Analysis of clear corneal incision integrity in an ex vivo model.

PURPOSE: To determine the most favorable sutureless incision configuration to minimize extraocular fluid inflow after cataract surgery. SETTING: The Wilmer Eye Institute, Baltimore, Maryland, USA. METHODS: Five fresh human eyes were used in the study. Two 27-gauge needles connected to a saline solution bag and a digital manometer were inserted through the limbus 180 degrees from each other. Intraocular pressure (IOP) was maintained at 15 to 20 mm Hg. Three incisions were performed in different quadrants of each cornea: uniplanar 1.0 mm and 3.0 mm tunnel lengths and 2-step 3.0 mm tunnel length. India ink was applied to the incision site, and IOP fluctuation was induced by applying pressure to the limbal area of the opposite quadrant using an ophthalmodynamometer. Imaging was performed before and after pressure application. RESULTS: The linear distance of India ink inflow after pressure application was higher than the prepressure measurements in the 1.0 mm and 3.0 mm incision groups (P = .039 and P = .023, respectively). The maximum mean of inflow after pressure application was not higher than the prepressure measurement in the 2-step incision group (P = .105). The total ink area measured before and after pressure applications in the incisions of the 3 groups was not significantly different (P = .285). CONCLUSIONS: Intraocular pressure fluctuations may promote entry of bacteria-size particles into the eye when 1.0 mm and 3.0 mm single-plane incisions are performed. Stepped incisions seem to be more resistant to inflow in the presence of IOP fluctuation.