Selective laser trabeculoplasty (SLT) performed by optometrists for patients with glaucoma and ocular hypertension: a scoping review

Selective laser trabeculoplasty (SLT) has been established as an effective treatment to lower intraocular pressure in people with glaucoma and ocular hypertension. The procedure is typically within the remit of ophthalmologists; however, there is potential to upskill optometrists and other healthcare professionals (HCPs) to deliver the treatment. We conducted a scoping review to identify the current global landscape of HCP-delivered SLT and describe training features, clinical effectiveness and safety. Relevant articles were identified through online database searches and grey literature sources. Four articles were selected for full inclusion. This review identified training programmes for optometrist-delivered SLT in the UK and the USA. The findings indicate that more research is needed to clarify training requirements and clinical effectiveness

Processing of color signals in female carriers of color vision deficiency

The aim of this study was to assess the chromatic sensitivity of carriers of color deficiency, specifically in relation to dependence on retinal illuminance, and to reference these findings to the corresponding red-green (RG) thresholds measured in normal trichromatic males. Thirty-six carriers of congenital RG color deficiency and 26 normal trichromatic males participated in the study. The retinal illuminance was estimated by measuring the pupil diameter and the optical density of the lens and the macular pigment. Each subject's color vision was examined using the Color Assessment and Diagnosis (CAD) test, the Ishihara and American Optical pseudoisochromatic plates, and the Nagel anomaloscope. Carriers of deuteranopia (D) and deuteranomaly (DA) had higher RG thresholds than male trichromats (p < 0.05). When referenced to male trichromats, carriers of protanomaly (PA) needed 28% less color signal strength; carriers of D required ∼60% higher thresholds at mesopic light levels. Variation in the L:M ratio and hence the absolute M-cone density may be the principal factor underlying the poorer chromatic sensitivity of D carriers in the low photopic range. The increased sensitivity of PA carriers at lower light levels is consistent with the pooling of signals from the hybrid M' and the M cones and the subsequent stronger inhibition of the rods. The findings suggest that signals from hybrid photopigments may pool preferentially with the spectrally closest "normal" pigments

Selective laser trabeculoplasty (SLT) performed by optometrists—enablers and barriers to a shift in service delivery

Background/objectives: To explore the acceptability, training requirements, enablers and barriers of optometrist-delivered SLT. / Subjects/methods: Optometrists, fellowship and consultant grade ophthalmologists, hospital managers and patients were interviewed using pre-defined topic guides. Interviews were audio-recorded, transcribed, and subjected to thematic analysis. Overarching themes were defined by the study aims and the topic guides; subthemes were derived from the interview data. / Results: Sixty-six participants (three managers, eight glaucoma specialist consultant ophthalmologists, seven clinical glaucoma fellows, 12 optometrists (two of them performing SLT), two ophthalmic nurses and 34 patients) participated in the study. Overarching themes (and subthemes) were: necessity of non-medical SLT delivery, clinical practice and training, advantages, disadvantages, concerns, challenges, community delivery of SLT, patient values and other healthcare professionals that could also deliver SLT. / Conclusions: Certain clinical pre-requisites, such as gonioscopy and independent prescribing rights, were perceived as necessary for undertaking SLT training. An optometrist-delivered SLT service was expected to benefit the NHS, but there was an identified need of a standardised training scheme and robust governance. Patients were accepting of an optometrist-delivered SLT service in the hospital eye service

Clinical risk stratification in glaucoma

Glaucoma is the leading cause of preventable sight loss in the United Kingdom and the provision of timely glaucoma care has been highlighted as a significant challenge in recent years. Following a recent high-profile investigation, The Healthcare Safety Investigation Branch recommended the validation of risk stratification models to safeguard the vision-related quality of life of glaucoma patients. There continues to be no nationally agreed evidence-based risk stratification model for glaucoma care across the United Kingdom. Some models have used simple measures of disease staging such as visual field mean deviation as surrogates for risk, but more refined, individualised risk stratification models should include factors related to both visual impairment and visual disability. Candidate tools should also incorporate both ocular and systemic co-morbidities, rate of disease progression, visual needs and driving status and undergo clinical refinement and validation to justify implementation. The disruption to routine glaucoma care caused by the COVID-19 pandemic has only highlighted the importance of such risk stratification models and has accelerated their development, application and evaluation. This review aims to critically appraise the available evidence underpinning current approaches for glaucoma risk stratification and to discuss how these may be applied to contemporary glaucoma care within the United Kingdom. Further research will be essential to justify and validate the utility of glaucoma risk stratification models in everyday clinical practice

