ABSTRACT
92d6U2T4& Purpose: To quantify the prevalence of cataract, the outcomes
AUNQA of cataract surgery and the factors related to
(85Fv&a unoperated cataract in Australia.
i|}[A Methods: Participants were recruited from the Visual
C,NxE5?h Impairment Project: a cluster, stratified sample of more than
,FMx5$ 5000 Victorians aged 40 years and over. At examination
E V^~eTz sites interviews, clinical examinations and lens photography
$w0lrh[+ were performed. Cataract was defined in participants who
;9ly'<up had: had previous cataract surgery, cortical cataract greater
)aao[_ZS than 4/16, nuclear greater than Wilmer standard 2, or
>sjhA|gXk posterior subcapsular greater than 1 mm2.
/43-;"%> Results: The participant group comprised 3271 Melbourne
|'+eMl residents, 403 Melbourne nursing home residents and 1473
;w-qHha rural residents.The weighted rate of any cataract in Victoria
-,aeM~ was 21.5%. The overall weighted rate of prior cataract
O Xi@c;F surgery was 3.79%. Two hundred and forty-nine eyes had
"zY](P had prior cataract surgery. Of these 249 procedures, 49
"t$k (20%) were aphakic, 6 (2.4%) had anterior chamber
XfE -fH1j intraocular lenses and 194 (78%) had posterior chamber
c8M2 ^{O,` intraocular lenses.Two hundred and eleven of these operated
h:)Ci!D; eyes (85%) had best-corrected visual acuity of 6/12 or
G #T<`>T better, the legal requirement for a driver’s license.Twentyseven
|*X*n*oI (11%) had visual acuity of less than 6/18 (moderate
l|+BC vision impairment). Complications of cataract surgery
TLf9>=
OVh caused reduced vision in four of the 27 eyes (15%), or 1.9%
9F-
)r' of operated eyes. Three of these four eyes had undergone
-l-E_6|/W intracapsular cataract extraction and the fourth eye had an
-MugnB6
opaque posterior capsule. No one had bilateral vision
:!f(F9 impairment as a result of cataract surgery. Surprisingly, no
<0.$'M~E particular demographic factors (such as age, gender, rural
Lru-u: residence, occupation, employment status, health insurance
mNAY%Wn6k status, ethnicity) were related to the presence of unoperated
q7m6&2$[ cataract.
]PP:oriWl Conclusions: Although the overall prevalence of cataract is
%=<IGce quite high, no particular subgroup is systematically underserviced
c<BO gNr in terms of cataract surgery. Overall, the results of
W*:,m8wk cataract surgery are very good, with the majority of eyes
+P`(Rf"luu achieving driving vision following cataract extraction.
N_Af3R1_ Key words: cataract extraction, health planning, health
ixh47M services accessibility, prevalence
TfZ6F8|B INTRODUCTION
geefnb Cataract is the leading cause of blindness worldwide and, in
"%QD{z_L Australia, cataract extractions account for the majority of all
v)kEyX'K2d ophthalmic procedures.1 Over the period 1985–94, the rate
j#6|V]l of cataract surgery in Australia was twice as high as would be
mN5
8r"!J expected from the growth in the elderly population.1
i~{
_eQV Although there have been a number of studies reporting
l??;3kh1 the prevalence of cataract in various populations,2–6 there is
QldzQ%4c\ little information about determinants of cataract surgery in
nxap\Lf the population. A previous survey of Australian ophthalmologists
3Gr&p6 showed that patient concern and lifestyle, rather
\H5Jk$* than visual acuity itself, are the primary factors for referral
F[7x*-NO- for cataract surgery.7 This supports prior research which has
snp v z1iS shown that visual acuity is not a strong predictor of need for
7TX,
T|>9 cataract surgery.8,9 Elsewhere, socioeconomic status has
:Px\qh}K been shown to be related to cataract surgery rates.10
4`2$_T$F To appropriately plan health care services, information is
M\+* P,i needed about the prevalence of age-related cataract in the
W)SjQp6 community as well as the factors associated with cataract
g"!\\:M surgery. The purpose of this study is to quantify the prevalence
(%Oe_*e}Y of any cataract in Australia, to describe the factors
DcV<y-`'1 related to unoperated cataract in the community and to
XqR{.jF. describe the visual outcomes of cataract surgery.
ke.7Zp2.R METHODS
dNVv4{S Study population
d\XRUO[ Details about the study methodology for the Visual
t&814Uf&\ Impairment Project have been published previously.11
f@:CyB GQ Briefly, cluster sampling within three strata was employed to
cvAtw Q' recruit subjects aged 40 years and over to participate.
<qiICb)~ Within the Melbourne Statistical Division, nine pairs of
I Ru$oF} census collector districts were randomly selected. Fourteen
J/4y|8T/y nursing homes within a 5 km radius of these nine test sites
iWXMKu were randomly chosen to recruit nursing home residents.
d0C8*ifFO Clinical and Experimental Ophthalmology (2000) 28, 77–82
:+kUkb-/ Original Article
Xn7[n Operated and unoperated cataract in Australia
l6B.6
'4)w Catherine A McCarty PhD, MPH, Mukesh B Nanjan PhD, Hugh R Taylor MD
T=?
bdIl Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
z(d4)z 8'6 n Correspondence: Dr Cathy McCarty MPH, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne,
mMxHR$2 Victoria 3002, Australia. Email:
cathy@cera.unimelb.edu.au o#d$[oa 78 McCarty et al.
I>m;G
` Finally, four pairs of census collector districts in four rural
p6blD-v Victorian communities were randomly selected to recruit rural
E0bFx5e5fu residents. A household census was conducted to identify
*Pb.f eligible residents aged 40 years and over who had been a
V/
UB9)i+ resident at that address for at least 6 months. At the time of
<jL#>L%% the household census, basic information about age, sex,
m0iV m| country of birth, language spoken at home, education, use of
Pt3[|4L corrective spectacles and use of eye care services was collected.
z`9l<Q/ Eligible residents were then invited to attend a local
<<BQYU)Ig examination site for a more detailed interview and examination.
v =+k"gm6 The study protocol was approved by the Royal Victorian
J:W'cH$cR Eye and Ear Hospital Human Research Ethics Committee.
.5k^f5a Assessment of cataract
# 8qyg<F A standardized ophthalmic examination was performed after
vj@V
!j? pupil dilatation with one drop of 10% phenylephrine
s{% fi* hydrochloride. Lens opacities were graded clinically at the
n1`T#%e time of the examination and subsequently from photos using
&1$8q0 the Wilmer cataract photo-grading system.12 Cortical and
@{de$ODu posterior subcapsular (PSC) opacities were assessed on
j)<[j&OWw retroillumination and measured as the proportion (in 1/16)
ht$ WF of pupil circumference occupied by opacity. For this analysis,
wO\!xW: cortical cataract was defined as 4/16 or greater opacity,
"x.88,T6 PSC cataract was defined as opacity equal to or greater than
cl#OvQ 1 mm2 and nuclear cataract was defined as opacity equal to
JbVi1?c or greater than Wilmer standard 2,12 independent of visual
0wYiu acuity. Examples of the minimum opacities defined as cortical,
V'$oTZ` nuclear and PSC cataract are presented in Figure 1.
kOzt"t&