BCLA CLEAR Presbyopia: Management with contact lenses and spectacles.

This paper seeks to outline the history, market situation, clinical management and product performance related to the correction of presbyopia with both contact lenses and spectacles. The history of the development of various optical forms of presbyopic correction are reviewed, and an overview is presented of the current market status of contact lenses and spectacles. Clinical considerations in the fitting and aftercare of presbyopic contact lens and spectacle lens wearers are presented, with general recommendations for best practice. Current options for contact lens correction of presbyopia include soft simultaneous, rigid translating and rigid simultaneous designs, in addition to monovision. Spectacle options include single vision lenses, bifocal lenses and a range of progressive addition lenses. The comparative performance of both contact lens and spectacle lens options is presented. With a significant proportion of the global population now being presbyopic, this overview is particularly timely and is designed to act as a guide for researchers, industry and eyecare practitioners alike.

Using big data to understand interest in myopia.

SIGNIFICANCE: Popularity of publicly searched myopia terminologies is reported, for example, myopia control over myopia management and myopia over nearsighted or shortsighted. Insights are also provided for searches on specific myopia control interventions. The findings offer an evidence-based starting point for public messaging and communications by clinicians, policymakers, and other industry leaders. PURPOSE: Public understanding of myopia can be difficult to ascertain for clinicians. Although small-scale studies provide valuable snapshots of data, findings tend to be population-specific and thus difficult to extrapolate to global audiences. In this study, big data were used to provide a more comprehensive depiction of global market interest in myopia. METHODS: Google Trends data were used to analyze searches relating to myopia between January 2004 and August 2023. Data extracted were related to use of the terms myopia control and myopia management, with further searches executed for common myopia control interventions: orthokeratology, contact lenses, atropine, and glasses. Analysis into the search interest of other refractive error states, hyperopia and astigmatism, was also undertaken along with alternative terms that may be used to describe myopia. Where relevant, search trends were considered worldwide, by country, and over time. RESULTS: Myopia was a more popular search term than common layman alternatives such as nearsighted or shortsighted. Myopia control was found to be more popular than myopia management, and of the specific myopia interventions, atropine was most popular. Compared with astigmatism and hyperopia, relative search volumes were greatest for myopia, on average accounting for approximately 50% of the relative search volume at the country level. CONCLUSIONS: The differences identified in both popularity of myopia-related search terms and specific interventions may provide the basis for improvements in public messaging and facilitate patient-practitioner communication.

Current approaches to soft contact lens handling training - Global perspectives.

PURPOSE: All neophyte contact lens wearers require training on how to handle contact lenses. Currently, almost no published information exists describing the most common approaches used by those involved in such training in soft contact lens wearers. This study aimed to gather information on the approaches taken by those conducting this training worldwide. METHODS: An online survey was created in English and translated to Spanish and distributed internationally via social media, conference attendees, and professional contacts. The anonymous survey included information on workplace setting of respondents, information about the typical approaches used for application and removal of soft contact lenses, length of the appointment, and success rate with their approach. Survey responses were received between May 2021 and April 2022. RESULTS: A total of 511 individuals completed the survey and responses were received from 31 countries with 48.7% from the UK. The most common approach taught for application was to have the patient hold the upper eyelashes (84.7%) and to hold the lower eyelid with the same hand as the lens (89.4%). Lenses were applied directly to the cornea by 57.7% of the respondents. The most common approach taught for lens removal was to drag the lens inferiorly from the cornea prior to removal (49.3%). Most respondents did not use videos to aid the teaching appointment (62.0%); however, they felt that their approach was successful in most cases (90). Application and removal training sessions lasted a median of 30 min and contact lenses were typically dispensed after the instructor witnessing successful application and removal three times. CONCLUSION: Various methods are adopted globally for training of application and removal of soft contact lenses, with many advising a patient-specific approach is required for success. The results of this survey provide novel insights into soft contact lens handling training in clinical practice.

Evidence-based teaching in contact lenses education: Teaching and learning strategies.

