Orthokeratology (OK) is the reduction, modification or elimination of myopia through application of contact lenses. With the development of high Dk/t lens materials, overnight therapy has become the modality of choice for OK. Overnight OK lens wear has been previously investigated in terms of its efficacy to reduce myopia. However, the underlying effects of overnight OK lens wear on the human cornea have received less attention. As well as the clinical efficacy of overnight OK, this study investigated the effects of overnight OK on topographical corneal thickness and the overnight corneal edema response, and corneal tissue changes with overnight OK. Eighteen subjects participated as the OK lens-wearing group, wearing BE lenses (UltraVision, Brisbane, Queensland) in both eyes. A further ten subjects participated as control subjects, wearing conventional rigid lenses (J-Contour, UltraVision) in the right eye (RE) only. The left eye (LE) acted as a non-lens-wearing control. Both groups wore lenses overnight only, with no lens wear during the day. Measurements were conducted at baseline then on day 1, 4, 10, 30, 60, and 90 for the OK lens-wearing eyes; and up to day 30 for the control group, in the morning (after overnight lens wear) and in the evening (after 8-10 hours of lens removal). Variables measured included best vision sphere (BVS), unaided logMAR visual acuity (VA), refractive astigmatism, apical corneal power (ACP), simulated K readings (Medmont E300 corneal topographer), topographical corneal thickness (Holden-Payor optical pachometer), and keratocyte and endothelial cell densities (ConfoScan2 confocal microscope). Approximately 75% of myopia was corrected after the first night of OK lens wear and the changes in refractive error stabilised by day 10. By day 90, myopia reduction averaged 2.54 ?? 0.63 D. This was associated with significant improvement in unaided VA of about 82% after the first night of lens wear. There was no change in refractive astigmatism over the 3-month period. There was significant reduction in ACP in the OK lens-wearing eyes after the first night of lens wear, which accounted for more than 70% of the total ACP change over the 3-month period (RE: -2.16 ?? 0.53 D; LE: -2.11 ?? 0.86 D). There was significant central epithelial thinning (about 30%) and significant thickening (about 3%) in the mid-peripheral stroma in the OK lens-wearing eyes. Significant central epithelial thinning was found after the first night of lens wear while thickening in the mid-peripheral stroma reached statistical significance by day 4. Further analysis suggests that topographical corneal thickness changes account for the refractive error changes with overnight OK lens wear, rather than corneal bending. The central overnight stromal edema response was significantly reduced in the OK lens-wearing eyes (1.2 ?? 0.5%) to a level lower than in the conventional RGP (6.2 ?? 1.2%) and non-lens-wearing eyes (2.5 ?? 0.9%) in the control group. Mid-peripheral and peripheral stromal edema responses showed similar levels to those predicted based on lens Dk/t. A single overnight wear of BE and Paragon Corneal Refractive Therapy (CRT) lenses showed that the edema response to BE lens wear is significantly less than in the CRT lens-wearing eyes (BE: 2.5 ?? 0.7%; CRT 3.5 ?? 1.3%) immediately on eye opening. No significant changes were found in either central stromal keratocyte or endothelial cell densities in either OK or control groups over the study period. In conclusion, overnight OK lens wear induces significant reductions in myopia after the first night of lens wear associated with improvement in unaided VA. Overnight OK lens wear causes significant thinning in the central epithelium and significant mid-peripheral stromal thickening which results in flattening of the central cornea and steepening in the mid-periphery. Although there were no significant changes in central stromal keratocyte and endothelial cell densities, thinning of the central epithelial layer raises concerns regarding the safety of the procedure, especially with the alarming number of corneal infections reported recently in the literature.

