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1.
Lasers Med Sci ; 31(4): 659-64, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26868029

RESUMO

The aim of this study is to establish and to prove a new lenticule shape for the treatment of hyperopia using a 500 kHz femtosecond laser and the femtosecond lenticule extraction (ReLEx FLEx) technique. Improved lenticule shapes with a large transition zone of at least 2 mm adjusted to the 5.75 mm optical zone were designed. A prospective pilot study on nine eyes of five patients who underwent an uncomplicated FLEx using VisuMax femtosecond laser (Carl Zeiss Meditec AG) for spherical hyperopia was performed. Patients' mean age was 55.5 years, and the preoperative manifest spherical equivalent (SE) was +1.82 D (range +1.25 to +3.00 D). Because of the presbyopic age and in order to compensate for a possible regression, the treatment was aimed at low myopia (mean target SE was -0.88 D with a mean treatment refraction of +2.69 D). At the last follow-up, after 9 months, 33% were within ±0.50 D and 78% within ±1.00 D of intended correction. Thirty-three percent lost one line, and 11% gained one line corrected distance visual acuity (CDVA). On average, the centre of the optical zone was 0.34 ± 0.17 mm from the corneal vertex. No adverse effects were observed. This pilot study confirms that the improved lenticule's design with a large optical and transition zone can achieve good centration and acceptable results for spherical hyperopia using FLEx. The next steps are to extend the study to spherocylindrical hyperopic treatments and to increase the number of eyes for better assessment of refractive outcome.


Assuntos
Cirurgia da Córnea a Laser/normas , Hiperopia/cirurgia , Adulto , Córnea/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Melhoria de Qualidade , Resultado do Tratamento , Acuidade Visual
2.
Sci Total Environ ; 921: 170750, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38336073

RESUMO

Anthropogenic disturbances, including extraction of natural resources and development of alternative energy, are reducing and fragmenting habitat for wildlife across the globe. Effects of those disturbances have been explored by studying populations that migrate through oil and gas fields or alternative energy facilities. Extraction of minerals, including precious metals and lithium, is increasing rapidly in remote areas, which results in dramatically altered landscapes in areas of resident populations of wildlife. Our goal was to examine how a resident population of American pronghorn (Antilocapra americana) in the Great Basin ecosystem selected resources near a large-scale disturbance year around. We investigated how individuals selected resources around a large, open-pit gold mine. We classified levels of disturbance associated with the mine, and used a random forest model to select ecological covariates associated with habitat selection by pronghorn. We used resource selection functions to examine how disturbances affected habitat selection by pronghorn both annually and seasonally. Pronghorn strongly avoided areas of high disturbance, which included open pits, heap leach fields, rock disposal areas, and a tram. Pronghorn selected areas near roads, although selection was strongest about 2 km away. We observed relatively broad variation among individuals in selection of resources, and how they responded to the mine. The Great Basin is a mineral-rich area that continues to be exploited for natural resources, especially minerals. Sagebrush-dependent species, including pronghorn, that rely on this critical habitat were directly affected by that transformation of the landscape, which is likely to increase with expansion of the mine. As extraction of minerals from remote landscapes around the world continues to fragment habitats for wildlife, increasing our understanding of impacts of those changes on behaviors of wildlife before populations decline, may assist in the mitigation and minimization of negative impacts on mineral-rich landscapes and on wildlife populations.


Assuntos
Ecossistema , Ouro , Humanos , Animais , Conservação dos Recursos Naturais/métodos , Animais Selvagens , Ruminantes , Minerais
3.
Graefes Arch Clin Exp Ophthalmol ; 251(1): 349-55, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22695934

