Glycosaminoglycans as Clinical Applications

Topical heparin eyedrops were effective for long-term reduction of fibrotic posterior capsule opacification after extracapsular cataract extraction with intraocular lens implantation (93). Implantation of a heparin drug delivery system into the posterior chamber of experimental animals maintained a significantly higher heparin level in the aqueous humor for a long period of time, suggesting the potential for effective prevention of posterior capsular opacification after phacoemulsification of the lens with no toxic or side effects (94). 

Although patients with pseudoexfoliation syndrome generally showed higher blood-aqueous barrier permeability than the control subjects, the patients implanted with heparin surface-modified intraocular lenses showed decreased permeability compared with the control subjects after surgery (95). Correspondingly, eyes with exfoliation syndrome exhibited a reduced incidence of posterior capsule opacification after implantation of heparin surface-modified intraocular lenses (96). 

Heparin may prevent postoperative fibrin formation in eyes undergoing surgery for complications of proliferative diabetic retinopathy, proliferative vitreoretino-pathy, and glaucoma filtration surgery. 

The inhibitory effect of infusion of low-molecular-weight heparin sodium during lensectomy, vitrectomy, and retinotomy on intraocular fibrin formation was demonstrated in a rabbit model (97). Similarly, the preventative effect of heparin on postoperative intraocular fibrin clot formation was evaluated in the rabbit after vitrectomy and cyclocryotherapy. A single anterior chamber injection of heparin supplemented in the infusion solution or a single intravenous injection each resulted in a statistically significant reduction in postoperative intraocular fibrin formation (98). No ocular bleeding complications developed postoperatively. 

A single collagen shield soaked in heparin achieved anterior chamber anticoagulant levels and resulted in fibrin inhibition during a 6-h study period, while a subconjunctival heparin injection did not alter the baseline aqueous anticoagulant activity (99). No complications related to collagen shield heparin delivery were encountered. 

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