Application of catastrophe theory to corneal swelling.
Stromal swelling in human, cat, and rabbit cornea is biphasic, interpretable as an elementary cusp catastrophe proposed by Thom, with t* = log t and Q* = log Q (stromal charge Q, time t) as control parameters, and H0.5 (hydration H) as the state variable. A thermodynamic potential with two attractor regions, each with a local minimum, governs corneal stromal swelling. Transitions follow a 'saturation convention' whereby the second minimum is preferred upon availability. Corneal swelling is an example of a space-equivalent unfolding, where the transition plane moves in time. It is proposed that the transition plane coincides with the uncoupling of interfibrillary linkages or 'springs' in the corneal stroma, and is associated with a critical hydration of ca. 10 kg H2O per kilogram dry mass, and stromal charge ca. 1 x 10(-7) mol electrons.
Kwok
L S
LS
Department of Ophthalmology, Louisiana State University Medical Center, School of Medicine, New Orleans 70112-2234.
D000818:Animals; D001696:Biomechanical Phenomena; D001834:Body Water / Q000378:metabolism; D002415:Cats; D003319:Corneal Stroma / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D011509:Proteoglycans / Q000378:metabolism; D011817:Rabbits; D013816:Thermodynamics
D011509:Proteoglycans