RESUMO

BACKGROUND: This prospective study focused on the results of a novel method for refractive correction, femtosecond lenticule extraction (ReLEx®) in hyperopia, and reports the first 47 eyes. METHODS: In 47 hyperopic eyes (26 patients), both a flap and a lenticule of intrastromal corneal tissue were simultaneously cut utilizing the Carl Zeiss Meditec AG (CZM) 200 kHz VisuMax femtosecond laser system. Thereafter, the lenticule was manually removed and the flap repositioned. Forty two out of 47 hyperopic eyes of the treatment group completed the final 9-month follow-up. The patients mean age was 42.3 (±9.0) years. Their mean preoperative spherical equivalent (SE) was +2.8 (±1.3) D. UCVA and BSCVA after 9 months, objective and manifest refraction, as well as slit-lamp examination and side-effects were evaluated. RESULTS: Nine months postoperatively, 64 % of eyes treated were within ±1.0 D, and 38 % of eyes within ±0.5 D of intended correction. One of 47 eyes (2.1 %) lost more than 2 Snellen lines; none of the eyes had a UCVA less than 0.5. However, stability was less impressive when compared to ReLEx for the correction of myopia. CONCLUSIONS: First data suggest that ReLEx is a feasible and effective procedure for treatment of hyperopia. Further research is needed to improve predictability and effectiveness of the procedure for the correction of hyperopia.


Assuntos
Substância Própria/cirurgia , Hiperopia/cirurgia , Terapia a Laser/métodos , Retalhos Cirúrgicos , Adulto , Topografia da Córnea , Estudos de Viabilidade , Feminino , Humanos , Hiperopia/fisiopatologia , Terapia a Laser/instrumentação , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Refração Ocular/fisiologia , Resultado do Tratamento , Acuidade Visual/fisiologia , Adulto Jovem
4.
Graefes Arch Clin Exp Ophthalmol ; 251(8): 1967-77, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23811991

RESUMO

PURPOSE: To examine the use of a modified Hartmann-Shack wave front aberrometer (WASCA; Carl Zeiss Meditec AG, Germany) to measure objective stray light caused by forward light scatter from the anterior segment of the human eye. SETTING: HELIOS Klinikum Erfurt/Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Germany. METHOD: Scatter parameters, including the Michelson contrast and cross-sectional area at half height (CAHM) were examined in Hartmann-Shack images from ten subjects with a cataract in one eye and an intraocular lens (IOL) in the other. The parameters were compared between each eye. Light scatter was then measured in 40 healthy subjects (age range, 23-75 years) with spherical ametropia ranging from -0.25 to 0.25 diopters. The subjects were divided into three age groups; 23-35, 36-50, and 51-75 years. Light scatter was also measured using four alternative methods. RESULTS: CAHM and contrast were significantly different between the eyes with the cataract and the IOL (P = 0.007 and P = 0.004, respectively). CAHM (r = 0.557, P < 0.001) and contrast (r = -0.467, P < 0.001) were both significantly correlated with age. There were significant differences in CAHM and contrast between the age groups. CONCLUSION: The modified wave front aberrometer can be used to measure stray light, although its diagnostic sensitivity in individual patients must be improved.


Assuntos
Aberrometria/instrumentação , Segmento Anterior do Olho/efeitos da radiação , Monitoramento de Radiação/métodos , Espalhamento de Radiação , Adulto , Idoso , Idoso de 80 Anos ou mais , Catarata/etiologia , Humanos , Lentes Intraoculares , Luz , Pessoa de Meia-Idade , Pseudofacia/etiologia , Adulto Jovem
5.
Mov Ecol ; 11(1): 20, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37020241

RESUMO

Animals select habitats based on food, water, space, and cover. Each of those components are essential to the ability of an individual to survive and reproduce in a particular habitat. Selection of resources is linked to reproductive fitness and individuals likely vary in how they select resources relative to their reproductive state: during pregnancy, while provisioning young when nutritional needs of the mother are high, but offspring are vulnerable to predation, or if they lose young to mortality. We investigated the effects of reproductive state on selection of resources by maternal female desert bighorn sheep (Ovis canadensis nelsoni) by comparing selection during the last trimester of gestation, following parturition when females were provisioning dependent young, and if the female lost an offspring. We captured, and recaptured each year, 32 female bighorn sheep at Lone Mountain, Nevada, during 2016-2018. Captured females were fit with GPS collars and those that were pregnant received vaginal implant transmitters. We used a Bayesian approach to estimate differences in selection between females provisioning and not provisioning offspring, as well as the length of time it took for females with offspring to return levels of selection similar to that observed prior to parturition. Females that were not provisioning offspring selected areas with higher risk of predation, but greater nutritional resources than those that were provisioning dependent young. When females were provisioning young immediately following parturition, females selected areas that were safe from predators, but had lower nutritional resources. Females displayed varying rates of return to selection strategies associated with access to nutritional resources as young grew and became more agile and less dependent on mothers. We observed clear and substantial shifts in selection of resources associated with reproductive state, and females exhibited tradeoffs in favor of areas that were safer from predators when provisioning dependent young despite loss of nutritional resources to support lactation. As young grew and became less vulnerable to predators, females returned to levels of selection that provided access to nutritional resources to restore somatic reserves lost during lactation.