Orthokeratology (OK) is the reduction, modification or elimination of myopia through application of contact lenses. With the development of high Dk/t lens materials, overnight therapy has become the modality of choice for OK. Overnight OK lens wear has been previously investigated in terms of its efficacy to reduce myopia. However, the underlying effects of overnight OK lens wear on the human cornea have received less attention. As well as the clinical efficacy of overnight OK, this study investigated the effects of overnight OK on topographical corneal thickness and the overnight corneal edema response, and corneal tissue changes with overnight OK. Eighteen subjects participated as the OK lens-wearing group, wearing BE lenses (UltraVision, Brisbane, Queensland) in both eyes. A further ten subjects participated as control subjects, wearing conventional rigid lenses (J-Contour, UltraVision) in the right eye (RE) only. The left eye (LE) acted as a non-lens-wearing control. Both groups wore lenses overnight only, with no lens wear during the day. Measurements were conducted at baseline then on day 1, 4, 10, 30, 60, and 90 for the OK lens-wearing eyes; and up to day 30 for the control group, in the morning (after overnight lens wear) and in the evening (after 8-10 hours of lens removal). Variables measured included best vision sphere (BVS), unaided logMAR visual acuity (VA), refractive astigmatism, apical corneal power (ACP), simulated K readings (Medmont E300 corneal topographer), topographical corneal thickness (Holden-Payor optical pachometer), and keratocyte and endothelial cell densities (ConfoScan2 confocal microscope). Approximately 75% of myopia was corrected after the first night of OK lens wear and the changes in refractive error stabilised by day 10. By day 90, myopia reduction averaged 2.54 ?? 0.63 D. This was associated with significant improvement in unaided VA of about 82% after the first night of lens wear. There was no change in refractive astigmatism over the 3-month period. There was significant reduction in ACP in the OK lens-wearing eyes after the first night of lens wear, which accounted for more than 70% of the total ACP change over the 3-month period (RE: -2.16 ?? 0.53 D; LE: -2.11 ?? 0.86 D). There was significant central epithelial thinning (about 30%) and significant thickening (about 3%) in the mid-peripheral stroma in the OK lens-wearing eyes. Significant central epithelial thinning was found after the first night of lens wear while thickening in the mid-peripheral stroma reached statistical significance by day 4. Further analysis suggests that topographical corneal thickness changes account for the refractive error changes with overnight OK lens wear, rather than corneal bending. The central overnight stromal edema response was significantly reduced in the OK lens-wearing eyes (1.2 ?? 0.5%) to a level lower than in the conventional RGP (6.2 ?? 1.2%) and non-lens-wearing eyes (2.5 ?? 0.9%) in the control group. Mid-peripheral and peripheral stromal edema responses showed similar levels to those predicted based on lens Dk/t. A single overnight wear of BE and Paragon Corneal Refractive Therapy (CRT) lenses showed that the edema response to BE lens wear is significantly less than in the CRT lens-wearing eyes (BE: 2.5 ?? 0.7%; CRT 3.5 ?? 1.3%) immediately on eye opening. No significant changes were found in either central stromal keratocyte or endothelial cell densities in either OK or control groups over the study period. In conclusion, overnight OK lens wear induces significant reductions in myopia after the first night of lens wear associated with improvement in unaided VA. Overnight OK lens wear causes significant thinning in the central epithelium and significant mid-peripheral stromal thickening which results in flattening of the central cornea and steepening in the mid-periphery. Although there were no significant changes in central stromal keratocyte and endothelial cell densities, thinning of the central epithelial layer raises concerns regarding the safety of the procedure, especially with the alarming number of corneal infections reported recently in the literature.

