| 摘要 |
A plastic lens unit for implant-lens' complete with two, diametrally opposed radial, retention arms, in approximately the same plane as the lens. If each arm is considered as a spoke of a wheel, a short arc of the hypothetical wheel rim is formed at the end of each arm. When implanted, the arms are intended to align approx. with the vertical axis of the eye. The lower arm rim has a comparatively long arc length, e.g. about 60 degrees or a length of some 8 to 12 mm at an outer radius of about 12.5 mm. The upper arm rim has a shorter arc length, pref. about half that of the lower arm rim. The upper arm rim has a narrow, radial slot extending inwards for a short distance from the circumferential edge. This slot is used to grip a short strip of the cell tissue, e.g. iris, of the patient receiving the implantation. The lens, arms and rims can be made all of the same material, esp. PMMA. Alternatively the lens and rims can be made in PMMA while the arms are made of a lens rigid material, such as a hydrogel. Used as a lens for intra-ocular implantation, e.g. following extraction of extra-capsular cataract. |
