ABSTRACT
>L)Xyq Purpose: To quantify the prevalence of cataract, the outcomes
l{vi{9n) of cataract surgery and the factors related to
}4\>q$8' unoperated cataract in Australia.
6SW:'u|90 Methods: Participants were recruited from the Visual
ZJ u\ Impairment Project: a cluster, stratified sample of more than
,!PNfJA2 5000 Victorians aged 40 years and over. At examination
F71.%p7C8" sites interviews, clinical examinations and lens photography
2~~Q NWN were performed. Cataract was defined in participants who
/tx_I(6F?| had: had previous cataract surgery, cortical cataract greater
^BSMlKyB than 4/16, nuclear greater than Wilmer standard 2, or
EVrOu"" posterior subcapsular greater than 1 mm2.
B
u*ge~ Results: The participant group comprised 3271 Melbourne
8x[q[ residents, 403 Melbourne nursing home residents and 1473
^=FtF9v rural residents.The weighted rate of any cataract in Victoria
E.4`aJ@>d was 21.5%. The overall weighted rate of prior cataract
XEY((VL0 surgery was 3.79%. Two hundred and forty-nine eyes had
X{<j%PdC had prior cataract surgery. Of these 249 procedures, 49
@y{Whun~ (20%) were aphakic, 6 (2.4%) had anterior chamber
q/<.^X intraocular lenses and 194 (78%) had posterior chamber
Of SYOL7o intraocular lenses.Two hundred and eleven of these operated
pX*Oc6.0mu eyes (85%) had best-corrected visual acuity of 6/12 or
>Ix)jSNLgo better, the legal requirement for a driver’s license.Twentyseven
7-Fh!=\f/ (11%) had visual acuity of less than 6/18 (moderate
+mYD
DlvI vision impairment). Complications of cataract surgery
hA/K>Z caused reduced vision in four of the 27 eyes (15%), or 1.9%
e(,sFhR of operated eyes. Three of these four eyes had undergone
J$v0 intracapsular cataract extraction and the fourth eye had an
ie=tM'fb opaque posterior capsule. No one had bilateral vision
a$l/N{<. impairment as a result of cataract surgery. Surprisingly, no
.COY%fz particular demographic factors (such as age, gender, rural
4JT9EKo residence, occupation, employment status, health insurance
-_4U+Cfmtl status, ethnicity) were related to the presence of unoperated
^kzw/.I{ cataract.
=;i@,{
~ Conclusions: Although the overall prevalence of cataract is
3z!\Z[ quite high, no particular subgroup is systematically underserviced
*U)!9DvA in terms of cataract surgery. Overall, the results of
K#}DXq cataract surgery are very good, with the majority of eyes
OGzth$7A achieving driving vision following cataract extraction.
&zynfj#o Key words: cataract extraction, health planning, health
^$4d' services accessibility, prevalence
JD^(L~ n] INTRODUCTION
)K4 |-<i Cataract is the leading cause of blindness worldwide and, in
?A3pXa Australia, cataract extractions account for the majority of all
2n2{Oy>L ophthalmic procedures.1 Over the period 1985–94, the rate
^EPM~cEY\ of cataract surgery in Australia was twice as high as would be
#e((F,
1z expected from the growth in the elderly population.1
tq8B)<(] Although there have been a number of studies reporting
[u[F6Wst the prevalence of cataract in various populations,2–6 there is
+FP*RNM little information about determinants of cataract surgery in
k`F$aQV9` the population. A previous survey of Australian ophthalmologists
8&7LF showed that patient concern and lifestyle, rather
*Sm$FMWQ than visual acuity itself, are the primary factors for referral
]2T =%(* for cataract surgery.7 This supports prior research which has
TartV3;` shown that visual acuity is not a strong predictor of need for
U+3,(O cataract surgery.8,9 Elsewhere, socioeconomic status has
+ G#qS1 been shown to be related to cataract surgery rates.10
0Y,_
DU To appropriately plan health care services, information is
j{?,nJdQ needed about the prevalence of age-related cataract in the
{0+gPTp community as well as the factors associated with cataract
oe}nrkmb surgery. The purpose of this study is to quantify the prevalence
(%ra~s? of any cataract in Australia, to describe the factors
Jtnuo]{R related to unoperated cataract in the community and to
lpQsmd# describe the visual outcomes of cataract surgery.
>:%i,K*AM METHODS
6UXa
5t
Study population
rj& Details about the study methodology for the Visual
9->E$W Impairment Project have been published previously.11
v|C)Q %v Briefly, cluster sampling within three strata was employed to
!2s<
v recruit subjects aged 40 years and over to participate.
OM*N) * Within the Melbourne Statistical Division, nine pairs of
PsU.dv[ census collector districts were randomly selected. Fourteen
3
[: x#r nursing homes within a 5 km radius of these nine test sites
{|c
<8 were randomly chosen to recruit nursing home residents.
T%A45BE
V Clinical and Experimental Ophthalmology (2000) 28, 77–82
B.vg2N Original Article
O'{UAb+- Operated and unoperated cataract in Australia
Y[k%<f Catherine A McCarty PhD, MPH, Mukesh B Nanjan PhD, Hugh R Taylor MD
-(V]knIF Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
fEf",{I n Correspondence: Dr Cathy McCarty MPH, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne,
p8o
~ Victoria 3002, Australia. Email:
cathy@cera.unimelb.edu.au %B5.zs]Of 78 McCarty et al.
%p6"Sg* Finally, four pairs of census collector districts in four rural
,rVm81-2 Victorian communities were randomly selected to recruit rural
-bJht residents. A household census was conducted to identify
H6X]D"Y, eligible residents aged 40 years and over who had been a
/_
}xTP"9 resident at that address for at least 6 months. At the time of
_\waA^ F the household census, basic information about age, sex,
vY0C(jK country of birth, language spoken at home, education, use of
Mk9' corrective spectacles and use of eye care services was collected.
9r=@S Eligible residents were then invited to attend a local
_Bm/v^( examination site for a more detailed interview and examination.
6<jh0=$ The study protocol was approved by the Royal Victorian
5RCQ<1 Eye and Ear Hospital Human Research Ethics Committee.
3on]#/"1b Assessment of cataract
F!OVx< A standardized ophthalmic examination was performed after
[u\E*8 pupil dilatation with one drop of 10% phenylephrine
tn!z^W hydrochloride. Lens opacities were graded clinically at the
&.D3f" time of the examination and subsequently from photos using
F`KA^ZI the Wilmer cataract photo-grading system.12 Cortical and
(]7&][ posterior subcapsular (PSC) opacities were assessed on
k?ubr)
[) retroillumination and measured as the proportion (in 1/16)
I:l<t* of pupil circumference occupied by opacity. For this analysis,
yx?Z&9z <