Long-term efficacy of argon laser trabeculoplasty. A 10-year follow-up study.

PURPOSE: Argon laser trabeculoplasty (ALT) is commonly used in the treatment of open-angle glaucoma. Varying success rates in lowering intraocular pressure (IOP) and controlling glaucoma are reported in studies with follow-up periods from 1 to 5 years, and few reports are available with follow-up to 10 years. The authors retrospectively reviewed the efficacy of ALT in patients followed up to 10 years. METHODS: Ninety-three patients with open-angle glaucoma underwent 360 degrees ALT. Mean follow-up was 52 +/- 43 months (mean +/- standard deviation; range, 1-132 months). Successful treatment at the time of final follow-up was defined as a decrease in IOP of 3 mmHg or greater from pretreatment level, IOP of 19 mmHg or less, stable visual field, stable optic nerve, and no further laser or surgical intervention. RESULTS: The decrease in IOP was 8.9 +/- 5.4 mmHg at 1 year, 10.0 +/- 4.2 mmHg at 5 years, and 8.9 +/- 5.2 mmHg at 10 years. The probability of success at 1 year was 77%, at 5 years 49%, and at 10 years 32%. Failure was most common in the first year after treatment (23%), and thereafter failure occurred at a rate of 5% to 9% per year. The mean decrease in IOP for all 93 eyes at time of maximum follow-up was 6.1 +/- 7.1 mmHg. CONCLUSION: Argon laser trabeculoplasty is an effective means for reducing IOP in many patients followed for an extended time. However, up to one half of eyes within 5 years of ALT and two thirds of eyes within 10 years may require additional laser or surgical intervention for glaucoma control.

Argon laser gonioplasty in the treatment of angle-closure glaucoma.

We used argon laser gonioplasty to treat angle-closure glaucoma unrelieved by patent iridectomy. Laser energy (mean; 30 spots, 723 mW, and 0.2 second) was applied to the peripheral iris stroma to open the anterior chamber angle. Twenty of 32 eyes were successfully treated. After a median follow-up period of 18 months, 17 of these 20 successfully treated eyes (85%) had an intraocular pressure less than or equal to 19 mm Hg, and 19 of these 20 successfully treated eyes (95%) had an intraocular pressure less than or equal to 21 mm Hg. The 20 successfully treated eyes had a median duration of angle closure of 12 days. Twelve unsuccessfully treated eyes had a median duration of angle closure of 90 days. All successfully treated eyes had more than 50% of the treated angle opened by argon laser gonioplasty and all but three successfully treated eyes had more than three clock hours opened by argon laser gonioplasty. Argon laser gonioplasty may be successful in treating angle-closure glaucoma unrelieved by iridectomy, especially in cases that are recognized and treated soon after onset.

Management of encapsulated filtration blebs.

Increased intraocular pressure (IOP) in encapsulated filtration blebs was evaluated in 49 eyes of 49 patients followed for 6 to 48 months (mean +/- standard deviation, 19.7 +/- 12.6 months). Intraocular pressure increased from 10.2 +/- 7.5 mmHg at 1 week postfiltration surgery to a peak of 26.1 +/- 10.7 mmHg at 3 weeks postoperatively and then decreased to 16.2 +/- 5.0 mmHg at 16 weeks and remained stable through the follow-up period. Thirty-nine eyes had a final IOP of 19 mmHg or less; 35 eyes required medical therapy alone (antiglaucoma drops, oral carbonic anhydrase inhibitors, and/or digital massage) with a final IOP of 14.1 +/- 3.8 mmHg; and 14 eyes required surgical reintervention for medically uncontrolled IOP elevation, and five of these eyes required two or more surgical reoperative procedures. Vigorous medical therapy, including glaucoma medications, topical steroids, and digital massage, is particularly important for encapsulated blebs during the first 2 months after surgery. After this period, IOP decreases and often remains sufficiently reduced to avoid further surgical intervention.

The effect of anterior chamber depth on endothelial cell count after filtration surgery.

