Fig 2. Superior and inferior eyelids.

(A) Panoramic view of the superior conjunctiva created using 51 overlapping images of an H&E-stained paraffin section. A physical tear in the mucosa that occurred during processing is marked by an *. Bar = 1000 μm. (B) Inferior conjunctiva panoramic composite formed from 62 images. Large adipose pads (AP) are present in the center of the marginal zone of both the superior and inferior conjunctiva. The arrows labeled C through H on Figs 2A and 2B show the approximate location of the high power magnification views shown in Figs 2C through 2H. Bar = 1000 μm. (C) Distal orbital zone of the superior conjunctiva. Goblet cells (black arrows) are interspersed amongst epithelial cells with cytofilia extensions (green arrows) similar to those more extensively expressed in the third eyelid. Bar = 10 μm. (D) Proximal orbital zone of superior conjunctiva. The goblet cells (black arrows) in this region are intermixed with columnar epithelial cells that lack the cytofilia seen in more distal regions. Bar = 10 μm. (E) Marginal zone of the superior conjunctiva. The thick stratified squamous epithelium has a thick keratinized coat. Melanosomes can be observed in cells throughout the full thickness of the epithelium and into the keratinized layer. Bar = 10 μm. (F) The orbital zone of the inferior conjunctiva is typically more folded than the superior region. Plump goblet cells (black arrows) filled with mucous granules are scattered throughout the epithelium. Bar = 10 μm. (G) The plate region of the inferior conjunctiva is a stratified cuboidal epithelium with fewer goblet cells than seen in the orbital zone. It was not unusual to see granulocytes (green arrows) with eosinophilic granules within the epithelial layer or in the connective tissue just below it. Bar = 10 μm. (H) In the distal quarter of the marginal zone, the epithelium remains stratified squamous but is no longer keratinized as typically seen in the proximal marginal zone. The number of melanosomes present in the epithelium begins decreasing as the epithelium gets closer to the plate region. Goblet cells (black arrows) can be found in this region but are not generally found more proximally. Granulocytes (green arrows) are also found in the distal marginal zone but they are not typically as abundant as they are in the plate region. Bar = 10 μm.