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Scientific News

Browse through the latest scientific news related to IOL power calculation.

Accuracy of IOL Calculation Formulas

Researchers evaluated the accuracy of IOL calculation formulas in the prediction of postoperative refraction using a single optical biometry device. They compared the performance of each formula with respect to the error in predicted spherical equivalent and analyzed the effect of applying the Wang–Koch (WK) adjustment for eyes with axial length >25.0 mm on 4 of the formulas. The Barrett Universal II formula had the lowest prediction error for the 2 IOL models studied.

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Clinical Outcomes after Bilateral Implantation of the AT LISA Tri Toric 939MP IOL in Eyes with Preexisting Corneal Astigmatism

In eyes with moderate to high levels of corneal astigmatism (≥1.00 D) the implantation of the AT LISA tri toric 939MP provides an effective restoration of the distance, intermediate, and near vision after cataract surgery. This visual restoration is achieved with good levels of photopic and mesopic contrast sensitivity and a low incidence of photic phenomena (glare and halos).
Read the full free text of this study in the Journal of Refractive Surgery.

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Comparison of Toric Lens Calculation with AL-Scan and IOLMaster 500

Different optical biometers sometimes take keratometry readings in different zones. A study with 81 patients was conducted to compare the IOLMaster 500 and a new AL-Scan biometer in terms of toric IOL selection. Corneal astigmatism measurements were similar and the process of lens selection did not alter at all. Read this abstract on PubMed to find out more.

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IOL Power Calculation after Radial Keratotomy

IOL power calculation in patients who previously underwent radial keratotomy (RK) is a special challenge. In a retrospective case series of 20 former RK patients (26 eyes) the final spherical equivalent (SE) refractions after routine cataract surgery were compared. For IOL power calculation the Haigis formula with keratometry values from three different devices was used. Go to the abstract on PubMed to find out more.

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High Levels of Visual Quality and Patient Satisfaction after Bilateral Implantation of AT LISA Tri 839MP IOL

In a prospective nonrandomized study (76 eyes with a preoperative corneal astigmatism of ≤1.25D) the visual, refractive, and contrast sensitivity outcomes are evaluated, as well as the incidence of photic phenomena and patient satisfaction. The results confirm that the AT LISA tri 839MP is able to provide an effective restoration of visual function for far, intermediate, and near distances, offering high levels of visual quality and patient satisfaction. Read the full study published in the Journal of Ophthalmology to find out more.

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Lens Power Calculation Formulas in Small Eyes

In a study the accuracy of the Haigis, Hoffer Q, Holladay 1, Holladay 2, SRK/T, and SRK-II IOL power prediction formulas was investigated in small adult eyes. While none of the latest-generation formulas significantly outperformed the others, the SRK formulas yielded less accurate results. Go to the abstract on PubMed to find out more.

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Comparison of three toric IOL calculators to predict residual astigmatism after IOL implantation

In a study on 99 eyes the accuracy of the Alcon, Holladay, and Barrett toric calculators was evaluated using keratometry measurements of the IOLMaster 500 and the Pentacam (Oculus). The Barrett toric calculator using the IOLMaster measurements had the lowest median absolute error and centroid error in predicted residual astigmatism and achieved the most accurate results. Go to the abstract on PubMed to find out more.

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