New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index Estimation
Purpose. To identify the sources of error in predictability beyond the effective lens position and to develop two new thick lens equations. Methods. Retrospective observational case series with 43 eyes. Information related to the actual lens position, corneal radii measured with specular reflection...
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| Format: | Article |
| Language: | English |
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Wiley
2019-01-01
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| Series: | Journal of Ophthalmology |
| Online Access: | http://dx.doi.org/10.1155/2019/2796126 |
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| author | Joaquín Fernández Manuel Rodríguez-Vallejo Javier Martínez Ana Tauste David P. Piñero |
| author_facet | Joaquín Fernández Manuel Rodríguez-Vallejo Javier Martínez Ana Tauste David P. Piñero |
| author_sort | Joaquín Fernández |
| collection | DOAJ |
| description | Purpose. To identify the sources of error in predictability beyond the effective lens position and to develop two new thick lens equations. Methods. Retrospective observational case series with 43 eyes. Information related to the actual lens position, corneal radii measured with specular reflection and Scheimpflug-based technologies, and the characteristics of the implanted lenses (radii and thickness) were used for obtaining the fictitious indexes that better predicted the postoperative spherical equivalent (SE) when the real effective lens position (ELP) was known. These fictitious indexes were used to develop two thick lens equations that were compared with the predictability of SRK/T and Barrett Universal II. Results. The SE relative to the intended target was correlated to the difference between real ELP and the value estimated by SRK/T (ΔELP) (r = −0.47, p=0.002), but this only predicted 22% of variability in a linear regression model. The fictitious index for the specular reflection (nk) and Scheimpflug-based devices (nc) were significantly correlated with axial length. Including both indexes fitted to axial length in the prediction model with the ΔELP increased the r-square of the model up to 83% and 39%, respectively. Equations derived from these fictitious indexes reduced the mean SE in comparison to SRK/T and Barrett Universal II. Conclusions. The predictability with the trifocal IOL evaluated is not explained by an error in the ELP. An adjustment fitting the fictitious index with the axial length improves the predictability without false estimations of the ELP. |
| format | Article |
| id | doaj-art-eb910a49c2494bbaaa1d47bf6f0f61ec |
| institution | Kabale University |
| issn | 2090-004X 2090-0058 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Ophthalmology |
| spelling | doaj-art-eb910a49c2494bbaaa1d47bf6f0f61ec2025-02-03T01:30:37ZengWileyJournal of Ophthalmology2090-004X2090-00582019-01-01201910.1155/2019/27961262796126New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index EstimationJoaquín Fernández0Manuel Rodríguez-Vallejo1Javier Martínez2Ana Tauste3David P. Piñero4Department of Ophthalmology (Qvision), Vithas Virgen Del Mar Hospital, 04120 Almería, SpainDepartment of Ophthalmology (Qvision), Vithas Virgen Del Mar Hospital, 04120 Almería, SpainDepartment of Ophthalmology (Qvision), Vithas Virgen Del Mar Hospital, 04120 Almería, SpainDepartment of Ophthalmology (Qvision), Vithas Virgen Del Mar Hospital, 04120 Almería, SpainDepartment of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, SpainPurpose. To identify the sources of error in predictability beyond the effective lens position and to develop two new thick lens equations. Methods. Retrospective observational case series with 43 eyes. Information related to the actual lens position, corneal radii measured with specular reflection and Scheimpflug-based technologies, and the characteristics of the implanted lenses (radii and thickness) were used for obtaining the fictitious indexes that better predicted the postoperative spherical equivalent (SE) when the real effective lens position (ELP) was known. These fictitious indexes were used to develop two thick lens equations that were compared with the predictability of SRK/T and Barrett Universal II. Results. The SE relative to the intended target was correlated to the difference between real ELP and the value estimated by SRK/T (ΔELP) (r = −0.47, p=0.002), but this only predicted 22% of variability in a linear regression model. The fictitious index for the specular reflection (nk) and Scheimpflug-based devices (nc) were significantly correlated with axial length. Including both indexes fitted to axial length in the prediction model with the ΔELP increased the r-square of the model up to 83% and 39%, respectively. Equations derived from these fictitious indexes reduced the mean SE in comparison to SRK/T and Barrett Universal II. Conclusions. The predictability with the trifocal IOL evaluated is not explained by an error in the ELP. An adjustment fitting the fictitious index with the axial length improves the predictability without false estimations of the ELP.http://dx.doi.org/10.1155/2019/2796126 |
| spellingShingle | Joaquín Fernández Manuel Rodríguez-Vallejo Javier Martínez Ana Tauste David P. Piñero New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index Estimation Journal of Ophthalmology |
| title | New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index Estimation |
| title_full | New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index Estimation |
| title_fullStr | New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index Estimation |
| title_full_unstemmed | New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index Estimation |
| title_short | New Approach for the Calculation of the Intraocular Lens Power Based on the Fictitious Corneal Refractive Index Estimation |
| title_sort | new approach for the calculation of the intraocular lens power based on the fictitious corneal refractive index estimation |
| url | http://dx.doi.org/10.1155/2019/2796126 |
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