Purpose: To assess the corneal keratometric values obtained using the VERION image-guided surgery system and other devices. Methods: This study evaluated the right eyes of 115 cataract patients before intraocular lens (IOL) implantation through consecutive tests using 5 devices: VERION Reference Unit, Placido-based corneal topography (OPD-Scan III), monochromatic light-emitting diodes (LenStar LS900 and AL-Scan), and rotary prism technology (auto kerato-refractometer KR-8800). Analyzed parameters were corneal steep and flat keratometric values (Ks and Kf) and corneal astigmatism and axis. These parameters were evaluated using the one-sample two-tailed t-test and the 95% limits of agreement (95% LOAs) between the devices. Results: The mean corneal cylinder value measurements were −0.97±0.63 D, −0.88± 0.60 D, −0.90±0.69 D, −0.90±0.67 D, and −0.83±0.60 D with VERION, LenStar, AL-Scan (2.4 mm), OPD III, and KR-8800, respectively. Only KR-8800 showed a significant difference from VERION in the corneal cylinder value (P<0.05). The mean differences in the Kf and Ks of VERION compared to those of OPD III were 0.18±0.45 D and 0.17±0.38 D (P<0.05), respectively. The 95% LOAs of Bland–Altman analysis for the corneal astigmatism axis of the VERION with LenStar, AL-Scan (2.4 mm), OPD III, and KR-8800 were −26.25° to 58.71°, −20.61° to 47.44°, −25.03° to 58.98°, and −27.85° to 65.17°, respectively. Conclusion: None of the VERION parameters were significantly different from those of AL-Scan and LenStar. AL-Scan (2.4 mm zone) was especially similar to VERION. Wide LOAs are potential contributors to axis error in patients with toric IOL implants.
Lin, H. Y., Chen, H. Y., Fam, H. B., Chuang, Y. J., Yeoh, R., & Lin, P. J. (2017). Comparison of corneal power obtained from verion image-guided surgery system and four other devices. Clinical Ophthalmology, 11, 1291–1299. https://doi.org/10.2147/OPTH.S137878