Analysis of the capsule edge after Fugo plasma blade capsulotomy, continuous curvilinear capsulorhexis, and can-opener capsulotomy

Purpose

To compare the quality of the edges of anterior capsulotomies performed in porcine eyes using 3 different techniques.

Setting

David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA.

Methods

Four porcine eyes were submitted to the center in 10% neutral buffered formalin. The cornea of the eyes had been removed, and a continuous capsulotomy had been performed in each eye using the Fugo plasma blade. To provide morphologic correlation, 4 additional porcine eyes were used in the study. In 2, a manual continuous curvilinear capsulorhexis (CCC) was performed after the cornea or cornea/iris was removed and in the other 2, a can-opener capsulotomy (COC) was performed. The eyes were then placed in 10% neutral buffered formalin. Gross (macroscopic) and microscopic analysis of each eye was performed, and photographs were taken. One eye in each group was also prepared and analyzed under scanning electron microscopy (SEM).

Results

The capsulotomy margin in the Fugo blade group presented some regularly spaced tags directed centrally with smooth edges at the base. Such a configuration would not interfere with the dynamics of the capsulorhexis sphincter and would generally not lead to radial tears. The smooth and regular nature of the capsulotomy margin in the CCC group was confirmed by gross and microscopic examinations of the eyes. The capsulotomy margin in the COC group presented some sharp notches directed outward, irregularly spaced, and irregular in shape. These are known to have a tendency to extend and form radial tears.

Conclusion

Although performance of an anterior capsulotomy with the Fugo blade was associated with some margin irregularities, the geometry of the centrally directed tags prevented them from becoming the site of radial tear formation. The base of the capsulotomy performed with the Fugo blade appeared to be almost as smooth and regular as in the CCC under SEM evaluation.