Topical review: Task shifting and the recruitment and retention of eye health workers in underserved areas

Many populations experience difficulty accessing eye care, especially in rural areas. Implementing workforce recruitment and retention strategies, as well as task shifting through widening scope of practice, can improve eye care accessibility. This article provides novel evidence on the compatibility of these strategies aimed at enhancing ophthalmic workforce recruitment, retention, and efficacy.

PURPOSE

The global burden of blindness is unequally distributed, affects rural areas more, and is frequently associated with limited access to eye care. The World Health Organization has specified both task shifting and increasing human resources for eye health as instruments to improve access to eye care in underserved areas. However, it is uncertain whether these two instruments are sufficiently compatible to provide positive synergic effects. To address this uncertainty, we conducted a structured literature review and synthesized relevant evidence relating to task shifting, workforce recruitment, retention, and eye care. Twenty-three studies from across the globe were analyzed and grouped into three categories: studies exploring recruitment and retention in human resources for eye health in general, studies discussing the relationship between task shifting and recruitment or retention of health workers in general, and studies specifically discussing task shifting and recruitment or retention in eye care workers.

FINDINGS

Our findings demonstrate that incentives are effective for initiating task shifting and improving recruitment and retention in rural areas with a stronger effect noted in midlevel eye care professionals and trainees. Incentives can take various forms, e.g., financial and nonfinancial. The consideration of context-specific motivational factors is essential when designing strategies to facilitate task shifting and to improve recruitment and retention.

The role of peripheral ocular length and peripheral corneal radius of curvature in determining refractive error

PURPOSE

The purpose of this study was to extend the knowledge of peripheral biometric component and its relationship to refractive status in healthy individuals by determining the correlation between peripheral ocular length to peripheral corneal radius ratio and the refractive error.

METHODS

This prospective study was conducted on thirty-three healthy adult participants. Refractive error was assessed objectively and subjectively and recorded as the mean spherical equivalent. Central and peripheral ocular lengths at 30° were assessed using partial coherence interferometry under dilation with 1% tropicamide. Central and peripheral corneal radius of curvature was assessed using Scheimpflug topography. Peripheral ocular lengths at 30° were paired with peripheral corneal curvatures at the incident points of the IOLMaster beam (3.8mm away from corneal apex) superiorly, inferiorly, temporally and nasally to calculate the peripheral ocular length-peripheral corneal radius ratio. Descriptive statistics were used to describe the distribution and spread of the data. Pearson's correlation analysis was used to present the association between biometric and refractive variables.

RESULTS

Refractive error was negatively correlated with the axial length-central corneal radius ratio (r=-0.91; p<0.001) and with 30° peripheral ocular length-peripheral corneal radius ratio in all four meridians (r≤-0.76; p<0.001). The strength of the correlation was considerably lower when only axial length or peripheral ocular lengths were used.

CONCLUSION

Using the ratios of peripheral ocular length-peripheral corneal radius to predict refractive error is more effective than using peripheral corneal radius or peripheral ocular length alone.

Socio-economic differences in accessing NHS spectacles amongst children with differing refractive errors living in Scotland

BACKGROUND/OBJECTIVES

Adults living in more deprived areas are less likely to attend an eye examination, resulting in greater visual impairment from undiagnosed eye disease and a widening of health inequalities. It is unknown if the introduction of free NHS eye examinations and help with spectacle costs has benefited children in Scotland. This study aimed to explore factors associated with accessing NHS spectacles including level of deprivation, refractive error, urbanity and age.

SUBJECTS/METHODS

NHS-financed General Ophthalmic Services (GOS) 3 supplement the cost of spectacles for children under 16 years. Administrative data on the spectacle refraction dispensed were obtained from Information Services Division (ISD) for mainland Scotland, 2018, and categorised by: Emmetropes/low hyperopes (reference group), myopes and moderate/high hyperopes. Data were linked to the Scottish Index of Multiple Deprivation (SIMD) quintile.

