Glaucoma detection in the community: does ongoing training of optometrists have a lasting effect?

The effectiveness of interventions for optometric referrals into the hospital eye service: A review

PURPOSE

Ophthalmic services are currently under considerable stress; in the UK, ophthalmology departments have the highest number of outpatient appointments of any department within the National Health Service. Recognising the need for intervention, several approaches have been trialled to tackle the high numbers of false-positive referrals initiated in primary care and seen face to face within the hospital eye service (HES). In this mixed-methods narrative synthesis, we explored interventions based on their clinical impact, cost and acceptability to determine whether they are clinically effective, safe and sustainable. A systematic literature search of PubMed, MEDLINE and CINAHL, guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), was used to identify appropriate studies published between December 2001 and December 2022.

RECENT FINDINGS

A total of 55 studies were reviewed. Four main interventions were assessed, where two studies covered more than one type: training and guidelines (n = 8), referral filtering schemes (n = 32), asynchronous teleophthalmology (n = 13) and synchronous teleophthalmology (n = 5). All four approaches demonstrated effectiveness for reducing false-positive referrals to the HES. There was sufficient evidence for stakeholder acceptance and cost-effectiveness of referral filtering schemes; however, cost comparisons involved assumptions. Referral filtering and asynchronous teleophthalmology reported moderate levels of false-negative cases (2%-20%), defined as discharged patients requiring HES monitoring.

SUMMARY

The effectiveness of interventions varied depending on which outcome and stakeholder was considered. More studies are required to explore stakeholder opinions around all interventions. In order to maximise clinical safety, it may be appropriate to combine more than one approach, such as referral filtering schemes with virtual review of discharged patients to assess the rate of false-negative cases. The implementation of a successful intervention is more complex than a 'one-size-fits-all' approach and there is potential space for newer types of interventions, such as artificial intelligence clinical support systems within the referral pathway.

The performance and confidence of clinicians in training in the analysis of ophthalmic images within a work-integrated teaching model

PURPOSE

A fundamental clinical skill is the recognition of artefacts within the outputs of advanced imaging modalities. However, current teaching programmes of healthcare practitioners are becoming increasingly challenged to provide practical exposure within an already crowded curriculum. This study evaluates the impact of a novel work-integrated teaching model on the confidence and competence of clinicians in the use of optical coherence tomography (OCT) and the recognition of its artefacts. The outcomes were then used to develop a model to predict performance and guide teaching strategies.

METHODS

We prospectively evaluated a 6-week clinical placement for final year optometry students within a diagnostic eye clinic in 2018-2020. Participants completed a quiz on the identification of common OCT artefacts and rated their confidence levels on key areas of OCT application using a five-point Likert scale. Both were completed before (pre-rotation) and after (post-rotation) the placement. The cohort was divided into two groups; the first group was used to assess the impact of the placement and derive the prediction model for post-placement performance, which was then validated against the second group.

RESULTS

A significant improvement in detecting OCT imaging artefacts was seen upon completion of the placement, which was greater in participants with lower entry level performance. Across all OCT artefact subtypes, there was an improvement in detecting segmentation error, delineation error and media opacities. A model predicting post-placement student performance was developed using entry level knowledge base as the key dependent variable. Self-rated confidence improved across all domains of OCT application but was not found to be a direct predictor of actual performance.

CONCLUSIONS

These results highlight the benefit of a work-integrated learning programme on both academic performance and confidence whilst identifying entry level knowledge base as the key variable predicting improvement. Tailored teaching incorporating entering knowledge is the best predictor of improvement during clinical placements. Integrating clinicians into a work-integrated setting with tailored teaching and comprehensive practical exposure can be an effective method for training future or current healthcare professionals.

Impact of referral refinement on management of glaucoma suspects in Australia

BACKGROUND

In ageing populations, the prevalence of chronic diseases such as glaucoma is projected to increase, placing additional demands on limited health-care resources. In the UK, the demand for secondary care in hospital eye clinics was inflated by high rates of false positive glaucoma referrals. Collaborative care models incorporating referral refinement, whereby glaucoma suspect referrals are triaged by suitably trained optometrists through further testing, can potentially reduce false positive referrals. This study examined the impact of a referral refinement model on the accuracy of glaucoma referrals in Australia.

