Dr.Amit Mohan, M11516, Dr. Anita Bisht, Dr. Vinod
Kumar Sharma, Dr. Zeeshan Jami
Authors : Dr Anita Bisht, Dr V.K.Sharma, Dr Amit Mohan, Dr Zeeshan Jamil
Institute : Global Hospital Istitute Of Ophthalmology, Abu road, Rajasthan
Introduction
Visual impairment is a worldwide problem that has a significant socioeconomic impact. There are several disorders that cause substantial impairment of vision but are relatively asymptomatic in very small and even in older children and may thus be missed by the parents. Screening for these disorders which are ‘silent’ in manifestation but for which timely intervention is effective should be specifically identified by Screening Programs.
Childhood blindness is a priority area because of the number of years of blindness that ensues. Data on prevalence and causes of blindness and severe visual impairment in children are needed for planning and evaluating preventive and curative services for children, including planning special education and low vision services. It is estimated that 1.5 million children suffer from Severe Visual Impairment and Blindness and of these 1 million live in Asia alone.1 It is estimated that 1 child goes blind in every 5 minutes.1 Fortunately,75% of this blindness is infact treatable and/or preventable.1 The cumulative number of blind-years lived by children is calculated to be 75 million which is almost equal to the number of blind years due to cataract in adults.1,2 The available data suggest that there may be a tenfold difference in prevalence between the wealthiest countries of the world and the poorest, ranging from as low as 0.1/1000 children aged 0-15 years in the wealthiest countries to 1.1/1000 children in the poorest.3 Considering the fact that the 30% of India’s blind lose their eyesight before the age of 20 years and many of them are under five when they become blind ,the importance of early detection and treatment of ocular disease and visual impairment among young children is obvious.4 Children do not complain of defective vision, and may not even be aware of their problem. They adjust to the poor eyesight by sitting near the blackboard, holding the books closer to their eyes, squeezing the eyes and even avoiding work requiring visual concentration, this warrants early detection and treatment to prevent permanent disability. Effective methods of vision screening in school children are useful in detecting correctable causes of decreased vision, especially refractive errors and in minimizing long-term visual disability.4 Children in the school-going age group (6-14 years) represent 25% of the population in the developing countries. They offer significantly representative material for this study as they fall best in the preventable blindness age group, are a controlled population i.e. they belong to a certain age group and are easily accessible and schools are the best forum for imparting health education to the children. Schools are also one of the best centers for effectively implementing the comprehensive eye healthcare program.4 Hence, this study was conducted with the objective of estimating the prevalence of ocular morbidity among school children.
There is a distinction between screening and a screening program. Screening is a process of acquiring significant data about a population. A screening program is not just a process of diagnosing vision problems, but it uses the collected data to refer children with possible problems for further evaluation and treatment. The distinguishing feature between the two is thus intervention, which is an essential component of a screening program. Intervention in the school setting might include adapting the school program to meet the student’s needs if a problem cannot or has not been corrected.5 The success of any screening program ultimately depends upon securing the cooperation of school personnel, the child, the parents, the eye care practitioner, and others who may be involved.
Recommendations for screening of children for following eye diseases.1
- Refractive error
- Amblyopia
- Congenital cataract
- Strabismus
- Corneal blindness
- Ptosis
Aims and Objectives
- To assess the role of school screening camps in identifying children with ocular morbidity.
- To assess improvement in visual acuity following spectacle prescription for refractive error with patching in amblyopic children and following pediatric ocular surgery.
Materials and Methods
Site of study:
Cross-sectional study was conducted at different primary and secondary schools at Jallore, Sirohi, Pali, Jodhpur, Jaisalmer and Barmer districts of Rajasthan under ‘Sarva Siksha Abhiyaan’ project and Pediatric ocular surgery was done at base hospital, Global hospital institute of Ophthalmology [GHIO].
Study design:
Cross-sectional study.
Duration of study:
The study was conducted over a period of 1 year from 01 Oct’2013 upto Oct’2014.
Selection of Cases:
The study group consists of children of age group 6-14 years of different schools.
Methods and data collection:
The camp screening equipment consists of vision trial box with “E” vision chart, ophthalmoscope, streak retinoscope, magnifying loupe and portable slit lamp. Assessment for refraction was performed in all children.
The screening is carried out in the following way:
From a distance of six meters (measured with the tape provided), child is shown the vision card, which is white with four black “Es” of standard size (6/9 of Snellen’s chart). For each eye, child has to indicate the direction of the open end of the “E”. Children of age <8years, especially in government schools, were shown picture charts for vision testing. Any child having visual acuity of 6/9 or worse was examined for refractive error. Retinoscopy and subjective refraction was done for all the patients suspected of having refractive error. Cycloplegic refraction was done at base hospital for children having refractive error and glasses were prescribed.
If amblyopia was found then patching 4hours/day while doing near work along with refractive error correction was told and asked for follow-up at 2weeks, 1month, 3month and 6month.Visual improvement following patching and glass prescription was assessed at 6th month of follow-up.
Extra ocular movements, Hirschberg test, cover-uncover test for detection of squint was done and if squint was present then child was referred to base hospital for further evaluation and for surgery if required. Those children who had undergone strabismus surgery were evaluated for binocularity at one month postoperatively.
Anterior segment examination was performed using a torch, magnifying loupe, and/or slit lamp.
