Abstract
Purpose: :
To determine the functional and histo-pathological changes of Bruch’s membrane and adjacent retinal pigment epithelium(RPE)-chorioretinal complex in a chick animal model.
Methods: :
White Leghorn chicks were raised for 2, 4, 6 and 8 weeks. Myopia was induced in the right eye of first-day chick by wearing translucent goggles. Histopathologic studies were performed on equatorial and posterior pole areas by light microscopy and electron microscopy. Immunohistochemical study was performed to detect the elastic membrane. Cultured chick RPE cell binding to trephined Bruch’s membrane-choroid-sclera eye cup buttons were measured by MTT essay to determine the reattachment rates.
Results: :
There were no morphological changes in the equatorial and posterior pole areas in the 2-, 4-, and 6-weeks groups. Elastic membrane rupture was found in six out of eight chicks by 8 weeks in the equatorial area but not the posterior pole. Immunohistochemical study showed faint staining of the elastic membrane in the 8-week-old eyes compared to that in the control group. The reattachment rates of chick RPE to equatorial Bruch’s membrane were 82.3 ± 4.5% in the control group, and 78 ± 4.1%, 52.4 ± 8.3% ( P < 0.05), 43.8 ±3.4 (P<0.05), and 28.6 ± 6.5% (P<0.05) respectively in 2-, 4-, 6- and 8-weeks groups.
Conclusions: :
Rupture of the elastic membrane, the first sign of Bruch’s membrane degeneration was seen at 8 weeks in White Leghorn chicks, and the reattachment efficiency of RPE to Bruch’s membrane was decreased beginning 4 weeks after deprivation. Our results indicated that the degenerative changes in the RPE binding capacity-related extracellular matrix proteins on Bruch’s membrane may serve as a chick animal model in the study of complications of pathological myopia.
Keywords: myopia • Bruch's membrane • retinal pigment epithelium