# Ophthalmic Time-resolved Confocal Scanning Microfluorometer

> **NIH NIH R43** · ISS, INC. · 2020 · $194,848

## Abstract

Project Summary
This project, titled Ophthalmic Time-resolved Confocal Scanning Microfluorometer (OTR-CSMF), is aimed at
building a dedicated confocal microfluorometer capable of depth-resolved fluorescence spectroscopy across
the cornea for reconstruction of a map of physiological parameters (ph, O2, etc.). At the end of Phase I stage,
the instrument will be able to perform both intensity and fluorescence lifetime measurements across the cornea
at different depths with a high depth resolution (< 7 µm) for several hours. The instrument will be based on two
established technologies: (i) Confocal scanning microfluorometer (CSMF) [developed by Dr. Srinivas at Indiana
University (IU)], and (ii) Digital Frequency Domain technology (DFD) [developed and being marketed by ISS
Inc.]. OTR-CSMF is a unique instrument capable of measuring fluorescence across the depth of the cornea
with a high depth resolution. It has been applied in several contexts to investigate transcorneal kinetics of
fluorophores, corneal physiology, and labeled nanoparticles. The DFD technology, developed for fluorescence
lifetime measurements, is highly matured and is routinely configured in spectrometers being sold by ISS Inc.
The goal of this Phase I project is to establish a fully functional prototype of the CSMF-DFD system and enable
for the first time an innovative device capable of trans-corneal fluorescence lifetime measurements.
The prototype of the CSMF-DFD system will be developed through the following steps: (1) Integrate the CSMF
previously developed at Indiana University with the hardware of the DFD technology of ISS Inc. into a single
compact unit. Recast the data acquisition and analysis software (Vinci) being used in the ISS
spectrofluorometers to enable real-time determination of depth-resolved lifetime with the CSMF-DFD system.
(2) The prototype CSMF-DFD system will then be employed to verify its accuracy based on measurements of
lifetime of fluorescein (lifetime ~ 4 ns) and pO2-sensitive nanoparticles of ruthenium phenanthroline
(Ru(Phen)3; lifetime ~ 300 ns - 5 µs) in a microfluidic chamber. Finally, we will perform a pilot study of depth-
resolved lifetime measurements in rabbit corneas ex vivo to determine the transcorneal pO2 profile and relative
binding of fluorescein across the tissue. These goals are based on successful feasibility studies conducted by
ISS Inc. and Dr. Srinivas of IU over several months.
Once the CSMF-DFD system is fully developed, it will permit unprecedented fluorescence lifetime
measurements across the cornea ex vivo. Subsequent modifications in the next phase of the development will
enable its applications to small animals (in vivo) and extend measurements to the anterior segment of the eye.
Overall, the availability of the CSMF-DFD system will spur novel applications to unravel the pathophysiology of
the cornea (e.g., epithelial dysfunction, keratoconus, and Fuchs dystrophy) and the anterior segment. Thus,
the instrument not only enhan...

## Key facts

- **NIH application ID:** 10080180
- **Project number:** 1R43EY032002-01
- **Recipient organization:** ISS, INC.
- **Principal Investigator:** Beniamino Barbieri
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $194,848
- **Award type:** 1
- **Project period:** 2020-09-01 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10080180

## Citation

> US National Institutes of Health, RePORTER application 10080180, Ophthalmic Time-resolved Confocal Scanning Microfluorometer (1R43EY032002-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10080180. Licensed CC0.

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