Scope of practice of optometrists working in the UK Hospital Eye Service: Second national survey.

PURPOSE: As the landscape in ophthalmology and related commissioning continues to change, there is a pressing need to re-evaluate the current scope of practice of hospital optometrists working within secondary care in the UK. We aim to establish if the skills or services delivered by optometrists have changed to meet varying demands, and to better understand what changes in practice may have arisen as a result of COVID-19. METHOD: A survey developed from that used in 2015 was disseminated to 129 optometry Hospital Eye Service (HES) leads in September 2020, including questions on department workforce; core services; extended roles; procedures undertaken within extended roles; level of autonomy; arrangements for prescribing; training and accreditation, and service changes in response to COVID-19. RESULTS: Ninety responses were received (70% response rate) from within England (76%), Scotland (22%) and Northern Ireland (2%). Whole time equivalents within units ranged from 0.4-79.2 (median of 2.5). In comparison to the 2015 survey, there was an increase in the proportion of units delivering extended roles, with glaucoma (88%) remaining the most common extended role, and new areas of practice in uveitis (21%) and vitreoretinal (13%) services. There was increased use of independent prescribing (67%) in comparison to 18% in 2015 and there was an increase in optometrists delivering laser interventions. In response to COVID-19, optometrists were increasingly delivering telephone consultations and there were new collaborations between primary and secondary care. CONCLUSIONS: Optometrists' scope of practice continues to develop in the HES with an increased variety of roles and an apparent increase in the number of units employing optometrists, often working in roles historically performed by medical practitioners. Such changes appear necessary in recovery and transformation within ophthalmology, alongside wider optometry changes arising at the interface of primary and secondary care.

Scope of practice of optometrists working in the UK Hospital Eye Service: a national survey.

PURPOSE: The role of the optometrist in the Hospital Eye Service (HES) has undergone significant development in recent years to include extended areas of clinical practice more traditionally undertaken by ophthalmologists, commensurate with a growing demand for increased capacity in ophthalmic services. In this report, we present the findings from a national survey of the scope of practice of optometrists working in the UK HES. METHODS: A survey was designed to incorporate questions on the provision of core services before seeking detailed information on the scope of practice within extended roles to include: ophthalmic sub-specialist areas where optometrists currently practice; the undertaking of specific procedures within these services; the relative autonomy of practice within these extended roles; and the training and accreditation requirements for working within extended roles. SurveyMonkey was used to disseminate the survey to the head of optometry in 79 HES units throughout the UK. RESULTS: Responses were received from 70 of the 79 (89%) survey invitations. A substantial majority of respondents (N = 67/70, 96%) indicated that optometrists undertook extended roles. Glaucoma is the leading extended role service provided by optometrists (92% of respondents providing extended role services), with roles in macula (71%), medical retina/diabetes (67%), cataract (55%) and corneal services (55%) also being relatively common. A wide variety of clinical procedures or interventions are undertaken as part of these services, which for a small number of optometrists now also includes the undertaking of specific laser procedures. There is evidence for a significant degree of autonomy within these extended roles. The primary mode of training is an 'apprentice' model, incorporating sessions worked under supervision in ophthalmology clinics. Methods of accreditation for optometric participation in extended role services are varied. CONCLUSIONS: While optometrists working within the UK HES continue to undertake the traditional clinical roles of refraction, clinically necessary contact lenses, and low vision rehabilitation, it is clear that these professionals now undertake a wide range of extended clinical roles, with a transformed scope of practice now incorporating diverse roles traditionally undertaken by medical practitioners.

Optical quality and visual performance with customised soft contact lenses for keratoconus.

