The Advanced Glaucoma Intervention Study (AGIS): 11. Risk factors for failure of trabeculectomy and argon laser trabeculoplasty. Laser trabeculoplasty as supplementary treatment for primary open angle glaucoma. Primary argon laser trabeculoplasty vs pilocarpine. IV. Long-term effects on optic nerve head. Argon laser trabeculoplasty or trabeculectomy a prospective randomised block study. Argon laser trabeculoplasty in primary open-angle glaucoma--results in black Jamaican population. Argon laser trabeculoplasty with standard and long duration. Argon laser trabeculoplasty: comparison of bichromatic and monochromatic wavelengths. Bronchial reactivity in healthy individuals undergoing long-term topical treatment with beta-blockers. Peripheral anterior synechiae formation after trabeculoplasty. Diode laser compared with argon laser for trabeculoplasty. Early Manifest Glaucoma Trial: design and baseline data. Selective laser trabeculoplasty v argon laser trabeculoplasty: a prospective randomised clinical trial. Long-term functional outcome after early surgery compared with laser and medicine in open-angle glaucoma. The immediate pressure response to primary laser trabeculoplasty--a comparison of one- and two-stage treatment. The Glaucoma Laser Trial (GLT) and glaucoma laser trial follow-up study: 7. Results. Glaucoma Laser Trial Research Group. Influence of treatment protocol on the long-term efficacy of argon laser trabeculoplasty. Five-year results of a randomized, prospective, clinical trial of diode vs argon laser trabeculoplasty for open-angle glaucoma. Initial argon laser trabeculoplasty to the inferior vs superior half of trabecular meshwork.
To investigate the association of pre-intervention and post-intervention patient and eye characteristics with failure of argon laser trabeculoplasty (ALT) and trabeculectomy.
                Cohort study of participants in the Advanced Glaucoma Intervention Study.
                This multicenter study took place between 1988 and 2001. Between 1988 and 1992, 789 eyes of 591 patients aged 35 to 80 years with advanced glaucoma were randomized into one of two surgical treatment sequences: argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy or trabeculectomy-ALT-trabeculectomy. Upon study-defined failure (based on maximum medications, sustained intraocular pressure (IOP) elevation, visual field defect, and disk rim deterioration) of each intervention, patients were offered the subsequent intervention. Potential follow-up was 8 to 13 years. This report is based on data from 779 eyes that had at least 3 months of follow-up. The main outcome measures are failure of ALT and trabeculectomy, whether as first or second interventions. Effect size is measured by the hazard ratio (HR) and its corresponding 95% confidence interval (CI) obtained from Cox multiple regression analysis, where HR corresponds to the coefficient of change in risk associated with a unit increase in a factor. For binary factors, this corresponds to the change in risk in eyes with the factor relative to the risk in eyes without the factor.
                Pre-intervention factors associated with failure of ALT are younger age (HR = 0.98, CI = 0.96-0.99, P =.009) and higher IOP (1.11, 1.08-1.15, P <.001). Pre-intervention factors associated with failure of trabeculectomy are younger age (HR = 0.97, CI = 0.95-0.99, P =.005) and higher IOP (1.04, 1.01-1.06, P =.002), as well as diabetes (2.86, 1.88-4.36, P <.001) and any postoperative complication (1.99, 1.35-2.93, P <.001). Individual postoperative complications significantly associated with increased risk of failure of trabeculectomy are elevated IOP (3.4, 1.9-6.1, P <.001) and marked inflammation (2.4, 1.3-4.6, P =.006).
