C L I N I C A L
A N D
E X P E R I M E N T A L
OPTOMETRY REVIEW
Clinical outcomes following the dispensing of ready-made and recycled spectacles: A systematic literature review Clin Exp Optom 2014; 97: 225–233 Matthew G Pearce OD MPH FAAO Office of Public Health Studies, University of Hawaii at Manoa, Honolulu, HI, USA E-mail: [email protected]
Submitted: 12 July 2013 Revised: 3 October 2013 Accepted for publication: 7 October 2013
DOI:10.1111/cxo.12126 Uncorrected refractive error is the leading cause of global visual impairment. Given resource constraints in developing countries, the gold standard method of refractive error correction, custom-made spectacles, is unlikely to be available for some time. Therefore, ready-made and recycled spectacles are in wide use in the developing world. To ensure that refractive error interventions are successful, it is important that only appropriate modes of refractive error correction are used. As a basis for policy development, a systematic literature review was conducted of interventional studies analysing visual function, patient satisfaction and continued use outcomes of ready-made and recycled spectacles dispensed to individuals in developing countries with refractive errors or presbyopia. PubMed and CINAHL were searched by MESH terms and keywords related to ready-made and recycled spectacle interventions, yielding 185 non-duplicated papers. After applying exclusion criteria, eight papers describing seven studies of clinical outcomes of dispensing ready-made spectacles were retained for analysis. The two randomised controlled trials and five non-experimental studies suggest that ready-made spectacles can provide sufficient visual function for a large portion of the world’s population with refractive error, including those with astigmatism and/or anisometropia. The follow-up period for many of the studies was too short to confidently comment on patient satisfaction and continued-use outcomes. No studies were found that met inclusion criteria and discussed recycled spectacles. The literature also notes concerns about quality and cost effectiveness of recycled spectacles, as well as their tendency to increase developing countries’ reliance on outside sources of help. In light of the findings, the dispensing of ready-made spectacles should be favoured over the dispensing of recycled spectacles in developing countries.
Key words: public health, ready-made spectacles, recycled spectacles, refractive errors Uncorrected refractive error, affecting 153 million people, is the leading cause of visual impairment and a significant cause of blindness in the developing world.1 Uncorrected presbyopia is estimated to cause visual disability in a further 410 million people.2 Visual impairment and presbyopia have profound effects on quality of life,3 economic productivity4 and physical activity.5 While there is little disagreement on the need to train and support local eye-care professionals to provide high-quality refractive care,6,7 there is some debate on what constitutes appropriate refractive error correction in developing countries. Although refractive surgery and contact lenses can successfully correct refractive error, their cost and potential complications limit their usefulness in the developing world.8 Generally, spectacles are less expensive, carry no risk of complication and are the treatment of choice.
Custom-made spectacles are the gold standard in spectacle correction; however, due to financial and infrastructural challenges, it is difficult to set up sufficient numbers of optical laboratories and appropriate distribution networks for custommade spectacles in the developing world. Where custom-made spectacles are available, they are often unaffordable for those of lower socio-economic status. Ready-made and recycled spectacles are used as refractive correction when custommade spectacles are unavailable or unaffordable in the developing world. Ready-made spectacles are mass produced in selected powers with equal spherical correction in each eye and can be purchased in bulk for as little as US$0.45 from distributors in China.9 Recycled spectacles are generally collected, cleaned and sorted in developed countries and then sent to clinics in the developing
© 2014 The Author Clinical and Experimental Optometry © 2014 Optometrists Association Australia
world or brought by visiting eye-care teams. The use of recycled spectacles has been discouraged by public health eye-care professionals, as well as the World Health Organization Refractive Error Working Group, due to poor quality,10 cost,11 the fact that many eye-care providers and users in the developing world do not want them,12 the difficulty of finding a suitable prescriptive match10 and their creation of a reliance on outside sources of spectacles;8 however, many organisations still use them.13,14 Public health programs strive to provide the best treatment in the most economically efficient way that meets the greatest need in the community. To help inform refractive error programs, a systematic literature review, following PRISMA guidelines15 was conducted of interventional studies analysing visual function, patient satisfaction and continued use outcomes of ready-made and Clinical and Experimental Optometry 97.3 May 2014
225
Ready-made spectacles Pearce
Uncorrected refractive error Equitably accessible refractive care
Trained refractionist
Appropriate infrastructure
Quality refraction
Spectacles
Improved visual function
Satisfaction
Continued use
Successful refractive error correction Figure 1. Conceptual framework. Items higher in the conceptual framework are required in order to reach the lower levels. Items on the same horizontal line are all required in order to reach the lower level. For example, equitably accessible refractive care needs to be available so that a patient can be refracted before they can be determined to have successful refractive error correction. However, prior to having successful refractive error correction, care must be provided by a trained refractionist and occur with appropriate infrastructure. This framework does not account for all of the inputs necessary at higher levels. For example, to have a trained refractionist, a training institution, curriculum, mentorship, professional support, a job description et cetera, are required.
