ABSTRACT
-WT3)On Purpose: To quantify the prevalence of cataract, the outcomes
S]yvMj_? of cataract surgery and the factors related to
9)yG.9d1 unoperated cataract in Australia.
Y5jYmP< Methods: Participants were recruited from the Visual
LC'2q*:' Impairment Project: a cluster, stratified sample of more than
vO$ra5Z 5000 Victorians aged 40 years and over. At examination
t>U!Zal" sites interviews, clinical examinations and lens photography
qB JRS'6'9 were performed. Cataract was defined in participants who
vbn>
mg5 had: had previous cataract surgery, cortical cataract greater
,z66bnjO than 4/16, nuclear greater than Wilmer standard 2, or
z`'P>.x
posterior subcapsular greater than 1 mm2.
8t9aHla Results: The participant group comprised 3271 Melbourne
SLA#= K residents, 403 Melbourne nursing home residents and 1473
DM2Q1Dh3 rural residents.The weighted rate of any cataract in Victoria
uiK:*[ was 21.5%. The overall weighted rate of prior cataract
>0T3'/k<H surgery was 3.79%. Two hundred and forty-nine eyes had
l @A"U)
A( had prior cataract surgery. Of these 249 procedures, 49
f8!l7{2%q (20%) were aphakic, 6 (2.4%) had anterior chamber
lCE2SKj
intraocular lenses and 194 (78%) had posterior chamber
[s %\.y(q intraocular lenses.Two hundred and eleven of these operated
)[DpK=[N^p eyes (85%) had best-corrected visual acuity of 6/12 or
l\U*sro< better, the legal requirement for a driver’s license.Twentyseven
gX"T*d>y (11%) had visual acuity of less than 6/18 (moderate
t~~r-V": vision impairment). Complications of cataract surgery
.jum "va% caused reduced vision in four of the 27 eyes (15%), or 1.9%
Isp_U5M of operated eyes. Three of these four eyes had undergone
di<B ~:l58 intracapsular cataract extraction and the fourth eye had an
.
X
0t" opaque posterior capsule. No one had bilateral vision
A[RN-R, impairment as a result of cataract surgery. Surprisingly, no
n8?KSQy$ particular demographic factors (such as age, gender, rural
s'AQUUrb< residence, occupation, employment status, health insurance
KF4s
ee;; status, ethnicity) were related to the presence of unoperated
UNY@w=]< cataract.
Y(W{Jd+ Conclusions: Although the overall prevalence of cataract is
2q|_Dma quite high, no particular subgroup is systematically underserviced
YrKFa%k in terms of cataract surgery. Overall, the results of
Wb'*lT0= cataract surgery are very good, with the majority of eyes
}*ODM6 achieving driving vision following cataract extraction.
5#BF,-Jv Key words: cataract extraction, health planning, health
9$EHK services accessibility, prevalence
3v G
INTRODUCTION
1y(iE C Cataract is the leading cause of blindness worldwide and, in
NB3/A"}"02 Australia, cataract extractions account for the majority of all
mf#fA2[ ophthalmic procedures.1 Over the period 1985–94, the rate
MXh^dOWR of cataract surgery in Australia was twice as high as would be
@#1cx expected from the growth in the elderly population.1
AtuZF
Although there have been a number of studies reporting
frk7^5 the prevalence of cataract in various populations,2–6 there is
t0+t9w/fTP little information about determinants of cataract surgery in
`2sdZ/fO the population. A previous survey of Australian ophthalmologists
S q.9-h%5 showed that patient concern and lifestyle, rather
^CO#QnB @ than visual acuity itself, are the primary factors for referral
}t}38%1i for cataract surgery.7 This supports prior research which has
V5cb}xx shown that visual acuity is not a strong predictor of need for
%~ ;nlDw cataract surgery.8,9 Elsewhere, socioeconomic status has
h#v L5At been shown to be related to cataract surgery rates.10
KhLg*EL To appropriately plan health care services, information is
XlE$. needed about the prevalence of age-related cataract in the
jg7d7{{SB community as well as the factors associated with cataract
$Gr4sh!cE surgery. The purpose of this study is to quantify the prevalence
a"MTQFm' of any cataract in Australia, to describe the factors
"<7$2! related to unoperated cataract in the community and to
p, !1 3X describe the visual outcomes of cataract surgery.
axHxqhO7zp METHODS
#tCIuQ, Study population
f|;HS!$ Details about the study methodology for the Visual
-t;?P2 Impairment Project have been published previously.11
]v/t8` Briefly, cluster sampling within three strata was employed to
7)g;Wd+H recruit subjects aged 40 years and over to participate.
K'>P!R:El Within the Melbourne Statistical Division, nine pairs of
dOYlI`4 census collector districts were randomly selected. Fourteen
ddGkk@C
A nursing homes within a 5 km radius of these nine test sites
:-W$PIBe were randomly chosen to recruit nursing home residents.
F Bd+=bx,Z Clinical and Experimental Ophthalmology (2000) 28, 77–82
=M Q2sb Original Article
Y j,9V], Operated and unoperated cataract in Australia
BBaHMsr Catherine A McCarty PhD, MPH, Mukesh B Nanjan PhD, Hugh R Taylor MD
BA`kxL/x Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
"j*fVn n Correspondence: Dr Cathy McCarty MPH, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne,
Yb,G^+; Victoria 3002, Australia. Email:
cathy@cera.unimelb.edu.au UMnR=~. 78 McCarty et al.
1q;I7_{ 2 Finally, four pairs of census collector districts in four rural
Udb0&Y1^ Victorian communities were randomly selected to recruit rural
$Qx(aWE0 residents. A household census was conducted to identify
ee__3>H"/ eligible residents aged 40 years and over who had been a
^hGZVGSv resident at that address for at least 6 months. At the time of
;h*"E(Pp the household census, basic information about age, sex,
bCe[nmE2 country of birth, language spoken at home, education, use of
S1 R #] corrective spectacles and use of eye care services was collected.
,cl"1>lp Eligible residents were then invited to attend a local
zmrX%!CW examination site for a more detailed interview and examination.
{d{WMq$ The study protocol was approved by the Royal Victorian
d@`-!" Eye and Ear Hospital Human Research Ethics Committee.
'RN"yMv7l Assessment of cataract
3oNt]2w/' A standardized ophthalmic examination was performed after
<#J<QYF&2 pupil dilatation with one drop of 10% phenylephrine
MXu+I,y* hydrochloride. Lens opacities were graded clinically at the
0(.R?1*:Rf time of the examination and subsequently from photos using
-qr:c9\px the Wilmer cataract photo-grading system.12 Cortical and
' ]H#0. posterior subcapsular (PSC) opacities were assessed on
hyr5D9d retroillumination and measured as the proportion (in 1/16)
~"hAb2 of pupil circumference occupied by opacity. For this analysis,
YpbdScz
cortical cataract was defined as 4/16 or greater opacity,
Lq
H?3)
: PSC cataract was defined as opacity equal to or greater than
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