The posterior segment examination was done after dilating the pupil, where indicated, using a direct and/or indirect ophthalmoscope.
A major anatomical site and underlying cause was selected for each eye, and for each child.
For each child, the need for optical, surgical, or medical interventions was recorded and the expected visual prognosis assessed.
Congenital cataract was evaluated by direct ophthalmoscope slit lamp
examination and then referred to base hospital Those who had undergone cataract IOL surgery were postoperatively evaluated for visual outcome at first week, 4th week and 6th month postoperatively.
Children with ptosis or corneal blindness were also referred to base hospital for further evaluation and those who had undergone surgery for ptosis were postoperatively evaluated for visual outcome at first week, 4th week and 6th month postoperatively.
For all the analysis, children of 6-14 years were divided into 4 groups–
- First group is 6-8 years of age group children
- Second group is 8-10 years of age group children
- Third group is 10-12 years of age group children
- Fourth group is 12-14 years of age group children
Inclusion criteria :
- Children of age-group 6-14 years.
- Children who were present on the day of screening in their school were
- Children who need surgery were included only if their parents had given consent for the surgery .
Exclusion criteria :
- Children below 6 years or above 14 years.
- Previously diagnosed and treated children.
Ethical clearance:
The Institutional Ethics Committee on Human Subjects Research, 2013-2014, granted approval, subsequent to which data collection for the study was initiated.
Statistical analysis :
Descriptive statistical analysis has been carried out in the present study andresults on categorical measurements are presented in a number(%). The relative risk (RR) and its standard error are calculated according to Altman, 1991.The relative risk or risk ratio is given by
With the standard error of the log relative risk being
Where zeros cause problem with computation of the relative risk or its standard error, 0.5 is added to all cells (a, b, c, d).
and 95% confidence interval
Where zeros cause problem with computation of the relative risk or its standard error, 0.5 is added to all cells (a, b, c, d).
P<0.05 was taken as significant.
Statistical software:
The statistical software, statistical product and service solutions (SPSS 15.0) wasused for the analysis of the data and Microsoft word and Excel have been used togenerate graphs, tables, etc.
Results
A total of 16800 children of age 6-14 years were enrolled from elementary through tenth class in the schools allotted in ‘Sarva Siksha Abhiyaan’ in six districts (Sirohi, Pali, Jallore, Jodhpur, Jaiselmer, Barmer) of Rajasthan. Out of these, 632 children could not be contacted because they were absent on the day of screening in that particular school. Hence, a total of 16168 school children were examined for ocular morbidity. Boys 8344(51.60%) and girls 7824(48.40%) had almost equal representation.
Overall prevalence of ocular morbidity among school children of age 6-14 years was 5104(31.6%) [ Table 1].
Refractive errors 1664 (32.6%) constitute the major cause of ocular morbidity followed by congenital disorders 704 (13.8%), Vitamin-A deficiency 424(8.3%) , allergy 392 (7.7%), cataract 296 and squint 288 constitute almost similar proportion (5.6%) of total ocular morbidity, corneal opacity 168 (3.3%), and ptosis 32(0.6%) [Table 2].
Table 1
| n=16168 | % | |
| Normal | 11064
|
68.4 |
| Total morbidity |
5104 |
31.6 |
Table 2
| Total | % | ||
| Refractive error | 1664 | 32.6 | |
| Cataract | 296 | 5.8 | |
| Squint | 288 | 5.6 | |
| Corneal opacity | 168 | 3.3 | |
| Congenital disorders | 704 | 13.8 | |
| Vitamin A deficiency | 424 | 8.3 | |
| Allergy | 392 | 7.7 | |
| Ptosis | 32 | 0.6 | |
| Others | 1136 | 22.2 | |
| Conjunctivitis | 452 | 39.8 | |
| Blepharitis | 116 | 10.2 | |
| Stye | 124 | 10.9 | |
| Cholazian | 112 | 9.9 | |
| Colour blindness | 248 | 21.8 | |
| One eyed | 84 | 7.4 | |
Figure 1: Prevalence of ocular morbidity among 6-14 years age group children
Sex-wise distribution of ocular morbidity
Overall prevalence of ocular morbidity was more among boys(35.9%) as compared to girls(27.0%) which was statistically significant(p<0.05) [Table 3].
Among both girls and boys, refractive error constitute the major cause of ocular morbidity (girls 9.0% and boys 11.5%) which is statistically significant (p<0.05).
Among boys prevalence of cataract was 2.5% , of squint is 2.2%, of Vitamin A deficiency 3.3% and of ptosis 0.3% which is greater than prevalence among girls of cataract 1.1%, squint 1.3%, Vitamin A deficiency 1.9% and ptosis 0.1% respectively.
Almost equal sex prevalence of corneal opacity (girls 1.0% and boys 1.1%), of congenital disorders (girls 3.9% and boys 4.8%) and of allergy (girls 2.6% and boys 2.3%) was found.