recycled spectacles dispensed to patients with refractive errors or presbyopia in developing countries.
METHODS A conceptual framework on inputs required for successful refractive error correction was developed (Figure 1). The conceptual framework proposes that successful spectacle correction requires that patients experience an improvement in their visual function, that they are satisfied with the spectacles dispensed and that they continue using the dispensed corrective lenses. If visual function is not improved with spectacles, this is a low-value treatment16 and wastes Clinical and Experimental Optometry 97.3 May 2014
226
scarce resources. If patients are dissatisfied with their spectacles, for visual functional, cosmetic or physical comfort reasons, they are unlikely to continue using their spectacles and the intervention will be of limited benefit and may cause patient frustration. If patients discontinue use of their spectacles, due to spectacle breakage, teasing or other reasons the success of the intervention will be limited. Published clinical outcome studies on the dispensing of ready-made and recycled spectacles in developing countries were identified via searches of PubMed and CINAHL. In addition to database searches, references of articles were examined to identify further papers. These databases were last searched on May 21, 2013.
Medical subject headings related to clinical outcomes of dispensing ready-made and recycled spectacles in developing countries were identified and entered in combination with select keywords in these databases (Table 1). Only papers published in peer-reviewed journals were considered for inclusion. No time bounds were placed on the search, although the search was limited to papers written in English and to interventions occurring in the developing world (countries with a gross national income up to US$11,905 in 2010).17 Included papers could be of any study design, although they had to report on a clinical intervention. Refractive error was defined as myopia of -1.00 DS or more, hyperopia of +1.00 DS or more or astigmatism greater than 0.75 DC, which is a modified World Health Organization (WHO) definition8 based on optometric prescribing patterns.18 This amount of uncorrected refractive error is likely to interfere with one or more activities of daily living. Presbyopia was defined as an age-related functional deficit in near vision, amenable to correction via spectacles. Refractive error measurement could be via subjective refraction, retinoscopy by a trained refractionist or cyclopegic autorefraction.8,19 To be included, an article had to report one or more of three outcomes: 1. visual function prior to and after; readymade or recycled spectacle correction 2. patient satisfaction with the spectacles dispensed and 3. use of spectacles at some point following dispensing. The study population could include any age group with refractive error or presbyopia. Studies that used self-refraction and selfadjusting spectacles were excluded due to their limited use. The titles of identified papers were scanned and irrelevant papers excluded. The abstracts of remaining papers were then read and irrelevant papers excluded. The remaining papers were read in detail, with some being excluded during this reading. Those papers that met all inclusion criteria and did not meet any exclusion criteria were analysed. Analysis included a quality appraisal on a 10-point scale (10 being the highest quality study) using a modified version of the Critical Appraisal Skills Programme’s checklists.20 As no study describing clinical outcomes following the dispensing of recycled © 2014 The Author
Clinical and Experimental Optometry © 2014 Optometrists Association Australia
Ready-made spectacles Pearce
Number Number of papers of papers found— found— Pubmed CINAHL Eyeglasses
and Refractive error
and Developing countries
33
3
Eyeglasses
and Presbyopia
and Developing countries
11
0 1
Eyeglasses
and Visual acuity
and Developing countries
21
Eyeglasses
and Patient satisfaction
and Developing countries
2
0
Eyeglasses
and Utilisation
and Developing countries
8
0
Eyeglasses
and Patient acceptance of healthcare
and Developing countries
5
0
Eyeglasses
and Disposable equipment
Eyeglasses
and Equipment reuse
Eyeglasses
and Patient compliance
Ready made or spectacles
Ready made eyeglasses
Recycled spectacles
or
Recycled eyeglasses
Used spectacles
or
Used eyeglasses
or
Readymade spectacles or Readymade or Ready-made or Ready-made eyeglasses eyeglasses spectacles
and Developing countries
11
0
3
0
73
9
32
1
7
0
69
2
Table 1. Search terms and number of papers found
spectacles met all of the inclusion criteria, a secondary analysis on three excluded studies that described interventions with recycled spectacles was conducted. RESULTS A total of 291 papers were found using the search criteria described above. No additional papers were found through citation mining, although an additional paper was identified via consultation with researchers in this area of study. After removing duplicates, 185 articles remained. Following all exclusions (Figure 2), eight papers remained (Table 2), all of which were of moderate to high quality. Two papers reported different results from the same study population and are combined in this analysis.21,22 The eight papers reported on seven studies, conducted in five countries (China, Nicaragua, India, Tanzania [two studies] and Thailand [two studies]). All seven studies considered outcomes related to ready-made spectacles.21–28 No study meeting the inclusion criteria and looking at outcomes from the dispensing of recycled spectacles was found. Five of the seven studies used a non-experimental one-group, pre-test, post-test design23–26,28 and the other two studies (three papers)
