THE INTERPHOTORECEPTOR MATRIX MEDIATES PRIMATE RETINAL ADHESION

Objective: To assess the participation of cone matrix sheaths, which are domains of the cone photoreceptor-associated interphotoreceptor matrix that extend from the neural retina to the surface of the retinal pigment epithelium (RPE), in retinal adhesion. Methods: Monkey and human retinas were partially peeled from the RPE, and the tissues were examined by lectin histochemistry to determine the effects of physical separation on the cone matrix sheath. Results: A firm attachment of cone matrix sheaths to both the RPE and the neural retina that was strong enough to cause detachment of sheets of RPE cells from Bruch's membrane or tearing of the sheaths as a result of retinal peeling was observed. Cone matrix sheaths can stretch considerably and contract following tearing. Their integrity was compromised rapidly after the first postmortem minute. Conclusion: Cone matrix sheath glycoconjugates are likely to play a major role in mediating retinal adhesion by forming a molecular bridge betwen the neural retina and the RPE.