Central and peripheral corneal sagittal height in keratoconus and healthy eyes.

PURPOSE: To determine central and peripheral corneal sagittal height (z) values in keratoconus and healthy eyes with the Oculus Pentacam point-by-point data extraction software. METHODS: Forty eyes from patients with central or paracentral (4 mm) keratoconus (32.0 ± 12.5 years) and 40 eyes from healthy subjects (29.1 ± 7.9 years) were included. The Oculus Pentacam software was employed to determine z values referenced to a plane tangent to the corneal apex for five circles concentric with the centre of the pupil with diameters 4, 6, 8, 9 and 10.5 mm. The variability in z values within each circle and in terms of corneal meridians and quadrants was explored in keratoconus and healthy eyes. RESULTS: Keratoconus apex was mainly located at the inferior-temporal quadrant, at a distance from 0.083 mm to 3.59 mm with reference to the centre of the pupil. Mean z was larger in keratoconus than in healthy eyes in all explored corneal diameters (all p < 0.001). Variation in z values was larger in keratoconus than healthy eyes only at the central areas of the cornea (4 mm, p = 0.02; 6 mm, p = 0.011), but not in the periphery (8, 9 and 10.5 mm). In keratoconus, the frequency of minimum z values in the IT quadrant was greater than in healthy eyes. CONCLUSION: Although peripheral z values were larger in keratoconus, rotational variations were comparable between keratoconus and healthy eyes, suggesting that large diameter spherical rigid corneal contact lenses may be an alternative to scleral lenses in central and paracentral keratoconus.

New Designs of Spectacle Lenses for the Control of Myopia Progression: A Scoping Review.

Myopia control with new designs of spectacle lenses is a flourishing area of research. The present work reviews the effectiveness of new designs (DIMSs, defocus-incorporated multiple segments; CARE, cylindrical annular refractive element; HALs/SALs, highly/slightly aspherical lenslets; DOT, diffusion optics technology) aiming at slowing myopia progression. A search through the PubMed database was conducted for articles published between 1 January 2003 and 28 February 2023. Publications were included if they documented baseline central refraction (SER) and/or axial length (AL) data, and the change in these parameters, in myopic children wearing new designs of spectacle lenses (treatment group) compared to myopic children using single-vision lenses, SVLs (control group). The selection process revealed nine suitable articles. Comparing the mean and standard error values of the treatment and control groups, the highest differences in the change in the SER and AL were -0.80 (1.23) D [95% CI: -1.053 to -0.547; p < 0.001] and 0.35 (0.05) mm [95% CI: 0.252 to 0.448; p < 0.001], respectively; the effect of treatment provided by a HAL design, compared to SVLs, led to a deceleration of 54.8% in the SER and 50.7% in the AL. However, the heterogeneity of the results prevents reaching strong conclusions about the effectiveness of these new designs.

Gender distribution in publishing in five leading optometry journals.

PURPOSE: To explore gender distribution in authorship and citation parameters of articles published in five optometry journals included in the Ophthalmology category of Journal Citation Reports. METHODS: The Scopus database was used to retrieve all citable articles published in 2011 and 2021 in Optometry and Vision Science, Ophthalmic and Physiological Optics, Clinical Experimental Optometry, Contact Lens and Anterior Eye, and Eye and Contact Lens. Gender of the first, last and single authors of all articles, and citation parameters of articles published in 2011 up to May 2023 were determined. Gender of the editor-in-chief and members of the editorial board of these journals was investigated (May 2023). RESULTS: Only one journal had a female editor-in-chief and three journals had more males than females in their editorial board. In 2011 and 2021, respectively, 40.1% and 48.0% of articles had female as the first authors ( χ 1 , 948 2 = 5.77; p = 0.02), and 32.7% and 39.6% had female as the last authors ( χ 1 , 948 2 = 4.61; p = 0.03). Gender parity was observed in one journal for the first author and none for the last author in 2011, and in three journals for the first author and one for the last author in 2021. Regarding combinations of male (M) and female (F) first and last authorship positions, the authors of articles in 2011 were MM (44.5%), FM (22.8%), FF (17.3%) and MF (15.4%), and MM (34.6%), FM (25.8%), FF (22.1%) and MF (17.5%) in 2021. Differences between 2011 and 2021 were statistically significant ( χ 3 , 948 2 = 9.80; p = 0.02). The proportion of authorship combinations did not show statistically significant differences among journals in 2011 or in 2021. Neither citation nor self-citation were influenced by gender. CONCLUSIONS: Gender disparities persist in optometry journals, with females being under-represented in senior and leadership positions. Increasing the awareness of gender disparity in authorship is a necessary step towards ensuring fairness in science in general, and optometry in particular.

