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1.
Exp Eye Res ; 207: 108578, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33864786

RESUMO

OBJECTIVE: To compare the biometric parameters provided by A-scan ultrasonography and the Lenstar optical biometer in guinea pig eyes, including anterior segment depth (ASD), lens thickness (LT), vitreous chamber depth (VCD), and axial length (AL), and differences of them between treated form deprivation (FD) eyes and untreated fellow eyes after 4 weeks of FD. METHODS: Three-week-old guinea pigs (N = 41) were subjected to biometric measurements before monocular FD (baseline) and after a 4-week FD. Statistical analyses including within-subject standard deviation (SDwithin), coefficient of variation (CV), and intraclass correlation coefficient (ICC), used to evaluate repeatability for both the A-scan ultrasonography and the Lenstar individually, and correlation and Bland-Altman analyses were used to assess agreement between the two methods. The absolute values of ASD, LT, VCD and AL as measured by the two devices were compared, and the differences of them between treated (T) and untreated fellow (F) eyes (ΔASD, ΔLT, ΔVCD and ΔAL) (Δ = T-F) were compared between the two devices after 4 weeks of FD. RESULTS: Measurements by the Lenstar (ICC: 0.923-0.994) were more repeatable than A-scan ultrasonography (ICC: 0.825-0.870). There was a high correlation for AL (r = 0.851, P < 0.001), a moderate correlation for VCD (r = 0.571, P < 0.001) and LT (r = 0.423, P < 0.001), and a low correlation for ASD (r = 0.230, P < 0.01) between the two devices. The values for ASD, VCD and AL measured by A-scan ultrasonography were larger than those measured by the Lenstar (all, P < 0.001), while LT provided by A-scan ultrasonography was much smaller than that of the Lenstar (P < 0.001). Bland-Altman plots showed poor agreement of absolute values of the four parameters between the two devices. Moreover, there was a high correlation between both methods for ΔAL (r = 0.704, P < 0.001), a moderate correlation for ΔVCD (r = 0.534, P < 0.001) and ΔASD (r = 0.574, P < 0.001), and no correlation for ΔLT (r = 0.303, P = 0.054). The ΔASD, ΔLT, and ΔAL measurements obtained by A-scan ultrasonography were greater than those obtained by the Lenstar (all, P < 0.001), while ΔVCD was mildly smaller using A-scan ultrasonography (P < 0.05). Bland-Altman plots illustrated there is good agreement of ΔAL, ΔVCD, ΔASD, and ΔLT between the two devices. CONCLUSIONS: The Lenstar exhibited better repeatability and provided smaller measurements for AL, VCD and ASD than A-scan ultrasonography. Furthermore, a high correlation and a good agreement for the ΔAL was observed between the two devices after a period of FD. In summary, the two devices cannot replace each other directly to obtain absolute values of ASD, LT, VCD and AL, but the Lenstar still can serve as an option in measuring ΔAL between eyes in guinea pig myopia model.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Comprimento Axial do Olho/anatomia & histologia , Biometria/instrumentação , Interferometria/métodos , Cristalino/anatomia & histologia , Ultrassonografia/métodos , Corpo Vítreo/anatomia & histologia , Animais , Cobaias , Luz , Masculino , Reprodutibilidade dos Testes
2.
Exp Eye Res ; 203: 108394, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33310058

RESUMO

Micro-CT visualization allows reconstruction of eye structures with the resolution of light microscopy and estimation of tissue densities. Moreover, this method excludes damaging procedures and allows further histological staining due to the similar steps in the beginning. We have shown the feasibility of the lab-based micro-CT machine usage for visualization of clinically important compartments of human eye such as trabecular outflow pathway, retina, iris and ciliary body after pre-treatment with iodine in ethanol. We also identified the challenges of applying this contrasting technique to lens, cornea, and retina and proposed alternative staining methods for these tissues. Thereby this work provides a starting point for other studies for imaging of human eyes in normal and pathological conditions using lab-based micro-CT systems.


