Purpose: To use digital image processing analysis techniques as a clinical tool for measuring the normal palpebral fissure. Methods: 70 palpebral fissure images of 23 males and 47 females with ages ranging from 10 to 60 years were analyzed. The images were captured with a CCD camera and transferred to a Macintosh computer. Using the NIH software, the following variables were measured: 1) area, 2) length, 3) height and angle between the medial and lateral canthi, 4) upper and lower eyelid curvatures 5) position of the highest point of the upper contour and the lowest point of the lower contour relative to the palpebral fissure midline. Results: The mean values obtained for the length, height and vertical position of the lateral canthus relative to medial canthus agree well with normative values found in the literature. Variables that have never been quantified as the upper and lower eyelid contour and palpebral fissure area were easily measured. Conclusions: The digital image processing is a simple method for the 2-dimensional analysis of the palpebral fissure and allows refined measurements of the fissure morphology.
Eyelid diseases; Eyelids; Image processing, computer-assisted