RESULTS

Data included 108, 043 GOS 3 claims. Greater deprivation was associated with greater GOS 3 claims p = 0.041. This was most evident in emmetropic/low hyperopic children and in moderate/high hyperopic children. GOS 3 claims in the myopes group increased with age across all SIMD and decreased with age in the moderate/high hyperope group (all p < 0.001). GOS 3 claims were not associated with urbanity for all Health Boards (p = 0.13).

CONCLUSIONS

Children in areas of greater deprivation and in more rural areas are not disadvantaged in accessing NHS spectacles. This did not vary by refractive error group. This suggests that health policy in Scotland is accessible to those from all deprivation levels and refractive errors.

Exploring eye care pathways, patient priorities and economics in Pakistan: A scoping review and expert consultation study with thematic analysis

Purpose

As the prevalence of eye diseases increases, demand for effective, accessible and equitable eye care grows worldwide. This is especially true in lower and middle‐income countries, which have variable levels of infrastructure and economic resources to meet this increased demand. In the present study we aimed to review the literature on eye care in Pakistan comprehensively, with a particular focus on eye care pathways, patient priorities and economics.

Methods

A systematic scoping review was performed to identify literature relating to eye care in Pakistan. Searches of relevant electronic databases and grey literature were carried out. The results were analysed through a mixed methods approach encompassing descriptive numerical summary and thematic analysis. To consolidate results and define priority areas for future study, expert consultation exercises with key stakeholders were conducted using qualitative semi‐structured interviews.

Results

One hundred and thirty‐two papers (published and unpublished) were included in the final review. The majority (n = 93) of studies utilised a quantitative design. Seven interlinked themes were identified: eye care pathways, burden of eye disease, public views on eye‐related issues, workforce, barriers to uptake of eye care services, quality of eye care services and economic impact of blindness. Research priorities included investigating the eye care workforce, the quality and efficiency of current eye care services, eye care services available in rural Pakistan and the costs and benefits related to eye care provision and sustaining eye care programmes.

Conclusions

To the best of our knowledge, this is the first review to synthesise evidence from papers across the field relating to eye care in Pakistan. As such, this work provides new insights into the achievements of the national eye health programme, challenges in eye care in Pakistan and priority areas for future research.

Towards transforming community eye care: an observational study and time-series analysis of optometrists' prescribing for eye disorders

OBJECTIVES

This study aimed to provide evidence on the therapeutic prescribing activity by community optometrists in Scotland and to determine its impact on workload in general practice and ophthalmology clinics.

STUDY DESIGN

Scottish administrative healthcare data for a 53-month period (November 2013-April 2018) were used to analyse non-medical prescribing practice by optometrists.

METHODS

Using interrupted time-series regression (Autoregressive Integrated Moving Average), we assessed the impact of optometrist prescribing on ophthalmology outpatient attendances and general practice prescribing for eye disorders.

RESULTS

A total of 54,246 items were prescribed by 205 optometrists over the study period. Since the commencement of data recording, optometrist prescribing activity increased steadily from a baseline of zero to 1.2% of all ophthalmic items prescribed. Neither the monthly number of items prescribed nor the size of optometric workforce were associated with a reduction in ophthalmology outpatient appointments over time.

CONCLUSIONS

Optometrists increasingly contribute to community ophthalmic prescribing in Scotland, releasing capacity and lessening general practice, but not secondary care workload. There appears to be an underutilisation of optometrists related to the management of dry eye, which represents an opportunity to release further capacity.

Interventions for visual field defects in people with stroke

BACKGROUND

Visual field defects are estimated to affect 20% to 57% of people who have had a stroke. Visual field defects can affect functional ability in activities of daily living (commonly affecting mobility, reading and driving), quality of life, ability to participate in rehabilitation, and depression and anxiety following stroke. There are many interventions for visual field defects, which are proposed to work by restoring the visual field (restitution); compensating for the visual field defect by changing behaviour or activity (compensation); substituting for the visual field defect by using a device or extraneous modification (substitution); or ensuring appropriate diagnosis, referral and treatment prescription through standardised assessment or screening, or both.

OBJECTIVES

To determine the effects of interventions for people with visual field defects after stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, the Cochrane Eyes and Vision Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, AMED, PsycINFO, and PDQT Databse, and clinical trials databases, including ClinicalTrials.gov and WHO Clinical Trials Registry, to May 2018. We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts.

