Uncorrected Refractive Errors in
Urban School Children
CS Dhull, SV Singh, Malay Verma,
Manju Hooda, Vedpal
Uncorrected refractive errors are
the second most common cause of
preventable bilateral blindness in
India. According to 1989 National
Survey of Blindness, 7.35% persons
had blindness due to refractive
errors. Children account for 40% of
the population and refractive errors
are quite common in them.1
The symptoms of refractive errors
are quite variable in presentation
as well as in severity. Refractive
error go largely undetected even in
urban areas due to low awareness.
This study was carried out to study
the prevalence of refractive errors
in school children of urban areas
which have got access to tertiary
medical care.
MATERIAL AND METHODS
Three schools in Rohtak city were
selected for this study at random.
678 students belonging to age group
5-10 years were included in this
study. Children already using
spectacles were not included in the
study. Visual acuity of all the
students was estimated on Snellen's
distance vision charts (alphabets)
in the school premises itself. A
cut off of 6/9 line was kept. All
the students having vision 6/9 were
referred to OPD, Department of
Ophthalmology, Pt. B.D. Sharma,
PGIMS, Rohtak. Refraction under
cycloplegic was carried out to
achieve best corrected visual
acuity. Myopia was defined as
spherical equivalent rafractive
error of at least -0.5D, hyperopia
as +2.0D or more and astigmatism as
cylinder of more than 0.5D3. Colour
vision estimation was done at
schools using Ishihara's
pseudoisochromatic charts.
RESULTS
A total of 678 students were
examined. Out of these 83 (12.42%)
were not able to see 6/9 line on
Snellen's distance visual acuity
chart with one or both eyes and were
referred. One static retinoscopy, 76
of these students had
refractiveerror whereas 7 had normal
retinoscopic pattern bringing the
overall prevalence of uncorrected
refractive error to 11.37%.
Hyperopia was present in 5.14% of
children, myopia in 3.23% and
astigmatism in 3% of children.
Colour vision deficiency was seen in
1.2% of subjects and most of them
were total colour blind.
DISCUSSION
Refractive errors are important
contributor to preventable
blindness. The prevalence of
uncorrected refractive errors as
estimated by Murthy et al in urban
areas of Delhi was 6.4%2.
Prevalence of hyperopia, myopia and
astigmatism determined by Kalikivayi
et al in school children of Souch
Indian as 22.6%, 8.6% and 10.3%
respectively which is quite high
from the values achieved in our
study3. Dandona et al
estimated the prevalence to be
4.4%. 59.37% and 6.93% respectively4.
As we had included subjects of lower
age group so our results
particularly on myopia do not tally.
Knowledge about the distribution and
demographic association of
refractive errors can help in better
planning of eye care services.
Presence of such a significant
amount of undetected refractive
errors in an urban area which has
got easy access to tertiary medical
care suggest using alternative
strategies. Schools can be involved
in screening for refractive errors
thus facilitating early diagnosis
and treatment.
REFERENCES
-
Limburg H, Vaidyanathan R, Dalal
HP. Cost effective screening of
school children for refractive
errors. World Health Forum,
1995;16:173-8.
-
Murthy GVS, Gupta SK, Ellwein LB
Munoz SR, Pokharel G, Sanga L et
al. Refractive errors in
children in an urban population
in New Delhi. IOVS
2002;43:623-31.
-
Kalikivayi V, Naduvilath TJ,
Bansal AK, Dandona L. Visual
impairment in school children in
South India. Ind J. Ophthalmol
1997;45(2):129-34.
-
Dandona R, Naduvilath TJ,
Dandonal, Srinivas M, Mc Carty
CA, Rao GN. Refractive errors in
an urban population in Southern
India. The Andhra Pradesh Eye
Disease Study. IOVS 1999;
40:2810-2818.
Address
for Correspondence
Dr. C.S. Dhull, Deptt. of
Ophthalmology,
Pt. BD Sharma PGIMS, Rohtak.
