5-fluorouracil in combined trabeculectomy and clear-cornea phacoemulsification with posterior chamber intraocular lens implantation. A one-year randomized, controlled clinical trial. The immediate pressure response to primary laser trabeculoplasty--a comparison of one- and two-stage treatment. Long-term functional outcome after early surgery compared with laser and medicine in open-angle glaucoma. The Advanced Glaucoma Intervention Study (AGIS): 11. Risk factors for failure of trabeculectomy and argon laser trabeculoplasty. Selective laser trabeculoplasty v argon laser trabeculoplasty: a prospective randomised clinical trial. The Glaucoma Laser Trial (GLT) and glaucoma laser trial follow-up study: 7. Results. Glaucoma Laser Trial Research Group. Randomized controlled clinical trial of beta irradiation as an adjunct to trabeculectomy in open-angle glaucoma. Five-year results of a randomized, prospective, clinical trial of diode vs argon laser trabeculoplasty for open-angle glaucoma. Long-term follow-up of primary glaucoma surgery with Ahmed glaucoma valve implant versus trabeculectomy. Early trabeculectomy versus conventional management in primary open angle glaucoma. Early Manifest Glaucoma Trial: design and baseline data. Laser trabeculoplasty as supplementary treatment for primary open angle glaucoma. Interim clinical outcomes in the Collaborative Initial Glaucoma Treatment Study comparing initial treatment randomized to medications or surgery. 5-Fluorouracil in initial trabeculectomy. A prospective, randomized, multicenter study. Argon laser trabeculoplasty or trabeculectomy a prospective randomised block study. Argon laser trabeculoplasty with standard and long duration. Diode laser compared with argon laser for trabeculoplasty. A prospective, comparative study between endoscopic cyclophotocoagulation and the Ahmed drainage implant in refractory glaucoma.
To test the effect of postoperative subconjunctival 5-fluorouracil (5-FU) on the pressure outcome in combined procedure (limbus-based trabeculectomy + clear-cornea phacoemulsification).
                Prospective randomized, controlled clinical trial; n = 24 eyes (24 patients) with concurrent open-angle glaucoma and cataract; 12 eyes per treatment group; sample size adjusted for a minimal expected difference in the event rate between the 2 treatment groups = 50%, control rate = 20%; type I error = 0.05; power = 95%. Uncomplicated limbus-based trabeculectomy + uncomplicated clear-cornea phacoemulsification + posterior chamber intraocular lens. The 5-FU group = five subconjunctival injections of 5 mg 5-FU, starting from day 8 after surgery, one injection per week. Control group = no injections. The groups were matched for age, preoperative intraocular pressure (IOP), duration of preoperative antiglaucoma treatment, preoperative pilocarpine and adrenergics, preoperative laser trabeculoplasty, and beta-blockers in the fellow eye. The IOP less than or equal to 15 mmHg without treatment 1 year after surgery (IOP = average of the two highest values measured in the diurnal curve, 8 AM to 6 PM, one reading every 2 hours).
                Each patient completed a 1-year follow-up. Ten of 12 eyes of the 5-FU group showed an IOP less than or equal to 15 mmHg at the end of follow-up versus 1 of 12 eyes in the control group (Fisher's exact test, P = 0.00064). The IOP range was 10 to 17 mmHg in the 5-FU group and 14 to 22 mmHg in the control group.
                Postoperative 5-FU may improve the 1-year success rate of trabeculectomy combined with clear-cornea phacoemulsification. 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. 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. 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. 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. 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. To assess the effect of a single intraoperative application of 750 cGy of beta irradiation on the outcome of trabeculectomy for uncontrolled open-angle glaucoma.
                A prospective, randomized, double-blind, placebo-controlled clinical trial.
                Sixty-one eyes of 61 Caucasian patients at low risk of filtering surgery failure, with poorly controlled primary or secondary open-angle glaucoma undergoing routine trabeculectomy.
                Patients were randomly assigned to control or beta irradiation groups. All patients underwent standard trabeculectomy with fornix-based conjunctival incision. Eyes assigned to beta irradiation received 750 cGy of beta irradiation directly over the sclerostomy site on completion of conjunctival suturing. An identical but inactive applicator was applied to control eyes, delivering no radiation. Both operator and patient remained masked to the assignment for the 12-month follow-up period.
                The main outcome measure was intraocular pressure (IOP) control. Complete success of IOP control was defined as an IOP less than 21 mmHg at 12 months without need for additional medication. Qualified success was defined as an IOP less than 21 mmHg at 12 months where additional medication was required.
