What type of surgery requires probes and dilators to open obstructed canals?

The type of surgery that requires probes and dilators to open obstructed canals is lacrimal surgery. This procedure is specifically designed to address issues related to the tear drainage system, which includes the lacrimal gland, puncta, canaliculi, and nasolacrimal duct. When there is an obstruction in this system, it can lead to excessive tearing or infections due to improper drainage of tears.

During lacrimal surgery, probes and dilators are essential tools used to navigate and clear these obstructions. Probes can be inserted into the puncta and through the canaliculi to find and open the blocked areas, while dilators help to gently enlarge these passages for better access and irrigation.

In contrast, cataract surgery focuses on removing the cloudy lens from the eye, corneal transplant involves replacing a damaged cornea with healthy donor tissue, and retinal surgery addresses issues related to the retina, none of which require the use of probes and dilators to clear obstructed canals. Therefore, lacrimal surgery is uniquely characterized by its need for these specific instruments to restore proper tear drainage.