Evaluation Of Physiological Lens Tilt And Decentration Using Longitudinal And High Resolution Swept Source Optical Coherence Tomography: An Epidemiological Study

The study aimed to quantify the physiological lens tilt and decentration of the phakic eye using longitudinal and high resolution swept-source optical coherence tomography.

Department of Ophthalmology and Optometry at the Kepler University Clinic Linz, Austria.

This epidemiological study included patient data collected between June 2020 and October 2022. Requested measurements were two different ss-OCT measurements (IOLMaster700 and Casia2) to investigate on axial eye length, decentration, anterior chamber depth and lens thickness and their influence on lens tilt. Statistical analysis included a descriptive analysis as well as random forest plot machine learning.

In total, 2531 phakic eyes were included in this study. Mean tilt was 4.9° (SD: 1.6; median: 4.9, range: 0.2 to 12.0). A tilt of 7° or more was found in 8.3% (211 cases). In a logistic regression model, standardized coefficients were found to be significant for axial length, decentration, lens equator and chang-waring chord, respectively. Mean decentration was 0.21mm (SD 0.1; median: 0.2, range 0.01 to 1.09) and 0.4mm or more in 5.3% (135 cases).

Pre-operative lens tilt varies significantly between patients and in a small, but relevant number of patients tilt values exceed the critical level of 7 degrees. Phakic lens tilt is associated with several biometric parameters such as axial length, decentration, lens equator and chang-waring chord. Moreover, a decentration of 0.4mm or more can be detected frequently and has a substantial impact on post-operative visual quality. It could be relevant to detect these cases and to include the predicted post-operative tilt and decentration in the IOL power calculation.