|Year : 2020 | Volume
| Issue : 4 | Page : 258-261
A retrospective study of patients with visual impairment: Its magnitude, causes, and acceptance of the low vision Aids in a tertiary eye care hospital
Annamalai Odayappan1, Tiruvengadakrishnan Nirmala Devi2, Girish Velis3, Priya Sivakumar4, Sivagami Nachiappan5
1 Glaucoma Services, Aravind Eye Hospital, Puducherry, Tamil Nadu, India
2 Neuro-Ophthalmology Services, Aravind Eye Hospital, Chennai, Tamil Nadu, India
3 Department of Ophthalmology, Goa Medical College, Bambolim, Goa, India
4 Neuro-Ophthalmology Services, Aravind Eye Hospital, Puducherry, India
5 General Ophthalmology, Aravind Eye Hospital, Puducherry, India
|Date of Submission||17-Jun-2020|
|Date of Acceptance||07-Aug-2020|
|Date of Web Publication||16-Dec-2020|
Dr. Sivagami Nachiappan
Aravind Eye Hospital, Cuddalore Main Road, Thavalakuppam, Puducherry - 605 007
Source of Support: None, Conflict of Interest: None
Aim: The study aims to highlight the importance of a low vision clinic and give a profile of patients presenting to a low vision clinic at a tertiary eye care hospital. Materials and Methods: Design: Retrospective study. Setting: Institutional. Study population: Details of 9,601 patients who presented to our low vision clinic between January 2009 and June 2015 were analyzed from our database. Data obtained include age group, best-corrected visual acuity, cause of low vision, type of low vision aids (LVA) prescribed, acceptance of the device, and the provision of additional rehabilitation services. Statistical Analysis: Categorical variables were given in the frequency tables with percentages. Results: Around 70.7% of patients were found to have low vision and 29.3% were found to have blindness. We note that 65% of the patients were <40 years of age. The major causes of visual impairment were retinitis pigmentosa, macular degeneration, diabetic retinopathy, pathological myopia, optic atrophy, glaucoma, albinism, and congenital nystagmus. LVA was prescribed to 2689 individuals. The most commonly prescribed LVA were spectacle magnifiers, hand, and stand magnifiers. However, the acceptance rate was just 38%. The rest were given either standard spectacles or were referred to rehabilitation centers if the vision was very poor. Conclusion: There is a young population with visual impairment and highly under-utilized low vision services. Improving the acceptance rate of these devices would help enhance the individual's quality of life part of which could be done by reducing the cost of these devices.
Keywords: Low vision aids, low vision, rehabilitation, visual impairment
|How to cite this article:|
Odayappan A, Nirmala Devi T, Velis G, Sivakumar P, Nachiappan S. A retrospective study of patients with visual impairment: Its magnitude, causes, and acceptance of the low vision Aids in a tertiary eye care hospital. TNOA J Ophthalmic Sci Res 2020;58:258-61
|How to cite this URL:|
Odayappan A, Nirmala Devi T, Velis G, Sivakumar P, Nachiappan S. A retrospective study of patients with visual impairment: Its magnitude, causes, and acceptance of the low vision Aids in a tertiary eye care hospital. TNOA J Ophthalmic Sci Res [serial online] 2020 [cited 2021 Apr 23];58:258-61. Available from: https://www.tnoajosr.com/text.asp?2020/58/4/258/303655
| Introduction|| |
Around 285 million people are estimated to be visually impaired worldwide; the leading causes being uncorrected refractive errors and cataracts. However, these patients are typically not referred to low vision clinics. Only patients with visual acuity <6/18 and nontreatable causes are referred to low vision services.
With the improvement in awareness and cataract surgical coverage, the treatable causes of vision loss are being taken care of to a certain extent; however, those with permanent visual impairment are left in limbo with the only poor prognosis being explained. Not all are referred to low vision services that might help them manage their daily activities by improving their residual vision.
This article aims to highlight the importance of a low vision clinic by giving a profile of patients presenting to such a clinic and discuss the use of various low vision aids (LVA) at a tertiary eye hospital.
| Materials and Methods|| |
This study was conducted at a tertiary eye care hospital with an exclusive low vision unit in India. Institutional Review Board approval was obtained at our institute for this study. This research adhered to the tenets of the Declaration of Helsinki.
Information was obtained from the local database in our hospital and recorded on an Excel sheet (Microsoft Inc.). The database included 9601 patients who presented to our low vision clinic between January 2009 and June 2015.
Data obtained include age group, best-corrected visual acuity (BCVA), cause of low vision, type of LVA prescribed, acceptance of the device, and the provision of additional rehabilitation services.
