The Pentacam® AXL Wave provides a reliable wavefront-based objective refraction when compared to manifest subjective refraction: A prospective study

Abstract

Purpose: Accurate refraction is arguably the most important parameter for a successful laser vision correction surgery and is based on a combination of manifest and cycloplegic refraction. Wavefront-based objective refraction may be useful in the evaluation of patients. So far, the reliability of objective refraction as measured using the Pentacam ® AXL Wave has not been published in the literature. Methods: This was a prospective study including a total of 168 eyes belonging to 84 young non-presbyopic patients evaluated for refractive surgery. Pentacam ® AXL Wave full sequence was taken for all patients. Then, a clinician who was unaware of the objective refraction results performed a full physical examination, including manifest refraction starting from an autorefractometer value. All refraction values were transferred to astigmatic power vectors as per the Thibos method. Reliability of the different vectors and a unifying blur value were compared using Spearman correlation, Bland–Altman plot, and intraclass correlation coefficient. Results: The mean age was 28.8 ± 5.4 years, with a female preponderance (60.7%). The correlation between both eyes was high. The difference in M vector between subjective and objective refraction was 0.16 D, while the difference was 0.04 and 0.01 D for the J 0 and J 45 vectors, respectively. Paired samples Student t was non-significant for all comparisons. Spearman rho correlations were high (0.666–0.924, all P < 0.001). Intraclass correlation coefficients were also high (0.890–0.966). Bland–Altman plots did not demonstrate any systematic errors. Conclusion: Wavefront-based refractive refraction obtained using the Pentacam ® AXL Wave is highly agreeable and correlated with measurements obtained by manifest subjective refraction.

FIAT: A Device for Objective, Optical Measures of Accommodation in Phakic and Pseudophakic Eyes

“…Improved insights into the relationships between wave aberration and perceived best focus were made possible through accurate measurements of the wave aberrations of the eye using wavefront sensors. 12 Today, ophthalmic wavefront sensor systems are commercially available and appear to optimize image-sharpness metrics using undisclosed algorithms to provide objective measures of the eye's refractive prescription (Visionix, Luneau Technology, France; Pentacam AXL Wave, Oculus, Arlington, WA, USA 13 ; Wavedyn, Wavefront Dynamics, Albuquerque, NM, USA). The use of wavefront sensors to offer objective measures of accommodation is less common (commercial devices: Osiris, CSO Ophthalmic, Scandicci, Italy 14 ; COAS-HD, Wavefront Sciences [no longer commercially available] 15 ; iTrace, Tracey Technologies, Houston, TX, USA 16 ; and several reported research devices 17 – 20 ).…”