INTRODUCTION: Contact lens (CL) practice is an ever-changing field with clinical knowledge, techniques and equipment continuously evolving. These new developments are backed with clinical trials and research to ensure that practitioners feel confident that there is an evidence base to support these advances. Evidence-based practice is now a crucial part of CL practice, and its importance also filters down to CL education. For example, lectures are one of the most popular tools for an educator but, is standing at the front of a lecture theatre full of students a more effective way of teaching than providing the same material for students to read by themselves? What evidence exists specific to CL education? METHOD: An expert panel of educators completed a comprehensive literature review of current evidence of teaching methods in CL training, or if not available then what can be learnt from other health care professional training that could be potentially applicable to CL education. RESULTS: Due to the amount of evidence available in the overall subject area relating to healthcare education, the initial plan of compiling evidence into one narrative review paper was discarded in favour of producing two linked papers. Here, the first paper details definitions of terminology, and also teaching methods. The second paper focuses on assessment and specific clinical training required to attain CL practice competency. In this first paper, no direct evidence of the spreading and benefit of new education strategies evidence such as flipped classrooms, spaced learning, test-enhanced learning, group work, CBL, PBL, TBL, and reflective practice in CL education was found. The only technique that was widely used in the CL field was case reports and the group discussion of them. Nevertheless, the authors found a consensus of opinion from other disciplines that are transferable to CL teaching and could help students meet the intended learning outcomes. CONCLUSION: There is a small amount of evidence supporting CL education, but most of this seems to be related to the practical element of the training. However, there is a lot of evidence in the field of healthcare education from related disciplines which provides additional but important learning tools that may be effectively implemented in CL education.

The impact of COVID-19 on soft contact lens wear in established European and US markets.

PURPOSE: To characterise changes in soft contact lens wearing habits during the COVID-19 pandemic. METHODS: A detailed online questionnaire was circulated to individuals aged 40-70 years, during the period April to May 2021. Data sampling took place in the United Kingdom (UK), United States of America (USA), Netherlands, Germany, France, Spain and Italy. Only data pertaining to individuals who were soft contact lens wearers were included. Data were extracted for questions relating to contact lens wearing habits pre- and during the COVID-19 pandemic, and expectations for future lens wear beyond the pandemic. RESULTS: Seven-hundred and twenty-eight individuals were identified as soft contact lens wearers of which six-hundred and nineteen wore a combination of contact lenses and spectacles. Most respondents indicated contact lens wear times had either remained the same (57.3%) or increased (9.8%) during the pandemic. The country with the greatest proportion of respondents decreasing wear time during COVID-19 was the UK (45.3%), and the least in the Netherlands (20.0%). The primary cause of decreased lens wear was attributed to leaving the home less often (70.0%), and the second most common reason due to concerns about hygiene (10.8%). Most respondents (83.9%), however, expressed a desire to return to pre-pandemic wear times once the pandemic was over. CONCLUSIONS: Practitioner concerns about contact lens market recovery ought to be assuaged by the survey outcomes which show most individuals to have maintained lens wear during the pandemic. In view of the continued lens wear, as and when restrictions ease, ECPs may wish to encourage patients to return for routine check-ups that may have been missed due to the pandemic.

Exploring contact lens opportunities for patients above the age of 40 years.

