to measure the eye length (biometry). The IOL Master from Zeiss-Humphry is frequently used for such measurements. Because this instrument employs an optical method, any irregularities on the corneal surface or any disturbances in corneal transparency could lead to mistakes in the measurements. The aim of this study was to determine whether eye length measurements obtained at the University Eye Clinic Regensburg, Germany with the IOL Master before and after excimer laser epithelial keratomileusis (LASEK) show any changes. Methods Axial length was measured on 20 myopic eyes (–2.75 to –8.00 diopters) before and one month after LASEK using the IOL Master. Results The mean pre-operative eye length was 25.46 mm (SD±1.03) and the postoperative mean length was 25.38 mm (SD±0.99). There was a strong correlation between the pre- and post-operative eye lengths (Pearson correlation coefficient 0.998). Conclusions Although LASEK can lead to increased light scattering due to irregularities of the corneal surface and changes in corneal transparency, there is no difference in biometry pre- and post-operatively.

Axial eye length measurements pre- and post- laser-assisted in situ keratomileusis using the IOL Master: a pilot study

“…The first study published regarding the measurement of the axial eye length before and after an excimer laser procedure was from von Mohrenfels et al6 They measured the axial eye length before and after laser-assisted sub-epithelial keratectomy (LASEK) with the IOL Master and they did not find a statistically significant difference before and 1 month after the refractive surgery. Nonetheless, Rosa et al7 in a later publication did not agree with their conclusions.…”

Refractive Stability and Ocular Biometric Changes After Customized LASEK for Correction of Myopia; 8 Years Follow up

“…Advancement in ablation pro les and modalities of treatments have drawn renewed interest in detecting the correlation between corneal changes and ocular biometric parameters with refractive stability but still discrepancies exist . [5][6][7] In spite of several studies that evaluated short-term changes in ACD and AL 8,9 , there is still uncertainty in terms of long-term changes in ocular biometry parameters using similar measurement methods pre and post myopic excimer laser surface ablation. In current study we report long-term visual and refractive outcomes and ocular changes in biometric parameters following LASEK for correction of low to moderate myopia.…”

Intraocular lens power calculation after corneal refractive surgery

“…Assuming accurate biometry, axial length measurements are unlikely to contribute significantly to IOL power errors after corneal refractive surgery. Two studies analyzing axial length before and after RK and excimer keratectomy found no significant differences 1819…”