Accuracy of a Large Language Model as a new tool for optometry education.

CLINICAL RELEVANCE: The unsupervised introduction of certain Artificial Intelligence tools in optometry education may challenge the proper acquisition of accurate clinical knowledge and skills proficiency. BACKGROUND: Large Language Models like ChatGPT (Generative Pretrained Transformer) are increasingly being used by researchers and students for work and academic assignments. The authoritative and conversationally correct language provided by these tools may mask their inherent limitations when presented with specific scientific and clinical queries. METHODS: Three sets of 10 queries related to contact lenses & anterior eye, low vision and binocular vision & vision therapy were presented to ChatGPT, with instructions to provide five relevant references to support each response. Three experts and 53 undergraduate and post-graduate students graded from 0 to 10 the accuracy of the responses, and the references were evaluated for precision and relevance. Students graded from 0 to 10 the potential usefulness of ChatGPT for their academic coursework. RESULTS: Median scores were 7, 8 and 6 (experts) and 8, 9 and 7.5 (students) for the contact lenses & anterior eye, low vision and binocular vision & vision therapy categories, respectively. Responses to more specific queries were awarded lower scores by both experts (ρ = -0.612; P < 0.001) and students (ρ = -0.578; P = 0.001). Of 150 references, 24% were accurate and 19.3% relevant. Students graded the usefulness of ChatGPT with 7.5 (2 to 9), 7 (3 to 9) and 8.5 (3 to 10) for contact lenses & anterior eye, low vision and binocular vision & vision therapy, respectively. CONCLUSION: Careful expert appraisal of the responses and, particularly, of the references provided by ChatGPT is required in research and academic settings. As the use of these tools becomes widespread, it is essential to take proactive steps to address their limitations and ensure their responsible use.

Loss of Blink Regularity and Its Impact on Ocular Surface Exposure.

(1) Background: Changes in blink parameters have been found to influence ocular surface exposure, eliciting symptoms of dry eye and ocular signs. The aim of the study was to highlight the relevance of including blink regularity as a new parameter to fully characterize blinking; (2) Methods: A novel characterization of blink parameters is described, including spontaneous eyeblink rate (SEBR), percentage of incomplete blinks, and blink regularity. A pilot study was designed in which tear film break-up time (TFBUT), blink parameters, and the time percentage of ocular surface exposure were determined in eight subjects (52.0 ± 16.6 years, 4 females) in three experimental conditions (baseline, reading a hard-copy text, and reading from an electronic display). Blink parameters were monitored through asynchronous image analysis of one minute video segments; (3) Results: All blink parameters were influenced by experimental conditions. A trend was observed in which both reading tasks resulted in an increase in ocular surface exposure, mainly related to a combination of reduced SEBR, increased percentage of incomplete blinks, and loss of blink regularity; (4) Conclusions: A complete characterization of blink parameters is relevant to better understand ocular dryness related to surface exposure and to advice patients towards a reeducation of their blinking habits.

The Relationship between Fixation Stability and Retinal Structural Parameters in Children with Anisometropic, Strabismic and Mixed Amblyopia.

(1) Background: Amblyopia is an ocular condition leading to structural and functional changes. The relationship between these changes is complex and remains poorly understood. (2) Methods: Participants included 31 children aged 5 to 9 years with strabismic (n = 9), anisometropic (n = 16) and mixed (n = 6) unilateral amblyopia, and 14 age-matched non-amblyopic children. The 95% and 63% Bivariate Contour Ellipse Area (BCEA), axial length, Foveal Avascular Zone (FAZ) area, center macular thickness and volume were assessed. The relationship between these parameters was explored. (3) Results: Statistically significant differences were found among the four groups in best corrected distance visual acuity (BCVA) (p < 0.001), BCEA 95% (p = 0.002) and BCEA 63% (p = 0.002), but not in the FAZ area, central macular thickness, central macular volume and axial length. Eyes with amblyopia had poorer BCVA and larger fixation instability than controls. Inter-ocular differences were more significant in patients with strabismic amblyopia, particularly in BCVA (p = 0.003), central macular thickness (p < 0.001) and central macular volume (p = 0.002). In amblyopic eyes, BCEA 95% and 63% were correlated with BCVA, but not with the FAZ area. (4) Conclusion: Amblyopia is associated with a reduction in fixation stability and BCVA, although there is a general lack of correlation with structural changes, suggesting a complex interaction between anatomy and function in amblyopia.

