Purpose: To locate protein sorption on the surface and inside the matrix of soft contact lens materials and intraocular lenses (IOL). Methods: The proteins albumin and lysozyme were investigated as they are highly abundant in blood serum and tears, respectively. Proteins were conjugated with organic fluorescent probes and using confocal laser scanning microscopy (CLSM) the sorption profile to contact lenses and IOL could be determined. Radiolabeled protein was used for quantification purposes. • Albumin sorption to etafilcon A and lotrafilcon B was determined (Chapter 3) • Different fluorescent probes were used for conjugation and the impact on albumin sorption behaviour was investigated (Chapter 4) • Lysozyme sorption to nine different pHEMA-based and silicone hydrogel contact lenses was determined using two fluorescent probes (Chapter 5) • The efficiency of protein removal from contact lenses using contact lens care regimens was investigated (Chapter 6) • Albumin sorption to IOL materials was quantified and imaged using a modified CLSM technique (Chapter 7) Results: Albumin and lysozyme sorption profiles differed between materials, and were influenced by the fluorescent probes used for conjugation. After one day of incubation, both proteins could be located within all contact lens materials, except for lotrafilcon A and lotrafilcon B, which primarily allowed deposition on the lens surface. An increase in protein accumulation was found for most materials over the maximum investigated period of 14 days, using CLSM and radiolabel techniques. The efficiency of contact lens care regimens to remove lysozyme and albumin depended on the lens material, care regimen and protein type investigated. PMMA and silicone IOLs showed protein exclusively on the surface, while a hydrophilic acrylic IOL allowed penetration into the lens matrix over time. Despite the albumin penetration depth into hydrophilic acrylic, the highest albumin levels were determined for the silicone IOL. Conclusions: CLSM provides detailed information that can describe the protein distribution in transparent biomaterials, with scanning depths up to a few hundred microns. However, the CLSM data are primarily of qualitative value, which necessitates a quantitative technique (e.g. radiolabeling) to determine the total protein content.

Purpose: To locate protein sorption on the surface and inside the matrix of soft contact lens materials and intraocular lenses (IOL). Methods: The proteins albumin and lysozyme were investigated as they are highly abundant in blood serum and tears, respectively. Proteins were conjugated with organic fluorescent probes and using confocal laser scanning microscopy (CLSM) the sorption profile to contact lenses and IOL could be determined. Radiolabeled protein was used for quantification purposes. • Albumin sorption to etafilcon A and lotrafilcon B was determined (Chapter 3) • Different fluorescent probes were used for conjugation and the impact on albumin sorption behaviour was investigated (Chapter 4) • Lysozyme sorption to nine different pHEMA-based and silicone hydrogel contact lenses was determined using two fluorescent probes (Chapter 5) • The efficiency of protein removal from contact lenses using contact lens care regimens was investigated (Chapter 6) • Albumin sorption to IOL materials was quantified and imaged using a modified CLSM technique (Chapter 7) Results: Albumin and lysozyme sorption profiles differed between materials, and were influenced by the fluorescent probes used for conjugation. After one day of incubation, both proteins could be located within all contact lens materials, except for lotrafilcon A and lotrafilcon B, which primarily allowed deposition on the lens surface. An increase in protein accumulation was found for most materials over the maximum investigated period of 14 days, using CLSM and radiolabel techniques. The efficiency of contact lens care regimens to remove lysozyme and albumin depended on the lens material, care regimen and protein type investigated. PMMA and silicone IOLs showed protein exclusively on the surface, while a hydrophilic acrylic IOL allowed penetration into the lens matrix over time. Despite the albumin penetration depth into hydrophilic acrylic, the highest albumin levels were determined for the silicone IOL. Conclusions: CLSM provides detailed information that can describe the protein distribution in transparent biomaterials, with scanning depths up to a few hundred microns. However, the CLSM data are primarily of qualitative value, which necessitates a quantitative technique (e.g. radiolabeling) to determine the total protein content.

M. Tech. Pharmaceutical Sciences Tshwane University of Technology 2013. / Aims of the present study was to evaluate the inhibitory activities of essential oils against Fusarium isolates and their corresponding biofilms. In this study, the chemical compositions of the oils were established using gas chromatography with both mass spectrometric and flame ionization detection, for identification and quantification, respectively.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2009. / Title from PDF title page (viewed on Sept 9, 2009). Includes bibliographical references (p. 120-125).

