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Original Article

Demographic and clinical profile of patients presenting at the low vision clinic of a tertiary eye care facility in Kerala ABSTRACT Aim: To analyze the demographic and clinical profile of patients attending the low vision clinic of a tertiary eye care facility in Kerala. Materials and Methods: This was a cross‑sectional observational study at the low vision clinic of a tertiary eye care facility in Kerala between May 2007 and May 2016. Information regarding the demographic and clinical characteristics of the patients and low vision rehabilitation done were recorded. Results: Out of the total 916 new patients, 51.31% were males and 48.69% were females. Thirty‑three percent were above 60 years, 26.24% were between 40 and 60 years, 16.11% were between 17 and 35 years. Mean age was 51.2 ± 23.5 years. Major etiological diseases were age‑related macular degeneration (18.51%), diabetic retinopathy (18.1%), optic atrophy (14.2%), retinitis pigmentosa (13.03%), etc. A total of 39.94% were prescribed high plus spectacles, 35.64% stand magnifiers, 15.39% bifocal spectacles, and had 9.01% hand magnifiers. Conclusion: The demographic and clinical characteristics of low vision patients of the study population are similar to that of the developed countries. The barriers to utilization of resources need to be analyzed through further studies. Key words: Demography; Low vision; Kerala.

Introduction Low vision is impaired visual function despite treatment of eye disease and/or correction of refractive error, and is defined as reduced visual acuity in the better eye less than 6/18 but better than light perception or a visual field constriction to less than 10°, with a potential to use vision for planning and/or execution of a task.[1] This definition of low vision excludes individuals whose visual acuity could be improved by surgical and/or medical treatment and refers to functional vision. According to the World Health Organization estimates (WHO), there are 45 million blind and 135 million individuals with low vision. Approximately 90% of the blind population live in the developing world.[2] It is estimated that there are 9–12 million blind in India, which amounts to approximately one‑fourth of all the blind people worldwide.[3,4] A survey in 1986 by the WHO and National Programme on Prevention and Control of Blindness (NPCB) Access this article online Website: www.kjophthal.com

DOI: 10.4103/0976-6677.193866

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in India showed that 10% of the 9.61, that is 0.96 million persons, have incurable blindness and would require rehabilitation services. It has been observed that almost 90% of the so‑called blind population do not have total loss of visual function but retain a degree of useable residual vision.[5] Low vision is an important public health problem and provision of low vision services is one of the priorities in the global initiative, Vision 2020—The Right to Sight. Given the high Sanitha Sathyan, Jasmine Davis, Rosemary C. Antony, Susan Mathew, R. Jyothi Department of Ophthalmology, Little Flower Hospital and Research Centre, Angamaly, Kerala, India Address for correspondence: Dr. Sanitha Sathyan, Department of Ophthalmology, Little Flower Hospital and Research Centre, Angamaly, Kerala, India. E‑mail: [email protected]

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How to cite this article: Sathyan S, Davis J, Antony RC, Mathew S, Jyothi R. Demographic and clinical profile of patients presenting at the low vision clinic of a tertiary eye care facility in Kerala. Kerala J Ophthalmol 2016;28:48-52.

© 2016 Kerala Journal of Ophthalmology | Published by Wolters Kluwer - Medknow


Sathyan, et al.: Low vision, Kerala

burden of low vision and blindness, there is a great need for strengthening low‑vision services in India. Although there has been an increase in awareness of low‑vision services among ophthalmic professionals in India, effective strengthening of these services has not been materialized so far.[6] Kerala, with its high Human Developmental Index, has made commendable progress in the prevention of avoidable blindness. However, low vision has remained a no man’s land and accurate data on accessibility and effectiveness of low vision services from the State is currently lacking. Ageing and increased life expectancy also increase the population with disease conditions that result in low vision. It is highly likely that the number of people living with low vision will increase over the coming decades due to the rampant effects of diabetic retinopathy, age‑related macular degeneration, etc., in our population. The challenge of rehabilitating such increasing numbers is enormous and requires appropriate strategic planning and efficient use of available resources. It is, therefore, important to collect and analyze clinical data from patients with functional low vision in order to deliver appropriate low vision care. In order to plan appropriate low‑vision rehabilitation strategies, we need reliable and up‑to‑date information on low‑vision patients in our State. Such information is not readily available at present. Hence, this study was conducted to address this issue. Aim To analyze the demographic and clinical profile of patients attending the low vision clinic of a tertiary eye care facility in Kerala.

