Swept-source optical coherence tomography detects anterior-chamber changes in patients with angle-closure after laser peripheral iridotomy / Tomografia de coerência óptica swept-source detecta alterações na câmara anterior em pacientes com fechamento angular após iridotomia

ABSTRACT Purpose: This study aimed to compare an teriorchamber parameters acquired by a swept-source anteriorsegment optical coherence tomography before and after laser peripheral iridotomy. Methods: This study prospectively evaluated 14 patients with primary-angle closure and six patients with primary-angle closure glaucoma. Gonioscopy and anterior-segment optical coherence tomography using the DRI OCT Triton® were performed before and after laser peripheral iridotomy. Anterior-segment optical coherence tomography parameters were studied using scleral spur as reference: angle opening distance at 250, 500, and 750 µm, trabecular-iris space at 500 µm, trabecular-iris angle, trabecular-iris contact length, and iris curvature. Results: Anterior-segment optical coherence tomography identified 61% of the patients with two or more quadrants closed. Gonioscopy identified more closed angles than anterior-segment optical coherence tomography before laser peripheral iridotomy. In angle parameters, only the angle opening distance of 250 µm at the nasal quadrant was not significantly increased after laser peripheral iridotomy. The iris curvature and trabecular-iris contact length showed a significant reduction induced by the laser procedure. Even in eyes in which gonioscopy did not identify angular widening after laser peripheral iridotomy (n=7), the angle opening distance of 750 µm increased (nasal, 0.15 ± 0.10 mm to 0.27 ± 0.16 mm, p=0.01; temporal, 0.14 ± 0.11 mm to 0.25 ± 0.12 mm, p=0.001) and the iris curvature decreased (nasal, 0.25 ± 0.04 mm vs. 0.11 ± 0.07 mm, p=0.02; temporal, 0.25 ± 0.07 mm vs. 0.14 ± 0.08 mm, p=0.007). Conclusions: Anterior-chamber changes induced by laser peripheral iridotomy could be quantitatively evaluated and documented by DRI OCT Triton®

RESUMO Objetivo: Comparar os parâmetros de câmara anterior obtidos através da tomografia de coerência óptica de segmento anterior antes e após a iridectomia periférica a laser. Métodos: Quatorze pacientes com fechamento angular primário e seis com glaucoma primário de ângulo fechado foram prospectivamente avaliados neste estudo. Gonioscopia e tomografia de coerência óptica de segmento anterior com DRI OCT Triton® foram realizadas antes e após a iridectomia periférica a laser. Os seguintes parâmetros de tomografia de coerência óptica de segmento anterior, baseados na localização do esporão escleral, foram avaliados: ângulo de abertura angular a 250 µm, 500 µm e 750 µm, área do espaço entre a íris e o trabeculado a 500 µm, ângulo entre a íris e o trabeculado, extensão do contato entre a íris e o trabeculado e curvatura da íris. Resultados: A tomografia de coerência óptica de segmento anterior identificou 61% dos indivíduos com dois ou mais quadrantes fechados. A gonioscopia identificou mais quadrantes com ângulo fechado do que tomografia de coerência óptica de segmento anterior antes da iridectomia periférica a laser. Quanto aos parâmetros angulares, apenas ângulo de abertura angular a 250 µm no quadrante nasal não aumentou significativamente após a iridectomia periférica a laser. A curvatura da íris e a extensão do contato entre a íris e o trabeculado apresentaram redução significativa induzida pelo procedimento a laser. Mesmo nos olhos em que a gonioscopia não identificou aumento da amplitude angular após iridectomia periférica a laser (n=7), ângulo de abertura angular a 750 µm aumentou (nasal: 0,15 ± 0,10 mm para 0,27 ± 0,16 mm, p=0,01; temporal: 0,14 ± 0,11 mm para 0,25 ± 0,12 mm, p=0,001), e ICURVE diminuiu (nasal: 0,25 ± 0,04 mm vs. 0,11 ± 0,07 mm, p=0,02; temporal: 0,25 ± 0,07 mm vs. 0,14 ± 0,08 mm, p=0,007). Conclusões: As alterações na câmara anterior induzidas pelo iridectomia periférica a laser puderam ser avaliadas quantitativamente e documentadas pelo DRI OCT Triton®.

