Correlation between the pressure-to-cornea index and both structural and functional measures of glaucoma.

ABSTRACT

Purpose: the pressure‑to‑cornea index (PCI) was proposed in order to integrate intraocular pressure and central cornea thickness as a single‑risk factor for glaucoma. The purpose of this study was to correlate the PCI with a structural and two functional measures of glaucoma. Setting: University Hospital in South America. Materials and Methods: Pressure‑to‑cornea index was calculated for 70 eyes of 36 subjects (glaucoma and suspects). Cup‑to‑disc (C/D) ratio, mean deviation (MD) and pattern standard deviation (PSD) as recorded by Humphrey automated perimetry (SITA 24‑2) were correlated with PCI (Pearson’s correlation coefficient). Results: Pearson’s correlation coefficient between PCI and C/D was 0.329 (95% confidence interval [95% CI], 0.09–0.526; P = 0.006); between PCI and MD was − 0.356 MD (95% CI, −0.549 to − 0.126; P = 0.003); and between PCI and PSD was − 0.215 (95% CI, −0.433 to 0.025; P = 0.07). Conclusion: In addition to serve as a single‑risk factor, PCI can be used to stage glaucoma severity as well.