A qualitative study of stakeholder views regarding participation in locally commissioned enhanced optometric services

Objectives: To explore the views of optometrists, general practitioners (GPs) and ophthalmologists regarding the development and organisation of community-based enhanced optometric services. Design: Qualitative study using free-text questionnaires and telephone interviews. Setting: A minor eye conditions scheme (MECS) and a glaucoma referral refinement scheme (GRRS) are based on accredited community optometry practices. Participants: 41 optometrists, 6 ophthalmologists and 25 GPs. Results: The most common reason given by optometrists for participation in enhanced schemes was to further their professional development; however, as providers of ‘for-profit’ healthcare, it was clear that participants had also considered the impact of the schemes on their business. Lack of fit with the ‘retail’ business model of optometry was a frequently given reason for non-participation. The methods used for training and accreditation were generally thought to be appropriate, and participating optometrists welcomed the opportunities for ongoing training. The ophthalmologists involved in the MECS and GRRS expressed very positive views regarding the schemes and widely acknowledged that the new care pathways would reduce unnecessary referrals and shorten patient waiting times. GPs involved in the MECS were also very supportive. They felt that the scheme provided an ‘expert’ local opinion that could potentially reduce the number of secondary care referrals. Conclusions: The results of this study demonstrated strong stakeholder support for the development of community-based enhanced optometric services. Although optometrists welcomed the opportunity to develop their professional skills and knowledge, enhanced schemes must also provide a sufficient financial incentive so as not to compromise the profitability of their business

Macular pigment spatial profiles in South Asian and white subjects

Purpose: Variability in central macular pigment optical density (MPOD) has been reported amongst healthy individuals. These variations seem to be related to risk factors of age-related macular degeneration, such as female gender, smoking, and ethnicity. This study investigates the variations in MPOD spatial profiles amongst ethnicities. Methods: Using heterochromatic flicker photometry (HFP), MPOD was measured at 7 retinal locations in 54 healthy young South Asian and 19 White subjects of similar age. Macular pigment spatial profiles were classified as either typical ‘exponential’, atypical ‘ring-like’ or atypical ‘central dip’. Results: Central MPOD was significantly greater in South Asian (0.56 ± 0.17) compared to White subjects (0.45 ± 0.18; P = 0.015). Integrated MPOD up to 1.8° i.e. MPODav(0-1.8) was also significantly increased in Asian (0.34 ± 0.09) versus White subjects (0.27 ± 0.10; P = 0.003). MPODav(0-1.8) was significantly increased in all subjects presenting a ring-like profile (0.35 ± 0.08) or central dip profile (0.39 ± 0.09), compared to typical exponential profiles (0.28 ± 0.09; P < 0.0005). We found a statistically significant association between ethnicity and spatial profile type (P = 0.008), whereby an exponential profile was present in 79% of White compared to 41% of the South Asian subjects. Conclusion: Central MPOD, MPODav(0-1.8), and the prevalence of atypical spatial profiles were significantly increased in South Asian compared to White subjects. Atypical profiles resulted in increased integrated MPOD up to 1.8° and may therefore offer enhanced macular protection from harmful blue light

Capturing age-related changes in functional contrast sensitivity with decreasing light levels in monocular and binocular vision

