Comparison of intraocular stability of intraocular lenses with different haptic designs after cataract surgery and its influencing factors

Objective  To observe and analyze the intraocular stability of intraocular lens (IOL) with different haptic designs after cataract surgery by swept-source optical coherence tomography (SS-OCT) and analyze its influencing factors.

Methods  A cohort study was conducted.Medical records of 130 consecutive patients (130 eyes) diagnosed with age-related cataract, who underwent phacoemulsification and IOL implantation at The First Affiliated Hospital of Zhengzhou University from August 2021 to August 2022 were collected.According to the type of IOL implanted, the patients were divided into four groups, L-haptic group with 34 cases (34 eyes), modified C-haptic group with 30 cases (30 eyes), plate-haptic group with 36 cases (36 eyes), four-haptic group with 30 cases (30 eyes).Before surgery, the patient’s axial length and IOL diopter were measured with an optical biometer, and the angle kappa and angle alpha were measured with corneal topography.At 3 months after surgery, the anterior chamber depth, decentration and tilt of IOL, the space area between IOL and posterior capsule (AREAP) of the four groups were measured using SS-OCT.And anterior chamber depth changes and diopter changes were calculated.This study complied with the Declaration of Helsinki.The study protocol was reviewed and approved by the Medical Ethics Committee of The First Affiliated Hospital of Zhengzhou University (No.2022-KY-1222-002).All subjects were aware of the purpose and significance of this study and voluntarily signed the informed consent form.

Results  The average decentration and tilt of the modified C-haptic, L-haptic, plate-haptic, and four-haptic IOL decreased successively at 3 months after surgery, with no statistically significant differences ( H=7.055, F=5.162; all P>0.05).The postoperative anterior chamber depth, the anterior chamber depth change, the diopter change and the AREAP of the modified C-haptic, L-haptic, plate-haptic, and four-haptic IOL decreased successively at 3 months after surgery, and the differences were statistically significant (all P<0.05).Preoperative angle kappa was positively correlated with postoperative 3-month IOL tilt ( r=0.554, P<0.001).Preoperative angle alpha was positively correlated with postoperative 3-month IOL tilt ( r=0.469, P<0.001).The multiple linear regression model constructed with preoperative angle kappa and preoperative angle alpha as independent variables and IOL tilt as dependent variable was statistically significant ( F=39.526, P<0.001, R ²=0.384).For every 1 mm increase in preoperative angle kappa, postoperative tilt will increase by 0.438°; for every 1 mm increase in preoperative angle alpha, postoperative tilt will increase by 0.300°.

Conclusions  All four IOLs with different haptic designs have good horizontal centering stability.The plate-haptic and the four-haptic IOLs have superior vertical stability compared to L-haptic and modified C-haptic designs.Preoperative angles kappa and alpha can be used as indicators to predict postoperative IOL tilt.

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