Selective vs argon laser trabeculoplasty: hypotensive efficacy, anterior chamber inflammation, and postoperative pain

The influence of topical prostaglandin analogues in inflammation after selective laser trabeculoplasty treatment

PURPOSE

Reducing intraocular pressure (IOP) seems to be the only treatment that slows progression in glaucoma. The IOP can be decreased by pharmaceutical treatment, laser [selective laser trabeculoplasty (SLT)] treatment, or surgery. Prostaglandin analogues have been postulated to share action mechanisms with SLT and to possibly diminish the effects of SLT treatment. The aim of the current study was to investigate the effects of prostaglandin analogues in inflammation and IOP reduction after SLT treatment.

METHODS

Prospective nonrandomized study. One hundred and eighteen patients were included in the study.

INCLUSION CRITERIA

Glaucoma (open-angle or pseudoexfoliation glaucoma) patients who will be treated with SLT. Inflammation was measured with a laser flare meter (Kowa FM-500). Measurements were made before SLT and then 2 h, 1 week, and 1 month after SLT treatment. IOP was also checked at the same time intervals. The SLT treatment was performed over 90°. All patients were divided into two groups: those receiving prostaglandins analogues and those treated with nonprostaglandin analogues.

RESULTS

Inflammation before and after SLT showed no significant difference between the groups at all the time intervals studied (t-test, before: P=0.16; 2 h: P=0.14; 1 week: P=0.12; and 1 month: P=0.36). IOP reduction showed no significant difference between the groups (t-test, P=0.31).

CONCLUSIONS

SLT treatment effects do not seem to be influenced by the use of prostaglandin analogues.

Comparison of selective laser trabeculoplasty (SLT) in primary open angle glaucoma and pseudoexfoliation glaucoma

Background and objective

The aim of the present study was to compare intraocular pressure (IOP) reduction and inflammation after selective laser trabeculoplasty (SLT) treatment in patients suffering from primary open angle (POAG) vs pseudoexfoliative (PXFG) glaucoma.

Study design/patients and methods

Sixty patients (60 eyes) participated in the study. Glaucoma patients (POAG or PXFG) scheduled for treatment with SLT were included. Inflammation was measured with a laser flare meter (Kowa FM-500). Measurements were made before SLT and 2 hours, 1 week, and 1 month after SLT treatment. IOP was also checked at the same time intervals.

Results

Inflammation after SLT showed no significant difference between the groups (t-test, before: P = 0.16; 2 hours: P = 0.14; 1 week: P = 0.12; and 1 month: P = 0.36). IOP reduction was the same in both groups (t-test, P = 0.27).

Conclusion

SLT safely reduces IOP in both POAG and PXFG. Pseudoexfoliation does not seem to be a risk factor for post-laser complications.

Micropulse diode laser trabeculoplasty (MDLT): A phase II clinical study with 12 months follow-up

Objective

This pilot study evaluates the pressure lowering potential of subthreshold micropulse diode laser trabeculoplasty (MDLT) for a clinically meaningful duration in patients with medically uncontrolled open angle glaucoma (OAG).

Design

prospective interventional case series.

Participants

Thirty-two eyes of 20 consecutive patients with uncontrolled OAG (12 bilateral and 8 unilateral).

Methods

Confluent subthreshold laser applications over the inferior 180° of the anterior TM using an 810 nm diode laser in a micropulse operating mode. The intraocular pressure (IOP) was measured at baseline and at 1 hour, 1 day, 1 week, 3, 6, 9, and 12 months post-treatment. Flare was measured with a Kowa FM 500 flare-meter at baseline and at 3 hours, 1 day, 1 week, and 12 months post-treatment. After treatment, the patients were maintained on their pre-treatment drug regimen.

Main outcome measures

Criteria for treatment response were IOP reduction ≥3 mm Hg and IOP ≤21 mm Hg within the first week after MDLT. Eyes not complying to the above criteria during the follow-up were considered treatment failure. Mean IOP change and percentage of IOP reduction during the follow-up were calculated.

Results

One eye was analyzed for bilateral patients. A total of 20 eyes were thus included. Four eyes (20%) did not respond to treatment during the first week. One additional eye failed at the 6 month visit. The treatment was successful in 15 eyes (75%) at 12 months. The IOP was significantly lower throughout follow-up (p < 0.01). At 12 months, the mean percentage of IOP reduction in the 15 respondent eyes was 22.1% and 12 eyes (60%) had IOP reduction higher than 20%. During the first two postoperative days, one eye with pigmentary glaucoma experienced a significant increase of flare associated with an IOP spike (34 mm Hg) that was controlled with systemic drugs; afterwards it qualified as a respondent and completed the study. No increase of flare was found in any other patient. No peripheral anterior synechiae formed.