                In this study, ALT failure was associated with younger age and higher pre-intervention IOP. Trabeculectomy failure was associated with younger age, higher pre-intervention IOP, diabetes, and one or more postoperative complications, particularly elevated IOP and marked inflammation. A prospective trial was conducted of laser trabeculoplasty randomly assigned to one eye of a group of elderly patients with bilateral primary phakic open angle glaucoma who were already taking the maximum medical treatment that they could tolerate. With a minimum follow-up of 2 1/2 years (mean 35 months) a significant fall in mean intraocular pressure of over 7 mmHg (30%) at the time of the patient's last visit was noted in the treated eye. In a prospective, randomized study on primary argon laser trabeculoplasty vs piloparpine in 82 newly detected open-angle glaucomas the progress of optic nerve head damage is presented. In 70 patients reliable stereo photographs could be analysed. In the laser treated group a progression of glaucoma damage after 24 months was seen in 6/37 eyes (16%) and in the pilocarpine-treated group 16/33 (49%) (p = 0.0048). There was a statistically significant favourable outcome if intraocular pressure was regulated in terms of peak and range of pressure, but not average pressure. This was even more pronounced in capsular glaucoma, but not significant for simple glaucoma. Pilocarpine increased the risk for further damage to the optic nerve head 6.4 times compared to laser trabeculoplasty. Thus, laser is recommended as the primary therapy in high tension glaucoma, especially in capsular glaucoma. A prospective randomised block study of treatment by either argon laser trabeculoplasty or trabeculectomy was undertaken in patients with chronic open angle glaucoma not controlled by medication. The study was undertaken in two centres in the United Kingdom where the regimes of medical treatment prior to interference were different. Regression analysis showed that in both populations laser trabeculoplasty was effective in reducing the intraocular pressure but it was less effective than trabeculectomy in permanently reducing the intraocular pressure to within normal limits. Laser trabeculoplasty was most effective in those patients whose intraocular pressure was initially high but many of these required post-operative medication or surgery. Laser trabeculoplasty is a useful adjunct to the therapy of open angle glaucoma but it is not a substitute for trabeculectomy as a method of permanently reducing the intraocular pressure to normal. Because of the effectiveness of both these methods of treatment we feel it no longer justified to use anything other than simple local medication to control the intraocular pressure before proceeding to active therapy. A controlled, randomised, prospective trial of Argon laser trabeculoplasty (ALT) was carried out on 48 eyes of 30 black Jamaican patients with primary open-angle glaucoma. All eyes had uncontrolled intra-ocular pressures (greater than or equal to 22 mm Hg) despite medical therapy. Treatment was successful in controlling intraocular pressure in 68% of eyes after 12 months follow-up (p = 0.004). The average drop in intraocular pressure attributable to ALT was 6.6 mmHg. Argon laser trabeculoplasty is an effective adjunct in managing to control intraocular pressure in black Jamaican glaucoma patients. A prospective study of 0.1 sec and 0.2 sec duration argon laser trabeculoplasty was undertaken in 33 patients with chronic simple glaucoma. Patients were randomly allocated to receive 0.1 sec trabeculoplasty to the eye and 0.2 sec trabeculoplasty to the other. No difference was found in the fall in intra-ocular pressure or in glaucoma control between the two durations over the six months of the study. However, 0.2 sec argon laser trabeculoplasty was reported to be more uncomfortable of 60% of patients. A randomized prospective study was undertaken to examine the effects of bichromatic argon laser therapy and monochromatic argon laser therapy when used for trabeculoplasty in chronic open angle glaucoma. Fifty patients underwent laser trabeculoplasty with the continuous wave argon laser emitting wavelengths of multiple lines (454.5 nm to 528.7 nm) in the bichromatic spectrum (blue and green). Fifty additional patients underwent laser trabeculoplasty using a continuous-wave argon laser emitting a monochromatic (green) wavelength at 514.5 nm. Patients treated with the bichromatic laser had an average decrease in their intraocular pressure of -7.1 +/- 5.2 mmHg and patients treated with the monochromatic laser had an average decrease of -8.0 +/- 6.2 mmHg. The length of the follow-up was 2 to 13 months with an average of 10 months. For each group, this decrease in intraocular pressure from the pretreatment values was statistically significant (P less than 0.001). However, there was no statistically significant difference in the decrease in the intraocular pressure between the two groups (P = 0.34). No differences were noted in the postoperative course or in the complication rate between the two groups. To assess the impact of long-term treatment with topical timolol on bronchial reactivity in healthy individuals.
                Twenty-one otherwise healthy individuals with high-pressure primary open-angle glaucoma were enrolled in a randomized controlled clinical trial. Eleven patients underwent 3 years of topical 0.5% timolol treatment followed by a 1-year washout period; 10 patients underwent primary argon laser trabeculoplasty. Functional variables and bronchial reactivity (forced expiratory volume in 1 second and metacholine challenge test results) were assessed in both groups at enrollment and after 3 and 4 years of follow-up.
                After 3 years, a measurable response to metacholine challenge was recorded in 6 of 11 otherwise symptom-free individuals treated with 0.5% timolol twice daily. A detectable response to metacholine challenge was still present in half of these individuals (3 of 6) when further washed out for 1 year from the topical beta-blocker. No significant variation in bronchial reactivity was measured in the laser-treated group during 4 years of follow-up.
