Comparison of the efficacy and safety of selective laser trabeculoplasty in cases with primary open-angle glaucoma and pseudoexfoliative glaucoma

Long-term follow-up of laser trabeculoplasty in multi-treated glaucoma patients

PURPOSE

To evaluate the long-term effect of laser trabeculoplasty (LTP) in patients randomized to multi-treatment in the Glaucoma Intensive Treatment Study (GITS).

METHODS

Patients with untreated newly diagnosed open-angle glaucoma were treated with three intraocular pressure (IOP)-lowering substances for 1 week and then 360° argon or selective LTP was performed. IOP was measured just before LTP and repeatedly during the 60-month study period. Our previous report on 12 months follow-up data revealed no effect of LTP in eyes having an IOP <15 mmHg before the laser treatment.

RESULTS

Before LTP, the mean IOP ± standard deviation in all 152 study-eyes of 122 multi-treated patients was 14.0 ± 3.5 mmHg. Three eyes of three deceased patients were lost to follow-up during the 60 months. After exclusion of eyes that received increased therapy during follow-up, the IOP was significantly reduced at all visits up to 48 months in eyes with pre-LTP IOP ≥15 mmHg; 2.6 ± 3.1 mmHg at 1 month and 1.7 ± 2.8 mmHg at 48 months, n = 56 and 48, respectively. No significant IOP reduction was seen in eyes with pre-LTP IOP <15 mmHg. Seven eyes, i.e., <13%, with pre-LTP IOP ≥15 mmHg at baseline had required increased IOP-lowering therapy at 48 months.

CONCLUSION

LTP performed in multi-treated patients may provide a useful IOP reduction that is maintained over several years. This was true on a group level when the initial IOP was ≥15 mmHg, but if the pre-laser IOP was lower than that, chances of LTP success were small.

Selective laser trabeculoplasty: A review

Glaucoma is the second most prevalent cause of blindness worldwide, and the only effective management is the lowering of intraocular pressure (IOP). Selective laser trabeculoplasty (SLT) has become an essential part of glaucoma management since its commercial release in 2001. It has been an improvement from the previous argon laser trabeculoplasty (ALT), by using 1% of the laser energy, reducing the amount of anterior segment inflammation and minimising the degree of mechanical injury to the trabecular meshwork. There is now a large volume of work that demonstrates SLT is equally effective as ALT and topical medication in lowering IOP. It is simple to perform, with a well described side-effect profile, and is long-lasting and repeatable. This review will summarise the current literature on SLT for each of these topics.

Selective Laser Trabeculoplasty in the Treatment of Ocular Hypertension and Open-Angle Glaucoma: Clinical Review

Selective laser trabeculoplasty (SLT) is a glaucoma treatment that reduces intraocular pressure (IOP). Its mechanism is based on the biological effects of the selective application of laser energy to pigmented trabecular meshwork (TM) cells, resulting in increased outflow facility. Herein, we review current publications on SLT and summarize its efficacy and safety for different indications in open-angle glaucoma (OAG) and ocular hypertension (OHT) treatment. SLT effectively reduces IOP when used as a primary treatment. In patients whose IOP is medically controlled, SLT helps to reduce medication use, and when maximally tolerated topical therapy is ineffective, SLT facilitates the realization of the target IOP. SLT is a repeatable procedure for which the vast majority of complications are mild and self-limiting. With effective IOP reduction, low complication rates and the potential to repeat the procedure, SLT offers the possibility of delaying the introduction of medical therapy and other more invasive treatment modalities while simultaneously avoiding the accompanying complications. With this knowledge, we suggest that SLT be considered as an essential primary treatment option in OAG and OHT, switching to other treatment modalities only when laser procedures are insufficient for achieving the required target IOP.

Selective laser trabeculoplasty in exfoliative glaucoma eyes with prior argon laser trabeculoplasty

PURPOSE

To explore the efficacy of selective laser trabeculoplasty (SLT) within eyes with exfoliative glaucoma and history of prior argon laser trabeculoplasty (ALT).

