Posterior Chamber Phakic Intraocular Lenses for the Correction of Myopia: Factors Influencing the Postoperative Refraction

Pedro Serra,Santiago Cerpa Manito,Ángel Sánchez Trancón,Oscar Torrado Sierra,António Baptista

doi:10.3390/opt2040028

Pedro Serra, Santiago Cerpa Manito + Show 3 more

Open Access

https://doi.org/10.3390/opt2040028

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Abstract

Posterior chamber phakic intraocular lens implantation is a refractive technique for the correction of myopia. This study aimed to identify those factors contributing to variability in postoperative refraction. Methods: This retrospective study evaluated 73 eyes (one eye per patient) implanted with myopic implantable collamer lenses (ICL). Eyes were divided into two groups, the low myopic group (LMG) (ICL > −9.5 DS) and the high myopic group (HMG) (ICL ≤ −9.5 DS), to compare the predictability, efficacy index, and postoperative refraction between groups. The association of postoperative refraction with anatomical, demographic, and optical features was assessed through correlation analysis and investigated using ray-tracing. Results: Postoperative refraction at 3 months for the whole group was close to emmetropia at −0.02 ± 0.37 DS, the LMG tended toward myopia and the HMG, toward hyperopia. The results showed that 65% and 54% of the eyes had postoperative refraction of within ±0.25 DS, respectively, in the LMG and HMG, and in both groups, 100% were within ±1.00 DS. ICL implantation had a higher efficacy index in the HMG (1.13 ± 0.15) than in the LMG (1.04 ± 0.15). Postoperative refraction was positively associated with the vault (R = 0.408) and negatively correlated with ICL power (R = −0.382). Conclusion: The predictability and effectiveness of ICL implantation is high in a wide range of myopias. Considering the expected vault and including accurate vertex measurements would contribute to improving the predictability of the results.

Highlights

Phakic posterior chamber intraocular lenses are an established form of refractive surgery that is widely used in the correction of myopia and astigmatism
The present study evaluated the refractive predictability and efficacy index of implantable collamer lenses (ICL)
The results confirmed that ICL is a predictable implantation in the correction of myopia

Summary

Introduction

Phakic posterior chamber intraocular lenses are an established form of refractive surgery that is widely used in the correction of myopia and astigmatism. The implantable collamer lens (ICL, STAAR Surgical, Monrovia, CA, USA) represents one of the many phakic intraocular lenses (IOL) available on the market, the material being based on a polymeric combination of hydroxyethyl methacrylate and porcine collamer [1]. An important advantage of these lenses over other forms of refractive surgery procedures is their applicability in high myopias, with ICL powers ranging from –18.00 to −1.00 diopter sphere (DS). The refractive results of 1905 myopic eyes implanted with. ICLs showed that ~91% of the eyes had a postoperative refractive error within ±0.50 DS, and ~99% were within ±1.00 DS. The results confirm the high refractive predictability

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