                Healthy individuals who undergo long-term topical application of a nonselective beta-blocker (0.5% timolol) can develop a subclinical increase in bronchial reactivity. This phenomenon may not be completely reversible on withdrawal of the beta-blocker. Argon laser trabeculoplasty (ALT) was performed on 60 eyes with primary open angle glaucoma and 59 eyes with capsular (pseudoexfoliation) glaucoma. Laser applications of four different power levels (500, 600, 700, and 800 mW) were directed either at the anterior trabecular meshwork or at the posterior trabecular meshwork. Gonioscopic examination to reveal peripheral anterior synechiae (PAS) formation was performed before and six months after ALT. Peripheral anterior synechiae were found in 26 (22%) of the eyes. With 500-mW laser power and anterior trabecular meshwork burns, no PAS developed. With 800-mW posterior trabecular meshwork burns, PAS developed in 12 (40%) of the eyes. No correlation between PAS formation and sex, age, glaucoma type, preoperative antiglaucoma medication, pigmentation of the chamber angle, and visible burn effect was found. Intraocular pressure decrease after ALT was significantly smaller in eyes with PAS. A randomized prospective study on two groups of ten patients compared the efficacy of diode laser and argon laser trabeculoplasty. In the diode laser group the intraocular pressure was 23.0 +/- 3.97 mm Hg before the treatment, 20.2 +/- 4.49 mm Hg at two hours, 16.3 +/- 3.13 at six months, and 16.9 +/- 2.80 mm Hg at one year. The differences from baseline were statistically significant at six months (P = .0001) and at one year (P = .0001) but not at two hours. In the argon laser group the intraocular pressure was 23.4 +/- 3.6 mm Hg before the treatment, 22.7 +/- 4.35 mm Hg at two hours, and 17.6 +/- 4.53 mm Hg at six months. One patient had uncontrolled mean high intraocular pressure and underwent surgery. In the nine patients who completed the study the intraocular pressure at one year was 16.7 +/- 3.00 mm Hg. The differences from baseline were significant at six months (N = 10; P = .0001) and 12 months (N = 9; P = .0001) but not at two hours. Differences between the two groups were not significant at two hours, six months, and one year. Laser trabeculoplasty may be effectively with a diode laser. The Early Manifest Glaucoma Trial (EMGT) will evaluate the effectiveness of reducing intraocular pressure (IOP) in early, previously untreated open-angle glaucoma. Its secondary aims are to explore factors related to glaucoma progression and to study the natural history of the disease. This article describes the EMGT design and presents baseline data.
                Randomized, clinical trial.
                Newly diagnosed patients 50 to 80 years of age with early glaucomatous visual field defects were mainly identified from a population-based screening of more than 44,000 residents of Malmö and Helsingborg, Sweden. Exclusion criteria were advanced visual field loss; mean IOP greater than 30 mmHg or any IOP greater than 35 mmHg; visual acuity less than 0.5; and inability to complete follow-up protocols.
                After informed consent, patients were randomized to treatment or no initial treatment with close follow-up. Treated patients had laser trabeculoplasty and started receiving topical betaxolol twice daily in eligible eyes. Follow-up visits include computerized perimetry and tonometry every 3 months and fundus photography every 6 months. Decisions to change or begin treatment are made jointly with the patient when EMGT progression occurs and also later if clinically needed.
                The EMGT progression is defined by sustained increases of visual field loss in three consecutive C30-2 Humphrey tests, as determined from computer-based analyses, or by optic disc changes, as determined from flicker chronoscopy and side-by-side comparisons of fundus photographs performed by masked, independent graders.
                A total of 255 patients were randomized between 1993 and 1997 and will be followed for at least 4 years. All had generally good health status; mean age was 68.1 years, and 66% were women. At baseline, mean IOP was 20.6 mmHg and 80% of eyes had IOP less than 25 mmHg.
                The Early Manifest Glaucoma Trial is the first large randomized, clinical trial to evaluate the role of immediate pressure reduction, as compared to no initial reduction, in patients with early glaucoma and normal or moderately elevated IOP. Its results will have implications for: (1) the clinical management of glaucoma; (2) understanding the role of IOP and the natural history of glaucoma; and (3) evaluating the rationale for glaucoma screening. To compare the effectiveness of selective laser trabeculoplasty (SLT, a 532 nm Nd:YAG laser) with argon laser trabeculoplasty (ALT) in lowering the intraocular pressure (IOP) in patients with medically uncontrolled open angle glaucoma.
