Correlation of Tono-Pen and Pneumatonometer Measurements from Four Scleral Quadrants with Intraocular Pressure Measurements from the Cornea

Abstract

Objective: To assess whether Tono-Pen and pneumatonometer measurements obtained from the sclera correlate to intraocular pressure measurements obtained from the cornea.Methods: This is a prospective, cross-sectional study, conducted at the New York Eye and Ear Infirmary of Mount Sinai. Patients were randomized to have their left or right eye included in the study. Exclusion criteria included prior intraocular surgery (except uncomplicated cataract extraction), uveitis, corneal or scleral thinning, central corneal thickness <500 µm or >575 µm, and hyperopia greater than +2 diopters or myopia greater than -4 diopters. Goldmann applanation tonometry, Tono-Pen and pneumatonometer measurements were obtained from the cornea. Tono-Pen and pneumatonometer measurements were obtained from the sclera in the superonasal, superotemporal, inferonasal, and inferotemporal quadrants. Product moment correlation and linear regression were used to examine correlations between the measurements. Conclusion: S-IOP measurements, especially from the superotemporal and inferotemporal quadrants, can provide useful information about intraocular pressure in eyes in which accurate C-IOP measurements cannot be obtained.

International comparisons of intraocular pressures, as measured by Tono-Pen and Goldmann applanation tonometry, in healthy adults: A meta-analysis

“…This variability and inconsistencies in reported studies have resulted in a confused professional literature. The variability has been explained by differences in research study designs, [3] research methods applied, [4] statistical approaches used to analyze IOP measurements, [5,6] eye biomechanics, [7,8] diurnal variations of IOP, [9] body positions in which measurements were taken (sitting or supine), [10,11] age of subjects, [12–14] ethnicity of subjects, [15] central corneal thickness (CCT), [7,16–21,29] cornea shape, [22] level of training and skill of eye care professional making the measurements (ophthalmologist, technician), [23,24] subjectivity of GAT measurements, [25,26] and fundamental principles of physics underlying the differences in how IOP are measured by the TP or GAT procedure. [7,22,27,28,30]…”