Analysis of the feasibility of measurements and characteristics of intraocular lens tilt using swept-source optical coherence tomography biometer

Objective

To evaluate the feasibility of measurement and characteristics of intraocular lens (IOL) tilt using the swept-source optical coherence tomography (SS-OCT) biometer (IOLMaster 700) and to explore its potentially relevant parameters.

Methods

A cross-sectional study was conducted.Two hundred and forty-two eyes (119 right eyes, 123 left eyes) of 185 patients after phacoemulsification and IOL implantation were included in Beijing Tongren Hospital from July to September 2018.The IOL position, angle κ, angle α, corneal curvature, anterior chamber depth (ACD), pupil diameter (PD), and axial length (AL) were obtained by IOLMaster 700, and the IOL tilt direction and magnitude were calculated.The within-subject standard deviation and intraclass correlation coefficient were used to evaluate the repeatability of three IOL tilt measurements.Binocular symmetry of IOL tilt and the correlation between IOL tilt and different influencing factors were evaluated by Pearson linear correlation analysis or Spearman rank correlation analysis.Influencing factors for IOL tilt were assessed by multiple linear regression analysis.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (No.TRECKY2018-049). Patients were informed of the purpose and methods of this study and signed the written informed consent.

Results

The repeatability of IOL tilt measurements was excellent with a within-subject standard deviation of 5.16° for IOL tilt direction and 0.13° for IOL tilt magnitude.IOL tilt was mirror symmetric in both eyes.The IOL tilt direction in right eyes ranged from -89.60° to 87.53° with a mean of (18.85±29.65)°, and the tilt magnitude ranged from 1.32° to 7.05° with a mean of (4.16±1.26)°.The IOL tilt direction in left eyes ranged from -84.30° to 89.44° with a mean of (21.17±32.38)°, and the tilt magnitude ranged from 0.58° to 7.40° with a mean of (3.80±1.31)°.There were moderate and weak positive correlations of IOL tilt direction and tilt magnitude between both eyes (r=0.473, P<0.001; r=0.335, P=0.011). IOL tilt magnitude was weakly positively correlated with angle α and IOL diopter (r_s=0.272, P=0.003; r=0.285, P=0.002), and was weakly negatively correlated with ACD, PD and AL (r=-0.303, P=0.001; r=-0.233, P=0.011; r_s=-0.331, P<0.001). In backward stepwise regression analysis, the regression equation of IOL tilt magnitude, angle α, ACD, PD, AL and IOL diopter in multiple linear regression analysis was as follows: IOL tilt magnitude=10.503+ 1.456×angle α-0.532×ACD-0.196×AL (R²=0.400; F=8.588, P<0.001).

Conclusions

The SS-OCT biometer can be an effective method to assess IOL tilt.IOL tilt is mirror symmetric between the right eyes and left eyes.

Cataract; Lenses, intraocular; Biometry/instrumentation; Tilt; Direction; Magnitude; Swept-source optical coherence tomography/instrumentation