METHODS

Optometrist-initiated glaucoma suspect referrals to the Glaucoma Management Clinic (Sydney, Australia) were prospectively recruited. Glaucoma suspect referrals arising from two pathways were eligible for inclusion, either directly from a community optometrist (standard care) or following comprehensive assessment at the Centre for Eye Health (referral refinement). Main outcome measures were the positive predictive value and false positive rate of referrals. The impact of referral letter content on management outcomes was also investigated.

RESULTS

Of 464 referrals received between March 2015 and June 2018, 252 were for treatment of naïve glaucoma suspects and eligible for inclusion. Following ophthalmological assessment, 45.6 per cent (n = 115/252) were prescribed treatment for open angle glaucoma or ocular hypertension. Positive predictive value of community optometry referrals was 33.8 per cent (n = 25/74) and 50.6 per cent (n = 90/178) following referral refinement. The first visit discharge (false positive) rate was 26 per cent (n = 19/74) for community referrals compared to four per cent (n = 8/178) with referral refinement. Positive predictive value increased with the number of abnormal clinical examination findings associated with referral (χ² test, p < 0.0001). The number of abnormal findings reported in referrals was significantly higher with referral refinement compared to without (n = 1.9 versus 1.5, t-test, p < 0.0001).

CONCLUSION

Referral refinement can improve the diagnostic accuracy of optometry-initiated referrals for glaucoma suspects in Australia, thereby decreasing unnecessary referrals to hospital and other secondary clinics.

Impact of optical coherence tomography on diagnostic decision-making by UK community optometrists: a clinical vignette study

Purpose

In recent years, there has been widespread investment in imaging technologies by community optometrists in the UK, most notably optical coherence tomography (OCT). The aim of the current study was to determine the value of OCT in the diagnosis of posterior segment diseases in a representative sample of community optometrists using a clinical vignette methodology.

Methods

A group of community optometrists (n = 50) initially completed a standardised training package on OCT interpretation followed by a computer‐based assessment featuring 52 clinical vignettes, containing images of healthy (n = 8) or glaucomatous (n = 18) discs or healthy (n = 8) or diseased (n = 18) fundi. Each vignette featured either a single fundus/disc photographic image, or a combination of a fundus/disc image with the corresponding OCT scan. An expert panel confirmed that the fundus images presented alone and those in combination with OCT data were of a similar level of difficulty and that the cases were typical of those seen in primary care. For each case, the optometrist selected their diagnosis from a pull‐down list and reported their confidence in their decision using a 10‐point Likert scale. Pairwise comparisons of the fundus image alone and fundus image/OCT combination were made for both diagnostic performance and confidence.

Results

The mean percentage of correct diagnoses using fundus imaging alone was 62% (95% CI 59–64%) and for the combination of fundus image/OCT was 80% (95% CI 77–82%). The mean false negative rate with fundus alone was 27% reducing to 13% with the OCT combination. Median confidence scores for fundus imaging alone was 8.0 (IQR 7.0–8.0) and 8.3 (IQR 8.0–9.0) for the combination. Improvements in performance and confidence were statistically significant (p < 0.001).

Conclusion

The results from this vignette study suggests that OCT improves optometrists’ diagnostic performance compared to fundus observation alone. These initial results suggest that OCT provides valuable additional data that could augment case‐finding for glaucoma and retinal disease; however, further research is needed to assess its diagnostic performance in a routine clinical practice setting.

Systematic review of the appropriateness of eye care delivery in eye care practice

BACKGROUND

Health care systems are continually being reformed, however care improvement and intervention effectiveness are often assumed, not measured. This paper aimed to review findings from published studies about the appropriateness of eye care delivery, using existing published evidence and/or experts' practice and to describe the methods used to measure appropriateness of eye care.

METHODS

A systematic search was conducted using Medline, Embase and CINAHL (2006 to September 2016). Studies reporting the processes of eye care delivery against existing published evidence and/or experts' practice were selected. Data was extracted from published reports and the methodological quality using a modified critical appraisal tool. The primary outcomes were percentage of appropriateness of eye care delivery. This study was registered with PROSPERO, reference CRD42016049974.