Assuntos
Enucleação Ocular , Olho/anatomia & histologia , Olho/diagnóstico por imagem , Microtomografia por Raio-X , Câmara Anterior/anatomia & histologia , Câmara Anterior/diagnóstico por imagem , Segmento Anterior do Olho/anatomia & histologia , Segmento Anterior do Olho/diagnóstico por imagem , Estudos de Viabilidade , Humanos , Imageamento Tridimensional , Cristalino/anatomia & histologia , Cristalino/diagnóstico por imagem , Retina/anatomia & histologia , Retina/diagnóstico por imagem
3.
Medicine (Baltimore) ; 99(7): e19187, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32049854

RESUMO

We aimed to observe the opening status and morphological parameters of Schlemm's canal (SC) in normal eyes using enhanced depth imaging optical coherence tomography (EDI-OCT).Consecutive EDI-OCT scans were used to examine the right eye of 20 normal individuals. EDI-OCT was performed clockwise for 8 regions (at the 12:00, 1:30, 3:00, 4:30, 6:00, 7:30, 9:00 and 10:30 o'clock positions). Image processing and analysis in java software was used to measure the area, perimeter, and diameter of SC. Twenty-one serial scans of each region were evaluated and a total of 168 images were included in the analyses of each eye.The SC was detected in 100.0% of the sections. The distribution of individual measurements of SC was highly variable. The mean values of SC size significantly differed among the different clock-face positions. The mean values of the area, perimeter, and diameter of SC in the 9:00 o'clock position were the lowest, and those at the 7:30 o'clock position were the highest (P < .05). There was no obvious association between intraocular pressure and SC size at any clock position.Although SC tends to open circumferentially in normal individuals, the distribution of individual measurements is highly variable. Morphological manifestation of SC measured by EDI-OCT is a useful way to evaluate the circumferential opening status of SC.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Adulto , Segmento Anterior do Olho/diagnóstico por imagem , Feminino , Voluntários Saudáveis , Humanos , Masculino , Valores de Referência , Tomografia de Coerência Óptica , Adulto Jovem
4.
J Morphol ; 281(2): 240-249, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31876020

RESUMO

To investigate whether the thickness of the cornea in snakes correlates with overall anatomy, habitat or daily activity pattern, we measured corneal thickness using optical coherence tomography scanning in 44 species from 14 families (214 specimens) in the collection at the Natural History Museum (Denmark). Specifically, we analyzed whether the thickness of the cornea varies among species in absolute terms and relative to morphometrics, such as body length, spectacle diameter, and spectacle thickness. Furthermore, we examined whether corneal thickness reflects adaptation to different habitats and/or daily activity patterns. The snakes were defined as arboreal (n = 8), terrestrial (n = 22), fossorial (n = 7), and aquatic (n = 7); 14 species were classified as diurnal and 30 as nocturnal. We reveal that the interspecific variation in corneal thickness is largely explained by differences in body size, but find a tendency towards thicker corneas in diurnal (313 ± 227 µm) compared to nocturnal species (205 ± 169 µm). Furthermore, arboreal snakes had the thickest corneas and fossorial snakes the thinnest. Our study shows that body length, habitat, and daily activity pattern could explain the interspecific variation in corneal morphology among snakes. This study provides a quantitative analysis of the evolution of the corneal morphology in snakes, and it presents baseline values of corneal thickness of multiple snake species. We speculate that the cornea likely plays a role in snake vision, despite the fact that results from previous studies suggest that the cornea in snakes is not relevant for vision (Sivak, Vision Research, 1977, 17, 293-298).


Assuntos
Evolução Biológica , Córnea/anatomia & histologia , Serpentes/anatomia & histologia , Animais , Segmento Anterior do Olho/anatomia & histologia , Segmento Anterior do Olho/diagnóstico por imagem , Tamanho Corporal , Ritmo Circadiano/fisiologia , Córnea/diagnóstico por imagem , Ecossistema , Serpentes/fisiologia , Tomografia de Coerência Óptica
6.
J Cataract Refract Surg ; 45(9): 1294-1304, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31371153

RESUMO

PURPOSE: To investigate the predictive value of the intracrystalline interphase point (ICIP) measured with optical low-coherence reflectometry (OCLR) to estimate the final lens position (FLP) of an intraocular lens (IOL) after cataract surgery. SETTING: Alcañiz Hospital, Teruel, Spain. DESIGN: Single-center retrospective descriptive study. METHODS: Patients undergoing cataract surgery were enrolled. They were grouped according to the IOL implanted as follows: Group 1, Acrysof IQ aspheric SN60WF IOL (77 eyes); Group 2, enVista MX60 IOL (71 eyes); Group 3, CT Asphina 409 IOL (44 eyes). An OCLR-based biometer (Lenstar LS 900 system) was used for biometric measurements preoperatively and at 4 to 5 weeks postoperatively. RESULTS: The study comprised 192 eyes of 174 patients (mean age: 76.4 years). One hundred seventy eyes (88.5%) eyes showed an absolute refractive prediction error (ARPE) less than 0.50 diopters (D). The mean ARPE was 0.25 D ± 0.21 (SD). Significantly higher FLP values were found in Group 2 compared with the other two groups (P < .001). Significantly lower ICIP values were found in the eyes with an ARPE of 0.50 D or more compared with eyes that had an ARPE less than 0.50 D in Group 1 (P = .042) and Group 2 (P = .023). The correlation of the FLP with the ICIP was good in all three groups (r ≥ 0.74, P <.001). Three linear expressions were obtained to predict the FLP from the ICIP and other preoperative data (R2: 0.85, 0.69, and 0.49 in Groups 1, 2, and 3, respectively). CONCLUSIONS: The position of the ICIP measured with OCLR correlated with the FLP after cataract surgery, and it can be used to optimize IOL power calculations.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Biometria/instrumentação , Diagnóstico por Imagem/métodos , Implante de Lente Intraocular , Lentes Intraoculares , Facoemulsificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Marcadores Fiduciais , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Pseudofacia/fisiopatologia , Refração Ocular/fisiologia , Estudos Retrospectivos , Acuidade Visual/fisiologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-30994110

