Tip of the Month
Publishing date: December 2008
The Science behind the Tip
Pseudoexfoliation or exfoliation syndrome (PEX) is the most common identifiable condition associated with glaucoma. Individuals can have PEX and not develop glaucoma, but they are at high risk. In a recent population-based study with long-term follow-up, 16% of PEX patients required treatment upon presentation and of the remaining patients, 44% received therapy over the next 15 years(1). Further, the prognosis of pseudoexfoliaton glaucoma is worse than that of primary open-angle glaucoma. In EMGT, progression risk was doubled among patients with PEX(2).
Screening of relatives of PEX patients is useful because several clinical studies have indicated that PEX runs in families(3). Research into the genetic basis of PEX has recently led to the discovery that variants in the LOXL(1) gene on chromosome 15 are strongly associated with pseudoexfoliation glaucoma(4,5). The LOXL(1) protein encoded by the gene is involved in the formation of elastin fibers and appears to play a role in the accumulation of the deposits that causes PEX.
Contributor: Ann Hoste, Antwerp
Co-editors: John Thygesen and Ann Hoste
Peer reviewers: Roger Hitchings and Anders Heijl
1. Jeng SM, Karger RA, Hodge DO, et al. The risk of glaucoma in pseudoexfoliation syndrome. J Glaucoma. 2007;16:117-21.
2. Leske MC, Heijl A, Hussein M, et al. Factors for glaucoma progression and the effect of treatment: the early manifest glaucoma trial. Arch Ophthalmol. 2003;121:48-56.
3. Allingham RR, Loftsdottir M, Gottfredsdottir MS, et al. Pseudoexfoliation syndrome in Icelandic families. Br J Ophthalmol. 2001;85:702-7.
4. Thorleifsson G, Magnusson KP, Sulem P, et al. Common sequence variants in the LOXL1 gene confer susceptibility to exfoliation glaucoma. Science. 2007;317:1397-400.
5. Fan BJ, Pasquale L, Grosskreutz CL, et al. DNA sequence variants in the LOXL1 gene are associated with pseudoexfoliation glaucoma in a U.S. clinic-based population with broad ethnic diversity. BMC Med Genet.
2008 Feb 6;9:5.
The full text can be found at http://www.biomedcentral.com/1471-2350/9/5
Tip Reviewer: Roger Hitchings
Tip Editors: Ann Hoste, John Salmon and John Thygesen