Agreement and repeatability of a novel portable transpalpebral tonometer for home tonometry versus non-contact and rebound tonometry

A newly developed handheld device, the IC01 transpalpebral tonometer, was engineered to determine intraocular pressure (IOP) autonomously through upper eyelid palpation. This study aimed to evaluate the repeatability of the IC01 and to investigate its agreement with a non-contact tonometer (TOPCON CT-800). A comparative design was employed to analyze the agreement in IOP measurements between the innovative IC01 device and both the non-contact (TOPCON CT-800) and rebound (iCare IC200) tonometers, as well as its repeatability. Trained operators recorded measurements from 189 subjects at both the initial and one-month follow-up visits, adhering to a randomized sequence. IOP measurements from the IC01 showed no statistically significant difference from those obtained with the iCare IC200 or TOPCON CT-800. Repeatability, indicated by the intraclass correlation coefficient, averaged 0.77 for right eyes and 0.75 for left eyes. Furthermore, the mean IOP values at the one-month follow-up were 8.65 ± 4.15 mmHg for the right eye and 7.68 ± 2.61 mmHg. No sight-threatening adverse events occurred. Regarding patient preference among a subset of 69 respondents, 46.37% (n = 32) favored the IC01, compared to 17.39% (n = 12) for the TOPCON CT-800, while 36.23% (n = 25) expressed no preference. Gender did not show a significant correlation with outcomes. However, participants aged 50 years or younger demonstrated a greater preference for the IC01 (χ² = 5.68, P = 0.012). The IC01 tonometer demonstrated clinical equivalence to established devices, showing superior repeatability and higher patient acceptance. Its distinctive practical advantages include the avoidance of corneal contact, operational independence from a clinician, and a design suitable for self-monitoring in a home environment.