Eye Lens Crystallins: A Component of Intraocular Pseudoexfoliative Material

Abstract

Feeding experimental animals (19 pigs) with surplus sucrose and salt (NaCl) caused cataractous changes in lens tissue and triggered the formation of pseudoexfoliative material on the lens capsule. In the control animals (15 pigs) pseudoexfoliative material was absent. The avidin-biotin complex immunohistochemical method was applied to the pseudoexfoliative material obtained from 15 porcine experimental precataractous lenses and 1 spontaneously cataractous eye and revealed crystallins as a component of the intraocular pseudoexfoliative material. To prevent the development of both intraocular pseudoexfoliative material and crystallin-dependent glaucomatous changes in the trabecular meshwork of the eye, it is important to avoid any cataractogenic insult, including surplus sucrose and salt consumption, causing crystallin leakage from the lens.

Levels of Zinc, Iron, and Copper in Patients with Pseudoexfoliative Cataract

“…There are many studies related to pathogenesis of PEX. Ve roman et al reported that excessive sucrose and salt consumption can trigger crystallin leakage from the lens and PEX formation (11). Schlötzer-Schrehardt et al reported that the zinc signal in PEX fibrils may be associated with the presence of zinc-dependent enzymes, such as matrix metalloproteinases, which have been shown to accumulate within PEX material by immunohistochemistry and have been suggested to play a role in the aberrant matrix metabolism (23).…”

“…The zinc level in serum had no significant differences between the two groups (p=0.823, p=0.472, re s p e c t i v e l y ) . March 27, 2006 Recently, electron microscopic and biochemical studies have demonstrated composition of PEX material (8)(9)(10)(11). Some authors have shown the level of trace elements in cataractous lenses.…”

Growth Factors, Oxidative Damage, and Inflammation in Exfoliation Syndrome

“…The porcine model developed the material after induction of cataracts with a high sucrose diet and the material was shown to contain crystallins. 13 The genetic mouse model, the Lyst mouse, exhibited in addition an iris transillumination phenotype characteristic of XFG. 14 Interestingly, the material stained with anti-FBN1 antibody.…”

Animal Models of Exfoliation Syndrome, Now and Future

“…Extremely few publications have studied animal models of XFS, and to our knowledge, only 2 animal models have been reported. 27, 28 There are no reports of models with all of the features of XFS with XFG. The lack of animal models has been suggested to reflect the typical occurrence of XFS at old ages, with the belief that model species do not live long enough to develop the condition.…”

“…27 The authors fed pigs a high sucrose, high salt diet to induce cataracts. They reasoned that cataracts are common in XFS and that mature cataracts shed exfoliative material.…”