Table 3
| ex-wise distribution of ocular morbidity | |||||
| Girls %
n=7824 |
Boys %
n=8344 |
Relative
Risk |
p value | ||
| Refractive error | 9.0 | 11.5 | 0.9 | <0.0001 | |
| Cataract | 1.1 | 2.5 | 0.6 | <0.0001 | |
| Squint | 1.3 | 2.2 | 0.7 | 0.0002 | |
| Corneal opacity | 1.0 | 1.1 | 0.9 | 0.8415 | |
| Congenital disorders | 3.9 | 4.8 | 0.9 | 0.0070 | |
| Vitamin A deficiency | 1.9 | 3.3 | 0.7 | <0.0001 | |
| Allergy | 2.6 | 2.3 | 1.0 | 0.2796 | |
| Ptosis | 0.1 | 0.3 | 0.5 | 0.0308 | |
| Others | 6.0 | 8.0 | 0.9 | <0.0001 | |
| Total morbidity | 27.0 | 35.9 | 0.8 | <0.0001 | |
Age-wise distribution of ocular morbidity
Overall prevalence of ocular morbidity was highest (40.9%) among 12-14 years age group students [Table 4] then among 8-10 years (31.3%) age group students and almost equal prevalence of ocular morbidity among 6-8 years (24.8%) and 10-12 years (22.2%) age group of students.
But, prevalence of refractive error increased significantly with age (6-8 years 5.1%, 8-10 years 6.2%, 10-12 years 7.5%, 12-14 years 16.1%). Prevalence of refractive error almost becomes doubles (16.1%) among 12-14 years age group students.
Prevalence of cataract was highest in 6-8 years age group (3.5%) followed by 8-10 years age group (2.6%), 12-14 years age group (1.8%) and 10-12 years age group (0.7%).
Prevalence of squint was highest in 8-10 years age group (3.3%) followed by 12-14 years age group (1.9%) and almost equal prevalence in 6-8 years age group (0.8%) and 10-12years age group (1.0%).
Prevalence of corneal opacity in 6-8 years age group (1.2%), 8-10 years age group (1.0%), 10-12 years age group (0.5%) and 12-14 years age group (1.4%).
Prevalence of congenital disorders was highest in 8-10 years age group and 12-14 years age group (5.2%) followed by 6-8 years age group (4.3%) and 10-12 years age group (2.8%).
Prevalence of Vitamin A deficiency was almost equal in all age group children (almost 3.0%).
Prevalence of allergy in 6-8 years age group (0.4%), 8-10 years age group (2.6%), 10-12 years age group (2.9%) and 12-14 years age group (2.7%).
Prevalence of ptosis was found in 8-10 years age group (0.3%) and 12-14 years age group (0.4%).
Table 4
| Age-wise distribution of ocular morbidity
|
||||
| 6-8 years
n=2032 % |
8-10 years
n=3120 % |
10-12 years
n=4720 % |
12-14 years
n=6296 % |
|
| Refractive error | 5.1 | 6.2 | 7.5 | 16.1 |
| Cataract | 3.5 | 2.6 | 0.7 | 1.8 |
| Squint | 0.8 | 3.3 | 1.0 | 1.9 |
| Corneal opacity | 1.2 | 1.0 | 0.5 | 1.4 |
| Congenital disorders | 4.3 | 5.2 | 2.8 | 5.2 |
| Vitamin A deficiency | 2.8 | 2.6 | 2.9 | 2.5 |
| Allergy | 0.4 | 2.6 | 2.9 | 2.7 |
| Ptosis | 0 | 0.3 | 0 | 0.4 |
| Others | 6.7 | 7.7 | 4.1 | 9.0 |
| Total morbidity | 24.8 | 31.3 | 22.2 | 40.9 |
| Normal | 75.2 | 68.7 | 77.8 | 59.1 |
Age-wise distribution of ocular morbidity among girls
Overall prevalence of ocular morbidity among girls [Table 5] was highest (34.0%) in 12-14 years age group and lowest (18.1%) in 10-12 years age group, while similar prevalence is found among 6-8 years and 8-10 years age group of girls.
Prevalence of refractive error as an ocular morbidity increased significantly with age among girls also (6-8 years 5.2%, 8-10 years 4.7%, 10-12 years 5.8%, 12-14 years 14.8%) as was seen with total including both boys and girls.
Prevalence of cataract among girls in 6-8 years age group (3.8%), 8-10 years age group (1.6%), 10-12 years age group (0.0%) and 12-14 years age group (0.8%).
Prevalence of squint among girls was highest in 8-10 years age group (2.6%) than 6-8 years age group (1.5%), 10-12 years age group (1.1%) and 12-14 years age group (0.8%).
Prevalence of corneal opacity among girls in 6-8 years age group (0.8%), 8-10 years age group (0.5%), 10-12 years age group (0.7%) and 12-14 years age group (1.6%).
Prevalence of congenital disorder among girls was highest in 8-10 years age group (5.8%) followed by 6-8 years age group (4.5%), 10-12 years age group (3.7%) and lowest in 10-14 years age group (2.9%).
Prevalence of Vitamin A deficiency among girls was almost same in all the age groups (approximate 2.0%).
Prevalence of allergy among girls was highest in 12-14 years age group (3.7%) followed by 8-10 years age group (2.6%) and 10-12 years age group (2.2%).
Prevalence of ptosis in 12-14 years age group was 0.3% and no case of ptosis in other age group girls.
