Simulated images can provide insight into the performance of optical systems, especially those with complicated features. Many modern solutions for presbyopia and cataracts feature sophisticated power geometries or diffractive elements. Some intraocular lenses (IOLs) arrive at multifocality through the use of a diffractive surface and multifocal contact lenses have a radially varying power profile. These type of elements induce simultaneous vision as well as affecting vision much differently than a monofocal ophthalmic appliance. With myriad multifocal ophthalmics available on the market it is difficult to compare or assess performance in ways that effect wearers of such appliances. Here we present software and algorithmic metrics that can be used to qualitatively and quantitatively compare ophthalmic element performance, with specific examples of bifocal intraocular lenses (IOLs) and multifocal contact lenses. We anticipate this study, methods, and results to serve as a starting point for more complex models of vision and visual acuity in a setting where modeling is advantageous. Generating simulated images of real- scene scenarios is useful for patients in assessing vision quality with a certain appliance. Visual acuity estimation can serve as an important tool for manufacturing and design of ophthalmic appliances.

A rabbit keratoconjunctivities model was used to evaluate ophthalmic formulations containing 1 percent sodium cephalothin in silicon oil, a 1 percent sodium cephalothin aqueous solution, and a 0.3 percent gentamicin sulfate solution. Rabit eyes were inoculated intracorneally with Pseudomonas aeruginosa, Staphylococcus aureus, or Streptococcus pneumoniae, After topical treatment, none of the antibiotic formulations were effective in the P. aeruginosa model; all three showed good activity against S. aureus, and against S. pneumoniae, the caphalothin formulations were more effective than gentamicin.In a related stability study, the cephalothin potency of the silicon formulation was maintained for 16 weeks at 4, 25, and 450 C These studies suggest that sodium cephalothin can be formulated as an effective and stable ophthalmic dosage form.

Class of 2006 Abstract / Objectives: To evaluate the comparative efficacies of Tacrolimus and Pimecrolimus for the treatment of Keratoconjunctivitis Sicca (KCS), Pannus, and other autoimmune related ophthalmological disorders. Methods: A descriptive retrospective study of clinical data obtained through two separate veterinary studies. The improvement in Schirmer Tear Test (STT) between the Tacrolimus group and Pimecrolimus group is compared. Results: There were 27 canines in the Tacrolimus group, with a total of 50 affected eyes. The Pimecrolimus group had 14 total canines, but tear production was measured in only 8, for a total of 16 affected eyes. At baseline, there was no significant difference in tear production between the two groups. At first and second follow up, and in both eyes, Tacrolimus produced a significantly greater increase in tear production than Pimecrolimus (p=0.0093 and p=0.0292 respectively for the right eye first and second follow up; p=0.0425 and p=0.0065 respectively for the left eye first and second follow up). Conclusions: Treatment with Tacrolimus produced a greater increase in tear production that Pimecrolimus in canines with autoimmune keratitis.

Suspensões oftálmicas de dexametasona e polimixina B foram formuladas variando-se os conservantes e combinando 2 concentrações de polissorbato 20 e hidroxipropilmetilcelulose segundo o projeto fatorial 2n. A estabilidade das preparações foi avaliada através de parâmetros físicos, com ênfase na facilidade de rehomogeneização após período de repouso. Das 16 fórmulas foram selecionadas 8 para avaliação da eficácia antimicrobiana do sistema conservante pelo método de desafio, segundo B.P. 88, frente a Pseudomonas aeruginosa, Pseudomonas cepacia e Sthaphylococcus aureus. O ensaio foi precedido de validação da técnica segundo planejamento estatistico two way e split + plot. Os produtos contendo associação clorhexidina e álcool feniletílico atenderam às exigências do compêndio adotado, em oposição aos sistemas contendo cloreto de benzalcônio e EDTA, além de clorhexidina e EDTA, independente da concentração do tensoativo e agente suspensor. / Ophthalmic suspensions of dexametasone and polymyxin B were formulated varying the preservatives and combining two concentrations of polysorbate 20 and hydroxypropylmethylcellulose according to the factorial project 2n. The stability of the preparations were evaluated through physical parameters, with emphasis on the easing of the rehomogenization after a period of rest. 8 of the 16 formula were selected for an evaluation of the antimicrobial efectiveness of the preservative system through the challenge method, according to B.P. 88, against Pseudomonas aeruginosa, Pseudomonas cepacia and Sthaphylococcus aureus. The test was preceded by a validation of the technique according to statistical planning two way and split + splot. The products containing the association of chorhexidine and phenylethyl alcohol complied to the requirements of the adopted compendium, in opposition to the systems containing benzalkonium chloride and EDTA, besides clorhexidine and EDTA, not depending on the concentration of the surfactant and suspending agents.