Eighteen patients undergoing glaucoma filtration surgery underwent specular microscopic examination 1 day prior to surgery and 4 to 6 months after surgery. Patients were evaluated postoperatively for the presence of iridocorneal or lenticular-corneal touch, anterior chamber depth, and inflammation. Ten eyes that maintained their anterior chamber following glaucoma filtration surgery did not have a significant decrease in corneal endothelial cell density. However, eight eyes that developed a shallow anterior chamber with iridocorneal touch had a mean (+/- SD) decrease of 265 +/- 185 cells (12.4%) peripherally and 250 +/- 243 cells (11.6%) centrally in corneal endothelial cell count. None of the patients with iridocorneal touch developed corneal edema after a mean follow-up of 44.4 +/- 18.0 months. Iridocorneal touch after glaucoma filtration surgery is associated with loss of endothelial cells yet appears to be well tolerated by the cornea.

The development of encapsulated filtering blebs.

The development of an encapsulated filtering bleb (Tenon's cyst) complicated 56 of 409 consecutive filtering operations (13.7%) performed during a 40-month period after January 1983. Fifteen eyes (27.8% of encapsulated blebs) required surgical revision. The recognition of bleb encapsulation occurred 20.4 +/- 12.7 days (mean +/- standard deviation) postoperatively. Prolonged duration of beta-adrenergic antagonist therapy was associated with an increased frequency of bleb encapsulation (180.6 +/- 128.5 weeks without encapsulation, 229.0 +/- 129.3 weeks with encapsulation, P less than 0.009). Bleb encapsulation occurred in 42 of 272 eyes with previous argon laser trabeculoplasty, but in only 4 of 85 eyes without any previous anterior segment laser (P less than 0.01). Encapsulated filtering blebs developed in 4 of 12 (33.3%) eyes with congenital glaucoma and 4 of 9 (44.4%) eyes with juvenile glaucoma (P less than 0.0002). The intraocular pressures (IOPs) in the eyes with encapsulated filtering blebs were significantly elevated at 1, 2, and 3 postoperative weeks, and at final follow-up compared with eyes without bleb encapsulation.

Long-term efficacy of argon laser trabeculoplasty.

Long-term efficacy of 360 degrees argon laser trabeculoplasty was studied in 118 eyes of 93 patients with uncontrolled chronic open-angle glaucoma. The mean intraocular pressure (IOP) decrease was 8.9 +/- 5.4 mmHg (mean +/- standard deviation [SD] in 71 eyes at 1 year, 9.3 +/- 4.3 mmHg (mean +/- SD) in 51 eyes at 3 years, and 10.3 +/- 3.9 mmHg (mean +/- SD) in 28 eyes at 5 years. The probability of success at 4 years (decrease in IOP greater than or equal to 3 mmHg, IOP less than or equal to 19 mmHg, stable visual field, stable optic nerve, and no further laser or surgical intervention) was 52%. Pretreatment IOP, diagnosis, previous operations, age, and sex were not significant determinants for success or failure. Eyes receiving argon laser trabeculoplasty before cataract surgery maintained control of IOP after surgery. Failure was most common in the first year after treatment (23%), and thereafter failure occurred at a rate of 7 to 10% per year.

Retreatment with argon laser trabeculoplasty.

Forty eyes in 37 patients that had previously successful 360 degrees argon laser trabeculoplasty were again found to have uncontrolled intraocular pressure (IOP) on maximally tolerated medical therapy and were retreated with argon laser trabeculoplasty to 180 degrees of the trabecular circumference. Successful retreatment was considered a decrease in IOP of 3 mmHg or more and sufficient to avoid further laser therapy or invasive glaucoma surgery. Laser trabeculoplasty retreatment was successful in 13 of the eyes treated (32%). Retreatment failed to control IOP in 27 of the retreated eyes (68%): either the IOP was not lowered by at least 3 mmHg (4 eyes) or the eyes required further laser therapy or surgery (23 eyes). The probability of successful IOP control 1 year after retreatment was 33% and only 14% after 1.75 years. No IOP elevations greater than 6 mmHg were recognized in the postlaser period. Although retreatment with argon laser trabeculoplasty can safely be used to control the IOP in some glaucomatous eyes, the likelihood of success is low.

Chronic and recurrent choroidal detachment after glaucoma filtering surgery.