PURPOSE: This study investigated how aberration-controlling, customised soft contact lenses corrected higher-order ocular aberrations and visual performance in keratoconic patients compared to other forms of refractive correction (spectacles and rigid gas-permeable lenses). METHODS: Twenty-two patients (16 rigid gas-permeable contact lens wearers and six spectacle wearers) were fitted with standard toric soft lenses and customised lenses (designed to correct 3rd-order coma aberrations). In the rigid gas-permeable lens-wearing patients, ocular aberrations were measured without lenses, with the patient's habitual lenses and with the study lenses (Hartmann-Shack aberrometry). In the spectacle-wearing patients, ocular aberrations were measured both with and without the study lenses. LogMAR visual acuity (high-contrast and low-contrast) was evaluated with the patient wearing their habitual correction (of either spectacles or rigid gas-permeable contact lenses) and with the study lenses. RESULTS: In the contact lens wearers, the habitual rigid gas-permeable lenses and customised lenses provided significant reductions in 3rd-order coma root-mean-square (RMS) error, 3rd-order RMS and higher-order RMS error (p ≤ 0.004). In the spectacle wearers, the standard toric lenses and customised lenses significantly reduced 3rd-order RMS and higher-order RMS errors (p ≤ 0.005). The spectacle wearers showed no significant differences in visual performance measured between their habitual spectacles and the study lenses. However, in the contact lens wearers, the habitual rigid gas-permeable lenses and standard toric lenses provided significantly better high-contrast acuities compared to the customised lenses (p ≤ 0.006). CONCLUSIONS: The customised lenses provided substantial reductions in ocular aberrations in these keratoconic patients; however, the poor visual performances achieved with these lenses are most likely to be due to small, on-eye lens decentrations.

Visual performance and optical quality with soft lenses in keratoconus patients.

PURPOSE: To assess visual performance and ocular aberrations in keratoconic patients using toric soft contact lenses (SCL), rigid-gas-permeable (RGP) contact lenses and spectacle lens correction. METHODS: Twenty-two keratoconus patients (16 RGP lens wearers and six spectacle wearers) were fitted with toric SCL. Ocular aberrations were measured with and without the patient's habitual RGP lenses and with the SCL in place. In the spectacle wearers, aberrations were measured with and without the SCL. Visual performance (high- and low-contrast visual acuity) was evaluated with the patient's habitual correction and with the SCL. RESULTS: In the RGP lens wearers both the habitual lenses and the toric SCL significantly reduced coma, trefoil, 3rd-order, 4th-order cylinder and higher-order root-mean-square (RMS) aberrations (p ≤ 0.015). In the spectacle wearers the toric SCL significantly reduced coma, 3rd-order and higher-order RMS aberrations (p ≤ 0.01). The patients' habitual RGP lenses gave better low-contrast acuity (p ≤ 0.006) compared to the toric SCL; however, no significant difference was found between lens types for high-contrast acuity (p = 0.10). In the spectacle wearers no significant differences in visual performance measurements were found between the patients' spectacles and the toric SCL (p ≥ 0.06). CONCLUSION: The results show that RGP lenses provided superior visual performances and greater reduction of 3rd-order aberrations compared to toric SCL in this group of keratoconic patients. In the spectacle-wearing group, visual performance with the toric SCL was found to be comparable to that measured with spectacles. Nevertheless, with the exception of spherical aberration, the toric SCL were successful in significantly reducing uncorrected higher-order aberrations.

Agreement in clinical decision-making between independent prescribing optometrists and consultant ophthalmologists in an emergency eye department.

BACKGROUND: The specialty-registration of independent prescribing (IP) was introduced for optometrists in 2008, which extended their roles including into acute ophthalmic services (AOS). The present study is the first since IP's introduction to test concordance between IP optometrists and consultant ophthalmologists for diagnosis and management in AOS. METHODS: The study ran prospectively for 2 years at Manchester Royal Eye Hospital (MREH). Each participant was individually assessed by an IP optometrist and then by the reference standard of a consultant ophthalmologist; diagnosis and management were recorded on separate, masked proformas. IP optometrists were compared to the reference standard in stages. Cases of disagreement were arbitrated by an independent consultant ophthalmologist. Cases where disagreement persisted after arbitration underwent consensus-review. Agreement was measured with percentages, and where possible kappa (Κ), for: diagnosis, prescribing decision, immediate management (interventions during assessment) and onward management (review, refer or discharge). RESULTS: A total of 321 participants presented with 423 diagnoses. Agreement between all IP optometrists and the staged reference standard was as follows: 'almost perfect' for diagnosis (Κ = 0.882 ± 0.018), 'substantial' for prescribing decision (Κ = 0.745 ± 0.034) and 'almost perfect' for onward management (0.822 ± 0.032). Percentage-agreement between all IP optometrists and the staged reference standard per diagnosis was 82.0% (CI 78.1-85.4%), and per participant using stepwise weighting was 85.7% (CI 81.4-89.1%). CONCLUSIONS: Clinical decision-making in MREH's AOS by experienced and appropriately trained IP optometrists is concordant with consultant ophthalmologists. This is the first study to explore and validate IP optometrists' role in the high-risk field of AOS.

