3Laser trabeculoplasty In the early 1970s attempts were made to use argon laser energy to puncture through TM into Schlemm,s canal, which was unsuccesful.In 1979, Wise and Witter used non-penetrating laser energy in the TM and found that they were able to lower IOP for a prolonged period.
4Mechanism It is not entirely clear. Thinning and scarring of the TM at the site of laser treatment.The spaces between the laser spots are widened and free of debris.The initial theory is that a mechanical tightening of the terabecular ring increased aqueous outflow.
5Indications for laser terabeculoplasty Effective in the treatment of the following:1- primary open-angle glaucoma2- exfoliative glaucoma3- pigmentary glaucoma
6Less effective in the treatment of the following Aphakic eyesPseudophakic eyes
7Unlikely to be effective in the treatment of the following Angle-recession glaucomaInflammatory glaucomaCongenital/developmental glaucomaJuvenile glaucoma
8Not possible in the treatment of the following Synechial angle closure such as:Neovascular glaucoma and ICE syndrome
9Technique of laser terabeculoplasty Wavelength :Argon green or blue-greenSpot size: 50 micronDuration: 0.1 secondPower: mWApplications: spots per 180 degree or spots / 360 degreeLens: Goldmann 3-mirror or equivalent
10General considerations In lightly pigmented angles a beginning power of mw is reasonable.In heavily pigmented angles, lower powers such as mw should be used.Postoperative IOP spikes are especially worrisome in patients with marked angle pigmentation or advanced optic nerve head damage.
11The aiming beam should be directed at the junction between the pigmented and non-pigmented TM. Patients are usually seen 1 or 2 hours after the LTP to ensure that no postoperative IOP rise has occurred.Topical corticosteroids should be used 4 times a day for 4 days in addition to the preexisting glaucoma medications.
12The typical tissue response to LTP is a blanching of the TM, often associated with a small gas bubble.The bubbles are transient, but the blanching may persist for several days.
16Laser peripheral iridotomy LPI was first introduced in 1956, but it become popularized with the advent of the argon laser and more recently the Nd:YAGThis technology has almost totally replaced surgical iridectomy.
17Indications Acute angle closure glaucoma Secondary pupillary block due to any reason.LPI is not helpful for synechial angle closure caused by neovascularization, ICE syndrome.LPI is used for patients at risk for developing angle closure.
18TechniqueTo lower the IOP in case of acute angle closure glaucoma by medication.Supranasal area is prefered.The depth of an iris crypt is a proper position.
19Argon laser peripheral iridotomy Spot size: 50 micronDuration: secondPower: 1 WLens: Abraham or Wise
24Postoperative management A drop of a2-adrenergic agonist.The IOP checking 1-2 hours later.Prednisolone 4 times a day for 4 days.Preoperative glaucoma medications are to be continued.Pilocarpine should be avoided.
25Complications Transient iritis is the most complication. IOP elevation is common.Occasionally corneal epithelial opacities.Lens epithelial changes.Bleeding of the iris is a frequent complication.Monocular diplopia (rarely)
26Laser iridoplastyLaser iridoplasty is performed on patients with plateau iris syndrome.It can be used before LTP to provide better view of the iridocorneal angle.4 to 6 applications are applied per quadrant.
29A common problem in glaucoma patients who have been on chronic miotic therapy is a markedly constricted pupil.This is especially a problem in a patient with early cataract formation.It may be possible to improve their vision by dilating the pupil with laser pupilloplasty.
30This procedure involves the application of low energy, contraction burns in several radial row around the pupil.Standard setting are 0.2 to 0.5 second, 200 to 500 microns, and 200 to 500 mw.Postoperative complications include IOP rise and transient iritis.
31ضمن عرض پوزشبدلیل حجم بالای LECTUER ادامه اسلایدها امکان پذیر نمیباشد در صورت نیاز به ادامه لطفا به واحد سمعی و بصری مرکز آموزشی درمانی فیض مراجعه و یا با شماره تلفن داخلی 392 تماس حاصل نمائیدبا تشکر