Standardized Seidel test to evaluate different sutureless cataract incision configurations

To compare aqueous outflow and India ink inflow to evaluate clear corneal incisions (CCIs).

Wilmer Eye Institute, Baltimore, Maryland, USA.

Two 25-gauge needles connected to a salt solution bag and to a digital manometer were inserted through the limbus of human donor corneas 120 degrees apart from each other. Three 2.75 mm wide incisions were created in a different third of each cornea as follows: single-plane 1.50 mm tunnel length, single-plane 3.00 mm tunnel length, and 2-step 3.00 mm tunnel length. The Seidel test was evaluated at 5 intraocular pressures (IOPs) in the physiologic range. A masked observer evaluated the recorded tests. With a preset 10 mm Hg IOP, India ink was applied to the incision site and a sudden IOP fluctuation induced. India ink influx was outlined and measured by planimetry.

With the 1.5 mm single-plain incisions, all 6 globes showed inflow and outflow. With the 3.0 mm single-plain incisions, all 6 globes showed inflow and 2 showed outflow by the Seidel test. With the 3.0 mm 2-step incisions, 2 globes showed inflow and 3 had positive Seidel test results. Area and length of inflow were statistically significantly greater with the 2 single-planed incisions than with the 2-step incisions.

This human ex vivo model showed that wound deformation produced during Seidel testing might not be an accurate way to predict the risk for bacterial invasion in the early postoperative period.