Wong, Elaine Y. H.; O'Connor, Patricia M.*; Keeffe, Jill E.*
Vision impairment (VI) is an increasing global problem. Current estimates are that 161 million people worldwide have low vision and 37 million of these are blind. Without effective intervention, the number of people with low vision will increase significantly by 2020.1 This will not only have significant implications for productivity2,3 but also poses a huge burden on the rehabilitation services that are currently available.
An estimated 70 million people globally could need low vision services, yet only 5 to 10% accesses such services.4 Much has been written on the patient and service-related barriers that contribute to this mismatch between need and uptake.5–11 What remains to be answered is the extent to which current models of low vision care can suitably meet the needs of the low vision population they serve.
Low vision services should be provided at primary, secondary, and tertiary levels. At the primary level, low vision care involves screening of vision, simple advice on environmental modifications, and non-optical interventions. At the tertiary level, a team of trained professionals provide care that involves assessment of visual function, refraction, prescription and use of full range optical, non-optical and electronic low visual aids, multidisciplinary rehabilitation, and training in visual skills and mobility.4 Secondary level care serves the critical interface between these two levels. As suggested by World Health Organization (WHO), secondary level low vision clinics (LVCs) should use the expertise of existing eye health personnel,12 such as ophthalmologists, optometrists, or orthoptists, and be equipped with a limited range of magnifiers.13 Individuals who require occupational therapy (OT) or orientation and mobility (O&M) assistance or the use of high magnification magnifiers, are best catered for in a tertiary level clinic. Another model of vision rehabilitation has also been developed, such as SmartSight by the American Academy of Ophthalmology.14 It consists of four levels of care, with an additional basic level (level 1), where eye care providers are urged to “Recognize and Respond” to patients with low vision. Levels 2, 3, and 4 are similar to WHO's primary, secondary, and tertiary level of care.
The WHO has produced estimates of the extent to which the needs of the low vision population can be met by the three different levels of service provision. Primary level low vision services should be able to meet the needs of 30% of the low vision population, a further 20% should be met by the tertiary level care, whereas the needs of the remaining 50% of the low vision population could potentially be appropriately met in a secondary level LVC.12
In Australia, low vision services are typically provided as specialist tertiary services by non-government organizations.15 Few primary or secondary level low vision services are available and low-vision rehabilitation is not usually integrated into the public or private health care system. As a result, many patients who could benefit from such services are not receiving them as part of a continuum of care. Instead, patients who attend a hospital or private clinic for medical care will then need referral for low vision services to tertiary level LVCs operated entirely by non-government organizations such as Vision Australia and Guide Dogs Australia. This, therefore, limits access to low vision rehabilitation.
One major concern of this tertiary-led model is that not all patients with low vision require all the services it provides. A study of more than 300 people has shown that only 43% of people attending tertiary level low vision services required the full range of services provided.16 Critically, more than half did not. This suggests that, as the WHO advocated, secondary level LVCs could provide the optimum level of service to meet the needs of a significant proportion of people with low vision. According to the WHO, secondary level LVCs should be “add-on,” integrated services to existing eye care services and can provide vision training, basic rehabilitation services, equipment, and low vision devices (LVDs).12 They can make referrals to tertiary services when required. Although such a secondary level LVC is currently being established in Melbourne, Australia, this clinic is still in its infancy and, at this stage, lacks the case base to test the WHO hypothesis. The aim of this article is to assess the potential service capacity of secondary LVCs by extrapolating data from within the current tertiary system of delivery.
A retrospective study of clinical records was conducted of all first-time clients to the LVC at Vision Australia, Kooyong, Australia, between March 2000 and May 2002. It is the main tertiary level provider of low vision rehabilitation services to residents of urban and rural Victoria and is the largest of three such services in metropolitan Melbourne, Australia. The clinic is staffed by low vision advisors, social workers, O&M instructors, orthoptists (vision therapists), occupational therapists, and optometrists. Once referred by eye care providers, clients were initially contacted by low vision advisors to discuss their visual needs and were all invited to attend the LVC. All 15 attending optometrists held a postgraduate diploma in rehabilitation of the visually impaired. During this visit, optometrists assessed the client's visual needs and depending on the acuity required, determined the most appropriate LVDs for trial or purchase. In addition, optometrists established whether the clients require further orthoptics, O&M, or OT reviews. Additionally, low vision advisors with a background in social work played an important role in linking clients to services and interest groups, assisting them in applying for eligible concessions and providing necessary counseling. Orthoptists, who specialize in low vision, provided lighting advice, ergonomic issues, LVD training, visual field testing, and eccentric viewing. O&M instructors assisted clients to navigate safely and independently using mobility devices. OTs helped to retrain individuals for common daily living activities such as writing, cooking, pouring, and cleaning. All clients of the clinic receive free services and discounted spectacles. However, they have to bear the full costs of LVDs required.
