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Peripheral anterior synechiae and ultrasound biomicroscopic parameters in angle-closure glaucoma suspects.

Yoo C, Oh JH, Kim YY, Jung HR - Korean J Ophthalmol (2007)

Bottom Line: The AOD(500), ARA, and TIA were not significantly different between the eyes with PAS (9 eyes) and without PAS (18 eyes) at each quadrant.However, the TCPD was significantly shorter in the superior quadrant when compared with the eyes without PAS (mean: 405.3+/-70.9 microm vs 536.4+/-140.5 microm) (p<0.05).The results suggest that the shorter distance from trabecular meshwork to ciliary body or the anterior placement of ciliary process may play a role in the development of PAS in ACGS eyes.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.

ABSTRACT

Purpose: To investigate the correlation between peripheral anterior synechia (PAS) and the quantitative anterior chamber angle parameters measured by ultrasound microscopy (UBM) in angle-closure glaucoma suspect (ACGS) eyes.

Methods: Eyes were defined ACGS as having occludable angles and intraocular pressure less than 21 mm Hg without glaucomatous optic nerve head. The gonioscopic criteria for ACGS were the trabecular meshwork invisible in 3 or more quadrants of the entire angle and the angular width less than 20 degrees by Shaffer classification. Twenty-seven eyes of 20 patients underwent anterior chamber angle and ciliary body imaging with UBM. Angle opening distance (AOD(500)), angle recess area (ARA), trabecular-ciliary process distance (TCPD) and trabecular-iris angle (TIA) were measured from the UBM images at each quadrant.

Results: The AOD(500), ARA, and TIA were not significantly different between the eyes with PAS (9 eyes) and without PAS (18 eyes) at each quadrant. However, the TCPD was significantly shorter in the superior quadrant when compared with the eyes without PAS (mean: 405.3+/-70.9 microm vs 536.4+/-140.5 microm) (p<0.05).

Conclusions: The results suggest that the shorter distance from trabecular meshwork to ciliary body or the anterior placement of ciliary process may play a role in the development of PAS in ACGS eyes.

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Related in: MedlinePlus

Schematic representation of UBM anterior chamber angle measurement. Angle opening distance (AOD500) is defined as the length of the line drawn from the point on the corneal endothelial surface 500 µm anterior to the scleral spur to the iris surface perpendicular to the corneal endothelial surface. Trabecular-iris angle (TIA) is defined as an angle formed with the apex at the iris recess and the arms passing through the point on the meshwork 500 µm from the scleral spur and the point on the iris perpendicularly opposite. Trabecular ciliary process distance (TCPD) is defined as the distance between a point 500 µm from the scleral spur and the ciliary process on the line that is perpendicular through the iris. Angle recess area (ARA) is defined as the triangular area bordered by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn to the iris surface from a point 750 µm anterior to the scleral spur.
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Figure 1: Schematic representation of UBM anterior chamber angle measurement. Angle opening distance (AOD500) is defined as the length of the line drawn from the point on the corneal endothelial surface 500 µm anterior to the scleral spur to the iris surface perpendicular to the corneal endothelial surface. Trabecular-iris angle (TIA) is defined as an angle formed with the apex at the iris recess and the arms passing through the point on the meshwork 500 µm from the scleral spur and the point on the iris perpendicularly opposite. Trabecular ciliary process distance (TCPD) is defined as the distance between a point 500 µm from the scleral spur and the ciliary process on the line that is perpendicular through the iris. Angle recess area (ARA) is defined as the triangular area bordered by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn to the iris surface from a point 750 µm anterior to the scleral spur.

Mentions: Under topical anesthesia, a plastic saline-containing eye-cup was used to separate the eyelids. Radial scans of 12, 3, 6 and 9 o'clock positions and an axial scan were performed under standard room illumination. UBM examination was performed with the patient lying supine. Five parameters were measured with UBM according to the Pavlin et al's method.9-11 Figure 1 shows a schematic representation of the UBM measurements. Anterior chamber depth (ACD) indicates the distance between the endothelium and the anterior surface of the lens along the visual axis. Angle opening distance (AOD500) corresponds to the distance between the trabecular meshwork and the iris at 500 µm anterior to the scleral spur. Trabecular iris angle (TIA) is defined as an angle formed with the apex at the iris recess and the arms passing through the point on the meshwork 500 µm from the scleral spur and the point on the iris perpendicularly opposite. Trabecular ciliary process distance (TCPD) indicates the distance between the trabecular meshwork and the ciliary process at 500 µm anterior to the scleral spur. Angle recess area (ARA) represents the triangular area bordered by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn to the iris surface from a point 750 µm anterior to the scleral spur. All these quantitative measurements were performed by a single well-trained operator (JHO).


