A novel strategy for management of uncorrected refractive errors in urban slums.

BACKGROUND: Blindness and Vision impairment remains a major public health issue not only in rural but also in urban areas. Concept of using peripheral health centers to render primary health care services to the community was a WHO proposed model. However, establishing them in urban slums is a challenge as most of the slums are illegal establishments. So, aim was to establish vision centers for providing primary eye care services in the urban slums of Mumbai, West India.
METHODS: Vision centers were established in various slum pockets of Mumbai from the year 2008 till 2009. Refraction and screening for ocular morbidity were carried out for those who attended this center and management for uncorrected refractive errors was done.
RESULTS: Data from 6 such vision centers located in various slum pockets of Mumbai city from April 9 to March 2011 were collected and analyzed. Of the 19,550 adults, 2270 (11.61%) had moderate vision impairment with presenting visual acuity of <0.5 LogMAR in both eyes. Severe Visual impairment was seen in (723) 3.70%. Blindness was seen in (357) 1.82%. Of the 2993, which were moderately and severely visually impaired, 1893 subjects that is, 63.24% of them improved to 0.2 LogMAR or better with spectacle correction.
CONCLUSIONS: About 63.24% of visual impairment was due to uncorrected refractive errors, these included both moderately and severely vision impaired. Totally, 357 (1.82%) were also identified as blind. This model of vision centers has a role in the identification and management of sight-threatening problems.

Introduction

Uncorrected refractive error is one of the leading causes of avoidable blindness.[1] WHO defines visual Impairment as presenting visual acuity (VA) less than 6/18 in meters in the better eye with available correction.[2] Blindness and vision impairment remains a major public health issue not only in rural but also in urban areas. Studies have revealed that besides economic reasons; lack of awareness is among the biggest barriers for availing refractive error services.[3]

Mumbai is one of the most populated cities in India.[4] Being the business capital of India, migrants from different states come to reside in the city for better employment opportunities. This has further led to a large number of people living in slums and illegal establishments. Lack of access to health services and lack of awareness is a serious public health issue.[45]

Concept of using peripheral health centers to reach primary health care services to the community was a WHO proposed model. This strategy has been well established in the rural India but not in urban population including urban slums. To render primary eye care services, vision centers are a strategy that has been proposed and implemented to achieve “Vision 2020: The Right to Sight” objective. The concept of vision center was established due to the fact of increasing blindness due to cataract, uncorrected refractive error, childhood blindness, low vision, glaucoma and diabetic retinopathy in the country.[6] There is ample of evidence that suggests that blindness contributes to poverty at community levels. These problems have 75% effective and cost effective solutions with significant positive impact for better social and well-being to millions of people. Public-private partnerships with cost-effective new technologies can be integrated with training and research to develop better health care delivery systems. However, establishing vision centers in urban slums was a challenge as most of them are illegal establishments. We report here a novel strategy of providing primary eye care and refractive error services to the urban slum populations through the development and implementation of a vision center strategy.

Methods

Mumbai Eye Care Campaign covers a population of Mumbai city and suburban areas that are 12.5 million.[7] A situation analysis revealed need for primary eye care services among the slum population residing in Mumbai. Therefore, a pilot project was developed in 2008 and implemented in Dharavi, one of Mumbai's largest slums, and also vision centers on Community Based Organization (CBO) premises were established. The pilot project proved to be operational where the CBO would provide space once a week for rendering eye care services to the community. These CBOs are either places like a temple or church or work for other causes like tuberculosis and child labor. They grant space once a week to provide primary eye care services and on the other days, carry their own activity. This model was further replicated to 7centers across the slums of Bandra and Malad till 2009.

Definitions

Moderate Visual impairment was defined as presenting VA of <0.6 but ≥1.0 LogMAR in both eyes, whereas, Severe visual impairment was defined as VA of <1.0 but ≥to 1.3 LogMAR.[8]

Blindness is defined as, having presenting distance VA of < 1.3 LogMAR based on International Classification of Disease-10.[8]

Functional presbyopia was defined as needing a significant optical correction added to the presenting distance refractive correction to achieve a near VA of >1, and 1M for near.[91011] Objective presbyopia is defined as needing a significant optical correction of + 1.00 D added to the best distance optical correction to improve near vision to a near VA of 1M.[1213]

Field work

Door to door screening was carried out by community health workers, who have been given comprehensive training on vision screening, communication and counseling skills. The screeners designed for this study where vision screening was done using screeners with a 6/60 and 6/12 optotypes, designed for recording VA at 3 m. This screener was almost similar to RAAB screeners except for 6/18 optotype 6/12 was used.[14] The screeners also have a 1M and 4M lines to be recorded for near vision. People who failed to read the 6/12 and or the 1M line were referred to the nearest vision center.