                A prospective randomised clinical trial was designed. Patients were randomised to treatment with either SLT or ALT and were evaluated at 1 hour, 1 week, 1, 3, and 6 months post-laser.
                There were 18 eyes in each group. Baseline characteristics were similar in both groups. In the SLT group the mean IOP at baseline, 1, 3, and 6 months was 22.8 (SD 3.0), 20.1 (4.6), 19.3 (6.0), and 17.8 (4.8) mm Hg, respectively. In the ALT group, the mean IOP at baseline, 1, 3, and 6 months was 22.5 (3.6), 19.5 (4.7), 19.6 (5.6), and 17.7 (3.3) mm Hg, respectively. There was a greater anterior chamber reaction, 1 hour after SLT v ALT (p< 0.01). Patients with previous failed ALT had a better reduction in IOP with SLT than with repeat ALT (6.8 (2. 4) v 3.6 (1.8) mm Hg; p = 0.01).
                SLT appears to be equivalent to ALT in lowering IOP during the first 6 months after treatment. There is a slightly greater anterior chamber reaction 1 hour after SLT. Patients with previous failed ALT had a significantly greater drop in IOP when treated with SLT v ALT. These results need to be confirmed with a larger sample size. This randomly allocated prospective clinical study was designed to assess the relative efficacy of laser trabeculoplasty, medical therapy, and trabeculectomy used as the primary treatment in open-angle glaucoma, with particular regard to the level of intraocular pressure control and the amount of visual field decay. No patient had received any antiglaucoma treatment before entry into the trial.
                One hundred sixty-eight patients were entered into the trial and randomly allocated into one of the three treatment groups--laser, medicine, or surgery. Follow-up was for a minimum of 5 years. The patients were monitored in the standard way, including intraocular pressure estimations and visual field tests (initially using the Friedmann analyzer and later including Humphrey automated perimetry).
                Despite similar initial composition of the three treatment groups, primary surgery resulted in the lowest mean intraocular pressures. The perimeter Friedmann visual fields were shown to have deteriorated in patients in the medicine-treated group and to a lesser extent in patients in the laser-treated group, but not in patients in the surgery-treated group. Multivariate linear regression analysis showed that the difference in field changes between laser and surgical treatments could be explained entirely by the difference between the intraocular pressure values at 6 months between the two groups. The same was not true for the medicine-treated group.
                Primary trabeculectomy appears to have the desired effect in preserving visual function in patients with high-tension glaucoma. This may be related to laser treatment might be expected to have the same effect. The immediate pressure response to primary LTP was studied prospectively in 40 eyes randomised to one- and two-stage treatment in 360 degrees of the trabecular meshwork. There were 26 eyes with glaucoma capsulare and 14 with glaucoma simplex. Mean prelaser IOP was 32.8 mmHg in the former, and 35.5 mmHg in the latter group. The frequency and magnitude of postlaser pressure increase were the same in both groups when taking into consideration the pressure spikes in both 180 degrees sessions. The pressure increase was higher than in earlier reports on LTP in presurgical glaucoma patients on maximum medication. Almost all IOP elevations appeared during the first 2 h following laser treatment. The results were the same in both groups 6 months after LTP. To determine differences between the two treatment groups of the Glaucoma Laser Trial with respect to intraocular pressure, visual fields, optic disk cupping, and therapy for primary open-angle glaucoma.
                The Glaucoma Laser Trial was a multicenter, randomized clinical trial designed to assess the efficacy and safety of starting treatment for primary open-angle glaucoma with argon laser trabeculoplasty vs starting with topical medication. The Glaucoma Laser Trial Follow-up Study was a follow-up study of 203 of the 271 patients who enrolled in the Glaucoma Laser Trial. By the close of the Glaucoma Laser Trial Follow-up Study, median duration of follow-up since diagnosis of primary open-angle glaucoma was seven years (maximum, nine years).
                Over the course of the Glaucoma Laser Trial and Glaucoma Laser Trial Follow-up Study, the eyes treated initially with argon laser trabeculoplasty had lower intraocular pressure and better visual field and optic disk status than their fellow eyes treated initially with topical medication. As compared to eyes initially treated with medication, eyes initially treated with laser trabeculoplasty had 1.2 mm Hg greater reduction in intraocular pressure (P < .001) and 0.6 dB greater improvement in the visual field (P < .001) from entry into the Glaucoma Laser Trial. The overall difference between eyes with regard to change in ratio of optic cup area to optic disk area from entry into the Glaucoma Laser Trial was -0.01 (P = .005), which indicated slightly more deterioration for eyes initially treated with medication.
