Newsletter Tip of the Month |
Publishing date: February 2013
The Science behind the Tip
Primary angle closure glaucoma is rare in younger white adults, with an estimated age specific prevalence of 0.02% for those 40-49 years. It is so uncommon in young, white men that they should be thoroughly investigated to identify a cause.
Posterior uveitis and idiosyncratic drug reactions should be excluded. A comprehensive ocular examination is mandatory, and B mode ultrasound and ultrasound biomicroscopy imaging may be useful in identifying mass effects. Asymmetry in anterior chamber depth of more than 0.5 mm indicates that there is probably a secondary, retro-lenticular mechanism. Bilaterally short eyes (typically >1 SD below population mean: i.e. < 22.5 mm for men, < 22.00 for women) suggest "primary" mechanisms, with younger onset triggered by environmental exposures such as antidepressants or adrenergic decongestants.
Angle-closure is linked to Best maculopathy, and Fibrillin-1 mutations in the Marfan/Weill-Marchesani spectrum. A family history of joint laxity and knee/hip replacement surgery is common, and points to collagen abnormalities. Abnormal collagen confers an increased risk in surgery.
Contributors: Alexander Day and Paul Foster, London
References
1. Day AC, Baio G, Gazzard G, et al. The prevalence of primary angle closure glaucoma in European derived populations: a systematic review. Br J Ophthalmol. 2012;96:1162-7. Published Online First: 31 May 2012. doi:10.1136/bjophthalmol-2011-301189.
2. Chang BM, Liebmann JM, Ritch R. Angle closure in younger patients. Trans Am Ophthalmol Soc. 2002;100:201-12; discussion 212-4.
Tip Reviewer: Roger Hitchings
Tip Editors: Ann Hoste, John Salmon and John Thygesen
