[Foldable implants in cataract surgery at the Geneva Ophthalmological Clinic]

Since 1993, foldable intraocular lenses (Adatomed 90 D, Allergan SI26NB et SI30NB, Chiron C10, Medilas 127) have been implanted through a corneal or scleral tunel after phakoemulsification of the cataract. This retrospective study is made for evaluating the advantages and the disadvantages of these new silicon implants.

The first 250 implantations of a silicon foldable lens compared to 50 rigid PMMA lenses. Problems during implantation, final visual acuity, opacification of the anterior and posterior capsule, decentration of the lens and the stability of the refraction during the 3-19 months following cataract extraction were evaluated.

4 breaks of the capsule, 2 desinsertions of the capsular bag during the implantation of a foldable lens, a difference of less than 0.5 diopter in favour of the foldable lenses, no difference in the incidence of the secondary cataract (p = 0.3) and a more marqued postoperative opacification of the anterior capsule (p = 0.0275) among the foldable silicon lenses were observed.

These results are very encouraging for the visual outcome, but the time of postoperative observations is too short to determine on a long term basis, which is the most important factor for a new implant. To avoid an early opacification of the anterior capsule, a large capsulorhexis, as wide as the optic of the silicon lens, is recommended.