METHODS

A single-centre trial consisting of 47 patients (47 eyes) with uncontrolled exfoliative glaucoma. The main outcome measure was intraocular pressure (IOP) reduction 3 and 9 months after SLT. Treatment success was defined as reduction from the preoperative IOP by 20% and 2 mmHg (<12 mmHg), 3 mmHg (12-16 mmHg) or 4 mmHg (>16 mmHg) depending on the baseline IOP.

RESULTS

Patient age was 79.3 ± 7.6 years (mean ± SD) and gender distribution 15 males and 32 females. The mean pre-SLT IOP was 15.6 ± 5.1 (range 9-28) mmHg, and mean number of glaucoma drugs 2.0 ± 1.2. The mean interval between prior ALT and SLT was 44.0 ± 36.9 (range 11-137) months. After SLT, the mean IOP change was -2.7 ± 4.2 mmHg (-14.8 ± 23.5%) at 3 months, and -2.8 ± 3.5 mmHg (-16.3 ± 19.4%) at 9 months. Pre-SLT IOP correlated with the IOP reduction at 3 months (r = 0.530, p < 0.001) and at 9 months (r = 0.432, p = 0.007). The overall success rate was 50% at 3 months, and 42% at 9 months. At both 3 and at 9 months, the cut-off level for treatment success was achieved when preoperative IOP was 18 mmHg and above. IOP lowering effect of SLT did not correlate with the number of glaucoma drugs, age, gender or use of prostaglandin inhibitors. Neither postoperative iritis nor other adverse effects were documented during the follow-up.

CONCLUSIONS

Selective laser trabeculoplasty is a safe and noteworthy treatment option to reduce IOP in exfoliative glaucoma eyes, especially with pre-SLT IOP over 18 mmHg.

Evaluation of intraocular pressure in the first 24hours after micropulse laser trabeculoplasty in eyes with pseudoexfoliation glaucoma

PURPOSE

To evaluate the immediate 24-hour effect on intraocular pressure (IOP) of a single session of micropulse laser trabeculoplasty (MLT) in patients with pseudoexfoliation glaucoma (PEXG).

PATIENTS AND METHODS

In this single-center, one-arm, prospective study, patients with PEXG on prostaglandin analogue monotherapy with inadequate IOP control were treated with 360-degree 532nm MLT. Intraocular pressure was evaluated at 1, 4, 8, 12 and 24hours after MLT. Twenty-three eyes of eighteen patients (10 male, 8 female) were enrolled in the study.

RESULTS

The mean age of the patients was 71.83±6.51 years, and the mean IOP prior to MLT was 20.61±1.8mmHg. The mean IOP was reduced by 2.17±3.31mmHg, 2.69±3.85mmHg, 0.87±3.02mmHg, 2.13±2.8mmHg and -0.87±3mmHg at 1, 4, 8 and 24hours after MLT, respectively. At 4 and 12hours after MLT, the mean IOP was statistically significantly lower compared to the pre-MLT IOP (P=0.043 and P=0.021 respectively). No eye experienced an IOP spike≥5mmHg during the first 24hours after MLT.

CONCUSION

Treatment with MLT in PEXG eyes did not result in any significant, potentially dangerous IOP spikes during the first 24hours after MLT.