An evaluation of corneal nerve morphology and function in moderate keratoconus.

PURPOSE: To investigate corneal nerve morphology and corneal sensitivity in keratoconus. METHODS: The central cornea of 13 subjects with keratoconus and 13 age-matched control subjects was assessed using in vivo confocal microscopy and corneal aesthesiometry. RESULTS: Significant differences in corneal nerve fibre density were found between the subjects with keratoconus and the control subjects (keratoconus versus control; 1018.3+/-489.6 microm versus 1820.7+/-789.5 microm; p = 0.006). The mean diameter of nerve fibres in the stroma was found to be greater in subjects with keratoconus compared to control subjects (keratoconus versus control; 10.2+/-4.6 microm versus 5.5+/-1.9 microm; p = 0.007). The orientation of corneal nerve fibres in the subjects with keratoconus appeared to be altered from the predominantly vertical orientation seen in the control subjects. Corneal touch threshold was found to be similar in the two groups, although the subjects with keratoconus using contact lens correction had reduced corneal sensitivity compared to the contact lens-wearing control subjects (keratoconus with contact lenses versus controls with contact lenses; 1.18+/-0.19 g/mm2 versus 0.98+/-0.05 g/mm2; p = 0.03). CONCLUSION: This study reveals significant reductions in nerve density in the keratoconic cornea. The thickened stromal nerve fibres observed in the keratoconic corneas may explain why prominent corneal nerves are often seen using slit lamp biomicroscopy in keratoconic patients.

Scleral contact lens management of bilateral exposure and neurotrophic keratopathy.

We report an interesting case of therapeutic scleral lens management of bilateral exposure and neurotrophic keratopathy resulting from bilateral cranial nerve (CN) palsies including V, VI and VII, which caused lagophthalmos and anaesthetic corneas. Subsequent development of severe exposure keratitis with vascularisation and keratinisation of the inferior cornea was previously treated with intensive ocular lubrication, botulinum toxin injections to the upper eyelid levator muscle, temporary tarsorrhophies, bilateral amniotic membrane grafts, punctal plugs, lid taping, gold eyelid weights and soft bandage contact lenses. Corneal integrity was re-established but visual acuity remained significantly compromised by corneal vascularisation, scarring and keratin deposits. Visions on presentation to the contact lens department were R 1.90 logMAR, L 1.86 logMAR. Therapeutic, high Dk, non-fenestrated, saline filled, scleral lenses were fitted. Daily wear of these lenses have protected and hydrated the cornea, enabling corneal surface recovery whilst retaining visual and social function. The visual acuities 6 months post-scleral fitting with lenses in situ are R 0.90 logMAR and L logMAR 0.70.

Reduction in corneal volume with severity of keratoconus.