Conclusions

In this case series, MDLT was effective in reducing IOP in 75% of medically insufficiently controlled OAG eyes without significant complications. This justifies randomized clinical studies to compare MDLT with current IOP lowering strategies.

Pattern of intraocular pressure reduction following laser trabeculoplasty in open-angle glaucoma patients: comparison between selective and nonselective treatment

OBJECTIVE

To compare the pattern of intraocular pressure (IOP) reduction following selective laser trabeculoplasty (SLT) versus argon laser trabeculoplasty (ALT) in open-angle glaucoma (OAG) patients, and to investigate the ability of initial IOP reduction to predict mid-term success.

METHODS

A prospective, nonrandomized, interventional case series was carried out. Consecutive uncontrolled OAG glaucoma patients underwent SLT or ALT; the same preoperative medical regimen was maintained during follow-up. Data collected included age, type of OAG, pre- and postoperative IOP, number of glaucoma medications, and surgical complications. Post-treatment assessments were scheduled at day 1 and 7 and months 1, 3, and 6.

RESULTS

A total of 45 patients (45 eyes) were enrolled [SLT group (n = 25); ALT group (n = 20)]. Groups were similar for age, baseline IOP, and number of glaucoma medications (P ≥ 0.12). We found no significant differences in mean IOP reduction between SLT (5.1 ± 2.5 mmHg; 26.6%) and ALT (4.4 ± 2.8 mmHg; 22.8%) groups at month 6 (P = 0.38). Success rates (IOP ≤ 16 mmHg and IOP reduction ≥25%) at last follow-up visit were similar for SLT (72%) and ALT (65%) groups (P = 0.36). Comparing the pattern of IOP reduction (% of IOP reduction at each visit) between groups, we found a greater effect following SLT compared with ALT at day 7 (23.7% ± 13.7% vs 8.1% ± 9.5%; P < 0.001). No significant differences were observed at other time points (P ≥ 0.32). Additionally, the percentage of IOP reduction at day 7 and at month 6 were significantly correlated in the SLT group (R(2) = 0.36; P < 0.01), but not in the ALT group (P = 0.89). Early postoperative success predicted late success in most SLT cases (82%). No serious complications were observed.

CONCLUSION

Although mid-term results suggest SLT and ALT as effective and equivalent alternatives, a greater initial IOP reduction was observed following SLT. In addition, the initial IOP reduction was a good predictor of mid-term success in patients undergoing SLT, but not ALT.

Inflammation assessment after selective laser trabeculoplasty (SLT) treatment

PURPOSE

Selective laser trabeculoplasty (SLT) appears to be a safe and effective method to lower intraocular pressure (IOP). The exact mechanism of action for reducing IOP and inflammation levels is not known. The aim of this study was to assess inflammation after SLT treatment.

METHODS

Forty patients (80 eyes) were included in the study.

INCLUSION CRITERIA

Glaucoma (pigmentary and pseudoexfoliative glaucoma)/ocular hypertension patients that will be treated with SLT in just one eye, both with and without eye-drops.

EXCLUSION CRITERIA

patients suffering from ocular or systemic inflammatory diseases are treated with cortisone or immunosuppressive drugs. Inflammation was measured in two different ways: (i) clinically with a slit lamp and classified 0-4; (ii) objectively with a 'Laser flare meter (Kowa FM 500)'. Measurements were taken before SLT, 2 hr, 1 week and 1 month after SLT treatment, both eyes were evaluated. IOP was also checked in the same way. SLT treatment was performed in 90°.

RESULTS

Inflammation before and after SLT showed no significant difference measured clinically with slit lamp and objectively with the laser flare meter among the groups. No inflammation or IOP reduction was found in the untreated eyes. No IOP spikes after SLT treatment were found.

CONCLUSION

Selective laser trabeculoplasty treatment seems not to induce inflammation in the anterior chamber when 90° was treated. SLT effectively and safely lowers IOP and might be considered as primary therapy.

