| 摘要 |
A posterior chamber intraocular lens for implantation into an eye between the posterior capsule (20) and the anterior capsular flap (19) of the residual capsular bag that remains in the eye following an extracapsular cataract extraction, comprising: (a) an optic (11) having anterior and posterior surfaces; and (b) a pair of haptics connected with said optics for positioning said optic properly in said residual capsular bag; (i) said haptics being constituted by two resiliently flexible, concentric, closed, planar rings (12, 13) having different diameters and extending around the entire perimeter of said optic, (ii) the smaller of said rings being connected to the peripheral edge of said optic by a first pair of bridging elements (14A, 15A) extending generally diametrically of said smaller ring, (iii) the larger of said rings being connected to said smaller ring by a second pair of bridging elements (16A, 17A) extending generally diametrically of said larger ring, with each of said first bridging elements being proximate to a respective one of said second bridging elements, (iv) the plane of said larger ring being parallel to but offset anteriorly from the plane of said smaller ring, and (v) the outer diameter of said larger ring at its outer periphery being slightly larger than the inner diameter of said residual capsular bag in the equatorial region thereof; (c) whereby, upon proper implanatation of the lens into the eye, (i) said larger ring presses along its entire circumference against the interior surface of said residual capsular bag in the equatorial region thereof without overstressing the latter and without engendering an unfurling of said anterior capsular flap, said larger ring thereby constituting a primary mechanical barrier for inhibiting migration of epithelial cells from said equatorial region onto and toward the optic region of said posterior capsule of said residual capsular bag, (ii) said smaller ring presses along its entire circumference against the anterior surface of said posterior capsule a short distance radially inwardly of said equatorial region to constitute a secondary mechanical barrier for inhibiting migration, over said posterior capsule and toward said optic region thereof, of epithelial cells that were not blocked by said larger ring, and (iii) the optic region of said posterior capsule is maintained flush and taut against said posterior surface of said optic inhibiting formation of Elschnig's pearls in the optic region of said posterior capsule. |
