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RANGACHARI SESSION VIDEO

Dr. Parikshit Gogate, Dr. Akshay Badakere, Dr. Rohit Chandramohan Khanna

Abstract

OBJECTIVE: To study the causes of severe visual impairment and blindness in students attending schools for the blind and to identify those whose vision could be improved by optical aids. On dispensing such aids, to study the improvement in function.

METHODS: Students in special schools for the blind underwent a comprehensive ophthalmic examination by a team of 4 ophthalmologists and 4 optometrists. World Health Organization-Prevention of Blindness forms were used to record history and examination details. Spectacles and low vision aids (LVA) were dispensed to those whose vision could be improved. The L.V.Prasad Vision Function Questionnaire (LVP-VFQ)was used to compare vision function before and after the intervention.

RESULTS: The study group consisted of 428 students from four schools for the blind, aged 4-36 years, of which 213 (49.5%) weregirls. The causes of blindness in370 children (<18 years) with vision <6/60were whole globe involvementin 31.6% students(This included anophthalmos (12.7%) andmicrophthalmos(16.4%)), nystagmus(7.8%), optic atrophy (5.9%), retinal causes (11.3%), phthisis bulbi (6.4%) and corneal scarring in 10.8% students.54 (12.6%) were dispensed spectacles and 41 (9.57%) LVA. There was a statistically significant difference in 7 of 21 questions (P<0.001) of LVP-VFQ.

CONCLUSION: Significant proportion of students in schools for the blind can be helped to improving vision function using optical aids. Students in schools for the blind need regular ocular examination and ophthalmic care.

Introduction

Causes of blindness and severe visual impairment have changed over past decades. [1][2][3][4] Blind children are usually educated in special schools for the blind. Children from this school for blind are considered completely blind, unable to see anything at all and deserving only for rehabilitation and aid. They are taught Braille, a touch-feel based language. But knowledge and literature in Braille is limited, that too mostly in European languages. The literature in Hindi, Marathi and other Indian languages in Braille is meager.

But studies from 34 schools for the blind in Maharashtra from 2002 to 2004, 24 schools for the blind in Karnataka and across four North Eastern Indian States showed that around 25-30% of legally blind children had some residual vision which can be utilized.[5][6][7] Another studyfrom Pune, India[4]had showed that giving spectacles and low vision aids to children could help them read print[8]. Seeing print and learning a written language improves the chances of getting on in the world – to learn better in schools, write exams, get degrees, to recognize and count money, do office jobs and even start and run a business.

While numerous studies from India, Middle-East, Asian and African countries have shown that many children in school for the blind have residual vision[5] [6] [7] [8] [9] [10] [11] [12]. Some even have treatable causes and blindness. But there are few publications on how these visually impaired children were helped[8] [10]. And literatureresearch showed that there were none about how much students improved their vision function.

This study aimed to find the causes of blindness in students attending schools for the blind, identify those with residual useful vision, treat them with optical aids and compare their vision function after and before dispensing such devices or aids.

A blind child is not just an individual affected but it affects the entire family and the community. There is a lot of opportunity not just in seeing and learning from the world but also a potential loss of educational, personal, social and economic advancement.

Methods

We have chosen all the fourschools for the blind in Pune city and district. They were chosen as they have children who are certified as blind and visually impaired in one place.

All the children have been examined in detail by a team of four doctors and four optometrists over two weeks.  Each child was examined using a pen torch, a hand-held slit lamp, direct & indirect ophthalmoscopy (if possible), I-kare tonometerand visual acuity examination by Landolt C chart, if vision was >1/60.  They were dispensed spectacles, magnifiers and telescopes for both near and distance vision aid. The near vision devices wouldhelp the children to read, write answer mobiles, make calls, thread a needle, clean vice, identify coins and look at small paintings. The distance devices would help then cross roads, identify bus numbers, road signs people from same distance and more easily and safety. World Health Organization-Prevention of Blindness forms were used to record history and examination details. [13]

The students were againre-visited and re-examined to observe what difference the intervention had made to their vision function after 6 months. Few students who were having potential to utilize their residual vision among them were given spectacles and low vision aids along with required training and advices. They were re-evaluated after six months of time period. Their functional vision and were assessed through a longitudinal study process.

The students were properly trained on how to use those devices. By asking them the L V Prasad eye institute Functional vision questionnaire, a base line idea about their functional vision were made. [14] After 6 months, the same questionnaire was asked to them by trained optometrists. On the basis of their personal realizations and feelings, how they rate (No difficulty, little difficulty, Moderate difficulty, Tough and Impossible), their performance, the difference between their functional vision performance prior to using low vision aids and after using low vision aids.

