Type VII Collagen in the Human Accommodation System: Expression in Ciliary Body, Zonules, and Lens Capsule.

Purpose To investigate intraocular expression of COL7A1 and its protein product type VII collagen, particularly at the accommodation system. Methods Eyes from 26 human adult donors were used. COL7A1 expression was analyzed in ex vivo ciliary epithelium by microarray. Type VII collagen distribution was examined by Western blot analysis, immunohistochemistry. and immuno-electron microscopy. Results COL7A1 is expressed by pigmented and nonpigmented ciliary epithelia. Type VII collagen is distributed particularly at the strained parts of the accommodation system. Type VII collagen was associated with various basement membranes and with ciliary zonules. Anchoring fibrils were not visualized. Conclusions Type VII collagen distribution at strained areas suggests a supporting role in tissue integrity.