used a randomised controlled trial (RCT) design.21,22,27 Outcomes from each study were extracted and grouped into general categories (Table 3). The general categories were then grouped into the three requirements for successful spectacle correction from the conceptual framework (Table 4). The two randomised controlled trials compared ready-made and custom-made spectacles for distance refractive errors.21,22,27 Both studies considered outcomes from each of the three categories necessary for successful refractive error correction. Brady and colleagues21 and Keay and colleagues22 studied a population of adults (18 to 45 years old) in India, while Zeng and colleagues27 studied a population of 12- to 15-year-old students in China. One limitation to the two randomised controlled trials was that they did not use true ready-made spectacles. Rather than ordering mass-produced readymade spectacles from a distributor or factory, they ordered spectacles with spherical power and common interpupillary distances from the same optical laboratory that was producing the custom-made spectacles used in the study. While this was likely done as a means of keeping study personnel masked to treatment type, it may not reflect what would occur if mass-produced ready-
© 2014 The Author Clinical and Experimental Optometry © 2014 Optometrists Association Australia
made spectacles were used due to potential differences in spectacle durability and quality. The remaining interventions23–26,28 used non-experimental designs. Three of these studies focussed on presbyopia,23–25 with two others considering presbyopia and refractive error.26,28 The study of Patel and colleagues in Tanzania25 was the only nonexperimental study that reported outcomes across the three key areas. The studies of Laviers and colleagues24 in another region of Tanzania and Hookway, Fuhr and Fazier28 in Nicaragua each discussed two key areas. Imsuwan and Malaithong23 and Vincent and colleagues,26 working in different regions of Thailand, each reported on only one key area.
Visual function Visual function was measured in six studies and was the most common outcome reported, demonstrating improved visual acuity from baseline with spectacle correction in all studies that considered it as an outcome measure, including the two randomised controlled trials.21–25,27,28 Similarly, visual function and quality of life were improved with ready-made spectacles.21,22,24,25,28 Visual function outcomes were similar to those for custom-made spectacles Clinical and Experimental Optometry 97.3 May 2014
227
Ready-made spectacles Pearce
Records identified through database search (n = 291)
Additional records identified through other sources (n = 1)
Records after duplicates (107) removed (n = 185) Records excluded by title (n = 109) Records screened (n = 185)
Topic was not of interest (n = 107) Study conducted in developed world (n = 1) Study used adjustable spectacles (n = 1)
Articles excluded by abstract (n = 40) Abstracts assessed for eligibility (n = 76)
Full-text articles assessed for eligibility (n = 36)
Studies included in primary analysis (n = 8)
Study did not include an intervention (n = 22) Topic was not of interest (n = 7) Study was conducted in developed world (n = 4) Study used CMS (n = 3) Study outcome was not of interest (n = 2) Intervention used was not of interest (n = 1) Study used non-cycloplegic autorefraction (n = 1)
Full-text articles excluded (n = 28) Editorial or letter (n = 12) Study did not include an intervention (n = 6) Study used CMS (n = 5) Analysis was not separated by type of spectacles (n = 2) Study conducted in the developed world (n = 1)* Study used non-cycloplegic autorefraction (n = 2)*
*Studies included in secondary analysis (n = 3)
Patient selection for ready-made spectacles
Figure 2. Flow diagram of study selection
in both of the randomised controlled trials.21,22,27
Patient satisfaction Patient satisfaction outcomes were considered in five studies.21,22,24,25,27,28 Patient retention of spectacles was used as one measure of patient satisfaction; however, subject follow-up was not consistent across studies. Indian subjects were assessed at one month, with 95 per cent of all subjects found to have retained their spectacles.21,22 Subjects in the Zanzibar, Tanzania study were assessed at six months and 93.6 per cent retained their presbyopic ready-made spectacles.24 In a separate study, in a different part of Tanzania, after two months 97 per cent of subjects were found to have retained their readymade spectacles for presbyopia.25 While retention of spectacles served as a proxy measure of satisfaction, it should be noted that some patients retained spectacles but did not use them.25 Clinical and Experimental Optometry 97.3 May 2014
228