Table 5
| Age-wise distribution of ocular morbidity among girls | ||||
| 6-8 years
n=1064 % |
8-10 years
n=1520 % |
10-12 years
n=2208 % |
12-14 years
n=3032 % |
|
| Refractive error | 5.3 | 4.7 | 5.8 | 14.8 |
| Cataract | 3.8 | 1.6 | 0 | 0.8 |
| Squint | 1.5 | 2.6 | 1.1 | 0.8 |
| Corneal opacity | 0.8 | 0.5 | 0.7 | 1.6 |
| Congenital disorders | 4.5 | 5.8 | 3.7 | 2.9 |
| Vitamin A deficiency | 2.3 | 2.1 | 1.5 | 2.1 |
| Allergy | 0 | 2.6 | 2.2 | 3.7 |
| Ptosis | 0 | 0 | 0 | 0.3 |
| Others | 7.5 | 6.8 | 3.3 | 7.1 |
| Total morbidity | 25.6 | 26.8 | 18.1 | 34.0 |
| Normal | 74.4 | 73.2 | 81.9 | 65.9 |
Age-wise distribution of ocular morbidity among boys
Overall prevalence of ocular morbidity among boys [Table 6] was highest (47.3%) in 12-14 years age group and then in 8-10 years age group (35.5%) with almost equal prevalence of ocular morbidity in 6-8 years and 10-12 years age group (24.0%).
Prevalence of refractive error as an ocular morbidity increased significantly with age among boys also (6-8 years 5.0%, 8-10 years 7.5%, 10-12 years 8.9%, 12-14 years 17.4%) as was seen with total including both boys and girls.
Prevalence of cataract among boys in 6-8 years age group (3.3%), 8-10 years age group (3.5%), 10-12 years age group (1.3%) and 12-14 years age group (2.7%).
Prevalence of squint was highest in 8-10 years age group (4.0%) followed by12-14 years age group (2.9%) and 10-12 years age group (0.9%).
Prevalence of corneal opacity among boys in 6-8 years age group (1.7%), 8-10 years age group (1.5%), 10-12 years age group (0.3%) and 12-14 years age group (1.2%).
Prevalence of congenital disorders was highest in 12-14 years age group (7.3%) followed by almost equal prevalence in 6-8 years age group and 8-10 years age group (4.5%) and 10-12 years age group (1.9%).
Prevalence of Vitamin A deficiency was highest in 10-12 years age group (4.1%) followed by almost equal prevalence in 6-8 years age group and 8-10 years age group (3.4%) and least in 12-14 years (2.6%).
Prevalence of allergy was highest in 10-12 years age group (3.5%) followed by 8-10 years age group (2.5%), 12-14 years age group (1.7%) and 6-8 years age group (0.8%).
Equal prevalence of ptosis in 8-10 years age group and 12-14 years age group (0.5%).
Table 6
| Age-wise distribution of ocular morbidity among boys | ||||
| 6-8 years
n=968 % |
8-10 years
n=1600 % |
10-12 years
n=2512 % |
12-14 years
n=3264 % |
|
| Refractive error | 4.9 | 7.5 | 8.9 | 17.4 |
| Cataract | 3.3 | 3.5 | 1.3 | 2.7 |
| Squint | 0 | 4.0 | 0.9 | 2.9 |
| Corneal opacity | 1.7 | 1.5 | 0.3 | 1.2 |
| Congenital disorders | 4.2 | 4.5 | 1.9 | 7.3 |
| Vitamin A deficiency | 3.4 | 3.0 | 4.1 | 2.6 |
| Allergy | 0.8 | 2.5 | 3.5 | 1.7 |
| Ptosis | 0 | 0.5 | 0 | 0.5 |
| Others | 5.8 | 8.5 | 4.8 | 10.8 |
| Total morbidity | 24.0 | 35.5 | 25.8 | 47.3 |
| Normal | 76.0 | 64.5 | 74.2 | 52.7 |
Sex-wise distribution of ocular morbidity among 6-8 years
Among 6-8 years age group students [Table 7], almost equal prevalence of ocular morbidity (24.0%) was found in girls and boys.
However, prevalence of squint was significantly (p<0.05) more among girls (1.5%) as compared to boys (0.0%).Almost equal prevalence of refractive error, cataract and congenital disorders was found among girls and boys.
Prevalence of corneal opacity (1.7%), Vitamin-A deficiency (3.4%) and allergy (0.8%) was more among boys as compared to girls.
Table 7
| Sex-wise distribution of Ocular morbidity
among 6-8 years students |
||||
| Girls
n=1064, % |
Boys
n=968, % |
Relative risk
|
P
Value
|
|
| Refractive error | 5.3 | 4.9 | 1.0 | 0.7522 |
| Cataract | 3.8 | 3.3 | 1.1 | 0.5680 |
| Squint | 1.5 | 0 | 1.9 | <0.0001 |
| Corneal opacity | 0.8 | 1.7 | 0.6 | 0.1152 |
| Congenital disorders | 4.5 | 4.2 | 1.0 | 0.6682 |
| Vitamin A deficiency | 2.3 | 3.4 | 0.8 | 0.1872 |
| Allergy | 0 | 0.8 | 0.1 | 0.1021 |
| Ptosis | 0 | 0 | 0 | |
| Others | 7.5 | 5.8 | 1.1 | 0.0952 |
| Total morbidity | 25.6 | 24.0 | 1.0 | 0.3999 |
| Normal | 74.4 | 76.0 | ||
Sex-wise distribution of ocular morbidity among 8-10 years
Among 8-10 years age group students [Table 8], prevalence of ocular morbidity was more in boys (35.5%) as compared to girls (26.9%) which was significant (p<0.05).
