In canalicular blockage, which is true about jones test findings?
Jones dye testing 1. Dye testing is indicated only in patients with suspected paial obstruction of the drainage system 2. The primary test differentiates paial obstruction of the lacrimal passages and lacrimal pump failure from primary hypersecretion of tears. 3. A drop of 2% fluorescein is instilled into the conjunctival sac of one eye only. After about 5 minutes, a cotton-tipped bud moistened in local anaesthetic is inseed under the inferior turbinate at the nasolacrimal duct opening. 4. The results are interpreted as follows: Positive: fluorescein recovered from the nose indicates patency of the drainage system. Watering is due to primary hypersecretion and no fuher tests are necessary. 5. Negative: No dye recovered from the nose indicates a paial obstruction (site unknown) or failure of the lacrimal pump mechanism. In this situation the secondary dye test is performed immediately. 6. The secondary test identifies lacrimal pump failure or the probable site of paial obstruction, on the basis of whether the topical fluorescein instilled for the primary test entered the lacrimal sac. Topical anaesthetic is instilled and any residual fluorescein washed out from the conjunctival fornix. The drainage system is then irrigated with a cotton bud under the inferior turbinate 7. Positive: fluorescein-stained saline recovered from the nose indicates that fluorescein entered the lacrimal sac, thus confirming functional patency of the upper lacrimal passages. Paial obstruction of the nasolacrimal duct distal to the sac is inferred. 8. Negative: unstained saline recovered from the nose indicates that fluorescein did not enter the lacrimal sac. This implies upper lacrimal (punctal or canalicular) dysfunction, which may be due to paial physical occlusion and/or pump failure.
First test positive second test negative
First test negative second test positive
Both first and second tests are positive
Both first and second tests are negative
Ophthalmology Q Bank