Abstract
Purpose:
Vitreous plays important roles in the pathogenesis of vitreo-retinal diseases including proliferative diabetic retinopathy, proliferative vitreoretinopathy and others. Hyaluronan (HA) is contained in vitreous and this affects the pathogenesis of those diseases including fibrovascular membrane formation.To remove the formed vitreous gel is useful to treat those proliferative diseases by vitrectomy. Hyaluronidase is one of the vitreolytic substances to hydrolize HA, and may be applied to the chemical vitrectomy. To clarify the clinical significance of the degradation of HA, it is necessary to clarify the correlation between the vitreous status and HA. In this research project, the degradation process of HA by hyaluronidase was investigate in the in vitro system.
Methods:
Fifty porcine eyes of 2 year old of age were obtained from a slaughterhouse. In all the experiments, we treated right eyes, and used left eyes as controls. The vitreous was obtained from eye balls using the 25-gauge vitrectomy system. Whole vitreous body was dissected carefully from corneal open sky incision with compression the eyeball. To investigate the degradation of HA by the human recombinant hyaluronidase, we measured the HA concentration in the vitreous specimen (200μl) treated with 1.5 Unit of Hilenex® (human recombinant hyaluronidase) by ELISA. To observe the effect of the human recombinant hyaluronidase on the vitreous structure, we measured the volume of the whole porcine vitreous treated with 15 Unit of Hilenex®.
Results:
The mean HA concentration of the vitreous gel after treatment by the human recombinant hyaluronidase was lower than control (5.74 vs 142.5 ng/ml, respectively, Mann-Whitney U test p<0.001). The mean volume of the whole vitreous after treatment with hyaluronidase was lower the control (1.79 vs 2.45 gram, respectively, Mann-Whitney U test p<0.001). Human recombinant hyaluronidase could significantly degradate the HA in the vitreous specimens and decrease the volume of the whole vitreous.
Conclusions:
Human recombinant hyaluronidase could destroy the vitreous gel structure by the degradation of HA in the porcine vitreous. Hyaluronidase and/or similar agents can be used as an adjuvant for the chemical vitrectomy.
Keywords: 763 vitreous •
764 vitreous substitutes •
503 drug toxicity/drug effects