Orthokeratology (OK) is the reduction, modification or elimination of myopia through application of contact lenses. With the development of high Dk/t lens materials, overnight therapy has become the modality of choice for OK. Overnight OK lens wear has been previously investigated in terms of its efficacy to reduce myopia. However, the underlying effects of overnight OK lens wear on the human cornea have received less attention. As well as the clinical efficacy of overnight OK, this study investigated the effects of overnight OK on topographical corneal thickness and the overnight corneal edema response, and corneal tissue changes with overnight OK. Eighteen subjects participated as the OK lens-wearing group, wearing BE lenses (UltraVision, Brisbane, Queensland) in both eyes. A further ten subjects participated as control subjects, wearing conventional rigid lenses (J-Contour, UltraVision) in the right eye (RE) only. The left eye (LE) acted as a non-lens-wearing control. Both groups wore lenses overnight only, with no lens wear during the day. Measurements were conducted at baseline then on day 1, 4, 10, 30, 60, and 90 for the OK lens-wearing eyes; and up to day 30 for the control group, in the morning (after overnight lens wear) and in the evening (after 8-10 hours of lens removal). Variables measured included best vision sphere (BVS), unaided logMAR visual acuity (VA), refractive astigmatism, apical corneal power (ACP), simulated K readings (Medmont E300 corneal topographer), topographical corneal thickness (Holden-Payor optical pachometer), and keratocyte and endothelial cell densities (ConfoScan2 confocal microscope). Approximately 75% of myopia was corrected after the first night of OK lens wear and the changes in refractive error stabilised by day 10. By day 90, myopia reduction averaged 2.54 ?? 0.63 D. This was associated with significant improvement in unaided VA of about 82% after the first night of lens wear. There was no change in refractive astigmatism over the 3-month period. There was significant reduction in ACP in the OK lens-wearing eyes after the first night of lens wear, which accounted for more than 70% of the total ACP change over the 3-month period (RE: -2.16 ?? 0.53 D; LE: -2.11 ?? 0.86 D). There was significant central epithelial thinning (about 30%) and significant thickening (about 3%) in the mid-peripheral stroma in the OK lens-wearing eyes. Significant central epithelial thinning was found after the first night of lens wear while thickening in the mid-peripheral stroma reached statistical significance by day 4. Further analysis suggests that topographical corneal thickness changes account for the refractive error changes with overnight OK lens wear, rather than corneal bending. The central overnight stromal edema response was significantly reduced in the OK lens-wearing eyes (1.2 ?? 0.5%) to a level lower than in the conventional RGP (6.2 ?? 1.2%) and non-lens-wearing eyes (2.5 ?? 0.9%) in the control group. Mid-peripheral and peripheral stromal edema responses showed similar levels to those predicted based on lens Dk/t. A single overnight wear of BE and Paragon Corneal Refractive Therapy (CRT) lenses showed that the edema response to BE lens wear is significantly less than in the CRT lens-wearing eyes (BE: 2.5 ?? 0.7%; CRT 3.5 ?? 1.3%) immediately on eye opening. No significant changes were found in either central stromal keratocyte or endothelial cell densities in either OK or control groups over the study period. In conclusion, overnight OK lens wear induces significant reductions in myopia after the first night of lens wear associated with improvement in unaided VA. Overnight OK lens wear causes significant thinning in the central epithelium and significant mid-peripheral stromal thickening which results in flattening of the central cornea and steepening in the mid-periphery. Although there were no significant changes in central stromal keratocyte and endothelial cell densities, thinning of the central epithelial layer raises concerns regarding the safety of the procedure, especially with the alarming number of corneal infections reported recently in the literature.

Thesis (M.S.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed Feb. 15, 2008). Includes bibliographical references (p. 33-37).

Thesis (M.S.)--University of Adelaide, Dept. of Surgery, 2004. / "December 2003" Bibliography: leaves 82-99.

Thesis (Ph. D.)--Uniformed Services University of the Health Sciences, 2007. / Typescript (photocopy).

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 177-187).

