|Year : 2019 | Volume
| Issue : 2 | Page : 117-122
Impact of refractive error correction on mental and visual development in children with global developmental delay
KS Smitha1, VD Patil2, Mahesh D Kamate2, Madhav Prabhu3, Umesh Harakuni1, OP Rakshitha1
1 Department of Ophthalmology, J. N. Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
2 Department of Pediatrics, J. N. Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
3 Department of Medicine, J. N. Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
|Date of Web Publication||4-Jun-2019|
Dr. K S Smitha
Department of Ophthalmology, J. N. Medical College, KLE Academy of Higher Education and Research, Belagavi - 590 010, Karnataka
Source of Support: None, Conflict of Interest: None
PURPOSE: The purpose of the present study is to evaluate visual acuity and refractive status in children with global developmental delay (GDD) and to study the effect of early correction of refractive errors on vision and developmental quotient (DQ).
METHODS: In this case series data with pre–post design, 100 consecutive children from 1 to 5 years of age diagnosed with GDD attending the child development clinic and referred to ophthalmology were evaluated for ocular complaints, status of visual acuity, and type of refractive error. Glasses were prescribed on the basis of cycloplegic retinoscopy. Etiological diagnosis and DQ were documented. Follow-up was done after 6 months for visual acuity, DQ, and qualitative questionnaire administered for the caretaker. Statistical analysis was done using the Chi-square test.
RESULTS: Fifty-six children were <2.5 years of age and 44 children were >2.5 years. Severe GDD prevalence was more in children <2.5 years (43%) and mild GDD in >2.5 (50%). Of 47 who showed improvement in vision, 39 (71%) showed improvement in social behavior also, which was statistically significant. In children <2.5 years, more improvement in DQ was seen in the moderate intellectual disability group after refractive error correction. However, in the children of 2.5 years and above, more improvement was seen in the severe group. Overall, improvement in DQ in children from 1 to 5 years was statistically significant at 14%.
CONCLUSION: Harmful effects of sensory visual deprivation on the development and functioning can be dampened by a simple and cost-effective approach of spectacles therapy which makes a spectacular effect in the case of children with GDD.
Keywords: Developmental quotient, global developmental delay, refractive error
|How to cite this article:|
Smitha K S, Patil V D, Kamate MD, Prabhu M, Harakuni U, Rakshitha O P. Impact of refractive error correction on mental and visual development in children with global developmental delay. Indian J Health Sci Biomed Res 2019;12:117-22
|How to cite this URL:|
Smitha K S, Patil V D, Kamate MD, Prabhu M, Harakuni U, Rakshitha O P. Impact of refractive error correction on mental and visual development in children with global developmental delay. Indian J Health Sci Biomed Res [serial online] 2019 [cited 2020 Feb 29];12:117-22. Available from: http://www.ijournalhs.org/text.asp?2019/12/2/117/259641
| Introduction|| |
Global developmental delay (GDD) is a developmental disability in children <5 years of age and refers to a significant delay in at least two of the major developmental domains: gross/fine motor; speech/language; cognition; social and personal development; and activities of daily living. Generally, all domains are affected. A study done in 2005 focused on the outcomes or natural history of children diagnosed early in life with developmental delay, without any intervention, after a mean duration of 4 years and found that 75%–100% of the children remained below the mean scores compared to age-matched normative data. They found persistent poor performance at school age in both developmental and functional outcomes. GDD has a primary initiating factor of cerebral damage and secondary compounding factors such as associated visual or auditory defects. Visual impairments range from 13% to 50% and audiologic impairments of 18%. Visual impairments affect intellectual development and motor achievement by hampering neurological development., The American Association of Neurologists says that the diagnosis in their formative years leads to better outcome.
Johnson and Zabastudy found that of the various ocular manifestations, refractive error is the most common (20%–60%) and 80% of learning by children is through the visual information. The process of emmetropization involves or is guided by visual feedback mechanism. Thus, visual deprivation in infancy leads to retention or increase in refractive errors. Although intellectual disability (ID) is not treatable, visual impairments benefit from early intervention. Vision is central in early interaction and motor development. Intervention at this crucial age is important as the child is most receptive and hence should not be missed.
Intervention is aimed at improving the disturbed visual sensory input, to enhance child's neurological development through visual support and increase the educational gains and decrease dependence on social institutions, providing economic and social benefit.
Studies are lacking in the youngest age group with GDD, i.e., under 5 years with quantification of visual acuity and development quotient (DQ), before and after treatment. Thus, we aimed at correcting this important sensory input of vision at the young age of 1–5 years and evaluating its effect on visual and mental development and factors which are affecting it.
To study the effect of early correction of refractive errors in children of age 1–5 years with GDD on Vision and Developmental Quotient (DQ) and their determinants.
| Methods|| |
Children of age below 5 years attending the Child Development Clinic in Paediatric Department and diagnosed with GDD were taken for the study. The study comprised 100 consecutive GDD children attending tertiary care teaching hospital of North Karnataka during May 2014 to June 2017. Study design was pre-post. The data about perinatal history of children and consanguinity were collected from Medical Records. Children with refractive errors without other ocular anomalies were considered for the study. The expected cases of the improvable refractive error as per the literature were 15%–61%. Sample size was computed with 80% power and 15% minimum expected improvement, as 100.
