Six weeks after uneventful LASIK, a 30-year-old complains of severe dryness, foreign body sensation and fluctuating vision. Schirmer test is reduced and corneal staining is present. The principal mechanism responsible is:
- A Severing of corneal stromal nerves during flap creation causing decreased afferent reflex tearing ✓
- B Permanent destruction of goblet cells by the excimer laser plume
- C Obstruction of meibomian gland orifices by the suction ring
- D Allergic reaction to residual riboflavin retained in the interface
Correct answer: A. Severing of corneal stromal nerves during flap creation causing decreased afferent reflex tearing
Explanation
LASIK cuts through the subbasal nerve plexus when the flap is raised, reducing corneal sensory input and thereby blunting the trigeminal-driven lacrimal reflex tear secretion. Dry eye is consequently the commonest side effect after LASIK, typically worst in the first months, and is more severe than after surface ablation because PRK spares deeper nerves. Goblet cells are not destroyed by the laser, riboflavin is not used in LASIK, and suction ring pressure does not obstruct meibomian glands.
Reference: Yanoff and Duker, Ophthalmology, 5th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.