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Effectiveness of laser peripheral iridoplasty in the treatment of acute primary angle closure

Wirksamkeit der peripheren Iridoplastik mittels Laser zur Behandlung des akuten primären Winkelverschlusses



Acute primary-angle closure (APAC) is a common condition in Asian populations due to pupillary block and anterior chamber angle closure. Argon laser peripheral iridoplasty (ALPI) involves laser impacts, the thermal effect of which is to retract the periphery of the iris, subsequently widening the iridocorneal angle and facilitating drainage.


To evaluate the effectiveness and safety of ALPI as a treatment for APAC.

Patients and methods

An uncontrolled, interventional and prospective study was conducted including 26 eyes of 24 patients with APAC treated by ALPI at the Vietnam National Eye Hospital from December 2019 to August 2020. Intraocular pressure (IOP) before and after ALPI, visual acuity, cornea, pupil, and irido-cornea angle were analyzed. Angle width in Shaffer grades was assessed. Angle configuration was also evaluated using angle opening distance (AOD500), trabecular-iris angle (TIA) measured in UBM images.


The mean IOP before ALPI of the group decreased from 44.8 ± 9.0 mm Hg to 27.6 ± 8.4 mm Hg at 15 min, 21.4 ± 8.7 mm Hg at 30 min, 16.5 ± 8.9 mm Hg at 60 min, and 13.1 ± 9.1 mm Hg at 120 min after the procedure. Before treatment, almost affected eyes had closed angles or very narrow angles. After the treatment, there was an increase in the angle width, and the mean TIA increased from 0.13 ± 0.68° to 17.2 ± 12.3°; the mean AOD500 increased from 0.5 ± 2 μm to 123.9 ± 92.5 μm (p < 0.001). One eye had a peripheral corneal burn.


It appears that ALPI is effective and safe in controlling IOP in acute primary-angle closure.



Der akute primäre Winkelverschluss ist eine häufige Erkrankung in asiatischen Populationen aufgrund eines Pupillenblocks und Verschlusses des Vorderkammerwinkels. Durch die periphere Iridoplastik mittels Argonlaser kommt es zu Lasereinwirkungen, deren thermischer Effekt darin besteht, die Peripherie der Iris zurückzuziehen, wodurch der Iris-Hornhaut-Winkel erweitert und die Drainage erleichtert wird.


Ziel war die Bewertung der Wirksamkeit und Sicherheit der peripheren Iridoplastik mit einem Argonlaser als Behandlung für einen akuten primären Winkelverschluss.

Patienten und Methoden

Es handelt sich um eine unkontrollierte, interventionelle und prospektive Studie, in der 26 Augen von 24 Patienten mit akutem primärem Winkelverschluss von Dezember 2019 bis August 2020 mittels peripherer Iridoplastik mit einem Argonlaser im Vietnam National Eye Hospital behandelt wurden. Augeninnendruck vor und nach peripherer Iridoplastik mittels Argonlaser, Sehschärfe, Hornhaut, Pupille und Iris-Hornhaut-Winkel wurden analysiert. Die Weite des Winkels wurde nach Shaffer in Grad gemessen. Die Winkelkonfiguration wurde auch anhand der Winkelöffnungsstrecke (AOD500) und des Trabekel-Iris-Winkels bewertet, die in Ultraschall-Biomikroskopie(UBM)-Bildern gemessen wurden.


Der mittlere Augeninnendruck vor der peripheren Iridoplastik mittels Argonlaser in dieser Gruppe sank von 44,8 ± 9,0 mm Hg auf 27,6 ± 8,4 mm Hg nach 15 min; 21,4 ± 8,7 mm Hg nach 30 min; 16,5 ± 8,9 mm Hg nach 60 min und 13,1 ± 9,1 mm Hg nach 120 min nach Anwendung des Verfahrens. Vor der Behandlung hatten fast betroffene Augen geschlossene oder sehr enge Winkel. Nach der Behandlung nahm die Winkelweite zu, der mittlere Trabekel-Iris-Winkel stieg von 0,13 ± 0,68 Grad auf 17,2 ± 12,3 Grad; der mittlere AOD500 stieg von 0,5 ± 2 µm auf 123,9 ± 92,5 µm (p < 0,001). Ein Auge wies eine periphere Hornhautverbrennung auf.


Die periphere Iridoplastik mit dem Argonlaser schien wirksam und sicher bei der Kontrolle des Augeninnendrucks bei akutem primärem Winkelverschluss zu sein.

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Anterior chamber depth


Argon laser peripheral iridoplasty


Angle opening distance at 500 μm from the scleral spur


Acute primary-angle closure


Intraocular pressure


Trabecular-iris angle


Ultrasound biomicroscopy


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We thank Vietnam National Eye Hospital, Hanoi, Vietnam and Hanoi Medical University, Hanoi, Vietnam for supporting this study.

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Correspondence to Anh Tuan Vu MD, PhD.

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Conflict of interest

A. T. Vu, T. V. A. Bui, L. A. Mai, T. T. Hoang and L. T. Nguyen declare that they have no competing interests.

Ethical standards

All procedures performed in studies involving human participants or on human tissue were in accordance with the ethical standards of the institutional and/or national research committee (Ethical Review Committee of the Hanoi Medical University, Vietnam) and with the 1975 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study.

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Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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Vu, A.T., Bui, T.V.A., Mai, L.A. et al. Effectiveness of laser peripheral iridoplasty in the treatment of acute primary angle closure. Spektrum Augenheilkd. (2022).

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  • Acute primary angle closure (APAC)
  • Argon laser peripheral iridoplasty (ALPI)
  • Iridoplasty
  • Gonioplasty


  • Akuter primärer Winkelverschluss
  • Periphere Iridoplastik mit Argonlaser
  • Iridoplastik
  • Gonioplastik