Evaluación del músculo ciliar y del grosor escleral anterior en miopes altos mediante tomografía de coherencia óptica / Assessment of the ciliary muscle and scleral anterior thickness in high myopia by optical coherence tomography

Propósito: Evaluar las dimensiones del músculo ciliar (MC) y del grosor escleral anterior (AST) in vivo en miopes altos mediante tomografía de coherencia óptica de fuente de barrido (SS-OCT) y comparar con sujetos emétropes e hipermétropes.MétodosEstudio transversal en el que se incluyeron 34 miopes altos (≥−6dioptrías [D]), 90 emétropes (−1 a +1D) y 38 hipermétropes (≥+3,5D). Se midieron el grosor del MC (CMT) y el AST en los cuadrantes temporal y nasal a 1, 2 y 3mm del espolón escleral utilizando la SS-OCT. Además, se evaluó la longitud del MC (CML).ResultadosLas dimensiones tanto del CML como del CMT en cualquiera de sus puntos de medida fueron mayores en miopes altos y en emétropes que en hipermétropes, tanto en el cuadrante nasal como en el temporal (p<0,001). Sin embargo, no existieron diferencias entre miopes magnos y emétropes para ninguno de los parámetros (p≥0,076), salvo para el CMT a 3mm en temporal (p<0,001). No existieron diferencias en el AST entre miopes altos, emétropes e hipermétropes, en ninguno de los puntos de medida ni cuadrantes estudiados (p>0,05).ConclusionesLa SS-OCT permite medir el MC in vivo, no observándose diferencias en sus dimensiones entre miopes altos y emétropes, pero sí que fueron menores en hipermétropes. En la medida de la esclera anterior no se observaron diferencias entre los tres grupos analizados según la refracción. (AU)

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.MethodsCross-sectional study that included 34 high myopic patients (≥−6 diopters [D]), 90 emmetropes (−1 to +1D) and 38 hyperopic patients (≥+3.5D). CM thickness (CMT) and AST were measured in the temporal and nasal quadrants at 1, 2, and 3mm from the scleral spur using SS-OCT. In addition, the length of the CM (CML) was evaluated.ResultsThe 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 3mm 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).ConclusionsThe 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. (AU)

Assessment of the ciliary muscle and scleral anterior thickness in high myopia by optical coherence tomography.

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.

Agreement between Fourier-domain and swept-source optical coherence tomography used for optic nerve head measurements.

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.

Evaluación de los signos de la pseudoexfoliación en el segmento anterior mediante tomografía de coherencia óptica y cámara de Scheimpflug / Pseudoexfoliation signs in the anterior segment assessed by optical coherence tomography and Scheimpflug device

Objetivo: Evaluar diferentes parámetros del segmento anterior en ojos con pseudoexfoliación (PSX), ojos contralaterales y controles mediante tomografía de coherencia óptica (OCT) y cámara Scheimpflug. Métodos: Se estudiaron 3 grupos: 44 ojos de 44 pacientes con PSX, 30 ojos contralaterales no afectos y 148 ojos de 148 controles sanos. Mediante la cámara de Scheimpflug (Pentacam, Oculus Inc.; Wetzlar, Alemania) se midieron la profundidad y volumen de la cámara anterior, volumen corneal y paquimetría, diámetro pupilar y densitometría corneal. Mediante OCT RTVue 100 (Optovue, Fremont, CA, EE. UU.) se midieron la abertura angular, la longitud y el área de la malla trabecular, el grosor del iris, y se valoró la visualización de depósitos PSX. Resultados. No se observaron diferencias en cuanto a la profundidad ni volumen de la cámara anterior, ni en el volumen corneal o paquimetría (p≥0,228 en todos los parámetros) entre grupos. Sin embargo, la densitometría corneal fue mayor en PSX y en los ojos contralaterales que en el grupo control (p < 0,001). En cuanto a los parámetros de OCT no existieron diferencias en la abertura angular ni en el tamaño de la malla entre los 3 grupos, siendo el grosor del iris menor en controles (p = 0,005); identificándose en todos los pacientes el depósito PSX mediante OCT. Conclusiones: No se detectaron diferencias entre las medidas biométricas del segmento anterior entre los pacientes con PSX y controles, salvo en el caso de la densitometría corneal central y el grosor del iris que fueron mayores en el grupo con PSX y en los ojos contralaterales (AU)

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 (AU)

Agreement between Pentacam and optical coherence tomography in the assessment of iridocorneal angle width in a large healthy population.

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.

Pseudoexfoliation signs in the anterior segment assessed by optical coherence tomography and Scheimpflug device. / Evaluación de los signos de la pseudoexfoliación en el segmento anterior mediante tomografía de coherencia óptica y cámara de Scheimpflug.

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.

