Measurement of correlation between transmission and scattering during wound healing in hen corneas

Abstract

The aim of this work is to provide experimental data for corneal transparency and scattering to help create a more complete model of corneal transparency. The scattered light in 96 healing hen corneas was measured for three wavelengths by a scatterometer constructed in the Optics Laboratory (The University of Valladolid, Spain). With the help of mirrors and beamsplitters, the light from the three lasers is directed toward the cell containing the sample to be measured. The measured scattered light varies between six orders of magnitude. Corneal transmissivity, mean cosine of a scattering angle, and angular distribution of scattered light were all computed. The total transmitted light remained practically constant over a wide range of light values transmitted in a forward direction (direct transmissivity). The value of the mean cosine of the scattering direction is very close to the unit (g 4 0:98), even in corneas with high opacities. The behavior of g indicates that even damaged corneas evidence extremely small scattering, compared to other biological tissues. The transmission reduction of each cornea is related to an increase in scattered light. In all cases, scattered light is concentrated at very small angles. This behavior is acceptable in corneas that are healthy or which evidence small lesions, but remains in corneas that are severely injured.

Dynamic changes of the extracellular matrix during corneal wound healing

“…However, the transmittance values remained lower than control corneas, indicating that the stromal structure was not fully restored. Our device only measured direct transmissivity, which is related to an increase in scattered light (Mar et al, 2009) that we did not directly detect. The high level of scattering that remained in the severely injured corneas is probably due to the absence of the normal stromal architecture, which was partially replaced by the cells that appear in the healing process (Mar et al, 2009) and the lacunae or voids that appear in the stroma (McCally et al, 2007).…”

“…Our device only measured direct transmissivity, which is related to an increase in scattered light (Mar et al, 2009) that we did not directly detect. The high level of scattering that remained in the severely injured corneas is probably due to the absence of the normal stromal architecture, which was partially replaced by the cells that appear in the healing process (Mar et al, 2009) and the lacunae or voids that appear in the stroma (McCally et al, 2007). Direct measurement of light scattering during the wound healing process could support our transmittance data and give more information about stromal restoration after an alkali burn.…”

Analysis of the chicken retina with an adaptive optics multiphoton microscope

“…Furthermore, it can be easily bred and maintained in the laboratory from the day of hatching. Chickens have also served as animal models for the study of the cornea wound healing after refractive surgery treatments, such as LASIK, LASEK or PRK [ 10 – 13 ].…”

Detection of fine modifications in bulk corneal grafts based on backscattered light quantification

“…, where BRDF means Bidirectional Reflectance Distribution Function. The corneal graft is isotropic [33], so the measurements were made in the incident plane (φ=0). [8].…”