RESUMO

Pars plana vitrectomy is currently the most common technique used in retinal surgery. Although primarily involving the posterior segment of the eye it also affects the anterior segment. As this is a less published topic, the aim of this paper was to review the literature on changes in the anterior segment after uncomplicated pars plana vitrectomy using data based literature search. The conclusions are that even in otherwise ophthalmologically healthy patients, complications may occur in the anterior segment. Surgeons need to pay utmost attention in glaucoma patients and in those with endothelial insufficiency who are at highest risk of complications. He/she must also correctly plan a potential cataract surgery if not already done earlier. From the literature, most of the changes in the anterior segment after uncomplicated PPV are found to be temporary.


Assuntos
Segmento Anterior do Olho/fisiologia , Vitrectomia/métodos , Segmento Anterior do Olho/anatomia & histologia , Extração de Catarata/métodos , Córnea/anatomia & histologia , Epitélio Corneano/citologia , Humanos , Pressão Intraocular/fisiologia , Cristalino/fisiologia
8.
Vet Ophthalmol ; 22(3): 381-384, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30838772

RESUMO

OBJECTIVE: The purpose of this study is to measure parameters of the anterior segment of normal feline eyes using a rotating Scheimpflug camera in young and adult cats. PROCEDURE: Sixteen domestic short-haired (DSH) healthy cats (seven castrated males and nine spayed females) with a mean age of 17 months (SD = 3.5) were anesthetized. Cats were considered immature and adults if they were < or ≥12 months of age, respectively. The keratometric values, the anterior chamber depth (ACD), and central corneal thickness (CCT) of the right eye of each animal were measured using a Pentacam Oculus topographer. The repeatability of the measures was assessed by calculating the coefficient of variation of the successive measures in cats (five repetitions per cat). We performed an ANOVA to test the effect of age on the parameters measures. RESULTS: The mean CCT and ACD were 601.97 ± 38 µm and 5.27 ± 0.04 mm, respectively. No significant differences were observed between adult and young cat's measures. The average keratometric value was 39.6 ± 0.3 D. The mean average cylindrical error was 2.48 ± 0.35 D (43.75% "against-the-rule" astigmatism and 43.75% "oblique" astigmatism). CONCLUSION: The Oculus Pentacam under clinical conditions give CCT and ACD values very similar to those reported in previous studies. Corneal astigmatism measures were markedly elevated (>2 D). Further studies with a larger population of cats of various breeds and ages are needed to confirm or refute these results, using a rotating Scheimpflug camera.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Gatos/anatomia & histologia , Animais , Segmento Anterior do Olho/diagnóstico por imagem , Paquimetria Corneana/veterinária , Feminino , Masculino , Fotografação/veterinária , Valores de Referência
9.
Arq. bras. oftalmol ; 82(2): 129-135, Mar.-Apr. 2019. graf
Artigo em Inglês | LILACS | ID: biblio-989398

RESUMO

ABSTRACT Purpose: To determine the reliability of swept- source optical coherence tomography in cases in which soft contact lenses cannot be removed when acquiring biometric measurements. Methods: Eight subjects were included and only one eye per participant was analyzed. Each eye was measured six times by swept-source optical coherence tomography with the IOLMaster 700 instrument (Carl Zeiss Meditec, Jena, Germany). Axial length, central corneal thickness, anterior chamber depth, lens thickness, and keratometric measurements were evaluated for the naked eye and while wearing soft contact lenses of three different powers (-1.5, -3.0, and +2.0 D). Results: There were statistically significant changes in axial length, central corneal thickness, anterior chamber depth, and keratometric measurements with soft contact lenses as compared to the naked eye (p<0.001). However, there were no significant differences in lens thickness outcomes between the naked eye and while wearing the three soft contact lenses (p>0.5). The changes in axial length, central corneal thickness, and anterior chamber depth were lens-specific and dependent on the thickness of the lens used. Conclusions: Sept-source optical coherence tomography based lens thickness measurements while wearing soft contact lenses are comparable to those of the naked eye. However, the thickness and the optical design of the soft contact lens may lead to significant differences in the axial lengh, central corneal thickness, anterior chamber deph, and keratometric measurements.


