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Human lens regeneration and the Bag-in-the-Lens (BIL) surgical treatment for cataract both depend upon lens capsule closure for their success. Our studies suggest that the first three days after surgery are critical to their long-term outcomes. Using a rat model of lens regeneration, we evidenced lens epithelial cell (LEC) proliferation increased some 50 fold in the first day before rapidly declining to rates observed in the germinative zone of the contra-lateral, un-operated lens. Cell multi-layering at the lens equator occurred on days 1 and 2, but then reorganised into two discrete layers by day 3. E- and N-cadherin expression preceded cell polarity being re-established during the first week. Aquaporin 0 (AQP0) was first detected in the elongated cells at the lens equator at day 7. Cells at the capsulotomy site, however, behaved very differently expressing the epithelial mesenchymal transition (EMT) markers fibronectin and alpha-smooth muscle actin (SMA) from day 3 onwards. The physical interaction between the apical surfaces of the anterior and posterior LECs from day 3 after surgery preceded cell elongation. In the human BIL sample fibre cell formation was confirmed by both histological and proteome analyses, but the cellular response is less ordered and variable culminating in Soemmerring's ring (SR) formation and sometimes Elschnig's pearls. This we evidence for lenses from a single patient. No bow region or recognisable epithelial-fibre cell interface (EFI) was evident and consequently the fibre cells were disorganised. We conclude that lens cells require spatial and cellular cues to initiate, sustain and produce an optically functional tissue in addition to capsule integrity and the EFI.
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Opacificação da Cápsula/metabolismo , Células Epiteliais/fisiologia , Implante de Lente Intraocular , Cristalino/fisiologia , Regeneração/fisiologia , Actinas/metabolismo , Idoso , Animais , Aquaporinas/metabolismo , Caderinas/metabolismo , Proliferação de Células/fisiologia , Células Epiteliais/ultraestrutura , Transição Epitelial-Mesenquimal/fisiologia , Proteínas do Olho/metabolismo , Feminino , Fibronectinas/metabolismo , Humanos , Marcação In Situ das Extremidades Cortadas , Cápsula do Cristalino/citologia , Cápsula do Cristalino/cirurgia , Cristalino/ultraestrutura , Masculino , Microscopia Eletrônica , Microscopia de Fluorescência , Modelos Animais , Proteínas do Tecido Nervoso/metabolismo , Proteômica , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em TandemRESUMO
INTRODUCTION: To assess the postoperative outcome and patient-reported satisfaction, spectacle independence, and dysphotopsia after implantation with the mutifocal Rayner Sulcoflex supplementary intraocular lens (sIOL). MATERIALS AND METHODS: We analyzed the outcome of all patients implanted with a multifocal sIOL between 2009 and 2011. In all cases, the sIOL was the Rayner Sulcoflex IOL (type 653F) and the primary IOL was a bag-in-the-lens (BIL) IOL. The data were obtained through a retrospective analysis of the patient records and by means of a questionnaire, 5 years after sIOL implantation. RESULTS: This study included 31 eyes of 20 patients. In 13 eyes, the sIOL needed explantation (n = 13, 41.94%). Dysphotopsia is a frequent complaint (12/15 patients: 80.0%) after sIOL implantation. In 13 out of 31 eyes (41.94%), pigment deposits were found on the sIOL with variable clinical complaints. Five eyes required additional surgery because of clinically significant deposits. DISCUSSION/CONCLUSION: Patients with a multifocal sIOL in combination with a BIL implantation have a higher incidence of dysphotopsia compared to previously published studies. Dysphotopsia was the main complaint and reason for explantation. We encountered a high incidence of pigmented IOL deposits. The sIOLs can be safely removed even years after implantation.
