Which instrument is specifically used to enlarge the punctum?

The punctuation dilator is the instrument specifically designed to enlarge the punctum, the small opening of the tear duct. This instrument typically has a tapered end that can gently be inserted into the punctum, allowing it to be widened to facilitate tear drainage or to prepare for procedures such as punctal occlusion. The dilator is essential in various ophthalmic procedures, where accessibility to the tear drainage system is necessary.

The other instruments mentioned serve different purposes. A scalpel is primarily used for cutting and making incisions rather than for enlarging openings. A clamp is designed for grasping or holding tissue, and while it may be used in various surgical applications, it is not intended for altering the size of the punctum. A curette is typically used for scraping or removing tissue but does not serve the function of enlarging the punctum. This specialized function of the punctal dilator is why it is the correct choice for this question.