Data retrieved from patient records included demographic features, causes of VI, clients' goals of rehabilitation, distance and near visual acuities (VA), LVDs demonstrated, loaned or purchased by clients and auxiliary services received. The main cause of VI of each client was determined and was each assigned into one of five broad categories: (1) age-related macular degeneration, (2) glaucoma, (3) diabetic retinopathy, (4) other retinopathies, and (5) other eye diseases. Clients' self-assessed rehabilitation goals were recorded and categorized into six general themes based on all goals reported: (1) reading and near tasks, (2) LVDs, (3) general vision (including distance vision), (4) independence, (5) general support, and (6) not defined. Distance and near VA were measured by Bailey-Lovie distance logarithm of the minimum angle of resolution (logMAR) chart and Bailey-Lovie near chart.17 Clients with distance vision of <6/12 to 6/18 (logMAR 0.4 to 0.5) and ≥6/12 (logMAR ≤0.3) with visual field loss were considered as having mild VI. Those with VA <6/18 to 6/60 (log MAR 0.6 to 1.0) as having moderate VI and those with worse than 6/60 (logMAR >1.0) vision as having severe VI. Near vision was recorded using the N notation, which was the smallest size print that could read at patients' preferred viewing distance with spectacles or LVDs. When testing with LVDs, clients' best corrected near vision spectacles were used and while the viewing distance, position of magnifiers and reading chart were optimized.
LVDs that were demonstrated, loaned for home trial for 2 to 4 weeks, prescribed and those that were eventually purchased by the clients were all recorded. These included high addition spectacles, handheld, stand, spectacle-mounted (clip-on plus lenses) or around-the-neck embroidery magnifiers, telescopes and closed circuit televisions (CCTV). Magnification recorded, where appropriate, was described in terms of mean maximum magnification that is F/4 + 1 (where F is the equivalent power). LVDs of ≤2× [≤+8.00 dioptres (D)] magnification were recorded as low power magnification; >2 to 5× magnification as moderate; and >5× magnification as high.
Participants who could have only used secondary level low vision services, such as low or moderate magnification LVDs, low vision and welfare advisors and orthoptists, were identified. In addition, those who actually required tertiary services, such as those who used O&M or OT or high magnification LVDs, were documented.
All data were entered into Microsoft Office Excel 2003 SP2 and later transferred and recoded in SPSS 17.0.1 (SPSS, Chicago, IL) for statistical analysis. As the data were non-parametric, Pearson χ2 test was used to compare proportions and multiple logistic regressions were used to explore relationships between vision and the use of magnifiers, O&M and OT, controlling for age, gender, cause of vision loss, and goals of rehabilitation. A p value of <0.05 was considered statistically significant. Ethics approval for this study was obtained from the Royal Victorian Eye and Ear Hospital Human Research and Ethics Committee and the research adhered to the tenets of the Declaration of Helsinki.
Clinical and rehabilitation records of first-time clients to the LVC between January 2000 and December 2002 were reviewed (n = 192). Of these, 65% were female with a mean age of 76.3 years (SD ± 13.0, range 19 to 100). Although the majority of clients (60%) had age-related macular degeneration as the main cause of vision loss, most presented with mild (32%) or moderate (49%) VI and 83% were able to read better than N20 with their current reading spectacles. The most frequently cited goals for low vision rehabilitation were either to obtain LVDs (32%) or to improve reading and near tasks (23%; Table 1).
Distance refraction was performed on all clients and 49 (26%) purchased new distance spectacles with 34 of them (18%) able to achieve vision better than 6/18 (logMAR <0.6). Of the 49 who purchased new distance spectacles, 31% (15/29) had no measured improvement in best-corrected VA, 53% (26/49) had 1 to 2 lines of improvement on Bailey-Lovie distance logMAR chart, 12% (6/49) had 3 to 4 lines of improvement, and 4% (2/49) had more than 5 lines of improvement. Of the 143 clients who did not purchase new distance spectacles, the majority of them (88/143, 62%) had no visual benefits from a new refraction. However, 54 clients (38%) had 1 to 2 lines of improvement and a further one (<1%) had 3 to 4 lines of improvement, yet declined to purchase new spectacles.