Optometry research in Spain: Topics of interest, institutions and investigators

Purpose: To determine the institutions, journals of choice and topics of investigation of the most prolific and highly cited Spanish optometrist researchers.Methods: As a primary search strategy, the Scopus database (Elsevier) was queried with the terms (optometr* OR "contact lens*" OR refracti* OR *ocular) and the affiliation country filter “Spain”. The list of authors returned by the primary search was used in a secondary manual search based on co-authors and institutions. Authors were included in the analysis if they had an h-index > 10, were of Spanish nationality, were affiliated to Spanish institutions, and possessed an optometry degree. Authors were ranked by h-index, number of publications and number of citations. Topics of research interest and target journals were determined by analyzing the 10 most highly cited papers of each author.Results: A total of 32 authors with an h-index > 10 were identified, of whom 14 (43.7%) were female. Only one author had an h-index > 40, and 7 (21.9%) authors had an h-index over 20. The Journal of Cataract and Refractive Surgery was the first journal of choice (19.1% of highest cited papers), followed by Optometry and Vision Science (10.3%). The Universidad Complutense de Madrid hosted the largest percentage of authors (18.7%), followed by the Universitat de València (15.6%). Main topics of research interest were topography (6.5% of papers), cornea (6.2%) and contact lens (5.0%).Conclusion: Optometry in Spain is a fertile field of research, with an increasing number of highly cited authors publishing in high impact journals. (AU)

Quality of life of caregivers of children with visual impairment: A qualitative approach.

BACKGROUND: Receiving a diagnosis of a child with untreatable visual impairment (VI) may have a negative impact on parents and caregivers, and affect their quality of life (QoL). AIMS: To use a qualitative research approach to determine the impact that caregiving a child with a VI has on the QoL of caregivers in Catalonia (Spain). METHODS: An observational study was designed in which nine parents of children with VI (6 mothers) were recruited following an intentional sampling scheme. In-depth interviews were conducted, and a thematic analysis was performed to identify main themes and subthemes. The QoL domains defined in the questionnaire WHOQoL-BREF guided data interpretation. RESULTS: An overarching theme was defined (the weight on one's shoulders), as well as two main themes (obstacles race and emotional impact) and seven subthemes. QoL was negatively affected by a general lack of knowledge and understanding regarding VI in children and its implications for children and caregivers, whereas social support, gaining knowledge, or cognitive reappraisal had a positive effect. CONCLUSIONS: Caregiving for children with VI affects all QoL domains, resulting in persistent psychological distress. Both administrations and health care providers are encouraged to develop strategies to assist caregivers in their demanding roles.

Optometry research in Spain: Topics of interest, institutions and investigators.

PURPOSE: To determine the institutions, journals of choice and topics of investigation of the most prolific and highly cited Spanish optometrist researchers. METHODS: As a primary search strategy, the Scopus database (Elsevier) was queried with the terms (optometr* OR "contact lens*" OR refracti* OR *ocular) and the affiliation country filter "Spain". The list of authors returned by the primary search was used in a secondary manual search based on co-authors and institutions. Authors were included in the analysis if they had an h-index > 10, were of Spanish nationality, were affiliated to Spanish institutions, and possessed an optometry degree. Authors were ranked by h-index, number of publications and number of citations. Topics of research interest and target journals were determined by analyzing the 10 most highly cited papers of each author. RESULTS: A total of 32 authors with an h-index > 10 were identified, of whom 14 (43.7%) were female. Only one author had an h-index > 40, and 7 (21.9%) authors had an h-index over 20. The Journal of Cataract and Refractive Surgery was the first journal of choice (19.1% of highest cited papers), followed by Optometry and Vision Science (10.3%). The Universidad Complutense de Madrid hosted the largest percentage of authors (18.7%), followed by the Universitat de València (15.6%). Main topics of research interest were topography (6.5% of papers), cornea (6.2%) and contact lens (5.0%). CONCLUSION: Optometry in Spain is a fertile field of research, with an increasing number of highly cited authors publishing in high impact journals.