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Lentes Intraoculares , Lentes Intraoculares Multifocais , Seguimentos , Humanos , Implante de Lente Intraocular , Facoemulsificação , Estudos Retrospectivos , Resultado do Tratamento , Transtornos da Visão , Acuidade VisualRESUMO
BACKGROUND: Subluxation of the crystalline lens in childhood confronts the surgeon with a dilemma: to operate or to wait and see. Surgery is usually not performed when the subluxation is still limited. However, postponing the surgery increases the surgical difficulty as the capsular bag becomes more difficult to use as a means of support for the intraocular lens (IOL). A large number of children already present a pronounced subluxation at first presentation. In this paper, we describe a technique to optimise centration and fixation of the bag-in-the-lens (BIL) IOL in children younger than 7 years of age with congenital ectopia lentis. METHODS: Between October 2019 and December 2020, we performed lens extraction using a combination of bean-shaped segments to support the BIL IOL and a 6â-â0 polypropylene loop fixated at the sclera, following the Yamane technique, for the purpose of centration. We used this technique for seven eyes of four patients. The patients were between 2 and 6 years old; 3 boys and 1 girl. A definite diagnosis of Marfan syndrome was made for two children; for the other two, there was no proven underlying pathology. The luxation was upwards in all cases. The degree of luxation was severe in all eyes. The preoperative refraction values showed high astigmatism values for all eyes, ranging from 6.5 to 11.25 dioptres. Three out of the four patients were myopic, ranging from - 1.5 to - 9 dioptres. RESULTS: The surgery could be performed without major complications in all eyes. Good centration was obtained, which remained stable in the postoperative period. Refraction improved with greatly diminished degrees of astigmatism (ranging from 0.25 to 3 dioptres) and myopia (spheres ranging from - 2 to + 1.75 dioptres). CONCLUSION: Our novel technique incorporated the BIL technique with the addition of bean-shaped segments and a polypropylene 6/0 suture fixated at the sclera. In this way, we were able to obtain good centration and stability of the implanted IOL, as well as a good refractive outcome in all cases.
Assuntos
Ectopia do Cristalino , Lentes Intraoculares , Criança , Pré-Escolar , Ectopia do Cristalino/diagnóstico , Ectopia do Cristalino/cirurgia , Feminino , Humanos , Implante de Lente Intraocular , Masculino , Estudos Retrospectivos , Acuidade VisualRESUMO
BACKGROUND: Cataract surgery in diabetics is more technically challenging due to a number of factors including poor intraoperative pupil dilation and a higher risk of vision threatening complications. This study evaluates the safety and efficacy of an intracameral combination of 2 mydriatics and 1 anesthetic (ICMA, Mydrane) for cataract surgery in patients with well-controlled type-2 diabetes. METHODS: Post-hoc subgroup analysis of a phase 3 randomized study, comparing ICMA to a conventional topical regimen. Data were collected from 68 centers in Europe and Algeria. Only well-controlled type-2 diabetics, free of pre-proliferative retinopathy, were included. The results for non-diabetics are also reported. The primary efficacy variable was successful capsulorhexis without additional mydriatic treatment. Postoperative safety included adverse events, endothelial cell density and vision. RESULTS: Among 591 randomized patients, 57 (9.6%) had controlled type 2 diabetes [24 (42.1%) in the ICMA Group and 33 (57.9%) in the Topical Group; intention-to-treat (ITT) set]. Among diabetics, capsulorhexis was successfully performed without additional mydriatics in 24 (96.0%; modified-ITT set) patients in the ICMA Group and 26 (89.7%) in the Topical Group. These proportions were similar in non-diabetics. No diabetic patient [1 (0.5%) non-diabetics] in the ICMA Group had a significant decrease in pupil size (≥3 mm) intraoperatively compared to 4 (16.0%; modified-ITT set) diabetics [16 (7.3%) non-diabetics] in the Topical group. Ocular AE among diabetics occurred in 2 (8.0%; Safety set) patients in the ICMA Group and 5 (16.7%) in the Topical Group. Endothelial cell density at 1 month postoperatively was similar between groups in diabetics (P = 0.627) and non-diabetics (P = 0.368). CONCLUSIONS: ICMA is effective and can be safely used in patients with well-controlled diabetes, with potential advantages compared to a topical regimen including reduced systemic risk, better corneal integrity and reduced risk of ocular complications. TRIAL REGISTRATION: The trial was registered at (reference # NCT02101359) on April 2, 2014.