                Complete success of IOP control was achieved in 19 (86%) control eyes and 35 (90%) irradiated eyes (P = 1.0). Qualified success of IOP control was achieved in 21 (95%) control eyes and 39 (100%) irradiated eyes at 12 months follow-up (P = 1.0)
                We experienced a very high success rate of filtration surgery in this select population without adjunctive irradiation. Our sample size was too small to show any improvement in success with use of beta irradiation in this group. Other studies would have to be done to determine whether it may have measurable benefit in cases with a high risk of filtration failure. 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. To compare the long-term results of trabeculectomy and Ahmed glaucoma valve implant in the initial surgical management of primary open- and closed-angle glaucoma.
                Randomized controlled clinical trial.
                One eye each of consecutive patients with primary glaucoma and without prior intraocular surgery was randomized to receive either trabeculectomy or the Ahmed implant. Large university-affiliated eye hospital in Columbo, Sri Lanka.
                Of 123 patients, 64 were randomized to trabeculectomy and 59 to the Ahmed implant. With a mean follow-up of 31 months, the trabeculectomy group had statistically lower intraocular pressures (IOP) during the first postoperative year. After the first year, the IOPs were comparable. No statistically significant differences between groups were noted for postoperative visual acuity, visual field, anterior chamber depth, and short-term or long-term complications. Adjunctive medication requirement was comparable for both groups. The cumulative probabilities of success (IOP <21 mm Hg and at least 15% reduction in IOP from preoperative levels) at the final follow-up period (months, 41-52) were 68.1% for trabeculectomy and 69.8% for Ahmed implant (P =.86).
                Lower IOPs were noted for the trabeculectomy group during the first year. With longer follow-up, the IOPs and the cumulative probabilities of success were comparable between the two groups. The results of a randomised, prospective, multicentre trial of the management of primary open angle glaucoma are presented at up to five years' follow up. Previously undiagnosed cases were selected with intraocular pressure of 26 mmHg or more on two occasions together with field loss characteristic of glaucoma. Analysis was performed on one eye selected at random from each of 99 patients. Conventional medical treatment followed in unsuccessful cases by trabeculectomy (group A) was compared with trabeculectomy at diagnosis followed when necessary by supplementary medical therapy (group B). The life expectancy of these glaucoma patients was found to be similar to that for the local population matched for age and sex. In group A after four years trabeculectomy had been performed in 53% of eyes because medical management had failed to control the disease. The rate of operation was lower in those patients with intraocular pressure less than 31 mmHg and mild relative field loss (17% at three years) than in those with intraocular pressure greater than 30 mmHg and dense scotomas (75% at three years). Early surgery provided much more stable control with fewer changes in treatment than in group A. The group mean intraocular pressure after trabeculectomy was 15.0 mmHg irrespective of the time of operation, and this was significantly lower than the intraocular pressure in those cases thought to be controlled on medical therapy alone at the end of the first year (20.8 mmHg). Early operation provided significantly better protection of visual field, and the extra loss of visual field with delayed operation occurred in the preoperative period. Changes in visual fields were not related to the use of miotics. There was no significant difference in the final visual acuity in the two groups, but six cases in group A lost central fixation because of progressive loss of visual field, and there were no such cases in group B. Cataract occurred in approximately 10% of cases in both groups, but in group A this happened with only half the number of operations and at a shorter postoperative follow-up than in group B. It appears that in cases of primary open angle glaucoma of this severity the risk of delaying operation are significantly greater than those of performing trabeculectomy as the primary treatment. 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. 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. To report interim outcome data, using all available follow-up through 5 years after treatment initiation, in the Collaborative Initial Glaucoma Treatment Study (CIGTS).
                Randomized clinical trial.
                Six hundred seven newly diagnosed glaucoma patients.
                In a randomized clinical trial, 607 patients with newly diagnosed open-angle glaucoma were initially treated with either medication or trabeculectomy (with or without 5-fluorouracil). After treatment onset and early follow-up, patients were evaluated clinically at 6-month intervals. In addition, quality of life telephone interviews were conducted at similar frequency to the clinical visits. Patients in both arms of CIGTS were treated aggressively in an effort to reduce intraocular pressure (IOP) to a level at or below a predetermined target pressure specific for each individual eye. Visual field (VF) scores were analyzed by time-specific comparisons and by repeated measures models.
                VF loss was the primary outcome variable in CIGTS. Secondary outcomes of visual acuity (VA), IOP, and cataract were also studied.
