Abstract
Purpose:
To assess the refractive predictability of an intraoperative aberrometer, the Optiwave Refractive Analysis (ORA) system, by determining the difference in refraction between intraoperative and postoperative measurements.
Methods:
A study was conducted on 53 consecutive eyes that have undergone cataract extraction for which ORA intraoperative and postoperative refractions were obtained. All surgeries were performed by one surgeon (MW). The average of the last three ORA intraoperative refraction measurements was determined. We defined “Settling Factor” (SF) as the difference between intraoperative and postoperative measurements. For each patient, we determined SF for spherical equivalent (SE) by subtracting the intraoperative SE from the postoperative SE at 1-month and 3-months. Arithmetic and absolute averages of SF for SE for the entire group was calculated. SF for SE was then stratified according to virgin corneas or post-refractive surgery corneas, and also by the IOL type, Crystalens, Restor, Tecnis MF and EC monofocal IOL. With regard to astigmatism, we determined vector difference between intraoperative and postoperative cylinder and axis in each patient using double-angle plot. The average SF for the magnitude of cylinder for the entire group was calculated.
Results:
The arithmetic average SF for SE for the entire group (n=53) was 0.11 D ± 0.81 D at 1 month and 0.12 D ± 0.81D at 3 months,values for virgin eyes (n=47) were 0.07D ± 0.82D at 1 month and 0.10D ± 0.70D at 3 months, and values for post-refractive surgery eyes (n=6) were 0.47D ± 0.65D at 1 month and 0.10D ± 0.70D at 3 months. With regard to IOL type, SF for SE for EC monofocal (n=17) were 0.10 ± 0.72 at 1 month and 0.00D ±0.82D at 3 months, for Crystalens (n=7) were-0.51D ± 1.03D at 1 month and 0.10±0.70 at 3 months, for Restor (n=5) -0.44 ± 0.62 at 1 month and -0.24±0.57 at 3 month, and for Tecnis MF (n=24) were 0.47D ± 0.65D at 1 month and 0.39D ± 0.77D at 3 months.. With regard to astigmatism, the average SF for magnitude of cylinder for the entire group (n=53) were 0.60D ± 0.39 D at 1 month and 0.63D± 0.41 D at 3 months.
Conclusions:
Optiwave Refractive Analysis (ORA) system appears to have a reasonably good predictability in refraction, demonstrating a small average difference in spherical equivalent and in magnitude of cylinder between intraoperative and postoperative measurements.
Keywords: 445 cataract •
428 astigmatism •
764 vitreous substitutes