Autologous Transplantation of Retinal Pigment Epithelium and Partial-thickness Choroid after Mechanical Debridement of Bruch's Membrane in the Rabbit
Yuntao Hu 1,
Taoran Zhang 1,
Jianguo Wu 1,
Ying Li 1,
Xinrong Lu 1,
Fang Qian 1,
Zhengqin Yin 2,
and
Zhizhong MA 3*
1 Peking University Eye Center, Peking University Third Hospital, Beijing, China
2 Southwest Eye Hospital, Third Military Medical University, Chongqing, China
3 Peking University Eye Center, Peking University Third Hospital, No. 49 Hua Yuan Bei Lu, Haidian District, Beijing, 100083, China
* To whom correspondence should be addressed. E-mail: puh3_yk{at}bjmu.edu.cn.
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Abstract |
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PURPOSE. An improved translocation technique for autologous retinal pigment epithelium (RPE) transplantation is presented. The graft consists of a sheet of a partial-thickness choroid together with RPE attached.
METHODS. Twenty-seven pigmented rabbits were used in this study. After mechanical debridement of Bruch's membrane, partial-thickness RPE-choroid sheets were transplanted onto the subretinal space in 25 rabbits. The animals were examined by fundus photographs and fluorescein angiographs and were sacrificed postoperatively at 1, 2, 4, 12, and 24 weeks. Eye cups containing the graft were examined by light microscopy and immunohistochemistry. In addition, 2 partial-thickness RPE-choroid sheets were analyzed by transmission electron microscopy (TEM).
RESULTS. TEM revealed that the partial-thickness RPE-choroid graft consisted of RPE cells, Bruch's membrane, choriocapillaries, and ruptured middle vessels. The thickness of the graft was approximately 50-60µm. Fluorescein angiography revealed neither fluorescein leakage nor staining in the graft at either early or late phase. Light microscopy revealed that in 17 experiments in which the graft survived, the neural retina remained intact; however, in 8 experiments with unsuccessful grafts, the neural retina degenerated. The surviving graft showed revascularization and monolayered RPE cells. Furthermore, in sections in which the neural retina over the graft remained intact, all RPE cells in the graft and rhodopsin in photoreceptor outer segments were positively labeled with anti-cellular retinaldehyde-binding protein antibodies and anti-opsin antibodies, respectively.
CONCLUSIONS. A partial-thickness RPE-choroid graft shows improved integration with the host choroid and photoreceptors. This technique has the potential to be a treatment for age-related macular degeneration.
Key Words:
age-related macular degeneration, retinal pigment epithelium, transplantation, surgery
