Influence of Anterior Segment Trauma on Endogenous Hyaluronan in the Rabbit Cornea and Aqueous

Endogenous hyaluronan in the normal and traumatized rabbit iris

“…We have in this study confirmed the previous observation that the hyaluronan content of the aqueous humour increases rapidly in response to a trauma, and that this response peaks after about 2 days (Molander et al 1993b). However, the levels reached in the present paper are lower, 2.0∫0.2 mg/ml, whereas much higher levels can be reached in experimental cataract surgery (6.2∫0.43 mg/ ml).…”

“…The production is likely to be high also in the anterior segment, because the turnover in the anterior chamber is high, about 3 mg/day, corresponding to a half-life of between 60-100 minutes (Laurent 1982). In our study, the aqueous humor hyaluronan reached its peak about 12 hours before the peak is reached after cataract surgery (Molander et al 1993b). This suggests that the cataract extraction trauma gives a more persistent irritation than plain iridectomy.…”

“…We presume that a complete cataract operation results in more trauma than a simple iridectomy. Non-perforating radial keratotomy is probably even less traumatic, and did not cause any significant changes in aqueous hyaluronan (Molander et al 1993c).…”

“…However, the specific tissues and cells responsible for hyaluronan synthesis in the anterior segment are still unknown. Varying amounts of hyaluronan have been found in the ciliary body, sclera, conjunctiva, corneal endothelium, zonules and iris (Lü tjen-Drecoll et al 1990, Molander et al 1993a, 1993b, 1993c.…”

“…after extracapsular lens extraction (Molander et al 1993a) and radial keratotomy (Molander et al 1993c), after excimer laser treatment and in alkali lesions . The biological reasons for the changes remain obscure.…”