Screening of blind school children for causes of low vision:

  1. A detailed history including age of onset, incidence of family history, which family member is similarly affected history of Consanguinity, history of previously done treatments.
  2. Vision was taken separately for both the eyes either with habitual correction or unaided. ‘Snellen’s Distance Acuity charts’ were used from three-meter distance and vision was documented as per the code described in work up sheet
  3. Gross functional Vision was estimated by asking the students about their ability on walking alone, face reorganization, print reorganization and using residual vision in daily life activity with both eyes open.
  4. Visual field was tested very roughly in few students monocular with simple confrontation tests. The main binder for performing this test was their habitual fixation pattern. They won’t fix their head while performing visual field test.
  5. Then anterior and posterior (dilated) segment examination was done. Causes of low vision were derived from the under lying pathology.
  6. A general systemic association was also considered while examining a student.
  7. All these findings were used to plan the future steps like surgical intervention or providing optical correction and low vision aids and predict prognosis rate after intervention or academic consequences as well as.

Assessment of Vision Function:

  1. The first step of this portion was reassessing the students having potential to improve their visual status with optical correction.
  2. Through refraction was done. Uni-ocular as well as binocular vision was taken with the correcting lens on the trial frame.
  3. The selection of the students for low vision trail was a multi factorial consideration. Ability to use the residual vision, daily life activities, need, enthusiasm and ability to handle and take care of the device properly were the few important factors.
  4. (2.75X and 4X) Galilean Telescopes for distance whereas Hand Held LED/Non-LED Magnifier, Dome Magnifier, Spectacle Magnifier, Bar Magnifier were used for near trail.
  5. Device which is providing optimal visual performance with suitable posture was selected to prescribe. After assessing their vision with those devices both at near and distance as well.
  6. The students who would be received Low vision aids (either of near or distance or for the both) were verbally asked L V Prasad Eye Institute Functional vision questionnaire containing 21 questions. A base line idea about their functional vision was made by how they rate their ability to perform a particular task.
  7. Along with the optometrist a bilingual (Marathi and English) person was always there with a questionnaire in Marathi (translated and back validated) to help the students to understand the questions or specifically what were they being asked.
  8. Then the spectacles and Low vision aids were distributed. Students were thoroughly given training and advices on how to use those devices.
  9. Using non-optical devices like cap, umbrella etc. was also encouraged.
  10. After 6 months of giving those devices a follow up was made.
  11. Again that questionnaire was asked to every individual student.
  12. Pre and post rating then compared and analyzed by SPSS (version). P value of less than (0.001) was taken as significant.

Results

A total of 428 children enrolled in four schools for the blind underwent comprehensive eye examination in 2015-16 with a follow up after six months. 215 (50.2%) were boys and 213(49.8%) were girls. Their ages ranged from 4 to 36years.  While calculating causes of blindness data of age group between 4 to 18 years of was taken in to consideration Visual acuity was assessed separately for each eye.  For the right eye, 159 (37.1%) had no perception of light (PL) while 222 (51.9%) had vision <3/60 to PL and/or projection of rays (PR) while 15 (3.5%) had visual acuity of 6/18 – 6/60.6/60 -3/60 was recorded in 37(8.6%) of children, 6/18-6/6 in 1(0.2%). For the left eye 153 (35.7%) had no PL while 221(51.6%) had vision <3/60 to PLPR.6/18-6/60 was recorded in 15(3.5%) students and6/60 -3/60 in 37(8.6%) students.6/6-6/18 was observed in 1 student (0.2%).

135 (31.5%) hadbeen blind since birth, 184 (43.0 %) became blind in the first year of life while 82 (19.2%) became blind after infancy. 95 (22.2%) had another blind member in the immediate family, while 29 (6.7%) reported a consanguineous marriage of their parents. Out of 428students, 219 (51.1%) reported they saw enough to walk around, 183 (42.7%) reported they could recognize faces and 149 (34.8%) reported could read print.

Additional disability was not noted in 405(94.62%) children.Only 4(0.9%) had hearing loss and learning disabilitywasseen in 5(1.2%) students.Out of all 428 students, 370 were bilaterally blind, with vision <6/60, aged <18 yrs. The causes of blindness in these 370 children were congenital whole globe anomalies 117(31.6%) (This included anophthalmos in 47, 12.7%; microphthalmos 61, 16.4%; both in 9(2.4%) students), nystagmus in 29 (7.8%), optic atrophy in 22(5.9%), retinal causes in 42(11.3%), phthisis bulbi in 24(6.4%) and corneal scarring in 40(10.8%) students.Cataract was responsible for blindness in 18(4.86%) of students.ROP is noted as cause of blindness in 4(1.1%)students.