PURPOSE: Contact lenses offer a good option for patients with presbyopia, especially with improved optical designs available in modern multifocal contact lenses. Due to the ageing population there is good opportunity to increase contact lens penetration by managing these patients better. However, multifocal contact lenses achieve low penetration in the market. METHODS: A questionnaire was administered to people aged above 40 years, to investigate their perceptions of contact lenses for presbyopia. Only people, with presbyopia, who were existing contact lens wearers or willing to try contact lenses were included. Participants were recruited from United Kingdom (UK), United States of America (USA), Netherlands, Germany, France, Spain and Italy. RESULTS: Data from 1540 participants above the age of 40 years was collected, 57.9% were females and 42.1% males. Overall, 50.8% of the participants wore contact lenses, but contact lens wear was less common amongst older participants. Some data supported earlier studies, such as 6.1% wore gas permeable lenses. However, only 25% of the contact lens wearers used multifocal contact lenses. The reasons the participants wanted to wear contact lenses were similar to younger patient such as sports or cosmesis reasons. Reasons why participants had dropped out of contact lenses included discomfort and dry eye related issues. Poor visual performance with contact lenses was a reason to dropout of contact lenses for the older participants. CONCLUSIONS: The study highlights some failings by eye care practitioners in the management of patients with presbyopia. It seems that patients of this age group are seeking suggestions and recommendations from their eye care practitioner including upgrading contact lenses and dual wear options. The day-to-day problems encountered by the contact lens wearers in this study seem to be, in the main, things that could be easily tackled by additional counselling and instruction from the eye care practitioners.

Fast versus gradual adaptation of soft monthly contact lenses in neophyte wearers.

AIM: To determine if a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone hydrogel reusable disposable contact lenses. METHOD: Across four sites, 74 neophytes (18-28 years) were randomly assigned to a reusable lens cleaned nightly with Opti-Free® Puremoist® multi-purpose contact lens solution: Proclear® (hydrogel) or Biofinity® (silicone hydrogel) and an adaptation schedule: fast (10 h wear from the first day) or gradual (4 h on the first day, increasing their wear time by 2 h on each subsequent day until they had reached 10 h). Masked investigators graded ocular surface physiology and non-invasive tear breakup time (NIBUT) and a range of comfort, vision and lens handling subjective ratings (0-100 visual analogue scales) were recorded at the baseline visit and after 10 h of lens wear, 4-6 days and 12-14 days after lens fitting. Subjective scores were also repeated after 7 days. RESULTS: There was no difference (p > 0.05) in ocular surface physiology or NIBUT between fast and gradual adaptation groups at any time point in either lens type with the exception of increased corneal staining (p = 0.019) in the silicone hydrogel fast adaptation group after 4-6 days, but was similar by 12-14 days. Subjective scores were also similar across the visits and lens types with the exception of 'lens awareness' (p = 0.019) which was less in the gradual versus the fast adaptation silicone hydrogel lens group at 12-14 days. CONCLUSION: There seems to be no clinical benefit for recommending a gradual adaptation period in new wearers fitted with modern soft reusable disposable contact lenses. The findings of this work add to a growing body of evidence suggesting that such advice is unnecessary in regular soft contact lens wear, which has important ramifications for the initial clinical management of these patients.

CLEAR - Evidence-based contact lens practice.

Evidence-based contact lens -->practice involves finding, appraising and applying research findings as the basis for patient management decisions. These decisions should be informed by the strength of the research study designs that address the question, as well as by the experience of the practitioner and the preferences and environment of the patient. This reports reviews and summarises the published research evidence that is available to inform soft and rigid contact lens history and symptoms taking, anterior eye health examination (including the optimised use of ophthalmic dyes, grading scales, imaging techniques and lid eversion), considerations for contact lens selection (including the ocular surface measurements required to select the most appropriate lens parameter, lens modality and material selection), evaluation of lens fit, prescribing (teaching self-application and removal, adaptation, care regimen and cleaning instructions, as well as -->minimising risks of lens wear through encouraging compliance) and an aftercare routine.

The effect of the COVID-19 pandemic on working practices of UK primary care optometrists.