SELECTION CRITERIA

Randomised trials in adults after stroke, where the intervention was specifically targeted at improving the visual field defect or improving the ability of the participant to cope with the visual field loss. The primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, reading ability, visual field measures, balance, falls, depression and anxiety, discharge destination or residence after stroke, quality of life and social isolation, visual scanning, adverse events, and death.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts, extracted data and appraised trials. We undertook an assessment of methodological quality for allocation concealment, blinding of outcome assessors, method of dealing with missing data, and other potential sources of bias. We assessed the quality of evidence for each outcome using the GRADE approach.

MAIN RESULTS

Twenty studies (732 randomised participants, with data for 547 participants with stroke) met the inclusion criteria for this review. However, only 10 of these studies compared the effect of an intervention with a placebo, control, or no treatment group, and eight had data which could be included in meta-analyses. Only two of these eight studies presented data relating to our primary outcome of functional abilities in activities of daily living. One study reported evidence relating to adverse events.Three studies (88 participants) compared a restitutive intervention with a control, but data were only available for one study (19 participants). There was very low-quality evidence that visual restitution therapy had no effect on visual field outcomes, and a statistically significant effect on quality of life, but limitations with these data mean that there is insufficient evidence to draw any conclusions about the effectiveness of restitutive interventions as compared to control.Four studies (193 participants) compared the effect of scanning (compensatory) training with a control or placebo intervention. There was low-quality evidence that scanning training was more beneficial than control or placebo on quality of life, measured using the Visual Function Questionnaire (VFQ-25) (two studies, 96 participants, mean difference (MD) 9.36, 95% confidence interval (CI) 3.10 to 15.62). However, there was low or very-low quality evidence of no effect on measures of visual field, extended activities of daily living, reading, and scanning ability. There was low-quality evidence of no significant increase in adverse events in people doing scanning training, as compared to no treatment.Three studies (166 participants) compared a substitutive intervention (a type of prism) with a control. There was low or very-low quality evidence that prisms did not have an effect on measures of activities of daily living, extended activities of daily living, reading, falls, or quality of life, and very low-quality evidence that they may have an effect on scanning ability (one study, 39 participants, MD 9.80, 95% CI 1.91 to 17.69). There was low-quality evidence of an increased odds of an adverse event (primarily headache) in people wearing prisms, as compared to no treatment.One study (39 participants) compared the effect of assessment by an orthoptist to standard care (no assessment) and found very low-quality evidence that there was no effect on measures of activities of daily living.Due to the quality and quantity of evidence, we remain uncertain about the benefits of assessment interventions.

AUTHORS' CONCLUSIONS

There is a lack of evidence relating to the effect of interventions on our primary outcome of functional ability in activities of daily living. There is limited low-quality evidence that compensatory scanning training may be more beneficial than placebo or control at improving quality of life, but not other outcomes. There is insufficient evidence to reach any generalised conclusions about the effect of restitutive interventions or substitutive interventions (prisms) as compared to placebo, control, or no treatment. There is low-quality evidence that prisms may cause minor adverse events.

Patient-reported severity of dry eye and quality of life in diabetes

Purpose

The purpose of the study was to assess the relationship between patient-reported severity of dry eye disease (DED), quality of life (QoL), presence of diabetic retinopathy (DR) and length of disease duration in people with type 1 diabetes mellitus (DM1) and type 2 diabetes mellitus (DM2).

Patients and methods

A survey of 152 people (110 with and 42 without diabetes). All participants completed the Ocular Surface Disease Index (OSDI) and Dry Eye-related Quality of Life Score (DEQS) questionnaires.

Results

Forty-four percent of all diabetic subjects reported dry eye symptoms, compared to 29% in the control group. Patients with DM2 reported dry eye symptoms more frequently than those with DM1 (55% and 27% respectively, P=0.001). Dry eye severity was linked to a significant deterioration in QoL in both types of diabetes (DM1, r=0.609 and P=0.036; DM2, r=0.417 and P=0.011). Irrespective of DR, the presence of DED was significantly higher in DM2 compared to DM1 (with DR, P=0.011; without DR, P=0.018).