                Initial treatment with argon laser trabeculoplasty was at least as efficacious as initial treatment with topical medication. Forty-five phakic eyes of 36 patients with open-angle glaucoma and uncontrolled intraocular pressure despite maximally tolerated medication underwent initial argon laser trabeculoplasty (ALT) in 1981 and 1982 as part of a prospective, randomized study to evaluate the effectiveness of different treatment standards. Each eye had been randomly assigned to receive either 100 laser applications over 360 degrees of trabecular meshwork, 50 applications over 180 degrees , or 50 applications over 360 degrees in a single session. Further treatment in each group was based on clinical standards prevailing at the time. The long-term results were analyzed using Kaplan-Meier survival analyses. By 4 years after initial ALT, six of the 15 remaining eyes in group 1 (40%), one of 14 eyes in group 2 (7%), and two of 13 eyes in group 3 (15%) had undergone filtration surgery, and one eye in group 1 (7%), three eyes in group 2 (21%), and three eyes in group 3 (23%) had received further ALT. By 7 years after initial ALT, seven of the nine remaining eyes in group 1 (78%), one of 12 eyes in group 2 (8%), and four of 12 eyes in group 3 (33%) received filtration surgery, and two eyes in group 1 (22%), three eyes in group 2 (25%), and four eyes in group 3 (33%) had received further ALT. Kaplan-Meier survival curves predict the following probabilities of avoiding either repeat ALT or filtration surgery at 4 years after an initial ALT: group 1, 54 +/- 12%; group 2, 76 +/- 12%; and group 3, 62 +/- 11%. Our results suggest that performing 50 rather than 100 burns at initial ALT may significantly delay the need for additional surgical or repeat laser intervention. To evaluate the safety and efficacy of laser trabeculoplasty (LTP) with a semiconductor diode laser (810 nm, [DLT]) vs an argon blue-green laser (488 to 514 nm, [ALT]).
                In a prospective, randomized clinical trial, 50 eyes of 46 patients with uncontrolled open-angle glaucoma on maximally tolerated medical therapy were treated and followed at regular intervals for 5 years. Fifty laser spots were applied over 180 degrees using either maximal laser power or sufficient power to produce blanching or a small bubble (570 to 850 mW, DLT; 400 to 1,100 mW, ALT). We performed DLT using a 100-microm spot size, a 0.5-second exposure, and a Ritch lens; we conducted ALT with a 50-microm spot, a 0.1-second exposure, and a Goldmann lens. Patients in the study were followed until trabeculectomy was required.
                The mean follow-up times +/- SD for all eyes were 38.6 +/- 5.4 months, DLT (n = 22; range, 1 to 68 months) and 35.5 +/- 4.8 months, ALT (n = 28; range, 1 to 66 months). Those in the diode laser group (n = 16) who had more than 1 year of follow-up were tracked for 49.4 months, and those in the argon laser group (n = 21) were tracked for 45.8 months. There were no significant differences in the mean pretreatment intraocular pressures (IOPs): 21.2 mm Hg, DLT (n = 22) and 21.5, ALT 21.5 mm Hg (n = 28); P = .81] or in mean final IOPs (15.7 mm Hg, DLT and 17.1 mm Hg, ALT; P = .19). Time to surgical failure showed no significant differences, with 50% of the DLT eyes and 58% of the ALT eyes surviving at 5 years (P = .59).
                In eyes with open-angle glaucoma and unsatisfactory IOP control on maximally tolerated medical therapy, DLT and ALT are equally effective in lowering IOP over a 5-year period. nan
Evidence suggests that, in people with newly diagnosed OAG, the risk of uncontrolled IOP is higher in people treated with medication used before the 1990s when compared to laser trabeculoplasty at two years follow up. Trabeculoplasty is less effective than trabeculectomy in controlling IOP at six months and two years follow up. Different laser technology and protocol modalities were compared to the traditional laser trabeculoplasty and more evidence is necessary to determine if they are equivalent or not. There is no evidence to determine the effectiveness of laser trabeculoplasty compared to contemporary medication (prostaglandin analogues, topical anhydrase inhibitors and alpha2-agonists) and also with contemporary surgical techniques. Also there should be further investigation in to the effectiveness of laser trabeculoplasty in specific racial groups, specific diagnostic groups, such as pseudoexfoliation and pigmentary glaucoma and different stages of OAG. More research is also required determining cost-effectiveness of laser trabeculoplasty in the management of glaucoma.