PURPOSE: In late 2019, a new coronavirus capable of infecting humans, SARS-CoV-2, was identified in Wuhan, China. The resultant respiratory disease was subsequently named COVID-19. In March 2020, in response to the COVID-19 pandemic, primary care optometry practices only remained open to deliver essential or emergency eye care. This study aimed to characterise the experiences of United Kingdom (UK)-based primary care optometrists during the COVID-19 pandemic. METHODS: An email invitation to participate in an online cross-sectional survey was sent to 3000 UK-based, currently practicing members of The College of Optometrists (UK). Responses to the structured questionnaire were analysed using descriptive statistics, including frequencies, means and standard deviations. Frequency analyses were used to evaluate items with multiple responses. Free-text responses were examined using thematic analyses. RESULTS: After data cleaning, a total of 1250 responses remained. Sixty-three percent were female, 70% self-identified as being of white ethnicity and 78% were based in England. During the first national lockdown, over half of all respondents were involved with the provision of remote consultations for emergency/urgent care. The majority felt 'very'/'moderately' comfortable conducting remote consultations, but 66% felt professional liability was increased. Forty percent were involved in the provision of face-to-face consultations. Eye-health and vision-related problems were the most commonly reported patient issues during both remote and face-to-face consultations, while contact-lens related problems were the least. Thematic analysis of the responses showed several challenges adjusting to the pandemic (e.g., working safely), but also some potential benefits (e.g., increased skills). CONCLUSIONS: The findings provide an overview of changes to optometric practice in the UK during the COVID-19 pandemic. The results may be used to inform the development of professional guidance and facilitate resource allocation for safe and effective eye care during this and any future pandemics.

Intra- and Inter-Model Variability of Light Detection Using a Commercially Available Light Sensor.

The veracity of claims made by researchers and clinicians when reporting the impact of lighting on vision and other biological mechanisms is, in part, reliant on accurate and valid measurement devices. We aim to quantify the intra- and inter-watch variability of a commercially available light sensor device which has been widely used in vision and other photobiological research. Intra- and inter-watch differences were investigated between four Actiwatch Spectrum Pro devices. The devices were used to obtain measurements on two separate occasions, under three different controlled light conditions; the Gretag Macbeth Judge II lightbox was used to produce Simulated Daylight (D65), Illuminant A (A) and Cool White Fluorescent (CWF) lighting. Significant inter-watch differences were noted when considering tricolour (red, green, blue) and the white sensor outputs under each of the three illuminants (p < 0.01). A significant interaction was also found between tricolour sensor and watch used (p < 0.01). Intra-watch differences were noted for the tricolour and for the white sensor outputs under the three illuminants (≤0.05), for all but one watch which showed no significant intra-watch difference for the white 'sensor output' under the D65 illuminant. Use of spectral sensitivity devices is an evolving field. Before drawing causal relationships between light and other biological processes, researchers should acknowledge the limitations of the instruments used, their validation, and the resultant data. The outcomes of the study indicate caution must be exercised in longitudinal data collection and the mixing of watches amongst study participants should be avoided.

Open versus closed view autorefraction in young adults.

PURPOSE: While there are numerous studies comparing open-view autorefractors to subjective refraction or other open-view autorefractors, most studies between closed and open-view autorefraction tend to focus on children rather than young adults. The aim of this study was to determine the concordance in non-cycloplegic refractive error between two modern objective autorefractors: the closed-view monocular Topcon TRK-2P and the binocular open-view Grand Seiko WR-5500. METHODS: Fifty young adults aged 20-29 years (mean age 22 ±â€¯1.6 years) underwent non-cycloplegic autorefraction using the Grand Seiko WAM-5500 (open view) and Topcon TRK-2P (closed-view) autorefractors on both eyes. Findings were expressed as the isolated spherical component and were also converted from clinical to vector notation: Mean Spherical Error (MSE) and the astigmatic components J0 and J45. RESULTS: Mean MSE ±â€¯SD was -1.00 ±â€¯2.40D for the Grand Seiko WAM-5500 compared to -1.23 ±â€¯2.29D for the Topcon TRK-2P. Up to seventy-six percent of the cohort had mean spherical errors from the Topcon TRK-2P which fell within ±0.50D of the Grand Seiko reading and 58% fell within ±0.25D. Mean differences between the two instruments were statistically significant for all components (J0, spherical, and MSE) (p < 0.01), except J45 (p > 0.05). CONCLUSIONS: The differences in non-cycloplegic MSE between these two instruments are small, but statistically significant. From a clinical perspective the Topcon TRK-2P may serve as a useful starting point for subjective refraction, but additional work is needed to help further minimise differences between the instruments.