Swept-source optical coherence tomography detects anterior-chamber changes in patients with angle-closure after laser peripheral iridotomy.

PURPOSE: This study aimed to compare an teriorchamber parameters acquired by a swept-source anteriorsegment optical coherence tomography before and after laser peripheral iridotomy. METHODS: This study prospectively evaluated 14 patients with primary-angle closure and six patients with primary-angle closure glaucoma. Gonioscopy and anterior-segment optical coherence tomography using the DRI OCT Triton® were performed before and after laser peripheral iridotomy. Anterior-segment optical coherence tomography parameters were studied using scleral spur as reference: angle opening distance at 250, 500, and 750 µm, trabecular-iris space at 500 µm, trabecular-iris angle, trabecular-iris contact length, and iris curvature. RESULTS: Anterior-segment optical coherence tomography identified 61% of the patients with two or more quadrants closed. Gonioscopy identified more closed angles than anterior-segment optical coherence tomography before laser peripheral iridotomy. In angle parameters, only the angle opening distance of 250 µm at the nasal quadrant was not significantly increased after laser peripheral iridotomy. The iris curvature and trabecular-iris contact length showed a significant reduction induced by the laser procedure. Even in eyes in which gonioscopy did not identify angular widening after laser peripheral iridotomy (n=7), the angle opening distance of 750 µm increased (nasal, 0.15 ± 0.10 mm to 0.27 ± 0.16 mm, p=0.01; temporal, 0.14 ± 0.11 mm to 0.25 ± 0.12 mm, p=0.001) and the iris curvature decreased (nasal, 0.25 ± 0.04 mm vs. 0.11 ± 0.07 mm, p=0.02; temporal, 0.25 ± 0.07 mm vs. 0.14 ± 0.08 mm, p=0.007). CONCLUSIONS: Anterior-chamber changes induced by laser peripheral iridotomy could be quantitatively evaluated and documented by DRI OCT Triton®.

Diagnostic Performance of Optical Coherence Tomography and Nonspecialist Gonioscopy to Detect Angle Closure.

Aim: To compare the usefulness of gonioscopy performed by general ophthalmologists (GO) and anterior segment optical coherence tomography (AS-OCT) in detecting angle closure in patients with a shallow anterior chamber. Methods: Forty-four patients with a shallow anterior chamber (defined by a ratio of peripheral anterior chamber depth to peripheral corneal thickness lower than 1/2) were included in this cross-sectional study. Gonioscopy was performed in all subjects by two glaucoma experts (GE1 and GE2) and one GO. Anterior segment imaging was performed using Visante® OCT (Carl Zeiss Meditec Inc.). Agreement between examiners was assessed with first-order agreement coefficients (AC1). Diagnostic accuracies of GO gonioscopy and AS-OCT were evaluated using sensitivity, specificity, and area under the receiver operating characteristic (AROC) curves. Results: For static gonioscopy, the agreement between GE1 and GE2 was substantial (AC1 = 0.65), and that between GE1 and GO was moderate (AC1 = 0.50). For indentation gonioscopy, the agreement between GE1 and GE2 was slightly lower (AC1 = 0.55); however, the agreement between GE1 and GO showed a larger reduction (AC1 = 0.12). GO's gonioscopy presented a low specificity (25%) and the AROC to angle closure detection was lower than AS-OCT (0.56-0.73). Combined information of GO gonioscopy and AS-OCT improved specificity (85.7%) and AROC (0.77) of angle closure evaluation. Conclusion: Agreement between GO and glaucoma experts was moderate for static gonioscopy and slight for indentation gonioscopy. AS-OCT performed better than GO gonioscopy in detecting angle closure in patients with a shallow anterior chamber. The addition of AS-OCT to clinical information in patients with GO positive gonioscopy improved the specificity and AROC of gonioscopy test. How to cite this article: Esporcatte BLB, Vessani RM, Melo Jr LAS, et al. Diagnostic Performance of Optical Coherence Tomography and Nonspecialist Gonioscopy to Detect Angle Closure. J Curr Glaucoma Pract 2022;16(1):53-58.