Diode laser trabeculoplasty in open angle glaucoma: 50 micron vs. 100 micron spot size

The study was aimed at evaluating the efficacy of diode laser trabeculoplsaty in lowering intraocular pressure in patients with both primary open-angle glaucoma and exfoliation glaucoma by using different size of laser spot. This six-month, unmasked, controlled, prospective study included sixty-two patients with the same number of eyes, who were divided into two groups. Trabeculoplasty was performed with 50 micron and 100 micron laser spot size in the group I and group II, respectively. Other laser parameters were the same for both groups: the wave length of 532 nm, 0.1 second single emission with the power of 600-1200 mW was applied on the 180 degrees of the trabeculum. The mean intraocular pressure decrease in the 50 micron group (group 1) on day 7 was 24% from the baseline and after six-month follow-up period the intraocular pressure decrease was 29.8% (p < 0.001). In the 100 micron group (group II), the mean intraocular pressure decrease on day 7 was 26.5% and after six months it was 39% (p < 0.001).

Impact of laser trabeculoplasty on Trabectome® outcomes

BACKGROUND AND OBJECTIVE

To report the impact of prior laser trabeculoplasty on clinical outcomes of Trabectome (NeoMedix Corporation, Tustin, CA) surgery.

PATIENTS AND METHODS

This is a retrospective, non-comparative study of consecutive cases of Trabectome surgery with 36 months of follow-up. Main outcome measures were intraocular pressure (IOP), number of glaucoma medications, and the occurrence of secondary procedures.

RESULTS

In the trabeculoplasty group, mean IOP measured 16.5 +/- 4.0 mm Hg with an average decrease of 24% from preoperative IOP at 12 months. In eyes without previous trabeculoplasty, IOP measured 15.7 +/- 3.0 mm Hg with an average decrease of 30% at 12 months. Adjunctive medications decreased to 2.1 and 1.5 glaucoma medications, respectively. Secondary procedures were performed in 12% and 10% of eyes in each group.

CONCLUSION

Previous laser trabeculoplasty does not appear to significantly impact IOP, but may increase the need for glaucoma medication in patients undergoing Trabectome surgery.

Update on laser trabeculoplasty

Newer techniques of Laser Trabeculoplasty have revived the procedure and gained widespread acceptance by the ophthalmic community. This review was undertaken to address the evolution of different laser trabeculoplaty techniques, proposed mechanisms of action as well as review current studies of the therapeutic effects of these interventions.

Selective laser trabeculoplasty for primary angle closure with persistently elevated intraocular pressure after iridotomy

PURPOSE

To determine whether selective laser trabeculoplasty (SLT) can lower intraocular pressure (IOP) in eyes with chronic primary angle closure, elevated IOP, and a patent iridotomy.

PATIENTS AND METHODS

Patients with chronic angle closure who had underwent iridotomy, had an IOP greater than 21 mm Hg and a gonioscopically visible pigmented trabecular meshwork for at least 90 degrees were enrolled. SLT was applied to open angle segments. Duration of follow-up was 6 months.

RESULTS

Sixty eyes of 60 patients were enrolled. The mean baseline IOP was 24.6+/-2.5 mm Hg. At 6 months, IOP reduction of > or =3 mm Hg or 4 mm Hg was measured in 82% and 72% of eyes, respectively, and IOP reduction of > or =20% or 30% was measured in 54% and 24% of eyes, respectively. When only eyes that were treated with the same number or fewer medications were considered, these IOP reductions were measured in 67%, 58%, 43%, and 15%, respectively. During the study period 1 eye (1.7%) required trabeculectomy owing to IOP elevation shortly after the SLT. There were no other significant complications attributable to SLT.

CONCLUSIONS

SLT seems to be a safe and effective method of reducing IOP in many eyes with primary angle closure and a patent iridotomy in which there is a sufficient extent of visible trabecular meshwork.

[Effectiveness and relevance of laser trabeculoplasty: treatment of open-angle glaucoma]

Laser trabeculoplasty is a common glaucoma therapy that is safe and effective for reducing intraocular pressure. It was developed as a treatment for open-angle glaucoma in the 1970s, and larger studies proved its effectiveness in the years that followed. In recent years, through the implementation of newer processes such as selective laser trabeculoplasty, laser trabeculoplasty has experienced further developments. Because it causes less damage to the trabecular meshwork, it should have fewer adverse effects, making it a repeatable treatment. Studies on the indications, contraindications, and effectiveness of this method in lowering intraocular pressure are reviewed.

