Intraocular pressure with miniscleral contact lenses

Abstract

To evaluate the influence of rigid gas permeable miniscleral contact lenses on intraocular pressure (IOP), keratometry readings and corneal thickness, and to study the correlation between scleral (IOPs) and corneal (IOPc) intraocular pressure using the Icare ic100 tonometer (model TAO11, Icare Finland Oy). The study included 99 volunteers without history of ocular diseases. The first group consisted of 66 participants (122 eyes) aged 22.3±2.2 years - IOPc and IOPs were measured by the Icare ic100 tonometer in order to determine the correlation. The second group (33 participants, aged 22.7±1.7 years) - day 1, diurnal IOPc and IOPs fluctuations were measured; on day 2, a miniscleral lens (diameter 14.9 mm) was placed on the study eye and was worn for 6 hours, the paired eye served as control. IOP was measured before, after lens placement, after 2 hours of lens wear, and before and after lens removal. Corneal topography was evaluated before and after lens removal. In the first group, there was a weak but significant correlation between IOPc and IOPs (Spearman correlation coefficient 0.285, p=0.001). In the second group, IOPc in the study eye before lens placement (14.8±3.8 mm Hg) and IOPc after its removal (13.6±3.9 mm Hg) were not different from those in the control eye. There were also no statistically significant changes in IOPs before, during lens wear, and after lens removal. The central corneal thickness increased by 2.9% (p<0.001) after 6 hours of lens wear. In young individuals without history of ocular diseases, wearing the miniscleral lens for 6 hours does not have significant influence on IOP and does not cause clinically significant corneal edema.