Which of the following best describes deep corneal neovascularization?

Deep corneal neovascularization is characterized by the presence of inflamed blood vessels that invade the corneal stroma. This condition typically occurs in response to chronic insult, such as hypoxia, inflammation, or injury, leading to new blood vessels growing into the normally avascular corneal tissue. The growth of these vessels is often accompanied by inflammation, making option C the best descriptor of deep corneal neovascularization.

While the other options touch on various aspects of corneal health and neovascularization, they do not accurately encapsulate the essence of deep corneal neovascularization. For instance, neovascularization does not originate from the epithelial layer, as it is primarily a change involving the deeper stroma of the cornea. Additionally, while neovascularization itself may not always be directly visible without appropriate imaging techniques, it can be observed in certain cases, particularly when the cornea becomes edematous or there is associated inflammation. The notion that deep corneal neovascularization often improves quickly with treatment is also misleading, as it can take time and depends on addressing the underlying cause. Thus, option C effectively captures the defining characteristics of this condition.