Abstract
Abstract: :
Purpose: To compare the refractive data from manifest refraction (MR), cycloplegic refraction (CR) and the Hartman-Shack wavefront analyzer. Methods: 40 eyes of 40 patients were compared for accuracy between MR, CR and wavefront analysis with the Zywave® (Bausch & Lomb) aberrometer (ZR). The wavefront data was obtained after cycloplegia and set for pupil sizes of 3.5mm (ZR3.5) and 6mm (ZR6). Statistical analysis was performed using T student test and the Pearce correlation coefficient. Results: The mean age was 39 years (Range 20-66; SD: 10.4), mean spherical equivalent (SE) –2.80 (Range –9.50 to +5.25; SD: 3.03), and mean astigmatism 0.78 (range 0 to 3.00. SD: 0.75). There was no statistically significant difference between CR SE, sphere and ZR3.5 (p= 0.09 and 0.53, correlation coefficient: 0.97 and 0.96). When the CR SE and sphere were compared against the ZR6 a statistically significant difference was found (P: <0.01) with a myopic shift evident for the latter (mean difference: 0.68 CI: 0.47 to 0.89) The MR Sphere and SE were also significantly different when compared with both the ZR3.5 and ZR6 (<0.01). Conclusions: The refractions performed with the Zywave® aberrometer set at 3.5mm showed a high correlation with the cycloplegic refraction
Keywords: refractive surgery • refractive surgery: optical quality • refraction