Baseado na carência de documentação com respeito ao endotélio da córnea de ovinos, a pesquisa teve como objetivo documentar o endotélio corneal de ovinos em diferentes faixas etárias – jovem, adulto e velho – utilizando a microscopia especular. Logo, buscou-se investigar o efeito da idade sobre a morfologia e morfometria do endotélio da córnea de ovinos. O endotélio corneano foi avaliado com auxilio do microscópio especular de contato. No total, foram avaliados 18 ovinos (Ovis aires) neste estudo. Os animais foram distribuídos em três grupos de 6 animais cada um em função da idade. O grupo I continha animais com idade de 6 meses; o grupo II, animais com idade de 2 a 4 anos; e o grupo III continha animais de 5 a 8 anos. Para a avaliação do endotélio corneal foram levados em consideração a densidade de células endoteliais (DCE), a área celular média, o polimegatismo e o pleomorfismo. Os resultados encontrados revelaram a diminuição na DCE em córneas de ovinos normais com o avanço da idade bem como o aumento da área das células endoteliais e do pleomorfismo. O presente trabalho mostrou que os parâmtros endoteliais valiados sofrem alterações decorrentes da idade. / Based on the lack of information on the corneal endothelium of ovine, the objective of this research was to evaluate the corneal endothelium of sheep in different age groups – young, adult and old - using the specular microscope. So the aim of this study was to investigate the effect of age on morphology and morphometry corneal endothelium of sheep. The corneal endothelium was evaluated with the help of a contact specular microscope. A total of 18 sheep (Ovis aires) were evaluated in this study. The sheep mob was divided into three groups of six animals each according to age. Group I contained animals 6 months old, group II contained animals from 2 to 4 years old and group III contained animals from 5 to 8 years old. To evaluate corneal endothelium we estimated the endothelial cell density (ECD), the average cell area, polymegathism and pleomorphism. The results revealed on ECD decrease in corneas of normal sheep with advancing age, as well as a corresponding increase in endothelial cell area and pleomorphism. The present work suggests that the endothelial parameters evaluated change with advancing age.

Made available in DSpace on 2016-02-05T18:29:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-04-18. Added 1 bitstream(s) on 2016-02-05T18:32:36Z : No. of bitstreams: 1 000854739_20170117.pdf: 187177 bytes, checksum: 4b038159e9c2ea2e69ae07917b92511a (MD5) Bitstreams deleted on 2017-01-20T11:08:15Z: 000854739_20170117.pdf,. Added 1 bitstream(s) on 2017-01-20T11:08:56Z : No. of bitstreams: 1 000854739.pdf: 1172109 bytes, checksum: 4faa6227f28c9d27263c09ed1232ca6f (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Este trabalho teve como objetivo determinar o poder dióptrico da lente intraocular (LIO) de miniporcos brasileiro e as dimensões do bulbo do olho. Foram utilizados 17 animais (34 olhos) clinicamente sadios, adultos, machos e fêmeas com peso médio de 70 kg. Em todos os olhos, foram realizadas a ultrassonografia modo A, ceratometria e a medida da distância limbo a limbo; variáveis para o cálculo do poder dióptrico da lente intraocular. Este foi obtido utilizando-se diferentes fórmulas e o software Holladay IOL Consultant®. Foram comparadas, adicionalmente, as mensurações oculares quanto ao sexo, lateralidade do olho e as diferentes fórmulas utilizadas (Haigis, Hoffer Q, SRK/T, Holladay I e Holladay II). Na comparação entre o sexo e lateralidade do olho, não houve diferença nas variáveis biométricas e poder da lente intraocular. A aplicação das fórmulas empregadas (Haigis, Holladay II, Holladay I, SRK/T e Hoffer Q) possibilita o cálculo do poder da lente intraocular nesta espécie, e o valor observado variou entre 39,58±2,15 e 46,6±2,81 dioptrias Os miniporcos desempenham importante e crescente papel como modelo experimental para a prática e estudos de procedimento oftalmológico, especialmente relacionados ao seu menor porte e facilidade no manejo de experimentos de longa duração / The aim of this study is to determine the refractive power of intraocular lens (IOL) of Brazilian minipigs and the dimensions of the eyeball. Total of 17 animals (34 eyes) healthy, adult, males and females, with average weight of 70kg were used. For every eye, A-mode ultrasound, keratometry and the measure of limbo-to-limbo distance were conducted; all of them variables for calculating the refractive power of the IOL. That value was obtained using different formulas and Holladay IOL Consultant® Software. Were additionally compared the ocular measurements for sex, laterality of the eye and the different formulas used in this study (Haigis, Hoffer Q, SRK / T, Holladay I and Holladay II). In the comparison between sex and laterality of the eye, there is no difference in biometric variables and power of the IOL. The application of the employed formulas (Haigis, Holladay II, Hollada I, SRK / T and Hoffer Q) allows the IOL power calculation of this specie, and the observed value ranged between 39,58±2,15 and 46,60±2,81 diopters. The minipig has an important and growing role as an experimental model for the study and practice of ophthalmic procedure, specially related to their smaller size and easily management in long term experiments