6.
Graefes Arch Clin Exp Ophthalmol ; 250(12): 1813-25, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22371023

RESUMO

BACKGROUND: In a single-blinded study, optical side-effects of a potential femtosecond (fs)-laser therapy in presbyopic human lenses were tested. Simulation of this therapy was carried out by applying fs-laser patterns into standard contact lenses (CL). METHODS: In the first part of the study, the influence of the numerical aperture on optical side-effects was investigated by comparing a typical fs-LASIK configuration to a fs-presbyopia treatment (n = 11). The second part focused on a possible improvement of visual performance by comparing a regular grid pattern to a randomly chosen spacing of the laser spots (n = 16). Visual acuity was measured with ETDRS charts, contrast sensitivity with F.A.C.T. charts and mesopic vision with Mesotest II. Forward scattered light was measured with the C-Quant (both instruments: Oculus Optikgeräte GmbH, Germany). A questionnaire detected subjective quality of vision. Differences between laser-treated and untreated CL and among the modifications were analyzed. RESULTS: The laser-treated and standard CL indicated no significant difference in visual acuity, contrast sensitivity and mesopic vision without glare. While wearing modified lenses with a regular grid, quality of vision decreased significantly by means of mesopic vision with glare and subjective straylight. These modifications also caused an impairment of subjective quality of vision. In contrast, there was no significant difference between the random pattern and standard CL. CONCLUSION: The increase of optical side-effects was reproducibly dependent on the geometry of the laser-structure. A randomized grid induced the least limitation. The study results are useful for planning possible laser-patterns in fs-laser therapy of the presbyopic lens.


Assuntos
Lentes de Contato , Ceratomileuse Assistida por Excimer Laser In Situ , Lasers de Excimer/efeitos adversos , Presbiopia/cirurgia , Adulto , Sensibilidades de Contraste/fisiologia , Feminino , Humanos , Luz , Masculino , Visão Mesópica/fisiologia , Estudos Prospectivos , Espalhamento de Radiação , Método Simples-Cego , Inquéritos e Questionários , Transtornos da Visão/etiologia , Acuidade Visual/fisiologia , Adulto Jovem
7.
J Refract Surg ; 38(12): 760-769, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36476297

RESUMO

PURPOSE: To investigate the safety and effectiveness of small incision lenticule extraction (SMILE) in patients who have hyperopia with or without astigmatism. METHODS: This was a prospective multicenter trial including 374 eyes of 199 patients treated by SMILE for hyperopia using the VisuMax femtosecond laser (Carl Zeiss Meditec AG). Inclusion criteria were sphere up to +6.00 diopters (D), cylinder up to 5.00 D, and maximum hyperopic meridian up to +7.00 D, with preoperative corrected distance visual acuity (CDVA) of 20/25 or better. The optical zone was 6.3 mm with a transition zone of 2 mm. The minimum lenticule thickness was set at 25 µm in the center and at 10 µm at the edge. Patients were examined at 1 day, 1 week, and 1, 3, 6, 9, and 12 months after surgery. Standard refractive surgery outcomes analysis was performed. RESULTS: The preoperative spherical equivalent was +3.20 ± 1.48 D (range: +0.25 to +6.50 D). At the 12-month follow-up visit, 81% of eyes treated were within ±0.50 D and 93% of eyes were within ±1.00 D of intended correction. A total of 1.2% of eyes lost two or more lines of CDVA at the 12-month follow-up visit, and 83% were at least 20/20, corresponding to a safety index of 1.005 at 12 months. Of the 219 eyes with plano target, 68.8% had an uncorrected distance visual acuity of 20/20 or better and 88% were at least 20/25 uncorrected at 12 months. There were no statistically significant changes in contrast sensitivity. CONCLUSIONS: SMILE was found to be an effective treatment method for the correction of compound hyperopic astigmatism, demonstrating a high level of efficacy, predictability, safety, and stability. [J Refract Surg. 2022;38(12):760-769.].


