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This could lead to inadvertent lens damage during iridectomy, vitreous loss, or late incarceration of vitreous into the internal ostium. Hyphema from the surgical iridectomy could be the result of undetected iris fine neovascularization, which occurs in XFG. After trabeculectomy, there is an increased possibility of cataract progression in patients with XFG. The more advanced the disease and the longer the duration of it the higher the likelihood for complications to occur.

Trabeculotomy, performed with the rationale that it may bypass mechanical blockage of the trabecular meshwork, has been reported successful (Gillies, 1977; Tanihara et al., 1993; Honjo et al., 1998). Along similar lines of reasoning, Jacobi et al. (1998) described a procedure termed trabecular aspiration, designed to improve outflow facility.

Deep sclerectomy and similar procedures including a deroofing of Schlemm’s canal are becoming popular choices in some centers owing to the reduced risk profile of nonpenetrating surgery. Patients with XFG had significantly better success than those with POAG following deep sclerectomy with either an absorbable collagen implant or a nonabsorbable hydrophylic acrylic implant (Drolsum, 2003, 2006). Another study showed equal effectiveness (Rekonen et al., 2006). Phacoemulsification combined with penetrating and nonpenetrating procedures does not seem to adversely influence success rate.

Future treatment of exfoliation syndrome and exfoliative glaucoma

For most of the twentieth century, glaucoma was equated with elevated IOP, and all therapy has been guided at lowering IOP. Directed therapy simply means devising specific treatments for specific diseases. There was little incentive to attempt to distinguish between various open-angle glaucomas if the treatments were essentially the same. However, this view also prevented the application of directed therapy in those instances in which such was available and applicable.

Aqueous outflow

Miotics, which improve trabecular outflow, as mentioned above, have nearly passed from the armamentarium for treatment of glaucoma. Drugs which affect the integrity of the cytoskeleton of the trabecular meshwork, may be a boon to the treatment of XFS and XFG, although they have not yet been examined for this purpose. Over 30 years ago, Kaufman and Ba´ra´ny (1977) showed that intracameral cytochalasin B caused an increase in outflow facility in the eyes of cynomolgus monkeys. Bill et al. (1980) described cell separation in the trabecular meshwork after intracameral injection of sodium-EDTA. There was also distention of the juxtacanalicular meshwork, washout of extracellular material, and disintegration of the denuded trabecular cores. Use of these drugs never came to fruition in patients because of potential toxicity, particularly to the cornea, but it can be seen that a washout of extracellular material from the trabecular meshwork might be a breakthrough approach to the treatment of XFS if the blockage to the trabecular meshwork could be removed and have a longlasting effect. The serine–threonine protein kinase inhibitor H-7 was shown to have a similar effect on the trabecular meshwork by a different mechanism (Tian et al., 1999) probably by inhibiting cell contractility, cytoskeletal support, and cell–cell adhesions in the trabecular meshwork (Tian et al., 1998).

More recently, latrunculin B administered topically has been shown to increase aqueous outflow facility by a similar mechanism (Peterson et al., 2000) without having any adverse effect on the retinal vascular permeability or electrophysiology (Kiland et al., 2006) or affecting the cornea (Okka et al., 2004; Sabanay et al., 2006). Latrunculins bind to the free actin in the cell, preventing it from polymerizing into microfilaments. The existing actin cytoskeleton gradually degenerates, leading to a large increase in outflow facility (Ethier et al., 2006). Depending on its effect on the XFM and pigment blocked in the intertrabecular spaces, an effect as yet undetermined, latrunculin may turn out to be a drop which might be given much less than once a day, perhaps even once a week or once