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PURPOSE: To assess ciliary muscle (CM) and anterior scleral thickness (AST) dimensions in vivo in high myopia using swept-source optical coherence tomography (SS-OCT) and to compare with emmetropic and hyperopic subjects. METHODS: Cross-sectional study that included 34 high myopic patients (≥ -6 diopters [D]), 90 emmetropes (-1 to +1 D) and 38 hyperopic patients (≥ +3.5 D). CM thickness (CMT) and AST were measured in the temporal and nasal quadrants at 1, 2, and 3 mm from the scleral spur using SS-OCT. In addition, the length of the CM (CML) was evaluated. RESULTS: The dimensions of the CML and the CMT at any of their measurement points were greater in high myopes and emmetropes than in hyperopes, both in the nasal and temporal quadrants (P < .001). However, there were no differences between high myopes and emmetropes for any of the parameters (P ≥ .076) except for the CMT at 3 mm in the temporal quadrant (P < .001). There were no differences in the AST between high myopes, emmetropes and hyperopes, in any of the measurement points or quadrants studied (P > .05). CONCLUSIONS: The SS-OCT allows to measure the CM in vivo, not observing differences in its dimensions between high myopes and emmetropes, but they were smaller in hyperopes. In the measurement of the anterior sclera, no differences were observed between the three groups analyzed according to refraction.
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Hiperopia , Miopia , Humanos , Tomografia de Coerência Óptica/métodos , Esclera/diagnóstico por imagem , Estudos Transversais , Miopia/diagnóstico por imagem , MúsculosRESUMO
Nanophthalmos is a rare congenital condition of the eyeball that is characterised by a smaller size of the anterior and posterior segments without associated ocular malformations. Typical features that have traditionally been described in these eyes are short axial length, thickened sclera, cornea with a smaller diameter, narrow anterior chamber, and an increased lens to globe volume ratio. However, at present, there is still a lack of recognised diagnostic criteria for nanophthalmos and a classification of its severity. Its clinical relevance stems from the increased risk of multiple ocular conditions, such as high hyperopia, amblyopia, angle-closure glaucoma, retinal detachment, and cataracts. Likewise, in relation to surgery in these eyes, there are particularities in cataract and glaucoma surgery and with a greater risk of associated intra- and postoperative complications. In this way, the treatment of nanophthalmos focuses on controlling the associated eye conditions and reducing and controlling surgical complications. This review aims to update what has been published in recent years regarding nanophthalmos.
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Catarata , Glaucoma de Ângulo Fechado , Hiperopia , Cristalino , Microftalmia , Humanos , Microftalmia/complicações , Microftalmia/diagnóstico , Glaucoma de Ângulo Fechado/complicações , Visão Ocular , Catarata/complicaçõesRESUMO
PURPOSE: To study the biometric modifications of the eyeball during suction in Laser assisted in Situ Keratomileusis (LASIK). METHODS: Observational and cross-sectional study. We studied 43 patients who underwent surgery for myopia and myopic astigmatism. Mean age was 38.3⯱â¯11.5 years, and 19 were female (44.2%). Conventional LASIK surgery with a manual microkeratome was performed. Before and during the suction maneuvre the following parameters were measured using an 11 Mhz biometric probe: aqueous depth (AQD), lens thickness (LT), vitreous cavity length (VCL) and axial length (AXL). Paired t-test was used to compare the biometric measurements before and during suction. RESULTS: The mean spherical equivalent refractive error was -4.5⯱â¯2.3 diopters. During suction, the AQD did not change significantly (pâ¯=â¯0.231). However, AXL and VCL increased by 0.12â¯mm and 0.22â¯mm respectively (pâ¯=â¯0.039 and <0.01) and LT decreased by 0.20â¯mm (pâ¯<â¯0.01). AXL increased in 42% of the eyes and decreased in 16%, VCL increased in 70% of the eyes and decreased in 9%, and the LT was reduced in 67% of the eyes. CONCLUSIONS: Suction maneuvres during LASIK surgery produce changes of little magnitude in the eye globe, mainly a decrease in LT and an increase in VCL and AXL. Therefore, these modifications are expected to produce minimal anatomic alterations.
