Kam KW, et al. - Two sampling methods, the grid and sectoral methods, were designed to provide more precise detection of focal corneal scar changes with time following pterygium excision with the Pentacam imaging system. In this retrospective study of 30 patients who underwent primary pterygium excision with adjuvant topical mitomycin-C application, they applied Grid and sectoral methods to sample density changes (in grayscale units, GSU) over the scarred areas as well as the clear pole of the same cornea. Compared to conventional total-diameter average densitometry, the novel approach to monitoring corneal density changes, using the grid or sectoral sampling methods, appeared enhancing the power in monitoring density changes in corneal scars.