Prevalence of refractive error(7.5%), cataract(3.5%),squint(4.0%) and corneal opacity(1.5%) was more in boys as compared to girls which was significant (p<0.05). Prevalence of Vitamin-A deficiency(3.0%) was also more in boys as compared to girls but not significant. However, prevalence of congenital disorders was more among girls (5.8%) as compared to boys (4.5%).Equal prevalence of allergy (2.5%) among girls and boys.
Table 8
| Sex-wise distribution of Ocular morbidity
among 8-10 years students |
||||
| Girls
n=1520,% |
Boys
n=1600,% |
Relative risk
|
P
Value
|
|
| Refractive error | 4.7 | 7.5 | 0.8 | 0.0036 |
| Cataract | 1.6 | 3.5 | 0.6 | 0.0040 |
| Squint | 2.6 | 4 | 0.8 | 0.0521 |
| Corneal opacity | 0.5 | 1.5 | 0.5 | 0.0284 |
| Congenital disorders | 5.8 | 4.5 | 1.1 | 0.0830 |
| Vitamin A deficiency | 2.1 | 3 | 0.8 | 0.1440 |
| Allergy | 2.6 | 2.5 | 1.0 | 0.8140 |
| Ptosis | 0 | 0.5 | 0.1 | 0.1138 |
| Others | 6.8 | 8.5 | 0.9 | 0.0975 |
| Total morbidity | 26.8 | 35.5 | 0.8 | <0.0001 |
| Normal | 73.2 | 64.5 | ||
Sex-wise distribution of ocular morbidity among 10-12 years
Among 10-12 years age group students [Table 9], prevalence of ocular morbidity was more in boys (25.8%) as compared to girls (18.1%) which was significant (p<0.05). Prevalence of refractive error(8.9%), cataract(1.3%), Vitamin-A deficiency(4.1%) and allergy(3.5%) was more in boys as compared to girls which was significant (p<0.05).
Prevalence of congenital disorders (girls 3.7% and boys 1.9%) and corneal opacity (girls 0.7% and boys 0.3%) was significantly (p<0.05) more among girls as compared to boys. Prevalence of squint was also more in girls (1.1%) as compared to boys(0.9%) but not significant.
Table 9
| Sex-wise distribution of Ocular morbidity
among 10-12 years students |
||||
| Girls
n=2208,% |
Boys
n=2512, % |
Relative
Risk
|
P
Value
|
|
| Refractive error | 5.8 | 8.9 | 0.8 | 0.0002 |
| Cataract | 0 | 1.3 | 0.1 | 0.0143 |
| Squint | 1.1 | 0.9 | 1.1 | 0.6430 |
| Corneal opacity | 0.7 | 0.3 | 1.4 | 0.0141 |
| Congenital disorders | 3.7 | 1.9 | 1.3 | <0.0001 |
| Vitamin A deficiency | 1.5 | 4.1 | 0.5 | <0.0001 |
| Allergy | 2.2 | 3.5 | 0.8 | 0.0136 |
| Ptosis | 0 | 0 | ||
| Others | 3.3 | 4.8 | 0.8 | 0.0152 |
| Total morbidity | 18.1 | 25.8 | 0.8 | <0.0001 |
| Normal | 81.9 | 74.2 | ||
Sex-wise distribution of ocular morbidity among 12-14 years
Among 12-14 years age group students [Table 10], prevalence of ocular morbidity was more in boys (47.3%) as compared to girls (34.0%) which was significant (p<0.05).
Prevalence of refractive error(17.4%), cataract(2.7%), squint(2.9%) and congenital disorders(7.3%) was more in boys as compared to girls which was significant (p<0.05). Prevalence of allergy was significantly (p<0.05) more among girls (3.7%) as compared to boys (1.7%). Almost equal prevalence of corneal opacity(girls 1.6% and boys 1.2%), Vitamin-A deficiency(girls 2.1% and boys 2.6%) and ptosis (girls 0.3% and boys 0.5%) was found among girls and boys of 12-14 years of age group.
Table 10
| Sex-wise distribution of Ocular morbidity
among 12-14 years students |
||||
| Girls
n=3032, % |
Boys
n=3264, % |
Relative
Risk
|
P
Value
|
|
| Refractive error | 14.8 | 17.4 | 0.9 | 0.0061 |
| Cataract | 0.8 | 2.7 | 0.4 | <0.0001 |
| Squint | 0.8 | 2.9 | 0.4 | <0.0001 |
| Corneal opacity | 1.6 | 1.2 | 1.1 | 0.1979 |
| Congenital disorders | 2.9 | 7.3 | 0.5 | <0.0001 |
| Vitamin A deficiency | 2.1 | 2.6 | 0.9 | 0.1524 |
| Allergy | 3.7 | 1.7 | 1.4 | <0.0001 |
| Ptosis | 0.3 | 0.5 | 0.7 | 0.2015 |
| Others | 7.1 | 10.8 | 0.8 | <0.0001 |
| Total morbidity | 34.0 | 47.3 | 0.8 | <0.0001 |
| Normal | 66.0 | 52.7 | ||
Visual assessment of amblyopic children who were prescribed glasses and/ or Advised patching
Total number of refractive error was 1664.Out of which 884 were myopic, 532 were hyperopic and 248 were astigmatics. [Table 11]
Table 11
| Causes of refractive error | ||
| Unilateral | Bilateral | |
| Myopia | 352 (39.8%) | 532 (60.2%) |
| Hyperopia | 217 (40.8%) | 315 (59.2%) |
| Astigmatism | 152 (61.3%) | 96 (38.7%) |
Total number of amblyopic children were 162. Among different causes of amblyopia, refractive error (81.9%) constitute the main cause of amblyopia and out of refractive error, anisometropia (65.9%) was the main cause.[Table 12]
Table 12
| Causes of amblyopia | |
| Isoametropia | 26 (15.9%) |
| Anisometropia | 106(65.9%) |
| Strabismus | 18(11.1%) |
| Others | 12(7.4%) |
Total number of children who were prescribed glasses with patching were 156 out of 162 amblyopic children who were screened at different schools.
