Search

A common non-spectacle strategy to correct presbyopia is to provide simultaneous images with multifocal optical designs. Understanding the neuroadaptation mechanisms behind multifocal devices usage would have important clinical implications, such as predicting whether patients will be able to tolerate multifocal optics. The aim of this study was to evaluate the brain correlates during the initial wear of multifocal contact lenses (CLs) using high-density visual evoked potential (VEP) measures. Fifteen presbyopes (mean age 51.8 ± 2.6 years) who had previously not used multifocal CLs were enrolled. VEP measures were achieved while participants looked at arrays of 0.5 logMAR Sloan letters in three different optical conditions arranged with CLs: monofocal condition with the optical power appropriate for the distance viewing; multifocal correction with medium addition; and multifocal correction with low addition. An ANOVA for repeated measures showed that the amplitude of the C1 and N1 components significantly dropped with both multifocal low and medium addition CL conditions compared to monofocal CLs. The P1 and P2 components showed opposite behavior with an increase in amplitudes for multifocal compared to monofocal conditions. VEP data indicated that multifocal presbyopia corrections produce a loss of feedforward activity in the primary visual cortex that is compensated by extra feedback activity in extrastriate areas only, in both early and late visual processing.

One common option to correct presbyopia is providing simultaneous images with multifocal contact lenses (MCLs). However, patient satisfaction with MCLs is not uniform and fully predictable and it might be modulated by neuroadaptation mechanisms. Using another technique to correct presbyopia with CLs called monovision, the visual evoked potential (VEP) evidenced, after a short period of adaptation to monovision, a compensatory activity in anterior cortical areas used to counteract the degraded V1 signal induced by this kind of correction. This compensatory activity was considered cognitive rather than sensorial. The purpose of the present study was to explore, with the use of VEP with a high-density electrode array, whether this kind of compensation in anterior cortical areas of the brain is present in presbyopes corrected with MCLs too. Multifocal presbyopia corrections produced a loss of feedforward activity in the primary visual cortex but no mod-ulation over anterior cortical areas as the one recorded in monovision. This result suggests that the possible nature of neural compensation for MCLs is not cognitive as in monovision.

Introduction: Evidence based practice is now an important part of healthcare education. The aim of this narrative literature review was to determine what evidence exists on the efficacy of commonly used teaching and learning and assessment methods in the realm of contact lens skills education (CLE) in order to provide insights into best practice. A summary of the global regulation and provision of postgraduate learning and continuing professional development in CLE is included. Method: An expert panel of educators was recruited and completed a literature review of current evidence of teaching and learning and assessment methods in healthcare training, with an emphasis on health care, general optometry and CLE. Results: No direct evidence of benefit of teaching and learning and assessment methods in CLE were found. There was evidence for the benefit of some teaching and learning and assessment methods in other disciplines that could be transferable to CLE and could help students meet the intended learning outcomes. There was evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; clinical teaching and learning, flipped classrooms, clinical skills videos and clerkships. For assessment these methods were; essays, case presentations, objective structured clinical examinations, self-assessment and formative assessment. There was no evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; journal clubs and case discussions. Nor was any evidence found for the following assessment methods; multiple-choice questions, oral examinations, objective structured practical examinations, holistic assessment, and summative assessment. Conclusion: Investigation into the efficacy of common teaching and learning and assessment methods in CLE are required and would be beneficial for the entire community of contact

Purpose: To translate and validate an Italian version of the CLDEQ-8 (CLDEQ-8_IT). Methods: The study was carried out in two phases. In the first phase, a cross-cultural adaptation of CLDEQ-8 to Italian was performed by forward and backward translation in sequence. In the second phase, a multi-centre study was conducted for the validation of the questionnaire. Validity CLDEQ-8_IT was evaluated against three gestalt questions: overall opinion of soft contact lenses (CLs), global self-assessments of eye sensitivity and eye dryness. Reliability was evaluated by test–retest assessment in a subgroup of subjects. Finally, the psychometric properties of CLDEQ-8_IT were explored by Rasch analysis. Results: Two hundred and forty soft CL wearers, fluent Italian speakers (73 males and 167 females), between 18 and 70 years of age were enrolled. A significant correlation was found between CLDEQ-8_IT and each of the three Gestalt questions. The cutoff score of 12 points demonstrated the best balance between sensitivity and specificity in differentiating wearers grading their CLs as “Excellent/Very good” from those reporting their overall opinion as “Good/Fair/Poor”. The Intraclass Correlation Coefficient between test and retest was 0.88 (95% CI: 0.81–0.92). Finally, infit and outfit statistics using Rasch analysis for the 8 items were in a good range, however Principal Components Analysis revealed a certain degree of multi-dimensionality of the instrument. Also, item 8 analysis could be computed after merging the last two response categories. Conclusion: The CLDEQ-8_IT showed very good validity and reliability in measuring symptoms of CL wearers, comparable to the original English language version. A cut-off of 12 was confirmed as yielding the best balance between sensitivity and specificity in detecting CL wearers who could benefit from clinical management of their CL-related symptoms. Collapsing of the response options 5 and 6 in the last item of questionnaire could optimise it