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Ceratomileuse Assistida por Excimer Laser In Situ , Miopia , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Masculino , Sucção , Estudos Transversais , Miopia/cirurgia , BiometriaRESUMO
PURPOSE: To assess the agreement between the measurements of the distance from the medial rectus muscles insertion to the limbus measured by intra-operative spectral-domain optical coherence tomography (SD-OCT) in consecutive exotropia (cXT). METHODS: An analysis was performed on total of 14 medial rectus (MR) muscles of 14 patients who underwent surgery for the treatment of cXT. The limbus-insertion distance of the MR muscles was measured using preoperative SD-OCT and intraoperatively using a calliper. The intraclass correlation coefficient (ICC) and Bland Altman plots were calculated to determine the agreement between the two methods, as well as the correlation. RESULTS: Mean age was 36.3 ± 16.0 years (range 13-60), with 60% being women. Mean preoperative deviation was 38.7 ± 16.9 prismatic dioptres (PD) (range 16-65), being +1.3 ± 6.3 PD (range -12 to +10 PD) after surgery. Intraoperatively the MR insertion was found at 8.7 ± 2.1 mm (range 5.5-12.0) and by OCT at 7.7 ± 1.2 mm (range 5.3-10.0). The ICC showed a moderate to good agreement (0.659; 95% confidence interval: 0.157-0.885; p < 0.001), with a correlation of R = 0.792 (p = 0.011). A better agreement was observed in those MR that were less retro-inserted. CONCLUSIONS: SD-OCT is able to measure the insertion to the limbus distance of the medial rectus muscles that have been previously operated on, showing moderate to good agreement with intraoperative measurements. However, the agreement was poor in muscles with a large retro-insertion.
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Exotropia , Estrabismo , Adolescente , Adulto , Exotropia/diagnóstico por imagem , Fixadores Externos , Feminino , Humanos , Pessoa de Meia-Idade , Músculos Oculomotores/diagnóstico por imagem , Tomografia de Coerência Óptica , Adulto JovemRESUMO
Monocular elevation deficiency (MED) is characterized by unilateral limitation of supraductions, similar in adduction and abduction, in addition to hypotropia and ptosis. We describe a case of a 62-year-old woman with long-standing left ptosis who was initially operated with a frontal suspension technique. On subsequent examinations, a MED of that eye was found. The passive duction test was positive, so the inferior rectus was recessed. In addition, a modified Nishida technique was performed, consisting of the scleral anchorage of the superior edges of the rectus, medial and lateral, 12mm from the corneal limbus in the superonasal and superotemporal quadrants, respectively. Postoperatively, the left eye presented a minimal hypotropia of 3 PD. This modified technnique used here on the horizontal rectus muscles, turned out to be effective and safe for the correction of MED.
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Blefaroptose , Estrabismo , Blefaroptose/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos , Esclera , Estrabismo/cirurgiaRESUMO
PURPOSE: To evaluate the agreement between Scheimpflug tomography (Pentacam, Oculus) and anterior segment optical coherence tomography (AS-OCT, RTVue 100, Optovue) as well as the reproducibility of each technique in assessing the lens-ICL distance (vault) after implantable collamer lens (ICL) implantation. METHODS: The vault was measured manually with Scheimpflug tomography and AS-OCT. Intraclass correlation coefficients (ICC) and Bland-Altman plots were used to determine the reproducibility of measurements and the agreement between them. Multivariate regression analysis was performed to identify predictors of differences in vault measurements between devices. RESULTS: 80 eyes of 46 ICL patients were analyzed. Mean patient age was 33.8±7.4 years (range, 21 to 51), and 27 (59%) were women. The preoperative spherical equivalent refraction ranged from -26 to 8.5 diopters (D). The mean vault measured by AS-OCT was 558.8±240.2µm (range, 162 - 1220) vs. 430.1±215.3µm (range, 0 to 1070) by Pentacam. AS-OCT yielded vault values, on average, 128.1±64.6µm higher than the Pentacam (range, -22 to 293µm). The ICC values for consistency and absolute agreement were 0.960 and 0.928, respectively. Reproducibility of vault measurements was excellent for both devices (ICC≥0.946). Four parameters-vault, pupil diameter (PD), PD differences between devices, and preoperative spherical equivalent refraction-were significant predictors of differences in vault measurements (adjusted-R2=0.412; P<0.001). CONCLUSIONS: Agreement between AS-OCT and Pentacam for vault measurement was good. Vaults were higher when measured by AS-OCT. These differences are clinically relevant, and therefore these devices cannot be used interchangeably to measure vault.
