Intraocular pressure during lamellar cuts with two different microkeratomes

The rapid integration of new technology into ophthalmologic practice, e. g. LASIK (laser in situ keratomileusis), is associated with new complications. The limitations of the new technology cannot be precisely determined. During lamellar cuts with microkeratomes intraocular pressure (IOP) elevations occur. The IOP elevation during the lamellar cut cannot be determined by conventional tonometry.

We examined the IOP rise during the complete microkeratome treatment. Fresh enucleated porcine eyes were cannulated and direct IOP measurement with a Statham manometer was carried out. Thus we evaluated the IOP during the complete treatment for two differently constructed microkeratome systems.

IOP elevations (mean values) between 77 mm Hg for the Corneal Shaper and 229 mm Hg for the Keratek during the vacuum phase and 140 mm Hg for the Corneal Shaper and 360 mm Hg for the Keratek during the lamellar cut were monitored. A sudden IOP decrease to -5 mm Hg was registered for the post-vacuum phase.

In our opinion unphysiologic high IOP values could be dangerous for risk eyes.