Consistency study on intraocular pressure measured through different position with different angle by iCare rebound tonometer

Abstract

Objective To analyze the effect of iCare rebound tonometer in different position,different angle measuring on intraocular pressure.Methods Intraocular pressure was measured using the iCare rebound tonometer on the right eyes of 108 subjects in various conditions as follows:first,in an upright position toward the center of the cornea with the probe perpendicular to the corneal plane ; then,at 2 mm from the limbus in the nasal and temporal regions with the probe perpendicular to the corneal plane or along the visual axis; and lastly,with the angled probe touching the central cornea at angles of 10-20°.Paired t-test was used to assess the agreement between the three methods.Pearson's correlation coefficient was used for correlation analysis.Results When the probe was vertical,angle measure central corneal limbal 2 mm nasal and temporal region (0-180 ° along Meridian),IOP respectively was (16.388 9 ± 5.305 32),(16.370 4 ± 5.479 94),(16.435 2 ±5.719 74)mm Hg,and good correlation was found between intraocular pressure and central cornea intraocular pressure and horizontal meridian nasal (r2 =0.910,P ＜ 0.05),temporal (r2 =0.878,P ＜ 0.05).Probe tilt of 10-20°,central cornea intraocular pressure IOP results was (16.472 2 ± 5.339 78)mm Hg,and relevance was found between IOP results and central cornea intraocular pressure with vertical probe (r2 =0.853,P ＜ 0.05).Conclusions iCare tonometer is reliable measurement of intraocular pressure not only through the central region of the cornea but also through corneal peripheral region,no matter whether the probe is vertical or inclined. Key words: Measuring of intraocular pressure; Intraocular pressure; iCare rebound tonometer