ABSTRACT
W5u5!L/ Purpose: To quantify the prevalence of cataract, the outcomes
b%lB&}uw} of cataract surgery and the factors related to
N[
=I unoperated cataract in Australia.
%<kfW&_>w Methods: Participants were recruited from the Visual
0se%|Z|8 Impairment Project: a cluster, stratified sample of more than
.
Z&5TK4I 5000 Victorians aged 40 years and over. At examination
%R$)bGT sites interviews, clinical examinations and lens photography
[6TI_U~ were performed. Cataract was defined in participants who
eP~3m had: had previous cataract surgery, cortical cataract greater
^x&x|ckR! than 4/16, nuclear greater than Wilmer standard 2, or
21OfTV-+3 posterior subcapsular greater than 1 mm2.
'`upSJ;e Results: The participant group comprised 3271 Melbourne
4&NB xe residents, 403 Melbourne nursing home residents and 1473
,P<I<QYu rural residents.The weighted rate of any cataract in Victoria
F,_cci`p was 21.5%. The overall weighted rate of prior cataract
|6d:k~p surgery was 3.79%. Two hundred and forty-nine eyes had
bpsyO>lx/ had prior cataract surgery. Of these 249 procedures, 49
k
Fl*Im (20%) were aphakic, 6 (2.4%) had anterior chamber
9-n]_AF`0 intraocular lenses and 194 (78%) had posterior chamber
<vl(a*4a intraocular lenses.Two hundred and eleven of these operated
~jw:4sG eyes (85%) had best-corrected visual acuity of 6/12 or
_,^f,WO~ better, the legal requirement for a driver’s license.Twentyseven
w8D8\`i!" (11%) had visual acuity of less than 6/18 (moderate
X:Y1g)|K vision impairment). Complications of cataract surgery
Vc'p+e|( caused reduced vision in four of the 27 eyes (15%), or 1.9%
xFUD9TM
of operated eyes. Three of these four eyes had undergone
yHM29fEZk intracapsular cataract extraction and the fourth eye had an
zpT{!V opaque posterior capsule. No one had bilateral vision
07^.Z[(pCt impairment as a result of cataract surgery. Surprisingly, no
QqL?? p-S> particular demographic factors (such as age, gender, rural
<=uO*s>% residence, occupation, employment status, health insurance
JK)|a@BtOT status, ethnicity) were related to the presence of unoperated
kk126?V]_ cataract.
AkjoD7.* Conclusions: Although the overall prevalence of cataract is
'
Sd&I:? quite high, no particular subgroup is systematically underserviced
%|@?)[; in terms of cataract surgery. Overall, the results of
_6FDuCVD- cataract surgery are very good, with the majority of eyes
Bptt" achieving driving vision following cataract extraction.
IAd^$9 Key words: cataract extraction, health planning, health
WV}pE~ services accessibility, prevalence
JKmd'
ZGw INTRODUCTION
)P1NX"A Cataract is the leading cause of blindness worldwide and, in
}J5iY0 Australia, cataract extractions account for the majority of all
oQyMs> g ophthalmic procedures.1 Over the period 1985–94, the rate
E3Z>R=s of cataract surgery in Australia was twice as high as would be
$o\Uq expected from the growth in the elderly population.1
kH=~2rwm Although there have been a number of studies reporting
UIQ=b;J9 the prevalence of cataract in various populations,2–6 there is
b(ryk./ogx little information about determinants of cataract surgery in
/C<} :R the population. A previous survey of Australian ophthalmologists
Rx<[bohio showed that patient concern and lifestyle, rather
h^9Ne/s~ than visual acuity itself, are the primary factors for referral
Q6Zh%\+h( for cataract surgery.7 This supports prior research which has
s|!b: Ms` shown that visual acuity is not a strong predictor of need for
-JF|770i cataract surgery.8,9 Elsewhere, socioeconomic status has
a7NX~9g been shown to be related to cataract surgery rates.10
_Q;M$.[zyR To appropriately plan health care services, information is
FH H2 needed about the prevalence of age-related cataract in the
6ud<B community as well as the factors associated with cataract
;Wr,VU] surgery. The purpose of this study is to quantify the prevalence
r3 {o_w of any cataract in Australia, to describe the factors
ZsPBs4<p
related to unoperated cataract in the community and to
K[TMTn describe the visual outcomes of cataract surgery.
.J\U|r METHODS
H"?
-&>V- Study population
J>Rt2K Details about the study methodology for the Visual
!c`Q?aGV) Impairment Project have been published previously.11
{ K0T%.G Briefly, cluster sampling within three strata was employed to
g9"_ BG recruit subjects aged 40 years and over to participate.
KF-gcRh Within the Melbourne Statistical Division, nine pairs of
.}y
Lz census collector districts were randomly selected. Fourteen
A8eli=W nursing homes within a 5 km radius of these nine test sites
yxQAO_C were randomly chosen to recruit nursing home residents.
)J88gMk+ Clinical and Experimental Ophthalmology (2000) 28, 77–82
izWl5}+'B Original Article
~O
6~',KD Operated and unoperated cataract in Australia
@x J^JcE Catherine A McCarty PhD, MPH, Mukesh B Nanjan PhD, Hugh R Taylor MD
(&hX8
Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
>a-+7{}; n Correspondence: Dr Cathy McCarty MPH, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne,
!<6wrOMa O Victoria 3002, Australia. Email:
cathy@cera.unimelb.edu.au )LhO}zQ 78 McCarty et al.
Y@\5gZ&T Finally, four pairs of census collector districts in four rural
g4$%)0x% Victorian communities were randomly selected to recruit rural
Sf'5/9<DW+ residents. A household census was conducted to identify
YXg
uw7%\ eligible residents aged 40 years and over who had been a
f}'gg resident at that address for at least 6 months. At the time of
kL|Y-(FPo% the household census, basic information about age, sex,
C[&&.w8Pm country of birth, language spoken at home, education, use of
;VFr5.*x corrective spectacles and use of eye care services was collected.
K]Cvk% Eligible residents were then invited to attend a local
*(MvNN* examination site for a more detailed interview and examination.
.XB] X The study protocol was approved by the Royal Victorian
t3>rf3v Eye and Ear Hospital Human Research Ethics Committee.
?W|IC8~d') Assessment of cataract
B;~agr A standardized ophthalmic examination was performed after
EDQJ>c pupil dilatation with one drop of 10% phenylephrine
_Usg`ax- hydrochloride. Lens opacities were graded clinically at the
9|WWA%p time of the examination and subsequently from photos using
*vO'Z & the Wilmer cataract photo-grading system.12 Cortical and
KUyJ"q<W posterior subcapsular (PSC) opacities were assessed on
h^*{chm] retroillumination and measured as the proportion (in 1/16)
8)!;[G| of pupil circumference occupied by opacity. For this analysis,
5l}h8So4 cortical cataract was defined as 4/16 or greater opacity,
NFc8"7Mz} PSC cataract was defined as opacity equal to or greater than
\-0` %k"& 1 mm2 and nuclear cataract was defined as opacity equal to
a&