Could telehealth help eye care practitioners adapt contact lens services during the COVID-19 pandemic?

The COVID-19 pandemic has necessitated government-imposed restrictions on social interactions and travel. For many, the guidance has led to new ways of working, most notably a shift towards working remotely. While eye care practitioners (ECPs) may continue to provide urgent or emergency eye care, in many cases the travel restrictions present a unique challenge by preventing conventional face-to-face examination. Telephone triage provides a useful starting point for establishing at-risk and emergency patients; but patient examination is central to contact lens patient care. The indeterminate period over which conventional practice will be suspended, and the risk that resumption of 'normal' practice could be impeded by a potential secondary peak in COVID-19 cases, hastens the need for practitioners to adapt their delivery of eyecare. Specifically, it is prudent to reflect upon supportive evidence for more comprehensive approaches to teleoptometry in contact lens practice. Smartphone based ocular imaging is an area which has seen considerable growth, particularly for imaging the posterior eye. Smartphone imaging of the anterior eye requires additional specialised instrumentation unlikely to be available to patients at home. Further, there is only limited evidence for self-administered image capture. In general, digital photographs, are useful for detection of gross anterior eye changes, but subtle changes are less discernible. For the assessment of visual acuity, many electronic test charts have been validated for use by practitioners. Research into self-administered visual acuity measures remains limited. The absence of a comprehensive evidence base for teleoptometry limits ECPs, particularly during this pandemic. Knowledge gaps ought to be addressed to facilitate development of optometry specific evidence-based guidance for telecare. In particular, advances in ocular self-imaging could help move this field forwards.

Optimising subjective anterior eye grading precision.

PURPOSE: To establish the optimum grading increment which ensured parity between practitioners while maximising clinical precision. METHODS: Second year optometry students (n = 127, 19.5 ± 1.4 years, 55 % female) and qualified eye care practitioners (n = 61, 40.2 ± 14.8 years, 52 % female) had 30 s to grade each of bulbar, limbal and palpebral hyperaemia of the upper lid of 4 patients imaged live with a digital slit lamp under 16× magnification, diffuse illumination, with the image projected on a screen. The patients were presented in a randomised sequence 3 times in succession, during which the graders used the Efron printed grading scale once to the nearest 0.1 increment, once to nearest 0.5 increment and once to the nearest integer grade in a randomised order. Graders were masked to their previous responses. RESULTS: For most grading conditions less than 20 % of clinicians showed a ≤0.1 difference in grade from the mean. In contrast, more than 50 % of the student graders and 40 % of experienced graders showed a difference in grade from the mean within 0.5 for all conditions under measurement. Student precision in grading was better with both 0.1 and 0.5 grading increments than grading to the nearest unit, except for limbal hyperaemia where they performed more accurately with 0.5 unit increment grading. Limbal grading precision was not affected by grading step increment for experienced practitioners, but 0.1 and 0.5 grading increments were both better than the 1.0 grading increment for bulbar hyperaemia and the 0.1 grading increment was better than the 0.5 grading increment and both were better than the 1.0 grading increment for palpebral hyperaemia. CONCLUSION: Although narrower interval scales maximise the ability to detect smaller clinical changes, the grading increment should not exceed one standard deviation of the discrepancy between measurements. Therefore, 0.5 grading increments are recommended for subjective anterior eye physiology grading (limbal, bulbar and palpebral redness).

Characterisation of internal, refractive, and corneal astigmatism in a UK university student population.