Assuntos
Catarata/complicações , Diabetes Mellitus Tipo 2/complicações , Implante de Lente Intraocular/métodos , Lidocaína/administração & dosagem , Midriáticos/administração & dosagem , Facoemulsificação/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestésicos Locais/administração & dosagem , Câmara Anterior , Quimioterapia Combinada , Feminino , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Soluções Oftálmicas , Estudos Prospectivos , Resultado do TratamentoRESUMO
Pterygium is a common eye disease, linked to an increased exposure to UV radiation and dry environments. The associated pathology culminates in visual impairment and, in some rare cases, blindness. However, there remains a lot of uncertainty concerning the pathogenesis of this fibrovascular lesion. As the composition of the tear film provides a reflection into the pathological changes at the ocular surface, tear analysis represents an ideal approach to gain insight in the progression of disease following pterygiectomy. This study enrolled 19 patients and age/gender-matched healthy controls. Tear film levels of interleukin- (IL-) 6, IL-8, and vascular endothelial growth factor (VEGF) were investigated over time, and preoperative concentrations were linked to corneal neovascularization and pterygium size. Diminished tear film levels were found in unilateral patients who show no clinical signs of pterygium recurrence over a period of one year. Hence, our results highlight the potential of using the course of IL-6, IL-8, and VEGF levels in tears as biomarkers for recovery. In addition, when focusing on the affected eyes (i.e., primary and recurrent pterygium), we detected fold changes in preoperative cytokine concentrations to correspond with disease severity. As our proposed biomarkers did not reveal a linear relationship with corneal neovascularization nor the invasive behaviour of pterygium, no exact role in the pterygium pathology could be established. Hence, our data point to these factors being contributors rather than decisive players in the pathological processes.
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Citocinas/metabolismo , Pterígio/patologia , Lágrimas/química , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Pterígio/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
PURPOSE: To study the corneal and internal astigmatism and the age-related changes underlying the known refractive shift with-the-rule (WTR) towards against-the-rule (ATR) astigmatism. METHODS: Refractive and corneal biometry data were collected for a total of 1195 healthy Caucasian subjects, recruited by ophthalmological centres across Europe. After conversion of refractive and corneal surface astigmatism to power vectors J0 and J45 , the total corneal and internal astigmatism were calculated. RESULTS: Both refractive power vectors had leptokurtic distributions with a narrow peak at zero, and a broader, secondary distribution at its base, corresponding to eyes without balanced components. This may be fitted with a bigaussian function (J0 : r² = 0.87; J45 : r² = 0.98). Statistically significant changes in these distributions are seen with age: for refractive J0 the narrow peak shortens progressively, while the broad peak shifts positive from to negative values, corresponding to increased astigmatism and a shift from with-the-rule towards against-the-rule. For J45 the narrow peak shortens with age as well, while the broad peak flattens. These changes in refractive J0 result from statistically significant negative shifts in both the corneal and internal components with age (Kruskal-Wallis, p < 0.05). CONCLUSION: In young participants corneal and internal astigmatism partially cancel each other out. This balance between both is gradually lost after age 50, leading to larger amounts of refractive astigmatism, as well as a reorientation of the axis. Given the small amplitude of these changes, they are unlikely to have repercussions for long term stability toric cataract or refractive surgery outcomes.
