Relationship between Crystalline Lens Thickness and Shape and the Identification of Anterior Ocular Segment Parameters for Predicting the Intraocular Lens Position after Cataract Surgery.

Tsukasa Satou,Kimiya Shimizu,Manabu Koshimizu,Takahiro Niida,Akihito Igarashi,Shuntaro Tsunehiro,Sayaka Kato

doi:10.1155/2019/3458548

Abstract

Purpose This study was performed to investigate the relationships among crystalline lens shape, actual intraocular lens (IOL) position, and crystalline lens thickness (LT), as measured by anterior segment optical coherence tomography (AS-OCT), and to determine anterior ocular segment parameters that predict postoperative IOL position. Methods Seventy-nine eyes of 79 patients who underwent uneventful cataract surgery were enrolled. For crystalline lens preoperative anterior segment data, the LT, and anterior, equatorial, and posterior surface depths (ASD, ESD, and PSD, respectively) of crystalline lenses were quantitatively determined. For postoperative anterior segment data, the actual IOL position was quantified. Moreover, the following correlations were analyzed: LT with the ASD, ESD, PSD, and IOL position; IOL position with the ASD, ESD, and PSD; and refractive prediction error with the difference between the predicted postoperative anterior chamber depth (ACD) of the SRK/T formula and the IOL position, ASD, ESD, and PSD (each depth minus the predicted postoperative ACD of the SRK/T formula). Results The LT was significantly correlated with the ASD (r = -0.65) and PSD (r = 0.41), whereas it was not correlated with the ESD or IOL position. The IOL position was significantly correlated with the ASD (r = 0.67), ESD (r = 0.72), and PSD (r = 0.74). The refractive prediction error was significantly correlated with the difference between the predicted postoperative ACD of the SRK/T formula and the IOL position (r = 0.65), ASD (r = 0.46), ESD (r = 0.54), and PSD (r = 0.58). Conclusions The ESD and PSD obtained using AS-OCT were highly correlated with the IOL position and significantly correlated with the refractive prediction error. These findings suggest that the ESD and PSD may enhance the accuracy of actual IOL position prediction.

Highlights

Today, it is common knowledge that cataract surgery includes elements of refractive and presbyopic surgery, in addition to removal of the diseased tissue [1,2,3,4,5]
Norrby et al [6] demonstrated that preoperative prediction of the postoperative intraocular lens (IOL) position contributed to the greatest proportion of IOL power prediction errors
The refractive prediction error was significantly correlated with the difference between the anterior IOL surface position and the predicted postoperative anterior chamber depth (ACD) of the SRK/T formula (p < 0.001) (Figure 7)

Summary

Introduction

It is common knowledge that cataract surgery includes elements of refractive and presbyopic surgery, in addition to removal of the diseased tissue [1,2,3,4,5]. Implanting an intraocular lens (IOL) with the appropriate power calculation during cataract surgery affects patient satisfaction and leads to a successful surgery. Norrby et al [6] demonstrated that preoperative prediction of the postoperative IOL position (i.e., postoperative anterior chamber depth [ACD]) contributed to the greatest proportion of IOL power prediction errors. Improving the predictive accuracy of the IOL position is essential for reducing postoperative refractive error. The postoperative ACD that is included in well-known, third-generation IOL power calculation formulas (SRK/T [7], Holladay 1 [8], and Hoffer Q [9]) does not reflect the true postoperative ACD in the anatomical sense, because it is calculated using thin lens formulas.

Methods

Results

Conclusion