Eyecare practitioner perspectives and attitudes towards myopia and myopia management in the UK.

OBJECTIVE: Many children with progressive myopia are still prescribed single-vision correction. An investigation into UK eyecare practitioners' (ECPs) perceptions of myopia management was carried out to ascertain factors which may be limiting its implementation and uptake within clinical practice. METHODS AND ANALYSIS: Online focus groups were held with UK ECPs. Participants were encouraged to discuss their knowledge of the available myopia management options, their perception of how myopia management is being delivered in the UK and any barriers limiting ECPs' prescribing of these management options in practice. The discussions were transcribed and analysed thematically. RESULTS: Focus groups were held with 41 ECPs from primary and secondary eyecare. ECPs felt that provision of myopia management in the UK is variable. Most ECPs believe they have sufficient knowledge, but felt a lack of confidence in decision-making and practical experience. Less experienced ECPs sought more definitive guidance to support their decision-making. ECPs desired clarity on their duty of care obligations and were concerned over possible future litigation if they had not offered, or referred for, myopia management when indicated. The greatest barrier appears to be financial-treatment is expensive and ECPs are uncomfortable communicating this to parents. Many barriers were indicative of systemic problems within UK eyecare, such as commercial pressures, inadequate National Health Service funding and poor public awareness of paediatric eyecare. CONCLUSION: Myopia management is not implemented consistently across the UK. To improve accessibility, changes are required at multiple levels, from individual ECPs through to wider stakeholders in UK eyecare provision.

Investigating target refraction advice provided to cataract surgery patients by UK optometrists and ophthalmologists.

PURPOSE: To determine whether UK optometrists and ophthalmologists provide target refraction advice to patients prior to cataract surgery, and when this should first be discussed. METHODS: Optometrists and ophthalmologists were asked to complete a survey of two clinical vignettes (both older patients with cataract; a pre-operative myope who routinely read without glasses and a patient using a monovision approach), plus multiple choice and short answer questions either using hard copy or online. RESULTS: Responses were obtained from 437 optometrists and 50 ophthalmologists. Optometrists who reported they would provide target refraction advice were more experienced (median 22 years) than those who would leave this to the Hospital Eye Service (median 10 years). The former group reported it was in the patients' best interest to make an informed decision as they had seen many myopic patients who read uncorrected pre-operatively, and were unhappy that they could no longer do so after surgery. Inexperienced optometrists reported that they did not want to overstep their authority and left the decision to the ophthalmologist. The ophthalmologists estimated their percentage of emmetropic target refractions over the last year to have been 90%. CONCLUSION: Currently, some long-term myopes become dissatisfied after cataract surgery due to an emmetropic target refraction that leaves them unable to read without glasses as they did prior to surgery. Although experienced optometrists are aware of this and attempt to discuss this issue with patients, less experienced optometrists tend not to. This suggests that target refraction needs greater exposure in university training and continuing professional development. To provide patients with the knowledge to make informed decisions regarding their surgery, we suggest an agreed protocol within funded direct referral schemes of initial target refraction discussions by optometrists to introduce the idea of refractive outcomes and outline options, with further discussion with the ophthalmologist to clarify understanding.

When is refraction stable following routine cataract surgery? A systematic review and meta-analysis.

PURPOSE: We systematically reviewed the literature to investigate when refraction is stable following routine cataract surgery implanting monofocal intraocular lenses. Current advice recommends obtaining new spectacles 4-6 weeks following surgery. Due to advancements in surgical techniques, we hypothesised that refractive stability would be achieved earlier, which could have major short-term improvements in quality of life for patients. METHODS: Medline, CINAHL, AMED, Embase, Web of Science and the Cochrane Library were searched with key words chosen to find articles, which assessed refraction following uncomplicated cataract surgery. Citation chains and the reference lists of all included papers were searched. Unpublished literature was identified using OpenGrey (www.opengrey.eu). The review considered studies that measured refraction at regular intervals following surgery until stability was achieved. RESULTS: The search identified 6,680 papers. Two reviewers independently screened the abstracts and nine papers were found to fit the criteria, of which five were included in the meta-analysis. The quality of the papers was evaluated using the Methodological Index for Non-Randomised Studies (MINORS) instrument. Meta-analysis of 301 patients' data of spherical, cylindrical and spherical equivalent correction were performed using Review Manager 5 (RevMan 5.3) (https://revman.cochrane.org/). Refraction at 1-week versus the gold standard of 4-weeks showed no significant difference for sphere data (effect size and 95% confidence interval of; ES = 0.00, 95% CI: -0.17, 0.17; p = 1.00), cylindrical data (ES = +0.06; 95% CI: -0.05, 0.17; p = 0.31), and spherical equivalent (ES = -0.01; 95% CI: -0.12, 0.10; p = 0.90). Heterogeneity was non-significant (I2  < 25%) for all refractive elements. Data were similar for 2- versus 4-weeks post-surgery. Acquired data from one study highlighted a small number of patients with very unstable cylindrical corrections at 1-week post-operatively. CONCLUSIONS: No statistical difference was found when comparing sphere, cylindrical and spherical equivalent values at 1- and 4-weeks post cataract surgery. This suggests that new glasses could be provided 1-week after surgery. However, from a clinical perspective, a small number of patients (~7%) from an acquired dataset (N = 72) showed very unstable cylindrical corrections at 1-week. Further work is needed to determine why this is the case and how these patients can be detected.

