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The importance of angle kappa evaluation for implantation of diffractive multifocal intra‐ocular lenses using pseudophakic eye model
Author(s) -
Karhanová Marta,
Pluháček František,
Mlčák Petr,
Vláčil Ondřej,
Šín Martin,
Marešová Klára
Publication year - 2015
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/aos.12521
Subject(s) - kappa , ophthalmology , multifocal intraocular lens , lens (geology) , medicine , optics , mathematics , physics , phacoemulsification , geometry , visual acuity
Purpose To determine the critical value of the angle kappa in connection with a higher risk of photic phenomena for the AcrySof Re STOR and Tecnis multifocal intra‐ocular lens ( MIOL ) on a standardized pseudophakic eye model. To analyse the impact of biometric value changes on the critical angle kappa. Methods Geometrical optic rules applied to a suitable optical model of the pseudophakic eye were used to calculate the critical value of the angle kappa for the Tecnis and three types of the AcrySof Re STOR MIOL s. The angle kappa was defined as critical if the incident ray passed through the first ring's edge area. The influence of different positive optical corneal power ( K ), effective lens position ( ELP ) and axial length ( AL ) on the critical angle kappa ( κ c ) was investigated. The dependence of κ c on one of the parameters was studied for standardized values of the remaining parameters. Results The highest value of the critical angle kappa was evaluated for the Tecnis MIOL . The increase in ELP and K caused an increase in κ c under the given conditions. On the contrary, an increase in AL led to lower values of κ c . Conclusion We demonstrated the dependence of the critical angle kappa on the central part of the MIOL and on biometric parameters of the eye, especially on the effective lens position. According to these results, we conclude that shallow anterior chamber depth in connection with a higher angle kappa is an important risk factor for pronounced photic phenomena after implantation of a diffractive MIOL .