Materials and Methods This was a cross‑sectional study of all patients seen at the low vision clinic of a tertiary care ophthalmic facility between May 2007 and May 2016. Study location was a teaching hospital and a major provider of tertiary healthcare in Kerala. The low vision clinic was established in 2007. It is located in the eye clinic of the hospital with a dedicated room equipped for evaluation and testing of patients with low vision. Study population Patients who attended the low vision clinic comprise those who have been treated at the tertiary care eye hospital for various ailments but whose vision needs were not adequately met by conventional methods in accordance with the definition of low vision.[1] Other sources of referral included private and Government eye clinics in Kerala. All patients presenting to the low vision clinic are seen by an ophthalmologist and an

optometrist who has received subspecialty training in low vision services. Low vision devices are available for purchase by clients as soon as they are prescribed. All the patients seen during the study period were examined and tested with different low vision devices by the attending low vision specialist. Information on the demographic and clinical characteristics of the patients was recorded. Visual acuity (VA) was assessed with the use of early treatment diabetic retinopathy study (ETDRS) charts and log MAR for near vision. Distance visual acuity of counting fingers, hand motion, light perception (LP), and nil light perception (NLP) were assigned log MAR values of 1.9, 2.3, 2.7, and 3.0 respectively.[7,8] Color vision was tested by Ishihara chart. The study protocol adhered to the tenets of the Declaration of Helsinki for research involving human participants, and verbal informed consent was obtained from study participants. Ethical approval was obtained from the ethics committee of the hospital. The data was analyzed with the use of Statistical Package for Social Sciences version 17 software (SPSS Inc., Chicago, Illinois, United States of America).

Results A total of 916 new patients presented and were seen at the low vision clinic during the study period. The mean age was 51.2 ± 23.5 years (range: 6 to 90 years). Four hundred and seventy (51.31%) were males, and 446 (48.69%) were females. The mean age of the male patients was 53.6 ± 13.63 years whereas that of females was 27.0 ± 18.54 years. Thirty‑three percent were above the age of 60 years, 26.24% were between 40 and 60 years, and 16.11% were between 17 and 35 years. The above 60 years age group had the largest proportion with 33% of patients; followed by the 46–60 years age group (26%). Demographic characteristics of the population are shown in Tables 1‑5 and Figures 1‑6.

Discussion This study describes the demographic and clinical characteristics of patients presenting to the low vision clinic of a tertiary care teaching hospital in the State of Kerala. To the best of our knowledge, there are no previous reports of such clinical studies from the State, as there are a very few low vision clinics functioning in the area. Nine hundred and sixteen patients were seen at our low vision clinic during the period 2007–2016. This comprises 0.07% of the total outpatient attendance during the period.

Kerala Journal of Ophthalmology / January-April 2016 / Volume 28 / Issue 1

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Table 1: Age distribution of the patients Age group

Frequency

Males

Females

0-16 17-35 36-45 46-60 Above 60

133 (15%) 151 (16%) 87 (10%) 241 (26%) 304 (33%)

73 89 50 164 215

60 62 37 77 89

Table 2: Presenting distance visual acuity of the patients Age group

0.5‑0.8 logMAR

1‑1.3logMAR

N40

62 33 11 23 43

52 40 46 158 195

13 36 10 20 29

2 50 9 12 23

4 27 11 20 14

This is much less than the prevalence of low vision sited by population‑based studies conducted in South India.[18] This raises concerns about the access and awareness regarding low vision services in our community. According to a questionnaire‑based study conducted by Khan et al.,[9] lack of awareness, training/knowledge among health care workers, and nonavailability of low vision devices were perceived as the major barriers to providing low vision care in India. Barrier to the access of low vision care in our area needs to be studied in detail for strategic planning. Majority of available data on patients with low vision are derived from population surveys. However, these were not designed to study functional low vision of the patients. Hospital studies are capable of providing more detailed information on the clinical characteristics of the patients attending low vision clinics. [10] A major advantage of clinic‑based studies is that they provide more reliable and usually detailed ophthalmic information regarding people with low vision.[11] Because our study was based on clinical population, we could look more into the clinical data as well. We believe that the information about patients who actually attend low vision clinics would be useful for planning and delivering effective low vision services. However, it has to be acknowledged that this data is not representative of the community prevalence and characteristics of our state as the turnover of patients for 50