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Lentes Intraoculares Fácicas , Adulto , Feminino , Humanos , Implante de Lente Intraocular , Pessoa de Meia-Idade , Refração Ocular , Reprodutibilidade dos Testes , Tomografia de Coerência Óptica , Adulto JovemRESUMO
Monocular elevation deficiency (MED) is characterized by unilateral limitation of supraductions, similar in adduction and abduction, in addition to hypotropia and ptosis. We describe a case of a 62-year-old woman with long-standing left ptosis who was initially operated with a frontal suspension technique. On subsequent examinations, a MED of that eye was found. The passive duction test was positive, so the inferior rectus was recessed. In addition, a modified Nishida technique was performed, consisting of the scleral anchorage of the superior edges of the rectus, medial and lateral, 12mm from the corneal limbus in the superonasal and superotemporal quadrants, respectively. Postoperatively, the left eye presented a minimal hypotropia of 3 PD. This modified technnique used here on the horizontal rectus muscles, turned out to be effective and safe for the correction of MED.
RESUMO
PURPOSE: To assess the agreement between the intraoperative measurements of the distance from the medial rectus muscles insertion to the limbus and preoperative spectral-domain optical coherence tomography (SD-OCT) in consecutive exotropia (cXT). METHODS: An analysis was performed on total of 14 medial rectus (MR) muscles of 14 patients who underwent surgery for the treatment of cXT. The limbus-insertion distance of the MR muscles was measured using preoperative SD-OCT and intraoperatively using a calliper. The intraclass correlation coefficient (ICC) and Bland Altman plots were calculated to determine the agreement between the two methods, as well as the correlation. RESULTS: Mean age was 36.3±16.0 years (range 13-60), with 60% being women. Mean preoperative deviation was 38.7±16.9 prismatic dioptres (PD) (range 16 to 65), being +1.3±6.3 PD (range -12 to +10 PD) after surgery. Intraoperatively the MR insertion was found at 8.7±2.1mm (range 5.5 - 12.0) and by OCT at 7.7±1.2mm (range 5.3 - 10.0). The ICC showed a moderate to good agreement (0.659; 95% confidence interval: 0.157-0.885; P<.001), with a correlation of R=0.792 (P=.011). A better agreement was observed in those MR that were less retro-inserted. CONCLUSIONS: SD-OCT is able to measure the insertion to the limbus distance of the medial rectus muscles that have been previously operated on, showing moderate to good agreement with intraoperative measurements. However, the agreement was poor in muscles with a large retro-insertion.
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INTRODUCTION: To assess if there are any differences in macular and papillary thickness using optical coherence tomography (OCT) in patients with attention deficit hyperactivity disorder (ADHD) compared with a control group, including if there are differences between ADHD patients with and without treatment. METHODS: Prospective observational study including 92 eyes of 46 patients divided into 2 groups: 46 eyes of 23 patients with ADHD, and a control group of 46 eyes of 23 healthy patients. The group of patients with ADHD was subdivided into those on treatment with methylphenidate (n=28) and those not on treatment (n=18). The macular thickness, the ganglion cell complex (GCC), and the retinal nerve fibre layer (RNFL) at the papillary level were measured in 12 sectors. RESULTS: A lower central macular thickness was observed in the ADHD patients than in the controls (257.4±20µm versus 267.5±20µm, P=.013), with no differences observed in the GCC (P=.566), or in the RNFL (P=.095). There were no differences in the patients with ADHD with and without treatment, as regards macular thickness and the GCC (P=.160 and P=.375 respectively), but a lower foveal thickness (P=.018) and RNFL in 5/12 sectors at the papillary level (P=.033) were observed in those without treatment. CONCLUSIONS: A lower macular thickness was observed in patients with ADHD than in controls. In addition, patients with ADHD without treatment had a lower thickness of the fovea and RNFL than those patients on treatment.
