- Journal of Refractive Surgery
- November 2010 - Volume 26 · Issue 11: 858-862
To investigate the mechanism of action of the Tetraflex (Lenstec Kellen KH-3500) accommodative intraocular lens (IOL).
Thirteen eyes of eight patients implanted with the Tetraflex accommodating IOL for at least 2 years underwent assessment of their objective amplitude-of-accommodation by autorefraction, anterior chamber depth and pupil size with optical coherence tomography, and IOL flexure with aberrometry, each viewing a target at 0.0 to 4.00 diopters of accommodative demand.
Pupil size decreased by 0.62±0.41 mm on increasing accommodative demand, but the Tetraflex IOL was relatively fixed in position within the eye. The ocular aberrations of the eye changed with increased accommodative demand, but not in a consistent manner among individuals. Those aberrations that appeared to be most affected were defocus, vertical primary and secondary astigmatism, vertical coma, horizontal and vertical primary and secondary trefoil, and spherical aberration.
Some of the reported near vision benefits of the Tetraflex accommodating IOL appear to be due to changes in the optical aberrations because of the flexure of the IOL on accommodative effort rather than forward movement within the capsular bag.
From Aston University, School of Life and Health Sciences, Ophthalmic Research Group, Birmingham, United Kingdom (Wolffsohn, Davies, Gupta, Naroo, Gibson, Shah); Midland Eye Institute, Birmingham, United Kingdom (Shah); and Topcon, Tokyo, Japan (Mihashi).
No financial support was received for this study. The School of Life and Health Sciences at Aston University, however, receives financial support from a variety of intraocular lens companies including Lenstec (St Petersburg, Florida). Dr Mihashi is an employee of Topcon (Tokyo, Japan). The remaining authors have no commercial interest in the materials presented herein.
This study was presented in part at the Lens, Refractive & Wavefront Summit ARI/WFC 2009; March 5–7, 2009; Alicante, Spain.
Correspondence: James S. Wolffsohn, PhD, Aston University, School of Life and Health Sciences, Ophthalmic Research Group, Aston Triangle, Birmingham, United Kingdom. Tel: 44 121 204 4140; Fax: 44 121 204 4048; E-mail: email@example.com