Lid wiper epitheliopathy
In the following video, lissamine green dye highlights lid wiper epitheliopathy (LWE), which extends horizontally from the medial (right side of video frame) to the lateral canthus, and from the Marx line (sharp green border of superior staining) up to the tarsal sulcus fold. In some places, the stain extends onto the tarsus beyond the sulcus fold. Slit-lamp image obtained at 8X magnification.
Conjunctival flaps, areas of loose conjunctival tissue often located along an area of indentation, is best viewed with sodium fluorescein + cobalt blue filter + yellow wratten filter #12. The conjunctival region inner to the flap (towards limbus) may be irregular while the region outside the indentation is smooth. Conjunctival flaps resolve spontaneously with discontinuation of lens wear. Slit-lamp image obtained at 12X magnification.
Lid-parallel conjunctival folds
Lid-parallel conjunctival folds (LIPCOF) are sub-clinical folds present at the temporal regions of the inferior bulbar conjunctiva and parallel to the lid margin. Three clear folds can be seen in the following image: an inferior fold closer to the lid margin, a superior fold that seems to be causing a ‘kink’ in the conjunctival vessel at the medial end, and a fold just below the superior fold laterally. Slit-lamp image obtained at 32X magnification.
The following image shows conjunctival indentation in the superior region of the bulbar conjunctiva as an arc of sodium fluorescein stain. Through a slit-lamp, the outer border of the indentation may be seen as a slightly raised ridge of conjunctival tissue, and is usually best viewed with sodium fluorescein + cobalt blue filter + Yellow wratten filter #12 at mid-magnification (12X or 20X). Conjunctival indentation usually corresponds to the circumference of the contact lens region. Slit-lamp image obtained at 12X magnification.
This video, from the Centre for Contact Lens Research at the University of Waterloo, demonstrates corneal epithelial staining observed with a slit-lamp microscope under three conditions in succession, to highlight the benefits of using sodium fluorescein and a yellow barrier filter. The video shows staining under the following conditions:
1. Under white light
2. With sodium fluorescein instilled, viewed through a cobalt blue filter inserted over the source of illumination
3. With sodium fluorescein, viewed through a cobalt blue filter AND a yellow barrier filter (Wratten 12) in front of the observation system
This video, from the Centre for Contact Lens Research at the University of Waterloo, demonstrates an effective technique for expressing meibum from the lower lid. The glands in this video are blocked; when pressed, they express meibum with a pasty quality.