Development and Validation of the Vision-Related Dizziness Questionnaire.

PURPOSE: To develop and validate the first patient-reported outcome measure (PROM) to quantify vision-related dizziness. Dizziness is a common, multifactorial syndrome that causes reductions in quality of life and is a major risk factor for falls, but the role of vision is not well understood. METHODS: Potential domains and items were identified by literature review and discussions with experts and patients to form a pilot PROM, which was completed by 335 patients with dizziness. Rasch analysis was used to determine the items with good psychometric properties to include in a final PROM, to check undimensionality, differential item functioning, and to convert ordinal questionnaire data into continuous interval data. Validation of the final 25-item instrument was determined by its convergent validity, patient, and item-separation reliability and unidimensionality using data from 223 patients plus test-retest repeatability from 79 patients. RESULTS: 120 items were originally identified, then subsequently reduced to 46 to form a pilot PROM. Rasch analysis was used to reduce the number of items to 25 to produce the vision-related dizziness or VRD-25. Two subscales of VRD-12-frequency and VRD-13-severity were shown to be unidimensional, with good psychometric properties. Convergent validity was shown by moderately good correlations with the Dizziness Handicap Inventory (r = 0.75) and good test-retest repeatability with intra-class correlation coefficients of 0.88. CONCLUSION: VRD-25 is the only PROM developed to date to assess vision-related dizziness. It has been developed using Rasch analysis and provides a PROM for this under-researched area and for clinical trials of interventions to reduce vision-related dizziness.

A Comparison of Spectacles Purchased Online and in UK Optometry Practice.

PURPOSE: To compare spectacles bought online with spectacles from optometry practices. METHODS: Thirty-three participants consisting of single vision spectacle wearers with either a low (N = 12, mean age 34 ± 14 years) or high prescription (N = 11, mean age 28 ± 9 years) and 10 presbyopic participants (mean age 59 ± 4 years) wearing progressive addition lenses (PALs) purchased 154 pairs of spectacles online and 154 from UK optometry practices. The spectacles were compared via participant-reported preference, acceptability, and safety; the assessment of lens, frame, and fit quality; and the accuracy of the lens prescriptions to international standard ISO 21987:2009. RESULTS: Participants preferred the practice spectacles (median ranking 4th, IQR 1-6) more than online (6th, IQR 4-8; Mann-Whitney U = 7345, p < 0.001) and practice PALs (median ranking 2nd, IQR 1-4) were particularly preferred (online 6.5th, IQR 4-9, Mann-Whitney U = 455, p < 0.001). Of those deemed unacceptable and unsafe, significantly more were bought online (unacceptable: online 43/154 vs. practice 15/154, Fisher's exact p = 0.0001; unsafe: online 14/154 vs. practice 5/154, Fisher's exact p = 0.03). CONCLUSIONS: Participants preferred spectacles from optometry practice rather than those bought online, despite lens quality and prescription accuracy being similar. A greater number of online spectacles were deemed unsafe or unacceptable because of poor spectacle frame fit, poor cosmetic appearance, and inaccurate optical centration. This seems particularly pertinent to PAL lenses, which are known to increase falls risk. Recommendations are made to improve both forms of spectacle provision.

Is there a link between dizziness and vision? A systematic review.

PURPOSE: The aim of this study was to systematically review the literature to investigate the link (if any) between vision and dizziness. METHODS: Medline, CINAHL, AMED, Web of Science and The Cochrane Library were searched with keywords chosen to find articles which investigated the causes of dizziness and considered vision as a possible trigger. Citation chaining of all included papers was performed in addition to the hand searching of all reference lists. Unpublished literature was identified using www.opengrey.eu. The review considered studies involving adults which link, measure or attempt to improve any aspect of vision in relation to dizziness. RESULTS: Nine thousand six hundred and eighty one possible references were found, and the abstracts were screened independently by two reviewers to determine if they should be included in the study. Thirteen papers were found which investigated whether dizziness was linked to an assessment of vision. Visual impairment measures were crude and typically self-report, or Snellen visual acuity with little or no measurement details. Five studies found an independent link between dizziness and vision, five found a weak association (typically finding a link when univariate analyses were used, but not when multivariate analyses were used), and three found no association. Studies finding a strong link were usually cross-sectional with a large study population whereas those finding a weak association had relatively small numbers of participants. Studies which did not find an association used a broad definition of dizziness that included the term light-headedness, an unreliable Rosenbaum near visual acuity chart or an unusual categorisation of visual acuity. CONCLUSIONS: This review suggests that dizziness (although likely not 'light-headedness') is linked with poor vision although further studies using more appropriate measures of vision are recommended.