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Envelhecimento/fisiologia , Astigmatismo/fisiopatologia , Córnea/fisiopatologia , Adulto , Fatores Etários , Idoso , Topografia da Córnea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Refração Ocular/fisiologia , Adulto JovemRESUMO
PURPOSE: To present and validate a stochastic eye model for developing keratoconus to e.g. improve optical corrective strategies. This could be particularly useful for researchers that do not have access to original keratoconic data. METHODS: The Scheimpflug tomography, ocular biometry and wavefront of 145 keratoconic right eyes were collected. These data were processed using principal component analysis for parameter reduction, followed by a multivariate Gaussian fit that produces a stochastic model for keratoconus (SyntEyes KTC). The output of this model is filtered to remove the occasional incorrect topography patterns by either an automatic or manual procedure. Finally, the output of this keratoconus model is matched to that of the original model for normal eyes using the non-corneal biometry to obtain a description of keratoconus development. RESULTS: The synthetic data generated by the model were found to be significantly equal to the original data (non-parametric Mann-Whitney equivalence test; 145/154 passed). The variability of the synthetic data, however, was often significantly less than that of the original data, especially for the higher order Zernike terms of corneal elevation (non-parametric Levene test; p < 0.05/154). These results remained generally the same after applying either filter procedure to remove the synthetic eyes with incorrect topographies. Interpolation between matched pairs of normal and keratoconic SyntEyes appears to provide an adequate model for keratoconus progression. CONCLUSION: The synthetic data provided by the proposed keratoconus model closely resembles actual clinical data and may be used for a range of research applications when (sufficient) real data is not available.
Assuntos
Córnea/patologia , Ceratocone/diagnóstico , Modelos Estatísticos , Refração Ocular/fisiologia , Adolescente , Adulto , Topografia da Córnea/métodos , Feminino , Humanos , Ceratocone/fisiopatologia , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND: The presence of a space between the posterior capsule and the anterior vitreous was first reported in 1887, but difficulties inherent in examining this structure made it impossible to visualize this area in vivo until now. Estimation of the size of this space was considered to be impossible. MATERIALS AND METHODS: We utilized an optical coherence tomography (OCT) system attached to the Zeiss Opmi Lumera 700/Rescan microscope (Zeiss Ltd., Jena, Germany) to provide real-time images of the Berger space, the anterior hyaloid and the ligament of Wieger. RESULTS: Imaging in 3 patients provided beautiful, real-time OCT images of the Berger space and of the ligament of Wieger. In one highly myopic eye, there was even evidence of anterior vitreous detachment. CONCLUSION: Previously unseen transparent structures of the eye can now be imaged intraoperatively using real-time OCT. This new technology seems very promising in achieving a better understanding of the anterior vitreous interface, more specifically of the anterior hyaloid and its posterior capsule attachment by the ligament of Wieger. Changes in the anterior hyaloid and its capsular attachment may contribute to a better understanding of the posterior segment complications after cataract surgery.
Assuntos
Capsulorrexe/métodos , Cirurgia Assistida por Computador/métodos , Tomografia de Coerência Óptica/métodos , Corpo Vítreo/patologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
PURPOSE: To determine the repeatability of a color LED corneal topographer (Cassini; iOptics, The Hague, The Netherlands) and compare it with Placido and Scheimpflug based devices (EyeSys 2000; EyeSys Laboratories, Houston, TX, and Pentacam HR; Oculus Optikgeräte GmbH, Wetzlar, Germany). METHODS: This prospective study involved 20 healthy volunteers (20 eyes) recruited from the staff of the Antwerp University Hospital. For each eye, three measurements were taken using each device, from which eight parameters describing keratometry and astigmatism were derived. Repeatability was assessed using intrasession, within-subject analysis of variance. Agreement was evaluated between pairs of devices with Bland- Altman plots and 95% confidence intervals. RESULTS: The repeatability values were good for all three devices, although slightly worse for the Cassini than for the other two devices for steep, flat, and mean keratometry. The EyeSys showed worse repeatability for the astigmatism axis. EyeSys and Pentacam agreed well with each other in terms of mean keratometry, whereas the Cassini gave consistently higher values by 0.52 diopters (D) when compared with the EyeSys (P < .05, paired t test) and by 0.38 D when compared with the Pentacam (P < .05, paired t test). The Cassini provided similar repeatability values (2.31°) for the astigmatism axis to the Pentacam (2.22°), in contrast to the EyeSys, which produced much more variable axes (9.0°) (P < .05, paired t test). CONCLUSIONS: Overall, the three devices display comparable repeatability. The one exception is the astigmatism axis measurement of the EyeSys. The Cassini provides higher keratometry values than the other two devices, but the astigmatism axis agrees well with that provided by the Pentacam.
