Low vision is a leading cause of disability which requires aid in activities of daily living. Chronic, disabling, non-reversible vision impairment that cannot be corrected medically, surgically or with conventional refraction are collectively known as low vision[1].

The W H O defined low vision in 1992 as follows;

“A person with low vision is one who has an impairment of visual functioning even after treatment and/or standard refractive correction, and has a visual acuity of less than 6/18 to light perception or a visual field of less than 10 degrees from the point of fixation, but who uses or is potentially able to use, vision for planning and/or execution of a task.”

The primary role of vision rehabilitation for all such patients is to maximize functional independence, to maintain quality of life, and to help the patient adapt to the psychosocial aspects of vision loss[2-3].

Vision rehabilitation trains patients to use their residual vision or alternate compensatory techniques effectively and to make practical adaptations in their environment to facilitate activities of daily living, ensure safety, and maintain independence.

High myopia is one of the major causes of low vision and these children show much improvement and can utilize their functional vision with the help of low vision aids to improve Quality of life. High myopia is favourable for low vision correction because in most cases the onset is in childhood and the patient has always read in close range[4]. The issue of low vision in a child is more important in the sense that it not only restricts the orientation and mobility skills of the child, it affects psychological development of the child by restricting education, social and emotional development[5-6].

The WHO⁶ defines Quality of Life (QoL) as the ‘‘individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns.’’

AIMS AND OBJECTIVES

Our aim is to compare the post visual rehabilitation improvement in quality of life among the 2 subsets of myopic children who were prescribed optical versus non-optical vision aids.

To assess which measure has earlier and better outcome.

To find out the compliance after the visual rehabilitation with optical and non-optical low vision aids.

 To compare the pre and post low vision aids, Quality Of Life (LVQOL) by means of LVP-FVQ

The study was conducted in the department of ophthalmology, Index Medical College, with the purpose to compare improvement in LVQOL in children having low vision due to myopia with optical versus non optical aids.

STUDY DESIGN- prospective randomized and comparative study.

STUDY PERIOD- may 2023 to august 2024

STUDY POPULATION-All children with low vision due to myopia coming to our OPD were randomly divided into 2 groups.

Group 1 - prescribed optical aids for distant and near work.

Group 2 -prescribed non optical modification such as relative distance enlargement.

Patient inclusion criteria:

Myopic children of 5-18 yrs of age group.

Visual acuity ≤6/18 (snellen’s chart) or ≥0.50 (in logMAR chart) in the better eye.

Central 20 degree visual defect.

Patient exclusion criteria:

PL denied patients.

Patient with >1 contributing disease (for e.g. any posterior chamber abnormalities)

Patients with central corneal opacity.

Patient in whom associated co-morbidities limit the use of a visual aid.

Pre and post prescription vision related quality of life was judged with LVP-FVQ Questionnaire.

A thorough evaluation of the patient regarding his present visual status, visual function, task targets, school related and personal needs concerned with vision was done.

Factors like degree of visual impairment, goals, objectives and requirement, patient motivation had also been given due consideration. The format which was used to collect information about the patient is attached.

Primary outcome measure: 

Post rehabilitation comparison of the improvement in the 2 subsets of children.

Secondary outcome measure:

In which subset rehabilitation is earlier and better.

Compliance with the prescribed aid was also judged in the follow up visits.

Follow up period:

Follow up after 1 month of prescribing LVA and subsequently after 3 months

The minimum age was 10 years and maximum was 18 years with a mean of 13.65 yrs (±2.39). Higher no. of male (70%) patients compared to female patients (30%) presented to our LVA clinic.35% of our patients belong to primary school, 40% to middle school and 25% belongs to high school. Family history of myopia was present in 40% of the patients. None of the patient previously used or prescribed low vision aids.

Mean presenting BCVA in better eye was 1.05 log MAR. Majority (55%) of patients had BCVA lying in Category-1(ICD 10) (0.5 log MAR-0.9 log MAR).

In group 1 (optical aids) the mean BCVA for distance in right eye was 0.92 logMAR (SD=0.187) and in left eye was 0.78 (SD=0.26).

In group 2 (non optical aids) the mean BCVA for distance in right eye was 0.92 (SD=0.10) and in left eye was 0.92 (SD=0.13).

There was statistically no significant difference between the mean BCVA for distance of the 2 groups.

Mean BCVA for near in better eye was 1.48 logMAR.

In group 1 (optical aids) the mean BCVA for near in right eye was 1.92 logMAR (SD=0.7) and in left eye was 1.43 (SD=0.66).

In group 2 (non optical aids) the mean BCVA for distance in right eye was 1.62 (SD=0.43) and in left eye was 1.58 (SD=0.40).

There was statistically no significant difference between the mean BCVA for near of the 2 groups.

