Page 343 - Biomedical Engineering and Design Handbook Volume 1, Fundamentals

320 BIOMATERIALS

TABLE 13.1 Data for Commercial HA Solutions Used in Opthalmic Surgery
Molecular weight,
Product Concentration, % g/mol × 10 6 Viscosity, mPa·s
Microvisc Plus 1.4 7.9 n.i.*
Morcher Oil Plus 1.4 7.9 1 × 10 6
Morcher Oil 1 6.1 1 × 10 6
Microvisc 1 5 n.i.
Healon GV 1.4 5 2 × 10 6
Viscorneal Plus 1.4 5 500,000
Allervisc Plus 1.4 5 500,000
Viscorneal 1 5 200,000
Allervisc 1 5 200,000
Healon5 2.3 4 7 × 10 6
HSO Plus 1.4 4 4.8 × 10 6
HSO 1 4 1 × 10 6
Healon 1 4 200,000
Dispasan Plus 1.5 >3 2.5 × 10 6
Visko Plus 1.4 3 500,000
BioLon 1 3 115,000
Dispasan 1 >2 35,000
Visko 1 2 300,000
Hya-Ophtal 2 2 n.i.
Amvisc Plus 1.6 1.5 60,000
IALUM 1.2 1.2 10,000
IALUM-F 1.8 1.2 22,000
Provisc 1 >1.1 50,000
Rayvisc 3 0.8 50,000
AMO Vitrax 3 0.5 40,000
Viscoat 3 >0.5 ca. 40,000
* n.i. = not investigated.
Source: Reproduced from H. B. Dick and O. Schwenn, Viscoelastics in Ophthalmic Surgery.
Berlin: Springer-Verlag, 2000, p. 34.
Hyaluronic acid (HA) is a very lubricious, high-molecular-weight, water-soluble polymer found in
connective tissue and the sinovial fluid that cushions the joints. HA is also found in the vitreous and
aqueous humors of the eye. Solutions are injected in the eye during intraocular lens surgery to
protect the cornea and the iris from damage during surgery. Table 13.1 shows data on HA concen-
tration, molecular weight, and viscosity for some commercially available HA solutions. HA is
currently being investigated to prevent postoperative adhesions. Since HA has many functional groups
(OH, carboxylate, acetamido), it can be cross-linked by a variety of reagents. Therefore, HA may
have applications as a hydrogel drug delivery matrix. 17
Dextran. Degradation: biodegradable.

CH 2
O
H H
H
OH H
HO O CH 2
O
H OH H H
H
OH H
HO O
Dextran H OH
n