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Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Estimulantes do Sistema Nervoso Central/farmacologia , Estimulantes do Sistema Nervoso Central/uso terapêutico , Macula Lutea/efeitos dos fármacos , Macula Lutea/diagnóstico por imagem , Metilfenidato/farmacologia , Metilfenidato/uso terapêutico , Disco Óptico/efeitos dos fármacos , Disco Óptico/diagnóstico por imagem , Tomografia de Coerência Óptica , Adolescente , Criança , Estudos Transversais , Humanos , Macula Lutea/patologia , Disco Óptico/patologia , Tamanho do Órgão , Estudos ProspectivosRESUMO
PURPOSE: To assess the correlation between optic nerve head measurements generated by Fourier-domain (FD) and swept-source (SS) optical coherence tomography (OCT) both in healthy Caucasian subjects and patients with primary open angle glaucoma (POAG). MATERIALS AND METHODS: This was a cross-sectional study of the right eyes of 118 subjects. In each participant, the measurements of disc area, cup to disc ratio (CDR), vertical cup to disc ratio (VCDR), rim area and rim volume were performed consecutively by FD-OCT and then SS-OCT. Participant age, gender and spherical equivalent were also recorded. Agreement between the two devices was assessed through intraclass correlation coefficients (ICC) and Bland-Altman plots. RESULTS: The study sample consisted of 95 healthy eyes and 23 eyes with glaucoma. Mean participant age was 48.6±20.0 years, 54.2% were female, and mean spherical equivalent was -1.6±3.0 diopters. FD-OCT and SS-OCT measurements were respectively: mean disc area 1.79±0.3 vs 1.83±0.3 mm2 (ICC=0.71), mean CDR 0.38±0.2 vs 0.33±0.2 (ICC=0.91), mean VCDR 0.58±0.2 vs 0.52±0.2 (ICC=0.92), mean rim area 1.05±0.4mm2 vs 1.03±0.5mm2 (ICC=0.29), and mean rim volume 0.14±0.11 vs 0.21±0.17mm3 (ICC=0.53). Good agreement between the devices was noted for rim area and rim volume in glaucoma subjects (ICC=0.76 and 0.68 respectively), while weak agreement was observed for these variables in healthy subjects (ICC≤0.50). CONCLUSIONS: The CDR and VCDR measurements provided by FD and SS OCT showed excellent agreement for the overall sample. When the devices were used for rim measurements, agreement was excellent only in the POAG patients.
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Glaucoma/diagnóstico , Disco Óptico/diagnóstico por imagem , Disco Óptico/patologia , Tomografia de Coerência Óptica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos Transversais , Feminino , Glaucoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Nervo Óptico/diagnóstico , Doenças do Nervo Óptico/patologia , Tamanho do Órgão , Reprodutibilidade dos Testes , Adulto JovemRESUMO
Complement-mediated membranoproliferative glomerulonephritis is a rare progressive glomerular disease. In some patients it can be associated with retinal lesions. Therefore, the purpose of this study was to assess a case series with this diagnosis in our hospital. A cross-sectional study was conducted on 8 patients diagnosed with complement-mediated membranoproliferative glomerulonephritis. Funduscopy, optical coherence tomography (OCT) and Swept Source domain OCT angiography were performed. Only 1 of the 8 patients showed drusen-like deposits that were located under the retinal pigment epithelium in the OCT, with the presence of associated choroidal neovascularization being ruled out in OCT angiography. Therefore, membranoproliferative glomerulonephritis may produce retinal alterations with drusen or retinal pigment epithelium detachment, and requires an appropriate differential diagnosis to be made with age-related macular degeneration. The follow-up of these patients is important in order to detect vision-threatening complications.
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Glomerulonefrite Membranoproliferativa/complicações , Doenças Retinianas/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia , Ativação do Complemento , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oftalmoscopia , Drusas Retinianas/etiologia , Tomografia de Coerência Óptica , Adulto JovemRESUMO
PURPOSE: To assess the extraocular muscle thickness and chemosis after treatment with tocilizumab in patients with active Graves' ophthalmopathy by optical coherence tomography. METHODS: Case series of five patients with active Graves' ophthalmopathy (clinical activity score ≥4/10) treated with 4 doses of tocilizumab. These patients had been previously treated with corticosteroids with no response. Spectral-domain optical coherence tomography was employed to determine lateral and medial rectus muscle thickness and chemosis before and after 4 doses of tocilizumab given monthly. Scanning was performed at 3 and 9 o'clock (nasal and temporal). RESULTS: The study included four women and one man with a median age of 52 years (range: 38-73). Median Graves' ophthalmopathy activity duration was 17 months (12-18). Median medial rectus and determine lateral thicknesses pre-treatment were 249µm (174-366) and 337µm (142-443), respectively. Median chemosis was 409µm (290-610). After tocilizumab treatment, median muscle thicknesses reduced to 157µm (88-187) and 197µm (99-290), respectively (P=.043; Wilcoxon) and chemosis to 59µm (0-78). Median clinical activity score decreased from 5 (4-8) to 1 (0-3). CONCLUSIONS: A reduction in extraocular muscle thickness and chemosis was observed after treatment with tocilizumab in Graves' ophthalmopathy patients using an optical coherence tomography, so this technique could be a useful complementary technique to assess the therapeutic responses.
