Comparison Of Refractive Assessment By Pyramidal Wavefront Abberometry, Subjective Refraction And Cycloplegic Refraction By Expert Refractionist
Published 2023 - 41st Congress of the ESCRS
Reference: PO1023 | Type: Free paper | DOI: 10.82333/pm4g-sh87
Authors: Jerry Tan* 1 , Samuel Arba Mosquera 2 , Bee Yong Andrew Tan 3 , Bee Tat Nicholas Tan 4 , Francesco Versaci 5
1Jerry Tan Eye Surgery,Singapore,Singapore, 2SCHWIND eye-tech-solutions GmbH,Kleinostheim,Germany, 3Ophthalmology,Tan Tock Seng Hospital,Singapore,Singapore, 4Ophthalmology,Changi General Hospital,Singapore,Singapore, 5Costruzione Strumenti Oftalmici,Firenze ,Italy
Purpose
To compare refractive assessment results obtained with a pyramidal aberrometer, manual subjective refraction and cycloplegic refraction by an expert refractionist in a pre-refractive surgery assessment population with optimal visual potential.
Setting
Private practice, Jerry Tan Eye Surgery, Singapore
Design: Retrospective study.
Methods
140 adults (262 eyes) aged 20 - 48 years with visual acuity of 6/6 or better, no media opacity and no known corneal or retinal abnormalities were consecutively measured for pre-refractive surgery. Refractive error in each eye of every patient was assessed by 3 methods: manual subjective refraction, pyramidal aberrometry (SCHWIND PERAMIS Topographer and Aberrometer) determined for fixed 4mm diameter from larger ocular wavefront scans, and cycloplegic refraction by an expert refractionist (main author). The order of testing was randomized. 2 optometrists performed manual subjective refraction while cycloplegic refraction was performed by main author. Refractive measurements were compared with the Bland-Altman analysis.
Results
Bland-Altman analysis of spherical defocus identified mean differences (95% limits agreement) of -0.04 ± 0.26 D (0.52 D LoA) for manifest refraction (MRx) versus cycloplegic refraction (CRx), +0.42 ± 0.39 D (0.77 D LoA) for manifest refraction versus pyramidal aberrometer (P-Rx) refraction, -0.34 ± 0.29 D (0.57 D LoA) for P-Rx versus pyramidal aberrometer cycloplegic (P-CRx) refraction and +0.15 ± 0.31 D (0.60 D LoA) for CRx versus P-CRx. Additionally, a mean difference in of +0.08 ± 0.36 (0.71 D LoA) for MRx – P-CRx and +0.50 ± 0.39 D (0.77 D LoA) for CRx – P-Rx has been found. Magnitude of the cylinder and axis of astigmatism were also analyzed similarly.
Conclusions
A very low residual accommodation (~0,2D) during Rx in this series. Pyramidal Wavefront Sensor exhibits ~0,3 Dioptre of instrumental myopia. Cycloplegia or latent Accommodation do not seem to affect subjective or objective refractive astigmatism and axis. Objective CRx can be used instead of subjective Rx. Improving the accuracy and precision of (manifest) refraction preoperatively seems to be the key to increase the predictability of surgery and decrease the enhancement rate.