The protocol was approved by the Ethics Committee, and as the kids are doubly vulnerable because of age and inability to process information, written informed consent was obtained from parents/legal guardians. Children with progressive neurodegenerative conditions, auditory, and other systemic abnormalities which could act as confounding factors were excluded. After screening 164 consecutive children from 1 to 5 years of age diagnosed with GDD, 120 were found to have refractive error. Complete ocular examination of the anterior segment and dilated fundoscopy was done to rule out any other ocular abnormalities. After exclusions, 114 fitting the eligibility criteria were enrolled. Final data analysis was done in 100 children excluding children noncompliant with glasses and who were lost to follow-up at the time of reassessment after 6 months.
GDD children of age 1–5 years were assessed on the following variables: visual acuity, refractive error, and DQ. Follow-up was done after 6 months for the same, along with a questionnaire for the caretaker. Compliance factor was defined as wearing of spectacles for a minimum of six waking hours.
- Vision assessed with preferential looking test using Teller acuity cards. The accuracy (test-retest reliability) of the acuity card test is one octave. A difference of one octave was significant as per the norms and considered as visual improvement. Assessments were made by two different observers with a break of few hours in between and had high interobserver agreement
- As the standard practice parameters are set for normal children, the cutoff points for refractive error were taken based on other studies of GDD.,
Glasses were prescribed based on these cutoffs on the basis of wet retinoscopy (with atropine to nullify accommodation):
- Myopia of more than −0.50 diopter (D)
- Hypermetropia of more than +1.00 D
- Astigmatism more than 1.00 D.
- DQ – under 2.5 years– DASII (Developmental Assessment Scales for Indian Infants)
Above 2.5 years – Pandey's Cognitive Development Test for Preschoolers (PCDTP).
ICD-10 – DQ is divided into grades according to the levels of severity.
- Mild ID: 50–70
- Moderate ID: 35–49
- Severe ID: 20–34
- Profound ID: <20.
(As the number of children having profound ID was small, it was incorporated in the severe ID group for the analysis). This testing was done by the Child Psychologist of the Child Development Center of Pediatric Neurology Department.
DQ improvement/deterioration was defined as the change in the grade of severity.
- The questionnaire had three groups of questions for gross motor, fine motor, and behavioral changes of study children. Questions were drawn from adaptive behavior scales which had previous validation.
Quantitative variables such as refractive error, visual acuity, and DQ were converted into interval scale for analysis. Data were in ordered scale; contingency tables were made for descriptive presentation. Chi-square test was used to study the impact of explanatory variables on visual acuity, DQ, and social behavior. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp., was used for data analysis.
| Results|| |
In this study, 56 children were <2.5 years of age and 44 children >2.5 years. Forty-five were girls and 55 were boys. In children <2.5 years, 43% were in the severe ID group, whereas 50% of children in the older group had mild ID, which was statistically significant (P < 0.001).
Of the 100 babies, 13 were preterm whereas 87 were term babies. About 50% of term children had improvement in vision compared to 23% in preterm, whereas 4 (30%) of preterm children showed deterioration in vision compared to 3 (3%) in term children.
On the evaluation of DQ by refractive error, in all the grades of DQ, the number of children having hyperopia was the highest [Table 1], P < 0.07]. Improvement in vision in myopes was 71.4% which was the highest although not statistically significant. Statistically significant improvement was seen in 69% of children with mild ID [Table 2], P < 0.003]. On comparing post by pre-DQ, statistically significant improvement in DQ in 14% of children from 1 to 5 years was noticed at [Table 3], P < 0.000].
| Discussion|| |
Most of the previous studies have a wide range of age. Hence, we have concentrated exclusively on children under 5 years having GDD with refractive errors, (the crucial period of brain development) intervention at this period makes the maximum impact.
The evaluation of DQ was by DASII in children <2.5 years and by PCDTP in >2.5 years. Hence, the evaluation for all variables was also done separately in these two age groups. In our study, 56 children were below 2.5 years of age and 44 children were at 2.5 years and above.
We found a significant distribution of DQ in both the groups:
- Severe ID children were more in children <2.5 years (43%)
- Children with mild ID were more in age group >2.5 years (50%).
Although equal distribution of children was seen in all three grades of ID, younger group had more of severe form and older group had more of the mild form. This could be explained on the basis that this was a hospital-based study and not community based as in other studies, as parents of children with severe and profound ID, who usually have other associated disabilities too, enthusiastically pursuing treatment initially lose hope leading to reduced hospital visits.
In this study, cerebral palsy was the most common cause, found in 40 children followed by syndromic causes such as Down syndrome, Seckel syndrome, and miscellaneous in 12 children. In 48% cases, cause could not be identified in spite of rigorous workup. No relationship was found between the etiology of chronic venous insufficiency (CVI) and timing of the insult on the improvement of visual function.