Short- and mid-term changes in CORVIS ST parameters in successful, adult orthokeratology patients.

CLINICAL RELEVANCE: The changes in various biomechanical and tomographic characteristics of the cornea associated with orthokeratology may allow us to identify potential mid- and long-term structural alterations, resulting in a better understanding of the governing mechanisms of this procedure and in its optimisation. BACKGROUND: The study aimed at describing short and mid-term changes in CORVIS ST® parameters and indices in orthokeratology (ortho-k), and their diurnal variations. METHODS: A prospective observational study was designed in which several CORVIS ST® parameters of 75 new adult participants successfully fitted with overnight ortho-k Seefree® (Conóptica - Hecht Contactlinsen) contact lenses were explored. Measurements were conducted in baseline (BL) conditions and in the morning and evening at the one-night (1 NM/1NT), one-week (1WM/1 WT) and 3-month (3 MM/3MT) follow-up visits. RESULTS: Statistically significant differences were found in DARatio_2 mm, IntRad, ARTh, CBI and TBI following overnight ortho-k, when compared with BL values, with most values reaching stability at 1WM or reverting to BL values at 3 MM. The ARTh and CBI parameters showed some of the most significant temporal variations (both p < 0.001), probably reflecting the encountered differences in central corneal thickness between BL and 1WM (p = 0.010) and between BL and 3 MM (p = 0.016). In general, corneal rigidity was higher in the morning at all follow-up visits, and decreased during the day. No statistically significant changes in adjusted intraocular pressure values were found. CONCLUSION: Ortho-k in adults may be considered a safe procedure in terms of short and mid-term changes in CORVIS ST® parameters. The observed alterations in most of the parameters provided by the Corvis ST® probably responded to the well-described changes in corneal pachymetry and tomography, rather than to actual alterations in corneal rigidity.

Are Patients Sufficiently Informed about Contact Lens Wear and Care?

SIGNIFICANCE: Frequent and effective patient-practitioner communication is essential to ensure that instructions regarding contact lens use, care, and maintenance are understood and followed. Given the relevance of good patient compliance, the responsibility of practitioners to provide adequate information may not be neglected. PURPOSE: This study aimed to determine the content and type of information licensed optometrists in Spain provide their patients during the first contact lens fitting and at follow-up visits. METHODS: A self-reported ad hoc survey was distributed to licensed optometrists in Spain to investigate, among other factors, whether practitioners provided information on several aspects of contact lens use and maintenance, how was this information provided, and whether in-office practical demonstrations were conducted at all contact lens appointments. RESULTS: Respondents of 321 surveys had a median of 20 years of contact lens fitting experience and worked on independent practices (67.6%), and national (29.0%) and regional chains (3.4%). Type of practice influenced continuous education habits ( P = .03). Overall, 28.0% of participants did not always instruct patients on the need to rub contact lenses, 34.3% did not always address contact lens replacement, and 6.8% did not always explain storage case hygiene and replacement. At the follow-up visit, only 8.4% of respondents asked their patients to demonstrate their care routines. Information was mostly oral (48.6%) or oral and written (43.0%). Contact lens-related complications were reported more frequently by participants with less continuous education training ( P = .01), by those not always recommending rubbing ( P = .002), and by those not providing written information about storage case hygiene and replacement ( P = .002). CONCLUSIONS: Patient-practitioner communication was good, albeit several areas were identified where information was insufficient or not provided in a correct and timely format. Precise, written information on rubbing and storage case hygiene and replacement may improve compliance and assist in avoiding complications and dropout.

Vergence and Accommodation Cues in Stereo-Localization during the Small-In Large-Out (SILO) Effect.

A typical procedure in vision therapy is the use of Quoits vectograms to train fusional vergence ranges by improving stereo-localization, which is the ability to correctly locate the target stimulus in space. With this procedure, the Small-In Large-Out (SILO) effect is usually reported in patients with normal binocular vision and accommodation. In this study, the influence of vergence and accommodation cues, as determined with the accommodative-convergence over accommodation (AC/A) ratio, to correctly locate the Quoits vectograms in space was investigated. Twenty participants, aged 29.2 ± 2.8 (mean ± standard deviation) years, without amblyopia or strabismus, were recruited. A geometrical formula was obtained to calculate the theoretical distance to the target stimulus for different vergence demands. Theoretical values were compared with measured distances to the perceived stimuli and stereo-localization accuracy was determined. Stereo-localization accuracy was significantly worse at 10∆ Base In vergence demand (p < 0.001). A statistically significant positive correlation was found between AC/A ratio and stereo-localization accuracy (i.e., worse accuracy) at 10Δ Base Out vergence demand (rho = 0.446, p = 0.049). These findings highlight that AC/A ratio may be a secondary cue for stereo-localization when using vectograms in which the SILO effect is manifest. These results assist in the understanding of the physiological basis of vision therapy procedures.