All patients were followed up at 2 week , 1month, 3month and 6month.
Table 13 include children who came to follow-up at 6th month which were 144
while remaining 12 patients were dropped out.
|
||||||||||||||||||||||||
first visit, maximum percentage (42.6%) of amblyopic eyes were having visual acuity of <6/24-6/60 while minimum percentage (1.06%) with visual acuity of <3/60-PL. However at 6th month of follow-up, there was improvement in visual acuity with maximum percentage(45.5%) of children having vision between 6/6-6/12 with a shift in percentage of amblyopic eyes towards improved visual acuity(27.3% of children having vision between <6/12-6/24, 19.9% of children having vision between <6/24-6/60, 6.9% of children having vision between <6/60-3/60 and 0.0% of children having vision between <3/60-PL) .
Table 13
| V.A category | Total number of eyes (%) | |
| At first visit | At 6th month | |
| (6/6-6/12) | 0 | 324(45.5%) |
| <6/12-6/24 | 162(21.5%) | 205(27.3%) |
| <6/24-6/60 | 320(42.6%) | 150(19.9%) |
| <6/60-3/60 | 262(34.8%) | 52(6.9%) |
| <3/60-PL | 8(1.06%) | 3(0.4%) |
| Total | 752 | 752 |
Table 11
| V.A category | Total number of eyes (%) | |
| At first visit | At 6th month | |
| (6/6-6/12) | 0 | 66(45.5%) |
| <6/12-6/24 | 31(21.5%) | 39(27.3%) |
| <6/24-6/60 | 61(42.6%) | 29(19.9%) |
| <6/60-3/60 | 50(34.8%) | 10(6.9%) |
| <3/60-PL | 2(1.06%) | 0 |
| Total | 144 | 144 |
Figure 3: Visual assessment following glass prescription with patching in amblyopic children
Visual assessment in patient who underwent cataract surgery
A total of 181 eyes of 102 patients underwent surgery, 95 surgeries were performed on the right eye. There were 64 (62.7%) males in the study sample.
Table 14 shows age-wise distribution of cataractous eyes. Maximum percentage (34.3%) of cataractous eyes for surgery were present in age group of 6-8 years with minimum percentage (11.0%) in age group of 10-12 years.
Table 14
| Age group | No. of cataractous eyes |
| 6-8 years | 62(34.3%) |
| 8-10 years | 53(29.3%) |
| 10-12 years | 20(11.0%) |
| 12-14years | 46(25.4%) |
| Total | 181 |
Seventy-eight percent of the eyes were blind at presentation [UCVA of light perception (LP) to <3/60]. Preoperatively, UCVA ranged from 6/18 to LP.
IOL was implanted in all the eyes.
Approximately 96.7% of the eyes presented for postoperative evaluation at one week, 69.6% at 4 weeks postoperatively and 47.5% at 6 month postoperatively. Patients were more likely to present at 1 week postoperatively (P = 0.000).
Table 15 showing post-operative visual acuity at 1st week, 4th week and at 6th month.
One hundred and forty three eyes (78.8%) were blind preoperatively. At 1 week postoperatively 20/175 (11.4%) eyes remained blind and 9/126 (7.1%) remained blind at 4 weeks. About 78.0%, 71.4% and 66.4% of the eyes had moderate vision i.e. between <6/18 and 3/60 at one week, 4 weeks and 6 month postoperatively, respectively. The proportion of eyes with this vision preoperatively was 11.8%.
Table 15
| V.A category | No of eyes (%) | |||
| Pre‑op | 1st week | 4th week | 6th month | |
| 6/6-6/18 | 17 (9.4%) | 19 (10.9%) | 27 (21.4%) | 21 (24.4%) |
| <6/18-6/60 | 4 (2.4%) | 72 (41.1%) | 62(49.2%) | 38 (44.2%) |
| 6/60-3/60 | 17 (9.4%) | 64 (36.9%) | 28(22.2%) | 19 (22.2%) |
| <3/60-PL | 143 (78.8%) | 20 (11.4%) | 9 (7.1%) | 8 (9.3%) |
| Total | 181 | 175 | 126 | 86 |
Figure 4: Visual assessment following cataract surgery
Outcome of strabismus surgery
Total of 240 children were operated out of which, 128 (53.3%) were esotropic and 112 (46.7%) exotropic.