Conclusion

Dry eye symptoms are associated with reduced QoL and are more common in people with DM2 than in DM1, irrespective of DR status. Routine clinical screening for severe DED could potentially allow for a timely and more effective treatment and could contribute to mitigating the dry eye-associated reduction in QoL in those with DM2.

Assessment of the reliability of endothelial cell-density estimates in the presence of pseudoguttata

PURPOSE

The purpose of this work is to assess the reliability of endothelial cell-density (ECD) estimates in corneas with different severity pseudoguttata.

METHODS

Specular microscopy was undertaken on grade 1, 2, or 3 pseudoguttata patients and age-matched controls aged 52-83 years. On high magnification prints of central cornea, areas of complete cells (all sides visible) and partial 'cells' (one or more sides obscured) were measured manually. Sets of 45 complete cells were selected, as well as 75 cells that were a mixture of complete and partial cells on guttate endothelia. ECD was calculated by a progressive averaging technique.

RESULTS

Each group comprised 12 patients with similar range of ECD values (1,230-4,587 cells/mm(2)). Based on 40 complete cells, ECD could be estimated to within ±3.1% for grade 3 pseudoguttata versus ±2.0% for controls. If a mixture of complete and partial cells were measured, ECD could be estimated to within ±2.8% for grade 3 pseudoguttata images (n = 70 cells) and ±1.1% for controls. The estimated variability increases to substantial levels of ±20% if only ten cells were measured. No statistical differences in ECD were noted between guttate and normal endothelia if only complete cells were measured, but could be different if partial 'cells' were included.

CONCLUSIONS

Providing adequate numbers of complete cells are measured and in the absence of obvious polymegathism, ECD estimates can be made to within around ±3% in the presence of typical but significant pseudoguttata.

Central corneal thickness and intraocular pressure measures in human corneas with endothelial guttata: an observational quality control study

PURPOSE

The aim of the present study was to assess central corneal thickness (CCT) and intraocular pressure (IOP) in eyes where the corneas were affected by different degrees of severity of endothelial pseudo-guttata or guttata.

METHODS

In a prospective, case series observational study, non-contact tonometry and non-contact specular microscopy (NCSM) with pachymetry for central corneal thickness measures were undertaken as routine procedures on predominantly older patients without a history of corneal problems or contact lens wear. For those showing any signs of corneal endothelial abnormalities, images of the central cornea endothelium were further processed to measure the area (as a percentage) occupied by the guttata.

RESULTS

Abnormal endothelial images were obtained from 43 patients (seven with bilateral changes) with an average age of 67.5 years. Between 1.5 and 54.9 per cent of the endothelial images were affected by guttata, which were assigned grade 1 (20 eyes), grade 2 (18 eyes) or grade 3 (11 eyes). When assessed by grade, the central corneal thickness increased and the measured IOP decreased as the guttata became more numerous and confluent. Regression analyses revealed only a weak association between central corneal thickness (p = 0.044, r = 0.149) or the measured IOP (p = 0.090, r = -0.244) and the extent of the guttata (percentage). With the apparently contrasting IOP and central corneal thickness effects, no significant IOP-CCT relationship was noted (p ≥ 0.268, r ≤ 0.160).

CONCLUSIONS

Where corneas have mild-to-modest non-dystrophic endothelial guttata, there may be a less predictable effect of corneal thickness on the outcome of tonometry.

Effect of central corneal thickness on Goldmann applanation tonometry measures - a different result with different pachymeters

PURPOSE

To assess whether the use of Orbscan pachymetry, as an alternative to ultrasound pachymetry, had an effect on the IOP-CCT relationship for Goldmann tonometry in normal human eyes.

PATIENTS AND METHODS

The right eye of 50 healthy subjects, aged 19 to 82 years, were assessed by Orbscan (three scans), and then central corneal thickness (CCT) measured by ultrasound pachymetry (three readings) and Goldmann tonometry performed (three readings).