The reduction in visual performance typically found in keratoconic patients is believed to be associated with large magnitudes of uncorrected irregular astigmatism and higher-order aberrations (HOAs). Previous studies indicate that correcting HOAs in keratoconus patients may result in an improvement in visual performance. This thesis explores the correction of HOAs using standard sphero-cylindrical and customised aberration-controlling soft contact lenses in 22 patients with keratoconus. The findings of this work may be useful from a clinical perspective, as some keratoconic patients cannot tolerate rigid gas-permeable (RGP) contact lenses and have few alternatives, excluding surgical intervention, for vision correction. This thesis firstly describes a series of preliminary studies conducted to improve our current understanding of the HOAs manifested in keratoconus. The results of these investigations suggested that alterations in aberrations, due to changes in accommodation or variations in the pre-corneal tear film post-blink, were unlikely to hinder the correction of HOAs for keratoconic patients. Equally, it was ascertained that subjective refraction data provided significantly better visual acuity compared to objective, aberrometry-derived refractions for patients with keratoconus. The findings also show that both lower-order aberrations (LOAs) and HOAs displayed a larger degree of variability in keratoconic eyes compared to those previously reported for visually-normal subjects. Furthermore, significant increases in 3rd-order coma root mean square aberrations were found after temporarily suspending RGP contact lens wear for 16 keratoconic patients. The results of two clinical studies suggested that standard sphero-cylindrical soft lenses can, to some extent, mask HOAs in keratoconic patients; however, the visual performances achieved were found to be poorer compared to RGP lenses. Equally, the results showed that RGP lenses provide superior visual performances compared to customised, aberration-controlling lenses, in spite of the customised lenses providing comparable reductions in uncorrected HOAs. The inducement of superfluous HOAs and LOAs, through customised contact lens translations and rotations, were modelled using MatLab (version 7.6.0.324; The Mathworks, Natick, MA, US). The results confirmed that minimising the decentration of aberration-controlling contact lenses, to less than 5 degrees of rotation and less than 0.50 mm of translation, will help to achieve an optimal correction of HOAs. However, more stringent criteria were required for LOAs, where rotational displacements should be reduced to less than 3 degrees and translational displacements should be limited to less than 0.10 mm. In conclusion, the correction of HOAs for patients with keratoconus is possible using customised, aberration-controlling soft contact lenses; however, several factors will govern their success, including the repeatability and accuracy of HOA measurements for these irregular corneas, and the stability of the customised lenses on-eye.

Photographic fisheye lenses with fixed focal length for cameras with different sensor formats have been well developed for decades. However, photographic fisheye lenses with variable focal length are rare on the market due in part to the greater design difficulty. This paper presents a large aperture zoom fisheye lens for DSLR cameras that produces both circular and diagonal fisheye imaging for 35-mm sensors and diagonal fisheye imaging for APS-C sensors. The history and optical characteristics of fisheye lenses are briefly reviewed. Then, a 9.2- to 16.1-mm F/2.8 to F/3.5 zoom fisheye lens design is presented, including the design approach and aberration control. Image quality and tolerance performance analysis for this lens are also presented. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

Background: Augmented Reality (AR) could be the next revolutionary technology after the personal computer, the internet and the mobile era. While AR Smart Glasses are already on the market, AR Contact Lenses (ARCL) are still in the stage of research and development, but likely to replace the smartphone in the near future. Purpose: The purpose of this thesis is the identification of key factors influencing the acceptance of ARCL from a potential user perspective to gather early-stage pre-market knowledge and extend the Technology Acceptance Model (TAM) literature to this novel wearable technology. Method: An explanatory online survey was conducted to test the hypotheses in an extended TAM. Data from 250 respondents up to an age of 34 years, representing the potential target group was collected. Partial Least Squares Structural Equation Modeling (PLS-SEM) was used to assess the measurement model in terms of validity and reliability and the structural model in terms of hypotheses testing and strength of relationships between proposed variables. In addition, a multigroup analysis was examined to identify significant differences among groups. Conclusion: The results show that the attitude, which is strongly influenced by perceived usefulness, is the major key determinant affecting potential users’ behavioral intention to adopt ARCL in the future, followed by subjective norms. Furthermore, a strong influence of personal innovativeness on both antecedents of attitude, perceived usefulness and perceived ease of use was identified. Moreover, moderating effects of educational background, knowledge of ARCL and usage of contact lenses were discovered.

No description available.

No description available.

Yes / Objectives: To investigate the performance of a novel flat pack toric daily disposable contact lens compared with traditionally packaged toric lenses in a randomized, crossover study. Environmental attitudes to contact lens wear were also explored. Methods: Habitual contact lens wearers were recruited to wear a hioxifilcon A (Miru 1 day Flat Pack Toric, Menicon, Nagoya, Japan) test lens and a control lens: either nelfilcon A (Dailies AquaComfort Plus, Alcon, Geneva, Switzerland) or etafilcon A (1-Day Acuvue Moist, Johnson & Johnson, New Brunswick, NJ). Objective lens performance was assessed at fitting, and participants wore lenses in a randomized order for three consecutive days. Subjective measures of lens performance (comfort, vision, and handling) were then assessed by a questionnaire, with further questions on overall lens preference and environmental perceptions. Results: Objective measures of lens fit were similar for the test and control lenses, except for distance VA which was better with the control lenses (P<0.05; difference of two logMAR letters). End of day comfort was greater with the test lens, but this did not reach significance. Both lenses demonstrated similar scores for overall satisfaction. 87.5% of participants indicated the environmental impact of contact lenses to be important/extremely important to them, with 100% of participants identifying the flat pack packaging as having a smaller environmental impact. Conclusion: Overall, the lenses used in the study performed to similar levels. Environmental credentials are important to contact lens wearers, which may contribute to overall lens preference.