RESULTS

Fifty-seven studies were included. Most studies assessed glaucoma and diabetic retinopathy and the overall methodological quality for most studies was moderate. The ranges of appropriateness of care delivery were 2-100% for glaucoma, 0-100% for diabetic retinopathy and 0-100% for other miscellaneous conditions. Published studies assessed a single ocular condition, a sample from a single centre or a single domain of care, but no study has attempted to measure the overall appropriateness of eye care delivery.

CONCLUSIONS

These findings indicated a wide range of appropriateness of eye care delivery, for glaucoma and diabetic eye care. Future research would benefit from a comprehensive approach where appropriateness of eye care is measured across multiple conditions with a single methodology, to guide priorities within eye care delivery and monitor quality improvement initiatives.

Prospective study of glaucoma referrals across Europe: are we using resources wisely?

BACKGROUND

To investigate the outcomes of glaucoma referrals across different European countries.

METHODS

250 patients newly referred to tertiary referral glaucoma specialist practices in the UK, Hungary, Slovenia, Italy and Greece were prospectively enrolled (50 consecutive patients per centre). Referral accuracy and predictive value of referral criteria for an intervention or further monitoring (positive predictive value) were analysed.

RESULTS

Same-day discharges occurred in 43% (95% CI 39% to 75%) (12/28) of optometrist-initiated referrals (UK only), 37% (95% CI 30% to 45%) (59/158) of ophthalmologist-initiated referrals (all centres) and 54% (95% CI 40% to 68%) (26/48) of self-referrals (Hungary, Italy and Greece). The percentages from all referral sources were 46% (95% CI 32% to 60%) in the UK, 56% (95% CI 44% to 70%) in Hungary, 30% (95% CI 17% to 43%) in Slovenia, 22% (95% CI 11% to 34%) in Italy and 60% (95% CI 46% to 74%) in Greece (p<0.001). Overall, the referring criterion was confirmed in 54% (95% CI 45% to 63%) (64/119) for intraocular pressure (IOP) >21 mm Hg, 56% (95% CI 43% to 69%) (33/59) for a suspicious optic disc and 61% (95% CI 45% to 77%) (22/36) for a suspicious visual field, with large between-country differences (p<0.05 for all comparisons). Of all referrals, 32% (95% CI 26% to 37%) were initiated on the basis of IOP >21 mm Hg only. By combining the IOP criterion with any other referring criterion, the positive predictive value increased from 56% (95% CI 45% to 67%) to at least 89% (95% CI 68% to 100%). In the UK, a hypothetical IOP threshold of >26 mm Hg, as a requirement for IOP-only referrals, would reduce IOP-only referrals by 44%, while not missing any definite glaucoma cases.

CONCLUSION

The accuracy of referrals was poor in the UK and the other countries. Requiring a combination of criteria and raising the IOP threshold for IOP-only referrals are needed to cut waste in clinical care.

Automated imaging technologies for the diagnosis of glaucoma: a comparative diagnostic study for the evaluation of the diagnostic accuracy, performance as triage tests and cost-effectiveness (GATE study)

BACKGROUND

Many glaucoma referrals from the community to hospital eye services are unnecessary. Imaging technologies can potentially be useful to triage this population.

OBJECTIVES

To assess the diagnostic performance and cost-effectiveness of imaging technologies as triage tests for identifying people with glaucoma.

DESIGN

Within-patient comparative diagnostic accuracy study. Markov economic model comparing the cost-effectiveness of a triage test with usual care.

SETTING

Secondary care.

PARTICIPANTS

Adults referred from the community to hospital eye services for possible glaucoma.

INTERVENTIONS

Heidelberg Retinal Tomography (HRT), including two diagnostic algorithms, glaucoma probability score (HRT-GPS) and Moorfields regression analysis (HRT-MRA); scanning laser polarimetry [glaucoma diagnostics (GDx)]; and optical coherence tomography (OCT). The reference standard was clinical examination by a consultant ophthalmologist with glaucoma expertise including visual field testing and intraocular pressure (IOP) measurement.