                On the basis of completed follow-up through 4 years and partially completed through 5 years, VF loss did not differ significantly by initial treatment. Over the entire period of follow-up, surgical patients had a greater risk of substantial VA loss compared with medical patients. However, by 4 years after treatment, the average VA in the two groups was about equal. Over the course of follow-up, IOP in the medicine group has averaged 17 to 18 mmHg, whereas that in the surgery group averaged 14 to 15 mmHg. The rate of cataract requiring removal was greater in the surgically treated group.
                Both initial medical or initial surgical therapy result in about the same VF outcome after up to 5 years of follow-up. VA loss was greater in the surgery group, but the differences between groups seem to be converging as follow-up continues. When aggressive treatment aimed at substantial reduction in IOP from baseline is used, loss of VF can be seen to be minimal in general. Because 4 to 5 years of follow-up in a chronic disease is not adequate to draw treatment conclusions, these interim CIGTS outcomes do not support altering current treatment approaches to open-angle glaucoma. Postoperative subconjunctival 5-fluorouracil (5-FU) injections increase the success of filtration surgery in eyes with prior filtration failure or cataract removal and in eyes with secondary glaucoma. The authors evaluate the safety and benefit of adjunctive 5-FU in eyes undergoing initial trabeculectomy.
                Patients with phakic, uncontrolled, open-angle glaucoma who were undergoing initial trabeculectomy were prospectively assigned to the 5-FU group on the first postoperative day. Patients in this group received five 5-mg injections during 2 weeks after surgery. Patients in the control group received no injections.
                Preoperative intraocular pressure (IOP) and number of antiglaucoma medications were similar in the 5-FU (n = 32) and control (n = 30) groups. Transient superficial punctate keratopathy was the only postoperative complication that occurred more frequently (P < 0.05) in the 5-FU (14 eyes) than in the control eyes (3 eyes). Patients were followed for a minimum of 1 year or until a study endpoint was reached: IOP of 21 mmHg or greater with maximum medical therapy (2 5-FU eyes and 8 control eyes; P < 0.03) or cataract removal after filtration (5 treated and 3 control eyes). At last follow-up (mean, > 20 months), IOP and the number of antiglaucoma medications were significantly lower (P < 0.02) in the 5-FU eyes (IOP, 12.0 +/- 1.3 mmHg; medications, 0.2 +/- 0.1) than in the control eyes (IOP, 16.8 +/- 1.3 mmHg; medications, 0.8 +/- 0.2). Intraocular pressure was 20 mmHg or lower in 94% of 5-FU eyes and in 73% of control eyes (P < 0.03) and 16 mmHg or lower in 84% of 5-FU eyes and in 57% of control eyes (P < 0.02).
                Adjunctive 5-fluorouracil increases the rate of success, decreases the level of postoperative IOP, and reduces the need for postoperative antiglaucoma medication in eyes with open-angle glaucoma undergoing initial trabeculectomy. 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 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 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. To compare endoscopic cyclophotocoagulation (ECP) and the Ahmed drainage implant in the treatment of refractory glaucoma.
                Sixty-eight eyes of 68 patients with refractory glaucoma were prospectively assigned to either ECP or Ahmed tube shunt implantation. All procedures were performed by a single surgeon. Eyes that were included were pseudophakic with a history of at least one trabeculectomy with antimetabolite, an intraocular pressure (IOP) equal to or above 35 mm Hg on maximum tolerated medical therapy, and a visual acuity better than light perception. Exclusion criteria included eyes that had had previous glaucoma drainage device implantation or a cyclodestructive procedure. Success was defined as an IOP more than 6 mm Hg and less than 21 mm Hg, with or without topical anti-hypertensive therapy.
                The mean follow-up was 19.82 +/- 8.35 months and 21.29 +/- 6.42 months, for the Ahmed and ECP groups, respectively (P = 0.4). The preoperative IOP, 41.32 +/- 3.03 mm Hg (Ahmed) and 41.61 +/- 3.42 mm Hg (ECP) (P = 0.5), and the mean postoperative IOP, at 24 months follow-up, 14.73 +/- 6.44 mm Hg (Ahmed) and 14.07 +/- 7.21 mm Hg (ECP) (P = 0.7), were significantly different from baseline in both groups (P < 0.001). Kaplan-Meier survival curve analysis showed a probability of success at 24 months of 70.59% and 73.53% for the Ahmed and ECP groups, respectively (P = 0.7). Complications included choroidal detachment (Ahmed 17.64%, ECP 2.94%), shallow anterior chamber (Ahmed 17.64%, ECP 0.0%), and hyphema (Ahmed 14.7%, ECP 17.64%).
                There was no difference in the success rate between the Ahmed Glaucoma Valve and ECP in refractory glaucoma. The eyes that underwent Ahmed tube shunt implantation had more complications than those treated with ECP.
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.