Keay and colleagues22 reported that 90.2 per cent of subjects in Dehli, India planned to continue to wear their ready-made spectacles. Those who did not intend to continue to use their ready-made spectacles were more likely to have astigmatism of 2.00 DC or more or anisometropia of 1.00 DS or more. In Guangzhou, China, Zeng and colleagues27 measured self-reported spectacle use and whether the patients had their spectacles on hand at follow-up. The authors found that 94.3 per cent of subjects reported using their ready-made spectacles (compared to 92.2 per cent of subjects with custom-made spectacles) and that 46.9 per cent had their ready-made spectacles on hand (compared to 51.5 per cent of subjects with custom-made spectacles). In Kongwa town, Tanzania, 92.2 per cent of subjects reported using their near spectacles in the preceding month.25 Vincent and colleagues26 found decreasing continued use of ready-made spectacles in a Burmese refugee population in Thailand, with about 74 per cent reporting that they were using them at six months and 56 per cent using them after 12 months. The primary reason for non-use was that the frame or lenses were broken, although a large percentage of discontinuations were due to vision-related complaints.
Three studies looked at patient-reported satisfaction via five-point Likert scales.21,22,24,28 Hookway, Fuhr and Fazier28 and Brady and colleagues21 found that patients had increased satisfaction with their vision immediately and one month, respectively after receiving their ready-made spectacles. Laviers and colleagues24 found that patients were still satisfied two months after having their spectacles dispensed. Zeng and colleagues27 asked subjects to place a value on their spectacles. Almost 90 per cent of subjects receiving ready-made spectacles rated their spectacles as of moderate value to their most valued possession. There was no significant difference in value placed on custom-made spectacles.
While Zeng and colleagues,27 Imsuwan and Malaithong23 and Laviers and colleagues24 limited providing ready-made spectacles to patients they pre-selected to be good candidates, other studies did not. Most notably the randomised controlled trial conducted in India21,22 did not find refractive cut-offs that would be useful as exclusionary criteria for the dispensing of ready-made spectacles. Rather, they suggested that because readymade spectacles can be dispensed at the time of refraction, in situations where custom-made spectacles are not available or are unaffordable, they can be offered to the patient for an in-clinic trial. If the readymade spectacles are not well tolerated or if they produce poor visual outcomes, the patient should then be switched to custommade spectacles.
Continued use Continued use was measured as subjectreported planned use, as well as actual use. Actual use was reported by the subject or observed by members of the research team.
Recycled spectacles If the inclusion criteria in this literature review were relaxed to allow for nonideal methods of refraction, definitions of © 2014 The Author
Clinical and Experimental Optometry © 2014 Optometrists Association Australia
Non-experimental
Non-experimental
Non-experimental
Non-experimental
Non-experimental
Randomised controlled trial
Hookway, Fuhr and Frazier28
Imsuwan and Malaithong23
Laviers and colleagues24
Patel and colleagues25
Vincent and colleagues26
Zeng and colleagues27
© 2014 The Author
Clinical and Experimental Optometry © 2014 Optometrists Association Australia
10.0
8.9
A retrospective study on all patients with visual impairment due to refractive error and/or presbyopia who were older than 34 years and presented to a February, 2010 outreach clinic. Aged 35 years or older with best corrected visual acuity 6/12 or better, and distance visual acuity 6/60 or better. Subject must have less than 1 D of astigmatism, no previous ocular surgery or injury, and no ocular pathology. Aged older than 40 years with a presenting or corrected distance visual acuity of 6/18 or better in one or both eyes. Aged ≥40 years old with distance VA 6/18.9 or better. Patients who received spectacles 6 or 12 months prior to the study and lived within a selected refugee camp. VA ≤ 6/12 and ≥1.00 D uncorrected spherical equivalent refractive error or requiring a change in habitual prescription ≥1.00 D. Patients must have
A N D
E X P E R I M E N T A L
OPTOMETRY REVIEW
Clinical outcomes following the dispensing of ready-made and recycled spectacles: A systematic literature review Clin Exp Optom 2014; 97: 225–233 Matthew G Pearce OD MPH FAAO Office of Public Health Studies, University of Hawaii at Manoa, Honolulu, HI, USA E-mail: [email protected]
Submitted: 12 July 2013 Revised: 3 October 2013 Accepted for publication: 7 October 2013