Assuntos
Hiperopia , Humanos , Estudos Prospectivos , Hiperopia/cirurgia
8.
J Clin Med ; 11(17)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36079030

RESUMO

BACKGROUND: To investigate whether vaccination against SARS-CoV-2 is associated with the onset of retinal vascular occlusive disease (RVOD). METHODS: In this multicentre study, data from patients with central and branch retinal vein occlusion (CRVO and BRVO), central and branch retinal artery occlusion (CRAO and BRAO), and anterior ischaemic optic neuropathy (AION) were retrospectively collected during a 2-month index period (1 June-31 July 2021) according to a defined protocol. The relation to any previous vaccination was documented for the consecutive case series. Numbers of RVOD and COVID-19 vaccination were investigated in a case-by-case analysis. A case-control study using age- and sex-matched controls from the general population (study participants from the Gutenberg Health Study) and an adjusted conditional logistic regression analysis was conducted. RESULTS: Four hundred and twenty-one subjects presenting during the index period (61 days) were enrolled: one hundred and twenty-one patients with CRVO, seventy-five with BRVO, fifty-six with CRAO, sixty-five with BRAO, and one hundred and four with AION. Three hundred and thirty-two (78.9%) patients had been vaccinated before the onset of RVOD. The vaccines given were BNT162b2/BioNTech/Pfizer (n = 221), followed by ChadOx1/AstraZeneca (n = 57), mRNA-1273/Moderna (n = 21), and Ad26.COV2.S/Johnson & Johnson (n = 11; unknown n = 22). Our case-control analysis integrating population-based data from the GHS yielded no evidence of an increased risk after COVID-19 vaccination (OR = 0.93; 95% CI: 0.60-1.45, p = 0.75) in connection with a vaccination within a 4-week window. CONCLUSIONS: To date, there has been no evidence of any association between SARS-CoV-2 vaccination and a higher RVOD risk.

9.
Graefes Arch Clin Exp Ophthalmol ; 249(9): 1417-24, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21240524

RESUMO

BACKGROUND: To determine the surface characteristics of human corneal lenticules after femtosecond laser surgery for myopia. METHODS: The Carl Zeiss Meditec AG VisuMax® femtosecond laser system was used for refractive correction called Femtosecond Lenticule Extraction on 24 myopic eyes. The surface regularity on the refractive corneal lenticules recovered was evaluated by assessing scanning electron microscopy images using an established scoring system. Three different energy levels 150, 180, and 195 nJ were compared (n = 8 in each group). RESULTS: Surface irregularities were caused by tissue bridges, cavitation bubbles, or scratches. The surface regularity index (R(2) = 0.74) decreased as pulse energy increased. The average surface regularity score obtained was 7.5 for 150 nJ, 7.25 for 180 nJ, and 6.25 for 195 nJ. CONCLUSIONS: The human corneal lenticules created with the VisuMax® femtosecond laser system are of predictable, good-quality surface. This study shows the influence of pulse energy on surface regularity in human eyes. Further studies should focus on optimization of laser parameters as well as surgical technique to improve the regularity of the corneal stromal bed and so make the advantages of the femtosecond laser technology over conventional techniques clearer in the future.


Assuntos
Córnea/cirurgia , Córnea/ultraestrutura , Cirurgia da Córnea a Laser/métodos , Miopia/cirurgia , Procedimentos Cirúrgicos Refrativos/métodos , Adulto , Feminino , Humanos , Masculino , Microscopia Eletrônica de Varredura , Refratometria , Propriedades de Superfície , Retalhos Cirúrgicos , Adulto Jovem
10.
Graefes Arch Clin Exp Ophthalmol ; 249(10): 1567-73, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21853231

RESUMO

BACKGROUND: To investigate the long-term stability and possible cataractogenesis after femtosecond laser treatment of the crystalline lens. METHODS: The crystalline lenses of ten Göttingen minipigs® underwent femtosecond laser treatment. During a subsequent 1-year follow-up, the pigs were monitored by means of slit-lamp examination of the anterior segment and Scheimpflug imaging of the lens. RESULTS: No laser-induced cataractogenesis was observed during the 1-year follow-up. The laser pattern showed a stable appearance under all examination devices. CONCLUSION: Femtosecond laser treatment seems to be no trigger for cataract formation. Moreover, the long-term stability of the laser pattern makes it suitable for applications such as presbyopia treatment.


