Predisposing factors for chronic angle-closure glaucoma

https://doi.org/10.1016/S1350-9462(98)00007-XGet rights and content

Abstract

Chronic angle-closure glaucoma is the commonest form of glaucoma in Sino–Mongaloid populations. It is an anatomical disorder of the anterior segment of the eye characterised by permanent closure of part of the filtration angle as a result of iris apposition to the trabecular meshwork. Two pathways lead to this condition: recurrent pupillary block and “creeping” angle closure. East or Southeast Asian ethnic background is an important risk factor for the development of chronic angle-closure glaucoma. Other demographical risk factors include ageing, female gender and a familial tendency. Eyes with chronic angle-closure glaucoma have different anterior segment anatomical relationships when compared to normals. Those eyes at risk tend to be hypermetropic with a shallow anterior chamber, a relatively anteriorly positioned lens and a short axial length. The role of the ciliary body anatomy and ciliary processes in the pathogenesis of this condition requires further investigation.

Introduction

Chronic angle-closure glaucoma is an anatomical disorder of the anterior segment of the eye characterised by permanent closure of part of the filtration angle as a result of iris apposition to the trabecular meshwork. The subsequent rise in intraocular pressure can cause optic nerve damage that is indistinguishable from that found in chronic open-angle glaucoma. It is one of the clinical forms of primary angle-closure glaucoma.

Chronic open-angle glaucoma is the commonest form of glaucoma in North America (Tielsch et al., 1991; Javitt & Sommer, 1991) Europe (Hollows and Graham, 1966) and Africa (Bartholomew, 1976) and acute angle-closure glaucoma is the commonest presenting feature of primary angle-closure glaucoma in Europeans (Leighton et al., 1971). It is therefore not surprising that researchers have concentrated on these forms of glaucoma. However, recent prevalence studies undertaken in East Asia (Congdon et al., 1996; Foster et al., 1996). have shown that chronic angle-closure glaucoma is more prevalent than open-angle glaucoma in Sino–Mongaloid populations, which suggests that chronic angle-closure glaucoma could be the most prevalent form of glaucoma in world-wide terms. It is clearly the most important cause of preventable blindness in elderly East and Southeast Asians (Lim, 1979; Congdon et al., 1992). The demographical and anatomical factors which play a role in the development of chronic angle-closure glaucoma will be considered in this review.

Section snippets

Nomenclature and definitions

The word “glaucoma” does not refer to a single disease entity but rather to a group of diseases that differ in their pathophysiology, clinical presentation and treatment. The most useful classification system was introduced by Barkan (1938) and divides the acquired glaucomas into open-angle forms and angle-closure forms.

When the intraocular pressure is raised in open-angle glaucoma it is because of increased resistance to aqueous outflow through the trabecular meshwork—Schlemm's

Ethnicity as a risk factor

Ethnicity was not recognised as a major risk factor for chronic angle-closure glaucoma by Ida Mann (1966) in her book “Culture, Race, Climate and Eye Disease”. Although it was suspected in the 1980s that chronic angle-closure glaucoma might be more common in Asians than in Europeans, it was only in 1992 that a comprehensive review of the literature (Congdon et al., 1992), confirmed that ethnic background plays a major demographical role in this condition.

This conclusion was based mainly on the

Age

The prevalence of chronic angle-closure glaucoma increases with age and the diagnosis is made in most patients in the seventh decade of life (Salmon, 1993b). In Southeast and East Asia however, patients often present with advanced chronic angle-closure glaucoma at an early age (Loh, 1968; Lim, 1979). The anterior chamber depth decreases with age; a trend that has been clearly demonstrated in prevalence studies on individuals of mixed Southeast Asian ethnic background (Salmon et al., 1993). When

Anatomical risk factors

The measurement of eyes with primary angle-closure glaucoma and the relationship of one intraocular structure to another was comprehensively documented in Europeans more than 25 years ago (Lowe, 1969a, Lowe, 1969b, Lowe, 1970). In comparison, ocular biometry has only recently been reported in individuals of Southeast Asian and Sino–Mongoloid ethnic background with primary angle-closure glaucoma (Salmon et al., 1994; Congdon et al., 1996). These studies have established that eyes with primary