Far and Near Contrast Sensitivity and Quality of Vision with Six Presbyopia Correcting Intraocular Lenses.

The objective of this prospective, randomized, double-masked study was to compare the contrast sensitivity and quality of vision of patients bilaterally implanted with the following six different presbyopia correcting intraocular lenses (IOLs): SV25T0 (n = 19), ATLISA 809M (n = 18), ATLISA TRI 839MP (n = 19), ZKB00 (n = 20), ZLB00 (n = 20) and Symfony ZXR00 (n = 20). For comparison purposes, 36 patients were implanted with a monofocal lens (ZA9003). Contrast sensitivity was assessed binocularly at distance under photopic, mesopic and mesopic plus glare conditions, and at near under photopic conditions. Quality of vision was explored in terms of photic phenomena and spectacle independence. Overall, the monofocal lens offered better contrast sensitivity, under all illumination conditions, and less occurrence and intensity of photic phenomena. Amongst the multifocal IOL (MIOL) designs, the extended depth of focus Symfony ZXR00 provided better contrast sensitivity than the other MIOLs, particularly at intermediate and high spatial frequencies. Up to 40% and 50% of patients implanted with MIOLs reported glare and halos, respectively. The SV25T0 resulted in less occurrence and intensity of halos. The evaluation of photic phenomena and contrast sensitivity under different illumination conditions may reflect real-life, visually challenging situations, and thus provide insightful information to assist ophthalmic surgeons when selecting the best intraocular lens for their patients.

Validation of the Spanish version of the Low Vision Quality of Life Questionnaire

Purpose: To validate the Spanish Low Vision Qualify of Life (SLVQOL) questionnaire, a quality of life instrument specifically designed for patients with visual impairment, and evaluate its psychometric properties.Methods: The study included 170 visually impaired patients and 195 healthy subjects. Participants were administered the SLVQOL, the NEI VFQ-25, and the EQ 5D-5L questionnaires. Reliability, test–retest reproducibility, feasibility, and construct validity of the SLVQOL were assessed. The Generalized Partial Credit Model was used to fit the data and the performance of each item was characterized using category response curves and item information.Results: The reliability of the SLVQOL was 0.981 (95% CI: 0.978–0.985). Test–retest reproducibility was good (ρ=0.864, P<.001). A cut-off point of 105 or 106 was optimal to detect visual impairment, with a sensitivity of 95.4% and a specificity of 91.8%. Construct validity was shown by the corresponding convergence or divergence correlations between the score of the SLVQOL and its dimensions and the overall and partial scores of the NEI VFQ-25 and the EQ 5D-5L. Item response theory analysis showed discrimination and information parameters ranging from 0.539 to 3.063 and from −1.894 to 1.074, respectively.Conclusion:The SLVQOL was able to quantitatively assess and identify differences in the quality of life among patients with visual impairment and normal subjects. The evaluated psychometric properties suggest that this tool has excellent validity, internal consistency, and reproducibility, but may benefit from a reduction of the number of items. (AU)

Compliance versus Risk Awareness with Contact Lens Storage Case Hygiene and Replacement.