PURPOSE: There is a clear benefit in defining internal (IA) and corneal astigmatic error (CA) prior to surgical and other refractive interventions, such as orthokeratology, to minimise risk of unsatisfactory refractive outcomes. Such data would also be of relevance to broader areas of ophthalmic care such as spectacle dispensing and other types of rigid lens fitting. This study offers a detailed characterisation of astigmatic error in a group of university students and specifically investigates compensation of corneal astigmatism by the eye's internal optics. METHODS: For 176 young-adult participants, objective measurements of refractive error were obtained using the open-view Grand Seiko WAM-5500 autorefractor; corneal curvature and axial length were measured using the Aladdin biometer. Clinical measurements of corneal and refractive astigmatism were converted into vector components J0 and J45; followed by an assessment of corneal astigmatism compensation. RESULTS: Mean total refractive astigmatism (RA), CA, and IA were 0.24 ± 0.32D, 0.46 ± 0.27D and -0.21 ± 0.25D respectively for J0 and -0.05 ± 0.20D, 0.01 ± 0.16D, and -0.06 ± 0.18D for J45. Significant linear correlations were noted between RA, CA, and IA for both J0 and J45 (P < 0.01). A significant linear regression was also noted between axial length and J45 RA and IA, but not CA. Levels of full compensation were low, 7% and 9% for J0 and J45 respectively, however, a complete absence of compensation was also uncommon particularly for J45 (2%). CONCLUSIONS: In general, partial compensation for corneal astigmatism by the eye's internal optics is noted, but it is unclear whether this is an active compensatory mechanism. Further, larger scale, studies would be required to characterise differences in corneal astigmatic compensation with respect to ethnicity.

Changes in forward light scatter parameters as a function of refractive error in young adults.

BACKGROUND/AIMS: Some aspects of visual performance worsen with increasing myopia. Whilst the underlying causes are not always clear, reduction in retinal image quality is often attributed to structural changes in the posterior myopic eye. Forward light scatter, originating principally from the cornea and lens, is known to produce veiling glare which subsequently reduces retinal image contrast. It is therefore of interest to investigate whether forward light scatter varies with refractive error. METHODS: Thirteen young-adult subjects (18-25 years), with mean spherical errors (MSE ± sd, D) RE, - 1.69 ± 2.02 (range 0.38 to - 4.75); LE, - 1.91 ± 1.94 (range 0.50 to - 4.63) underwent binocular assessment of forward light scatter using the AVOT light scatter test. Five glare annuli, with effective eccentricities ranging from 2 to 10°, were used to estimate parameters, k and n, which define the light scatter function of the eye. These were then used to calculate the area under the light scatter function (k') and the total volume of light scatter (k″). RESULTS: Significant correlation was found between increasing myopia and k' values (RE, p < 0.05; r = 0.64; LE, p < 0.05, r = 0.66). Neither the 'volume' of light scatter (k″), the parameter, n, which controls the angular distribution of light scatter, or the straylight parameter constant, k, were significantly correlated with refractive error (p > 0.05 for both eyes). Axial length was also not correlated with any of the light scatter parameters measured. CONCLUSION: The preliminary data from this study provide evidence that some light scatter parameters may be correlated with refractive error. Further studies are needed to characterize how changes in the anterior media of the eye, and inclusion of a wider range of refractive errors, may affect forward light scatter.

Fast versus gradual adaptation of soft daily disposable contact lenses in neophyte wearers.

PURPOSE: Despite the widespread practice of gradually adapting all new soft contact lens wearers (neophytes), there is little evidence-based research underpinning such practice. This work determined if a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone-hydrogel daily disposable contact lenses. METHOD: At four sites, neophytes (19-32 years) were randomly assigned to an adaptation schedule: fast (10 h wear from the first day) or gradual (4 h on the first day, increasing their wear-time by 2 h on each subsequent day until they had reached 10 h) with hydrogel (n = 24 fast; n = 21 gradual) or silicone-hydrogel (n = 10 fast; n = 10 gradual) contact lenses. Masked investigators graded ocular surface physiology and non-invasive tear breakup time (NIBUT). A range of subjective scores (using 0-100 visual analogue scales) were recorded at the initial visit and after 10 h of lens wear, 4-6 days and 12-14 days after initial fitting. Subjective scores were also repeated after 7 days. RESULTS: There was no difference (p > 0.05) in ocular surface physiology between the fast and gradual adaptation groups at any time point in either lens type. NIBUT was similar at all time points for both adaptation groups in both lens types with the exception that the gradual adaptation silicone-hydrogel wearers had a slightly longer NIBUT (p = 0.007) than the fast adaptation group at 12-14 days. Subjective scores were also similar across the visits and lens types with the exception of 'lens awareness' and 'ease of lens removal' which were better (p < 0.05) in the fast compared with the gradual adaptation hydrogel lens group at day 7. Additionally, 'end-of-day discomfort' was better (p = 0.02) in the fast compared with the gradual adaptation hydrogel lens group at 12-14 days. CONCLUSION: There appears to be no benefit in daily disposable soft contact lens adaptation for neophytes with modern contact lens materials.