Future directions of research

Prevalence studies need to be undertaken in Southeast Asia, the Indian subcontinent and the Middle East to determine whether the prevalence of chronic angle-closure glaucoma is the same as that found in Mongolia and China. Although it has been shown (Wilensky et al., 1993) that there is no parameter that is sensitive enough to predict which eyes with a shallow anterior chamber and an occludable angle will later develop primary angle-closure glaucoma, the sensitivity and specificity of the

Conclusion

Chronic angle-closure glaucoma is a common cause of blindness in Asia. Many East and Southeast Asians live in Europe and North America and so an understanding of this form of glaucoma is important for ophthalmologists throughout the world. This review has considered the demographical and anatomical risk factors underlying chronic angle-closure glaucoma and has highlighted the need for further research into the disease so that the necessary steps can be taken to prevent visual loss in these

References (60)

  • P.H. Alsbirk

    Primary angle-closure glaucoma; oculometry epidemiology and genetics in a high risk population

    Acta. Ophthalmol. Suppl.

    (1976)
  • Alsbirk, P. H. (1984) Prevention and control of visual impairment and blindness (with special reference to glaucoma) in...
  • S.M. Arkell et al.

    The prevalence of glaucoma among Eskimos of Northwest Alaska

    Arch. Ophthalmol.

    (1987)
  • R.S. Bartholomew

    Glaucoma in a South African black population. A population study on the Pondo tribe of South Africa

    S. Afr. Arch. Ophthalmol.

    (1976)
  • S.K. Bhargova et al.

    Early angle-closure glaucoma. Distribution of iridotrabecular contact and response to pilocarpine

    Arch. Ophthalmol.

    (1973)
  • O. Barkan

    Glaucoma: classification, causes and surgical control

    Am. J. Ophthalmol.

    (1938)
  • L.L. Cavalli-Sforza

    Genes, peoples and languages

    Sci Am

    (1991)
  • P.A. Chandler

    Narrow-angle glaucoma

    Arch. Ophthalmol.

    (1952)
  • V. Clemmesen et al.

    Primary angle closure glaucoma in Greenland

    Acta. Ophthalmol.

    (1971)
  • V. Clemmesen et al.

    Lens thickness and angle-closure glaucoma

    Acta. Ophthalmol. (Copenh.)

    (1976)
  • N.G. Congdon et al.

    Screening techniques for angle-closure glaucoma in rural Taiwan

    Acta. Ophthalmol. Scand.

    (1996)
  • J.E. Cox

    Angle-closure glaucoma among the Alaskan Eskimos

    Glaucoma

    (1984)
  • S.M. Drance

    Angle-closure glaucoma among Canadian Eskimos

    Can. J. Ophthalmol.

    (1973)
  • P.J. Foster et al.

    Glaucoma in Mongolia: a population-based survey in H±“vsg”l province, Northern Mongolia

    Arch. Ophthalmol.

    (1996)
  • W.S. Foulds et al.

    Some observations on chronic closed-angle glaucoma

    Br. J. Ophthalmol.

    (1957)
  • P.W. Gao et al.

    A statistical comparison of glaucoma in the Third Affiliated Hospital of China Medical College and Kyushu University (Japan)

    Acta. Soc. Ophthalmol. Jpn

    (1989)
  • C.A. Genio et al.

    Glaucoma profile at the Phillipines General Hospital

    Phillipines J. Ophthalmol.

    (1983)
  • Gorin, G. (1960) Shortening of the angle of the anterior chamber in angle-closure glaucoma. Am. J. Ophthalmol....
  • H. Hikishima et al.

    A clinical analysis of primary angle-closure glaucoma patients

    Folia Ophthalmol. Jpn

    (1986)
  • F.C. Hollows et al.

    Intraocular pressure, glaucoma and glaucoma suspects in a defined population

    Br. J. Ophthalmol.

    (1966)
  • Cited by (79)

    • Fifteen-Year Incidence Rate of Primary Angle Closure Disease in the Andhra Pradesh Eye Disease Study

      2021, American Journal of Ophthalmology
      Citation Excerpt :

      We found an inverse relationship between the rate of cataract surgery and the incidence of PACD (Figure 2), as in CEDIS.11 Female sex is a known risk factor for PACD,25 and women have shorter axial length and shallower anterior chamber depth than men.26-28 Women were 2.7 times more likely to have PACD in our study.

    • Primary Angle Closure

      2016, Ophthalmology
    View all citing articles on Scopus
    View full text