[Laser trabeculoplasty: therapeutic options and adverse effects]

Laser trabeculoplasty is a simple method for treating glaucoma and ocular hypertension and has few adverse effects. There are different laser systems for reducing the intraocular pressure of patients with glaucoma and ocular hypertension. Complications include transient intraocular pressure elevation, iritis, and anterior synechiae.

Repeat selective laser trabeculoplasty

PURPOSE

To evaluate the efficacy of repeat 360-degree selective laser trabeculoplasty (SLT) in glaucoma patients with prior successful 360-degree SLT.

DESIGN

Retrospective chart review.

METHODS

Forty-four eyes of 35 patients, > or =18 years of age, with open-angle glaucoma (primary open-angle, pseudoexfoliation, or pigmentary glaucoma), uncontrolled on maximum tolerable medical therapy, underwent an initial 360-degree SLT (SLT1), which was successful for > or =6 months, but eventually lost efficacy and was followed by a repeat 360-degree SLT (SLT2). Patients with prior argon laser trabeculoplasty or other glaucoma surgery, before or during the study period, were excluded. Intraocular pressure (IOP) measurements were recorded before each procedure and 1 to 4 weeks, 1 to 3 months, and 5 to 8 months posttreatment and 15 to 21 weeks after the initial SLT.

RESULTS

Reduction in IOP after SLT1 and SLT2 was significantly less with repeat treatment at 1 to 3 months, with average decreases of -5.0 and -2.9 mm Hg, respectively (P=0.01), but there were no statistically significant differences between treatments at the other equivalent time points. Using a definition of "success" as > or =20% peak IOP reduction, success rates for SLT1 and SLT2 were not significantly different. There was also no significant difference in eyes that received SLT2 6 to 12 months after SLT1 compared with those that received SLT2 12 months or more after SLT1.

CONCLUSIONS

Our findings suggest that repeat 360-degree SLT may be safe and effective after an initially successful 360-degree SLT has failed. These results may be achieved as early as 6 months after the first treatment.

Intraocular pressure reduction in the untreated fellow eye after selective laser trabeculoplasty

OBJECTIVE

To investigate the effect of selective laser trabeculoplasty (SLT) on the intraocular pressure (IOP) of untreated fellow eyes in patients with open-angle glaucoma.

STUDY DESIGN

Retrospective chart review.

PATIENTS AND METHODS

Charts of all patients who underwent SLT at the University of Texas Southwestern Medical Center at Dallas between September 2003 and May 2006 were reviewed. Each patient had IOP measurements by Goldmann applanation tonometry in both eyes preoperatively, and at 1 hour, 2 weeks, 3 months, and 6 months postoperatively. Patient age, gender, diagnosis, central corneal thickness (CCT), previous intraocular surgeries, and degrees of laser treatment were tabulated for each patient. Patients with a history of previous glaucoma surgery in either eye were excluded as were those who underwent any change in glaucoma medications or further laser or surgical intervention in either eye within 6 months of SLT. Data were analyzed using a paired two-tailed t-test, an unpaired two-tailed t-test, ANOVA, and linear regression.

RESULTS

A total of 43 patients were included through 6 months of follow-up. Mean reduction in IOP in the treated eye was 3.9 +/- 0.6 mmHg or 18.8% (p < 0.001) at final exam. Mean IOP reduction in the fellow untreated eye was 2.1 +/- 0.5 mmHg or 11.2% (p < 0.01). Patients with higher preoperative IOPs had a greater reduction in IOP in both eyes (p < 0.001 for treated eyes, and p = 0.02 for untreated eyes). Patients who were on a larger number of glaucoma medications preoperatively had a greater response in both eyes (treated eye p = 0.002, untreated eye p = 0.008). There was no significant difference in IOP response in either eye based on age, gender, CCT, degrees of treatment, or phakic status.

CONCLUSIONS

SLT produces a sustained and statistically significant IOP reduction in the fellow untreated eyes of patients with open-angle glaucoma. The results of our study support a biological mechanism of action for SLT. Limitations of this study include its retrospective design, relatively small sample size, a possible effect of increased compliance with medical therapy following SLT, and an inherent bias of excluding patients who underwent a change in medications or further laser or surgical therapy during the period under review.