There were 15(3.5%) students who had undergone cataract surgery but nonetheless had poor vision after the surgery in them due to posterior segment pathology (high myopia) in 2(13.3%)and /or amblyopia in 9 (60%). Two(13.3%) had nystagmus, one had corneal scar (6.6%), one (6.6%) had anterior staphyloma. While 5(18%) had very high astigmatism which is the cause of visual impairment in these students.

Seven (1.8%) children were recommended a change of schooling while 6(3.7%) children were recommended cataract surgery.9 (2.10 %)were recommended corneal transplant. 54 out of 428 children were dispensed spectacles and/or low vision aids, aged 7-23 years out of which 27 (50%) were girls. Only spectacles were given to 15 students, low vision aids for distance to 11 students (8 of whom also received spectacles), low vision aids for near to 17 students (of whom 13 also received spectacles) and low vision aids for distance and near to 11 students (6 of whom also received spectacles). The spectacles given to students had refractive power ranging +10.0 to -22.0 D sph and from -7.0 to +1.75 cyl. out of which 23/42(54.7%) attained N6-N12 acuity. After dispensing low vision aids, 10 students could identify font of N6, 5 students of N8, 1 of N10, 7 of N12, 2 of N18 and 1 on N36, 26 in all could identify letters or numbers. With spectacles and low vision aids, 1 improved to 6/6, 3 to 6/9, 2 to 6/12, 6 to 6/18, 5 to 6/24, 5 to 6/36 and 2 to 6/60. Three more students had their vision improved from 3/60 to <6/60.

The selection of the students for low vision trail was a multi factorial consideration. Ability to use the residual vision, daily life activities, need, enthusiasm and ability to handle and take care of the device properly were the few important factors.

The distribution of the devices were as follows:For distance vision, 9children(16.6%) were given2.75Xg telescopeand 12(22.22%) were given4xGtelescope.For near vision, 2.5Xdome magnifier was given to 8(15%)students, 4x stand magnifier is given to 1(1.85%), a hand magnifier 10x in 1(1.85%) case while a 3xhand magnifier with LED was given to 4students (7.40%).

The students who would be received spectacles and/or low vision aids (either of near or distance or for the both) were verbally asked L V Prasad Eye Institute Functional Vision Questionnaire[1] containing 21 questions by the same team of optometrists. A base line data about their functional vision was recorded before they were dispensed spectacles and LVAs.

After six months of dispensing all 54 students were made to fill up the questionnaire. Their reply was analyzed significant p – value readings are observed.Pre and post rating then compared and analyzed by SPSS (version). P value of <0.01 was taken as significant. The details are given in Table 1.

 

Table 1

  Pre-intervention Post-intervention p-value
Min Max Median Min Max Median
Q1 Do you have any difficulty in making out whether the person you are seeing across the read is a boy or a girl, during the day? 0 4 1 0 1 0 < 0.001
Q2 Do you have any difficulty in seeing whether somebody is calling you by waving his or her hand from across the road? 0 3 0.5 0 1 0 < 0.001
Q3 Do you have difficulty in walking alone in the corridor at school without bumping into objects or people? 0 3 0 0 0 0 0.006
Q4 Do you have any difficulty in walking home at night (from tuition or a friend’s house) without assistance when there are streetlights? 0 3 2 0 3 1 < 0.001
Q5 Do you have any difficulty in copying from the blackboard while sitting on the first bench in your class? 1 4 2 0 4 1 0.001
Q6 Do you have difficulty in reading the bus numbers? 1 4 2 0 4 1 < 0.001
Q7 Do you have any difficulty in reading the other details on the bus (such as its destination)? 1 4 3 0 4 1 < 0.001
Q8 Do you have any difficulty in reading your textbooks at an arm’s length? 0 4 2 0 4 1 < 0.001
Q9 Do you have any difficulty in writing along a straight-line? 0 3 1 0 2 0 < 0.001
Q10 Do you have any difficulty in finding the next line while reading when you take a break and then resume reading? 0 2 1 0 4 0 0.006
Q11 Do you have any difficulty in locating dropped objects (pen, pencil, and eraser) within the classroom? 0 3 0 0 3 0 0.016
Q12 Do you have any difficulty in threading a needle? 0 4 2.5 0 4 1 0.026
Q13 How much difficulty do you have indistinguishing between 1rupee and 2 rupee coins (without touching)? 0 4 0 0 1 0 0.002
Q14 Do you have difficulty in climbing up or down stairs? 0 3 0 0 2 0 0.041
Q15 Do you have difficulty in lacing your shoes? 0 4 0 0 1 0 0.010
Q16 Do have difficulty in locating a ball while playing in the daylight? 0 4 1 0 3 1 < 0.001
Q17 Do you have difficulty in applying paste on your toothbrush? 0 2 0 0 0 0 0.034
Q18 Do you have difficulty in locating food on your plate while eating? 0 2 0 0 0 0 0.011
Q19 Do you difficulty in identifying colors (e.g., while coloring)? 0 4 0 0 3 0 0.006
Q20 Do you have difficulty watching television properly 0 3 0 0 3 0 0.007
Q21 How do you think your vision is compared with that of your normal-sighted friend? 1 3 2 1 3 1 0.007