MAIN OUTCOME MEASURES

(1) Diagnostic performance of imaging, using data from the eye with most severe disease. (2) Composite triage test performance (imaging test, IOP measurement and visual acuity measurement), using data from both eyes, in correctly identifying clinical management decisions, that is 'discharge' or 'do not discharge'. Outcome measures were sensitivity, specificity and incremental cost per quality-adjusted life-year (QALY).

RESULTS

Data from 943 of 955 participants were included in the analysis. The average age was 60.5 years (standard deviation 13.8 years) and 51.1% were females. Glaucoma was diagnosed by the clinician in at least one eye in 16.8% of participants; 37.9% of participants were discharged after the first visit. Regarding diagnosing glaucoma, HRT-MRA had the highest sensitivity [87.0%, 95% confidence interval (CI) 80.2% to 92.1%] but the lowest specificity (63.9%, 95% CI 60.2% to 67.4%) and GDx had the lowest sensitivity (35.1%, 95% CI 27.0% to 43.8%) but the highest specificity (97.2%, 95% CI 95.6% to 98.3%). HRT-GPS had sensitivity of 81.5% (95% CI 73.9% to 87.6%) and specificity of 67.7% (95% CI 64.2% to 71.2%) and OCT had sensitivity of 76.9% (95% CI 69.2% to 83.4%) and specificity of 78.5% (95% CI 75.4% to 81.4%). Regarding triage accuracy, triage using HRT-GPS had the highest sensitivity (86.0%, 95% CI 82.8% to 88.7%) but the lowest specificity (39.1%, 95% CI 34.0% to 44.5%), GDx had the lowest sensitivity (64.7%, 95% CI 60.7% to 68.7%) but the highest specificity (53.6%, 95% CI 48.2% to 58.9%). Introducing a composite triage station into the referral pathway to identify appropriate referrals was cost-effective. All triage strategies resulted in a cost reduction compared with standard care (consultant-led diagnosis) but with an associated reduction in effectiveness. GDx was the least costly and least effective strategy. OCT and HRT-GPS were not cost-effective. Compared with GDx, the cost per QALY gained for HRT-MRA is £22,904. The cost per QALY gained with current practice is £156,985 compared with HRT-MRA. Large savings could be made by implementing HRT-MRA but some benefit to patients will be forgone. The results were sensitive to the triage costs.

CONCLUSIONS

Automated imaging can be effective to aid glaucoma diagnosis among individuals referred from the community to hospital eye services. A model of care using a triage composite test appears to be cost-effective.

FUTURE WORK

There are uncertainties about glaucoma progression under routine care and the cost of providing health care. The acceptability of implementing a triage test needs to be explored.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Repeatability and comparison of clinical techniques for anterior chamber angle assessment

PURPOSE

To assess the repeatability of gonioscopy, van Herick method and anterior segment Optical Coherence Tomography (AS-OCT) and determine the agreement between these techniques within a community optometry setting.

METHODS

Gonioscopy, van Herick method and AS-OCT imaging were performed by an optometrist on two occasions, 1 month apart, on 80 subjects aged over 40 years recruited from community optometry practices. Anterior segment images were captured with a spectral domain OCT (Topcon 3D OCT-2000; wavelength 840 nm) set to the Anterior Segment (AS) mode. Eyes were graded as open or occludable for each method. AS-OCT images from both visits were graded by a second optometrist masked to the gonioscopy and van Herick method results, and the visit on which the images were acquired. Cohen's kappa (κ) was used to describe the intra-observer repeatability. Likelihood ratios, sensitivity and specificity of van Herick method and AS-OCT were calculated, using gonioscopy as the reference standard.

RESULTS

Measurements were obtained from 80 eyes of 80 subjects. In four cases, AS-OCT images were un-gradable due to difficulty in locating the scleral spur. The repeatability of gonioscopy was fair κ = 0.29, while that of the van Herick method (κ = 0.54) and AS-OCT (κ = 0.47) were somewhat better. The van Herick method showed good sensitivity (visit 1: 75%, visit 2: 69%) and high specificity (visit 1: 88%, visit 2: 96%). The sensitivity of AS-OCT was fair (visit 1: 46%, visit 2: 25%), but specificity was high (visit 1: 87%. visit 2: 89%).