Assuntos
Córnea/anatomia & histologia , Topografia da Córnea/instrumentação , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
BACKGROUND: To determine if a standardized, non-xenogenic, reduced manipulation cultivation and surgical transplantation of limbal stem cell grafts is a safe and effective treatment option for patients with total and partial limbal stem cell deficiency. METHODS: In vitro cellular outgrowth and phenotype of the limbal epithelial cell and composite grafts were validated using a new protocol. Patients received either autologous (n = 15) or allogenic (n = 3) explants cultured using a standardized protocol free from xenogenic products. The resulting grafts were transplanted using a reduced manipulation surgical technique. RESULTS: The majority of cells (>50%) displayed a progenitor phenotype typified by positive immunofluorescence for ∆Np63, CK14 and ABCG2 and low immunofluorescence for CK3/12 and desmoglein 3 proteins. The surgical protocol was designed to minimize manipulation and the graft itself was secured without sutures. The transplant recipients were followed for a mean of 24 months. Twelve of the 18 transplant recipients were graded as anatomically successful (67%), based on the defined success parameters. There was a significant reduction in corneal neovascularization, which was accompanied by an improvement in pain though not photophobia or central corneal opacity post transplant. The transplantation protocol showed no measureable effect on visual acuity. CONCLUSION: We conclude that this standardized culture system and surgical approach is safe and effective in reducing corneal neovascularization. The technique is free from animal contaminants and maintains a large proportion of progenitor cells. Although this technique did not improve visual function, restoring a functional epithelial cell layer and reducing corneal neovascularization provides an improved platform for a penetrating keratoplasty to ultimately improve visual function.
Assuntos
Limbo da Córnea/citologia , Transplante de Células-Tronco , Células-Tronco/citologia , Adolescente , Adulto , Idoso , Âmnio/citologia , Animais , Proliferação de Células , Células Cultivadas , Criança , Doenças da Córnea/fisiopatologia , Doenças da Córnea/cirurgia , Doenças da Córnea/terapia , Células Epiteliais/citologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Cuidados Pré-Operatórios , Reprodutibilidade dos Testes , Transplante Heterólogo , Resultado do Tratamento , Acuidade Visual , Adulto JovemRESUMO
PURPOSE: To study how the leptokurtic shape of the refractive distribution can be derived from ocular biometry by means of a multivariate Gaussian model. METHODS: Autorefraction and optical biometry data (Scheimpflug and partial coherence interferometry) were obtained for 1136 right eyes of healthy white subjects recruited by various European ophthalmological centers participating in Project Gullstrand. These biometric data were fitted with linear combinations of multivariate Gaussians to create a Monte Carlo simulation of the biometry, from which the corresponding refraction was calculated. These simulated data were then compared with the original data by histogram analysis. RESULTS: The distribution of the ocular refraction more closely resembled a bigaussian than a single Gaussian function (F test, p < 0.001). This also applied to the axial length, which caused the combined biometry data to be better represented by a linear combination of two multivariate Gaussians rather than by a single one (F test, p < 0.001). Corneal curvature, anterior chamber depth, and lens power, on the other hand, displayed a normal distribution. All distributions were found to gradually change with age. The statistical descriptors of these two subgroups were compared and found to differ significantly in average and SD for the refraction, axial length, and anterior chamber depth. All distributions were also found to change significantly with age. CONCLUSIONS: The bigaussian model provides a more accurate description of the data from the original refractive distribution and suggests that the general population may be composed of two separate subgroups with different biometric properties.