A Review of the Clinical Usefulness of Selective Laser Trabeculoplasty in Exfoliative Glaucoma

In the last decade, selective laser trabeculoplasty (SLT) has been commonly used in the management of several different types of glaucoma, as either primary or adjunct therapy. The technique has an excellent safety profile and is at least as effective as argon laser trabeculoplasty. Although the actual mechanism of action of SLT remains unclear, evidence has shown that it does not induce morphologically evident trabecular meshwork alterations. SLT's non-disruptive mode of action offers the advantage of repeatability. Exfoliation glaucoma (XFG) is a secondary open-angle glaucoma with unfavorable intraocular pressure (IOP) characteristics, which typically carries a poorer long-term prognosis than primary open-angle glaucoma. Consequently, patients with XFG often need multiple medications to achieve IOP levels that prevent disease progression. Because complicated pharmacotherapy regimens undermine the long-term tolerability and compliance of patients with XFG, options such as SLT may decrease the burden of multiple therapies and ultimately improve prognosis. In fact, SLT may be a particularly attractive option in XFG because the pigment-laden trabecular tissue of these patients enhances the absorption of laser energy and thus augments the biologic effects induced by this treatment. The current article reviews the postulated mechanisms of action of SLT, discusses practical aspects of SLT therapy, and examines selected peer-reviewed literature pertaining to the clinical usefulness of this modality in XFG patients.

Laser Management of Glaucoma in Exfoliation Syndrome

Argon laser trabeculoplasty as well as selective laser trabeculoplasty can be used in patients with exfoliation syndrome with similar safety and efficacy. However, treatment effect may abruptly reverse and patients need to be followed regularly to monitor intraocular pressure control. Newer laser treatment modalities including micropulse laser trabeculoplasty, titanium sapphire laser trabeculoplasty and pattern scanning trabeculoplasty show promising results but need to be studied in exfoliation patients. For exfoliation patients with angle closure, peripheral iridectomy, iridoplasty or cataract extraction can be very helpful. For refractory exfoliation glaucoma, transscleral diode laser cyclophotocoagulation offers a reasonable option to lower intraocular pressure. Other approaches to cyclophotocoagulation such as micropulse transcleral diode laser need to be studied further in exfoliation patients.

Corneal topographic alterations after selective laser trabeculoplasty

PURPOSE

To investigate the presence of corneal alterations in the long term among patients with primary open-angle glaucoma (POAG) after a single session of selective laser trabeculoplasty (SLT) treatment.

MATERIALS AND METHODS

The files of the POAG patients who had been treated with SLT were evaluated retrospectively. The Pretreatment Scheimpflug corneal topographic (SCT) findings were then compared with the post-treatment findings.

RESULTS

The files of 33 patients were eligible. The changes in central corneal thickness, thinnest point of cornea, and posterior corneal asphericity at 5 and 8 mm were statistically significant (p = 0.03, 0.01, 0.02, and 0.04 respectively). On the other hand, the simulated K, anterior 3 mm K, anterior 5 mm K, posterior 3 mm K, posterior 5 mm K, anterior asphericity at 3 mm, posterior asphericity at 3 mm, and Zernike values did not change significantly following the treatment (p = 0.19, 0.08, 0.1, 0.3, 0.2, 0.75, 0.09, and 0.3 respectively).

CONCLUSION

SLT can slightly alter pretreatment SCT findings in 3-6 months. Clinicians should wait for at least 6 months after SLT before performing any subsequent surgeries that depend on corneal parameters.

Selective laser trabeculoplasty in patients with pseudoexfoliative glaucoma vs primary open angle glaucoma: a one-year comparative study

AIM

To compare the efficacy of single-session 360-degree selective laser trabeculoplasty (SLT) for reduction of intraocular pressure (IOP) in patients with pseudoexfoliative glaucoma (PXFG) and primary open angle glaucoma (POAG).

METHODS

This is a single-center, prospective, nonrandomized comparative study. Patients older than 18 years of age with uncontrolled PXFG or POAG eyes requiring additional therapy while on maximally tolerated IOP-lowering medications were included. The primary outcome measure changed in IOP from baseline. Success was defined as IOP reduction ≥20% from baseline without any additional IOP-lowering medication. All patients were examined at 1d, 1wk, 1, 3, 6, 9, 12mo after SLT.

