Laser iridotomy is the basic procedure in the treatment of glaucoma. The patient must be properly qualified for such a procedure, which is possible only after performing thorough and comprehensive specialist examinations. What are the indications and contraindications for laser iridotomy? How does this procedure work?
Laser iridotomyis designed to widen the angle and allow the aqueous humor to reach the trabecular and further drainage routes from the eye. The indications for this procedure are primary angle-closure glaucoma or an ophthalmologically confirmed narrow angle of the anterior chamber with a high risk of closure. Laser iridotomy is also performed in some cases of pigmentary glaucoma, where the angle is open, but the aim of the procedure is to flatten the base of the iris and reduce its contact with the ciliary rim, which reduces the amount of dye pouring out. Contraindications for laser iridotomy are the lack of access to the anterior chamber due to corneal haze or a high degree of shallowing of the anterior chamber, which may make the procedure technically difficult. However, these difficulties must be considered individually for a specific patient, because sometimes, despite the occurrence of such difficulties, iridotomy is the best treatment method, e.g. in the case of acute closure of the anterior chamber angle, the performance of this procedure may stop the glaucoma attack and protect the optic nerve from damage.
What is laser iridotomy?
The laser iridotomy procedure is not painful, but requires a special contact lens with the use of a special gel on the eye. Before the procedure, the doctor narrows the pupil with 2% Pilocarpine in the form of drops and gives the patient local anesthesia, also in the form of eye drops. As a prevention of an increase in intraocular pressure, 1% apraclonidine should be administered one hour before the procedure, as well as immediately after the procedure. It is also recommended to administer orally 500 mg acetazolamide before the procedure. The procedure involves making a small hole around the circumference of the iris, most often in its upper quadrants, under the eyelid, with the help of a laser beam. As a result, the hole is invisible and does not cause visual disturbances. The purpose of the procedure is to obtain an openingcovering the full thickness of the iris and sufficient diameter to unblock the pupil. It is assumed that the perforation of the iris occurs when the dye mixed with the aqueous fluid enters the anterior chamber and the iris retracts, which will deepen the anterior chamber around its perimeter. Before the procedure, the patient must be informed about possible side effects and complications of the procedure, and must give written consent to this procedure and confirmation that he is aware of the risks it entails.
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Possible complications and what to do after the procedure
The most common complications after laser iridotomy are bleeding from the iris during the procedure, a temporary increase in intraocular pressure after the procedure, inflammation inside the eyeball that may cause posterior adhesions, damage to the corneal epithelium. Rare complications include damage to the corneal endothelium, lens clouding, macular edema.
The patient should be inspected three hours after the procedure, and then on the first and second day. It is necessary to evaluate the patency of the iridotomy because if it is not clear, the procedure is not effective. An excellent method of imaging iridotomy and its patency is the examination of optical coherence tomography of the anterior segment - AS-OCT or UBM ultrabiomicroscopy. It is also important to assess the degree of angle opening after the procedure. At present, each patient after laser iridotomy should undergo diagnostic tests confirming the effectiveness of the procedure.
About the authorBarbara Polaczek-Krupa, MD, PhD, specialist in eye diseases, Centrum Opulystowa Targowa 2, WarsawDr. Barbara Polaczek-Krupa, MD, initiator and founder of the T2 Center. She specializes in modern diagnostics and treatment of glaucoma - this was also the subject of her PhD thesis defended with honors in 2010.
Dr. med. Polaczek-Krupa has been gaining experience for 22 years, since she started working at the Ophthalmology Clinic of CMKP in Warsaw, with which she was associated in 1994-2014. During this period, she obtained two degrees of specialization in ophthalmology and the title of doctor of medical sciences.
In the years 2002-2016 she worked at the Institute of Glaucoma and Eye Diseases in Warsaw, where she gained knowledge and medical experience by consulting patients from all over Poland and abroad.
For years, as part of cooperation with the Medical Center of Postgraduate Education, he has been a lecturer at courses and trainings for doctors specializing in ophthalmology and primary he alth care.
He is the author or co-author of numerous publications inscientific journals. Member of the Polish Ophthalmology Society (PTO) and the European Glaucoma Society (EGS).
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