Assuntos
Catarata/patologia , Terapia a Laser/instrumentação , Cristalino/cirurgia , Animais , Catarata/etiologia , Modelos Animais de Doenças , Feminino , Seguimentos , Cristalino/patologia , Suínos , Porco Miniatura , Fatores de Tempo , Resultado do Tratamento
11.
Ophthalmic Res ; 46(2): 107-12, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21311205

RESUMO

PURPOSE: To determine the surface characteristics of porcine corneal lenticules after Femtosecond Lenticule Extraction. METHODS: The Carl Zeiss Meditec AG VisuMax® femtosecond laser system was used to create refractive corneal lenticules on 10 freshly isolated porcine eyes. The surface regularity on the corneal lenticules recovered was evaluated by assessing scanning electron microscopy images using an established scoring system. RESULTS: All specimens yielded comparable score results of 5-7 points (SD = 0.59) per lenticule (score range minimum 4 to maximum 11 points). Surface irregularities were caused by tissue bridges, cavitation bubbles or scratches. CONCLUSION: The Femtosecond Lenticule Extraction procedure is capable of creating corneal lenticules of predictable surface quality. However, future studies should focus on the optimization of laser parameters as well as surgical technique to improve the regularity of the corneal stromal bed.


Assuntos
Córnea/ultraestrutura , Ceratomileuse Assistida por Excimer Laser In Situ , Lasers de Excimer , Animais , Córnea/cirurgia , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Retalhos Cirúrgicos , Suínos
12.
Graefes Arch Clin Exp Ophthalmol ; 248(7): 1019-27, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20130899

RESUMO

PURPOSE: To report the 6-month results of a new method of refractive correction, femtosecond lenticule extraction (FLEx), and the preliminary outcomes in the first 108 eyes. METHODS: In this prospective study, a flap and a lenticule of intrastromal corneal tissue were cut simultaneously using a femtosecond laser. Thereafter, the lenticule was removed manually and the flap repositioned. One hundred and seven of 108 myopic eyes of 56 patients in the treatment group completed the final 6 months of follow-up. The patients' mean age was 35 years. The preoperative mean spherical equivalent (SE) was -4.59 +/- 1.3 diopters (D). The uncorrected visual acuity and the best spectacle-corrected visual acuity after 6 months, objective and manifest refractions, results of slit-lamp examination, the side effects, and the responses to a questionnaire are reported. RESULTS: Six months postoperatively, the mean SE was -0.19 +/- 0.47 D; 98.1% of treated eyes were within +/-1.0 D, and 74.8% of eyes within +/-0.5 D of the intended correction. Eight (7.4%) of 108 eyes lost one line of Snellen VA, one (0.9%) eye lost two Snellen lines, 46 eyes (43%) gained one line, ten eyes (9.3%) gained two Snellen lines, and the VA remained unchanged in 42 (39.3%) eyes. The patient responses to a standardized questionnaire indicated that 97.1% of patients were satisfied with the obtained results and would undergo the procedure again. CONCLUSION: FLEx appears to be a safe and promising corneal refractive procedure for correcting myopia.