Visual impairment was classified as low vision and blindness. Low vision includes moderate visual impairment (<6/18 to ≥6/60) and severe visual impairment (<6/60 to ≥3/60). Blindness was described as BCVA <3/60 or a visual field <10 degrees in a radius around central fixation.
Categorical variables were given in the frequency tables with percentages. All statistical analysis was done by statistical software STATA 11.1 (StataCorp, College Station, TX, USA).
| Results|| |
A total of 9601 patients were included in the study. Of the 9583 patients in whom vision was documented, 6,771 (70.5%) were found to have low vision and 2,812 (29.3%) were found to have blindness. Patients were distributed equally between the age groups <15, 16–40, and >40 years [Table 1].
The major causes of visual impairment observed in our tertiary center in Southern India were due to retinal conditions such as macular degeneration, retinitis pigmentosa, diabetic retinopathy, pathological myopia, and albinism. The others being optic atrophy, glaucoma, and other causes of childhood blindness such as congenital optic atrophy and congenital nystagmus [Table 2].
Of the 8767 patients in whom the data on the prescription of LVA was available, we find that it was prescribed to 2689 individuals [Figure 1]. Rest were given either standard prescription spectacles or, if the vision was very poor that LVA could not be given, they were referred to rehabilitation centers. [Table 3] shows the various LVA prescribed across all age groups.
The most common LVA prescribed were the hand and stand magnifiers that include bar magnifiers, dome magnifiers, book magnifiers, wallet magnifiers, and the spectacle magnifiers such as aspheric lenses and prismospheres. The other LVA prescribed include telescopes for distance vision, electronic devices such as closed-circuit television, and other nonoptical aids such as long white cane, writing guide, money identifier, signature guide, reading lamps, absorptive glasses, flashlight, wide-brimmed hat, and reading stand.
Among the 2,689 individuals in whom the LVA were prescribed, only 1025 individuals obtained the device; the acceptance rate being just 38.1% [Figure 2].
|Figure 2: Bar diagram showing acceptance of low vision aids among those who were prescribed|
Click here to view
| Discussion|| |
As per the cumulative official updates to the International Classification of Diseases-10 by the WHO in January 2015, a person is said to have low vision if the presenting distance visual acuity is between 6/18 and 3/60. This includes moderate (<6/18 to ≥6/60) and severe visual impairment (<6/60 to ≥3/60). Blindness is described as a presenting distance visual acuity is <3/60 or a visual field <10 degree in a radius around central fixation in the better eye.
There have been several studies on the demographics in a low vision clinic.,,,,, Around 65% of our patients were <40 years of age. This is in agreement with other studies from developing nations where there is a larger proportion of younger individuals with visual impairment as compared to developed countries.,,,
Not all who were prescribed LVA would buy them due to various factors such as cost, difficulty in usage, cosmetic reasons, portability issues, and we find that the acceptance rate was a meager 38%. Mohidin and Yusoff reported an acceptance rate of 59.5% in Malaysia. Gao et al. reported an acceptance rate of 76.1% in China.
Younger individuals seem to accept spectacle magnifiers better probably because both hands are free to move a textbook. Hand and stand magnifiers seem to be better accepted across all age groups and are more preferred by the elderly. Telescopes and electronic devices are among the least accepted devices.
If the vision was very poor that LVA could not improve the existing vision, the individuals were referred to specific rehabilitation centers. After the assessment, children were suggested either integrated education in normal schools or special education in specific schools for the blind. Adults were provided with vocational guidance where they are taught some specific skills which help in providing employment opportunities and social rehabilitation where they are taught how to manage their day–to-day activities.
This, being a retrospective study, has its inherent limitations. The cause of the visual impairment in each of the age groups could not be determined. Disease-specific LVA could not be noted. Whether the patients who bought the device were actually using it at home could not be ascertained.
| Conclusion|| |
In conclusion, hand and stand magnifiers are the most commonly used and the most accepted devices. It would be better to try these first when the person visits a low vision clinic to get them oriented to the devices before trying more cumbersome aids such as telescopes and electronic devices. This study likely shows only the tip of the iceberg of visual impairment in the community. In spite of the heavy burden of visual impairment, low vision services are scarce and under-utilized. Either such individuals who need those services do not visit the hospital, or even if expert opinion is sought, they are explained about the poor visual prognosis but not referred to appropriate low vision clinics. By referring to all patients fulfilling the criteria for low vision to low vision clinics, we can have complete utilization of these services. Probably, if more governmental and nongovernmental organizations could be involved, the cost of these devices could be reduced further, thereby improving the acceptance rate of LVA that would help improve the individual's quality of life.
Our Statistician, Mrs. Iswarya.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]