Purpose. The lack of assessment and thus control of the hydration of the ablation site, is believed to he the cause of several undesired side-effects associated with cornea ablation. The aim of (his study was to quantify in-vivo the water distribution across the rabbit cornea as function of time after abrasion. Methods. A non-invasive scanning confocal Raman spectroscopy (SCRS) technique (25 mW Argon, Is probing time, SPKX500M, axial resolution 50 um) was used to assess the water content (Raman intensity ratio of water-peak/protein-peak) of consecutive layers along the optical axis of the cornea with scan-steps of 50 HID. Two regions were studied closely: the superficial 100 Jim (A) and the most posterior UK) u.m (P) of stroma. This technique was validated and calibrated in 9 m-vitro rabhil eyes, by quantifying the relationship between pachymetric- and SCRSassessed total corncal hydration (H). Eight corneas of NZW rabbits were abraded in-vivo, and the time dependenf changes in hydration were assessed for H, A and P. Results. Calibration revealed a linear relationship between pachyinelric- and SCRS-assessed H, invitrti (SI>=0.01, R-=0.94) as well as in-vivo before abrasion (SI)=0.10, R3=0.77). In agreement with current literature, H, A and P show different non-linear time-dependencies after abrasion. A correlated better with H than P <A=[0.72±0.()8]/J. R2=0.88. and /'=| 1.56±0.i 1 ]//, R:=<>.68), while the linear correlation between pachymetric- and SCRSassessed H after abrasion was reasonable (SD=().l 1, R2=0.87). Conclusion. Our results suggest that SCRS can be used to quantify the expected time-dependent changes of the axial corneal hydration gradient after abrasion m-vivo. This may render future applications of this technique possible in the assessment and control of corneal hydration.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience