# Comparison of Intraocular Lens Stability and Reversibility in Phacovitrectomy With Air or Gas Tamponade Using One- and Three-Piece Intraocular Lenses

## TL;DR

This study compares the stability and reversibility of one- and three-piece intraocular lenses after phacovitrectomy with air or gas tamponade.

## Contribution

The study provides new insights into the performance of different intraocular lenses in phacovitrectomy procedures.

## Key findings

- NSP-3 and NX70s showed similar stability in ACD and IOL position with 100% gas or air.
- NSP-3 demonstrated better reversibility than NX70s when gas or air was absent.
- NSP-2 required higher displacement force than NX70s in verification experiments.

## Abstract

Purpose

To compare intraocular lens (IOL) stability and reversibility in phacovitrectomy with air or gas tamponade between one- and three-piece intraocular lenses (IOLs).

Study design

This retrospective cross-sectional study was conducted at Saitama Medical University Hospital from January to July 2023.

Methods

This study involved 19 patients who underwent phacovitrectomy with either air or sulfur hexafluoride gas tamponade and postoperative anterior segment optical coherence tomography. Patients who underwent NSP-3 (NIDEK Co., Ltd., Japan) or NX70s (Santen Pharmaceutical Co., Japan) implantation were evaluated. The displacement force (mN) of the IOL was evaluated in a verification experiment using the NSP-2 (NIDEK Co., Ltd., Japan) and the NX70s. The NSP-2 and NSP-3 share the same lens platform.

Results

The median age was 66 (58, 77) [median (quartiles)] years for NX70s (n=8) and 67 (55, 71) years for NSP-3 (n=11). The anterior chamber depth (ACD) and IOL position values were substantially elevated after the air or gas disappeared for both IOLs. Comparing the IOLs for the ACD and IOL positions at each time point, no significant difference was found in the ACD and IOL position values in 100% gas or air.

However, ACD and IOL position values of the NSP-3 were markedly higher than those of the NX70s in 0% gas or air. In the verification experiment, NSP-2 required a higher IOL displacement force than the NX70s. Following 48 h of 0.5 mm push, the percentage change in the axial distance was smaller for NSP-2 (−6.9%) than for NX70s (−15.5%).

Conclusion

NSP3 was as stable as NX70s in phacovitrectomy with tamponade and demonstrated better reversibility than NX70s.