SIGNIFICANCE: Compliance with hygiene and replacement of contact lens (CL) storage cases is key to avoid CL contamination and anterior ocular surface complications. However, compliance levels with these accessories remain low, even in patients with awareness of the risk associated with noncompliance. PURPOSE: This study aimed to determine level of compliance with common practices regarding CL storage case hygiene and replacement, type of information provided by practitioners, and risk perception. METHODS: An ad hoc self-reported survey was used to collect demographic and CL wear details, compliance with storage case care, type of received information, and risk perception (in a 1-to-5 scale). Inferential statistics explored the relationship of demographic details and type of received information with compliance and risk perception. RESULTS: Nondaily disposable wearing participants returned 299 completed surveys, with a median age of 24 years (76.9% females). Monthly replacement silicone hydrogel CLs and multipurpose solutions were predominant. Self-reported compliance with storage case care was poor, with 19.1% of respondents never cleaning their cases, 68.6% exposing them to tap water, and 26.4% failing to replace them within 6 months of acquisition. Two-thirds of respondents received specific information on case maintenance, mainly in oral form. Perceived risk associated with poor-compliance practices was high (median values of 4 and 5), and increased with educational level (P = .02, regarding handwashing; P = .03, regarding case hygiene), with years of CL wear experience (P < .001, regarding handwashing), in those patients provided with specific information on CL case care (P = .01, regarding case replacement). CONCLUSIONS: Compliance with CL storage case hygiene and replacement was generally poor, although awareness of risk associated with noncompliance was high and influenced by factors related to demographic details, CL experience, and patient-practitioner communication. Strategies must be explored to increase risk awareness through education because this may lead to better compliance practices.

Efficacy, predictability and safety of long-term orthokeratology: An 18-year follow-up study.

PURPOSE: To determine the efficacy, predictability and safety of long-term orthokeratology in children and adults. METHODS: Case histories of 300 orthokeratology patients (596 eyes; 34.3% children; 65.7% adults) were reviewed to collect information on demographics, corneal and refractive parameters, visual acuity, residual refraction and adverse effects. Predictability was defined as the percentage of eyes with absolute values of spherical equivalent refraction ≤ 0.5 D of emmetropia, and efficacy as the ratio of post-orthokeratology uncorrected and pre-orthokeratology corrected distance visual acuity. RESULTS: Median duration of treatment was 37 and 28.5 months in children and adults, respectively (p = 0.022). During the first year, 17.2% of children and 33% of adults ceased lens wear (p < 0.001). For children and adults with a successful ortho-k treatment of at least one year of duration, 88.7% and 95.9% of eyes had a predictable refractive outcome, and efficacy was 0.98 and 1.01, respectively. A larger percentage of children (65.7%) were free of complications than of adults (55.4%) (p = 0.015). One event of microbial keratitis occurred in adults (6.8 cases per 10,000 patient-years) and none in children. Corneal staining was the most frequent complication, with a higher incidence in adults (p = 0.007) and in higher myopia (p < 0.001), higher anterior corneal eccentricity (p = 0.019) and smaller anterior horizontal radius (p = 0.027). CONCLUSION: Orthokeratology is a safe and predictable long-term procedure in children and adults, with a low incidence of serious adverse effects. Corneal staining episodes are relatively frequent throughout the course of the treatment, thus highlighting the relevance of education of experienced users.

Validation of the Spanish version of the Low Vision Quality of Life Questionnaire.

PURPOSE: To validate the Spanish Low Vision Qualify of Life (SLVQOL) questionnaire, a quality of life instrument specifically designed for patients with visual impairment, and evaluate its psychometric properties. METHODS: The study included 170 visually impaired patients and 195 healthy subjects. Participants were administered the SLVQOL, the NEI VFQ-25, and the EQ 5D-5L questionnaires. Reliability, test-retest reproducibility, feasibility, and construct validity of the SLVQOL were assessed. The Generalized Partial Credit Model was used to fit the data and the performance of each item was characterized using category response curves and item information. RESULTS: The reliability of the SLVQOL was 0.981 (95% CI: 0.978-0.985). Test-retest reproducibility was good (ρ=0.864, P<.001). A cut-off point of 105 or 106 was optimal to detect visual impairment, with a sensitivity of 95.4% and a specificity of 91.8%. Construct validity was shown by the corresponding convergence or divergence correlations between the score of the SLVQOL and its dimensions and the overall and partial scores of the NEI VFQ-25 and the EQ 5D-5L. Item response theory analysis showed discrimination and information parameters ranging from 0.539 to 3.063 and from -1.894 to 1.074, respectively. CONCLUSION: The SLVQOL was able to quantitatively assess and identify differences in the quality of life among patients with visual impairment and normal subjects. The evaluated psychometric properties suggest that this tool has excellent validity, internal consistency, and reproducibility, but may benefit from a reduction of the number of items.