Made available in DSpace on 2015-04-09T12:28:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-15Bitstream added on 2015-04-09T12:47:39Z : No. of bitstreams: 1 000815064_20150715.pdf: 50300 bytes, checksum: 8f441f19a66d1fbc8d9e0f038cc01e8b (MD5) Bitstreams deleted on 2015-08-03T12:20:59Z: 000815064_20150715.pdf,. Added 1 bitstream(s) on 2015-08-03T12:22:19Z : No. of bitstreams: 1 000815064.pdf: 538304 bytes, checksum: 5ea43b7b562fe3e195c422aa12124413 (MD5) / O omento, tecido gorduroso rico em células tronco mesenquimais, expressa fatores de crescimento, que atuam na regeneração tecidual, tornando-o atrativo para utilização em medicina regenerativa. Não há relatos, todavia, quanto à investigação sobre células do omento na cirurgia regenerativa em oftalmologia. Avaliaram-se os efeitos clínicos e à microscópia do omento com membrana amniótica na reparação da córnea de coelhos submetidos a ceratectomia. Duas modalidades foram avaliadas. Na primeira, o omento foi coberto com membrana amniótica imediatamente à sua implantação na córnea (grupo OM); na segunda, a membrana amniótica foi colonizada por células progenitoras extraídas do omento e transplantadas para a córnea (grupo OMC). Os efeitos clínicos foram avaliados a partir de dados coletados por até 60 dias de pós-operatório. A incidência e a prevalência de quemose foram maiores no grupo OM (p<0,05). O grupo OMC mostrou mais incidência de blefarospasmo (p<0,001). À microscopia de luz, encontrou-se reparação corneal gradativa em ambos os grupos, com reepitelização ao 100 de pós-operatótio. Aos 60 dias da avaliação, todas as córneas estavam reparadas, entretanto, no grupo OMC constatou-se vascularização. Proliferação celular acentuada foi observada com o ki-67, nos estágios finais do processo de reparação de córneas que receberam MA contendo células do omento (grupo OMC). Somente no grupo OMC, a reparação corneal sem tranparência foi alcançada / The omentum, a fatty tissue rich in mesenchymal stem cells, expresses growth factors that act in tissue regeneration, making it attractive for use in regenerative medicine. To our knowledge, reports that investigate the use of omentum cells in ophthalmology have yet to be published. The purpose of this study was to assess the clinical and microscopic effects of omentum associated with amniotic membrane on the repair of rabbit cornea submitted to keratectomy. Two methods were evaluated; in the first, the omentum was covered with amniotic membrane immediately following its implantation on the cornea (OM group), while in the second, the amniotic membrane was colonized by omental progenitor cells and transplanted to the cornea (OMC group). Clinical parameters were evaluated from data collected up to 60 days postoperatively. The incidence and prevalence of chemosis were higher in the OM group (p<0.05). The OMC group showed greater incidence of blepharospasm (p<0.001). Under light microscopy, the absence of epithelium in the lesioned area and stromal disorganization were observed in the early postoperative period. After 60 days of evaluation, all the corneas were repaired. Intense cell proliferation was detected with Ki-67, in the final stages of the repair process, where amniotic membrane containing omental progenitor cells was transplanted to the corneas. The use of omentum and its cells, in association with amniotic membrane, favored the repair of the cornea and did not induce complications