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Vitreomacular traction (VMT) is a condition characterized by an incomplete posterior vitreous detachment resulting in traction on the macula and decreased visual acuity. The process of vitreomacular traction can lead to a number of maculopathies including cystoid macular edema, epiretinal membranes, and macular holes. VMT is more common in patients over 40 years of age; however no population-based studies documenting the prevalence of VMT in this age group has been published. Purpose: The current study was undertaken to evaluate the prevalence of vitreomacular traction syndrome in the population aged above 40. Clinical examination does not adequately illustrate the extent of vitreomacular adhesion; therefore, Optical Coherence Tomography (OCT) was used to determine the presence of VMT. High-definition OCT has provided new insight into vitreomacular traction syndrome by allowing for better visualization of the tractional forces at the vitreoretinal interface. This investigation will analyze the vitreomacular interface with regard to VMT in correlation to age through use of the Spectral Domain OCT. Methods: One hundred and thirty-one eyes of 67 patients (36 females/31 males) were examined by optical coherence tomography (OCT). OCT was performed to obtain high-resolution cross-sectional images of the vitreoretinal interface in the posterior fundus. Results: The status of the posterior vitreoretinal interface was evaluated as follows; (1) Intact Vitreous- No posterior vitreous abnormality is depicted on OCT. (2) Vitreomacular adhesion/incomplete PVD- the posterior vitreous is partially attached and can be seen in contact with the macula on OCT. (3) Vitreomacular traction- the posterior vitreous is partially adhered to the inner retina resulting in distortion of the retinal architecture. (4) Complete posterior vitreous detachment, indicating no contact between the vitreous and retina. Conclusion: OCT results found no vitreous abnormality in 39.7% of all eyes; PVD in 6.87% of eyes, VMA in 51.1% of eyes, and VMT in 2.29% of eyes. Age was a significant risk factor to the development of VMT, while gender was not. As age increases, the probability of having VMT increases by 1.2%. Due to the association between vitreomacular traction and a variety of maculopathies, recognition and diagnosis of this entity is crucial. High definition OCT has allowed for outstanding visualization of the vitreomacular interface, which has allowed for a better understanding of this entity.

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

Thesis (MPH.) -- University of Limpopo, 2017 / Background: Since the introduction of optometry services in 1994 in Limpopo hospitals there is a need to improve the eye care services. Hospital records revealed that most of the spectacles worn by health professionals were not issued by the hospital optometry department. Those who were issued with spectacles when they were newly employed had not renewed from the hospital’s optometry department after the recommended two years. The aim of this study was to determine perceptions and attitudes of public healthcare workers towards optometry services in Zebediela. Limpopo Province, South Africa Methods: A quantitative descriptive cross-sectional study design was used. Participants were public healthcare professionals in Zebediela hospital and clinics in Zebediela sub-local municipality. Following the ethical approval and informed consent, a self-administered questionnaire with closed-ended questions was used to collect information on the perceptions, attitudes and socio-demographic factors. Data were analysed using IBM SPSS statistic 23 software. Results: The majority of participants had negative perceptions (78.7%) and 76.4% had positive attitudes towards the optometry department. There was significant association between perception according to profession of participants (P=0.025). There was significant association between attitude according to profession (P=0.001), as well as years in institutional employment (P=0.035). There was no significant association between either perceptions or attitudes and age group, gender as well as employment experience Conclusion: The health professionals held negative perceptions but favourable attitudes towards the optometry staff and the optometry service but needed more information for themselves and the general patient. The health professionals were not impressed by the type of spectacles issued and optometry service delivery aspects. Awareness campaigns by optometrists, need to be increased to the public and also inter professional relationships need to be strengthened to reduce negative perceptions through peer cross professional education in the health system.

Bien que les examens optométriques soient essentiels pour éviter et traiter les pertes de vision, l’accès aux soins oculovisuels de première ligne au Canada est inéquitable. La technologie permet maintenant aux optommétristes d’effectuer des examens de la vue via la télé-optométrie, mais la littérature scientifique actuelle est insuffisante pour affirmer que les examens télé-optométriques sont équivalents aux examens traditionnels présentiels. Ce mémoire portant sur la télé-optométrie s’inscrit dans une démarche de pratique fondée sur les données probantes et vise à informer les optométristes et les organismes décisionnels sur la qualité des examens généraux télé- optométriques. Une étude comparant les examens de la vue à distance avec ceux effectués en présentiel a d’abord confirmé que la télé-réfraction est statistiquement équivalente à la réfraction subjective présentielle et que l’évaluation de la santé oculaire à distance permet d’identifier la plupart des anomalies oculaires retrouvées dans l’échantillon de l’étude, permettant ainsi d’obtenir des diagnostics similaires entre les deux modalités d’examen. Les résultats de cette première étude ainsi que l’expérience acquise lors de sa réalisation ont permis la publication d’une procédure d’examen de la vue à distance visant à standardiser la télé-pratique afin d’assurer que la qualité des examens à distance au Canada se rapproche le plus possible de celle des examens présentiels. Bien que davantage d’études soient nécessaires pour valider que les examens télé-optométriques sont cliniquement équivalents aux examens présentiels, les résultats de ce mémoire suggèrent que des examens télé-optométriques pourraient être une alternative intéressante lorsque l’accès aux soins oculovisuels en personne n’est pas possible. / Although eye exams are essential to prevent and treat vision loss, access to primary eye care in Canada is inequitable. Technology now makes it easier to access eye exams via tele-optometry. However, the current scientific literature is insufficient to affirm that comprehensive tele- optometric exams are equivalent to traditional in-person eye exams. This master’s thesis on tele- optometry is part of an evidence-based practice approach and aims to inform optometrists and decision-making bodies about the quality of comprehensive tele-optometric exams. A study comparing remote eye exams with those performed in-person first confirmed that tele- refraction is statistically equivalent to in-person subjective refraction and that remote ocular health assessment can identify most of the ocular abnormalities found in the study sample, thus making it possible to obtain similar diagnoses between the two exam modalities. The results of this first study as well as the experience acquired during its realization allowed for the publication of a clinical framework for comprehensive tele-optometric exams aiming at standardizing tele-practice to ensure that the quality of remote eye exams in Canada is as close as possible to that of in-person eye exams. Although more studies are needed to confirm that tele-optometric exams are clinically equivalent to in-person examinations, the results of this master’s thesis suggest that tele-optometric examinations could be an interesting alternative when access to in-person eye care is not possible.