In addition, 178 (93%) of clients had a near prescription determined and 41% (73/178) of them purchased new reading spectacles (single vision, bifocal, or multifocal) with their appropriate distance and astigmatic correction incorporated (Table 2). The majority of those who purchased spectacles for reading had a near vision of N10 to N20 (51%, p = 0.02) and most of them (67%, 49/73) were prescribed additions of ≤+4.00 D. Thirteen (18%) were either +6.00 or +8.00 D near additions and 11 (15%) had additions of +10.00 or +12.00 D (Fig. 1). Pearson χ2 test indicated that, there was no statistically significant difference between the group who purchased and those who did not purchase distance and near spectacles in terms of age (p = 0.75 and p = 0.51), gender (p = 0.57 and p = 0.74), cause of vision loss (p = 0.30 and p = 0.66), and rehabilitation goal/theme (p = 0.96 and p = 0.53).
The most common LVDs demonstrated to patients were handheld magnifiers (HM) (72%, 138/192). Using HMs, 34% of clients had 1 to 2 lines of vision improvement at near, 31% have 3 to 4 lines of improvement, and 27% with >5 lines of improvement. In total, 113 (59%) were able to achieve better than N8 print, but only 58/192 (30%) purchased an HM. Of these, 90% (52/58) were of moderate magnification, 7% were low, and 3% were high magnification (Fig. 1).
Fewer (32%, 61/192) had stand magnifiers (SMs) demonstrated to them. However, the SMs demonstrated were more likely to be of high magnification compared with the HMs (43 vs. 18%, p = 0.02; Fig. 1). Of those clients who had SMs demonstrated 22% had 1 to 2 lines of vision improvement, 28% had 3 to 4 lines of improvement, and >40% had at least 5 lines of vision improvement. Despite this, only nine of the 20 clients who achieved >5 lines of vision improvement and 19 of 47 clients (40%) who achieved better than N8 vision purchased an SM at the end of the consultation. Of the total 20 clients who purchased an SM, only one (5%) was of low magnification, 11 (55%) were moderate magnification, and eight (40%) were high magnification. Of the 11 who did not purchase an SM, eight were able to achieve N8 or better vision.
The use of telescopes to improve distance vision was occasionally recommended in the clinic. Only 12 of the 192 participants trialed a telescope. Of these, four achieved vision better than 6/12, another four were able to see <6/12 to 6/18, three improved vision to <6/18 to 6/60, and one achieved vision <6/60. Six of these (50%) had >5 lines of vision improvement, four (33%) achieved 3 to 4 lines of improvement, and two (17%) obtained 1 to 2 lines of improvement. However, only two telescopes were purchased and these were acquired by participants who could achieve vision better than 6/12 (logMAR <0.3) with the aid of the telescopes.
Around-the-neck embroidery magnifiers of 2× magnifications were recommended to 14 participants but were purchased by only five of them. Spectacle-mounted magnifiers (clip-on plus lenses) were demonstrated to five clients and none chose to purchase them. Similarly, CCTV was demonstrated to 11 participants, but none expressed interest in the acquisition of the device. The likelihood of an individual recommended or acquiring LVDs (including HM, SM, around-the-neck embroidery magnifiers, spectacle mounted magnifiers, telescopes, and CCTV) was not statistically significantly different by age, gender, distance or near vision, cause of vision loss, or goal of rehabilitation (p > 0.05).
Following assessments by low vision advisors and optometrists, 80 of the 192 (42%) clients were recommended for orthoptics review regarding training in the use of optical and non-optical aids, lighting advice, visual field testing, and eccentric viewing training. Those younger than 70 years were less likely to require an orthoptic review than clients of any other age groups (p = 0.04). Nonetheless, 70 of 80 (88%) accepted the recommended referral. There was no significant difference in age, gender, distance or near vision, cause of VI, and rehabilitation goals between those who accepted orthoptic services and those who did not.
In contrast, with increasing age, clients were less likely to be referred to see an O&M instructor (p = 0.002). Of the 31 clients who were recommended to see an O&M instructor, 68% accepted the offer. Those who declined this service were more likely to be male (p = 0.004). However, this difference disappeared when adjusted for age.