Yu, Chak Yan Marco. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 153-178). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Suspensões oftálmicas de dexametasona e polimixina B foram formuladas variando-se os conservantes e combinando 2 concentrações de polissorbato 20 e hidroxipropilmetilcelulose segundo o projeto fatorial 2n. A estabilidade das preparações foi avaliada através de parâmetros físicos, com ênfase na facilidade de rehomogeneização após período de repouso. Das 16 fórmulas foram selecionadas 8 para avaliação da eficácia antimicrobiana do sistema conservante pelo método de desafio, segundo B.P. 88, frente a Pseudomonas aeruginosa, Pseudomonas cepacia e Sthaphylococcus aureus. O ensaio foi precedido de validação da técnica segundo planejamento estatistico two way e split + plot. Os produtos contendo associação clorhexidina e álcool feniletílico atenderam às exigências do compêndio adotado, em oposição aos sistemas contendo cloreto de benzalcônio e EDTA, além de clorhexidina e EDTA, independente da concentração do tensoativo e agente suspensor. / Ophthalmic suspensions of dexametasone and polymyxin B were formulated varying the preservatives and combining two concentrations of polysorbate 20 and hydroxypropylmethylcellulose according to the factorial project 2n. The stability of the preparations were evaluated through physical parameters, with emphasis on the easing of the rehomogenization after a period of rest. 8 of the 16 formula were selected for an evaluation of the antimicrobial efectiveness of the preservative system through the challenge method, according to B.P. 88, against Pseudomonas aeruginosa, Pseudomonas cepacia and Sthaphylococcus aureus. The test was preceded by a validation of the technique according to statistical planning two way and split + splot. The products containing the association of chorhexidine and phenylethyl alcohol complied to the requirements of the adopted compendium, in opposition to the systems containing benzalkonium chloride and EDTA, besides clorhexidine and EDTA, not depending on the concentration of the surfactant and suspending agents.

published_or_final_version / Anatomy / Master / Master of Philosophy

In this study, fluorescein angiograms of the ocular fundus have been digitised to enable them to be processed and analysed by computer. A fully automated technique for counting microaneurysms (MA) in these images was developed with a view to producing an objective, accurate and highly repeatable way of quantifying these lesions. Prior to any other image processing, a number of pre-processing stages were applied in order to compensate for non-uniformaties and to remove the background fluorescence component present in all the images. Matched filters modelled on two-dimensional Gaussian distributions were employed to detect MA in the 'shade-corrected' images. A binary image representation of the vascular network was constructed. This 'vessel mask', used in conjunction with the original match-filtered images, enabled MA to be detected by grey-level thresholding the filtered images. The resulting binary objects could then be counted by the computer as MA. The automated technique was assessed by comparing the computer's results for six fluorescein angiograms with MA counts obtained by ophthalmologists analysing both analogue and digital images. The performance of both man and machine were judged with respect to 'gold standards' compiled from prints of the original negatives. The best results were obtained by the clinicians analysing the analogue prints, although they differed greatly in their ability to detect microaneurysms. The computer performed better than the clinicians when they were counting MA in the digital images and produced highly repeatable results. To improve the performance of the automated technique, images were captured at approximately four times the previous spatial resolution and a smaller area of each image was analysed. Additionally, more complex image-processing techniques were employed to increase the accuracy of the computer analysis. Although the performance of the automated technique was improved, the computer results only matched those of the clinicians' analogue analyses for two of the images.

Thesis (Ph.D.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: leaf 205-210.

Thesis (PH. D.)--Michigan State University. Chemical Engineering, 2008. / Title from PDF t.p. (viewed on Sept. 6, 2009) Includes bibliographical references (p. 116-119). Also issued in print.