Assuntos
Substância Própria/cirurgia , Cirurgia da Córnea a Laser/métodos , Miopia/cirurgia , Acuidade Visual , Adulto , Astigmatismo/cirurgia , Seguimentos , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Prospectivos , Refração Ocular , Retalhos Cirúrgicos , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
13.
J Mammal ; 101(5): 1244-1256, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-33335453

RESUMO

Bighorn sheep (Ovis canadensis) can live in extremely harsh environments and subsist on submaintenance diets for much of the year. Under these conditions, energy stored as body fat serves as an essential reserve for supplementing dietary intake to meet metabolic demands of survival and reproduction. We developed equations to predict ingesta-free body fat in bighorn sheep using ultrasonography and condition scores in vivo and carcass measurements postmortem. We then used in vivo equations to investigate the relationships between body fat, pregnancy, overwinter survival, and population growth in free-ranging bighorn sheep in California and Nevada. Among 11 subpopulations that included alpine winter residents and migrants, mean ingesta-free body fat of lactating adult females during autumn ranged between 8.8% and 15.0%; mean body fat for nonlactating females ranged from 16.4% to 20.9%. In adult females, ingesta-free body fat > 7.7% during January (early in the second trimester) corresponded with a > 90% probability of pregnancy and ingesta-free body fat > 13.5% during autumn yielded a probability of overwinter survival > 90%. Mean ingesta-free body fat of lactating females in autumn was positively associated with finite rate of population increase (λ) over the subsequent year in bighorn sheep subpopulations that wintered in alpine landscapes. Bighorn sheep with ingesta-free body fat of 26% in autumn and living in alpine environments possess energy reserves sufficient to meet resting metabolism for 83 days on fat reserves alone. We demonstrated that nutritional condition can be a pervasive mechanism underlying demography in bighorn sheep and characterizes the nutritional value of their occupied ranges. Mountain sheep are capital survivors in addition to being capital breeders, and because they inhabit landscapes with extreme seasonal forage scarcity, they also can be fat reserve obligates. Quantifying nutritional condition is essential for understanding the quality of habitats, how it underpins demography, and the proximity of a population to a nutritional threshold.

14.
J Refract Surg ; 25(4): 350-6, 2009 04.
Artigo em Inglês | MEDLINE | ID: mdl-19431925

RESUMO

PURPOSE: To assess the efficacy, safety, and predictability of the VisuMax femtosecond laser (Carl Zeiss Meditec). METHODS: In a prospective, multicenter clinical trial, 32 eyes of 17 patients underwent LASIK and flap creation with the VisuMax femtosecond laser and ablation with the MEL 80 excimer laser (Carl Zeiss Meditec). Mean patient age was 35 years (range: 23 to 52 years). Mean preoperative spherical equivalent refraction was -4.04 +/- 1.39 diopters (D) (range: -1.50 to -7.25 D), and the planned flap thickness was 110, 120, 140, and 150 microm. RESULTS: At the 3-month postoperative examination, all eyes had best spectacle-corrected visual acuity of 20/25 and uncorrected visual acuity (UCVA) of 20/40; 91% of eyes reached UCVA of 20/20 or better. Ninety-four percent of eyes were within +/- 0.50 D of the planned correction. Complications were limited to one case of suction loss, and no other adverse events were noted at 3 months. The flaps were planar and the mean achieved central flap thickness was 118 +/-9.2 microm for an attempted thickness of 120 microm. CONCLUSIONS: The investigators achieved LASIK outcomes exceeding the US Food and Drug Administration guidelines for refractive procedures in this series of myopic eyes using the VisuMax femtosecond laser and MEL 80 excimer laser. The curved contact lens of the applanation glass combined with low suction permitted continuous fixation during treatment.


Assuntos
Substância Própria/cirurgia , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Lasers de Excimer/uso terapêutico , Miopia/cirurgia , Retalhos Cirúrgicos , Adulto , Substância Própria/patologia , Feminino , Seguimentos , Humanos , Ceratomileuse Assistida por Excimer Laser In Situ/instrumentação , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Complicações Pós-Operatórias , Estudos Prospectivos , Refração Ocular/fisiologia , Inquéritos e Questionários , Tomografia de Coerência Óptica , Resultado do Tratamento , Acuidade Visual/fisiologia , Adulto Jovem
15.
J Refract Surg ; 25(11): 1005-11, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19921769