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 amou

Aim: To understand the views of contact lens (CL) practitioners across the globe regarding what they perceive as opportunities and threats in CL practice. Methods: A self-administered anonymised questionnaire, constructed in English and translated in six more languages, was distributed through reputed international professional bodies and academic institutions worldwide. The questionnaire included items on demographic characteristics, type of practice, and questions designed to explore practitioners’ perspective on the future of their CL practice over the next five years. Results: A total of 2408 valid responses were analysed. Multifocal CLs for presbyopia, CLs for myopia control, use of daily disposable (DD) CLs for occasional wear, and biocompatible materials to improve comfort were identified as promising areas of opportunities by practitioners (all 8/10). Respondents from North America, and Europe valued DDCLs for occasional wear moderately more favourable (Median: 9/10 for all) as compared to colleagues in Asia (Median: 8/10, p < 0.001), South America (Median: 8/10, p < 0.01), and Africa (Median: 8/10p < 0.01). Multifocal CLs for presbyopia was perceived as a better opportunity by practitioners in North America and Europe (Median: 9/10 for both), as well as in Australasia (Median: 8/10), in comparison to Asia, Africa, and Middle East (for all Median: 6/10, p < 0.001). Practitioners expressed concerns about the availability of CLs and CL prescriptions online without direct professional involvement (both 9/10). Conclusions: Overall, the most appealing opportunities for CL practice growth were identified in occasional use of DD CLs, biocompatible materials to reduce CL discomfort, multifocal CLs for presbyopia correction and management of myopia control with CLs. Lack of regulation in CL sales, especially online, seemed to be a constant threat. The insights from this study can be used to design targeted strategies to enhance CL practice across the glob

Objective:To investigate eye care practitioners' attitudes and perceptions toward potential interventions that can enhance contact lens (CL) practice across the world, and how this is influenced by their practice setting.Methods:A self-administered, anonymized survey was constructed in English and then forward and backward translated into six more languages. The survey was distributed online via social media platforms and mailing lists involving reputed international professional bodies.Results:In total, 2,222 responses from 27 countries with sufficient responses were analyzed (53% females, median age- 37 years). Most of the respondents were optometrists (81.9%) and 47.6% were from stand-alone/independent practices. Median working experience in CL prescribing was 11.0 years (IQR: 18.0, 4-22 years). Over two-third of them declared themselves to be very hopeful (22.9%) or hopeful (45.1%) about the future of their CL practice. Among the potential interventions proposed, continuous update of knowledge and skills and competently managing CL-related complications were rated the most important (median score: 9/10 for each). Practitioners working in national/regional retail chains expressed higher proactivity in recommending CLs (9/10) than those in local chains, hospitals, and universities (for all 8/10, P<0.05). National differences were also identified in eye care practitioner attitudes and perceptions (P<0.05).Conclusions:The study provided important information to delineate a variety of elements characterizing CL practice across the world. These insights can serve as a basis to design strategies at national and international levels.

Objectives:To evaluate the key factors behind successful and unsuccessful wear of contact lenses (CLs) for patients with presbyopia.Method:A multicenter survey was conducted using a questionnaire, in eight CL centers, among two groups of presbyopes: Successful wearers (SWs), who were presbyopic and wearing CLs successfully, and unsuccessful wearers (UWs), who tried unsuccessfully to wear CLs to manage their presbyopia and had stopped wearing CLs.Results:A total of 237 completed questionnaires were returned; 178 from SWs and 59 from UWs. Successful wearers used CLs 5.8±1.5 days a week and additional reading spectacles were never used by half of the SWs. Among SWs, the most important reason to continue wearing CLs was convenience (61%), whereas among UWs, the most important reason to discontinue wearing CLs was poor vision (80%). A logistic regression analysis showed that the absence of astigmatism (P<0.05), a higher subjective satisfaction (P<0.05), a better subjective perceived vision at distance (P<0.01), and a lower subjective loss of visual contrast (P<0.05) were able to predict the success of CL use for presbyopia.Conclusions:This study explores the predictors for determining successful or unsuccessful CL wear in presbyopes. Among ophthalmic, demographic, lifestyle, and subjective variables, the latter seems to be of greater importance in determining the success of CL wear. Therefore, it is necessary that subjective variables are taken into account by the CL practitioner when approaching presbyopic CL fitting in practice.