RESUMO Objetivo: Determinar a confiabilidade da tomografia de coerência óptica de varredura em casos especiais em que lentes de contato gelatinosas não podem ser removidas ao realizar medições biométricas. Métodos: Oito indivíduos foram incluídos e apenas um olho por participante foi analisado. Cada olho foi medido seis vezes por tomografia de coerência óptica de varredura com o instrumento IOLMaster 700 (Carl Zeiss Meditec, Jena, Alemanha). O comprimento axial, a espessura central da córnea, a profundidade da câmara anterior, a espessura da lente e as medidas ceratométricas foram avaliados a olho nu e enquanto usavam lentes de contato gelatinosas de três diferentes potências (-1,5, -3,0 e +2,0 D). Resultados: Houve alterações significativas no comprimento axial, espessura central da córnea, profundidade da câmara anterior e medidas ceratométricas com as lentes de contato gelatinosas em comparação com as a olho nu (p<0,001). No entanto, não houve diferenças significativas nos resultados de espessura do cristalino entre o olho nu e enquanto usava as três lentes de contato gelatinosas (p>0,5). As alterações de comprimento axial, espessura central da córnea e profundidade da câmara anterior foram específicas da lente e dependentes da espessura da lente usada. Conclusões: As medições da espessura da lente baseadas na tomografia de coerência óptica da Sept-source, enquanto usam lentes de lentes de contato gelatinosas, são comparáveis às do olho nu. Entretanto, a es pessura e o desenho óptico da lente de contato gelatinosa podem levar a diferenças significativas no comprimento axial, na espessura central da córnea, na profundidade da câmara anterior e nas medidas ceratométricas.


Assuntos
Humanos , Adulto , Biometria/métodos , Lentes de Contato , Tomografia de Coerência Óptica/métodos , Comprimento Axial do Olho/anatomia & histologia , Comprimento Axial do Olho/diagnóstico por imagem , Segmento Anterior do Olho/anatomia & histologia , Segmento Anterior do Olho/diagnóstico por imagem , Valores de Referência , Reprodutibilidade dos Testes , Análise de Variância , Estatísticas não Paramétricas , Estudos Cross-Over
10.
Arq Bras Oftalmol ; 82(2): 129-135, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30726404

RESUMO

PURPOSE: To determine the reliability of swept- source optical coherence tomography in cases in which soft contact lenses cannot be removed when acquiring biometric measurements. METHODS: Eight subjects were included and only one eye per participant was analyzed. Each eye was measured six times by swept-source optical coherence tomography with the IOLMaster 700 instrument (Carl Zeiss Meditec, Jena, Germany). Axial length, central corneal thickness, anterior chamber depth, lens thickness, and keratometric measurements were evaluated for the naked eye and while wearing soft contact lenses of three different powers (-1.5, -3.0, and +2.0 D). RESULTS: There were statistically significant changes in axial length, central corneal thickness, anterior chamber depth, and keratometric measurements with soft contact lenses as compared to the naked eye (p<0.001). However, there were no significant differences in lens thickness outcomes between the naked eye and while wearing the three soft contact lenses (p>0.5). The changes in axial length, central corneal thickness, and anterior chamber depth were lens-specific and dependent on the thickness of the lens used. CONCLUSIONS: Sept-source optical coherence tomography based lens thickness measurements while wearing soft contact lenses are comparable to those of the naked eye. However, the thickness and the optical design of the soft contact lens may lead to significant differences in the axial lengh, central corneal thickness, anterior chamber deph, and keratometric measurements.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Segmento Anterior do Olho/diagnóstico por imagem , Comprimento Axial do Olho/anatomia & histologia , Comprimento Axial do Olho/diagnóstico por imagem , Biometria/métodos , Lentes de Contato , Tomografia de Coerência Óptica/métodos , Adulto , Análise de Variância , Estudos Cross-Over , Humanos , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não Paramétricas
11.
J Optom ; 12(2): 131-140, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30393001