DOI:10.1111/cxo.12126 Uncorrected refractive error is the leading cause of global visual impairment. Given resource constraints in developing countries, the gold standard method of refractive error correction, custom-made spectacles, is unlikely to be available for some time. Therefore, ready-made and recycled spectacles are in wide use in the developing world. To ensure that refractive error interventions are successful, it is important that only appropriate modes of refractive error correction are used. As a basis for policy development, a systematic literature review was conducted of interventional studies analysing visual function, patient satisfaction and continued use outcomes of ready-made and recycled spectacles dispensed to individuals in developing countries with refractive errors or presbyopia. PubMed and CINAHL were searched by MESH terms and keywords related to ready-made and recycled spectacle interventions, yielding 185 non-duplicated papers. After applying exclusion criteria, eight papers describing seven studies of clinical outcomes of dispensing ready-made spectacles were retained for analysis. The two randomised controlled trials and five non-experimental studies suggest that ready-made spectacles can provide sufficient visual function for a large portion of the world’s population with refractive error, including those with astigmatism and/or anisometropia. The follow-up period for many of the studies was too short to confidently comment on patient satisfaction and continued-use outcomes. No studies were found that met inclusion criteria and discussed recycled spectacles. The literature also notes concerns about quality and cost effectiveness of recycled spectacles, as well as their tendency to increase developing countries’ reliance on outside sources of help. In light of the findings, the dispensing of ready-made spectacles should be favoured over the dispensing of recycled spectacles in developing countries.
Key words: public health, ready-made spectacles, recycled spectacles, refractive errors Uncorrected refractive error, affecting 153 million people, is the leading cause of visual impairment and a significant cause of blindness in the developing world.1 Uncorrected presbyopia is estimated to cause visual disability in a further 410 million people.2 Visual impairment and presbyopia have profound effects on quality of life,3 economic productivity4 and physical activity.5 While there is little disagreement on the need to train and support local eye-care professionals to provide high-quality refractive care,6,7 there is some debate on what constitutes appropriate refractive error correction in developing countries. Although refractive surgery and contact lenses can successfully correct refractive error, their cost and potential complications limit their usefulness in the developing world.8 Generally, spectacles are less expensive, carry no risk of complication and are the treatment of choice.
Custom-made spectacles are the gold standard in spectacle correction; however, due to financial and infrastructural challenges, it is difficult to set up sufficient numbers of optical laboratories and appropriate distribution networks for custommade spectacles in the developing world. Where custom-made spectacles are available, they are often unaffordable for those of lower socio-economic status. Ready-made and recycled spectacles are used as refractive correction when custommade spectacles are unavailable or unaffordable in the developing world. Ready-made spectacles are mass produced in selected powers with equal spherical correction in each eye and can be purchased in bulk for as little as US$0.45 from distributors in China.9 Recycled spectacles are generally collected, cleaned and sorted in developed countries and then sent to clinics in the developing
© 2014 The Author Clinical and Experimental Optometry © 2014 Optometrists Association Australia
world or brought by visiting eye-care teams. The use of recycled spectacles has been discouraged by public health eye-care professionals, as well as the World Health Organization Refractive Error Working Group, due to poor quality,10 cost,11 the fact that many eye-care providers and users in the developing world do not want them,12 the difficulty of finding a suitable prescriptive match10 and their creation of a reliance on outside sources of spectacles;8 however, many organisations still use them.13,14 Public health programs strive to provide the best treatment in the most economically efficient way that meets the greatest need in the community. To help inform refractive error programs, a systematic literature review, following PRISMA guidelines15 was conducted of interventional studies analysing visual function, patient satisfaction and continued use outcomes of ready-made and Clinical and Experimental Optometry 97.3 May 2014
225
Ready-made spectacles Pearce
Uncorrected refractive error Equitably accessible refractive care
Trained refractionist
Appropriate infrastructure
Quality refraction
Spectacles
Improved visual function
Satisfaction
Continued use
Successful refractive error correction Figure 1. Conceptual framework. Items higher in the conceptual framework are required in order to reach the lower levels. Items on the same horizontal line are all required in order to reach the lower level. For example, equitably accessible refractive care needs to be available so that a patient can be refracted before they can be determined to have successful refractive error correction. However, prior to having successful refractive error correction, care must be provided by a trained refractionist and occur with appropriate infrastructure. This framework does not account for all of the inputs necessary at higher levels. For example, to have a trained refractionist, a training institution, curriculum, mentorship, professional support, a job description et cetera, are required.