Active tobacco smoking, passive smoking, and e-cigarette smoking have been associated with different systemic and ocular diseases. The precorneal tear film plays an important role in eye health and its analysis can provide useful information on ocular status. This review investigates the effects of different types of smoking on the precorneal tear film, by analyzing the peer-reviewed literature on this topic. Specifically, tear evaporation rate, stability, volume, ferning, osmolarity, and physical composition (lipids and proteins) of tear film are detailed. Most of the reported works show that cigarette smoking reduces tear film stability and quality by affecting its components. This review highlights that smoking severely affects the tear film, but a single test is not sufficient to determine these effects because smoking can impact different parts of the eye.

Purpose: In Italy, as a result of the COVID-19 pandemic, optical practices were partially closed during the first lockdown. When practices fully reopened there were changes in the way contact lens (CL) clinical practice was conducted. This study investigates the opinions of CL practitioners (CLPs) at the end of lockdown about the changes they implemented. Methods: An online survey was conducted amongst Italian CLPs after the first lockdown had ended. The anonymised questionnaire included details of demographics, clinical practice, implementation of personal protective measures and reasons for continuing or ceasing to undertake new CL fittings or aftercare visits after lockdown. Results: A total of 104 CLPs completed the questionnaire. Practitioners reported an average reduction of new CL fittings (24.8%) and aftercare visits (17.9%) compared to pre-pandemic numbers. Of the protective measures tested, the use of facemasks and an increased frequency of disinfection of instruments and working spaces were implemented more frequently; these measures were correlated with a lower level of reduction in new fittings and aftercare visits (all P < 0.001). ‘The importance of CLs to patients’ and the ‘professional duty to guarantee access to the service’ were the most important reasons for continuing to conduct new CL fittings and aftercare visits, whilst lack of demand and severity of COVID-19 were the main deterrents against conducting CL practice. In addition, the opportunity to reinforce compliance during aftercare visits was given high importance. Conclusion: The COVID-19 pandemic reduced the frequency of new CL fittings and aftercare visits following lockdown. CLPs acknowledged the importance of CLs for patients and their role in providing access to CLs, even during the challenging circumstances of the pandemic

Purpose: To evaluate the accuracy and repeatability of a computer-generated Pelli–Robson test displayed on liquid crystal display (LCD) systems compared to a standard Pelli–Robson chart. Methods: Two different randomized crossover experiments were carried out for two different LCD systems for 32 subjects: 6 females and 10 males (40.5 ± 13.0 years) and 9 females and 7 males (27.8 ± 12.2 years), respectively, in the first and second experiment. Two repeated measurements were taken with the printed Pelli–Robson test and with the LCDs at 1 and 3 m. To test LCD reliability, measurements were repeated after 1 week. Results: In Experiment 1, contrast sensitivity (CS) measured with LCD1 resulted significantly higher than Pelli–Robson both at 1 and at 3 m of about 0.20 log 1/C in both eyes (p < 0.01). Bland–Altman plots showed a proportional bias for LCD1 measures. LCD1 measurements showed reasonable repeatability: ICC was 0.83 and 0.65 at 1 and 3 m, respectively. In Experiment 2, CS measured with LCD2 resulted significantly lower than Pelli–Robson both at 1 and at 3 m of about 0.10 log 1/C in both eyes (p < 0.01). Bland–Altman plots did not show any proportional bias for LCD2 measures. LCD2 measurements showed sufficient repeatability: ICC resulted 0.51 and 0.65 at 1 and 3 m, respectively. Conclusions: Computer-generated versions of Pelli–Robson test, displayed on LCD systems, do not provide accurate results compared to classic Pelli–Robson printed version. Clinicians should consider that Pelli–Robson computer-generated versions could be non-interchangeable to the printed version.

Purpose: To evaluate, in an amateur sports-playing population, the prevalence of refractive error, the type of vision correction used during sport and attitudes toward different kinds of vision correction used in various types of sports. Method: A questionnaire was used for people engaging in sport and data was collected from sport centres, gyms and universities that focused on the motor sciences. Results: One thousand, five hundred and seventy-three questionnaires were collected (mean age 26.5 ± 12.9 years; 63.5 per cent male). Nearly all (93.8 per cent) subjects stated that their vision had been checked at least once. Fifty-three subjects (3.4 per cent) had undergone refractive surgery. Of the remainder who did not have refractive surgery (n = 1,519), 580 (38.2 per cent) reported a defect of vision, 474 (31.2 per cent) were myopic, 63 (4.1 per cent) hyperopic and 241 (15.9 per cent) astigmatic. Logistic regression analysis showed that the best predictors for myopia prevalence were gender (p < 0.001) and location of sport practice (p < 0.001). Sports that present higher prevalence of outdoor activity have lower prevalence of myopia. Contact lens penetration over the study sample was 18.7 per cent. Contact lenses were the favourite system of correction among people interviewed compared to spectacles and refractive surgery (p < 0.001). Conclusions: This study showed that sport was not associated with different levels of myopia prevalence in the adult population. However, subjects engaging in outdoor sports had lower rates of myopia prevalence. Penetration of contact lens use in sport was four times higher than the overall adult population. Contact lenses were the preferred system of correction in sports compared to spectacles or refractive surgery, but this preference was affected by the type of sport practised and by the age and level of sports activity for which the preference was required.