RESUMO

PURPOSE: To compare the shape of the anterior sclera of candidates to scleral lens (ScCL) fitting with regular and irregular corneas and analyze the changes induced in the shape of the sclero-conjunctiva after ScCL wear. METHODS: Thirty-five eyes of 18 subjects (19 eyes with irregular corneas and 16 with regular corneas) were consecutively recruited. Three measures of sclero-conjunctival shape were taken with Eye Surface Profiler (ESP, Eaglet Eye, Houten, The Netherlands). Tangent angles and ocular sagittal heights (OC-SAG) were analyzed at different chords from 13 to 17mm in the nasal, temporal, superior and inferior regions. The 19 eyes with irregular cornea were selected to wear ScCL and the changes in their sclero-conjunctival surface parameters were compared before and after 3h of lens wear. RESULTS: Irregular corneas showed higher OC-SAG values than regular corneas in all the chords analyzed, with statistical significant differences in the temporal region. Regarding tangent angles, regular corneas showed lower values (flatter surface), with statistical significant differences at 8 and 8.50mm on the nasal and 8.50mm on the temporal region. Some changes were seen in sclero-conjuctival shape after short-term ScCL wear. There was an augment in OC-SAG after 3h of scleral lens wear and a reduction on tangent angles, namely on the nasal region at 7.5mm and 8.00mm chord lengths, which is coincidental with the landing zone of ScCL. CONCLUSIONS: ESP shows mild differences in scleral shape between eyes with regular and irregular corneas. ESP might be valuable in quantifying the mechanical impact of the ScCL on the anterior eye surface.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Túnica Conjuntiva/anatomia & histologia , Lentes de Contato Hidrofílicas , Desenho de Prótese , Ajuste de Prótese/métodos , Esclera , Adulto , Análise de Variância , Topografia da Córnea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
12.
Zhonghua Yan Ke Za Zhi ; 54(11): 820-826, 2018 Nov 11.
Artigo em Chinês | MEDLINE | ID: mdl-30440152

RESUMO

Objective: To compare the difference of anterior segment structure between Chinese Han people and American Caucasians, and to explore the confounding factors of anterior chamber angle. Methods: Cross-sectional study. The study was designed to include two healthy groups of Chinese Han people (enrolled from Department of Ophthalmology, Peking University Third Hospital) and American Caucasians (enrolled from Department of Ophthalmology, University of California, San Francisco) from May 2008 to December 2010, each with approximately 120 participants, including 15 persons of each gender in each decade between 40 and 80 years of age. The parameters of the anterior segment were measured by the automatic refractive test, A-ultrasound and ultrasound biomicroscopy. Differences between the two groups were compared with the independent-sample t test or Wilcoxon two-sample test for continuous variable data and the χ(2) test for classified variable data. Multiple linear regression models were performed to analyze the associated factors of anterior chamber angle. Results: There were 118 subjects (118 eyes) and 117 subjects (117 eyes) enrolled in the Chinese and American Caucasians groups, respectively. Compared to Caucasians, Chinese had smaller A-ultrasound measured anterior chamber depth [(3.03±0.34) mm vs. (3.38±0.36) mm, t=-5.791, P<0.001], smaller relative lens position [0.227 (0.198, 0.256) vs. 0.235 (0.191, 0.262), Z=-3.063, P=0.002], smaller axial length [23.3 (20.9,28.3) mm vs. 24.2 (20.8,28.5) mm, Z=-5.510, P<0.001], smaller iris root distance [0.111 (0.000, 0.401) mm vs. 0.142 (0.000, 0.451) mm, Z=-3.188, P=0.001], smaller ciliary body thickness at 1 mm posterior to the scleral spur [0.661 (0.424, 0.892) mm vs. 0.716 (0.467, 0.942) mm, Z=-3.456, P=0.001], smaller trabecular ciliary process distance [0.780 (0.410, 1.400) mm vs. 0.930 (0.420, 1.470) mm, Z=-3.191, P=0.001], smaller trabecular ciliary process angle [73.4° (36.3°, 115.3°) vs. 81.1° (47.9°, 147.9°), Z=-3.407, P=0.001], smaller angle opening distance at 500 µm (AOD500) [0.181 (0.000, 0.703) mm vs. 0.264 (0.000, 0.806) mm, Z=-3.444, P=0.001], smaller angle recess area (ARA) [0.118 (0.011, 0.457) mm(2) vs. 0.179 (0.000, 0.626) mm(2), Z=-3.814, P<0.001], larger spherical equivalent [0.40 (-5.80, 4.00) D vs. -0.70 (-8.00, 4.00) D, Z=-5.454, P<0.001], larger lens thickness [(4.62±0.40) mm vs. (4.52±0.40) mm, t=2.077, P=0.039] and larger iris thickness [0.430 (0.280, 0.600) mm vs. 0.410 (0.240, 0.580) mm, Z=-2.263, P=0.024]. On average, with each decade of the increased age, Chinese had a greater decrease in the AOD500 than Caucasians (0.040 mm in Chinese vs. 0.030 mm in Caucasians), while the angle recess area decreased at the same rate (0.020 mm(2) in both groups). After adjusted for age, gender, spherical equivalent, axial length and other parameters of the anterior segment, the trabecular ciliary process angle [for AOD500, standardized regression coefficient (SRC)=0.487, R(2)=0.549, P<0.001; for ARA, SRC=0.372, R(2)=0.502, P<0.001] and anterior chamber depth (for AOD500, SRC=0.413, R(2)=0.476, P<0.001; for ARA, SRC=0.331, R(2)=0.403, P<0.001) were the main factors of anterior chamber angle parameters for Chinese and Caucasians, respectively. Conclusions: Compared with age and gender matched American Caucasians, Chinese Han people have more crowded anterior chambers and narrower anterior chamber angles. The more anteriorly positioned ciliary processes and shallower anterior chambers are the main factors that contributed to more crowded anterior chambers in Chinese Han people and American Caucasians, respectively. (Chin J Ophthalmol, 2018, 54: 820-826).