In group 1 (optical aids), the mean spherical equivalent of the right eye was -8.50 (SD=2.99) and in left eye was -8.30 (SD=3.04).

In group 2 (non optical aids), the mean spherical equivalent of the right eye was -7.60 (SD=1.26) and in left eye was -7.70 (SD=1.25).

There was statistically no significant difference between the mean spherical equivalent of the 2 groups.

50 % of patients were prescribed with optical aids and rest 50% were prescribed non optical aids.

Among optical aids for distance 4x telescope was prescribed to 50% patients and for near dome magnifier to 20% and hand-held magnifier to 10% patients.

Among non optical aids for distance arrangement of sitting close to blackboard and lighting advice was given to 50% of patients while for near advice of reading at a distance <25 cm, with overhead illumination lamp and slanting table was prescribed to 45% patients.

At 1 month the quality of life improved with the use of both optical and non optical aids and the improvement was statistically significant in both the groups

At 3 months the quality of life improved with the use of both optical and non optical aid sand the improvement was statistically significant in both the groups.

The change in quality of life (assessed with the score) at 1 month from initial QOL was higher in Group 1 (Optical aids) than in Group 2 (non optical aids) and this difference was found to be statistically significant. Thus the improvement is earlier in group 1 i.e, with optical aids.

Similarly the change in QOL at 3 month from initial QOL was higher in Group 1 (Optical aids ) than in Group 2 (non optical aids) and this difference was found to be statistically significant. Thus the optical aids have better outcome than non optical aids.

65% of patients using their low vision aids regularly, while 15% do not use them regularly and 20% lost to follow up.

This study represents data of 20 patients attending our LVA clinic between may 2023 to august 2024, who confirmed to the inclusion criteria as laid down earlier.

Low vision examination is a tedious procedure which requires longer time, co-operation by the patient and patience on the part of the examiner.

Several questionnaires have been developed for assessment of quality of life. But most of them are useful for adults. There is some recent development of questionnaires targeting pediatric population. These are the Children’s Visual Function Questionnaire (CVFQ)[7], the Impact of Visual Impairement on Children (IVI_C)[8] and LV Prasad Functional Vision Questionnaire (LVP-FVQ). In present study we used LVP-FVQ since its been developed in India, so the questions are according to our culture.

The age range in our study is from 10 to 18 years while in the study by Gothwal et al[9] , in which LVP FVQ was developed, the age range from 8 to 18 years. In another study using LVP-FVQ by Boyumi et al[10] the age group ranged from 5- 18 years. The questionnaire used in their study was also LVP-FVQ. In another study using LVP-FVQ by Ganesh et al[11], the age ranged from 6- 16 years.

In our study, the group with optical low vision aids, for distant vision 100% of the children prescribed telescope and for near vision 40% improved with dome magnifier while 20 % with hand held magnifier. Improvement in VA was seen in all patients. In a study by SA Khan et al hand-held distance telescope (45 patients) and hand-held magnifier (9 patients) were prescribed, and both the optical aids results in improved VA of the patients.

In another study ‘low vision correction in myopia’ by Fonda et al, found that dome magnifier (visolett) in addition to a spectacle magnifier provides double magnification and is quite acceptable.

Corn et al (2002) measured reading rates and comprehension for children before and after issue of LVAs (optical magnifiers) to 130 children and showed a significant improvement in silent reading speed (effect size 1.29) and comprehension (but, interestingly, not in oral reading speed or comprehension) [12].

In a similar study by Nilsson et al (1986), targeted at outcomes in patients with macular degeneration receiving optical and educational low vision intervention, he followed 120 patients for a mean of 5 years (range 3-8 years) [13]. After provision of LVAs, patients received an initial series of weekly training sessions (mean 3 SD 2.8 x 1 hour visits) and the VA improved both for near and distance.

Goodrich et al (2006) showed a marked improvement in reading speed after a comprehensive inpatient reading rehabilitation programme (prescription of best optical/electronic device with 10 x 45 minute training sessions)[14]. There was an improvement in self-report measures of satisfaction with reading and difficulty reading.

Gajdosova E et al in a study “Improvement in the outcome of visual impairment using low vision aids in children” retrospectively reviewed the notes of 113 patients (pts.) with VI.171 LVAs were prescribed to 74 patients (65%): 76 (44.4%) were magnifiers, 21 (12.3%) were hyperoculars or high adds, 65 (38%) were telescopes and 9 (5.5%) telescope extensions. An average of 1.5 devices was prescribed for each patient. Every patient who was prescribed an LVA had subjective and objective improvement of their visual function and functional vision[15].

In our study, the group with non optical aids, relative distance enlargement such sitting closer to blackboard for distant and reading at a distance<25 cm for near (10 patients), slanting table  (9 patients) and lighting advice ( 10 patients) were prescribed. SA Khan et al in his study prescribed reading lamps, light control devices and brimmed hat and found that though it was not possible to measure the improvement objectively, non-optical aids enhanced subjectively the use of vision in the patients[16].