Evaluating a new objective grading software for conjunctival hyperaemia.

BACKGROUND/ AIMS: Standardised numeric grading scales are used in ophthalmic practice to improve consistency between clinicians in recording the severity of ocular conditions and to facilitate the monitoring of such changes. We investigated the intra- and inter-observer grading reliability and the agreement between subjective Cornea and Contact Lens Research Unit (CCLRU) and Efron grading scales as well as a new Advanced Ophthalmic Systems (AOS) software which uses an objective approach to grading conjunctival hyperaemia. METHODS: One experienced observer graded n = 30 bulbar and n = 26 palpebral conjunctival hyperaemia images to 0.1 increments. Masked grading of randomised images was undertaken for all three methods, on two separate occasions. The agreement within and between the grading methods was assessed between sessions, and compared to the results of a novice observer. RESULTS: There were no statistically significant differences (P > 0.05) between test and retest values. However, repeatability in the grading estimates of both bulbar and palpebral conjunctival hyperaemia was improved using the AOS grading method (R2 = 0.998; Coefficient of Repeatability CoR 0.10-0.13), compared to Efron (R2 = 0.926; CoR 0.62) and CCLRU (R2 = 0.885-0.911; CoR 0.50-0.78). Intraclass coefficient correlations (ICC) improved inter-observer agreement using objective (> 0.995) versus subjective methods (0.853-0.959). CONCLUSION: These subjective and objective grading methods are not interchangeable. Due to the excellent repeatability and improved agreement between experienced and novice observers, the objective grading method provides a more consistent approach when grading ocular abnormalities and may achieve greater reliability in record keeping and clinical monitoring in the future.

Smartphone ophthalmoscopy: patient and student practitioner perceptions.

It can take several years to become proficient at direct ophthalmoscopy; the instrument's single eyepiece allows only one individual to view the image at a time, which is considered disadvantageous during teaching. The introduction of smartphone ophthalmoscopes enables groups of teachers and students to view images together which could encourage peer-to-peer learning. In addition, the technology is significantly cheaper than the direct ophthalmoscope. User acceptability and engagement is essential to the success of any (medical) technological innovation. We sought to understand student opinions of a new commercially-available smartphone device for fundus examination, and compare usability to the traditional ophthalmoscope, from the perspective of both student practitioners and patients. Fifty-four undergraduate optometry students with prior experience of the traditional direct ophthalmoscope were asked to examine at least one eye with the D-EYE smartphone ophthalmoscope and also given an opportunity to experience the D-EYE from a patient's perspective. Minimal instructions were provided and all examinations conducted through undilated pupils. Participants completed an opinion survey to feedback on aspects such as the ease of handling and working distance. Compared to the direct ophthalmoscope, 92% of students preferred the (longer) working distance of the D-EYE; 77% felt it was easier to handle; and 92% preferred the patient experience with the D-EYE. Despite the positive feedback, only 43% of students preferred the D-EYE when assuming the role of the practitioner. Free text responses indicated that students felt the D-EYE may be most useful as a teaching tool. Student opinions indicated that smartphone ophthalmoscopes are an effective training tool for students as an accompaniment to learning the traditional ophthalmoscope method.

The Effects of Severe Myopia on the Properties of Sampling Units in Peripheral Retina.

