Novelty Optimisation Techniques For Myopia Assessment & Management

This thesis hoped to inform the practice of future individual myopia management. All myopia risk factors across global ethnic regions must be considered, instead of relying on the most widely used averaged parameters, towards the development of growth model tools. There could be possible crucial cut points of near phoria development at specified age ranges, earlier and later in life, suggesting this myopia risk factor should be measured alongside other primary outcome parameters important for treatment efficacy. Other notable human lifespan findings included: emmetropic and female patients attended eye examinations more frequently; females exhibited higher levels of near phoria and myopia; myopes were more esophoric than emmetropes, progressive myopes were more esophoric than both myopes and emmetropes, and were less likely to increase in exophoria with age. The presumed design optimisation, regarding daily CE-marked optical myopia control strategies, was based on the possible mechanism behind myopic retinal defocus (blur) and accommodative lag in myopia development and progression. Contact lens designs could have an inherent characteristic for their treatment effect in the temporal retina at 30° and J0 astigmatic component. Multifocal contact lenses for myopia control significantly impacted glare, but did not affect contrast sensivitiy differently than standard lenses, and would offer equally acceptable treatment compliance and qualifty of life expectations. Specialty instrumentation for measuring primary outcomes (refraction and axial length) should be used interchangeably for myopia control studies. This was confirmed between the gold standard biometers, IOLMaster 700 and IOLMaster 500, for the key parameters of axial length, anterior chamber depth and corneal topography, where discrepancies in white-to-white corneal diameter values, following MiSight and NaturalVue contact lens wear, were minimal and clinically irrelevant. Further novel discoveries proved myopia control contact lenses were viable non-invasive sampling vehicles for human dopamine detection. Thus, the thesis probed the viability of novelty applications of such “labelled” and/or gold standard medical devices and instrumentations towards treating individual myopic patients and highlighted that appropriate global myopia management and standardisation remain poor

How should initial fit inform soft contact lens prescribing

Purpose: To investigate how initial HEMA and silicone-hydrogel (SiHy) contact lens fit on insertion, which informs prescribing decisions, reflect end of day fit. Methods: Thirty participants (aged 22.9. ±. 4.9 years) were fitted contralaterally with HEMA and SiHy contact lenses. Corneal topography and tear break-up time were assessed pre-lens wear. Centration, lag, post-blink movement during up-gaze and push-up recovery speed were recorded after 5,10,20. min and 8. h of contact lens wear by a digital slit-lamp biomicroscope camera, along with reported comfort. Lens fit metrics were analysed using bespoke software. Results: Comfort and centration were similar with the HEMA and SiHy lenses (p > 0.05), but comfort decreased with time (p 0.05), but was slower with SiHy after 8. h wear (p = 0.016). Lens movement on blink and push-up recovery speed was predictive of the movement after 8. h of wear after 10-20. min SiHy wear, but after 5 to 20. min of HEMA lens wear. Conclusions: A HEMA or SiHy contact lens with poor movement on blink/push-up after at least 10. min after insertion should be rejected

Global trends in myopia management attitudes and strategies in clinical practice – 2019 Update

Purpose: A survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later. Methods: A self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies. Results: Of the 1336 respondents, concern was highest (9.0 ± 1.6; p < 0.001) in Asia and lowest (7.6 ± 2.2; p < 0.001) in Australasia. Practitioners from Asia also considered their clinical practice of myopia control to be the most active (7.7 ± 2.3; p < 0.001), the North American practitioners being the least active (6.3 ± 2.9; p < 0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by pharmaceutical approaches and approved myopia control soft contact lenses (p < 0.001). Although significant intra-regional differences existed, overall, most practitioners did not consider single-vision distance under-correction to be an effective strategy for attenuating myopia progression (79.6 %), but prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients (63.6 ± 21.8 %). The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (20.6 %) and inadequate information (17.6 %). Conclusions: While practitioner concern about myopia and the reported level of activity have increased over the last 4 years, the vast majority of eye care clinicians still prescribe single vision interventions to young myopes. With recent global consensus evidence-based guidelines having been published, it is hoped that this will inform the practice of myopia management in future

Human data interactions in digital modes of eye care

In eye care, work on developing algorithms to improve the early detection and diagnosis of diseases is underway. The use of artificial intelligence in clinical decision making has transformed the landscape of Big Data, inevitably changing the scope of practice of ophthalmic providers, while also impacting student learning at the pre-professional level. This data needs to be used in meaningful and ethical ways. These innovations intend to revolutionize medicine through combining ancestry, demographic, environmental, image based and genetic data to enable accurate classification of eye health and disease by accounting for the diversity of the human population, including efforts to develop individualized data driven care. This chapter will review new models that utilize human data interactions and provide specific eye conditions as examples. Further framework advances in which teleophthalmology services are delivered will be presented. The need for monitoring of patient safety, privacy, traceability, accountability, and security, with plans in place to address any breaches will be highlighted. Challenges for validation, clinical implementation, postdigital adaptation, and recommendations on future directions, gaps, and unmet clinical needs will also be discussed, as they relate to eye care

Topical Sustained Delivery of Miltefosine Via Drug-Eluting Contact Lenses to Treat Acanthamoeba Keratitis

This study aimed to develop a miltefosine-eluting contact lens (MLF-CL) device that would allow sustained and localized miltefosine release for the treatment of Acanthamoeba keratitis. MLF-CLs were produced in three different miltefosine doses by solvent-casting a thin miltefosine-polymer film around the periphery of a methafilcon hydrogel, which was then lathed into a contact lens. During seven days of in vitro testing, all three formulations demonstrated sustained release from the lens at theoretically therapeutic levels. Based on the physicochemical characterization of MLF-CLs, MLF-CL’s physical properties are not significantly different from commercial contact lenses in terms of light transmittance, water content and wettability. MLF-CLs possessed a slight reduction in compression modulus that was attributed to the inclusion of polymer-drug films but still remain within the optimal range of soft contact lenses. In cytotoxicity studies, MLF-CL indicated up to 91% viability, which decreased proportionally as miltefosine loading increased. A three-day biocompatibility test on New Zealand White rabbits revealed no impact of MLF-CLs on the corneal tissue. The MLF-CLs provided sustained in vitro release of miltefosine for a week while maintaining comparable physical features to a commercial contact lens. MLF-CL has a promising potential to be used as a successful treatment method for Acanthamoeba keratitis