Regional and zonal variations in the sulfation patterns of chondroitin sulfate in normal equine corneal stroma

Abstract

Distribution of deltaDi6S/deltaDi4S values follows a gradient across the healthy equine cornea, being smallest in the deep and middle zones of the central region and the deep zone of the peripheral region. Regional and zonal differences in the distribution of stromal deltaDi6S and deltaDi4S may influence the role of glycosaminoglycans in health, disease, and wound repair of the equine cornea.

Immune‐mediated keratitis in horses: 19 cases (1998–2004)

“…Or the differential locations of inflammation may represent the immune system recognition of separate types of antigens at each location of the cornea (e.g. differing collagen and glycosaminoglycans types at various corneal levels) 37 …”

“…differing collagen and glycosaminoglycans types at various corneal levels). 37 Furthermore, the various clinical diseases commonly lumped into the syndrome of 'equine recurrent uveitis' may have a similar pathogenesis to IMMK. For example, equine recurrent uveitis that has predominantly anterior segment involvement may be a manifestation of antigen recognition within the iris and ciliary body, while equine recurrent uveitis that has predominantly posterior segment involvement may be the result of antigen recognition in the retina or choroid.…”

Aqueous humor and plasma concentrations of ciprofloxacin and moxifloxacin following topical ocular administration in ophthalmologically normal horses

“…7 The increased corneal thickness of horses (900 µm) 26 versus that of humans (600 µm), 27 as well as the varied corneal glycosaminoglycan composition in horses, 28 may also impact corneal permeability and drug movement. Tear film proteins, which vary among species, affect drug bioavailability by readily binding certain drugs and making them unavailable for absorption, whereas the tear film pH may buffer acidic or alkaline drug formulations, altering the ionization status and relative lipophilicity.…”

Differential diagnosis and management of corneal ulceration in horses, part 1

“…The ratio of chondroitin 6-sulfate to chondroitin 4-sulfate is lower in the deep and mid stromal layers than in the superficial layers, as well as in the peripheral versus central zones of the equine cornea. Chondroitin 4-sulfate has a greater water-holding capacity than chondroitin 6-sulfate, so this glycosaminoglycan-sulfation distribution has consequences for corneal oedema in different regions or depths of the cornea (Biros and others 2002). …”