This page was enrolled in the International Ophthalmologists contest. The first report of an effective surgical treatment for glaucoma was made in by the German ophthalmologist Albrecht von Graefe, who described the execution of a broad-sector surgical iridectomy through a corneal wound. However, since the emergence of laser technology in the field of ophthalmology, laser peripheral iridotomy LPI has largely surpassed the former technique. Laser peripheral iridotomy LPI is indicated to prevent or overcome a suspected relative pupillary block by creating an alternative pathway for aqueous flow. Mainly used for patients in the primary angle closure spectrum, it can also be useful in secondary angle closure glaucoma and in the management of other types of glaucoma with associated pupillary block.
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Nd:YAG neodymium: yttrium—aluminium—garnet laser iridotomy is challenging in the heavily pigmented irides of African and Asian patients,. To present a modified laser iridotomy technique for use in dark irides. The combined technique avoids common issues associated with the use of pure YAG laser, including high energy levels and a high risk of iris haemorrhage.
The technique is more effective and has reduced complications in comparison to pure argon or YAG laser techniques. In addition, the technique was more difficult in eyes of African patients in whom the irides were often thicker and more heavily pigmented. Before laser treatment all patients underwent ophthalmic evaluation, and informed consent was obtained. A drop of 0. The superior iris was assessed, and where possible an iris crypt selected.
The argon laser was applied in two stages. Minor iris haemorrhage was identified in three eyes and was stopped by light pressure with the Abraham contact lens.
The argon laser photocoagulates tissues, absorption by iris pigment results in heating, the coagulation of blood and collagen, with shrinking and charring of tissue. During the s, the YAG laser was introduced.
The YAG laser photodisrupted tissues, focal nanosecond pulses stripped electrons from atoms within the iris, and generated a plasma that rapidly expanded and collapsed, which created a shock wave at the site of focus. Sequential argon—YAG laser was proposed for use in the dark irides of Chinese patients.
Subsequent YAG laser in the area of iris thinning is efficient, using only a third of the corresponding power reported for pure YAG laser iridotomy. In addition, the morphology of the iridotomy is often large and round, in contrast with the slit opening of YAG iridotomy.
Although the combined argon—YAG laser iridotomy required the use of two lasers, the technique is effective with a single sitting. These bubbles are of sufficient size to obscure the underlying iris; although tapping the Abraham lens may dislodge them, this may considerably prolong the procedure.
Small vapour bubbles may be formed; however, shooting the laser at the edge of these small vapour bubbles released them from the iris surface. We found the combined argon—YAG yttrium—aluminium—garnet laser iridotomy technique to have advantages over conventional pure YAG and argon laser. Minor iris haemorrhage could be stemmed by gentle digital pressure on the Abraham contact lens; no procedure required postponing or treatment at an alternative site.
The combined laser offers advantages over conventional pure YAG or argon laser treatments, including a marked reduction in total YAG energy, reduced risk of iris haemorrhage and high patency after primary treatment. Competing interests: None.
National Center for Biotechnology Information , U. Journal List Br J Ophthalmol v. Br J Ophthalmol. Author information Article notes Copyright and License information Disclaimer. Accepted Sep This article has been cited by other articles in PMC. Aim To present a modified laser iridotomy technique for use in dark irides.
Results 15 eyes of 8 consecutive patients who underwent successful combined argon—YAG laser iridotomy using low levels of YAG energy in dark irides is presented. Method Before laser treatment all patients underwent ophthalmic evaluation, and informed consent was obtained. Open in a separate window. Footnotes Competing interests: None.
References 1. Laser iridotomies in Asian eyes. Ann Acad Med Singapore 23 49— Ophthalmology 85 — Ho T, Fan R. Br J Ophthalmol 76 — Ritch R. Techniques of argon laser iridectomy and iridoplasty. Fleck B W. How large must an iridotomy be? Br J Ophthalmol 74 — Quigley H A. Ophthalmology 88 — A comparison of neodymium: YAG and argon laser iridotomies. Ophthalmology 91 — Berger B B. Foveal photocoagulation from laser iridotomy. Bongard B, Pederson J E. Retinal burns from experimental laser iridotomy.
Ophthalmic Surg 16 42— Kielkopf J F. Lasers Surg Med 15 32— Neodymium: YAG and argon laser iridotomy. Ophthalmology 95 — A controlled study comparing argon and neodymium: YAG, Ophthalmology 93 20— Eye 5 Pt 3 — Am J Ophthalmol 41— Br J Ophthalmol 69 77— Corneal endothelial damage with neodymium:YAG laser. Ophthalmic Surg Lasers 31 — Ophthalmic Surg Lasers 26 — Corneal decompensation after argon laser iridectomy—a delayed complication.
Laser iridotomy for glaucoma
Management of intermittent angle closure glaucoma with Nd: yag laser iridotomy as a primary procedure. To assess the efficacy and complications of Nd: YAG laser iridotomy in patients with intermittent sub-acute angle closure glaucoma. Twenty-five eyes of twenty-three patients with periodic intermittent angle closure, selected in outpatient department, were kept on pilocarpine until YAG laser iridotomy was performed. After YAG laser iridotomy oral acetazolamide and topical dexamethasone was used to control post laser rise of IOP and inflammation respectively. Patency of iridotomy was confirmed and intra-ocular pressure was measured one hour after the procedure. Immediate complication, if any, was noted. Follow-up was done for six months.
An iridectomy , also known as a surgical iridectomy or corectomy ,  is the surgical removal of part of the iris. In acute angle-closure glaucoma cases, surgical iridectomy has been superseded by Nd:YAG laser iridotomy, because the laser procedure is much safer. Opening the globe for a surgical iridectomy in a patient with high intraocular pressure greatly increases the risk of suprachoroidal hemorrhage , with potential for associated expulsive hemorrhage. Nd:YAG laser iridotomy avoids such a catastrophe by using a laser to create a hole in the iris, which facilitates flow of aqueous humor from the posterior to the anterior chamber of the eye. From Wikipedia, the free encyclopedia.