Wolffsohn and Cochrane (2000) evaluated a group of individuals undergoing multidisciplinary low vision rehabilitation[17]. At a 1 month follow-up of 278 participants, there was a significant improvement in the quality of life assessed by a questionnaire (LVQOL). We also observed in our study that at 1 month interval the QOL of the patients of both group improved which was statistically significant. We also observed that on comparing both the groups the improvement was more in patients prescribed with optical aids than those with non optical aids. Thus we can state that improvement is earlier with optical aids.

Crossland (2007) carried out a qualitative analysis of a small group of patients (N=15) via an open interview before and 3 months after low vision service delivery[18]. Six people specifically mentioned improved quality-of-life with a magnifier.

Wolffsohn et al (2000) investigated the change in vision-related quality-of-life scores (LVQOL) in 117 people, assessed at 4 time points (at time 0, 4 weeks, 8 weeks, and 12 weeks) and found a trend towards a reduction in quality-of-life scores 3 months after baseline measures were implemented, and suggested that outcomes should be assessed up to 2 months post-rehabilitation to avoid a significant decrease in the baseline level of visual impairment during the study period[19].

In our study the patients were also followed in 3^rd month, and we observed that the improvement in the quality of life was statistically significant in both groups. We also observed that on comparing both the groups at 3 month the improvement was more in patients prescribed with optical aids than those with non optical aids. Thus we can state that improvement is better with optical aids.

Ganesh et al, they have used the LVP-FVQ to evaluate the impact of vision rehabilitation on functional vision of children with visual impairment. The study was conducted in 92 subjects in which there was a significant improvement in functional vision post visual rehabilitation, especially with those activities which are related to their academic output.

Scott et al (1999) observed that both the functional status and quality of life improved with low vision aids[20].

Similarly Stelmack J. et al also observed that improvements in both functional status and quality of life occur after low-vision service delivery[21].

We found that compliance with low vision aids was good. 65% of patients using their low vision aids regularly, while 15% do not use them regularly and 20% lost to follow up. Lost to follow up can be attributed to the low educational status of the parents. Training patients for proper usage of the prescribed aid further enhanced the compliance. Also there was a significant psychological adjustment if patients were properly explained about their disease condition.

Similarly a study titled low vision services in South Devon showed a 9 yr compliance of 92%[22]. Thus, if properly counselled and explained LVDs are an effective means of improving visual performance.

The common problems with optical aids were difficulty in copying from blackboard with telescope. But once they become used to the device, the quality of classwork improved. The other important issue was acceptance and adjustment which improves with motivation and support of parents and teachers. The acceptance with non optical aids was observed to be better but result in delayed improvement in quality of life.                                    

LIMITATIONS:

We recognize the limitations of our study, is the small sample size. Due to cost factor limiting the affordability of devices like CCTV could not be prescribed to the patients. Low vision rehabilitation is a multidisciplinary approach and during this study we faced difficulty in training the patients in mobility and daily living skills. Though there have been studies, more extensive research on the characteristics of low vision patients as well as the effectiveness of low vision services in other parts of the country would be helpful in planning nationwide low vision care.

High myopia is favorable for low vision corrections because the vision has usually been poor since childhood and the person has been able to read at close range, producing magnification.

Vision loss early in life has profound functional and psychological implications. Visually impaired children have reduced educational experiences and, later, employment opportunities. Early referral and intervention for a vision problem is critical in maintaining and maximizing the use of functional vision. The use of functional vision is important in maintaining quality of life in these children.

In our study, there was a significant improvement in functional vision post visual rehabilitation in both subsets of myopic children, especially with those activities which are related to their academic output.  Among optical aids, telescopes, dome magnifier and hand held magnifier were very useful in rehabilitation. While much has been said about the optical devices, simple non optical and environmental modifications not only enhance the vision related quality of life on their own they also augment the benefits provided by the optical device. The non-optical aids such as relative distance enlargement and lighting device enhanced subjectively the use of vision in these patients with or without the optical devices. But the optical aids provide earlier and better rehabilitation than non optical aids. It is important for these children to have an early visual rehabilitation to decrease the impairment associated with these decreased visual output and to enhance their learning abilities.

The common problems with optical aids were difficulty in copying from blackboard with telescope. But once they become used to the device, the quality of classwork improved. The other important issue was acceptance and adjustment which improves with motivation and support of parents and teachers. The acceptance with non optical aids was observed to be better but result in delayed improvement in quality of life.       

This study, strongly suggests that more attention needs to be given to the issue of low vision, in view of its importance as a cause of disability and its potential for remedial measures.