RESULTS

Nineteen patients (20 eyes) with PXFG and 27 patients (28 eyes) with POAG were included in the study. In the visual fields mean deviation was -2.88 (±1.67) in the POAG and -3.1 (±1.69) in the PXFG groups (P=0.3). The mean (±SD) IOP was 22.9 (±3.7) mm Hg in the POAG group and 25.7 (±4.4) mm Hg in the PXFG group at baseline and decreased to 18.4 (±3.2) and 18.0 (±3.9) mm Hg in the POAG group (P<0.001 and P=0.02), and to 17.9 (±4.0) and 21.0 (±6.6) mm Hg in the PXFG group (P<0.001 and P=0.47) at 6 and 12mo, respectively. The number of medications was 2.6 (±0.8) in the POAG group and 2.5 (±0.8) in the PXFG group at baseline, and did not change at all follow-up visits in both groups (P=0.16 in POAG and 0.57 in PXFG). Based on Kaplan-Meier survival analysis, the success rate was 75% in the POAG group compared to 94.1% in the PXFG group (P=0.08; log rank test) at 6mo, and 29.1% and 25.0% at 12mo, respectively (P=0.9; log rank).

CONCLUSION

The 360-degree SLT is an effective and well-tolerated therapeutic modality in patients with POAG and PXFG by reducing IOP without any change in number of medications. The response was more pronounced early in the postoperative period in patients with PXFG whereas there was no statistically significant difference at 12-month follow-up.

Selective Laser Trabeculoplasty: An Update

Selective laser trabeculoplasty (SLT) is an effective treatment option for the reduction of intraocular pressure (IOP) in patients with ocular hypertension or open-angle glaucoma. The mechanism by which SLT lowers IOP is not completely understood and is likely multifactorial. Published studies indicate that SLT is at least as effective as argon laser trabeculoplasty or medications at lowering IOP in many forms of glaucoma. In addition to IOP reduction, SLT may decrease IOP fluctuation and can be successfully used as primary or adjunctive therapy for the management of both early and advanced glaucoma. However, SLT may not be effective in certain forms of glaucoma, and the IOP-lowering effect seems to wane with time. High pretreatment IOP is the strongest predictor of treatment success, even in patients with normal-tension glaucoma. Repeatability of SLT has been controversial, but recent evidence suggests that it can be successfully repeated to achieve additional or recurrent IOP reduction, even in eyes that only had a modest response to initial treatment. Adverse events are uncommon after SLT, and the most common complications such as discomfort and inflammation are typically mild and transient. Further investigation is required to determine the optimal treatment parameters for SLT treatment. Limited evidence suggests that SLT is cost-effective as primary therapy for patients with glaucoma.

Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma: A Review of the Literature with Updates on Surgical Management

Pseudoexfoliation syndrome (PES) is a systemic disorder caused by progressive accumulation of extracellular material over various tissues. PES usually determines increased intraocular pressure, changes in the anatomical aspects of the optic nerve, and visual field alterations leading to the diagnosis of pseudoexfoliation glaucoma (PEG). Use of topical medical treatment usually leads to poor results in terms of long-term follow-up but many surgical techniques, such as Argon Laser or Selective Laser Trabeculoplasty, have been proposed for the management of PEG affected patients. The present paper is a review on the pseudoexfoliation syndrome and pseudoexfoliation glaucoma with an update on surgical management.

Selective laser trabeculoplasty as a first-line therapy: a review

Poor adherence with glaucoma medications has been well documented. There remains a significant unmet need for a relatively safe intraocular pressure (IOP)-lowering procedure that minimizes or eliminates patient participation, and thus reduce the incidence of treatment failures attributable to nonadherence. Selective laser trabeculoplasty (SLT) offers several advantages: It effectively reduces IOP in most patients with open-angle glaucoma, it is cost-effective compared with eye drops, it can be repeated if needed, and it eliminates the issue of adherence to medications when used as an initial treatment. This article reviews the evidence supporting the use of SLT as a first-line therapy in glaucoma.