<p><strong>Syfte: </strong>Syftet var att ta reda på vilken metod som är lämpligast att använda för synfältsundersökning vid ett körkortstest hos optiker samt vilken metod det är vanligast att optiker i Sverige använder idag. Dessutom var syftet att utreda varför optiker inte får använda konfrontationstest då det är den metod läkare ska använda för synfältsundersökning enligt körkortsföreskrifterna.</p><p><strong>Metod: </strong>En enkätundersökning med 275 deltagande optiker gjordes. De fick besvara ett fåtal frågor kring vilken metod de använder när de undersöker synfältet vid ett körkortstest samt deras kunskap och inställning till bestämmelserna kring vilken metod som skall användas utav optiker och läkare. Enkätundersökningen publicerades med web-enkätprogrammet Easy Survey.</p><p><strong>Resultat: </strong>Enkätundersökningen visade att endast 58,5 % av optiker i Sverige använder sig av den speciellt avsedda apparaturen. 34,9 % av deltagarna svarade att de använde sig av Donders konfrontationstest. Undersökningen visade på att många optiker i Sverige inte vet vilken metod de enligt föreskriften från 2008 ska använda. Dessutom visar resultaten att en klar majoritet av dem inte förstår varför inte optiker får använda samma metod som läkare för synfältsundersökning vid ett körkortstest.</p><p><strong>Slutsats: </strong>Studien visar att en majoritet av optiker i Sverige använder den av myndigheten rekommenderade metoden men att många också använder Donders. Ett konfrontationstest borde vara mer lämpligt att använda för att undersöka synfältet vid en synprövning för körkort hos optiker än en synfältsapparat. Optiker har tillräckligt stor kunskap för att klara av att använda Donders konfrontationstest och när det utförs korrekt verkar det vara mer tillförlitligt än en apparatur så som Campitestet, då det undersöker synfältet mer utförligt.</p>

<b>Purpose:</b> Assess the relationship between tear film drying and sensation between blinks. <b>Methods:</b> MATLAB sampled a slitlamp video camera, a potentiometer and a microphone while subjects kept one eye open for as long as possible. 23 subjects rated the intensity of the ocular sensation while video and voice data were collected simultaneously. The tear drying on the cornea was measured. <b>Results:</b> The sensation was triphasic. Two linear functions described the latter 2 parts of the data (r &#8805; 0. 95). The correlation between TBUT and the elbow in the time-discomfort function was 0. 72. Extent of tear film drying was linearly correlated to time (median correlation = 0. 88). The correlation between the discomfort elbow and image elbow was 0. 93 with single data pair for each subject. Analysis of sensation characteristics showed significant differences between itching and burning for both intensity and time (p = 0. 03 and p = 0. 02 respectively). <b>Conclusions:</b> Simultaneous recording of ocular surface appearance, discomfort intensity and attributes of sensation provide novel information about the development of discomfort during ocular surface drying. The rapid increase in discomfort proceeding blinking has been quantified and the relationship between the time course of drying and discomfort is elucidated.

Purpose: The aim of the study was to delineate differences in saccade characteristics between a population of athletes and non athletes. Aspects specifically investigated were latency, accuracy, peak velocity, and gain adaptation of saccades using both increasing and decreasing paradigms. Methods: A sample of 28 athletes (varsity badminton and squash players) and 18 non athletes (< 3 hour/week in sports) were studied. Eye movements were recorded at 120Hz using a video based eye tracker (ELMAR 2020). Each subject participated in 2 sessions on separate days. Baseline saccade responses to dot stimuli were measured in both sessions (stimulus size: 5-25 deg). The first session involved a gain decreasing paradigm, induced by displacing the stimulus backwards by 3 degrees from the initial target step (12 deg) for 500 trials. In the 2nd session a gain increase was induced by displacing the stimuli by 3 degrees in the forward direction. The latency and accuracy were calculated from the baseline. The asymptotic peak velocity was calculated from the main sequence (amplitude vs. peak velocity). The amplitude gains, calculated from the adaptation phase, were averaged for every 100 saccade responses. The averaged gains were normalized with respect to the baseline, fitted with a 3rd order polynomial, and differentiated to obtain the rate of change. Differences between the groups were compared using a regression analysis. Results: There were no significant differences in latency, accuracy, and asymptotic peak velocity between athletes and non athletes. No significant differences were seen between the two groups in the magnitude of saccadic adaptation, both for decreasing (- 15% in both groups) and increasing (athletes + 7% and non athletes + 5%) paradigms. However, athletes showed a significantly faster rate of adaptation for the gain increasing paradigm (F = 17. 96[3,6]; p = 0. 002). A significant difference was not observed in the rate of adaptation for the gain decreasing adaptation (F = 0. 856[3,6]; p = 0. 512). Conclusions: The study showed that the athletes do not respond better in terms of reaction time or accuracy of saccades. The significant difference in the rate of change of adaptation between the groups shows that online modification of saccades in the positive direction, although not greater in magnitude, occurs quicker in athletes than non athletes.