JAN 24, 2013
This study found that slow IOL insertion may affect clear corneal wound structure more than fast IOL insertion, and this appeared to be due to vertical stretching of the insertion cartridge by the IOL. To the authors' knowledge, this is the first study to directly consider the possibility that the time required for an IOL to pass through the wound during insertion may affect wound damage.
They randomized 80 eyes undergoing clear corneal phacoemulsification to either fast IOL insertion (one revolution per second) or slow IOL insertion (one-quarter revolution per second). A screw plunger-type injector was used in both groups.
The change in wound size after IOL insertion was significantly larger in the slow group (P = 0.002). More eyes in the slow group required corneal hydration (P = 0.04), and wound structure changes on OCT were more prominent (P = 0.003). There were no significant differences in surgically-induced astigmatism.
Laboratory examination of the insertion cartridges showed that the vertical diameter of the cross-sectional area was significantly larger when the IOL was loaded than when the cartridge was empty. They write that vertical stretching of the cartridge may lead to extensive stress being exerted on the wound because a cataract surgical incision is usually made transversely.
They conclude that these findings suggest that a surgeon should insert the IOL quickly to lessen wound damage. However, caution must be used with the quick-insertion method because rapid insertion might induce tissue injury, especially with a wound-assisted method.