Preoperative measurement vs intraoperative aberrometry for the selection of intraocular lens sphere power in normal eyes

Abstract

PurposeThis study aimed to assess the value of intraoperative aberrometry (IA) in determining the intraocular lens (IOL) sphere power in eyes with no previous ocular surgery.Patients and methodsWe conducted a retrospective review of patients who underwent uncomplicated cataract surgery where standard preoperative (Preop) measurements and IA were performed. Calculated IOL sphere powers and postoperative refractions, both actual and theoretical, were compared based on the measurement method and lens type; lens types included multifocal, toric and aspheric single-vision non-toric IOLs.ResultsA total of 160 eyes of 112 patients were analyzed. The Preop lens power calculated was the same as the IA lens power 46% of the time, though this percentage was lower for multifocal IOLs. Across all lens types, there was a statistically significant bias (chi-square test, P<0.01) toward the IA method suggesting a lower powered lens. Actual postoperative refractive errors were not statistically significantly different when categorized by measurement method. Calculated errors by measurement method showed no statistically significant differences in expected outcomes. There were 63 cases where the Preop calculation and the intraoperative aberrometer calculation differed by 0.5 D. In 56% (35/63) of these cases, the IA result was a better option, and in 44% (28/63) of cases, the Preop calculation was better; this was not statistically significantly different from random expectation (50/50, P=0.53). In the three cases where calculated powers differed by 1.5 D, there appeared to be a positive effect of adjusting the Preop power toward the IA power.ConclusionThe use of IA for the determination of sphere power in eyes with no previous ocular surgery does not appear to improve overall expected clinical outcomes, but it may be helpful in cases where the difference between IA and Preop calculations is high.

Comparison of IOL Power Calculated by Preoperative Biometry versus Intraoperative Wavefront Aberrometry in Thai Cataract Patients.

“…We also found that the ORA result is inconcordance with IOL master ® 700 which is the current gold standard for modern optical biometry devices. 19 20 Fisher et al 21 , reported 39% of 44 post-lasik eyes that had the same suggested IOL power from the IOL master and the ORA. The limited number of subjects could have made our results lower than the others.…”

Clinical Evaluation of Toric Intraocular Lens Implantation Based on iTrace Wavefront Keratometric Astigmatism

“…Factors in uencing residual refractive astigmatism after cataract surgery with toric IOLs include accurate preoperative corneal astigmatism measurements, variability in the magnitude and direc tion of corneal incision SIA, the effects of dif ferent toric calculators, the rotational stability of different toric IOLs [8], and reported lens tilt [9]. Several diagnostic devices based on different technologies are available to measure preoperative corneal power and astigmatism, including manual and automated keratometers; Placidobased corneal, point-source color light emitting diode, Scheimp ug image-based, and scanning-slit corneal topographers; low-coherence re ectometers; and intraoperative aberrometers [10][11][12][13]. However, none of these methods are currently considered the gold standard.…”

Clinical Evaluation of Toric Intraocular Lens Implantation Based on iTrace Wavefront Keratometric Astigmatism

“…IOLs [8], and reported lens tilt [9]. Several diagnostic devices based on different technologies are available to measure preoperative corneal power and astigmatism, including manual and automated keratometers; Placido-based corneal, point-source color light emitting diode, Scheimpflug imagebased, and scanning-slit corneal topographers; low-coherence reflectometers; and intraoperative aberrometers [10][11][12][13]. However, none of these methods are currently considered the gold standard.…”