Corneal topography with an aberrometry-topography system

Purpose To investigate the agreement between the central corneal radii and corneal eccentricity measurements generated by the new Wave Analyzer 700 Medica (WAV) compared to the Keratograph 4 (KER) and to test the repeatability of the instruments. Methods 20 subjects (10 male, mean age 29.1 years, range 21–50 years) were recruited from the students and staff of the Cologne School of Optometry. Central corneal radii for the flat (rc/fl) and steep (rc/st) meridian as well as corneal eccentricity for the nasal (enas), temporal (etemp), inferior (einf) and superior (esup) directions were measured using WAV and KER by one examiner in a randomized order. Results Central radii of the flat (rc/fl) and steep (rc/st) meridian measured with both instruments were statically significantly correlated (r = 0.945 and r = 0.951; p  0.05). Limits of agreement (LoA) indicate a better repeatability for the KER compared to WAV. Conclusions Corneal topography measurements captured with the WAV were strongly correlated with the KER. However, due to the differences in measured corneal radii and eccentricities, the devices cannot be used interchangeably. For corneal topography the KER demonstrated better repeatability

Everyday visual demands of people with low vision:A mixed methods real-life recording study

Research has demonstrated that low vison aids (LVAs) can have a positive impact on the functional sight of those living with sight loss. Step changes in technology are now enabling new wearable LVAs with greater potential than those available previously. For these novel devices to receive increased acceptance and therefore adoption by those with sight loss, visual task demands have to be understood more clearly in order to enable better alignment between device design and user requirements. The aim of this study was to quantify these requirements. Thirty-two participants aged 18 to 87 wore a spectacle-mounted video camera to capture and narrate all everyday situations in which they would use a "perfect" sight aid during 1 week. Captured scenes were analyzed through categorization and computational image analysis. Results showed large variation in activities and lifestyles. Participants reported no available sight aid or coping strategy for 57% of the recorded activities. Reading made up 49% of all recorded tasks, the other half comprising non-textual information. Overall, 75% of captured activities were performed ad hoc (duration of 0-5 minutes), 78% occurred indoors, 58% occurred at home, 48% were lit by natural light, 68% included the object of interest within reach, and 69% required a single focus plane only. Around half of captured objects of interest had a size of 2 degrees visual angle (2.08 logarithm of the minimum angle of resolution [logMAR]) or smaller. This study highlights the need for a sight aid that can make both textual and non-textual scenes accessible while offering flexibility to accommodate individual lifestyles

Blink Test enhances ability to screen for dry eye disease

Aim To evaluate the patient-administered Optrex™ Dry Eye Blink Test against established clinical criteria for the diagnosis of dry eye disease (DED) and to evaluate its benefit in enhancing screening for DED. Methods Eighty-seven participants aged 38 ± 17 years, (44 female) were screened for DED using the Tear Film and Ocular Surface Society Dry Eye Workshop II (TFOS DEWS II) diagnostic criteria. In addition to symptoms screening with the Ocular Surface Disease Index questionnaire (≥13 cut-off score for DED), these criteria required a sign of loss of homeostasis of the tear film in the form of a non-invasive tear breakup time (NIBUT) 8 (Tearlab), or ocular surface staining (>5 fluorescein corneal spots, >9 lissamine green spots or lid wiper staining [≥2 mm length & ≥25% width]) to confirm a diagnosis of DED. The self-administered Blink Test, which requires the participant to observe an image on a computer screen and report the length of time (in seconds) that they can refrain from blinking without discomfort, was repeated three times. Results Using a cut-off time of 10 s, the Blink Test demonstrated sensitivity of 66%, specificity of 88%, and an area under the curve of 0.77 (p < 0.001), in predicting a diagnosis of DED according to the TFOS DEWS II criteria. The correlation between the Blink Test and NIBUT was r = 0.47 (p < 0.001). When combined with the screening questionnaire, the sensitivity and specificity of the Blink Test increased to 71% and 90%, respectively. Conclusion The Blink Test offers health professionals without advanced instrumentation, as well as patients, themselves, a rapid method of identifying possible DED

Design considerations for the ideal low vision aid: insights from de‐brief interviews following a real‐world recording study