The male to female ratio was 2:1. The pre- operative mean esotropia with standard deviation was 48.2±14.8 pd, with a range of 22 to 114 pd. The pre-operative mean exotropia was 57.8±14.2 pd, with a range of 25 to 90 pd. In 93.47% of the subjects, the ocular deviation after surgery reduced significantly (p=less than 0.00). After the strabismus surgery, orthophoria was achieved in 219 (91.3%) subjects, and with excellent cosmetics. After one month of surgery, gross binocular single vision was attained in 39.3% of the exotropes and in 17.9% of the esotropes. Only 30 % of the parents were aware about the strabismus and the treatment modalities. Nearly 90% of the parents were satisfied with the cosmetic outcome.
Surgical and functional outcome of congenital ptosis repair
A total of 20 patients underwent surgical ptosis repair, of whom 12 (60%) had unilateral and 8 (40%) had bilateral ptosis. The surgeries were levator resection 12 (60%), frontalis suspension 7 (35%), and Fasanella-Servat 1 (5%). Good functional and cosmetic outcomes were achieved in 19 (95%) patients, with unilateral cases showing more postoperative asymmetry. There were no significant differences in visual acuity, spherical equivalent, or mean cylinder at 90° between the ptotic eyes before and after surgery.
Discussion
In order to develop control programs to prevent childhood ocular morbidity in the country, it is necessary to identify important avoidable causes of severe visual impairment and blindness, and monitor changing patterns from time to time. The study findings of major causes of blindness in children would be useful for the District Blindness Control Society (DBCS) in planning for control of blindness in children in the area of the studied population.
There is a paucity of data available on ocular morbidity in children in India. Previously, various population- based epidemiological studies have reported the prevalence of childhood blindness from India; 0.65/1000 (95% confidence interval (CI): 0.15–1.15/1000) in children aged 0–15 years in urban and rural Andhra Pradesh (AP);61.25/ 1000 in children aged 5–15 years in rural Andhra Pradesh;7 and 0.53/1000 in children aged 5–15 years in Delhi.8
This present study shows the high prevalence of overall ocular morbidity (31.6%) and refractive errors (32.6%) among high school students in six districts of Rajasthan and highlights the urgent need to implement at school level health facility-based, cost-effective strategies, and appropriate eye care programs targeting school children to reduce the burden of visual impairment among the younger population.
The prevalence of ocular morbidity of 31.6% among school children of age 6-14 years in present study is similar to a study conducted in Delhi, where prevalence was reported to be 34.04% in the 5-14 years age group.9
However, another study showed higher prevalence of ocular morbidity in Rajasthan 71.7% in 4-16 years, 10 and in northern states like Haryana 58.8% in 4-18 years, 11 and also in Hyderabad in South India 43.5% in 3-16 years.12 It was because of the higher prevalence of trachoma and conjunctivitis found in these two northern states and of refractive errors found in South India.
Lower prevalence (15%) of ocular morbidity has been reported from Kolkata, West India among school children of 5-13 years, because of lower prevalence of refractive errors (2%) and smaller age group covered in that study.13
Review of international studies revealed lower prevalence of 15.6% of ocular morbidity in children aged 7-19 years in rural area of Tanzania, Africa.14 International differences in prevalence may also be explained by racial and ethnic variations, partly due to different lifestyles and living conditions in addition to different methodologies used.
Refractive errors are the leading cause of visual impairment in school-going and school-aged children reported in India and other developing countries.7,8,12,15,16,17,18,19 Globally, a huge burden of uncorrected/ unaided refractive errors has been reported in multiple surveys conducted among school-aged children in both Asiatic and other nations. (India: 2.63- 7.4%,7,8,12,16,17 Nepal:8.1%,18Pakistan:8.9%,19 Malaysia:17.1%,20 Iran: 3.8%,21 South Africa:1.4%,19 Brazil: 4.82%,22 Australia: 10.4%,23 Chile: 15.8%,24).
Present study shows the prevalence of refractive error is 32.6% which is comparable to the study done in South India where higher (32%) prevalence rate of refractive errors among school children of age 3-18 years was observed, because of higher case detection rate in that study by an optometrist.12 The overall incidence of refractive error has been reported to vary between 21% and 25% of patients attending eye outpatient departments in India.25 Similar prevalence of refractive errors has been observed among children of 12-17 years in Ahmedabad city.26
However, low prevalence of refractive errors of 2% has been reported from Eastern India by Datta et al., among primary school children of 5-13 years, which could not be explained.13
Jaya Biswas, Indranil Saha, Debabrata Das, Sabyasachi Bandyopadhyay, Biswarup Ray, Gautam Biswas conducted a cross-sectional observational study among 714 children of age group 5-15years attending Ophthalmology department at a tertiary eye care center in Kolkata, West Bengal and found the prevalence of congenital cataract to be 2.24% which is lower than the present study 5.8%, may be due to smaller sample size. But the prevalence of ptosis in the present study (0.6%) is comparable to that of ptosis prevalence (0.8%) in this study.27
Present study shows ocular morbidity more in the older,12-14 years of age group children, which is comparable to the above study, this may be because of higher prevalence of refractive errors among older children due to better detection of visual problem by them, suggesting lack of awareness among parents to detect them earlier.27
Strabismus affects between 2 to 5 percent of preschool population and is an important cause of visual and psychological disability.28
Prevalence of squint as reported by Pratap et al., of 2.8% of primary squint and that of paralytic squint as 0.42%, is lower than the results of the present study (5.6%). 29 However, in other studies higher (7.4% in 5-15 years) and lower (0.2-0.6% in 4-18 years) prevalence of squint has been reported from Haryana, Rajasthan, West Bengal and Delhi.10,11,13,17 which is comparable to present study. Studies done abroad also revealed lower prevalence of squint (0.5%) by Wedner et al., among children of 7-19 years in Tanzania, Africa.14
Vitamin A deficiency up to an extent of 5.4-9% in 4 to 16 years has been reported from Rajasthan and Kolkata respectively as compared to 8.3% in the present study.10, 13 This can be explained by lower socioeconomic status associated with unhealthy dietary pattern of children in those studies. Prevalence of vitamin A deficiency is almost equal in all the age group children in the present study. Internationally, Wedner et al., reported the prevalence of night blindness as 5.3% and bitots spots as 0.6% among school children of age 7-19 years in Tanzania.14 Since their study was done in the rural area, where children belonged to low socioeconomic status and had poor nutritional status, prevalence of vitamin A deficiency was high.