All of these students showed significant improvement in theirvision function for all the 21 questions, butthere was a significant difference was noted in following questions: Differentiating whether a person across the street was a boy or girl, if someone was waving across the road, difficulty of walking home at night, reading the bus number, reading other details on the bus, locating a ball while playing, writing in a straight line and reading the text book at an arm’s length.

Discussion

A large number of students in school for blind were congenitally blind due to abnormality of the globe. So many students had no perception of light. But some students could use their residual vision for functional purposes. Some of the students could see to walk around, recognize faces and prints. The purpose of the prescribing LVAs was to improve their residual vision for functional use. Regular examination of students for refraction, fundus and anterior segment with low vision assessment could result in significant improvement in vision function of the students. With improvement in visual functions, they can have a better and more integrated education, recognize numbers, perform simple mathematics, read regional languages and/or English, all of which would result in better opportunities, in work and social life. The students who were dispensed optical aids reported significant improvements in distant vision activities like recognizing far of things and near vision ones like writing in a straight line. There was no significant improvement for activities like walking down the corridor, applying toothpaste on the tooth brush or tying of shoelaces as the children would have adapted to and mastered these activities of daily living even without significant vision.

While numerous studies across the globe have reported students of schools for the blind having residual useful vision and recommending correction, we believe this is the first study to report the actual improvement in vision function after provision of low vision aids after 6 months follow-up. [8][10]

The earlier in life a special child was examined and dispensed low vison aids and spectacles, the greater would be the chances of their learning better and developing diverse set of skills.

Like results of some African and Asian studies, there were 12 students with operable congenital or developmental cataracts in the students of the schools for the blind.[9][15]There were 15 (3.5%) who had undergone cataract surgery but nonetheless that poor vision after the surgerydue to coexisting ocular morbidity. But 9 out of 15 (60%) had amblyopia. Thisagain underlined the fact that mere cataract surgery in blind children is not enough. A regular, active long-term follow-up with optical correction and anti-amblyopia treatment was needed otherwise the gains of a good surgical intervention would be nullified. [16]

Whole globe anomalies, anophthalmos and microphthalmos were the commonest causes of blindness in children, like the studies published from these schools for the blind earlier.[5][6][7][17][18]While their exact cause is a matter of conjecture, a genetic and environmental interaction has been proposed.[19][20]More research is needed in this important field, as these relatively common conditions can be so far managed only by rehabilitation and low vision aids. [8][10][21]

Retinopathy of prematurity, as a cause of blindness that was not observed in these schools 2002-2004 series and seen inonly one child in 2011-12 was now an established cause of blindness in children in school for the blind. Children blind with retinopathy of prematurity lose their vision in early infancy, but most children join a special school for blind when they are 5 to 8 years of age. Thus, there is a time lag of half a decade between such children losing their vision and being seen in special schools for the blind. But India’s burgeoning population, vast increase in neonatal care coverage, its uneven quality and relatively poor awareness and opportunities for early screening of neonates at risk make retinopathy of prematurity an avoidable and iatrogenic cause of childhood blindness that would need enormous effort and co-ordination between the numerous public, private and not for profit stake holders to eliminate retinopathy of prematurity as a cause of blindness in children. And to ensure that not many need special education in schools for the blind.

Most residential schools for the blind offer not just free schooling but also free lodging, boarding, food, books and other educational aids. The parents pay practically nothing as governments and philanthropists pick up the tab. This may be a vicarious incentive for many parents to keep the children in such special schools, even if they can see enough to attend normal schools. Also from parents’ viewpoint, such schools offer a modicum of safety, allow socializing with similar peers and take complete responsibility of the child. So while some stakeholders may not be enthusiastic about integrated education, all schools for the blind children should undergo a comprehensive eye examination that is repeated every other year and are prescribed and dispensed optical devices to maximize their limited visual potential and are taught to recognize and read print.

A limitation of our study was the outcome was assessed subjectively in the form of a questionnaire. There may have been a floor and ceiling effec

References

References

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