Assuntos
Biometria , Hiperopia/fisiopatologia , Miopia/fisiopatologia , Distribuição Normal , Refração Ocular/fisiologia , Adulto , Idoso , Envelhecimento/fisiologia , Câmara Anterior/anatomia & histologia , Comprimento Axial do Olho/fisiopatologia , Córnea/anatomia & histologia , Feminino , Humanos , Interferometria , Cristalino/fisiologia , Masculino , Pessoa de Meia-Idade , Método de Monte Carlo , Adulto JovemRESUMO
This research uses mathematical modelling to evaluate the influence of the ligament of Wieger on the crystalline lens shape at rest, and during accommodation. An axisymmetric model of the anterior segment, including the ligament of Wieger, was created using the finite element method. Different conditions including variations of stiffness and positions of the ligament, with and without the ligament, were tested to see how they affected lens curvature and optical power. Adding the ligament of Wieger to the simulation had a noticeable impact on the optical power of the lens, particularly on the posterior surface power and total power. Ligament stiffness and width significant influenced the accommodative range of the eye by - 0.95D and - 2.39D for ligaments with the same and 3× the stiffness of the capsular bag, respectively. Ligament width and inner diameter had negligible effects on lens thickness but did have significant effects on posterior surface power and accommodation. In this simulation, we found that the ligament of Wieger can significantly affect the lens shape, both at rest and during accommodation, and may need to be considered in lens models.
RESUMO
PURPOSE: To assess the changes of the surfaces and optical properties of the cornea as a function of age. METHODS: The corneal shape of 407 normal eyes of 211 subjects with ages ranging from 4 to 79 years old was determined by means of Scheimpflug imaging. These data were analyzed by fitting their elevation topographies to a general surface model, which consists of a biconic plus a Zernike polynomial expansion. The analysis includes the computation of the position and orientation of the model in the three-dimensional space to determine the orientation of the optical axis and the apex coordinates. RESULTS: Both average corneal surfaces show negative conic constant plus higher order aspheric terms Z(0)(4) and Z(0)(6) are significant). These surfaces are misaligned between them and with the line of sight. Such misalignment increases with age as the cornea seems to rotate as a solid body. The apex curvature and the magnitude of the conic constant along the most curved meridian increase as well, but the largest change with age correspond to the aspheric terms Z(0)(4) and Z(0)(6). As a result, the spherical aberration (SA) of the average cornea increases with age at a rate similar to the total SA of the eye. CONCLUSIONS: The average corneal surfaces are misaligned general aspheres. Corneal SA is higher than total SA, but both SAs increase with age at a similar rate. This confirms that the lens is partially compensating SA and that such compensation is preserved with aging. Misalignment and solid body rotation seem to reduce astigmatism and coma for young and middle-aged corneas.
Assuntos
Envelhecimento/fisiologia , Córnea/fisiologia , Refração Ocular/fisiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Córnea/anatomia & histologia , Topografia da Córnea/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
PURPOSE: To reconstruct and correct four historical biometry data sets. METHODS: The data sets measured by Stenström (1946), Sorsby (1957), Zeeman (1911), and Awerbach (1900) are of great historical interest but have issues that need to be dealt with before they may be of practical use in comparative studies. These issues range from only publishing statistical descriptors instead of the numerical data (Stenström) to assuming an equivalent refractive index of the crystalline lens that was constant with age (Sorsby) and calculation errors (Awerbach and Zeeman). These issues were corrected by only considering subjects with ages ranging between 20 and 35 years and refraction within ±8D. This left 86 eyes for Sorsby, 73 for Zeeman, and 54 for Awerbach that could be used for further study. For the Stenström data set, the statistical descriptors of 983 eyes were used to generate data that are statistically indistinguishable from the original data through multivariate Gaussian modeling. RESULTS: After verification that all biometric parameters, except refraction, could be well approximated by a Gaussian distribution, a statistical eye model was defined for the Stenström data set. By means of the "two-one-sided t test" procedure, it was demonstrated that the data generated by the model are statistically indistinguishable from the original data at a confidence level of 99%. CONCLUSIONS: These results provide the best possible correction and reconstruction of the historical data sets. Provided one acknowledges the limitations of the data acquisition at the time, these data may be of use in studies on how ocular biometry has changed in the past century.