Purpose: It is challenging to separate the effects of normal aging of the retina and visual pathways independently from optical factors, decreased retinal illuminance and early stage disease. This study determined limits to describe the effect of light level on normal, age-related changes in monocular and binocular functional contrast sensitivity. Methods: 95 participants aged 20 to 85 were recruited. Contrast thresholds for correct orientation discrimination of the gap in a Landolt C optotype were measured using a 4 four-alternative, forced-choice (4AFC) procedure at screen luminances from 34 to 0.12 cd/m2, at the fovea and parafovea (0° and ±4°). Pupil size was measured continuously. The Health of the Retina index (HRindex) was computed to capture the loss of contrast sensitivity with decreasing light level. Participants were excluded if they exhibited performance outside the normal limits of interocular differences or HRindex values, or signs of ocular disease. Results: Parafoveal contrast thresholds showed a steeper decline and higher correlation with age at the parafovea than the fovea. 83% of participants with clinical signs of ocular disease had HRindex values outside the normal limits. Binocular summation of contrast signals declined with age, independent of interocular differences. Conclusion: The HRindex worsens more rapidly with age at the parafovea, consistent with histological findings of rod loss and its link to age-related degenerative disease of the retina. The HRindex, and interocular differences could be used to screen for and separate the earliest stages of sub-clinical disease from changes caused by normal aging

Clinical safety of a minor eye conditions scheme in England delivered by community optometrists

Objective The aim of this study was to monitor the activity and evaluate the clinical safety of a minor eye conditions scheme (MECS) conducted by accredited community optometrists in Lambeth and Lewisham, London. Methods and analysis Optometrists underwent an accredited training programme, including attendance at hospital eye services (HES) clinics. Patients who satisfied certain inclusion criteria were referred to accredited MECS optometrists by their general practitioners (GPs) or could self-refer. Data were extracted from clinical records. A sample of MECS clinical records was graded to assess the quality of the MECS optometrists’ clinical management decisions. Referrals to the HES were assessed by the collaborating ophthalmologists and feedback was provided. Results A total of 2123 patients (mean age 47 years) were seen over 12 months. Two-thirds of the patients (67.3%) were referred by their GP. The most common reasons for patients needing a MECS assessment were ‘red eye’ (36.7% of patients), ‘painful white eye’ (11.1%), ‘flashes and floaters’ (10.2%); 8.7% of patients had a follow-up appointment. Of the patients seen, 75.1% were retained in the community, 5.7% were referred to their GP and 18.9% were referred to the HES. Of the HES referrals, 49.1% were routine, 22.6% urgent and 28.3% emergency. Of the records reviewed, 94.5% were rated as appropriately managed; 89.2% of the HES referrals were considered appropriate. Conclusion The findings of this study indicate that optometrists are in a good position to work very safely within the remits of the scheme and to assess risk

Evaluation of a minor eye conditions scheme delivered by community optometrists

BACKGROUND: The establishment of minor eye conditions schemes (MECS) within community optometric practices provides a mechanism for the timely assessment of patients presenting with a range of acute eye conditions. This has the potential to reduce waiting times and avoid unnecessary referrals to hospital eye services (HES). OBJECTIVE: To evaluate the clinical effectiveness, impact on hospital attendances and patient satisfaction with a minor eye service provided by community optometrists. METHODS: Activity and outcome data were collected for 12 months in the Lambeth and Lewisham MECS. A patient satisfaction questionnaire was given to patients at the end of their MECS appointment. A retrospective difference-in-differences analysis of hospital activity compared changes in the volume of referrals by general practitioners (GPs) from a period before (April 2011-March 2013) to after (April 2013-March 2015) the introduction of the scheme in Lambeth and Lewisham relative to a neighbouring area (Southwark) where the scheme had not been commissioned. Appropriateness of case management was assessed by consensus using clinical members of the research team. RESULTS: A total of 2123 patients accessed the scheme. Approximately two-thirds of patients (67.5%) were referred by their GP. The commonest reasons for patients attending for a MECS assessment were 'red eye' (36.7% of patients), 'painful white eye' (11.1%) and 'flashes and floaters' (10.2%). A total of 64.1% of patients were managed in optometric practice and 18.9% were referred to the HES; of these, 89.2% had been appropriately referred. First attendances to HES referred by GPs reduced by 26.8% (95% CI -40.5% to -13.1%) in Lambeth and Lewisham compared to Southwark. CONCLUSIONS: The Lambeth and Lewisham MECS demonstrates clinical effectiveness, reduction in hospital attendances and high patient satisfaction and represents a successful collaboration between commissioners, local HES units and primary healthcare providers