# The Intraocular Lens Tilt and Decentration of Two Different Hydrophobic Aspheric Monofocal Intraocular Lenses

## TL;DR

This study compares the positioning of two types of intraocular lenses after cataract surgery, finding that both remain stable and perform similarly over time.

## Contribution

The study provides new empirical data on the long-term stability and optical performance of two hydrophobic aspheric monofocal IOLs.

## Key findings

- Both IOLs showed no significant differences in tilt and decentration over 180 days.
- Visual acuity improved significantly for both IOL groups at all follow-up visits.
- IOL tilt and decentration remained within clinically acceptable limits and did not affect visual outcomes.

## Abstract

To evaluate the clinical performance of two monofocal aspheric intraocular lenses (IOLs) to determine their position in the capsular bag after implantation.

This retrospective study collates data from the medical records of patients who underwent cataract surgery and were implanted with two different hydrophobic aspheric monofocal IOLs. A total of 6 visit data were considered in the study, out of which four follow-up visits were on day 1, 7, 30, and 180 postoperatively. The investigational variables included IOL tilt and decentration, uncorrected and best corrected visual acuity (UCVA and BCVA), contrast sensitivity, manifest refraction, intraocular pressure, and posterior capsule opacification.

A total of 85 subjects’ medical records were screened. Nineteen subjects discontinued the study due to loss to follow-up. Thirty subjects’ medical records were enrolled in the IOL 1 arm, and 36 subjects’ medical records were enrolled in the IOL 2 arm. There were no statistically significant differences in vertical and horizontal IOL tilt and decentration results between IOL 1 arm and IOL 2 arm. Within-group analysis revealed a significant difference in BCVA at all visits from baseline for both the IOL 1 and IOL 2 arms. In the between-group analysis, there were no significant differences in BCVA at any visit between the IOL 1 and IOL 2 arms.

Tilt and decentration of IOL may occur secondary to complicated cataract surgery or following uneventful phacoemulsification. IOL tilt up to 2-3 degrees and decentration of 0.2-0.3 mm are common and not clinically significant. Larger amounts of decentration and tilt deteriorate the optical performance of the IOLs, subsequently affecting the patients’ vision.

IOL vertical and horizontal tilt and decentration found in the current study are within the limits reported in the literature. The position of these two lenses in the capsular bag remains very stable at day 180 after implantation.