NHMRC Glaucoma Guidelines - ANZGIG

NHMRC GUIDELINES FOR THE SCREENING, PROGNOSIS, DIAGNOSIS, MANAGEMENT AND PREVENTION OF GLAUCOMA
Chapter 6 – Identifying those at risk of developing glaucoma
The Australian Bureau of Statistics (ABS) (2004) “National Aboriginal and Torres Strait Island Health
Survey 2004/05” provided data on long term eyesight problems. Eyesight problems were the most
commonly reported long term health condition amongst Aboriginal and Torres Strait Islander
peoples. However, glaucoma was not a condition specifically reported.
Several large surveys of vision loss in Aboriginal and Torres Strait Islander populations have been
conducted. Long term study of vision loss in people living in from remote Western Australia, including
annual surveys over 13 years up until 2007 - examined a total of 920 individuals. No cases of primary
open angle glaucoma were recorded (Clark, Morgan, Kain et al 2010). This population study included
a high proportion of people aged above 16 years with a mean age of 43. Cases of blindness and
visual impairment were identified. The most common causes of blindness and visual impairment were
cataract, diabetic retinopathy, refractive error and trauma. Whilst no cases of neovascular glaucoma
or traumatic induced glaucoma were found in this survey, anecdotal reports from major teaching
hospitals across Australia reveal that such cases occur.
Another large survey examining numerous groups of Aboriginal and Torres Strait Islander peoples
across Australia in both metropolitan and remote communities reported its findings in 2010 (Taylor,
Xie, Fox et al 2010). 1189 adults (median age 51) were examined with no cases of glaucoma found
in the sample population using optic disc photos and Matrix visual field evaluation.
The comparative incidence of glaucoma in 50 year olds is less in Aboriginal and Torres Strait
Islander populations generally, by 0.5%. Additionally, the proportion of blindness from glaucoma in
the Aboriginal and Torres Strait Islander populations surveyed to date appears to be much less than
the 14% commonly seen in non-indigenous population subsets (Yong, Morgan, Cooper et al 2006).
Indigenous Australians are less likely to develop primary open angle or angle closure glaucoma,
secondary forms of glaucoma, however, are occasionally seen in Aboriginal and Torres Strait
Islander people who have had trauma or neovascularisation due mainly to diabetes. These forms
of glaucoma are often difficult to treat and generally require referral to a major teaching hospital.
Frequency of visits to eye care providers
Increased time since last visit to an eye care provider was found to be associated with an elevated
risk of undiagnosed glaucoma by the Melbourne Visual Impairment Project (Weih et al 2001).
The likelihood of being diagnosed with probable or definite glaucoma rose from no risk (OR=1)
when attending an eye care provider in the last year to OR=9.8 (95% CI 3.0—31.3) when
attendance had not occurred for three or more years.
Smoking
The evidence supporting the association of smoking with the pathogenesis of POAG is controversial.
Although several studies have indicated that smoking is a risk factor for POAG development, other
studies have refuted the notion. In a systematic review and meta-analysis by Bonovas, Filioussi,
Tsantes et al (2004a), the results of six studies were analysed. This found that current smoking
results in a significant increase in the risk of POAG (OR=1.37, 95% CI 1.00–1.87), while past smoking
does not affect this risk (OR=1.03, 95% CI 0.77–1.38). Bonovas et al (2004a) concluded that the
meta-analysis findings support an association between current smoking and POAG.
Long-term steroid users
Corticosteroids are the main cause of drug-induced glaucoma (Adis International 2004). Steroids
administered by any route are associated with increases in IOP. Tripathi, Tripathi and Haggerty
(2003) report that 46-92% of subjects with OAG experience an increase in IOP after topical ocular
administration of corticosteroids lasting two-four weeks. Medication-induced glaucoma should be
54 National Health and Medical Research Council