Chronic and recurrent choroidal (ciliochoroidal) detachments developed following glaucoma filtration surgery in 14 eyes of 13 patients during a 9-year period. Three specific subgroups were identified: recurrent, inflammatory, and chronic (present for more than 6 months). The factors that may be related to the development of chronic and recurrent choroidal detachments included patient age (mean, 68.8 years), systemic hypertension or atherosclerotic heart disease, hyperopia, aqueous suppressant therapy, ocular inflammation, and full-thickness filtration surgery. A total of 46 choroidal detachments in 14 eyes were recorded and required drainage of suprachoroidal fluid on 34 occasions. All eyes developed visually significant cataracts, and complete resolution of the recurrent or chronic choroidal detachment occurred following cataract extraction in six eyes. Treatment of chronic and recurrent choroidal detachments should include intense therapy of ocular inflammation, discontinuation of medications that can incite ocular inflammation, discontinuation of topical and systemic aqueous suppressant therapy, and when a visually significant cataract is present, cataract extraction combined with a choroidal tap should be performed.

Pigmentary dispersion syndrome and pigmentary glaucoma. A prospective study of the natural history.

The natural evolution of pigmentary dispersion syndrome and pigmentary glaucoma was studied in 55 patients for six to 43 months (mean, 27 months). Active dispersion of pigment was observed in 45 eyes in 31 patients and was associated with worsening of glaucoma in 32 eyes. Dispersion of pigment was defined as active when there was increase in iris transillumination, increase in corneal pigmentation, or appearance of pigment granules on the surface of the lens in the pupil. There were no differences in the frequency of active dispersion of pigment and worsening of glaucoma comparing patients aged less than 44, 45 to 64, and 65 or more years. This study demonstrates that active dispersion of pigment is clinically detectable, is correlated with elevation of intraocular pressure, and continues to occur in older patients.

Prevention of intraocular pressure elevation following neodymium-YAG laser posterior capsulotomy.

Thirty-two eyes of 32 patients were treated with 0.5% timolol, 2% pilocarpine, or normal saline five and 30 minutes following neodymium-YAG laser posterior capsulotomy in a randomized, double-masked study. Mean maximum intraocular pressure (IOP) elevation was 8 +/- 2 mm Hg following treatment with normal saline, 5 +/- 3 mm Hg following treatment with 2% pilocarpine, and 1 +/- 2 mm Hg following treatment with 0.5% timolol. Fewer patients treated with 0.5% timolol developed an IOP elevation of 5 mm Hg or more than control patients. On aphakic patient treated with 0.5% timolol developed a maximum IOP greater than or equal to 40 mm Hg. We found that treatment with 0.5% timolol after neodymium-YAG laser posterior capsulotomy provides partial protection from IOP elevation.

Intraocular pressure elevation following Nd:YAG laser posterior capsulotomy.

Intraocular pressures (IOP) and tonographic outflow facilities were measured following neodymium (Nd): YAG laser posterior capsulotomy in 13 pseudophakic and 8 aphakic eyes. Mean intraocular pressure (IOP) peaked by three hours with a mean increase of 13 mmHg, remained elevated by 5 mmHg at 24 hours but returned to baseline by one week. Fourteen eyes (67%) had greater than or equal to 10 mmHg elevation and eight (38%) had greater than or equal to 40 mmHg maximum IOP. All the patients who eventually demonstrated a greater than or equal to 10 mmHg elevation within six hours of the capsulotomy initially had an IOP elevation greater than or equal to 5 mmHg at one hour. The mean outflow facility was reduced from 0.18 microl/min/mmHg before capsulotomy to 0.08 microl/min/mmHg (55%, P less than 0.0001) at four hours and was still decreased at 0.13 microl/min/mmHg (27%, P less than 0.05) at one week. Seventy-five percent of aphakic and 15% of pseudophakic patients had maximum IOP greater than or equal to 40 mmHg (P less than 0.01). Measurements should be performed one hour postlaser in all patients for IOP and three to four hours in aphakic patients, glaucomatous patients, patients receiving greater than or equal to 200 mjoules total laser energy, and patients with greater than or equal to 5 mmHg elevation at one hour in order to detect and treat significant IOP elevations.