Dizziness, but not falls rate, improves after routine cataract surgery: the role of refractive and spectacle changes.

PURPOSE: To determine whether dizziness and falls rates change due to routine cataract surgery and to determine the influence of spectacle type and refractive factors. METHODS: Self-reported dizziness and falls were determined in 287 patients (mean age of 76.5 ± 6.3 years, 55% females) before and after routine cataract surgery for the first (81, 28%), second (109, 38%) and both eyes (97, 34%). Dizziness was determined using the short-form of the Dizziness Handicap Inventory. Six-month falls rates were determined using self-reported retrospective data. RESULTS: The number of patients with dizziness reduced significantly after cataract surgery (52% vs 38%; χ(2) = 19.14(,) p < 0.001), but the reduction in the number of patients who fell in the 6-months post surgery was not significant (23% vs 20%; χ(2) = 0.87, p = 0.35). Dizziness improved after first eye surgery (49% vs 33%, p = 0.01) and surgery on both eyes (58% vs 35%, p < 0.001), but not after second eye surgery (52% vs 45%, p = 0.68). Multivariate logistic regression analyses found significant links between post-operative falls and change in spectacle type (increased risk if switched into multifocal spectacles). Post-operative dizziness was associated with changes in best eye visual acuity and changes in oblique astigmatic correction. CONCLUSIONS: Dizziness is significantly reduced by first (or both) eye cataract surgery and this is linked with improvements in best eye visual acuity, although changes in oblique astigmatic correction increased dizziness. The lack of improvement in falls rate may be associated with switching into multifocal spectacle wear after surgery.

A method for profiling biometric changes during disaccommodation.

PURPOSE: To demonstrate the application of low-coherence reflectometry to the study of biometric changes during disaccommodation responses in human eyes after cessation of a near task and to evaluate the effect of contact lenses on low-coherence reflectometry biometric measurements. METHODS: Ocular biometric parameters of crystalline lens thickness (LT) and anterior chamber depth (ACD) were measured with the LenStar device during and immediately after a 5 D accommodative task in 10 participants. In a separate trial, accommodation responses were recorded with a Shin-Nippon WAM-5500 optometer in a subset of two participants. Biometric data were interleaved to form a profile of post-task anterior segment changes. In a further experiment, the effect of soft contact lenses on LenStar measurements was evaluated in 15 participants. RESULTS: In 10 adult participants, increased LT and reduced ACD was seen during the 5 D task. Post-task, during fixation of a 0 D target, a profile of the change in LT and ACD against time was observed. In the two participants with accommodation data (one a sufferer of nearwork-induced transient myopia and other a non-sufferer), the post-task changes in refraction compared favorably with the interleaved LenStar biometry data. The insertion of soft contact lenses did not have a significant effect on LenStar measures of ACD or LT (mean change: -0.007 mm, p = 0.265 and + 0.001 mm, p = 0.875, respectively). CONCLUSIONS: With the addition of a relatively simple stimulus modification, the LenStar instrument can be used to produce a profile of post-task changes in LT and ACD. The spatial and temporal resolution of the system is sufficient for the investigation of nearwork-induced transient myopia from a biometric viewpoint. LenStar measurements of ACD and LT remain valid after the fitting of soft contact lenses.

Simultaneous measurement of objective refraction, accommodation response and axial length of the human eye.

PURPOSE: Accurate measurements of ocular biometry and objective refraction are of vital importance to research laboratories working in the area of refractive error development and oculomotor function. A number of commercially available instruments can provide these measurements, and are used in both their intended modes, and with modifications to increase their research utility. A limitation that exists currently is the inability to conduct simultaneous measurements of refractive error or accommodation response, and the axial length of the same eye. In this technical note we provide details of a method to adapt the Zeiss IOLMaster and the Shin-Nippon SRW-5000 infrared optometer to simultaneously measure refraction and axial length. METHODS: The optical modification used to combine the measurement paths of the IOLMaster and SRW-5000 instruments consists of a narrow band-pass filter, and optical relay to extend the working distance of the IOLMaster, and an electronic system to provide synchronisation between the IOLMaster and the SRW-5000 continuous accommodation recording system. The optical modification was tested on model eyes, and on a cohort of 20 human eyes. The combined system was then used to measure accommodation response and axial length simultaneously in a single participant. RESULTS: Inclusion of the optical modification in the IOLMaster pathway induced a 0.004 mm shift in the average measurement of a calibration eye, and an average difference of 0.001 mm for a cohort of human eyes. For the SRW-5000, inclusion of the modified optics induced a +0.15 D shift in the spherical component of refraction measurements made on a model eye, and an average shift of +0.12 D in the spherical component of measurements made on a cohort of human eyes. Simultaneous measurement of accommodation response and axial length in a single participant revealed that a change in stimulus vergence from 0 to 5 D caused an average accommodation response of 3.89 D, and an average transient axial length change of 0.059 mm. CONCLUSIONS: The system described provides a useful method of achieving simultaneous measurements of axial length, objective refraction and accommodation response in a human eye.