Assessment of Intraocular Pressure Using Three‐Dimensional MR Elastography in Ophthalmologically Normal Individuals
Zheng Gai, Yu Zeng, Juncheng Liang, Chen Zhang, Qijun Wu, Guangrui Chai, Yu Shi ABSTRACT
Background
Elevated intraocular pressure (IOP) is a major risk factor for glaucoma, and accurate assessment is required for diagnosis and management. Goldmann applanation tonometry (GAT) requires corneal contact, whereas non‐contact tonometry (NCT) is susceptible to ocular geometry.
Purpose
To evaluate three‐dimensional MR elastography (3D‐MRE) as a non‐invasive method for IOP assessment.
Study Type
Prospective.
Subjects
Twenty‐nine healthy volunteers (13 females and 16 males, median age: 33).
Field Strength/Sequence
Phase‐contrast spin‐echo echo planar MRE at 3.0 T.
Assessment
IOP measured by GAT (IOPGAT) and NCT (IOPNCT) was obtained. Ocular geometry parameters (central corneal thickness [CCT], mean keratometry [Km], axial length [AL], anterior chamber depth [ACD], and lens thickness [LT]) were measured by optical biometry. The first 10 subjects underwent repeated MRE at 60, 90, and 120 Hz to assess test–retest repeatability, and 90 Hz was used in subsequent acquisitions. Three readers (S.Y., G.Z., and Z.Y., with 12, 3, and 3 years of experiences in MRE, respectively) independently assessed shear stiffness (SS) of the anterior segment and whole eye to evaluate test–retest repeatability and inter‐/intra‐observer agreement.
Statistical Tests
Wilcoxon signed rank test; multivariable regression; intraclass correlation coefficient (ICC); Spearman's correlation; Significance level: p < 0.05.
Results
SS@90 Hz of the anterior segment (SS‐AS@90 Hz) demonstrated excellent repeatability and inter‐/intra‐observer agreement (all ICC ≥ 0.889). IOPGAT demonstrated a stronger correlation with SS‐AS@90 Hz (r = 0.64) than with IOPNCT (r = 0.59). Multivariable regression identified SS‐AS@90 Hz (β = 0.53) and IOPNCT (β = 0.40) as independent predictors of IOPGAT, collectively explaining 58.3% of the variance. No correlation between SS‐AS@90 Hz and CCT (p = 0.10), Km (p = 0.67), ACD (p = 0.90), or LT (p = 0.82) was found, while a significant correlation with AL (r = 0.02) was observed.
Data Conclusion
SS‐AS@90 Hz was identified as a robust biomarker for predicting IOP, independent of most ocular geometric parameters.
Evidence Level
1.
Technical Efficacy
1.