Assuntos
Segmento Anterior do Olho , Glaucoma de Ângulo Fechado , Adulto , Idoso , Idoso de 80 Anos ou mais , Câmara Anterior , Segmento Anterior do Olho/anatomia & histologia , Segmento Anterior do Olho/diagnóstico por imagem , Grupo com Ancestrais do Continente Asiático , China , Estudos Transversais , Glaucoma de Ângulo Fechado/diagnóstico por imagem , Gonioscopia , Humanos , Pressão Intraocular , Iris , Pessoa de Meia-Idade , Tomografia de Coerência Óptica , Estados Unidos
13.
Clinics (Sao Paulo) ; 73: e491, 2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30281681

RESUMO

OBJECTIVE: To evaluate the relationship of biomechanical properties, corneal hysteresis and corneal resistance factor with age, sex and various corneal parameters measured with a Pentacam in normal subjects. METHODS: A total of 226 eyes from 113 patients were enrolled in this study. The subjects underwent Ocular Response Analyzer and Pentacam evaluations. A varying-intercept multilevel regression was implemented using Bayesian inference. The predictor variables were age, sex, central corneal thickness, corneal volume at a 7-mm diameter, anterior chamber angle and volume, anterior chamber depth, mean radius of the corneal curvature and corneal astigmatism. RESULTS: Corneal hysteresis ranged from 5.5 to 14.8 mmHg (mean 10.42±1.74 mmHg), and the corneal resistance factor ranged from 5.7 to 15.5 mmHg (mean 10.23±1.88 mmHg). No predictor variable other than gender and central corneal thickness had a significant correlation with either corneal hysteresis or corneal resistance factor. Corneal hysteresis was positively associated with female sex and with central corneal thickness, and corneal resistance factor was positively associated with central corneal thickness. CONCLUSION: Despite the associations found, only a small fraction of the variance in biomechanical measurements could be explained by the descriptors that were evaluated, indicating the influence of other corneal aspects on the biomechanical characteristics.


Assuntos
Segmento Anterior do Olho/fisiologia , Córnea/fisiologia , Segmento Anterior do Olho/anatomia & histologia , Teorema de Bayes , Fenômenos Biomecânicos/fisiologia , Córnea/anatomia & histologia , Feminino , Humanos , Pressão Intraocular/fisiologia , Masculino , Tonometria Ocular
14.
Invest Ophthalmol Vis Sci ; 59(12): 5176-5187, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30372744

RESUMO

Purpose: To investigate diurnal variations in anterior and posterior segment biometry and assess differences between emmetropic and myopic adults. Methods: Healthy subjects (n = 42, 23-41 years old) underwent biometry and spectral-domain optical coherence tomography imaging (SD-OCT) every 4 hours for 24 hours. Subjects were in darkness from 11:00 PM to 7:00 AM. Central corneal thickness, corneal power, anterior chamber depth, lens thickness, vitreous chamber depth, and axial length were measured. Thicknesses of the total retina, photoreceptor outer segments + RPE, photoreceptor inner segments, and choroid over a 6-mm annulus were determined. Results: All parameters except anterior chamber depth demonstrated significant diurnal variations, with no refractive error differences. Amplitude of choroid diurnal variation correlated with axial length (P = 0.05). Amplitude of axial length variation (35.71 ± 19.40 µm) was in antiphase to choroid variation (25.65 ± 2.01 µm, P < 0.001). The central 1-mm retina underwent variation of 5.03 ± 0.23 µm with a peak at 12 hours (P < 0.001), whereas photoreceptor outer segment + RPE thickness peaked at 4 hours and inner segment thickness peaked at 16 hours. Diurnal variations in retina and choroid were observed in the 3- and 6-mm annuli. Conclusions: Diurnal rhythms in anterior and posterior segment biometry were observed over 24 hours in adults. Differences in baseline parameters were found between refractive error groups, and choroid diurnal variation correlated with axial length. The retina and choroid exhibited diurnal thickness variations in foveal and parafoveal regions.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Ritmo Circadiano/fisiologia , Emetropia/fisiologia , Miopia/fisiopatologia , Segmento Posterior do Olho/anatomia & histologia , Adulto , Comprimento Axial do Olho , Biometria , Feminino , Voluntários Saudáveis , Humanos , Interferometria/métodos , Lasers , Masculino , Tomografia de Coerência Óptica , Adulto Jovem
16.
Prog Retin Eye Res ; 64: 77-83, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29374584

