Continuous intraocular pressure recordings during lamellar microkeratotomy of enucleated human eyes

PURPOSE: To analyze the course of intraocular pressure (IOP) during lamellar microkeratotomy (LMK) in enucleated human eyes using 3 microkeratome systems. SETTING: Department of Ophthalmology, Texas Tech University Health Sciences Center, Lubbock, Texas, U.S.A. METHODS: Sixteen enucleated human globes were cannulated through the optic nerve, and IOP was recorded continuously while the eyes had standard LMK flap creation. Three microkeratomes were used: Carriazo-Barraquer (Moria Inc.), Innovatome (Innovative Optics Inc.), and Hansatome (Bausch & Lomb). RESULTS: During the vacuum affixation phase, the IOP reached a mean plateau of 97.9 mm Hg with the Hansatome, 135.8 mm Hg with the Innovatome, and 150.0 mm Hg with the Carriazo-Barraquer. During applanation and cutting, the IOP rose to mean plateau of 154.7 mm Hg, 151.8 mm Hg, and 175.8 mm Hg, respectively. Statistical analysis using Kruskal-Wallis testing suggested a difference in mean IOP elevation between the 3 microkeratomes during the vacuum affixation phase (P = .0394) but no difference during the applanation and cutting phase (P = .506). CONCLUSION: The IOP during LMK was higher than previously reported, and this may increase the risk for complications in certain patient groups.