Gestational period and birth weight
Kozeis et al. 2015 study found that prematurity is not an added risk for refractive error development. Similarly, refractive error distribution was not significant in preterm and term babies, but there was significant correlation in response to the refractive correction. Term children improved more than preterm. This stresses the need for rigorous management in preterm children.
Refractive error by developmental quotient
McQuaid and Arvidsson report that refractive errors are four times higher than in neurologically normal age-matched children and the prevalence of hyperopia is more. Moreover, refractive errors increase significantly with severity of ID. Distribution of hyperopia was similar in our study.,,
The distribution in the majority of children was low-to-moderate hyperopia. However, there are children with moderate-to-high myopia, thus increasing the range of refractive errors (−7 D to +5.5 D). Although hyperopes were more in number, improvement in vision seen was more in myopes at 15 (71.4%). Hyperopia in the age group of 1–4 years was associated with amblyopia. Although hyperopia is present in most of the children which could be normal to that age in normal children, we feel that in children with GDD, the fact that they are causing amblyopia, with the added delay, justifies the need for correction, unlike the children without delay.
Pigassou-Albouy studied a group of cerebral palsy which found strabismus in 50%, whereas in general population, it is 3%. Of 100 babies, 69 had orthophoria, 22 had esotropia, and 9 had exotropia. Nineteen (86.4%) children with esotropia had hyperopia. The high incidence could be attributed to the fact that they are done in specific populations, similar to an Aravind Hospital Study.
Social behavioral change
Of 47% children, who showed improvement in vision, 39 (71%) showed improvement in social behavior also, which was clinically and statistically significant, and it was not age related. Maximum improvement seen in behavior in the mild ID group (44% improved) was similar to pattern of improvement in vision and can be attributed to betterment of functional vision.
Improvement in vision in relation to improvement in developmental quotient
A study done in Pune on the improvement in scholastic activities concluded that 26.4% of children had their vision improved with refraction. A retrospective study by Watson done on CVI patients found that 49% improved in vision after correction after a mean duration of 6.5 years. In our study, 47% improved which was clinically and statistically significant [Table 4] and [Graph 1].
The improvement seen in vision was more in mild ID group (69%), followed by the moderate (46%) and least seen in severe ID (26%) children.
Even though maximum improvement in vision was seen in mild ID group, DQ largely remained same. This is contrary to what one would expect. However, deterioration was also very less compared to other groups. It was also seen that the amount of improvement was less in the moderate ID group than the severe group in the older age children stressing the Watson et al.'s theory. They concluded that the worse vision group improved better than the initially better vision group, as worse group had “more room for improvement” that leads to greater change. This explains the improvement seen in the severe ID group in our study.
Although visual growth occurs, neural plasticity comes down, and the scope of exponential improvement in DQ through intellectual development and motor achievement reduces, which explains the minimal DQ improvement in spite of maximum visual improvement in the mild ID group. Longer follow-up of up to 6 years in few other studies has also shown that severe ID group has more room for improvement, which was proved in our study, quantitatively.
Is this just an age effect...??
Bader and Woodruff study showed the improvement in the new glass group and in the youngest age group (0–6 years). They reviewed the effects qualitatively in behavior after 2 months and assumed that the improvement in ability to walk, grasp objects, balance, etc., was not due to maturation. They deduced that spectacle changes the spatial perceptions and results in improvement. In our study, the improvement seen on follow-up after 6 months is a short span and cannot be attributed to maturation. This was confirmed by our analysis of 20 children with GDD without refractive error after 6 months who showed no statistically significant difference/improvement in DQ, ruling out the age effect.
| Conclusion|| |
In both age groups, severe and moderate groups show better improvement in DQ than mild ID group. However, it is also seen that as age increases, the amount of improvement decreases. Thus, proving the fact that the earlier the intervention, greater the improvement in their DQ, as neural plasticity is better.
These results are useful in the diagnosis and clinical management by providing quantitative information about visual impairment. It is useful in alleviation of parental anxiety, assistance in early childhood intervention programs, and genetic counseling. In this view, implementing mandatory quantitative evaluation of visual acuity and refractive corrections in children with GDD would go a long way in the overall development of the child.
The multifaceted therapy in children with GDD is costly. Spectacles are simple, easily available, and cost-effective strategy. In the backdrop of increasing neurological cases in the Indian scenario, the cause of which is multifactorial such as poor parental care, consanguinity, and nutritional issues, this study stresses on the need for awareness among the treating pediatricians, ophthalmologists, and parents/caretakers regarding early ophthalmic care and the simple approach of prescribing glasses which make a spectacular effect in case of children with GDD.
Perinatal history was collected retrospectively, which could lead to minimal bias. Compliance in wearing glasses for full waking hours could not be achieved.
The age at which these tests would give optimal results should be addressed. Furthermore, the aspects of quality of life and social support by the family need to be addressed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]