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Anticorpos Monoclonais Humanizados/uso terapêutico , Oftalmopatia de Graves/tratamento farmacológico , Músculos Oculomotores/patologia , Tomografia de Coerência Óptica , Adulto , Idoso , Antropometria , Estudos de Casos e Controles , Doenças da Túnica Conjuntiva/tratamento farmacológico , Doenças da Túnica Conjuntiva/etiologia , Doenças da Túnica Conjuntiva/patologia , Quimioterapia Combinada , Edema/tratamento farmacológico , Edema/etiologia , Edema/patologia , Feminino , Oftalmopatia de Graves/complicações , Oftalmopatia de Graves/patologia , Humanos , Masculino , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: To report reference values for the horizontal rectus muscles thickness using Spectral Domain optical coherence tomography (SD-OCT), and to evaluate whether there are any correlations between the muscle thickness and gender, age, or axial length (AL). MATERIAL AND METHODS: A cross-sectional study was conducted on 131 right eyes of healthy subjects. The gender and age were recorded, and axial length was measured using an optical biometer. The medial rectus (MR) muscle thickness was measured at 7.2 and 9.2mm from the limbus, and the lateral rectus (LR) at 8.5 and 10.5mm from the limbus using OCT. A multivariate model was adjusted to determine whether gender, age, and axial length could have an impact on the muscle thickness. RESULTS: Mean age was 43.3±20.9 years (range 6-86), and 59% were women. Mean AL was 24.9±2.7mm (range: 20.4-33.8). Mean thickness was 188.5±51.2µm (range 69-342) for the LR at 8.5 and 186.5±45.9µm (range 75-269) at 10.5mm, and for the MR, 158.1±39.1µm (range 69-273) at 7.2mm and 193.7±55.9µm (range 105-386) at 9.2mm. A correlation was observed between the AL and MR thickness (R=-.255; P=.023) while no correlation was observed for the LR (P≥0.203). No correlations were found between thickness and gender or thickness and age (P≥0.125). CONCLUSIONS: The reference ranges of the horizontal rectus muscles thickness was described using SD-OCT, observing an association between the AL and the MR thickness.
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Antropometria/métodos , Músculos Oculomotores/anatomia & histologia , Tomografia de Coerência Óptica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Adulto JovemRESUMO
PURPOSE: To analyze the agreement between Pentacam and optical coherence tomography (OCT) in the assessment of trabecular-iris angle (TIA) width in a large population of normal subjects. METHODS: A cross-sectional study was performed in 989 right eyes of 989 healthy subjects. The trabecular-iris angle (TIA) was measured in the temporal and nasal quadrants using the Pentacam (Oculus, Wetzlar, Germany), a device based on Scheimpflug technology and RTVue 100 OCT (Optovue, Fremont, CA, USA). Intraclass correlation coefficients (ICC) and Bland-Altman plots were used to evaluate agreement between these devices. RESULTS: Mean age was 49.1±15.2 years (18-84); 61% were women and spherical error range was -14 to 8.25. TIA could be measured by OCT in 94.9% and 94.1% in the temporal and nasal quadrants, with a mean value of 35.8±13.2 degrees (2.5-78.7) and 35.7±12.9 degrees (2.2-76.8) respectively. TIA was able to be measured by Pentacam in 95.2% and 95% in the temporal and nasal quadrants and means were 35.7±7.3 degrees (11-74.2) and 36.4±8.2 degrees (14.5-64) respectively. An ICC of 0.378 (95% confidence interval [CI], 0.322-0.431) and 0.589 (95% CI 0.546-0.629) for the temporal and nasal quadrants was obtained, showing moderate agreement between the devices. Bland-Altman plots revealed that, compared with OCT, Pentacam tends to overestimate measurements in narrow angles and underestimate these in open angles. CONCLUSIONS: Agreement between OCT and Pentacam was mediocre, indicating the two devices are not interchangeable when used to measure angle width.
