Related Experiment Video
Updated: Jun 14, 2026
Corneal Sensitivity Testing Procedure for Ophthalmologic and Optometric Patients
Published on: August 2, 2024
The 31P spectral modulus and corneal metabolism
Jack V Greiner1, Tamara I Snogren2, Thomas Glonek3
1Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Schepens Eye Research Institute of Massachusetts Eye & Ear, Boston, MA, USA; Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA; Clinical Eye Research of Boston, Boston, MA, USA; Magnetic Resonance Laboratory, Chicago College of Osteopathic Medicine, Chicago, IL, USA.
Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy measures corneal metabolic health using the phosphorus spectral modulus (PSM). Higher PSM values indicate healthier corneas, even with low signal detection.
Area of Science:
- Ophthalmology
- Biochemistry
- Medical Imaging
Background:
- Corneal metabolic health is crucial for tissue maintenance.
- Assessing metabolic status in individual corneas presents challenges.
- Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy offers a potential solution.
Purpose of the Study:
- To introduce and validate the phosphorus spectral modulus (PSM) as an index of corneal metabolic health.
- To demonstrate the utility of 31P NMR spectroscopy for assessing metabolic status in corneas.
- To establish a method for measuring metabolic health in individual corneas, even under metabolic stress.
Main Methods:
- Utilized phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy to analyze organophosphates in corneal tissues.
- Calculated the phosphorus spectral modulus (PSM) from the 31P NMR spectrum, representing the ratio of high-energy to low-energy phosphates.
- Employed the integral function of 31P NMR spectroscopy for measurements with low signal-to-noise ratios.
Main Results:
- The PSM effectively differentiates between metabolically healthy and stressed corneas.
- Normal corneas exhibited a higher average PSM (1.16±0.06) compared to stressed corneas (0.80±0.12).
- PSM determination is feasible even with minimal tissue volume and low signal-to-noise spectra.
Conclusions:
- The PSM is a reliable numerical assay for assessing corneal metabolic health.
- Higher metabolic activity correlates with a higher PSM.
- This method is suitable for evaluating individual corneas, offering a valuable tool for research and clinical applications.
