Related Experiment Video
Updated: Jul 16, 2026

Biobanking of Human Aqueous and Vitreous Liquid Biopsies for Molecular Analyses
Published on: September 11, 2023
Infrared spectroscopic examination of aqueous humor
David Weissbrodt1, Ralf Mueller, Jessica Perrin
1Mannheim University of Applied Sciences, Institute for Instrumental Analysis, Mannheim, Germany.
Objective:
The aim of this study was to report on a new technique for examining aqueous humor.
Participants:
Aqueous humor samples obtained from 198 patients (cataract: n=66 eyes; age-related macular degeneration [AMD]: n=66; diabetic macular edema: n=66) were in vitro examined by mid infrared spectroscopy. After training and validating the technique, 66 samples were taken for the final independent prediction.
Results:
In computerized analysis of the spectrometric data, 22 (100%) cataract eyes were diagnosed as the cataract group, 17 (77%) diabetic macular edema eyes were diagnosed as the diabetic macular edema group, and 14 (64%) eyes with AMD were diagnosed as the AMD group. Mid infrared spectrometry could statistically significantly (P=0.004) differentiate between the 3 study groups.
Conclusions:
Mid infrared spectroscopic examination of aqueous humor may be able to differentiate eyes with cataract, AMD, or diabetic macular edema.
Related Concept Videos
Infrared (IR) Spectroscopy: Overview
Different compounds display unique properties due to their...
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to the...
Applications of IR Spectroscopy: Overview
IR and UV–Vis Spectroscopy of Carboxylic Acids
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency, 1710 cm−1. The C=O bond of the...
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