PURPOSE: To compare the corneal volume in keratoconic and normal eyes to improve our understanding of the tissue distribution associated with the disease. MATERIALS AND METHOD: The Oculus Pentacam tomographer (Oculus Inc., Wetzlar, Germany) was used to analyze the corneal volume contained within discs with diameters of 3, 5, 7, and 10 mm in 21 patients with keratoconus and 21 matched healthy control subjects. RESULTS: Corneal volume was significantly decreased in the keratoconus group (keratoconus vs. control group: 3.44 ± 0.39 vs. 4.05 ± 0.29 mm(3), 10.34 ± 0.95 vs. 11.79 ± 0.84 mm(3), 22.80 ± 1.73 vs. 25.26 ± 1.74 mm(3), and 57.17 ± 3.94 vs. 61.90 ± 4.12 mm(3) for the 3-, 5-, 7-, and 10-mm diameter discs, respectively; p < 0.001). As the corneal disc diameter analyzed increased, fewer differences were found between the control corneas and keratoconic corneas at different stages of the disease. Within the 3-mm and 5-mm diameter discs, significant differences were detected between the control group, moderate keratoconus, and the severe keratoconus groups (p < 0.05). However, within the 10-mm discs, differences were only detected between the control group and the severe keratoconus group (p = 0.005). CONCLUSIONS: Corneal volume was significantly decreased in keratoconus, particularly in the central and paracentral area. The decrease in corneal volume in moderate and severe keratoconus as detected by the Pentacam tomographer, may be explained by loss of corneal tissue. In the early stages of the disease, the altered metabolic activity may cause tissue stretching and, as the disease progresses, this stretching is then accompanied by tissue loss.

A biometric investigation of ocular components in amblyopia.

The aim of this study was to investigate the ocular parameters and their contribution to total axial length, and any inter-ocular differences when compared to the fellow non-amblyopic eye, in a population of paediatric amblyopes. Inter-ocular differences in visual acuity, refractive error, corneal curvature, anterior chamber depth and their contribution to total axial length were analysed in four populations: adult controls (n=26), paediatric controls (n=24), paediatric strabismic amblyopes (n=18) and paediatric anisometropic amblyopes (n=27). In the two control groups, there were small inter-ocular differences between the components, none of which were statistically or clinically significant. Anisometropic amblyopic eyes were found to have statistically and clinically significant differences in refractive error, crystalline lens power, vitreous chamber depth and total axial length when compared to the fellow eye. Anterior and vitreous chamber depths, when expressed as a percentage of the anterior and vitreous chambers in the non-amblyopic fellow eye, were approximately 95% of the size. When parameters were normalised by expressing as a percentage of total axial length, the contribution of the anterior chamber, crystalline lens and vitreous chamber to total axial length in both eyes were comparable, suggesting that all components of the anisometropic amblyopic eye are proportionately reduced in size. The strabismic amblyopic eyes were in the main isometropic. There were however statistically significant differences in anterior chamber depth, crystalline lens power, vitreous chamber depth and total axial length, but not in crystalline lens thickness. When the components were expressed as a percentage of the component in the non-amblyopic fellow eye, the anterior and vitreous chambers were approximately 90% of the size of the fellow non-amblyopic eye and made a significantly smaller contribution to total axial length when normalised. Crystalline lens thickness contributed significantly more to the total axial length in a strabismic eye. This suggests that, unlike control eyes or anisometropic amblyopic eyes, the strabismic eye is physically, though not proportionately, reduced in size.

Corneal nerve structure and function in keratoconus: a case report.

PURPOSE: To investigate corneal nerve structure and function in a 24-year-old patient with keratoconus and prominent corneal nerves. METHODS: Corneal nerve appearance was assessed by using a corneal confocal microscope, and corneal nerve function was assessed by using a Cochet-Bonnet aesthesiometer. Findings were compared to those of an age-matched control subject without keratoconus. RESULTS: The patient with keratoconus was found to have thicker nerve fiber bundles in the stroma (keratoconus vs. control, 9.8 +/- 5.0 microm vs. 5.4 +/- 2.7 microm) and reduced nerve fiber density in the subepithelial plexus (keratoconus vs. control, 269.7 +/- 145.6 microm vs. 1,258 +/- 254.8 mum) compared to the control subject. The patient with keratoconus was found to have reduced corneal sensitivity compared to the control subject (keratoconus vs. control 0.39 gr/mm2 vs. 1.59 gr/mm2). CONCLUSIONS: Corneal confocal microscopy proved to be a useful in vivo technique for assessing corneal nerve structure in this patient with keratoconus. Although the total number of stromal nerve fiber bundles was reduced in the patient with keratoconus versus the control subject, the increased tortuosity and increased nerve fiber diameter may explain why the corneal nerves appear more visible in this patient with keratoconus.