TY - JOUR
T1 - Predictability of different calculators in the minimization of postoperative astigmatism after implantation of a toric intraocular lens
AU - Ribeiro, Filomena J.
AU - Ferreira, Tiago B.
AU - Relha, Catarina
AU - Esteves, Carina
AU - Gaspar, Sylvia
PY - 2019
Y1 - 2019
N2 - Purpose: To assess the efficacy of five calculators for toric intraocular lenses (IOL). Methods: Retrospective comparative case series in cataract patients undergoing implantation of trifocal toric IOLs (PhysIOL FineVision POD FT). Inclusion criteria were age-related cataract and a corneal astigmatism between 0.90D and 4.50D. Refractive astigmatism predictability of five different toric calculators or calculation methods were compared. Furthermore, two groups were differentiated according to the type of astigmatism. The mean absolute error and the centroid errors in the predicted residual astigmatism from each calculator were evaluated. Results: Fifty-one eyes of 43 patients were included in the study. For the standard toric calculator using anterior keratometry values only, the centroid prediction error was 0.39D±0.41@166°, which was reduced by the application of the PhysIOL toric calculator that includes the Abulafia-Koch regression formula and adjustment for the effective lens position (0.05D±0.34@167°), and also by the application of the Barrett toric calculator (0.07D±0.28@160°). Regarding the techniques that directly evaluate posterior corneal surface, the Holladay toric calculator, using total corneal power provided by a color-LED topographer, generated better results (0.10D±0.44@156°) than those using Scheimpflug camera data (0.23D±0.56@158°). Similar results were found for both types of astigmatism. Conclusion: The PhysIOL and the Barrett toric calculators taking into account the posterior corneal astigmatism by mathematical models, yielded lower astigmatic prediction errors compared to a standard toric calculator based on anterior keratometry data only. When total corneal power measurements were used, prediction errors were lower with color-LED than with Scheimpflug based topography.
AB - Purpose: To assess the efficacy of five calculators for toric intraocular lenses (IOL). Methods: Retrospective comparative case series in cataract patients undergoing implantation of trifocal toric IOLs (PhysIOL FineVision POD FT). Inclusion criteria were age-related cataract and a corneal astigmatism between 0.90D and 4.50D. Refractive astigmatism predictability of five different toric calculators or calculation methods were compared. Furthermore, two groups were differentiated according to the type of astigmatism. The mean absolute error and the centroid errors in the predicted residual astigmatism from each calculator were evaluated. Results: Fifty-one eyes of 43 patients were included in the study. For the standard toric calculator using anterior keratometry values only, the centroid prediction error was 0.39D±0.41@166°, which was reduced by the application of the PhysIOL toric calculator that includes the Abulafia-Koch regression formula and adjustment for the effective lens position (0.05D±0.34@167°), and also by the application of the Barrett toric calculator (0.07D±0.28@160°). Regarding the techniques that directly evaluate posterior corneal surface, the Holladay toric calculator, using total corneal power provided by a color-LED topographer, generated better results (0.10D±0.44@156°) than those using Scheimpflug camera data (0.23D±0.56@158°). Similar results were found for both types of astigmatism. Conclusion: The PhysIOL and the Barrett toric calculators taking into account the posterior corneal astigmatism by mathematical models, yielded lower astigmatic prediction errors compared to a standard toric calculator based on anterior keratometry data only. When total corneal power measurements were used, prediction errors were lower with color-LED than with Scheimpflug based topography.
KW - Astigmatism
KW - Toric IOL
KW - Toric IOL calculation
UR - http://www.scopus.com/inward/record.url?scp=85073362821&partnerID=8YFLogxK
U2 - 10.2147/OPTH.S213132
DO - 10.2147/OPTH.S213132
M3 - Article
C2 - 31695316
AN - SCOPUS:85073362821
VL - 13
SP - 1649
EP - 1656
JO - CLINICAL OPHTHALMOLOGY
JF - CLINICAL OPHTHALMOLOGY
SN - 1177-5483
ER -