Clinical eye examination

Each vision center consisted like LogMAR light box, trial boxes, lensometer, retinoscope, and ophthalmoscope. On specific days of the week, vision centers operate four times in a month, and some are functional twice a month. Patients visiting these centers underwent an eye examination. They were examined by interns of a 4 years optometry program under faculty supervision. Each patient underwent an evaluation that included presenting VA measured on illuminated LogMAR light box at 4 meters, objective refraction was carried out on subjects who's presenting VA with and without glasses were recorded to be 0.2 LogMAR or worse in either eye and subjective refraction pupil evaluation, torch light examination for anterior segment, cover test, and ocular motility were performed. For patients who were above the age of 35 years, intra ocular pressure was assessed using a Pulsair intelliPuff Tonometer, and optic disk was evaluated for cup disc ratio using a Keeler-professional direct ophthalmoscope. Following refraction, those who required spectacles, frame selection and fitting was done and the spectacles were delivered 2 weeks later at no cost. For those who had only near correction, near vision glasses were dispensed immediately and were instructed about their wear and use of the same.

Those who required further evaluation were referred to base hospital. The protocol followed was in the provision of the declaration of Helsinki for research involving human subjects.

Results

Over 2 years of Mumbai Eye Care Campaign, 252,055 of people were screened by door to door screening. 19,550 adults and 1004 children were examined. Of the 19,550 adults (2270) 11.61%, had moderate vision impairment with presenting VA of < 0.6 LogMAR. Severe Visual impairment was seen in (723) 3.70%. Blindness was seen in (357) 1.82% [Table 1]. Of the 2993, which were moderately and severely visually impaired, 1893 subjects that is, 63.24% of them improved to 0.2 LogMAR or better with spectacle correction [Figure 1].

Table 1

Number of patients in each category of visual impairment based on ICD-10

Figure 1

Number of patients having best-corrected visual acuity of 0.2 log or more in each of the vision impairment categories

Among the 723 identified with severe impairment, 32.22% (233) showed improvement in VA and became normally sighted.

Figure 2 shows the ocular morbidity seen in the screened population causing vision impairment.

Figure 2

Distribution of ocular morbidity in studied population

As these vision centers are located on CBO premises, the cost of equipping each center is USD 2222, the service delivery cost per person from College perspective is 24 cents. The custom-made prescription glasses are each for USD 4.4 and a near vision spectacle for USD 1.66 The service delivery standard of the vision centers is on par as a spectacle compliance study revealed a compliance of 70%,

Discussion

In 2008, a pilot study was done for rendering services for uncorrected refractive errors in Dharavi, which is considered as Asia largest slum.[5] The pilot study revealed that 96% of presbyopia is uncorrected. These results are similar to previously reported studies on burden of presbyopia.[12] Prevalence of uncorrected refractive errors in 2001 survey of National Program of Control of Blindness, India is estimated to be 20%.[15]

Utilizing peripheral health centers for service delivery has been a successful model for providing primary health care services in India.[16] LVPEI model of vision centers for providing primary eye care services in rural India has been operational since 2003 and till 2011 reached out to over 6,00,000 people. Vision centers are useful in providing basic eye care services within the community and providing a good referral system. By creating access locally, people do not have to travel and will thereby avail services. Since 80% of the causes of treatable blindness are cataract and uncorrected refractive errors, these centers share the burden of detection and management of uncorrected refractive errors and detection of cataracts and referral to tertiary care centers.[15]

This urban model of vision centers has been developed keeping in mind effective and efficient utilization of resources that includes space, human resources, and equipment. In urban cities, space is one of the major constraints and real estate rates are high. So this model uses space available once a week on the premises of CBOs. Similarly, the same human resource team comprising of optometrists and camp supervisor work at different vision centers on different days of the week. The limitation of this model is largely due to the scope and practice of Optometry India at this point of time. As optometrists are not permitted to prescribe therapeutics, the referral rate to tertiary centers for basic eye infections and inflammations is relatively high.

Service delivery using vision centers was proposed by LVPEI in the eye health pyramid model.[17] The model recommended one vision center per 50,000 people. According to the publication by World Bank,[18] 45.04% of the population in urban cities in regions like Asia Pacific, Middle East, North Africa, Eastern Europe, Latin America, etc., resides in slums. This urban poor has purchasing power parity of less than 2.15 USD per day. Considering this situation globally that the slum population is growing by 6 million every year, this model of service delivery will help alleviate vision impairment cost effectively.[19]

Conclusion

We found that 63.24% of the visual impairment was due to uncorrected refractive errors. About 32.2% of the severely impaired improved with a pair of spectacles. The model demonstrates that in the absence of service delivery, these patients would be visually disabled and same can be alleviated with a simple pair of spectacles. Besides uncorrected refractive errors, this model of vision center has a role in the identification of other ocular morbidity and timely referral for vision related problems. The model in the pilot project started off with three vision centers and was later scaled up to 15 vision centers across the city. Hence, the model further demonstrates that this can be adapted in other urban slums and underprivileged areas as primary eye care service delivery option, which is both efficient and cost effective.