<p>Clinically relevant differences in the selection of toric intraocular lens power in normal eyes: preoperative measurement vs intraoperative aberrometry</p>

Abstract

Purpose: To assess the value of intraoperative aberrometry (IA) in determining toric intraocular lens (IOL) power in eyes with no previous ocular surgery. Patients and methods: This was a retrospective data review at one US clinical site of eyes that underwent uncomplicated cataract surgery with toric IOL implantation where standard preoperative and IA measurements were available. Calculated IOL sphere and cylinder powers and orientation were compared based on the measurement method and the postoperative refraction, using both actual and simulated (back-calculated) results. Comparisons were between the surgeon’s preoperative calculations, IA measurements, the actual IOL implanted and results from the Barrett toric calculator. Results: There was no significant difference ( p >0.7) in the number of eyes expected to have, or having, a spherical equivalent refraction within 0.50D of the target between Actual (92%), IA (93%) or Preoperative calculation results (86%). The percentage of eyes with expected residual refractive astigmatism ≤0.50D was significantly higher for the IA vs Preoperative calculations (75% vs 53%, p <0.01). There was no significant difference in expected results between the Actual, IA and Barrett toric calculations ( p >0.65). Conclusion: Modern IOL calculations for sphere produced results comparable to those achieved with IA. The value of IA in determining IOL cylinder power and orientation was more evident when comparing expected results between IA and a preoperative method based on measured total corneal astigmatism than when comparing to expected results from the Barrett toric calculator.

Clinical evaluation of toric intraocular lens implantation based on iTrace wavefront keratometric astigmatism

“…Keratometers, corneal topographers, anterior segment tomographers, and intraoperative aberrometers can each provide corneal measurements necessary to accurately predict the ideal IOL cylinder power and alignment meridian to correct astigmatism during cataract surgery [ 6 ]. Since each device has its own characteristics, measurements obtained from different devices may not be comparable due to different refractive indices or measurement areas being used.…”

Intraoperative aberrometry: an update on applications and outcomes

“…Numerous studies have shown that cataract surgery with intraoperative aberrometry achieves low postoperative residual astigmatism [5,14,37,52,[62][63][64][65][66][67][68], including multiple studies in which intraoperative aberrometry was shown to achieve lower postoperative residual astigmatism than preoperative measurements [5,14,52,62,67,68] and studies in which intraoperative aberrometry achieved a larger proportion of patients with residual astigmatism less than 0.5D [67,68]. Of note, several studies using the Barrett toric calculator (which incorporates posterior corneal astigmatism) have not shown lower postop residual astigmatism in intraoperative aberrometry relative to preoperative calculations [37,69,70]; however, other studies utilizing the Barrett toric calculator have shown lower postop residual astigmatism in intraoperative aberrometry [67,68]. One study also found that computer-assisted registration utilizing the Zeiss Callisto Eye achieved lower postop residual astigmatism than intraoperative aberrometry [61].…”

“…Moreover, in studies with broad cohorts, overall outcomes are generally not reported, and instead the focus is on subsets of patients [20 ▪▪ ,28 ▪ ]. In contrast, there are numerous studies that instead focus on either routine/typical non-post-refractive surgery cases alone [6,9,10 ▪ ,11,14,30–32,33 ▪ ,34–38] or on subsets of atypical patients [29,39–52]. This trend in publications may be at least in part a reflection that in the real world, many cataract surgeons utilize intraoperative aberrometry selectively rather than broadly.…”

Astigmatism Management with Astigmatism-Correcting Intraocular Lens Using Two Toric Calculators – A Comparative Case Series

“…1 Nevertheless, they require additional effort, including preoperative measurement, planning, and modifications in intraoperative techniques. [2][3][4][5][6][7] Previous studies have reported good visual and refractive outcomes, which are an important part of the standard of care for astigmatism correction with cataract surgery, especially in higher degrees of astigmatism. [8][9][10][11][12] This procedure is also ideal for patients with regular astigmatism who hope to reduce their dependence on glasses for distance vision.…”