In congenital nasolacrimal duct obstruction (CNLDO), the Jones dye test is used to evaluate lacrimal drainage. A positive Jones I test (fluorescein appearing at the nose within 5 minutes) indicates:

• A Complete obstruction of the nasolacrimal duct
• B Canalicular obstruction with normal duct patency
• C Patent lacrimal drainage system with functional outflow ✓
• D Punctal agenesis

Explanation

The Jones dye test I assesses functional lacrimal drainage: fluorescein dye is instilled into the conjunctival sac, and a cotton swab at the inferior meatus of the nose is checked for dye recovery after 5 minutes. A positive result (dye at nose) indicates a physiologically and anatomically patent lacrimal drainage system. A negative Jones I test suggests either obstruction or poor functional pump (marginal block). Jones II test is then performed: residual dye is irrigated out, and saline is flushed through; recovery at the nose confirms partial obstruction (system patent under pressure but not by capillary action/lacrimal pump).

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.