Optical Properties of Viscoelastic Substances

All viscoelastic substances show a slightly higher refractive index than water. 

Amvisc PluSi Heaion GV, Amviw, Dispasan, Healon 1.3382 to 1.3372 

Specific safety requirements are placed on viscoelastic substances employed in-traocularly. They must be sterile, pure and free of particles, as well as non-immu-nogenic, non-toxic and non-inflammatory. They must be biologically inert and show a balanced electrolyte content. Osmolality and colloid osmotic pressure as well as pH (see below) must correspond to corneal and aqueous humor values (pH = 7.38). They should be water-soluble and clear for implementation in the anterior chamber. Viscoelastic substances should be easily applied and removed, but, nonetheless, biologically transportable or biodegradable in the event of residues. They should be long-lasting and preferably storable at room temperature. 

Content, molecular weight, pH-value, buffer substance and osmolality should all be included by the manufacturer in the product insert. 

An overview of company information in terms of current commercially-marketed viscoelastic properties is presented in the Appendix Table. It is significant to take into account molecular weight, concentration and chemical composition when comparing these substances, especially with those manufactured by different companies. 

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