Purpose Low Vision Aids (LVAs) can have a transformative impact on people living with sight loss, yet the everyday requirements for developing such devices remain poorly understood and defined. This study systematically explored LVA requirements through a structured de‐brief interview following a real‐world self‐recording study. The purpose of this work was to define the actual needs of those living with sight loss so that low vision services can better address them in future. Methods Thirty‐two visually impaired volunteers with varying levels of previous LVA experience participated in a de‐brief interview centred around a structured questionnaire. The de‐brief followed a one‐week real‐world study during which participants used recoding spectacles to capture and narrate all situations in which they would use a ‘perfect sight aid’. Content and thematic analyses were used to analyse interviews which had the purpose of contextualising these recordings and exploring requirements around psychological, functional and design factors. Results Participants reported that 46% of tasks which they had recorded were most important to them. Of these tasks, 82% were encountered frequently. Few tasks emerged as very important across many participants, the remaining tasks reflecting individual lifestyles or circumstances. Every participant used at least one LVA in their everyday life and 72% identified further coping strategies. Current LVAs identified as consistently poor were distance LVAs, with all other devices receiving mixed or only positive feedback. Around two‐thirds of participants would prefer LVA use on an ad‐hoc / quick access basis rather than over long periods of time, and just over half would prefer to carry it rather than wearing it all day. Lack of consistency in these responses illustrated potentially different user clusters with divergent design needs. Two‐thirds of participants emphasised the desire for a discreet LVA that does not attract attention. However, since half of all participants felt self‐conscious in public or in front of other people when wearing the small recording spectacles, this may not be technically achievable. Conclusions There is a substantial opportunity for new LVAs to address visual needs that traditional devices and coping strategies cannot support. Functional, psychological and design factors require careful consideration for future LVAs to be relevant and widely adopted

Systemic risk factors of dry eye disease subtypes:A New Zealand cross-sectional study

PURPOSE: To evaluate systemic risk factors of dry eye disease, aqueous tear deficiency, and meibomian gland dysfunction. METHODS: Three hundred and seventy-two community residents (222 females, 150 males; mean ± SD age, 39 ± 22 years) were recruited in a cross-sectional study. Past medical history, dry eye symptomology, ocular surface characteristics, and tear film quality were evaluated for each participant within a single clinical session. The diagnosis of dry eye disease, aqueous tear deficiency, and meibomian gland dysfunction were based on the global consensus recommendations of the Tear Film and Ocular Surface Society's Dry Eye Workshop II (TFOS DEWS II) and International Workshop on Meibomian Gland Dysfunction. RESULTS: Overall, 109 (29%) participants fulfilled the TFOS DEWS II criteria for dry eye disease, 42 (11%) had aqueous tear deficiency, and 95 (26%) had meibomian gland dysfunction. Multivariate logistic regression analysis demonstrated that systemic rheumatologic disease and antidepressant medication were independently associated with aqueous tear deficiency (both p < 0.05). Significant risk factors for meibomian gland dysfunction included age, East Asian ethnicity, migraine headaches, thyroid disease, and oral contraceptive therapy (all p ≤ 0.01). CONCLUSIONS: Both etiological subtypes of dry eye disease were associated with a number of systemic risk factors. These findings would support routine systemic inquiry of dry eye disease and associated systemic conditions and medications, in order to facilitate opportunistic screening and timely inter-disciplinary referral where necessary

IMI - Clinical Myopia Control Trials and Instrumentation Report

The evidence-basis based on existing myopia control trials along with the supporting academic literature were reviewed; this informed recommendations on the outcomes suggested from clinical trials aimed at slowing myopia progression to show the effectiveness of treatments and the impact on patients. These outcomes were classified as primary (refractive error and/or axial length), secondary (patient reported outcomes and treatment compliance), and exploratory (peripheral refraction, accommodative changes, ocular alignment, pupil size, outdoor activity/lighting levels, anterior and posterior segment imaging, and tissue biomechanics). The currently available instrumentation, which the literature has shown to best achieve the primary and secondary outcomes, was reviewed and critiqued. Issues relating to study design and patient selection were also identified. These findings and consensus from the International Myopia Institute members led to final recommendations to inform future instrumentation development and to guide clinical trial protocols