RESUMO

Cataract extraction is a safe and effective surgery that has a lowering effect on the intraocular pressure. The specific mechanisms for this effect are still unclear. A direct inflammatory effect on the trabecular meshwork, alteration of the blood aqueous barrier, changes in the ciliary body and mechanical changes of the anterior segment anatomy are the key to understand cataract surgery and it's effects on aqueous humor dynamics. Additionally, with the advent of AS OCT, changes in the anterior segment of the eye have been studied and several parameters (such as lens vault, angle opening distance and anterior chamber depth) have been identified as predictors of intraocular pressure change. In eyes with narrow angles there is a greater drop in intraocular pressure after cataract surgery and it is correlated with parameters related to anterior chamber space. It is safe to affirm that cataract surgery is an important part of the modern glaucoma treatment and evidence should be analyzed as part of a bigger picture in order to more accurately understand its clinical relevance.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Catarata , Pressão Intraocular/fisiologia , Hipertensão Ocular/cirurgia , Facoemulsificação , Catarata/fisiopatologia , Glaucoma/fisiopatologia , Glaucoma/cirurgia , Humanos , Hipertensão Ocular/fisiopatologia
17.
Cont Lens Anterior Eye ; 41(2): 205-213, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29129479

RESUMO

PURPOSE: The purpose of this study was to evaluate the shape of the anterior sclera by measuring the sagittal height and corneoscleral transition angles in the four cardinal and four oblique segments of the eye. MATERIALS AND METHODS: In this study, 78 normal eyes of 39 subjects were evaluated. The sagittal height, corneoscleral angle and scleral angle were measured at three chord lengths (10.0mm, 12.8mm and 15.0mm) in all eight segments of the anterior eye using optical coherence tomography (Zeiss Visante AS-OCT). Scleral toricity was calculated for each eye, defined as the greatest sagittal height difference found between two perpendicular meridians. RESULTS: At a 12.8mm chord length, the shape of the anterior eye was found to be nearly rotationally symmetric, and at a chord of 15.0mm the shape became more asymmetric. The average sagittal heights of the eight segments at a 12.8mm chord ranged from 2890µm to 2940µm; at a 15.0mm chord they ranged from 3680µm to 3790µm. The average scleral angles at a 15.0mm chord ranged from 35.17° to 38.82°. Significant differences between opposing segments were found in the sagittal height and scleral angle measurements at a chord of 15.0mm (sagittal height p≤0.0021; scleral angle p≤0.0105). The nasal measurements revealed flatter scleral angles and concave corneoscleral transitions, whereas temporal scleral angles were steeper, with tangential or convex corneoscleral transitions. CONCLUSION: These findings are important to consider when designing and fitting contact lenses that rest beyond the boundaries of the limbus, such as scleral lenses.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Lentes de Contato Hidrofílicas , Desenho de Prótese , Ajuste de Prótese , Esclera , Adulto , Segmento Anterior do Olho/diagnóstico por imagem , Topografia da Córnea , Estudos Transversais , Feminino , Humanos , Masculino , Tomografia de Coerência Óptica , Adulto Jovem
18.
J Glaucoma ; 27(1): 16-21, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29194197

