Can we prevent angle-closure glaucoma?

Abstract

Purpose Glaucoma is the second cause, after cataract, of world blindness. Approximately half is thought to be primary angle-closure glaucoma (ACG). This review asks whether ACG can be prevented on a population basis. Methods and populations Review of published information from the Inuit of Greenland, Canada and Alaska, and descriptions of recent studies in Asian populations in Mongolia, China and SouthEast Asia. Results The Greenland Inuit have the shallowest anterior chamber depths (ACDs) so far recorded. The proportion of blindness due to ACG was reduced from 64% to 9% over 37 years by systematic optical measurement of central ACD and the van Herick test in the older Inuit, followed by gonioscopy and prophylactic iridectomy or laser iridotomy when indicated. In Mongolia, ultrasound measurement of central ACD had good sensitivity and specificity as a screening test. A randomized controlled trial of screening and prophylactic laser is being completed. In China and South-East Asia, the mechanism of angle closure appears to be more varied and complex and its detection may require more elaborate imaging. Conclusions The mechanism of angle closure and potential for prevention by screening are likely to have to be determined specifically for each population at risk.

Ethnic differences in primary angle-closure glaucoma

“…Despite this, the proportion of blindness due to PACG in Greenland Inuit has been reduced from 64% to 9% over 37 years by biometric screening in older people, followed by gonioscopy and prophylactic iridotomy when indicated [28].…”

Definition, Classification, and Pathophysiology of Canine Glaucoma

“…23,67 In ethnic groups predisposed to PACG the anterior chamber is shallower, the lens larger, and the filtration angle width is decreased. 68 The apposition of the peripheral iris with the peripheral cornea or formation of peripheral anterior synechiae can cause the obstruction of the TM, which in primates is located anterior to the iris base. 23 Miller and colleagues 69 hypothesized that similar mechanisms involving the position of the iris might be responsible for some forms of PACG in dogs.…”

Histological Presence of <i>Helicobacter pylori</i> Bacteria in the Trabeculum and Iris of Patients with Primary Open-Angle Glaucoma

“…After cataract it is the second most frequent cause of world blindness and therefore is of major public health importance [1][2][3] . A theoretical relationship exists between glaucoma and Helicobacter pylori infection: (1) both are diseases of older adults in the developed world [4] ; (2) chronic H. pylori infection may produce systemic disorders involving vascular tone resulting from the release of vasoactive and proinflammatory substances [4] , and (3) H. pylori infection is associated with arteriosclerosis-induced increased platelet activation and aggregation [4] . It is thus important to investigate the role of H. pylori infection in glaucoma initiation, progression or susceptibility by documenting its qualitative and quantitative presence in this disease.…”