SIGNIFICANCE: Poor peripheral visual acuity in myopia may reflect, in part, photoreceptor misalignment with the exit pupil of the eye. We speculate that if such misalignment causes sufficient visual deprivation and/or disrupts retinal feedback processes, it may influence eye growth itself. PURPOSE: It is known that myopic eyes have a reduced peripheral resolution acuity relative to emmetropic eyes, though it remains unclear how mechanical stretching of the retina in myopia impacts on peripheral visual performance. Our aim was to determine how retinal stretching affects the properties of sampling units in peripheral vision. METHODS: Three-dimensional magnetic resonance imaging provided a depiction in vivo of ocular shape, allowing the inter-eye ratio of retinal image surface areas and the relative alignment of surfaces to be determined in our observer, who was unique in having severe myopia in the right eye (~21 D) but only modest myopia in the left (~3 D). Visual performance was assessed for the detection and direction discrimination of drifting sinusoids positioned 40° in the temporal retina. Applying the sampling theorem to our measures, we estimated the density and cut-off frequency of the underlying sampling units. RESULTS: The retinal image surface area of the right eye was 40% larger than that of the left and was rotated 8.9° anticlockwise relative to the left eye's image surface. In agreement with a linear stretch model of myopia, the sampling density of the right eye was reduced by approximately the same ratio as that predicted from the inter-eye MRI data, namely, 1.18. However, the cut-off frequency (cycles/mm) of the right eye was approximately half that of the left, a reduction that cannot be explained solely by a linear areal expansion of retinal sampling units. CONCLUSIONS: Poor peripheral acuity in severe myopia may be caused, at least in part, by receptoral misalignment with the exit pupil.

Determination of retinal surface area.

Previous attempts at determining retinal surface area and surface area of the whole eye have been based upon mathematical calculations derived from retinal photographs, schematic eyes and retinal biopsies of donor eyes. 3-dimensional (3-D) ocular magnetic resonance imaging (MRI) allows a more direct measurement, it can be used to image the eye in vivo, and there is no risk of tissue shrinkage. The primary purpose of this study is to compare, using T2-weighted 3D MRI, retinal surface areas for superior-temporal (ST), inferior-temporal (IT), superior-nasal (SN) and inferior-nasal (IN) retinal quadrants. An ancillary aim is to examine whether inter-quadrant variations in area are concordant with reported inter-quadrant patterns of susceptibility to retinal breaks associated with posterior vitreous detachment (PVD). Seventy-three adult participants presenting without retinal pathology (mean age 26.25 ± 6.06 years) were scanned using a Siemens 3-Tesla MRI scanner to provide T2-weighted MR images that demarcate fluid-filled internal structures for the whole eye and provide high-contrast delineation of the vitreous-retina interface. Integrated MRI software generated total internal ocular surface area (TSA). The second nodal point was used to demarcate the origin of the peripheral retina in order to calculate total retinal surface area (RSA) and quadrant retinal surface areas (QRSA) for ST, IT, SN, and IN quadrants. Mean spherical error (MSE) was -2.50 ± 4.03D and mean axial length (AL) 24.51 ± 1.57 mm. Mean TSA and RSA for the RE were 2058 ± 189 and 1363 ± 160 mm2 , respectively. Repeated measures anova for QRSA data indicated a significant difference within-quadrants (P < 0.01) which, contrasted with ST (365 ± 43 mm2 ), was significant for IT (340 ± 40 mm2 P < 0.01), SN (337 ± 40 mm2 P < 0.01) and IN (321 ± 39 mm2 P < 0.01) quadrants. For all quadrants, QRSA was significantly correlated with AL (P < 0.01) and exhibited equivalent increases in retinal area/mm increase in AL. Although the differences between QRSAs are relatively small, there was evidence of concordance with reported inter-quadrant patterns of susceptibility to retinal breaks associated with PVD. The data allow AL to be converted to QRSAs, which will assist further work on inter-quadrant structural variation.