Which statement best describes the purpose of fluorescein staining in ocular surface assessment?

• A. Detect epithelial defects and multifocal epithelial cell loss
• B. Assess intraocular pressure
• C. Visualize posterior segment
• D. Measure tear production

Answer: (A)

Fluorescein staining reveals disruptions in the corneal and conjunctival epithelium by pooling in areas where the epithelial barrier is compromised. Under cobalt blue light, these defects glow bright green, making it easy to detect epithelial ulcers, erosions, or multifocal punctate epithelial loss. This technique directly assesses surface integrity and helps gauge the extent and pattern of surface disease, guiding management. It isn’t used to measure intraocular pressure, visualize the posterior retina or choroid, or quantify tear production—that requires tonometry, ophthalmoscopy, or tear-film testing, respectively. To perform it, a drop is applied and the eye is rinsed or blinked to spread the dye, then examined under blue light to identify epithelial abnormalities.