A new posterior-chamber accommodative IOL (Kellan Tetraflex KH-3500), under investigation in Europe, has shown promise for patients undergoing refractive lens exchange (RLE) with encouraging 6-month refractive results for both distance and near vision.
The KH-3500 IOL, designed by Robert Kellan, MD, is a one-piece hydrophilic acrylic lens with a large 5.75-mm optic, which incorporates the popular square edge design. The optic and haptics are made of polyHEMA and together measure 11.5 mm in length. The lens is available in powers from 5 to 36 D and in half-diopter steps from 10.5 to 29.5 D.
One of the advantages of this posterior-chamber accommodative IOL is its ease of implantation. A standard phaco technique is used, and the lens is injected through a 1.8-mm cartridge. Unlike the CrystaLens, no atropinization is required, allowing for more rapid recovery and avoiding the small but significant risk of morbidity associated with atropine, such as allergic reactions and posterior synechiae from a fixed dilated pupil.
Refractive results were very stable up to 6 months following implantation with this lens. Uncorrected distance vision of 6/12 or better was achieved in 88% of patients, and uncorrected distance vision of 6/7.5 or better was seen in 76% of cases. 70% of cases reported reading J3 (approx N8 equivalent) or better.