CONCLUSION

Intra-observer repeatability was better for van Herick method and for AS-OCT than for gonioscopy, despite the latter being considered the gold standard method. The van Herick method appeared to be more sensitive than AS-OCT when identifying eyes at risk of angle closure. A standalone anterior segment OCT with a longer wavelength laser could afford better visualisation of the angle, and might therefore be expected to enable the examiner to make more precise classifications. These instruments are not widely used by optometrists in clinical practice in the UK at present.

Assessment of optic disc photographs for glaucoma by UK optometrists: the Moorfields Optic Disc Assessment Study (MODAS)

PURPOSE

To assess the ability of UK optometrists to accurately discriminate between stereoscopic photographs of healthy and glaucomatous optic discs.

METHODS

An online survey, including questions relating to qualification, practice environment, and diagnostic methods was completed by 1256 optometrists. Based on their responses, 208 (17%) were selected to undertake an online disc assessment exercise. Optometrists evaluated the same disc images previously assessed by European ophthalmologists as part of the European Optic Disc Assessment Trial (EODAT); the task was to state if the disc appeared healthy or glaucomatous. There were 110 stereoscopic disc images, of which 40 were healthy, 48 glaucomatous, and six ocular hypertensive, with 16 duplicates images. Sensitivity, specificity and overall accuracy were calculated and compared between optometrist groups and with the EODAT ophthalmologists using permutation analysis.

RESULTS

Median sensitivity was 0.92 (95% CI: 0.70, 1.00) and median specificity was 0.74 (95% CI: 0.62, 0.88). Median overall accuracy was 80% (95% CI: 67%, 88%). Agreement between optometrists was moderate (Fleiss' κ: 0.57). Optometrists with higher qualifications did not have overall higher sensitivity than those without (p = 0.23), but had higher specificity (p = 0.001) and higher overall accuracy (p < 0.001). Optometrists displayed higher sensitivity but lower specificity than the EODAT ophthalmologists.

CONCLUSION

UK optometrists displayed a high sensitivity and moderate specificity when assessing optic discs for the presence of glaucoma, in the context of this study.

NICE - impact on glaucoma case detection

AIM

To investigate the impact of publication of the National Institute of Clinical Excellence (NICE) guidelines ('Glaucoma: diagnosis and management of chronic open angle glaucoma and ocular hypertension') in April 2009, on the referrals for suspect glaucoma to Moorfields Community Eye Clinic (MCEC) at Ealing Hospital.

METHODS

The clinical data from all optometrist initiated referrals for suspect glaucoma and ocular hypertension were scrutinised by a Consultant Ophthalmologist for a 2 month period, 6 months after the publication of the NICE guidance. Each was then categorised into the following groups: glaucoma positive; glaucoma suspect; glaucoma negative; ocular hypertension (OHT) requiring further follow up in clinic; ocular hypertension to be followed up by community optometrist; other. The positive predictive value (PPV) was then calculated and a historical comparison made with previous studies.

RESULTS

A total of 110 new referrals were assessed during the collection period, which reflects a marked increase in numbers attending. However, there was no increase in absolute numbers of glaucoma and glaucoma suspects identified. The absolute numbers of ocular hypertensive patients rose. The PPV fell to 0.25, which is lower than found in previous studies.

CONCLUSIONS

The rising number of new referrals and the unchanged absolute numbers of glaucoma and glaucoma suspects identified following publication of the NICE guidance, in addition to a lower PPV, makes us question what advantage in improved case detection this represents. Furthermore, is this a cost effective strategy? We believe the next step is to introduce a repeat review, with carefully considered clinical governance of any new scheme.

Optometrists referrals for glaucoma assessment: a prospective survey of clinical data and outcomes

AIM

The aim of this study is to determine the outcomes following referral for glaucoma from routine optometric practice and the positive predictive value (PPV).

METHODS

A prospective study of 441 referrals for glaucoma in the Portsmouth area was performed over 6 months. A positive outcome was defined when the patient had the diagnosis of glaucoma made or if there was a high index of suspicion of glaucoma requiring follow-up. The PPV was determined from positive outcome number/referral number.