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Biometria/métodos , Miopia/epidemiologia , Adulto , Feminino , Humanos , Masculino , Matemática , Modelos Estatísticos , Distribuição Normal , Refração Ocular/fisiologia , Retinoscopia , População Branca , Adulto JovemRESUMO
PURPOSE: The purpose of this study was to assess the orientation of the anterior and posterior corneal surfaces with respect to the keratometric axis in the three-dimensional space. METHODS: A group of 407 normal corneas of 211 subjects with ages ranging from 4 to 79 years was analyzed by fitting their elevation topographies to a general three-axes ellipsoid model. RESULTS: The resulting average tilt (-1.20 degrees) and tip (1.83 degrees) of the anterior surface are consistent with previous findings. In addition, we found that the posterior surface is also misaligned with the anterior by a similar amount. The cornea seems to rotate as a solid body by 2 minutes of arc per year. CONCLUSIONS: The misalignment between the cornea and the keratometric axis increases as a function of age. This tiny, but significant (p < 0.005), rotation may have an important impact on optical quality because it could cause an important increase of the higher order aberrations of the cornea with age.
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Envelhecimento , Córnea/anatomia & histologia , Topografia da Córnea/métodos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Adulto JovemRESUMO
PURPOSE: The common change in corneal morphology that is seen in keratoconus (KC) suggests the presence of common high-order aberration (HOA) structures and the potential for HOA corrections that apply to more than one eye. The purpose of this investigation is to classify a sample of KC eyes into subgroups based on similar HOA characteristics and simulate optical performance of common HOA corrections on members of each subgroup. METHODS: High-order aberrations were recorded over a 5-mm pupil on 111 KC eyes. The eyes were divided into five subgroups based on observed commonality in HOA structure. From each subgroup, two eyes were removed for later evaluation of corrections. Principal components analysis was performed on the remaining eyes of each subgroup. The first principal component was scaled to form a set of corrections. Simulated optical correction of the test eyes was performed by identifying the magnitude of the inner-group correction providing the lowest level of residual higher order root mean square wavefront error (HORMS). Residual uncorrected HORMS was compared with levels found in uncorrected normal eyes and KC eyes wearing rigid gas-permeable corrections. RESULTS: Ninety (81%) of the 111 eyes were included in one of the five subgroups. All 10 test eyes experienced a reduction in HORMS with a template correction compared with their uncorrected levels. Median HORMS reduced from uncorrected levels of 2.14 to 0.97 µm. On average, the 10 subjects experienced a 51% reduction in HORMS (minimum, 16%; maximum, 81%; p < 0.01). When scaled to a 4-mm pupil, five of the 10 eyes experienced residual uncorrected HORMS within limits associated with gas-permeable wear. CONCLUSIONS: Overlap exists across these templates because of the dominance of vertical coma in the HOA structure. All eyes evaluated received reduced HORMS with a template-based correction.
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Lentes de Contato , Córnea/patologia , Ceratocone/terapia , Refração Ocular/fisiologia , Erros de Refração/terapia , Córnea/fisiopatologia , Topografia da Córnea , Seguimentos , Humanos , Ceratocone/complicações , Ceratocone/diagnóstico , Desenho de Prótese , Erros de Refração/etiologia , Erros de Refração/fisiopatologia , Resultado do TratamentoRESUMO
Cataract is a common condition observed in patients with diabetes mellitus frequently requiring surgical intervention. The bag-in-the-lens (BIL) intraocular implant is an alternative approach to standard lens-in-the-bag cataract surgery. The lens is supported by anterior and posterior capsulorhexes, which confers a number of advantages in terms of lens centration, rotational stability and prevention of posterior capsular opacity. The purpose of this report is to describe the results of BIL cataract surgery in a retrospective cohort of diabetic patients. Fifty-four cases of BIL surgery are included with a follow-up period of 1 year. Visual acuity outcomes were comparable to previously published standard lens-in-the-bag procedures. There were no reports of posterior capsular opacification and the grade of diabetic retinopathy remained stable. Three cases of clinically significant macular edema were detected over the follow-up period. We conclude that the BIL implantation technique is an advantageous approach to treating cataract in the diabetic population.
