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.