Measurement of crystalline lens tilt in high myopic eyes before cataract surgery using swept-source optical coherence tomography

Background:To measure the crystalline lens tilt in eyes with various degrees of myopia before cataract surgery using swept-source optical coherence tomography(SS-OCT).Methods:We used SS-OCT(IOLMaster 700)to scan 131 emmetropic eyes(axial length<24.5 mm),25 mild/moderate myopic eyes(axial length 24.5–26 mm),and 123 high myopic eyes(52,29,and 42 eyes with axial lengths of 26–28,28–30,and>30 mm,respectively)as part of the routine preoperative examination before cataract surgery.SS-OCT involved B-scans along six meridians.The data were analyzed to assess the magnitude and orientation of the lens tilt and their correlation with other optical biometric parameters.Result:The mean tilt was 3.36±0.98°in emmetropic eyes,3.07±1.04°in mild/medium myopic eyes,and 2.35±1.01°in high myopic eyes.Tilt correlated significantly and inversely with axial length(Pearson’s r=−0.427,P<0.001).The crystalline lens tilt predominantly faced the upper outer quadrant relative to the visual axis,symmetrically in both eyes,with mean angles of 24.32°and 147.36°in the right and left eyes,respectively.The variability in the lens tilt direction increased with increasing axial length(χ^(2) test,P<0.001).Conclusion:The magnitude of crystalline lens tilt decreased with increasing axial length.The direction of tilt was predominantly towards the upper outer quadrant in both eyes.The variability in the tilt orientation increased with increasing axial length.Trial registration:NIH(clinicaltrial.gov),NCT03062085.Registered 23 February 2017.