The low vision advisors suggested OT assessments to 46 (24%) participants. Of these, 39 (85%) accepted the offer. There were no significant differences in age, gender, main cause of vision loss, distance and near vision, and goal of rehabilitation for those who were referred and those who had declined OT involvement.
In total, 61 participants (32%) were considered by the low vision advisors as requiring tertiary services such as either O&M or OT. However, only 46 (24%) participants accepted any of these tertiary rehabilitation services (Table 2). Of the 146 participants (76%) who did not attend any tertiary auxiliary services, only 6 required prescription of either high magnification HM (1/6) or SM (5/6). In other words, the remaining 73% (140/192) could have their needs adequately met by a secondary level LVC as defined by WHO.
This retrospective study of the services provided in an Australian LVC gives important insights into the current pattern of practice, the needs and the equipment of choice for those with low vision. Around the world, many countries (including Australia) have set up tertiary level LVCs to provide low vision rehabilitation. However, in many cases, a secondary level LVC is all that is required. Through this study, we are able to provide supporting data to estimate the proportion of people with low vision that can be adequately managed by a secondary level LVC.
Secondary level LVCs have been proposed by Vision 202012 to be an integral part of existing eye care services. As set out by WHO, the establishment of such services will require basic ophthalmic equipment such as a retinoscope, direct ophthalmoscope, trial lenses and frame, distance and near logMAR and contrast sensitivity charts and a small range of spectacle, handheld, stand, dome or bar magnifiers, monocular telescopes, and ultraviolet protection with luminous/selective transmission filters. Equipment such as color vision tests, hand disc perimetry, amsler grid, tangent screen, high magnification LVDs, and electronic magnifiers are not necessarily required. The estimated cost to equip an LVC at secondary level is U.S. $4000.13 In this study, the mismatch between the range of low vision service options available at a tertiary rehabilitation centers and choices in uptake of low vision services demonstrates that the needs of many could be met at a secondary level clinic.
Spectacles magnifiers and HMs were the most common types of low vision aids prescribed in this tertiary LVC and were usually of low to moderate magnification (92%). This high percentage of patients adequately managed by LVDs of up to ×5 magnification is consistent with findings in other studies. Leat and Rumney18 showed that 71.6% of patients were supplied with magnification of ≤ ×4 and around 80% were of ×5 or less magnification. Similarly, Wolffsohn and Cochrane19 found that the median magnification of LVDs prescribed was ×3.5 and the need of majority of the visually impaired population can be adequately met by stocking LVDs of up to ×7.
Of the 192 clients examined, 50 (24%) had additional assessment and training by an O&M instructor or OT to enhance their rehabilitation process. Including the six other clients requiring high magnification LVDS, in total, only 56 of the 192 (27%) participants used services at a tertiary level. In another words, it suggests that fewer than 30% of people with low vision require referrals to tertiary centers if secondary level LVCs are available. This is the first evidence-based result that we are aware of, against the WHO estimation/hypothesis that 50% of low vision population can be adequately managed by secondary level LVC. Future studies in nations with different low vision practices will be useful to compare with our results and to determine whether the results can be extended to other countries or communities.
If our study findings are representative of the demand in the wider community, a secondary level LVC would have the capacity to provide the majority of magnifiers and training that are helpful to people with VI. These magnifiers could be prescribed through an integrated service in preexisting eye care facilities. On-site basic training in magnifier use and low vision strategies could then be provided to the clients without further appointments. This would greatly facilitate access to low vision services by eliminating barriers such as transportation, distance, and lack of information.6,20
Secondary level LVCs can play an important role in bridging the gap between primary low vision care by community-based optometrists and the specialist tertiary low vision rehabilitation centers. Other than secondary level LVCs, other models of care have also been proposed to meet the challenge of providing easily accessible low vision services to an ageing population, especially in countries or areas where limited resources are available. One such model includes the outreach clinics in Northern Ireland.21 This involved a team of optometrists and rehabilitation workers attending communities requiring low vision care. However, this model of care required setting up a team of highly trained personnel and came at a cost to the already stretched healthcare resources. Another proposed model of care was an “open” LVC, such as that in Wales,18 where anyone can attend the clinic including those who self-referred. However, under this model of care, in addition to the problem of “inappropriate” referrals, patients will still require a second appointment and the need to travel again. When LVCs are established in conjunction with, and integrated into, ophthalmology clinics, departments, or hospitals, it can provide immediate and accessible low vision services, overcome barriers to service provision and allow rational allocation of valuable resources. It will also improve the flow of patients to tertiary vision rehabilitation.
