In Fincham’s test:
Glaucomatous halo remains intact
Halo due to immature cataract does not break into segments
Mucopurulent conjunctivitis does not produse halo
All of the above
Ans. Glaucomatous halo remains intact
- Fincham’s test is done using the staenopic slit to differentiate the colored haloes caused by cataract (lenticular) from that caused by glaucoma (corneal).
- Staenopic slit is moved across patient’s eye while the patient looks at a bright point source of light which gives rise to halo.
- The halo caused by cataract breaks into a fan the blades of which seem to move whereas the halo caused by glaucoma remains unchanged or just becomes a little faint.
- This is caused by peculiar disposition of the lens fibers which cause diffraction of light parallel to them.
- Mucopurulent conjunctivitis causes halos which disapper once the conjunctigitis resolves.