Post on 21-Jul-2016
ROP: Why More RelevantToday/Blindness Statistics
in Different Countries
6 Retinopathy of Prematurity: A Text and Atlas
Facts About Childhood Blindness
The control of blindness in children is oneof the priority areas of the World HealthOrganization’s VISION 2020—The Right toSight Program. This is a global initiative,which was launched by WHO in 1999 toeliminate avoidable blindness worldwide bythe year 2020. The priorities for control inthe first phase are cataract, onchocerciasis,trachoma and refractive errors and lowvision. Although blindness in children isrelatively uncommon, this age group isconsidered a priority as severe visual lossin children can affect their development,mobility, education and employment oppor-tunities, which can have far reaching impli-cations on the quality of life of children andthe affected families in developing countries.
The global estimate of children withsevere visual impairment and blindness (SVI/BL) in the world is 1.5 million, of whom 1million live in Asia.18
Childhood blindness is importantbecause it is either preventable or treatablein 50 to 70 percent of cases. The cumulativenumber of blind years lived by children (75million years) is second only to that due tocataract (125 million years) (Table 2.1).18
The 1991 census enumerated 314 million(37%) of India’s 850 million population asless than 16 years. An estimated childhoodblindness prevalence of 0.7 (+ 0.3)/1000 inIndia translates into 218,000 ( + 92,000) blindchildren, which is 4 to 5 times higher thanindustrialized countries.19 With the India’s2001 census total population being 1.02billion, of which 420 million (40.9%) are <16years, an estimated 300,000 children are
blind at present.20 Likewise about 19 percentof world’s blind children are in India.
Childhood blindness is a curse more soif it occurs immediately after birth. It isimportant not only in terms of economicburden but its severe social implication,which is very long in terms of blind years.Among the preventable causes of blindnessin children, which is 57 percent, Retinopathyof Prematurity (ROP) figures very high inthe agenda. Since 22 percent of all blindchildren have retinal causes, ROP is amongstthe first few in high and middle incomegroup countries (Table 2.2).
Nevertheless occurrences of ROP in lowincome group has been largely unnoticedand attributable to a so called ‘first epidemic’which resulted due to insufficient oxygenadministration, i.e. unmonitored oxygenlevels in the absence of better life-supportingsystems. In the context of our country weare sitting on the summit of two volcanoes—one where all latest state of art health careis available, i.e. mainly in metropolis andthe other where even minimal basic healthcare is unavailable. ROP is known to growin both these conditions and therefore tohave any estimate regarding ROP will bean underestimate.
Available figures for blinding and statisticsare depressive and yet challenging varyingfrom 2.3 to 3.35 percent of all prematurechildren. Coming on to risk factors, low birthweight and low gestational age are the twoimportant vectors which govern which childwill develop ROP and which will not. In termsof birth weight, children less than 1500 gmhave almost 20 to 50 percent chance of develop-
ROP: Why More Relevant Today/Blindness Statistics in Different Countries 7
Tabl
e 2.
1: M
ajor
cau
ses
of c
hild
hood
blin
dnes
s by
Wor
ld B
ank
econ
omic
reg
ions
(bas
ed o
n da
ta fr
om b
lind
scho
ol s
tudi
es)18
Wor
ld B
ank
regi
onE
stim
ated
num
ber
Cau
se 1
Cau
se 2
Cau
se 3
Cau
se 4
of b
lind
child
ren
1998
Afr
ica
320,
000
Cor
neal
sca
rR
etin
al d
ystr
ophy
Cat
arac
t/gl
auco
ma
Opt
ic a
trop
hy
Indi
a27
0,00
0C
orne
al s
car
Ano
mal
ies
Ret
inal
dys
trop
hyC
atar
act/
glau
com
a
Res
t of
Asi
a22
0,00
0R
etin
al d
ystr
ophy
Cor
neal
sca
rC
atar
act/
glau
com
aR
OP
Chi
na20
0,00
0?
??
?
Mid
dle
East
190,
000
Ret
inal
dys
trop
hyC
atar
act/
glau
com
aA
nom
alie
sC
orne
al s
car
Lat
in A
mer
ica
100,
000
RO
PR
etin
al d
ystr
ophy
Cat
arac
t/gl
auco
ma
Tox
opla
smos
is
Esta
blis
hed
50,0
00C
NS
lesi
ons
Ret
inal
dys
trop
hyR
OP
Cat
arac
t/gl
auco
ma
Eco
nom
ies
Eas
tern
Eur
ope
40,0
00R
etin
al d
ystr
ophy
Cat
arac
t/gl
auco
ma
Ano
mal
ies
RO
P
8 Retinopathy of Prematurity: A Text and Atlas
ing any stage of ROP and 7 to 16 percentchance of developing threshold ROP orblinding ROP. These figures are from threemajor centers in India, i.e. Delhi, Bangaloreand Chennai. A very low gestational age (<28weeks) again compounds the risk ofdeveloping threshold ROP or blinding ROPof a very severe grade. Low incidence of ROP
Table 2.2: Avoidable causes of childhood blindness by World Bank region(based on data from blind school studies)18
World Bank region Corneal scar Cataract ROP Total
Africa 100,000 30,000 < 1,000 130,000
India 90,000 30,000 < 1,000 120,000
Rest of Asia 60,000 30,000 < 5,000 90,000
China 25,000 12,000 < 1,000 37,000
Middle East ?25,000 ?20,000 < 1,000 ?45,000
Latin America 10,000 8,000 25,000 43,000
Established 2,000 10,000 < 5,000 15,000economies
Eastern Europe < 1,000 3,000 6,000 10,000
Total 310,000 140,000 40,000 500,000
in India is basically due to (a) low or nosurvival rate of children <12,00 gm in rural/semiurban settings (b) cases of IUGRpresenting commonly in view of low nutritionand anemia amongst Indian mothers, (c)unawareness amongst ophthalmologists andneonatologists, and (d) lack of experienceand infrastructure for ROP screening.