recycled spectacles dispensed to patients with refractive errors or presbyopia in developing countries.
METHODS A conceptual framework on inputs required for successful refractive error correction was developed (Figure 1). The conceptual framework proposes that successful spectacle correction requires that patients experience an improvement in their visual function, that they are satisfied with the spectacles dispensed and that they continue using the dispensed corrective lenses. If visual function is not improved with spectacles, this is a low-value treatment16 and wastes Clinical and Experimental Optometry 97.3 May 2014
226
scarce resources. If patients are dissatisfied with their spectacles, for visual functional, cosmetic or physical comfort reasons, they are unlikely to continue using their spectacles and the intervention will be of limited benefit and may cause patient frustration. If patients discontinue use of their spectacles, due to spectacle breakage, teasing or other reasons the success of the intervention will be limited. Published clinical outcome studies on the dispensing of ready-made and recycled spectacles in developing countries were identified via searches of PubMed and CINAHL. In addition to database searches, references of articles were examined to identify further papers. These databases were last searched on May 21, 2013.
Medical subject headings related to clinical outcomes of dispensing ready-made and recycled spectacles in developing countries were identified and entered in combination with select keywords in these databases (Table 1). Only papers published in peer-reviewed journals were considered for inclusion. No time bounds were placed on the search, although the search was limited to papers written in English and to interventions occurring in the developing world (countries with a gross national income up to US$11,905 in 2010).17 Included papers could be of any study design, although they had to report on a clinical intervention. Refractive error was defined as myopia of -1.00 DS or more, hyperopia of +1.00 DS or more or astigmatism greater than 0.75 DC, which is a modified World Health Organization (WHO) definition8 based on optometric prescribing patterns.18 This amount of uncorrected refractive error is likely to interfere with one or more activities of daily living. Presbyopia was defined as an age-related functional deficit in near vision, amenable to correction via spectacles. Refractive error measurement could be via subjective refraction, retinoscopy by a trained refractionist or cyclopegic autorefraction.8,19 To be included, an article had to report one or more of three outcomes: 1. visual function prior to and after; readymade or recycled spectacle correction 2. patient satisfaction with the spectacles dispensed and 3. use of spectacles at some point following dispensing. The study population could include any age group with refractive error or presbyopia. Studies that used self-refraction and selfadjusting spectacles were excluded due to their limited use. The titles of identified papers were scanned and irrelevant papers excluded. The abstracts of remaining papers were then read and irrelevant papers excluded. The remaining papers were read in detail, with some being excluded during this reading. Those papers that met all inclusion criteria and did not meet any exclusion criteria were analysed. Analysis included a quality appraisal on a 10-point scale (10 being the highest quality study) using a modified version of the Critical Appraisal Skills Programme’s checklists.20 As no study describing clinical outcomes following the dispensing of recycled © 2014 The Author
Clinical and Experimental Optometry © 2014 Optometrists Association Australia
Ready-made spectacles Pearce
Number Number of papers of papers found— found— Pubmed CINAHL Eyeglasses
and Refractive error
and Developing countries
33
3
Eyeglasses
and Presbyopia
and Developing countries
11
0 1
Eyeglasses
and Visual acuity
and Developing countries
21
Eyeglasses
and Patient satisfaction
and Developing countries
2
0
Eyeglasses
and Utilisation
and Developing countries
8
0
Eyeglasses
and Patient acceptance of healthcare
and Developing countries
5
0
Eyeglasses
and Disposable equipment
Eyeglasses
and Equipment reuse
Eyeglasses
and Patient compliance
Ready made or spectacles
Ready made eyeglasses
Recycled spectacles
or
Recycled eyeglasses
Used spectacles
or
Used eyeglasses
or
Readymade spectacles or Readymade or Ready-made or Ready-made eyeglasses eyeglasses spectacles
and Developing countries
11
0
3
0
73
9
32
1
7
0
69
2
Table 1. Search terms and number of papers found