Argon laser trabeculoplasty versus selective laser trabeculoplasty

The clinical role of laser trabeculoplasty remains a controversial topic with many different opinions. In the following three viewpoints the authors have taken contrasting positions on whether argon laser trabeculoplasty remains the "gold standard" or has been supplanted by selective laser trabeculoplasty. Questions are raised regarding the position of laser trabeculoplasty within the stepping of the treatment paradigm for open-angle glaucoma. The appropriate use of laser trabeculoplasty at different stages of disease severity is analyzed. A broader perspective with new insights on laser trabeculoplasty from these articles will hopefully lead to a better understanding of its clinical role in practice.

Severe iritis and choroidal effusion following selective laser trabeculoplasty

A patient with uncontrolled primary open-angle glaucoma underwent selective laser trabeculoplasty and developed a significant anterior chamber reaction, shallow anterior chamber, and choroidal effusion. Common complications associated with selective laser trabeculoplasty include conjunctival injection, mild anterior chamber reaction, and post-treatment intraocular pressure elevation. The authors believe this is the first reported case of severe iritis and choroidal effusion following selective laser trabeculoplasty.

Selective laser trabeculoplasty retreatment after prior argon laser trabeculoplasty: 1-year results

BACKGROUND

Argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT) are treatments for open-angle glaucoma. Many patients have previously received ALT but could benefit from further treatment. The purpose of this study was to examine whether SLT provided clinical benefit for patients who had previously received complete argon treatment.

METHODS

This was a prospective, partially randomized, comparison study. The study compared the effect after 1 year of SLT in patients with open-angle glaucoma (primary, pigmentary, or pseudoexfoliation) who had previously received 360 degrees of ALT with the effect of laser treatment (ALT or SLT) given for the first time in patients with this condition. Ninety-six subjects were given 180 degrees of laser trabeculoplasty. When both eyes qualified for treatment, the first eye treated was included in the analysis. Twenty-seven subjects were treated with SLT after previously receiving 360 degrees of ALT therapy; the remainder were given their first laser treatment, 30 being randomly assigned by coin toss to receive SLT and 39 to receive ALT.

RESULTS

The mean intraocular pressure (IOP) before treatment was 21.5 mm Hg (SLT after ALT), 22.9 mm Hg (SLT), and 22.0 mm Hg (ALT), with no statistical difference among the groups (p > 0.05). The mean IOP at 1 year was 16.7 mm Hg (SLT after ALT), 17.1 mm Hg (SLT), and 16.4 mm Hg (ALT). The IOP for all 3 groups was statistically significantly lower than at baseline (p < 0.001), but there were no differences among the groups in this respect (p > 0.05). At 1 year, the percentage IOP reductions from baseline were 23% (SLT), 19.3% (SLT after ALT), and 24% (ALT). There were no differences among the groups in the number of medications used before the laser, although there was a small but statistically significant decrease in the number of medications used before or after the laser treatment in both the SLT and the SLT after ALT group, but not the ALT group.

INTERPRETATION

SLT retreatment can produce a clinically useful decrease in IOP at 1 year, similar to that obtained by ALT, in patients who have had prior argon laser treatment. SLT may be a useful adjunctive therapy when 360 degrees of ALT has already been performed.

Mechanisms of action and efficacy of argon laser trabeculoplasty and selective laser trabeculoplasty

PURPOSE OF REVIEW

Since the 1980s, laser trabeculoplasty has served as an effective way to lower intraocular pressure in patients with primary or secondary open angle glaucomas, both as an initial therapy or in conjunction with hypotensive medications. This manuscript will describe the proposed mechanisms of action of argon laser trabeculoplasty and selective laser trabeculoplasty, as well as review current studies of the therapeutic effect of these interventions.

RECENT FINDINGS

The exact mechanisms by which argon laser and selective laser trabeculoplasty lower intraocular pressure are not known. There are several theories, however, and we discuss the three most common ones: the mechanical theory, the cellular (biologic) theory, and the cell division theory. Since both lasers are applied to the same tissue and produce similar results, they most likely produce their effects in comparable ways. We also describe the results of several studies comparing these devices. Most show them to be equally effective at lowering intraocular pressure; however, there are a few circumstances when selective laser trabeculoplasty may be a better option than argon laser trabeculoplasty.

SUMMARY

Argon laser and selective laser trabeculoplasty are safe and effective procedures for lowering intraocular pressure. The results of ongoing clinical trials will help further define their role in the management of patients with open angle glaucoma.

