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Evaluation of the effectiveness of an online calculator in rotated toric lenses to determine best axis

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First Author: K.Varna-Tigka GERMANY

Co Author(s):    T. Kohnen   N. Brui                 

Abstract Details


To evaluate the online calculator after toric premium IOL-implantation and off-axis positioning of the lens.


Ophthalmological University Clinic, Goethe University, Frankfurt am Main, Germany.


Retrospective collection of data from patients after toric-premium -IOL-implantation between 01.01.2018 and 31.12.2019. Collected data included UDVA, BCDVA, UNVA, BCNVA pre-and postoperative, preoperative TCRP, IOL-Models used, power of IOLs, target axis of toric IOL preoperative, and post-surgery axial position. Patients were examined within four weeks after undergoing femtosecond-laser-assisted-cataract surgery.11 patients after toric-IOL-Implantation showed an off-axis result and a significant residual astigmatism after refraction (>0,5 dpt). In those cases, the online calculator was applied to evaluate if a rotation in a new axis would be beneficial for patients’ vision. The toric-IOLs were re-rotated to the ideal axis suggested,and results were evaluated.


No complications occurred during the surgical re-rotation of the lenses and patients were reexamined  one day, one weak one month and six months after surgery. UDVA after the re-rotation of toric IOL was  23% better, but not statistically significant (p=0,105). Preoperative calculated axis and the axis calculated with the online calculator varied about 7%, but not statistically significant (p=0,701). Preoperative calculated residual astigmatism and after online calculator vary about 73% but cause of small number of cases couldn’t be statistic significant (p=0,276). However, the resulting refractions after re-rotating the IOL showed a statistically significatny decrease in the refraction cylinder (p=0,0001) compared with refraction cylinder after the IOL implantation (74% reduced).


In cases with an off-axis toric IOL after successful implantation and residual astigmatism in refraction, using the online calculator is helpful to indicate the ideal axis if a re-rotation of the IOL is considered.

Financial Disclosure:

... research is funded, fully or partially, by a competing company

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