What Are The Risks Of Laser Trabeculoplasty? Who Should Consider LT?

Feb 12, 2015

What Are The Risks Of Laser Trabeculoplasty? Who Should Consider LT?

Laser Trabeculoplasty is usually painless (though not always), fast, and relatively safe. As such, it can be offered to almost anyone with open angle glaucoma at almost any stage in the disease.

Commonly Encountered Complications Associated with LT

As with all surgical procedures, however, there are risks associated with Laser Trabeculoplasty. Following are some of the more commonly encountered complications associated with LT.

Intraocular Pressure Elevation (Spike)

The main risk of all Laser Trabeculoplasty treatments (or any glaucoma laser treatment of the eye for that matter) is a spike in intraocular pressure (IOP). Clearly, when one’s goal is to lower the IOP this is undesirable. Fortunately, these elevations in IOP are generally short-lived. Rarely, however, the IOP will stay elevated which then requires additional non-laser glaucoma surgery for control.[1]

Because of this risk of developing increased eye pressure after LT, many surgeons will treat only half of the trabecular meshwork at the first session. The remaining trabecular meshwork can then be treated, if necessary, at a later date. It is sometimes the case that treatment of only half of the trabecular meshwork is required to achieve IOP lowering.

Scarring of the Eye’s Drainage System (Peripheral Anterior Synechiae)

One notable risk of Argon Laser Trabeculoplasty (ALT) is scarring of the drainage angle and Schlemm’s (drainage) Canal. This scarring is called Peripheral Anterior Synechiae (PAS). It occurs in approximately 12-47% of eyes that have undergone ALT.[2]

Angle scarring had been considered a minor issue as it rarely caused problems other than decreasing the effect of the ALT. Today, however, there are multiple “Minimally Invasive Glaucoma Surgeries” (MIGS) that may not work as well when there is scarring of the angle structures. Fortunately, angle scarring is seen in less than 3% of eyes treated with Selective Laser Trabeculoplasty (SLT).[3]

Because ALT may “close doors” on future MIGS options patients who would benefit from Laser Trabeculoplasty should generally opt for SLT or MLT where available. Of course, there are exceptions, but they are rare.

Rarely encountered additional risks of Laser Trabeculoplasty include corneal damage and swelling of the central retina (macula), both of which could result in loss of vision.

Who Should Consider Laser Trabeculoplasty (LT)?

Most anyone with open angle glaucoma that requires treatment is a candidate for Laser Trabeculoplasty. Although it is generally offered to patients in the USA after drops have been tried (and failed), there is some evidence to suggest that laser trabeculoplasty may work better if it is done prior to drop use. Indeed, multiple studies support the use of laser trabeculoplasty as a reasonable first choice in the treatment of glaucoma.[4]

Certain types of glaucoma seem to respond better to Laser Trabeculoplasty. Pseudoexfoliation glaucoma and pigmentary glaucoma respond particularly well to this treatment.[5]


1) Harasymowycz PJ, Papamatheakis DG, Latina M, et al. Selective laser trabeculoplasty (SLT) complicated by intraocular pressure elevation in eyes with heavily pigmented trabecular meshworks. Am J Ophthalmol. 2005;139:1110-3.

2) Thomas JV, Simmons RJ, Belcher CD 3rd. Argon laser trabeculoplasty in the presurgical glaucoma patient. Ophthalmology. 1982;8 9:187-97.

Traverso CE, Greenidge KC, Spaeth GL. Formation of peripheral anterior synechiae following argon laser trabeculoplasty. A prospective study to determine relationship to position of laser burns. Arch Ophthalmol. 1984;102:861-3.

Rouhiainen HJ, Terasvirta ME, Tuovinen EJ. Peripheral anterior synechiae formation after trabeculoplasty. Arch Ophthalmol. 1988;106:189-91.

3) Wong MOM, Lee JWY, Choy BNK, et al. Systematic review and meta-analysis on the efficacy of selective laser trabeculoplasty in o pen-angle glaucoma. Surv Ophthalmol. 2014[Published online]. 

4) Rosenthal AR, Chaudhuri PR, Chiapella AP. Laser trabeculoplasty primary therapy in open-angle glaucoma. A preliminary report. Arch Ophthalmol. 1984;102(5):699-701.

Thomas JV, El-Mofty A, Hamdy EE, et al. Argon laser trabeculoplasty as initial therapy for glaucoma. Arch Ophthalmol. 1984;102(5):702-703.

Migdal C, Hitching R. Primary therapy for chronic simple glaucoma the role of argon laser trabeculoplasty. Trans Ophthalmol Soc UK. 1985;104(1):62-66.

Sherwood MB, Lattimer J, Hitching RA. Laser trabeculoplasty as supplementary treatment for primary open angle glaucoma. Br J Ophthalmol. 1987;71(3):188-191.

Tuulonen A, Koponen J, Alanko HI, et al. Laser trabeculoplasty versus medication treatment as primary therapy for glaucoma. Acta Ophthalmol. 1989;67(3):275-280.

The Glaucoma Laser Trial Research Group. The Glaucoma Laser Trial (GLT). 2. Results of argon laser trabeculoplasty versus topical medications. Ophthalmology. 1990;97(11):1403-1413.

Elsas T, Johnsen H. Long-term efficacy of primary laser trabeculoplasty. Br J Ophthalmol. 1991;75(1):34-37.

The Glaucoma Laser Trial Research Group. The Glaucoma Laser Trial (GLT) and glaucoma laser trial follow-up study: 7. Results. Am J Ophthalmol. 1995;120(6):718-731.

5) Forbes M, Bansal RK. Argon laser goniophotocoagulation of the trabecular meshwork in open-angle glaucoma. Trans Am Ophthalmol Soc. 1981;79:257-275.

Pohjanpelto P. Argon laser trabeculoplasty of the anterior chamber angle for increased intraocular pressure. Acta Ophthalmol. 1981;59(2):211-220.

Brooks AM, Gillies WE. Do any factors predict a favorable response to laser trabeculoplasty? Aust J Ophthalmol. 1984;12(2):149-153.

Robin AL, Polack IP. Argon laser trabeculoplasty in secondary forms of open-angle glaucoma. Arch Ophthalmol. 1983;101(3):382-384.

Lieberman MF, Hoskins HD Jr, Hetherington J Jr. Laser trabeculoplasty and the glaucomas. Ophthalmology. 1983;90(7):790-795.

Lunde MW. Argon laser trabeculoplasty in pigmentary dispersion syndrome with glaucoma. Am J Ophthalmol. 1983;96(6):721-725.

Ritch R, Liebmann J, Robin A, et al. Argon laser trabeculoplasty in pigmentary glaucoma. Ophthalmology. 1993;100(6):909-913.

Don’t delay getting checked for glaucoma.

Make an appointment with an eye doctor in your area now.  If you live in the greater Los Angeles area and would like Dr. Richardson to evaluate your eyes for glaucoma call 626-289-7856 now. No referral required. Appointments are available, Tuesday through Saturday.

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