Key points: Monovision is an optical correction for presbyopes that consists of correcting one eye for far distance and the other for near distance, creating a superimposition of an in-focus with a blurred image. Brain adaptation to monovision was studied in unexperienced observers by measuring visual evoked potentials from 64-channels. The first clear effect of monovision on visual evoked potentials was the C1 amplitude reduction, indicating that the unilateral blurring induced by monovision reduces feed-forward activity in primary visual area. Monovision led also to an increased amplitude of the P1 and pP1 components, with the latter originating in prefrontal regions. This effect probably works as an attentional compensatory activity used to compensate for the degraded V1 signal. Abstract: A common and often successful option to correct presbyopia with contact lenses is monovision. This is an unbalanced correction across the two eyes where one eye is corrected for far vision and the other eye is corrected for near vision. Monovision is therefore a form of acquired anisometropia that causes a superimposition of an in-focus image with a blurred image. In spite of this visual anisometropia, monovision has been successfully used for many decadesl however the brain mechanism supporting monovision is not well understood. The present study aimed to measure the visual evoked potentials with a high-density electrode array (64-channel) in a group of presbyopes and to provide a detailed spatiotemporal analysis of the cortical activity after a short period of adaptation to monovision with contact lenses. When compared with a balanced eye near correction, monovision produced both a clear reduction of the earliest visual evoked potential components, the C1 and the N1, and an amplitude increase of the P1 and pP1. These results indicate that the unilateral blurring induced by wearing monovision contact lenses reduces feed-forward activity in the primary visual area and feedback a

Purpose: To evaluate the accuracy and reliability (inter and intra-observer) of a method to assess multifocal contact lenses (MCLs) centration using a corneal topography unit. Method: Daily-disposable MCLs (Fusion 1 day Presbyo) were fitted on both eyes of the subjects. For each lens fit a slit lamp digital picture and videokeratograph image were taken in a rapid but randomised sequence. Photo-editing software was used to assess the position of the MCL centre with respect to pupil centre as taken from the slit lamp photograph. The position of the MCL centre was automatically detected as the point of maximum curvature from the videokeratography. Three further manual and qualitative procedures to detect MCL centre, comparing a template of CLs optic zones to the videokeratographic image were performed by 4 practitioners using 3 different algorithms to represent the topographic map. Each manual reading was repeated 3 times. Results: Twenty-two subjects (11 males) aged 22.8 ± 1.9 years (range 20.8–27.0 years) were recruited. The accuracy of the 4 topographic assessments in determining the centre coordinates of the MCL with respect to SL assessment was good: no differences were found in the left eyes and although in the right eyes a more temporal and superior position of MCLs was determined (paired t-test, p < 0.05) the difference was clinically negligible (0.16 ± 0.36 mm horizontally, 0.23 ± 0.48 vertically). Amongst the 4 practitioners one-way Anova for repeated measures showed no differences for any of the 3 manual assessments. Intra-class correlation coefficient was calculated among the 3 readings for each manual procedure and was very good (between 0.75 and 0.98) in 3 practitioners and moderate (between 0.49 and 0.92) in the fourth. Conclusions: The assessment of MCL centration by performing corneal topography over the MCL is an accurate method. Furthermore, inter and intra-practitioner reliability showed by manual procedures appeared very good.

Monovision can be used as a method to correct presbyopia with contact lenses (CL) but its effect on reading behavior is still poorly understood. In this study eye movements (EM) were recorded in fifteen presbyopic participants, naïve to monovision, whilst they read arrays of words, non-words, and text passages to assess whether monovision affected their reading. Three conditions were compared, using daily disposable CLs: baseline (near correction in both eyes), conventional monovision (distance correction in the dominant eye, near correction in the non-dominant eye), and crossed monovision (the reversal of conventional monovision). Behavioral measures (reading speed and accuracy) and EM parameters (single fixation duration, number of fixations, dwell time per item, percentage of regressions, and percentage of skipped items) were analyzed. When reading passages, no differences in behavioral and EM measures were seen in any comparison of the three conditions. The number of fixations and dwell time significantly increased for both monovision and crossed monovision with respect to baseline only with word and non-word arrays. It appears that monovision did not appreciably alter visual processing when reading meaningful texts but some limited stress of the EM pattern was observed only with arrays of unrelated or meaningless items under monovision, which require the reader to have more in-depth controlled visual processing.