1. Visual standards: aspects and standards of vision loss – international council of ophthalmology: reports from 29th International Congress of Ophthalmology. Sydney, Australia, April 2002 World Health Organization.

2. Gillian M. Cochrane, Manjula Marella, Jill E. Keeffeand Ecosse L. Lamoureux et al The Impact of Vision Impairment for Children (IVI_C): Validation of a Vision-Specific Pediatric Quality-of-Life Questionnaire Using Rasch Analysis.
3. Galloway S. Well-being and quality of life: measuring the benefits of culture and sport: a literature review and thinkpiece. Scott Executive Soc Res. 2005;4–97.
4. Ana Hernandez Trillo and Christine M. Dickinson et al The Impact of Visual and Nonvisual Factors on Quality of Life and Adaptation in Adults with Visual Impairment IOVS, June 2012, Vol. 53, No. 7 .
5. Neena J, Rachel J, Praveen V, Murthy GVS, Rapid Assessment of Avoidable Blindness India Study Group. Rapid Assessment of Avoidable Blindness in India. PloS One. 2008;3(8):e2867.
6. Gerald Fonda, M.D. et al low vision correction in myopia,Survey of Ophthalmology Volume 36, Issue 4, January-February 1992, Pages 313-317.

1. Birch, E.E., C.S. Cheng, and J. Felius, Validity and reliability of the Children's Visual Function Questionnaire (CVFQ). J Aapos, 2007. 11(5): p. 473-9.
2. Cochrane, G., E. Lamoureux, and J. Keeffe, Defining the content for a new quality of life questionnaire for students with low vision (the Impact of Vision Impairment on Children: IVI_C). Ophthalmic Epidemiol, 2008. 15(2): p. 114-20.

9. Vijaya K. Gothwal, Jan E. Lovie-Kitchin, and Rishita Nutheti et alThe Development of the LV Prasad-Functional Vision Questionnaire: A Measure of Functional Vision Performance of Visually Impaired Children Investigative Ophthalmology & Visual Science, September  2003;44:4131-4139.DOI:10.1167/iovs.02-1238.
10. Nilsson UL. Visual rehabilitation of patients with advanced stages of glaucoma, optic atrophy, myopia or retinitis pigmentosa. Doc Ophthalmol Adv Ophthalmol. 1988 Dec;70(4):363–83.
11. Ganesh S, Sethi S, Srivastav S, Chaudhary A, Arora P. Impact of low vision rehabilitation on functional vision performance of children with visual impairment. Oman J Ophthalmol. 2013 Sep;6(3):170–4.
12. Corn, A.L., et al., An initial study of reading and comprehension rates for students who received optical devices. Journal of Visual Impairment & Blindness, 2002. 96(5): p. 322-334.
13. Nilsson, U.L. and S.E. Nilsson, Rehabilitation of the visually handicapped with advanced macular degeneration. A follow-up study at the Low Vision Clinic, Department of Ophthalmology, University of Linkoping. Doc Ophthalmol, 1986. 62(4): p. 345-67.
14. Goodrich, G.L., et al., The Reading Behavior Inventory: An Outcome Assessment Tool. Journal of Visual Impairment & Blindness Vol 100(3) Mar 2006, 164-168, 2006.
15. Crossland, M.D., et al., Expectations and perceived benefits of a hospital-based low vision clinic: Results of an exploratory, qualitative research study. Visual Impairment Research, 2007. 9(2-3): p. 59-66.
16. Khan SA. A retrospective study of low-vision cases in an Indian tertiary eye-care hospital. Indian J Ophthalmol. 2000 Sep;48(3):201–7.
17. Wolffsohn JS, Cochrane AL. Design of the low vision quality-of-life questionnaire (LVQOL) and measuring the outcome of low-vision rehabilitation. Am J Ophthalmol. 2000 Dec;130(6):793–802.
18. Crossland, M.D., et al., Expectations and perceived benefits of a hospital-based low vision clinic: Results of an exploratory, qualitative research study. Visual Impairment Research, 2007. 9(2-3): p. 59-66.
19. Wolffsohn, J.S., A.L. Cochrane, and N.A. Watt, Implementation methods for vision related quality of life questionnaires. Br J Ophthalmol, 2000. 84(9): p. 1035-40.
20. Wolffsohn, J.S., A.L. Cochrane, and N.A. Watt, Implementation methods for vision related quality of life questionnaires. Br J Ophthalmol, 2000. 84(9): p. 1035-40.
21. Stelmack, J. and J. Stelmack, Quality of life of low-vision patients and outcomes of low-vision rehabilitation. Optometry & Vision Science, 2001. 78(5): p. 335-42.
22. Shuttleworth GN, Dunlop A, Collins JK, James CR. How effective is an integrated approach to low vision rehabilitation? Two year follow up results from south Devon. Br J Ophthalmol. 1995 Aug;79(8):719–23.