Laser trabeculoplasty trends with the introduction of new medical treatments and selective laser trabeculoplasty

PURPOSE

To correlate trends of laser trabeculoplasties (LTPs) with the introduction of medical therapies for glaucoma and to assess whether these trends changed after the introduction of selective laser trabeculoplasty (SLT) in 2001.

METHODS

A retrospective analysis of LTP numbers, filtration surgeries, glaucoma medications dispensed, and population distribution by age in Ontario, Canada, between April 1992 and March 2005.

RESULTS

The number of LTP per 1,000 persons estimated to have primary open angle glaucoma (POAG) increased from 138.05 in 1992 to a maximum of 149.23 in 1996 (8.1% increase, 1.96% annual increase) and then steadily decreased to 70.65 in 2001 (47.3% decrease, 14% annual decrease). From 2001 to 2004, the LTP rate increased to 162.54 (230% increase, 32% annual increase). The number of filtration surgeries per 1,000 persons estimated to have POAG steadily decreased from 1996 to 2004 by 21.42% (2.4% annual decrease). The number of glaucoma medications dispensed in Ontario increased from 1992 to 2004 by 91.5% (10.5% annual increase). There were no significant correlations between the LTP rates and the new glaucoma medications rates (r=-0.35 to 0.09; P=0.34 to 0.82) or filtration surgeries rates (r=0.007; P=0.98).

CONCLUSIONS

There was a substantial reduction in the number of LTP between 1997 and 2001 coinciding, but not correlated with the introduction of medications for the treatment of glaucoma. Between 2002 and 2004 the LTP rates increased, coinciding with the introduction of SLT.

Selective laser trabeculoplasty versus argon laser trabeculoplasty: results from a 1-year randomised clinical trial

AIMS

To compare selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT), in terms of intraocular pressure (IOP) lowering, in patients with open-angle glaucoma.

METHODS

176 eyes of 152 patients were enrolled in this study, 89 in the SLT and 87 in the ALT groups. Patients were randomised to receive either SLT or ALT treatment to 180 degrees of the trabecular meshwork. Patients were followed up to 12 months after treatment. The main outcome measured was IOP lowering at 12 months after treatment, compared between the SLT and ALT groups.

RESULTS

No significant difference (p = 0.846) was found in mean decrease in IOP between the SLT (5.86 mm Hg) and ALT (6.04 mm Hg) groups at 1 year or at any other time points, nor were there any significant differences in the rate of early or late complications between the two groups.

CONCLUSIONS

SLT is equivalent to ALT in terms of IOP lowering at 1 year, and is a safe and effective procedure for patients with open-angle glaucoma.

Projected cost comparison of selective laser trabeculoplasty versus glaucoma medication in the Ontario Health Insurance Plan

BACKGROUND

The projected 6-year cost comparison of primary selective laser trabeculoplasty (SLT) versus primary medical therapy in the treatment of open-angle glaucoma for Ontario patients aged 65 years or more is presented. Costs are taken from the perspective of the Ontario Health Insurance Plan at a per-patient level.

METHODS

The cost of each medication was obtained from the 2003 Ontario Drug Benefits formulary. The average annual cost of medications was determined by estimating the provincial prescription rate of glaucoma medications, with reference to both a volume-per-bottle study of these drugs and a study of pharmacy claims reports. A representative provincial prescription rate was calculated by reviewing 707 patient charts selected randomly from 5 ophthalmologic practices across Ontario. Medication therapies were categorized into mono-, bi-, and tri-drug therapy groups. The cost of SLT was analyzed under the following 2 scenarios. SLT rep 2y assumed a duration of 2 years before repeat SLT was necessary. SLT rep 3y assumed a duration of 3 years before repeat SLT was necessary. Bilateral 180 degrees SLT treatment and repeatability of SLT was assumed. The cost of surgery for patients who fail SLT or medical therapy was not accounted for in this study nor was the cost of patients who required medical therapy in conjunction with SLT.

RESULTS

In the SLT rep 2y scenario, the use of primary SLT over mono-, bi-, and tri-drug therapy produced a 6-year cumulative cost savings of 206.54 dollars, 1668.64 dollars, and 2992.67 dollars per patient, respectively. In the SLT rep 3y scenario, the use of primary SLT over mono-, bi-, and tri-drug therapy produced a 6-year cumulative cost savings of 580.52 dollars, 2042.82 dollars, and 3366.65 dollars per patient, respectively.

INTERPRETATION

Our findings suggest that SLT as primary therapy, at a per-patient level, offers a modest potential cost saving over primary medical therapy in the management of open-angle glaucoma for Ontario patients aged 65 years or more.

