Vol.14
No. 1, Januray, 2004
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.