RESULTS

Goldmann tonometry indicated average IOP values from 9.7 to 20 mm Hg (group mean 14.3 +/- 2.5 mm Hg) that were highly highly correlated with ultrasound pachymetry (r = 0.608, p < 0.001). Orbscan central zone pachymetry (2-mm sample zone) yielded higher values than ultrasound, averaging 0.591 +/- 0.044 mm compared to 0.523 +/- 0.037 mm (p < 0.001), with the differences between the instruments being proportional to the average thickness (p < 0.001; r = 0.461). Notwithstanding, the Goldmann tonometry values were still highly correlated with the Orbscan central zone thickness data (r = 0.595, p < 0.001); but, due to the difference in the thickness data generated by the two pachymeters, the absolute slope of the IOP-CCT relationship was slightly less if Orbscan measures were used, with or without use of the acoustic factor.

CONCLUSION

Orbscan measures of the thickness of a central corneal zone can be used to assess the impact of central corneal thickness on Goldmann tonometry data.

An assessment of regional differences in corneal thickness in normal human eyes, using the Orbscan II or ultrasound pachymetry

BACKGROUND

In recent years, there has been increasing interest in the characteristics of the peripheral cornea close to the limbus, in both tonometry measures and refractive surgery, but there is relatively little information on these characteristics as provided by modern day pachymetry instruments such as the Orbscan (Bausch & Lomb, Rochester, New York). The current study was therefore undertaken to assess the corneal thickness profile along the horizontal meridian by this scanning slit light method, comparing the data with that obtained with an ultrasound pachymeter.

METHODS

Noncontact specular microscopy was first performed on 17 adults (aged between 20 and 64 years) to check that the corneas were normal. Then, 3 assessments of the corneal thickness profile across the horizontal meridian were taken using the Orbscan II, and both the regional map data (7-mm-diameter measurement ring, 1-mm sample zones) and the point data from the numerical pachymetry output were used to extract data at specific locations nominally 0.5 mm apart. Ultrasound pachymetry (under topical anesthesia with benoxinate 0.4%) was then used to obtain thickness values at central, mid-peripheral (2.75 mm), and peripheral locations close to the limbus (4.5 mm).

RESULTS

Specular microscopy yielded mean thickness of 0.529 +/- 0.032 mm, whereas single-point Orbscan readings at the geometric center of the cornea averaged 0.579 +/- 0.037 mm. Orbscan readings around the 7-mm-diameter measurement zone along the horizontal meridian averaged 0.681 +/- 0.034 mm (i.e., were 0.101 mm or 17.6% greater; P < 0.001). Mid-peripheral readings taken from the numerical maps at 2.5 to 3.0 mm averaged 0.645 mm (or 11% higher than central point readings), whereas peripheral readings between 4.0 and 4.5 mm averaged 0.727 mm (i.e., 26% higher than central point values). In marked contrast, ultrasound readings in the mid-periphery (2.75 mm) averaged just 0.553 mm (or 5.5% greater than the central corneal thickness [CCT]) and just 0.612 mm (i.e., 16.6% higher) in the periphery (4.5 mm). CCT profiles generated from the Orbscan numerical output across the horizontal meridian showed a predictable progressive increase in thickness from the center to the 4.5-mm location on both the temporal and nasal side. The mean differences between the Orbscan II and ultrasound pachymetry measures were thus not constant across the cornea. Without correction, these differences were close to 0.05 mm at the center but more than 0.100 mm at the peripheral sites, and proportional differences persisted after application of the default acoustic factor of 0.92 for the Orbscan readings.

CONCLUSIONS

Orbscan II and ultrasound pachymetry measures generate a rather different profile for corneal thickness. The data from the 2 techniques should be considered as reporting different characteristics, rather than attempts being made to align Orbscan measurements to those of the ultrasound method. A single acoustic correction factor cannot be logically applied to all corneal thickness measures made with an Orbscan II.

On the use of Orbscan II to assess the peripheral corneal thickness in humans: a comparison with ultrasound pachometry measures

PURPOSE

To compare the measures of corneal thickness measurements obtained by an optical scanning slit method with those obtained by an ultrasound (US) pachometer, with special interest in the mid-peripheral (2.5 mm from centre) and peripheral (4.5 mm from centre) region of the cornea.

