Quantification of chick lens alphaA- and delta-crystallins in experimentally induced ametropia.

Abstract

PURPOSE:

The role of the lens in experimentally induced ametropia is not known. A recent study of the chick lens demonstrated optical quality deterioration with the induction of refractive errors, without alteration in lens morphology, size or shape. A change in lens gradient of refractive index (which is dependent on alpha-, beta-, and delta-crystallin concentration and arrangement), could underlie this observation. The purpose of this work was to quantify the concentrations of alphaA- and delta-crystallin in lenses from chick eyes with induced high myopia or hyperopia.

METHODS:

White Leghorn chicks were unilaterally fitted on the day of hatching either with translucent plastic goggles to induce form-deprivation myopia (n=21) or with +15 D defocus goggles to induce hyperopia (n=14). The ungoggled contralateral eyes were used as controls. The chicks were refracted twice, once on the day of hatching and again seven days later, using streak retinoscopy. On day 7 chicks were sacrificed, lenses decapsulated, and soluble proteins were isolated. Western blot assays were optimized and used to assess crystallin concentration.

RESULTS:

Analysis revealed no significant difference in alphaA- or delta-crystallin concentration in lenses from eyes induced with form-deprivation myopia and hyperopia as compared to their respective control eyes. Analysis of the difference in medians of delta-crystallin between the control and treated groups of the myopia and hyperopia experiments revealed significance (p=0.030).

CONCLUSIONS:

This study suggests that with the induction of ametropia, the increased lens spherical aberration previously noted is not due to a change in the absolute concentration of lens alphaA- or delta-crystallin. However, results suggest that the myopic and hyperopic treatments had different effects on lens delta-crystallin concentration. Further investigation is necessary to expand the current knowledge of the role played by the lens in experimental ametropia.

• Authors: Sophia Zaidi, Michelle Senchyna, Jacob G Sivak
• Journal: Molecular vision (Mol Vis) Vol. 8 Pg. 472-6 (Dec 19 2002) ISSN: 1090-0535 [Electronic] United States
• PMID: 12500175 (Publication Type: Journal Article)

Chemical References

• Antibodies, Monoclonal
• alpha-Crystallin A Chain
• delta-Crystallins

Topics

• Animals
• Animals, Newborn
• Antibodies, Monoclonal
• Blotting, Western
• Chickens
• Electrophoresis, Polyacrylamide Gel
• Hyperopia (etiology, metabolism, pathology)
• Immunoblotting
• Lens, Crystalline (metabolism)
• Models, Animal
• Myopia (etiology, metabolism, pathology)
• Refraction, Ocular
• Sensory Deprivation
• alpha-Crystallin A Chain (metabolism)
• delta-Crystallins (metabolism)