Related Experiment Video
Updated: May 17, 2026
Full-Field Optical Coherence Microscopy for Histology-Like Analysis of Stromal Features in Corneal Grafts
Published on: October 21, 2022
Smoothness assessment of corneal stromal surfaces
Anca Marian1, Ossama Nada2, François Légaré1
1From the Maisonneuve-Rosemont Hospital Research Center (Marian, Nada, Brunette, Costantino), the Department of Mathematics and Statistics (Meunier, Roy), University of Montreal, and the Department of Ophthalmology (Meunier, Brunette, Costantino), University of Montreal, Montreal, Quebec, and the Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications (Marian, Légaré, Vidal), Varennes, Quebec, Canada.
Purpose:
To assess the accuracy of the scanning electron microscopy (SEM) and present alternative approaches to quantify surface roughness based on numerical analysis.
Setting:
Department of Ophthalmology, Maisonneuve-Rosemont Hospital, University of Montreal, Montreal, Quebec, Canada.
Design:
Experimental study.
Methods:
Lamellar stromal cuts were performed on human corneas using a femtosecond laser or a microkeratome. The photodisrupted stromal surfaces were processed for SEM, and images were acquired at ×1000 magnification. First, images were evaluated by independent observers. Second, images were analyzed based on first-order and second-order statistics of gray-level intensities. Third, 3-dimensional (3-D) surface reconstructions were generated from pairs of SEM images acquired at 2 angles.
Results:
Results show that traditional assessment of roughness based on evaluating SEM images by independent observers can be replaced by computer-image texture analysis; an algorithm was developed to avoid subjective and time-consuming observations. The 3-D reconstructions allowed additional characterization of surface properties that was not possible with SEM images alone. Significant fluctuations in surface height were lost, although they could be retrieved using 3-D reconstructions.
Conclusions:
Image texture analysis allowed objective and repeatable assessment of stromal surface roughness; however, full assessments of surface-height fluctuations required 3-D reconstruction. These complementary methodologies offer a more comprehensive assessment of corneal surface roughness in clinical applications.
