Peripheral rheumatoid ulceration and evidence for conjunctival collagenase production.

Two patients with rheumatoid arthritis and peripheral corneal ulcerations were successfully treated by conjunctival resection. The tissues removed were assayed by a variation of the radial diffusion method for tissue collagenases. We used an agarose matrix containing lathyritic rat skin collagen. Wells 3 mm deep were punched in the agarose-collagen and surgical specimens were placed in the wells. Spaces remaining in the wells were filled with balanced salt solution. The assay dishes were incubated for four days at 32 degrees C near 100% humidity. Under these conditions release of collagenase was detected by the clearing of diffuse zones in the gel surrounding the well. Conjunctiva proximal to the ulcer produced definite zones of lysis, whereas control specimens taken remote to the ulceration produced no lysis. This direct evidence for collagenase involvement offers an exploration for the beneficial effects of conjunctival resection.