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Capsulorrexe/métodos , Catarata/etiologia , Complicações do Diabetes/complicações , Implante de Lente Intraocular/métodos , Lentes Intraoculares , Idoso , Complicações do Diabetes/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Desenho de Prótese , Estudos Retrospectivos , Acuidade VisualRESUMO
BACKGROUND: Susac syndrome consists of the triad of encephalopathy, branch retinal artery occlusion, and hearing loss and is believed to be an immune-mediated endotheliopathy. Arteriolar wall hyperfluorescence (AWH) on retinal fluorescein angiography (FA) has been described in the literature as a classic ophthalmic sign for Susac syndrome. In this article, we report a pattern of distally shifting segments of AWH on FA over time that was observed in two cases. METHODS: Two cases of Susac syndrome are presented with an emphasis on FA findings, obtained at frequent intervals during follow-up. RESULTS: In both cases, FA displays a shifting pattern of segments of AWH distal to the localization of the AWH observed on the previous FA. CONCLUSION: In patients with Susac syndrome, FA plays an important role in aiding diagnosis and monitoring the efficacy of treatment and disease activity during follow-up. In these two cases, the angiography revealed how the AWH can migrate along the vessel over time. This is the first published report showing an evolving distally shifting pattern of AWH in patients with Susac syndrome.
Assuntos
Oclusão da Artéria Retiniana , Síndrome de Susac , Humanos , Síndrome de Susac/diagnóstico , Angiofluoresceinografia , Oclusão da Artéria Retiniana/diagnóstico , Imageamento por Ressonância MagnéticaRESUMO
PURPOSE: To determine the incidence of clinically significant pseudophakic cystoid macular edema (CSPME) after phacoemulsification using the 'bag-in-the-lens' lens (BIL) implantation technique and to examine the influence of associated risk factors for clinically significant pseudophakic macular edema (CSPME), both ocular and systemic. METHODS: This retrospective study included 2419 first-operated eyes of 2419 adults who underwent phacoemulsification cataract surgery using the BIL implantation technique between January 2013 and December 2018 in the Antwerp University Hospital, Belgium. The significance of several risk factors (age, gender, previous history, intra- and postoperative complications) was examined by extraction of electronic medical files. RESULTS: The 3-month incidence of CSPME in the subgroup without risk factors was 0.00% (95% CI: 0.00 -NA). The 3-month incidence of CSPME in the subgroup with risk factors was 0.57% (95% CI 0.22-1.29%). The 3-month incidence of CSPME in the total population of 2419 patients was 0.29% (95% CI: 0.11-0.65%). The risk factors most significantly associated with CSPME included renal insufficiency (hazard ration [HR]: 5.42; 95% CI: 1.69-17.44; P = .014), exudative age-related macular degeneration (HR: 74.50, 95% CI: 25.75-215.6; P < .001) and retinal vein occlusion (HR: 22.48, 95% CI: 4.55-111.02; P = .005). CONCLUSIONS: In the absence of risk factors, the incidence of CSPME was zero. We can conclude that Primary Posterior Continuous Curvilinear Capsulorhexis (PPCCC) does not increase the risk for CSPME. Non-inferiority of the BIL implantation regarding the development of CSPME, relative to the traditional 'lens-in-the-bag' (LIB) implantation, confirms that BIL is a safe surgical technique. This study also illustrates a previously undescribed risk factor for developing CSPME, namely renal insufficiency.