RESUMO

PURPOSE: To examine the diurnal variation of static and dynamic anterior segment parameters in young, healthy eyes by comparing anterior segment optical coherence tomography (AS-OCT) measurements obtained in the morning and evening and also in the light and dark. METHODS: Twenty-two subjects ranging from 19 to 47 years of age with no past ocular history were selected. Imaging was performed with the Tomey CASIA2 AS-OCT device in 2 fixed lighting environments, light and dark, between the hours of 08:30 to 10:00 and 17:30 to 19:00. Four AS-OCT images were analyzed per eye. Pupil diameter (PD), iris area (IA), iris curvature (IC), anterior chamber depth (ACD), lens vault (LV), anterior chamber width (ACW), anterior chamber area (ACA), angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), and trabecular iris angle (TIA) were measured. RESULTS: Pupil diameter was similar between the AM and PM groups in the light (P=0.89) and dark (P=0.51). There was no significant difference between AM and PM measurement values for any of the static or dynamic parameters in the light (P>0.39) and dark (P>0.31). Intraclass correlation coefficients (ICC) demonstrated excellent agreement between AM and PM measurement values in the light (ICC>0.81) and dark (ICC>0.93). In addition, there was no significant difference between AM and PM angle opening distance at 500 µm measurement values in the light (P>0.34) and dark (P>0.40) when each of 8 angle sectors was analyzed individually. CONCLUSIONS: No significant diurnal variation of static or dynamic anterior segment parameter measurements was detected in the light and dark. Diurnal variation of these parameters does not regularly occur in young, healthy eyes.


Assuntos
Segmento Anterior do Olho/anatomia & histologia , Ritmo Circadiano/fisiologia , Tomografia de Coerência Óptica/métodos , Adulto , Segmento Anterior do Olho/diagnóstico por imagem , Adaptação à Escuridão , Feminino , Humanos , Pressão Intraocular , Iris/anatomia & histologia , Cristalino/anatomia & histologia , Masculino , Pessoa de Meia-Idade , Pupila/fisiologia , Malha Trabecular/anatomia & histologia , Adulto Jovem
19.
Clinics ; 73: e491, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-952791

RESUMO

OBJECTIVE: To evaluate the relationship of biomechanical properties, corneal hysteresis and corneal resistance factor with age, sex and various corneal parameters measured with a Pentacam in normal subjects. METHODS: A total of 226 eyes from 113 patients were enrolled in this study. The subjects underwent Ocular Response Analyzer and Pentacam evaluations. A varying-intercept multilevel regression was implemented using Bayesian inference. The predictor variables were age, sex, central corneal thickness, corneal volume at a 7-mm diameter, anterior chamber angle and volume, anterior chamber depth, mean radius of the corneal curvature and corneal astigmatism. RESULTS: Corneal hysteresis ranged from 5.5 to 14.8 mmHg (mean 10.42±1.74 mmHg), and the corneal resistance factor ranged from 5.7 to 15.5 mmHg (mean 10.23±1.88 mmHg). No predictor variable other than gender and central corneal thickness had a significant correlation with either corneal hysteresis or corneal resistance factor. Corneal hysteresis was positively associated with female sex and with central corneal thickness, and corneal resistance factor was positively associated with central corneal thickness. CONCLUSION: Despite the associations found, only a small fraction of the variance in biomechanical measurements could be explained by the descriptors that were evaluated, indicating the influence of other corneal aspects on the biomechanical characteristics.


Assuntos
Humanos , Masculino , Feminino , Córnea/fisiologia , Segmento Anterior do Olho/fisiologia , Tonometria Ocular , Fenômenos Biomecânicos/fisiologia , Teorema de Bayes , Córnea/anatomia & histologia , Pressão Intraocular/fisiologia , Segmento Anterior do Olho/anatomia & histologia
20.
Arq Bras Oftalmol ; 80(6): 364-368, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29267571

RESUMO

PURPOSE: To assess changes in anatomic structures in the anterior eye segment in terms of axial lengths with accommodation via optical coherence tomography. METHODS: In this observational study, 25 eyes of 25 healthy adults were examined using the Visante® omni optical coherence tomography system. Central corneal thickness, anterior chamber depth, central lens thickness, and anterior segment length were assessed. The evaluated parameters were obtained with accommodation using different stimulus vergences, namely 0.0, -1.0, -2.0, and -3.0 D. Variation of these parameters was compared among different levels of accommodation. RESULTS: Central corneal thickness was not altered at any stimulus vergence during accommodation (p>0.05). Conversely, anterior chamber depth was significantly reduced (p<0.05), whereas central lens thickness was significantly increased (p<0.05). Anterior segment length also increased with accommodation (p<0.05), indicating backward movement of the posterior pole. CONCLUSIONS: There are significant variations in anterior segment lengths that occur with accommodation. Studying these changes will provide useful information regarding the accommodation mechanism that can improve our understanding of this process and facilitate clinical decision-making by practitioners.


Assuntos
Acomodação Ocular/fisiologia , Segmento Anterior do Olho/anatomia & histologia , Segmento Anterior do Olho/diagnóstico por imagem , Tomografia de Coerência Óptica , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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