Pars plana lensectomy by ultrasonic fragmentation. II. A poor procedure for routine cataract extraction.

Removal of the lens through a pars plana incision may be carried out with an aspiration-cutting device in young soft lenses, and with ultrasonic fragmentation, combined with an aspiration-cutting probe, in older, harder lenses. Extremely hard lenses cannot be efficiently removed through small incisions. These techniques are most useful when combined with a pars plana vitrectomy so that the same sized incision may be used for both procedures. In a few other selected situations, lensectomy through a pars plana incision is also advantageous. Adoption of this incision site for routine senile cataracts in unwarranted because: 1) small gauge instruments have little ability to remove very hard lenses; 2) vitreous must be incised in all cases, opening the door to unnecessary complications; and 3) loss of lens fragments into the posterior segment in 30-40% of eyes produces an unacceptably complex surgical procedure compared to limbal extraction.