Factors influencing long-term regression after posterior chamber phakic intraocular lens implantation for moderate to high myopia.
OBJECTIVE
To evaluate the factors affecting the long-term regression after posterior chamber phakic intraocular lens (Visian ICL; STAAR Surgical) implantation for myopia.


METHODS
Retrospective observational case series.


METHODS
We retrospectively examined 60 eyes of 35 consecutive patients (age, 38.4 ± 9.3 years [mean ± standard deviation]) with myopic refractive errors of -4.00 to -15.25 diopters (D) undergoing ICL implantation. We assessed the amount of myopic regression from 1 month to 6 years after surgery. Stepwise multiple regression analysis was used to assess the factors affecting the amount of myopic regression.


RESULTS
The mean myopic regression from 1 month to 6 years after surgery was -0.33 ± 0.71 D (0.75 to -3.00 D). Explanatory variables relevant to the myopic regression were, in order of influence, patient age (partial regression coefficient B = -0.042, P < .0001) and preoperative axial length (B = -0.186, P = .013) (adjusted R(2) = 0.300). No significant correlation was seen with other clinical factors such as sex, preoperative refraction, intraocular pressure, white-to-white distance, anterior chamber depth, central corneal thickness, or mean keratometric readings.


CONCLUSIONS
Although the great majority of the variance remains unexplained, eyes of older patients and eyes with longer axial length are more predisposed to show greater myopic regression after ICL implantation. These results indicate that not only patient age but also axial length may play some role in predicting the long-term refractive outcomes of this surgical procedure.
Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan. Electronic address: kamiyak-tky@umin.ac.jp.
Kazutaka
K
Kamiya
Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
Kimiya
K
Shimizu
Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
Akihito
A
Igarashi
Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
Hidenaga
H
Kobashi
D000328:Adult; D000367:Age Factors; D058452:Axial Length, Eye / Q000473:pathology; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D047728:Myopia, Degenerative / Q000503:physiopathology / Q000601:surgery*; D054120:Phakic Intraocular Lenses; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult