Non-invasive in-vivo assessment of corneal dehydration in the rabbit using confocal Raman spectroscopy

R. J. Erckens, N. J C Bauer, W. F. March, F. H M Jongsma, F. Hendrikse, Massoud Motamedi

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Purpose. Maintaining adequate hydration of the cornea is essential for visual acuity but heretofore accurate measurements of corneal hydration in-vivo have been unavailable. Using a confocal Raman spectroscopy (Conforam) system we studied hydrational changes of the in-vivo rabbit cornea after instillation of a dehydrating agent. Methods. The Conforam is a fiber based, diffraction limited probe with a long working distance for free mechanical movement and a CCD array allowing rapid scanning (< 10s) and low laser power (< 25 mW). The 514.5 nm line of a CW Argon-ion laser was used as excitation light. Three NZW rabbits were investigated. Axial cornea scans in the higher spectral range (2634-3820 cm-1) were taken for the whole corneal thickness. Scans before and after instillation of the dehydrating agent Muro-128 (5% NaCl Ophthalmic Ointment) were compared in the same eye, using the OH- and CH-peaks to calculate a OH/CH ratio as a measure for corneal hydration. Statistical analysis was performed using the Student's t-test. Results. The average OH/CH ratio was 60.5 (SD=6.8) in non-treated eyes and 52.4 (SD=2.9) in NaCl treated eyes. There was a statistical significant difference (p<0.05) between the treated and non-treated cornea. A high enough spectral S/N ratio was obtained during these experiments. However, the NaCl ointment obscured the CH-peak in the higher spectral region at superficial cornea scans. Conclusion. With our Confocal Raman Spectroscopy probe it is possible to assess the relative decrease in corneal hydration of healthy living rabbits after a dehydrating agent is applied. 5% NaCl decreases corneal hydration dramatically.

Original languageEnglish (US)
JournalInvestigative Ophthalmology and Visual Science
Volume37
Issue number3
StatePublished - Feb 15 1996

Fingerprint

Raman Spectrum Analysis
Dehydration
Cornea
Rabbits
Ointments
Gas Lasers
Visual Acuity
Lasers
Students
Light

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Non-invasive in-vivo assessment of corneal dehydration in the rabbit using confocal Raman spectroscopy. / Erckens, R. J.; Bauer, N. J C; March, W. F.; Jongsma, F. H M; Hendrikse, F.; Motamedi, Massoud.

In: Investigative Ophthalmology and Visual Science, Vol. 37, No. 3, 15.02.1996.

Research output: Contribution to journalArticle

Erckens, R. J. ; Bauer, N. J C ; March, W. F. ; Jongsma, F. H M ; Hendrikse, F. ; Motamedi, Massoud. / Non-invasive in-vivo assessment of corneal dehydration in the rabbit using confocal Raman spectroscopy. In: Investigative Ophthalmology and Visual Science. 1996 ; Vol. 37, No. 3.
@article{d4ffb504e2f74f789ff987ebd903ee34,
title = "Non-invasive in-vivo assessment of corneal dehydration in the rabbit using confocal Raman spectroscopy",
abstract = "Purpose. Maintaining adequate hydration of the cornea is essential for visual acuity but heretofore accurate measurements of corneal hydration in-vivo have been unavailable. Using a confocal Raman spectroscopy (Conforam) system we studied hydrational changes of the in-vivo rabbit cornea after instillation of a dehydrating agent. Methods. The Conforam is a fiber based, diffraction limited probe with a long working distance for free mechanical movement and a CCD array allowing rapid scanning (< 10s) and low laser power (< 25 mW). The 514.5 nm line of a CW Argon-ion laser was used as excitation light. Three NZW rabbits were investigated. Axial cornea scans in the higher spectral range (2634-3820 cm-1) were taken for the whole corneal thickness. Scans before and after instillation of the dehydrating agent Muro-128 (5{\%} NaCl Ophthalmic Ointment) were compared in the same eye, using the OH- and CH-peaks to calculate a OH/CH ratio as a measure for corneal hydration. Statistical analysis was performed using the Student's t-test. Results. The average OH/CH ratio was 60.5 (SD=6.8) in non-treated eyes and 52.4 (SD=2.9) in NaCl treated eyes. There was a statistical significant difference (p<0.05) between the treated and non-treated cornea. A high enough spectral S/N ratio was obtained during these experiments. However, the NaCl ointment obscured the CH-peak in the higher spectral region at superficial cornea scans. Conclusion. With our Confocal Raman Spectroscopy probe it is possible to assess the relative decrease in corneal hydration of healthy living rabbits after a dehydrating agent is applied. 5{\%} NaCl decreases corneal hydration dramatically.",
author = "Erckens, {R. J.} and Bauer, {N. J C} and March, {W. F.} and Jongsma, {F. H M} and F. Hendrikse and Massoud Motamedi",
year = "1996",
month = "2",
day = "15",
language = "English (US)",
volume = "37",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "3",

}

TY - JOUR

T1 - Non-invasive in-vivo assessment of corneal dehydration in the rabbit using confocal Raman spectroscopy

AU - Erckens, R. J.

AU - Bauer, N. J C

AU - March, W. F.

AU - Jongsma, F. H M

AU - Hendrikse, F.

AU - Motamedi, Massoud

PY - 1996/2/15

Y1 - 1996/2/15

N2 - Purpose. Maintaining adequate hydration of the cornea is essential for visual acuity but heretofore accurate measurements of corneal hydration in-vivo have been unavailable. Using a confocal Raman spectroscopy (Conforam) system we studied hydrational changes of the in-vivo rabbit cornea after instillation of a dehydrating agent. Methods. The Conforam is a fiber based, diffraction limited probe with a long working distance for free mechanical movement and a CCD array allowing rapid scanning (< 10s) and low laser power (< 25 mW). The 514.5 nm line of a CW Argon-ion laser was used as excitation light. Three NZW rabbits were investigated. Axial cornea scans in the higher spectral range (2634-3820 cm-1) were taken for the whole corneal thickness. Scans before and after instillation of the dehydrating agent Muro-128 (5% NaCl Ophthalmic Ointment) were compared in the same eye, using the OH- and CH-peaks to calculate a OH/CH ratio as a measure for corneal hydration. Statistical analysis was performed using the Student's t-test. Results. The average OH/CH ratio was 60.5 (SD=6.8) in non-treated eyes and 52.4 (SD=2.9) in NaCl treated eyes. There was a statistical significant difference (p<0.05) between the treated and non-treated cornea. A high enough spectral S/N ratio was obtained during these experiments. However, the NaCl ointment obscured the CH-peak in the higher spectral region at superficial cornea scans. Conclusion. With our Confocal Raman Spectroscopy probe it is possible to assess the relative decrease in corneal hydration of healthy living rabbits after a dehydrating agent is applied. 5% NaCl decreases corneal hydration dramatically.

AB - Purpose. Maintaining adequate hydration of the cornea is essential for visual acuity but heretofore accurate measurements of corneal hydration in-vivo have been unavailable. Using a confocal Raman spectroscopy (Conforam) system we studied hydrational changes of the in-vivo rabbit cornea after instillation of a dehydrating agent. Methods. The Conforam is a fiber based, diffraction limited probe with a long working distance for free mechanical movement and a CCD array allowing rapid scanning (< 10s) and low laser power (< 25 mW). The 514.5 nm line of a CW Argon-ion laser was used as excitation light. Three NZW rabbits were investigated. Axial cornea scans in the higher spectral range (2634-3820 cm-1) were taken for the whole corneal thickness. Scans before and after instillation of the dehydrating agent Muro-128 (5% NaCl Ophthalmic Ointment) were compared in the same eye, using the OH- and CH-peaks to calculate a OH/CH ratio as a measure for corneal hydration. Statistical analysis was performed using the Student's t-test. Results. The average OH/CH ratio was 60.5 (SD=6.8) in non-treated eyes and 52.4 (SD=2.9) in NaCl treated eyes. There was a statistical significant difference (p<0.05) between the treated and non-treated cornea. A high enough spectral S/N ratio was obtained during these experiments. However, the NaCl ointment obscured the CH-peak in the higher spectral region at superficial cornea scans. Conclusion. With our Confocal Raman Spectroscopy probe it is possible to assess the relative decrease in corneal hydration of healthy living rabbits after a dehydrating agent is applied. 5% NaCl decreases corneal hydration dramatically.

UR - http://www.scopus.com/inward/record.url?scp=7144246898&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=7144246898&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:7144246898

VL - 37

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 3

ER -