Intraocular Lens Power Selection and Positioning With and Without Intraoperative Aberrometry

Hatch, Kathryn M; Woodcock, Emily C; Talamo, Jonathan H.

doi:10.3928/1081597x-20150319-03

Cited by 60 publications

(47 citation statements)

References 13 publications

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“…We also did not use intraoperative aberrometry 19 or a ray-tracing method, such as the one suggested by Hoffmann et al 14 Additional studies comparing the Abulafia-Koch formula adjustments and the Barrett IOL calculator to intraoperative aberrometry and to devices that directly measure the net corneal astigmatism by a ray-tracing approach are warranted. An additional limitation of our study is that we validated the Abulafia-Koch formula using IOLMaster measurements.…”

Section: Methods Of Calculationmentioning

confidence: 99%

“…However, several studies recently reported that methods of calculation that account for posterior corneal astigmatism might be more appropriate for toric IOL calculations. Those methods apply nomograms, 13 coefficients of adjustment, 6 direct measurements of the posterior cornea, 10,18 a ray-tracing approach using combined keratometry and tomography data, 14 intraoperative aberrometry, 19 and mathematic models. 12 The purpose of this study was to describe a new regression formula that can calculate the estimated total corneal astigmatism using standard keratometry (K) measurements and to compare the error in the predicted residual astigmatism of 2 representative toric IOL calculators with and without the use of the new formula.…”

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confidence: 99%

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New regression formula for toric intraocular lens calculations

Abulafia¹,

Koch²,

Wang³

et al. 2016

Journal of Cataract and Refractive Surgery

101

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Dr. Abulafia received a speaker's fee from Haag-Streit AG. Dr. Barrett has licensed the Barrett Toric Calculator to Haag-Streit AG. Dr. Koch is a consultant to Alcon Laboratories, Inc., Abbott Medical Optics, Inc., and Revision Optics, Inc. Dr. Hill is a paid consultant to Haag-Streit AG and Alcon Laboratories, Inc. None of the other authors has a financial or proprietary interest in any material or method mentioned.

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Section: Methods Of Calculationmentioning

confidence: 99%

mentioning

confidence: 99%

New regression formula for toric intraocular lens calculations

Abulafia¹,

Koch²,

Wang³

et al. 2016

Journal of Cataract and Refractive Surgery

101

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“…Potential causes of this include patient factors (such as eyelid squeezing, eye motion, healing), surgical equipment or devices (such as the eyelid speculum or use of certain ophthalmic viscosurgical devices) and/or intraoperative manipulation (such as stromal hydration); these factors can change intraocular pressure and axial length, corneal thickness and the refractive index of the anterior chamber 9–11. Studies suggest that these operative variables may be adequately controlled, especially with increased surgeon experience using IA 3,4. A more fundamental concern is the lack of measurement of the expected lens position (ELP), which is a significant factor affecting the power of an IOL.…”

Section: Introductionmentioning

confidence: 99%

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

Davison¹,

Potvin²

2017

OPTH

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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.

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“…The method of determining the steep axis at the time of IOL implantation is the key to successful implantation of a toric IOL. The recently developed image guided system to overlay the steep axis under the microscope and intraoperative aberrometry are expected to improve the accuracy of IOL alignment [20].…”

Section: Discussionmentioning

confidence: 99%

Comparison between Toric and Non-Toric Intraocular Lenses in Patients with Corneal Astigmatism: A One-Year Multicenter Study

Miyajima¹,

Inoue²

2016

J Clin Exp Ophthalmol

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Objective: To compare the clinical results obtained with a toric intraocular lens (IOL) and non-toric IOL in eyes with corneal astigmatism.Methods: This multicenter retrospective study included eyes with corneal astigmatism ranging from 0.75 diopter (D) to 3.00 D that were implanted with a toric IOL and a non-toric IOL. Non-toric IOLs were implanted before toric IOLs were approved, and the eyes were divided into three groups (T3, T4, or T5) depending on the preoperative degree of corneal astigmatism. Residual refractive cylinder, uncorrected distance visual acuity (UDVA), and contrast sensitivity were compared more than 1 year after implantation. Results:The toric group included 149 eyes (mean patient age, 73.7 ± 7.9 years standard deviation, SD) and the non-toric group included 121 eyes (mean patient age, 76.2 ± 5.9 years). One year postoperatively, the respective residual refractive cylinder values and ± SD of the toric/non-toric groups were -0.61 ± 0.43/-1.45 ± 0.98 D (all eyes), -0.58 ± 0.42/-1.14 ± 0.70 D (T3), -0.59 ± 0.42/-1.63 ± 0.99 D (T4), and -0.67 ± 0.47/-2.18 ± 1.27 D (T5). The respective logarithm of the minimum angle of resolution UDVA values was 0.00 ± 0.12/0.16 ± 0.20 (all eyes), 0.00 ± 0.11/0.13 ± 0.18 (T3), 0.00 ± 0.13/0.25 ± 0.23 (T4), and 0.00 ± 0.11/0.17 ± 0.16 (T5). The toric group had better cylinder and UDVA outcome values; the difference between the groups reached significance (p<0.0001). In the toric group, the IOL rotation after implantation was 4.3 ± 4.0 degrees. Conclusion:Toric IOLs reduced the residual refractive cylinder in cases with corneal astigmatism between 0.75 and 3.00 D, and this effect was similar among different toric models. Toric IOLs are useful to improve the UDVA after cataract surgery.

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Intraocular Lens Power Selection and Positioning With and Without Intraoperative Aberrometry

Abstract: Patients undergoing cataract extraction with toric IOL placement aided by intraoperative aberrometry were 2.4 times more likely to have less than 0.50 D of RRA compared to standard methods.

Cited by 60 publications

References 13 publications

New regression formula for toric intraocular lens calculations

New regression formula for toric intraocular lens calculations

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

Comparison between Toric and Non-Toric Intraocular Lenses in Patients with Corneal Astigmatism: A One-Year Multicenter Study

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