RESUMO

PURPOSE: To investigate the position and stability of the crystalline lens after application of a suction device containing a contact lens and a vacuum unit for the treatment of presbyopia using a femtosecond laser. METHODS: Twenty presbyopic (44.4+/-4.3 years) and 5 pre-presbyopic patients (31.6+/-3.8 years) were included. The anterior chamber depth, along with the position of the lens, was investigated before and after application of the suction device with optical coherence tomography (Visante OCT; Carl Zeiss Meditec AG). The type of suction device is routinely used for femtosecond LASIK with the VisuMax laser (Carl Zeiss Meditec AG). RESULTS: In both groups, there was a reduction in anterior chamber depth of approximately 700 microm due to the suction device, and the anterior chamber depth achieved was stable. The maximum variation was 160 microm. At the periphery of the crystalline lens, there were movements up to 310 microm axially and 470 microm laterally. CONCLUSIONS: The study proves that once the suction device has been applied, the crystalline lens is stable enough to undergo presbyopic laser therapy. However, the reduction in anterior chamber depth induced by the suction device showed significant individual variation. The exact position of the lens should therefore be measured immediately before laser surgery.


Assuntos
Câmara Anterior/patologia , Lasers de Excimer/uso terapêutico , Cristalino/patologia , Presbiopia/cirurgia , Sucção/instrumentação , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tomografia de Coerência Óptica
16.
J Refract Surg ; 35(11): 707-711, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31710372

RESUMO

PURPOSE: To evaluate the 10-year results of femtosecond lenticule extraction (FLEx) for treatment of myopia and myopic astigmatism. METHODS: This long-term follow-up of a prospective clinical trial was conducted at HELIOS Klinikum Erfurt and Phillips University of Marburg, Germany. In 2006, 108 eyes underwent the FLEx procedure. All patients were invited for reexamination 10 years after FLEx treatment for myopia and astigmatism. Visual acuity, objective and manifest refraction, intraocular pressure, and slit-lamp examination and side effects were documented. Main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuity, objective and manifest refraction, and slit-lamp examination and side effects. RESULTS: A total of 77 eyes of 40 patients of the original treatment group volunteered for a reexamination 10 years after surgery. The mean age of the patients was 45.9 years; 26 were women and 14 were men. UDVA was 0.09 ± 0.19 logMAR and CDVA was stable at -0.1 ± 0.09 logMAR. More than half of the eyes gained one or two Snellen lines, and none of the eyes lost two or more lines. Over the 10-year period, regression was 0.18 D. CONCLUSIONS: FLEx has stable results 10 years after treatment for myopia and astigmatism. [J Refract Surg. 2019;35(11):707-711.].


Assuntos
Córnea/patologia , Previsões , Miopia/cirurgia , Refração Ocular/fisiologia , Procedimentos Cirúrgicos Refrativos/métodos , Acuidade Visual , Adulto , Idoso , Córnea/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Miopia/diagnóstico , Miopia/fisiopatologia , Estudos Prospectivos , Microscopia com Lâmpada de Fenda , Resultado do Tratamento , Adulto Jovem
17.
J Refract Surg ; 35(10): 618-623, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610002

RESUMO

PURPOSE: To evaluate the 10-year results of refractive lenticule extraction using the small incision lenticule extraction (SMILE) technique for treatment of myopia and myopic astigmatism. METHODS: In 2008-2009, the first 91 eyes were treated using a novel surgical technique (SMILE), in which a refractive lenticule of intrastromal corneal tissue is removed through a small incision, completely eliminating flap cutting. A total of 56 of 91 eyes of the original treatment group volunteered for reexamination 10 years after surgery, including uncorrected and corrected distance visual acuity, objective and manifest refraction, and evaluation of the interface and corneal surface by slit-lamp examination. Late side effects such as corneal scarring, corneal ectasia, persistent dry eye symptoms, or cataract were documented. RESULTS: At 10 years postoperatively, there was no significant change from the 6-month results. Spherical equivalent was -0.35 ± 0.66 diopters and therefore close to target refraction. Sixteen of the 56 eyes (29%) had gained one to two Snellen lines. There was no loss of two or more lines in the long term. Regression was -0.35 ± 0.66 diopters over the 10-year period. CONCLUSIONS: This 10-year long-term study demonstrates SMILE to be an effective, stable, and safe procedure for the treatment of myopia and myopic astigmatism. [J Refract Surg. 2019;35(10):618-623.].