spectacles met all of the inclusion criteria, a secondary analysis on three excluded studies that described interventions with recycled spectacles was conducted. RESULTS A total of 291 papers were found using the search criteria described above. No additional papers were found through citation mining, although an additional paper was identified via consultation with researchers in this area of study. After removing duplicates, 185 articles remained. Following all exclusions (Figure 2), eight papers remained (Table 2), all of which were of moderate to high quality. Two papers reported different results from the same study population and are combined in this analysis.21,22 The eight papers reported on seven studies, conducted in five countries (China, Nicaragua, India, Tanzania [two studies] and Thailand [two studies]). All seven studies considered outcomes related to ready-made spectacles.21–28 No study meeting the inclusion criteria and looking at outcomes from the dispensing of recycled spectacles was found. Five of the seven studies used a non-experimental one-group, pre-test, post-test design23–26,28 and the other two studies (three papers)
used a randomised controlled trial (RCT) design.21,22,27 Outcomes from each study were extracted and grouped into general categories (Table 3). The general categories were then grouped into the three requirements for successful spectacle correction from the conceptual framework (Table 4). The two randomised controlled trials compared ready-made and custom-made spectacles for distance refractive errors.21,22,27 Both studies considered outcomes from each of the three categories necessary for successful refractive error correction. Brady and colleagues21 and Keay and colleagues22 studied a population of adults (18 to 45 years old) in India, while Zeng and colleagues27 studied a population of 12- to 15-year-old students in China. One limitation to the two randomised controlled trials was that they did not use true ready-made spectacles. Rather than ordering mass-produced readymade spectacles from a distributor or factory, they ordered spectacles with spherical power and common interpupillary distances from the same optical laboratory that was producing the custom-made spectacles used in the study. While this was likely done as a means of keeping study personnel masked to treatment type, it may not reflect what would occur if mass-produced ready-
© 2014 The Author Clinical and Experimental Optometry © 2014 Optometrists Association Australia
made spectacles were used due to potential differences in spectacle durability and quality. The remaining interventions23–26,28 used non-experimental designs. Three of these studies focussed on presbyopia,23–25 with two others considering presbyopia and refractive error.26,28 The study of Patel and colleagues in Tanzania25 was the only nonexperimental study that reported outcomes across the three key areas. The studies of Laviers and colleagues24 in another region of Tanzania and Hookway, Fuhr and Fazier28 in Nicaragua each discussed two key areas. Imsuwan and Malaithong23 and Vincent and colleagues,26 working in different regions of Thailand, each reported on only one key area.
Visual function Visual function was measured in six studies and was the most common outcome reported, demonstrating improved visual acuity from baseline with spectacle correction in all studies that considered it as an outcome measure, including the two randomised controlled trials.21–25,27,28 Similarly, visual function and quality of life were improved with ready-made spectacles.21,22,24,25,28 Visual function outcomes were similar to those for custom-made spectacles Clinical and Experimental Optometry 97.3 May 2014
227
Ready-made spectacles Pearce
Records identified through database search (n = 291)
Additional records identified through other sources (n = 1)
Records after duplicates (107) removed (n = 185) Records excluded by title (n = 109) Records screened (n = 185)
Topic was not of interest (n = 107) Study conducted in developed world (n = 1) Study used adjustable spectacles (n = 1)
Articles excluded by abstract (n = 40) Abstracts assessed for eligibility (n = 76)
Full-text articles assessed for eligibility (n = 36)
Studies included in primary analysis (n = 8)
Study did not include an intervention (n = 22) Topic was not of interest (n = 7) Study was conducted in developed world (n = 4) Study used CMS (n = 3) Study outcome was not of interest (n = 2) Intervention used was not of interest (n = 1) Study used non-cycloplegic autorefraction (n = 1)
Full-text articles excluded (n = 28) Editorial or letter (n = 12) Study did not include an intervention (n = 6) Study used CMS (n = 5) Analysis was not separated by type of spectacles (n = 2) Study conducted in the developed world (n = 1)* Study used non-cycloplegic autorefraction (n = 2)*
*Studies included in secondary analysis (n = 3)
Patient selection for ready-made spectacles
Figure 2. Flow diagram of study selection
in both of the randomised controlled trials.21,22,27