METHODS

Three measures of corneal thickness were taken using Orbscan II and then by US pachometry (under topical anaesthesia with benoxinate 0.4%) on 24 adults, aged 20-58 years and with up to 8.5 D of myopia. The full Orbscan topography maps were used to extract single point data along the horizontal corneal meridian for the geometric centre, 2.5 mm from centre (nasal and temporal) and 4.5 mm (nasal and temporal) from centre. No correction factor was used for the Orbscan data. The same set of measures were made with the US pachometer. In all cases, the averages of three (centre) or six (mid-periphery and periphery) readings were taken as the measurements from each cornea.

RESULTS

Orbscan readings on the right eyes averaged 0.576, 0.632 and 0.712 mm for central, mid-peripheral and peripheral sites with average values for emmetropic subjects (<1 DS, n = 12) being marginally higher than for myopic subjects (average - 4.00 DS, n = 12). For US pachometry, the average values were however 0.522, 0.554 and 0.606 mm. Similar results were obtained on left eyes. Combining data from both eyes also showed that the mean difference between Orbscan II and US measures was not constant across the cornea, being 0.055 +/- 0.014 mm at the centre, 0.080 +/- 0.019 mm at mid-peripheral locations and 0.107 +/- 0.046 mm at the peripheral sites. These differences persisted after application of the generally recommended acoustic factor (x0.92) to all of the Orbscan readings.

CONCLUSIONS

A single acoustic factor correction cannot be applied to all corneal thickness measures made with an Orbscan II to equate the measures to those made with an US pachometer.

Regional Repeatability Measures of Corneal Thickness: Orbscan II and Ultrasound

PURPOSE

To compare repeatability of the measures of corneal thickness obtained by slit-scanning light method (Orbscan II) with those obtained by an ultrasound pachymeter, with special interest in the peripheral region of the cornea.

METHODS

On 24 normal adults, aged 20 to 58 years (average 36 years) with up to -8.5 DS refractive error, three measures of corneal thickness were taken using Orbscan II and then by ultrasound pachymetry (under topical anesthesia with benoxinate 0.4%). The Orbscan central sample zone of 1 mm was selected, or the numerical maps were used to extract single point data along the horizontal corneal meridian to the nasal and temporal sides out to 4.5 mm. Ultrasound readings were taken from the central cornea and at the periphery just inside the limbus (4.5 mm from center) with a 2.4-mm diameter probe.

RESULTS

For a central 1-mm diameter zone, the coefficient of variation (CV) for three consecutive corneal thickness measures was 0.81%+/-0.44%, but was marginally higher (p=0.004), if just the central single point data was taken with Orbscan (0.86%+/-0.45%). Similar repeatability was noted for the numerical output across the temporal side along the horizontal meridian out to 2.5 mm from the center, but farther out to 4 mm and on the nasal side the repeatability was slightly less and around 1.0% (p<0.001). Orbscan point readings of thickness could only sometimes be obtained at 4.5 mm temporally (with a poorer CV of 1.32%) and very rarely at 4.5 mm on the nasal side. No absolute differences in Orbscan repeatability were noted when comparing emmetropic with myopic subjects (p>or=0.5). Ultrasound pachymetry readings across the central zone were repeatable to 0.82%+/-0.67%. When measured with the edge of the ultrasound probe just touching the limbus, the repeatability of ultrasound readings was 1.37%+/-1.10% temporally and 1.49%+/-1.02% nasally, but neither was statistically worse that the most peripheral readings for Orbscan (p>or=0.210). However, it was also noted that the absolute values of corneal thickness, even with the application of the 0.92 acoustic factor, were 0.010 mm greater for Orbscan at the center and 0.040 mm in the corneal periphery.

CONCLUSIONS

Orbscan II provides the clinician with a repeatable noninvasive method of measuring corneal thickness that is not necessarily any better than ultrasound pachymetry, and should not be considered as interchangeable with that for ultrasound.