Comparison Of Corneal Power And Central Corneal Thickness Measured By Four Different Optical Coherence Tomography Devices In Eyes After Myopic Laser Keratorefractive Surgery.

To compare total power of the cornea (TCP) and central corneal thickness (CCT) values of the corneas after myopic laser keratorefractive surgery obtained from four different devices using optical coherence tomography (OCT).

Oftalmika Eye Hospital, Bydgoszcz, Poland

Division of Ophthalmology and Optometry, Department of Ophthalmology, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Poland

This retrospective study comprises 48 eyes that previously underwent myopic laser keratorefractive surgery. Mean preoperative spherical equivalent was -2,46 ± 3,88D. Four to six months after the surgery, the corneal optical power based on both anterior and posterior curvatures were measured in an automatic mode with a biometer - IOLMaster 700 (Carl Zeiss Meditec) and 3 different anterior segment optical coherence tomographers (AS-OCT): ANTERION (Heidelberg Engineering), AvantiRTVue XR (Optovue), and MS-39 AS-OCT (CSO).

The average TCP for IOLMaster 700, ANTERION, AvantiRTVue XR, and MS-39 AS-OCT was 41.5 ± 3.95 D, 40.88 ± 4,11 D, 40.59 ± 4.15 D and 41.07 ± 4.11 D, respectively. Among the 4 OCT devices, TCP values presented strong positive correlation between results from different devices. Correlation coefficients for TCP were between 0.995 and 0.999. However, differences between individual devices were statistically significant, except for AvantiRTVue XR/ANTERION and ANTERION/MS-39. The CCT for IOLMaster 700, ANTERION, AvantiRTVue XR, IOLMaster 700, and MS-39 AS-OCT was 481.19 ± 65.69 µm, 481.33 ± 63.16 µm, 477.81 ± 60.53 µm and 480.5 ± 63.95 µm, respectively. Correlation coefficients for CCT were within a range of 0.994 and 0.999.

Although correlations of the measurements of TCP obtained with 4 different OCT instruments were very high, the differences between mean values indicate that they could not be used interchangeably in eyes after myopic keratorefractive surgery. A satisfactory agreement between the instruments was observed for CCT.