Assuntos
Astigmatismo/cirurgia , Substância Própria/cirurgia , Cirurgia da Córnea a Laser/métodos , Miopia/cirurgia , Adulto , Idoso , Astigmatismo/fisiopatologia , Paquimetria Corneana , Topografia da Córnea , Feminino , Seguimentos , Humanos , Masculino , Microcirurgia/métodos , Pessoa de Meia-Idade , Miopia/fisiopatologia , Estudos Prospectivos , Refração Ocular/fisiologia , Resultado do Tratamento , Acuidade Visual/fisiologia
18.
J Cataract Refract Surg ; 34(9): 1513-20, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18721712

RESUMO

PURPOSE: To prospectively study the feasibility of femtosecond lenticule extraction (FLE), a new method of refractive correction. SETTING: Department of Ophthalmology, Philipps University of Marburg and Helios Clinic, Erfurt, Germany. METHODS: A flap and a lenticule of intrastromal corneal tissue were simultaneously cut with a VisuMax femtosecond laser system. Next, the lenticule was manually removed and the flap repositioned. The target refraction in all cases was -0.75 diopter (D). RESULTS: All 10 myopic eyes in the initial treatment group completed the final 6-month follow-up. The mean patient age was 39 years. The mean spherical equivalent (SE) was -4.73 +/- 1.48 (SD) preoperatively and -0.33 +/- 0.61 D 6 months postoperatively. Ninety percent of eyes were within +/-1.00 D and 40% were within +/-0.50 D of the intended correction. No eye lost 2 or more Snellen lines. Corneal topography showed large, prolate optical zones. Aberrometry showed no significant induction of higher-order aberrations. On a standardized questionnaire, all patients said they were very satisfied with the results. CONCLUSIONS: Preliminary results indicate that FLEx [corrected] is a promising new corneal refractive procedure to correct myopia.


Assuntos
Substância Própria/cirurgia , Cirurgia da Córnea a Laser/métodos , Miopia/cirurgia , Retalhos Cirúrgicos , Adulto , Topografia da Córnea , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Pressão Intraocular , Lasers de Excimer/efeitos adversos , Lasers de Excimer/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários , Resultado do Tratamento , Acuidade Visual/fisiologia
20.
J Refract Surg ; 34(1): 6-10, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29315435

RESUMO

PURPOSE: To investigate new lenticule profiles for the treatment of hyperopia by femtosecond lenticule extraction (FLEx) for spherocylindrical hyperopia using a modified laser scan sequence. METHODS: In this prospective 9-month study, 39 eyes of 22 patients with the mean age of 49 years (range: 27 to 56 years) underwent hyperopic FLEx. The mean optical zone was 6 mm (range: 5.75 to 6.75 mm) with keratometry readings and magnitude of correction adjusted mean transition zone of 2.1 mm (range: 1.80 to 2.89 mm). The lenticule thickness was set at 25 µm in the center and 10 µm at the edge. RESULTS: Preoperative spherical equivalent manifest refraction was +1.96 ± 1.04 diopters (D) (range: +0.63 to +4.50 D). Because of the presbyopic age, the treatment was aimed at low myopia in 75% of the eyes treated. At the final 9-month follow-up visit, the mean spherical equivalent was -0.40 ± 0.61 D (range: -1.50 to +0.75 D), with 70% of eyes treated within ±0.50 D and 89% of eyes within ±1.00 D of intended correction. The regression was +0.29 D between 1 week and 6 months but 0.03 D between 6 and 9 months. A total of 10% of eyes lost one line of corrected distance visual acuity, respectively. There were no losses of two or more lines of visual acuity or any serious intraoperative or postoperative complications. CONCLUSIONS: Treatment of spherocylindrical hyperopia by FLEx led to refractive results similar to published outcomes on hyperopic femtosecond laser-assisted LASIK. [J Refract Surg. 2018;34(1):6-10.].


Assuntos
Substância Própria/cirurgia , Cirurgia da Córnea a Laser/métodos , Hiperopia/cirurgia , Adulto , Substância Própria/fisiopatologia , Topografia da Córnea , Feminino , Humanos , Hiperopia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Refração Ocular/fisiologia , Resultado do Tratamento , Acuidade Visual/fisiologia
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