Peripheral anterior synechiae and ultrasound biomicroscopic parameters in angle-closure glaucoma suspects.

Yoo C, Oh JH, Kim YY, Jung HR - Korean J Ophthalmol (2007)

Schematic representation of UBM anterior chamber angle measurement. Angle opening distance (AOD500) is defined as the length of the line drawn from the point on the corneal endothelial surface 500 µm anterior to the scleral spur to the iris surface perpendicular to the corneal endothelial surface. Trabecular-iris angle (TIA) is defined as an angle formed with the apex at the iris recess and the arms passing through the point on the meshwork 500 µm from the scleral spur and the point on the iris perpendicularly opposite. Trabecular ciliary process distance (TCPD) is defined as the distance between a point 500 µm from the scleral spur and the ciliary process on the line that is perpendicular through the iris. Angle recess area (ARA) is defined as the triangular area bordered by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn to the iris surface from a point 750 µm anterior to the scleral spur.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2629701&req=5

Figure 1: Schematic representation of UBM anterior chamber angle measurement. Angle opening distance (AOD500) is defined as the length of the line drawn from the point on the corneal endothelial surface 500 µm anterior to the scleral spur to the iris surface perpendicular to the corneal endothelial surface. Trabecular-iris angle (TIA) is defined as an angle formed with the apex at the iris recess and the arms passing through the point on the meshwork 500 µm from the scleral spur and the point on the iris perpendicularly opposite. Trabecular ciliary process distance (TCPD) is defined as the distance between a point 500 µm from the scleral spur and the ciliary process on the line that is perpendicular through the iris. Angle recess area (ARA) is defined as the triangular area bordered by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn to the iris surface from a point 750 µm anterior to the scleral spur.
Mentions: Under topical anesthesia, a plastic saline-containing eye-cup was used to separate the eyelids. Radial scans of 12, 3, 6 and 9 o'clock positions and an axial scan were performed under standard room illumination. UBM examination was performed with the patient lying supine. Five parameters were measured with UBM according to the Pavlin et al's method.9-11 Figure 1 shows a schematic representation of the UBM measurements. Anterior chamber depth (ACD) indicates the distance between the endothelium and the anterior surface of the lens along the visual axis. Angle opening distance (AOD500) corresponds to the distance between the trabecular meshwork and the iris at 500 µm anterior to the scleral spur. Trabecular iris angle (TIA) is defined as an angle formed with the apex at the iris recess and the arms passing through the point on the meshwork 500 µm from the scleral spur and the point on the iris perpendicularly opposite. Trabecular ciliary process distance (TCPD) indicates the distance between the trabecular meshwork and the ciliary process at 500 µm anterior to the scleral spur. Angle recess area (ARA) represents the triangular area bordered by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn to the iris surface from a point 750 µm anterior to the scleral spur. All these quantitative measurements were performed by a single well-trained operator (JHO).

Bottom Line: The AOD(500), ARA, and TIA were not significantly different between the eyes with PAS (9 eyes) and without PAS (18 eyes) at each quadrant.However, the TCPD was significantly shorter in the superior quadrant when compared with the eyes without PAS (mean: 405.3+/-70.9 microm vs 536.4+/-140.5 microm) (p<0.05).The results suggest that the shorter distance from trabecular meshwork to ciliary body or the anterior placement of ciliary process may play a role in the development of PAS in ACGS eyes.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.

ABSTRACT

Purpose: To investigate the correlation between peripheral anterior synechia (PAS) and the quantitative anterior chamber angle parameters measured by ultrasound microscopy (UBM) in angle-closure glaucoma suspect (ACGS) eyes.

Methods: Eyes were defined ACGS as having occludable angles and intraocular pressure less than 21 mm Hg without glaucomatous optic nerve head. The gonioscopic criteria for ACGS were the trabecular meshwork invisible in 3 or more quadrants of the entire angle and the angular width less than 20 degrees by Shaffer classification. Twenty-seven eyes of 20 patients underwent anterior chamber angle and ciliary body imaging with UBM. Angle opening distance (AOD(500)), angle recess area (ARA), trabecular-ciliary process distance (TCPD) and trabecular-iris angle (TIA) were measured from the UBM images at each quadrant.

Results: The AOD(500), ARA, and TIA were not significantly different between the eyes with PAS (9 eyes) and without PAS (18 eyes) at each quadrant. However, the TCPD was significantly shorter in the superior quadrant when compared with the eyes without PAS (mean: 405.3+/-70.9 microm vs 536.4+/-140.5 microm) (p<0.05).

Conclusions: The results suggest that the shorter distance from trabecular meshwork to ciliary body or the anterior placement of ciliary process may play a role in the development of PAS in ACGS eyes.

Show MeSH
Related in: MedlinePlus