Interestingly, in this study, some magnifiers were rarely demonstrated or recommended to clients. These included spectacle-mounted magnifiers—which offer magnification while allowing users to be hands-free; CCTV—which provide high magnification while maintaining a good working distance; and telescopes—which improve distance vision. There may be a multitude of reasons for this. It may be a reflection of the culture of common low vision practice, limitations of time, the needs and requirements of clients, costs of LVDs (because of lack of government funding), and ergonomics of LVDs. The reasons are beyond the scope of this article and further studies will be needed to ascertain the underlying reasons why such useful tools are often omitted in initial low vision assessments in our study clinic. However, this possible bias against the use of CCTV, telescopes, or spectacle-mounted spectacles may lead to an over-estimation of the proportion of LV population that are suitable for secondary level care.
A similar pattern of LVD use was also found in a separate study of the same center before 2 years19 and also other LVCs in United Kingdom.21–23 Despite having a higher percentage of SMs prescribed in these studies (ranging from 30 to 65%), possibly because of their recruitment of all attending patients rather than new patients only, they also have low propensities toward the use of spectacle-mounted magnifiers, telescopes, or CCTV. In India, where there were sparse low vision service deliveries, these LVDs were never prescribed.24 As pointed out by Crossland and Silver,23 spectacle-mounted telescopes and CCTV were less frequently prescribed, possibly because of financial burden and availability.
In comparison, the university-based LVC in Wales18,25 and the American-based LVC26 tend to have a larger percentage of spectacle-mounted magnifiers, telescopes, or CCTV prescribed. Leat and Rumney18 found that around 20% of patients older than 55 years were prescribed with spectacle-mounted magnifiers and 25% younger than 55 years with telescopes, whereas Scott et al.26 showed that as high as 59% of patients were supplied with spectacle-mounted magnifiers, 8.3% with handheld telescope, and 3.8% with electronic devices. There is an enormous variation in the types of LVDs prescribed at different LVCs around the world.
Because of different LV rehabilitation practices, we acknowledge that the result of our study may not be applicable or extendable to all low vision services. There may be different staffing structures, various levels of training and capabilities of ophthalmic personnel, diverse cultures of practice, unique assessment protocols, and different patterns or triggers for auxiliary referrals. All these factors may alter the proportion of the LV population that can be adequately managed at a secondary level.
In addition, there are a number of other limitations in this study. There is the potential bias in the results extrapolated from data relating to clients presenting to a tertiary level LVC. In particular, these clients may have had poor vision for a long period of time and had finally accepted the need for assistance. Thus, they may have required a higher level of care, including more frequent use of higher magnification LVDs and were more likely to avail themselves of auxiliary services such as OT and O&M than the total low vision population. However, given there were no secondary level LVCs present in Melbourne at the time of data collection, the demographics of the study subjects are likely to represent the spectrum of people with low vision, thus minimizing the selection bias present here. As the study only includes first time users of the LVC, there may be a propensity toward clients with milder visual impairment, leading to use of low-powered LVDs, less intensive rehabilitation or needs, and perhaps refusal of services because of denial or lack of acceptance.
Low vision rehabilitation is an important process in improving quality of life. The use of secondary level integrated low vision services would mean that people could potentially receive interventions at an earlier stage.14,15 Early interventions and improvement in quality of life may also reduce the need for intense rehabilitation in the future, thereby further alleviating the burden on tertiary level low vision care. These predictions of the capabilities of secondary level LVCs will need to be confirmed by evaluation of such services, such as those currently being established at Royal Victorian Eye and Ear Hospital.
The establishment of secondary level LVCs as part of existing eye care facilities would improve access to low vision care and resources and could meet the needs of up to 70% of people with low vision. By doing so, these secondary level LVCs could do much to reduce the impact of VI and improve vision-related quality of life in both developing and developed countries.
We thank Jennifer Hassell and the staff of Vision Australia for their assistance in the collection of data.
Elaine Y. H. Wong
Centre for Eye Research Australia
University of Melbourne
32 Gisborne Street
East Melbourne, VIC 3002