Figure 2: Distribution of BCVA for distance

Figure 3: Distribution of near visual acuity

low vision services was very low. However, such data is clinic‑specific and can be influenced by the sources of referral as well as awareness, level of acceptance, and cultural and social aspects of the population. As the sample sizes of such studies are often small, they are prone to sampling errors and may not be extrapolated to the general population.[12] However, the use of this data in local planning and execution models cannot be overemphasized.[13] The age distribution of our patients is different from previous reports from developing countries, however, is similar to




Figure 4: Age‑wise distribution of etiological diseases

Figure 5: Etiological diseases in the less than 16 years of age population

Table 4: Etiological diseases in each age group Etiology RP ARMD DR Pathologic myopia Macular dystrophy Optic atrophy Glaucoma Albinism Corneal opacity Macular scar Amblyopia Macular hole Aphakia Pseudophakia Old retinal detachment Coloboma

0‑16 years

17‑35 years

36‑45 years

46‑60 years

Above 60 years

11 0 0 0 0 40 0 3 2 4 22 0 5 3 4 20

19 5 0 3 1 12 1 1 0 2 11 3 5 7 4 11

29 30 11 3 12 9 1 0 1 1 2 0 0 11 3 1

20 25 62 9 36 30 1 0 1 12 3 6 0 0 1 0

16 75 59 3 31 13 8 0 5 9 3 18 0 0 2 2

Table 5: Low vision aids prescribed

0-16 years 17‑35 years 36‑45 years 46‑60 years above 60 years

Spectacle

Hand magnifier

Stand magnifier

Bifocal spectacles

24 34 25 102 103

2 15 2 13 33

38 47 21 67 84

3 18 19 42 29

those from other developed countries. The incidence of low vision has been reported to increase with age.[11] In our study population, 33% of the patients were above 60 years and 26% were 45–60 years of age. This is in contrast to a study conducted in India, 20 in which 68% of the patients attending the low vision clinic were below 50 years of age. Similarly, studies from developing countries such as Korea,[13] Malaysia,[14] and Nepal[15] depict a younger population as the majority attending low vision care. In these studies, the proportion of low vision patients aged 60 years and above ranged between 16 and 26%.

On the other hand, in a study from the United Kingdom, Leat and Rumney[17] found that 77% of the patients were aged 60 years and above; Elliot et al.[12] from Canada reported that 66% of patients were 70 years or older; whereas in Australia, Wolffsohn and Cochrane[11] observed that 87% of patients were aged 60 years and above. This difference in the pattern of age distribution may be related to the difference in life expectancy between developed[12] and developing countries.[14,16,19] Posterior segment disease accounted for the majority of causes of low vision in this study. This correlates with findings of most low vision clinic studies.[11,13,14] Khan et al. found retinitis pigmentosa to be the most common cause in a population of 410 low vision patients in India;[16] Mohidin and Yusoff observed it to be the second most common cause in a Malaysian low vision clinic.[14] These were similar to our study.


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Conflicts of interest There are no conflicts of interest.

References 1. 2. 3. 4. Figure 6: Age‑wise distribution of the low vision aids provided

Glaucoma occupied the fourth position as a cause of low vision/blindness in the population (5.8%) according to the Chennai Glaucoma study.[18] However, the number of glaucoma patients attending low vision clinic was very low in our study. This may be due to the small sample size. However, poor uptake of low vision services by patients with glaucoma raises questions on community and health personal awareness as well. This was true in case of references on diabetic retinopathy also. Regarding the low vision rehabilitation strategies, it was seen that a significant number of patients benefitted from careful refraction followed by standard prescription of high power basic spectacles with spherical glass lenses and lenticular spherical lenses, ranging from 12 to 24 diopters in power. These were available at INR 300–800, and highlights the point that low‑vision care need not be always expensive.

5. 6.

7.

8.

9.

10.

11.

Conclusions

12.

The demographic and clinical characteristics of low vision patients in our setting are similar to those of the developed countries. A huge disparity exists between the number of patients with low vision and those seeking low vision care. The barriers to utilization of resources need to be analyzed through further studies. More extensive research on the characteristics of clinical and psychological aspects of low vision patients as well as the determinants of utilization of services are necessary for future planning and delivery of services.

13.

Financial support and sponsorship Nil.

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14. 15. 16. 17. 18.

19.

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