Related Experiment Video
Updated: Apr 13, 2026

Puncture-Induced Iris Neovascularization as a Mouse Model of Rubeosis Iridis
Published on: March 8, 2018
Supernumerary punctum: an unusual case of seeing double
1École d'Optométrie, Université de Montréal, Montréal, Québec, Canada. etty.bitton@umontreal.ca.
Abstract:
Supernumerary punctum is an under-reported congenital anomaly, in which there is more than one lacrimal punctum. Although usually asymptomatic, supernumerary puncta have been reported to cause dry eye or epiphora (excessive tearing) and should be included in their differential diagnosis. Tearing is often associated with dry eyes and can lead to discontinuation of contact lens wear. A comprehensive evaluation of the causes of tearing may uncover other contributory factors of epiphora. This case report highlights unilateral inferior double puncta in an otherwise asymptomatic patient. Due to increased evacuation of tears in the affected eye, manual occlusion of the puncta was advocated to allow topical medication to be more efficacious.
Related Concept Videos
Bone Markings
Articulating Projections
Articulating projections are found where two bones meet to form a joint. These structures are usually found at the ends of bones. The largest articulation is a rounded projection called the head, supported by a narrow neck at the ends of...
Porin Insertion in the Outer Mitochondrial Membrane
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
The Tongue and Taste Buds
Pinocytosis
Pinocytosis ("cellular drinking") is one of three main types of...
Pinocytosis
Types of Membrane Protrusions
The microvilli, an example of stable protrusions, are finger-like projections...