Prevalence of ocular diseases in the present study was more among boys (35.9%) than girls (27.0%). However, Khurana et al., reported higher prevalence in females (73.5%) as compared to males (49.4%) in Haryana.11 In their study, prevalence of infectious diseases like trachoma, conjunctivitis and blepharitis was high among females because of increased use of common ocular cosmetic material. Prevalence of vitamin A deficiency was found to be more among boys (3.3%) as compared to girls (1.9%) in the present study contrary to the results of other studies.10,13 This difference was more appreciable with prevalence of night blindness. However, being subjective, the symptom of night blindness cannot be relied upon completely.
In the present study, 181 eyes underwent IOL surgery, approximately 96.7% of the eyes presented for postoperative evaluation at one week, 69.6% at 4 weeks postoperatively and 47.5% at 6 month postoperatively. Patients were more likely to present at 1 week postoperatively (P = 0.000). About 78.0%, 71.4% and 66.4% of the eyes had moderate vision i.e. between <6/18 and 3/60 at one week, 4 weeks and 6 month postoperatively, respectively. While at first presentation in a study done in eastern Nepal and northern India30, 62.3% of the children were blind (<3/60 in the better eye). After more than 1 year, 53.5% had a normal visual status (range: 6/6 to 6/18). The followup rate was good upto 4th week but was low at 6th month which limited the ability to refract all patients and to treat all patients with amblyopia or low vision.
In the present study, prevalence of amblyopia was 1% ( out of 16168 children screened) which was lesser than the study done in Diyarbakir,Turkey31 where amblyopia was detected in 2.6% of all children screened, it might be because of starting of school screening camps which results in early detection of amblyogenic factors. Anisometropia was the main cause of amblyopia in the present study.
In the present study, after the strabismus surgery, orthophoria was achieved in 219 (91.3%) subjects, and with excellent cosmetics. After surgery, gross binocular single vision was attained in 39.3% of the exotropes and in 17.9% of the esotropes. Only 30 % of the parents were aware about the strabismus and the treatment modalities. Nearly 90% of the parents were satisfied with the cosmetic outcome. Horizontal and bilateral strabismus has good surgical outcome with improved cosmetic acceptance.
In the present study, congenital ptosis repair yields good functional and cosmetic outcome. Congenital unilateral ptosis was not associated with any differences in anisometropia or astigmatism between the ptotic and sound eye.
Conclusion
This cross-sectional study was conducted at different primary and secondary schools at six districts of Rajasthan under ‘Sarva Siksha Abhiyaan’ project and Pediatric ocular surgery was done at base hospital, Global hospital institute of Ophthalmology [GHIO].
A total of 16800 children (Boys 8344 and girls 7824) of age 6-14 years were enrolled for the study done over a period of one year.
It was aimed to determine the role of school screening camps and role of pediatric ocular surgery in sight restoration of children under guidelines of VISION 2020.
Through this study we came to the following conclusions:
- Overall prevalence of ocular morbidity among school children of age 6-14 years was 31.6% ( in boys 35.9% and girls 27.0%).
- Overall prevalence of ocular morbidity was highest (40.9%) among 12-14 years age group.
- Refractive errors 32.6% constitute the major cause of ocular morbidity in all the age group.
- Prevalence of amblyopia was 1%.
- Anisometropia 65.9% was the main cause of amblyopia.
- At 6th month of follow-up, after prescription of glasses and patching there was improvement in visual acuity with maximum percentage 45.5% of children having vision between 6/6-6/12 with a shift in percentage of amblyopic eyes towards improved visual acuity.
- Maximum percentage 34.3% of cataractous eyes for surgery were present in age group of 6-8 years. After cataract surgery and IOL implantation about 78.0%, 4% and 66.4% of the eyes had moderate vision i.e. between <6/18 and 3/60 at one week, 4 weeks and 6 month postoperatively, respectively.
- Out of 240 children operated for strabismus surgery, orthophoria was achieved in 91.3% subjects with gross binocular single vision was attained in 39.3% of the exotropes and in 17.9% of the esotropes.
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