Public knowledge of low vision and blindness, and readability of on-topic online information

Purpose: To explore the laymen knowledge of low vision and blindness concepts, and to assess the readability of some on-topic information available online. Methods: A cross-sectional study was performed in March 2019. Knowledge was evaluated by means of an ad hoc questionnaire-survey with two dichotomous questions about concepts related to low vision and blindness, followed with a list of 10 true-or-false statements. Readability of two on-topic online texts of different complexity was evaluated asking participants to rate the difficulty they experienced on a Likert scale and, objectively, by means of the freeware INFLESZ Readability Scale for Spanish language. Data analysis included descriptive statistics, t-tests, and ANOVA test (statistical significance: p < 0.05).Results: Fifty-two percent of 103 participants declared never having heard of low vision. Ninety-four percent participants were aware about the word blindness, although most of them misinterpreted it. Neither academic level nor age influenced knowledge (p > 0,05). Higher academic level was related to better readability scores of the complex online text (p < 0.05). Conclusion: Overall, the general public has a limited awareness of low vision and a large misconception of blindness. Therefore, visual health education actions should aim at fostering knowledge and literacy on the issue. This strategy may encourage individuals to seek the advice of eye care providers in order to prevent and treat visual impairment, with relevant consequences in time, both in terms of quality of life and costs. (AU)

Patient - practitioner communication and contact lens compliance during a prolonged COVID-19 lockdown.

PURPOSE: Ocular manifestations and ocular transmission of SARS-CoV-2 in contact lens (CL) wearers may be fostered by non-compliance with care and maintenance instructions which, in turn, may be aggravated by inadequate patient-practitioner communication. The purpose of this research was to determine CL use, compliance and patient-practitioner communication during a 3-month long COVID-19 lockdown in Spain. METHODS: An online survey (developed using Google Forms) retrospectively evaluated CL compliance during the 3-month lockdown (responses captured between 15th July and 10th August, 2020), with particular emphasis on patient-practitioner communication, handwashing practices and CL case hygiene and replacement. RESULTS: A total of 247 responses were collected and analysed. Most participants used monthly replacement soft lenses (64.8 %) and multipurpose solutions (75.7 %), with 86.6 % of them owning a storage case for their lenses. During lockdown, a significant percentage of participants ceased lens wear (28.4 %) or reduced wearing time (49.2 %). Regarding patient-practitioner communication, 54.3 % of respondents received specific instructions, mostly about handwashing (93.3 %) and storage case hygiene (48.5 %). The most frequent non-compliant practices were inadequate handwashing (36.4 %), and overextending monthly or two-weekly replacement lenses (35.2 %). Many respondents never cleaned (23.0 %) nor replaced (16.3 %) their storage case, and 27.8 % of them reported not having been informed about case hygiene by their practitioners. CONCLUSION: Contact lens compliance, particularly in terms of handwashing and storage case hygiene, was poor during a prolonged COVID-19 lockdown, thus stressing the need to foster patient-practitioner communication strategies to curtail the possibility of ocular transmission and the risk of virus tropism.

Should Overnight Orthokeratology Patients Wear Their Lenses During Their Afternoon Nap?

PURPOSE: The purpose of this study was to evaluate changes in visual acuity, corneal curvature, elevation, pachymetry, and objective quality of vision of experienced orthokeratology patients using their contact lenses during a simulated 30-min afternoon nap. METHOD: Twelve patients aged 30.8±8.3 years were recruited for the study, with a history of overnight orthokeratology of 27.4±23.0 months. Patients were instructed to close their eyes for 30 min while wearing their contact lenses or without lenses. Anterior corneal curvature, elevation, and corneal pachymetry were assessed with the Pentacam Scheimpflug System at 17 predefined corneal locations, and the HD Analyzer (Terrassa, Spain) was used to measure objective quality of vision. Measurements were conducted before eye closure (baseline), immediately after eye opening/lens removal (M1), and 30 min later (M2). RESULTS: No statistically significant differences were found in anterior corneal curvature and elevation between baseline values and M1 or M2, with and without contact lenses. Corneal swelling at M1 was greater without contact lenses (change in central corneal thickness of 2.3%±3.1%, P=0.001) than with contact lenses (1.7%±1.3%, P<0.001). Recovery at M2 was slower when lenses were worn. A statistically significant improvement in objective quality of vision and visual acuity was found only when patients napped with their lenses. CONCLUSIONS: Even if no significant changes were found in corneal curvature and elevation, patients of overnight orthokeratology may benefit from using their contact lenses during their afternoon nap in terms of objective quality of vision and visual acuity.