Hyphema Occurring During Selective Laser Trabeculoplasty

The first case of hyphema occurring during selective laser trabeculoplasty in an eye without neovascularization is described. A 77-year-old man with uncontrolled open-angle glaucoma received selective laser trabeculoplasty in both eyes for high intraocular pressure with maximally tolerated medical treatment. Hyphema occurred during selective laser trabeculoplasty in the left eye. This resolved spontaneously without sequelae. Successful intraocular pressure control was achieved. Hyphema and bleeding can happen during selective laser trabeculoplasty. Although this was transient and uneventful in one patient, careful monitoring of intraocular pressure and anterior chamber reaction is advised.

Baseline IOP predicts selective laser trabeculoplasty success at 1 year post-treatment: results from a randomised clinical trial

BACKGROUND/AIMS

The efficacy and safety of selective laser trabeculoplasty (SLT) has been found to be equivalent to argon laser trabeculoplasty (ALT). Since SLT produces significantly less disturbance to the trabecular meshwork and is theoretically more repeatable than ALT, it has potential to replace ALT as the standard procedure to treat medically uncontrolled open angle glaucoma. This study's objective is to determine factors that predict successful SLT at 1 year post-treatment.

METHODS

As part of a randomised clinical trial comparing the efficacy and safety of SLT to ALT, data on 72 SLT patients were collected, and successful SLT defined as having an SLT induced intraocular pressure (IOP) reduction of >or=20% at 1 year post-treatment follow up.

RESULTS

43 out of the 72 patients who had completed their 1 year follow up visit had an IOP reduction of >or=20% from baseline. No glaucoma risk factors studied predicted successful SLT. The amount of trabecular meshwork pigmentation was not a significant predictor. However, it was discovered that baseline IOP strongly predicted SLT success (odds ratio=1.16; p=0.0001).

CONCLUSION

SLT success was significantly predicted by baseline IOP but not by age, sex, other glaucoma risk factors, type of open angle glaucoma, or by degree of trabecular meshwork pigmentation.

High Failure Rate Associated With 180?? Selective Laser Trabeculoplasty

PURPOSE

To determine the efficacy of selective laser trabeculoplasty (SLT) in a tertiary care referral center.

PATIENTS AND METHODS

In this retrospective study of selective laser trabeculoplasty performed by five physicians, 94 eyes from 94 patients were included. A majority (83/92, 90%) underwent 180 degrees selective laser trabeculoplasty. Selective laser trabeculoplasty failure was defined in two ways: (1) IOP decrease <3 mm Hg (definition one), or (2) IOP decrease <20% (definition two), on two successive visits > or =4 weeks after SLT.

RESULTS

Overall failure rates were 68% (64/94) and 75% (70/94) (by definitions one and two, respectively). By survival/life-table analysis, mean time to failure was 6 months and 5.5 months, by definitions one and two, respectively. By the end of the study (14.5 months), the failure rates were 86% and 92% by definitions one and two, respectively. By each definition, in both univariable and multivariable analysis, only lower baseline IOP was a significant predictor of failure.

CONCLUSIONS

Selective laser trabeculoplasty had an overall low success rate in our tertiary clinic population, with overall failure rates of 68% to 74% in those who underwent 180 degrees selective laser trabeculoplasty.

Glaucoma lasers: a review of the newer techniques

PURPOSE OF REVIEW

This paper serves to review the safety and efficacy of new laser techniques for the treatment of glaucoma with emphasis on those studies published within the past year.

RECENT FINDINGS

Recently published studies have reinforced the strong safety profile, and efficacy of selective laser trabeculoplasty (SLT). Endoscopic photocoagulation, while more technically challenging and more invasive, offers several advantages over transcleral cyclophotocoagulation including direct observation of treatment and therefore, fewer complications. Laser goniopuncture is a fledgling technology with, thus far, a good safety profile, and benefits that include conjunctival sparing and good treatment response. Many unanswered questions remain including long-term success rates and ideal treatment parameters.

SUMMARY

The benefits of laser in the treatment of glaucoma have been well established, and while some techniques will add to the ophthalmologists' armamentarium, others will fall into disuse as the efficacy and safety profiles of these procedures become recognized. Novel laser modalities, as well as the more traditional ones, require continued evaluation to further refine treatment parameters and to determine their long-term benefits.