Patient satisfaction Patient satisfaction outcomes were considered in five studies.21,22,24,25,27,28 Patient retention of spectacles was used as one measure of patient satisfaction; however, subject follow-up was not consistent across studies. Indian subjects were assessed at one month, with 95 per cent of all subjects found to have retained their spectacles.21,22 Subjects in the Zanzibar, Tanzania study were assessed at six months and 93.6 per cent retained their presbyopic ready-made spectacles.24 In a separate study, in a different part of Tanzania, after two months 97 per cent of subjects were found to have retained their readymade spectacles for presbyopia.25 While retention of spectacles served as a proxy measure of satisfaction, it should be noted that some patients retained spectacles but did not use them.25 Clinical and Experimental Optometry 97.3 May 2014
228
Keay and colleagues22 reported that 90.2 per cent of subjects in Dehli, India planned to continue to wear their ready-made spectacles. Those who did not intend to continue to use their ready-made spectacles were more likely to have astigmatism of 2.00 DC or more or anisometropia of 1.00 DS or more. In Guangzhou, China, Zeng and colleagues27 measured self-reported spectacle use and whether the patients had their spectacles on hand at follow-up. The authors found that 94.3 per cent of subjects reported using their ready-made spectacles (compared to 92.2 per cent of subjects with custom-made spectacles) and that 46.9 per cent had their ready-made spectacles on hand (compared to 51.5 per cent of subjects with custom-made spectacles). In Kongwa town, Tanzania, 92.2 per cent of subjects reported using their near spectacles in the preceding month.25 Vincent and colleagues26 found decreasing continued use of ready-made spectacles in a Burmese refugee population in Thailand, with about 74 per cent reporting that they were using them at six months and 56 per cent using them after 12 months. The primary reason for non-use was that the frame or lenses were broken, although a large percentage of discontinuations were due to vision-related complaints.
Three studies looked at patient-reported satisfaction via five-point Likert scales.21,22,24,28 Hookway, Fuhr and Fazier28 and Brady and colleagues21 found that patients had increased satisfaction with their vision immediately and one month, respectively after receiving their ready-made spectacles. Laviers and colleagues24 found that patients were still satisfied two months after having their spectacles dispensed. Zeng and colleagues27 asked subjects to place a value on their spectacles. Almost 90 per cent of subjects receiving ready-made spectacles rated their spectacles as of moderate value to their most valued possession. There was no significant difference in value placed on custom-made spectacles.
While Zeng and colleagues,27 Imsuwan and Malaithong23 and Laviers and colleagues24 limited providing ready-made spectacles to patients they pre-selected to be good candidates, other studies did not. Most notably the randomised controlled trial conducted in India21,22 did not find refractive cut-offs that would be useful as exclusionary criteria for the dispensing of ready-made spectacles. Rather, they suggested that because readymade spectacles can be dispensed at the time of refraction, in situations where custom-made spectacles are not available or are unaffordable, they can be offered to the patient for an in-clinic trial. If the readymade spectacles are not well tolerated or if they produce poor visual outcomes, the patient should then be switched to custommade spectacles.
Continued use Continued use was measured as subjectreported planned use, as well as actual use. Actual use was reported by the subject or observed by members of the research team.
Recycled spectacles If the inclusion criteria in this literature review were relaxed to allow for nonideal methods of refraction, definitions of © 2014 The Author
Clinical and Experimental Optometry © 2014 Optometrists Association Australia
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Randomised controlled trial
Hookway, Fuhr and Frazier28
Imsuwan and Malaithong23
Laviers and colleagues24
Patel and colleagues25
Vincent and colleagues26
Zeng and colleagues27
© 2014 The Author
Clinical and Experimental Optometry © 2014 Optometrists Association Australia
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A retrospective study on all patients with visual impairment due to refractive error and/or presbyopia who were older than 34 years and presented to a February, 2010 outreach clinic. Aged 35 years or older with best corrected visual acuity 6/12 or better, and distance visual acuity 6/60 or better. Subject must have less than 1 D of astigmatism, no previous ocular surgery or injury, and no ocular pathology. Aged older than 40 years with a presenting or corrected distance visual acuity of 6/18 or better in one or both eyes. Aged ≥40 years old with distance VA 6/18.9 or better. Patients who received spectacles 6 or 12 months prior to the study and lived within a selected refugee camp. VA ≤ 6/12 and ≥1.00 D uncorrected spherical equivalent refractive error or requiring a change in habitual prescription ≥1.00 D. Patients must have
