Neostigmine, an acetylcholinesterase inhibitor, has been the traditional reversal agent of choice. It acts by increasing acetylcholine levels at the synapse, thus facilitating skeletal muscle function reversal. However, the increased acetylcholine levels in other places lead to side effects like bradycardia, bronchoconstriction, and sialorrhoea. To counteract them, an anticholinergic agent like glycopyrrolate or atropine is co-administered. However, they themselves have their side effects of tachycardia, drying of secretions, and gastric paresis.

Sugammadex, a modified cyclodextrin, is a newer reversal agent. By encapsulating steroidal NMBAs such as vecuronium and rocuronium, it facilitates their rapid clearance from the body. Studies have shown that reversal using sugammadex is associated with lesser residual paralysis and hence faster recovery. Also, it is devoid of the cholinergic or anticholinergic side effects that coadministration of neostigmine and glycopyrrolate is associated with .

While the systemic side effects of these reversal agents are well documented, there has not been adequate research on their effects on pupils. Pupillary functions are reflective of autonomic nervous system activity, and alterations in their size indicate underlying pharmacological effects or complications. Understanding how neostigmine or sugammadex affects pupil size and function can offer us an insight into bettering postoperative monitoring and assessing patient cognitive functions through scores like the FOUR or GCSP score, both of which use pupillary function as a component.

As far as sugammadex is concerned, though it is well tolerated, it is not devoid of side effects. Side effects such as bradycardia, hypotension, and even anaphylaxis have been associated with sugammadex. Prompt recognition of these side effects is essential for optimum management and patient well being.

This thesis aims to compare the effects of neostigmine and sugammadex on postoperative pupillary function in patients undergoing elective surgery under general anesthesia. By elucidating the differential impacts of these agents, the study seeks to better our understanding of the physiological effects of these agents and contribute to optimizing perioperative care, especially in settings like neurosurgical cases where the assessment of postoperative pupillary function is of importance, with it being a part of several cognitive assessment scores like GCS-P and FOUR score.