[Study on safety of sodium hyaluronate (SL-1010) by injection in the anterior chamber].

We investigated effects of a newly developed sodium hyaluronate (SL-1010) on the anterior segment of the eye. The tested sodium hyaluronate was biosynthesized using Streptococcus zoo-epidemicus. Under an operating microscope, we replaced the aqueous humor of Macaca fascicularis (n = 3) with 150 microliters of 1% sodium hyaluronate solution without loss of the anterior chamber. The opposite eye was treated as a control and its aqueous was replaced with the same volume of the vehicle, isotonic phosphate buffer solution. We performed follow-up clinical examination with slit-lamp microscopy, pachymetry, pneumotonometery, and specular microscopy. On the 7th day, we performed histological study by light microscopy, transmission and scanning electron microscopy. Although the sodium hyaluronate group showed a significant increase of intraocular pressure at 9 hours after the treatment over the control, there were no significant differences in clinical findings between the sodium hyaluronate and the control groups. Histological studies demonstrated nothing particular except for slight swelling of mitochondria of corneal endothelial cells in both groups. It was concluded that the newly developed sodium hyaluronate is a biologically inactive and safe biomaterial.