Identificación de estructuras del ángulo iridocorneal mediante tomografía de coherencia óptica de dominio Fourier / Identification of iridocorneal angle structures assessed by Fourier domain optical coherence tomography

OBJETIVO: Estudiar las estructuras que conforman el ángulo iridocorneal mediante tomografía de coherencia óptica (OCT) de segmento anterior, definiendo sus características tomográficas y cuantificando su frecuencia de identificación. MATERIAL Y MÉTODOS: Estudio transversal realizado en 267 ojos derechos de 267 pacientes consecutivos sanos. Se empleó una OCT de dominio Fourier RTVue (Optovue Inc, CA, EE. UU.) para explorar el ángulo iridocorneal en los sectores nasal y temporal. Las estructuras evaluadas fueron: el limbo externo, transición corneoescleral, línea de Schwalbe, malla trabecular, canal de Schlemm, espolón escleral y receso angular. Se calculó la concordancia intra- e interobservador para la identificación de las estructuras mediante el coeficiente kappa. RESULTADOS: La edad media fue 41,3 ± 14,3 años (rango 20-80); el 57% eran mujeres. El limbo externo, la transición córneo-escleral y la línea de Schwalbe se identificaron en un 98,7; 97 y 93,4%, respectivamente de las imágenes. La malla trabecular y el canal de Schlemm se identificaron en el 91% de los casos. El espolón escleral pudo ser identificado en un 85,4% y el receso angular en un 74,5%. No existió diferencia en la identificación entre el sector temporal y nasal. La concordancia intra- e interobservador fue de k = 0,92 y k = 0,88 respectivamente, en la identificación de las estructuras para el total de las imágenes estudiadas. CONCLUSIONES: La OCT de dominio Fourier es una técnica eficaz para la identificación de las estructuras que conforman el ángulo iridocorneal, entre las que destacan la malla trabecular, el canal de Schlemm, el espolón escleral y la línea de Schwalbe

OBJECTIVE: To study the structures of the iridocorneal angle using anterior segment optical coherence tomography (OCT) defining their tomographic characteristics and quantifying their identification frequency. MATERIAL AND METHODS: A cross-sectional study was performed on 267 right eyes of 267 consecutive healthy patients. Fourier domain OCT RTVue (Optovue Inc, CA, EE. UU.) was used to examine the iridocorneal angle in the nasal and temporal sectors. The structures evaluated were: Sclerocorneal limbus, sclerocorneal transition, Schwalbe's line, trabecular meshwork, Schlemm's canal, scleral spur, and angular recess. Within and between agreements to identify structures were calculated using Cohen's kappa coefficient. RESULTS: The mean age was 41.3 ± 14.3 years (range 20-80), with 57% being women. The sclerocorneal limbus, sclerocorneal transition, and Schwalbe's line were identified by 98.7, 97 and 93.4% of the images, respectively, with the trabecular meshwork and Schlemm's canal being identified in 91% of cases. The scleral spur could be identified in 85.4%, and the angular recess in 74.5%. There was no difference in the identification between the temporal and nasal sectors. Within and between agreement was k = 0.92 and k = 0.88, respectively, in the identification of the structures of the total images studied. CONCLUSIONS: Fourier domain OCT is a reliable technique for the identification of the structures of the iridocorneal angle, among which can be highlighted are, the trabe

Identification of iridocorneal angle structures assessed by Fourier domain optical coherence tomography.

OBJECTIVE: To study the structures of the iridocorneal angle using anterior segment optical coherence tomography (OCT) defining their tomographic characteristics and quantifying their identification frequency. MATERIAL AND METHODS: A cross-sectional study was performed on 267 right eyes of 267 consecutive healthy patients. Fourier domain OCT RTVue (Optovue Inc, CA, EE. UU.) was used to examine the iridocorneal angle in the nasal and temporal sectors. The structures evaluated were: Sclerocorneal limbus, sclerocorneal transition, Schwalbe's line, trabecular meshwork, Schlemm's canal, scleral spur, and angular recess. Within and between agreements to identify structures were calculated using Cohen's kappa coefficient. RESULTS: The mean age was 41.3 ± 14.3 years (range 20-80), with 57% being women. The sclerocorneal limbus, sclerocorneal transition, and Schwalbe's line were identified by 98.7, 97 and 93.4% of the images, respectively, with the trabecular meshwork and Schlemm's canal being identified in 91% of cases. The scleral spur could be identified in 85.4%, and the angular recess in 74.5%. There was no difference in the identification between the temporal and nasal sectors. Within and between agreement was k=0.92 and k=0.88, respectively, in the identification of the structures of the total images studied. CONCLUSIONS: Fourier domain OCT is a reliable technique for the identification of the structures of the iridocorneal angle, among which can be highlighted are, the trabecular meshwork, Schlemm's canal, scleral spur, and Schwalbe's line.