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Câmara Anterior/diagnóstico por imagem , Técnicas de Diagnóstico Oftalmológico , Iris/diagnóstico por imagem , Tomografia de Coerência Óptica , Malha Trabecular/diagnóstico por imagem , Adolescente , Adulto , Estudos Transversais , Técnicas de Diagnóstico Oftalmológico/instrumentação , Feminino , Glaucoma/diagnóstico , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Tomografia de Coerência Óptica/instrumentação , Tomografia de Coerência Óptica/métodos , Gravação em Vídeo/instrumentação , Gravação em Vídeo/métodos , Adulto JovemRESUMO
OBJECTIVE: To evaluate different anterior segment parameters in eyes with pseudoexfoliation (PSX), fellow eyes, and controls using optical coherence tomography and a Scheimpflug imaging system. METHODS: Three groups were studied: 44 eyes of 44 patients with PSX, 30 clinically unaffected fellow eyes, and 148 eyes of 148 healthy controls. The anterior chamber depth and volume, corneal volume and thickness, pupil diameter and corneal densitometry were measured using a Scheimpflug imaging system (Pentacam, Oculus Inc.; Wetzlar, Germany). The angle width, the length and area of the trabecular meshwork, and the iris thickness were measured using an optical coherence tomography RTVue 100 device (Optovue, Fremont, CA, USA). The presence of PSX deposits was also assessed by OCT. RESULTS: There were no differences in the anterior chamber volume or depth in the corneal volume or central thickness (P≥.228). The corneal densitometry was similar between PSX and fellow eyes; however it was greater than in the control group (P<.001). As regards the parameters measured by OCT, there were no differences in the angle width or in the trabecular meshwork size between the 3 groups; however, the iris was thinner in controls (P=.005). In all patients the PSX deposits were correctly visualised by OCT after the identification by biomicroscopy. CONCLUSIONS: There were no differences in the anterior segment biometric measurements between patients with PSX and controls, although the corneal densitometry and iris thickness were greater in the PSX and fellow eyes groups.
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Segmento Anterior do Olho/diagnóstico por imagem , Síndrome de Exfoliação/diagnóstico por imagem , Tomografia de Coerência Óptica , Idoso , Estudos Transversais , Técnicas de Diagnóstico Oftalmológico/instrumentação , Feminino , Humanos , MasculinoRESUMO
OBJECTIVE: To assess the agreement between intraoperative measurements of the limbus-insertion distance of the extraocular muscles with those measured by spectral domain optical coherence tomography. METHODS: An analysis was made of a total of 67 muscles of 21 patients with strabismus. The limbus-insertion distance of the horizontal rectus muscles were measured using pre-operative SD-OCT and intra-operatively in 2 ways: 1) direct, after a conjunctival dissection in patients who underwent surgery, or 2) transconjunctival in patients who were treated with botulinum toxin, or in those who were not going to be operated. The intraclass correlation coefficient and Bland-Altman plots were calculated to determine the concordance between the 2 methods. RESULTS: The mean age was 45.9 ±20.9 years (range 16 to 85), with 52% being women. The percentage of identification by direct intraoperative measurement was 95.6% (22/23), by transconjunctival intraoperative measurement 90.9% (40/44), and by OCT 85% (57/67), with 22 muscles finally being analysed for the agreement study between direct intraoperative measurement and OCT measurements, and 35 muscles for the agreement between transconjuctival intraoperative measurement and OCT. The intraclass correlation coefficient showed good agreement with OCT and direct intraoperative measurements (0.931; 95% confidence interval (95% CI): 0.839-0.972; P<.001), and with transconjunctival intraoperative measurements (0.889; 95% CI: 0.790-0.942; P<.001). CONCLUSIONS: The SD-OCT is an effective technique to measure the distance from the insertion of the horizontal rectus muscles to the limbus, with a high agreement with intraoperative measurements being demonstrated.