RESULTS

The overall PPV was 0.37 (95% confidence interval 0.33-0.42). Open-angle glaucoma (OAG) was confirmed in 33 (7%) patients. A diagnosis of ocular hypertension was made in 49 (11%) patients and glaucoma suspect in 92 (21%) referrals. Two-thirds of optometrists recorded all 3 assessments: fields, intraocular pressure (IOP) and disc appearance, a figure representing 293 referrals (PPV 0.37). However the greatest referral accuracy was seen when only discs and IOPs were recorded (PPV 0.47). When all three tests were given as reasons for suspicion for glaucoma, the PPV was 0.71. The number of patients diagnosed with OAG from Portsea Island during the study period was 7, whereas the expected number of diagnosed patients was 29.

CONCLUSION

Wider use of perimetry by optometrists and increased reporting of all three tests has not led to an increase in PPV. There remain a considerable number of undiagnosed patients with glaucoma in the population.

The quality of optometrists' referral letters for glaucoma

PURPOSE

The purpose of the study was to evaluate the quality of content of optometrist-initiated glaucoma referral letters arriving at the appointment booking centre at Moorfields Eye Hospital (MEH).

METHODS

The minimum standard of information required for an ophthalmologist to determine the appropriateness and urgency of glaucoma suspect referral was determined, and criteria for three standards of referral letter formulated: 'Ideal', 'Acceptable' and 'Fail'. These standards were applied to a prospective review of all optometrist-derived referrals for glaucoma or suspected glaucoma cases arriving in the MEH booking centre over a 4-month period. The contents of each letter were scrutinised and classified based on the criteria within each standard.

RESULTS

Forty-nine per cent of referral letters were found to be of 'acceptable' quality, 7%'ideal' quality and the remainder classed as "fail". The main reason for failure was an omission of non-clinical information, including patient and/or referring practice details, although 26% of letters failed to include an optic disc evaluation and 6% failed to provide intra-ocular pressure measurements. Two-thirds of 'acceptable' letters did not reach the 'ideal' standard due to a lack of discussion of risk factors, visual field analysis or recommendations for referral speed.

DISCUSSION

The information gleaned from this prospective study indicates a need to improve the quality of optometrists' glaucoma referral letters, particularly with respect to completion of all the items set out on the General Ophthalmic Services (GOS) 18 referral form.

The accuracy of accredited glaucoma optometrists in the diagnosis and treatment recommendation for glaucoma

AIM

To compare the diagnostic performance of accredited glaucoma optometrists (AGO) for both the diagnosis of glaucoma and the decision to treat with that of routine hospital eye care, against a reference standard of expert opinion (a consultant ophthalmologist with a special interest in glaucoma).

METHODS

A directly comparative, masked, performance study was undertaken in Grampian, Scotland. Of 165 people invited to participate, 100 (61%) were examined. People suspected of having glaucoma underwent, within one month, a full ophthalmic assessment in both a newly established community optometry led glaucoma management scheme and a consultant led hospital eye service.

RESULTS

Agreement between the AGO and the consultant ophthalmologist in diagnosing glaucoma was substantial (89%; kappa = 0.703, SE = 0.083). Agreement over the need for treatment was also substantial (88%; kappa = 0.716, SE = 0.076). The agreement between the trainee ophthalmologists and the consultant ophthalmologist in the diagnosis of glaucoma and treatment recommendation was moderate (83%, kappa = 0.541, SE = 0.098, SE = 0.98; and 81%, kappa = 0.553, SE = 0.90, respectively). The diagnostic accuracy of the optometrists in detecting glaucoma in this population was high for specificity (0.93 (95% confidence interval, 0.85 to 0.97)) but lower for sensitivity (0.76 (0.57 to 0.89)). Performance was similar when accuracy was assessed for treatment recommendation (sensitivity 0.73 (0.57 to 0.85); specificity 0.96 (0.88 to 0.99)). The differences in sensitivity and specificity between AGO and junior ophthalmologist were not statistically significant.

CONCLUSIONS

Community optometrists trained in glaucoma provided satisfactory decisions regarding diagnosis and initiation of treatment for glaucoma. With such additional training in glaucoma, optometrists are at least as accurate as junior ophthalmologists but some cases of glaucoma are missed.