Long-term outcomes of selective laser trabeculoplasty (SLT) treatment in pigmentary glaucoma patients

Intraocular pressure profile following selective laser trabeculoplasty in pigmentary and primary open-angle glaucoma

PURPOSE

To compare the intraocular pressure (IOP) profile and the incidence of IOP spikes following selective laser trabeculoplasty (SLT) between pigmentary glaucoma (PG) and primary open-angle glaucoma (POAG).

MATERIALS AND METHODS

Retrospective comparative study of 65 PG eyes of 51 patients matched with 65 POAG eyes of 65 patients who received SLT. Matching was done based on age, gender, glaucoma severity, pre-laser IOP, and number of medications. Post-SLT IOP spike was defined as IOP elevation ≥5mmHg, 30-45 min after the laser.

RESULTS

In PG and POAG groups, the average age was 62.33 ± 9.18 and 62.58 ± 9.19 years (p = 0.95). The glaucoma severity (p = 0.708), baseline IOP (PG = 21.61 ± 1.34mmHg vs. POAG = 21.13 ± 5.09mmHg, p = 0.943), and number of topical glaucoma medications(PG = 2.34 ± 1.34 vs. POAG = 2.1 ± 1.41, p = 0.342) were comparable. More PG patients were on oral acetazolamide (PG = 26.15% vs. POAG = 1.5%, p < 0.001). Average logMAR visual acuity was significantly higher in the POAG group (0.207 ± 0.3 vs. 0.192 ± 0.37, p = 0.012). Eyes with PG received lower laser energy (POAG = 63.65 ± 22.03 mJ vs. PG = 43.71 ± 25.68 mJ, p < 0.001). IOP spikes were recorded in 5 PG eyes (7.6%) and none in the POAG group (p = 0.058). Failure rates were similar (PG = 50.7% and POAG = 43.1%, p = 0.205). In multivariable analysis, only pre-laser IOP (coefficient = 2.154 [CI: 0.765-3.543], p = 0.003) was a significant predictor of IOP change percentage after 12 months.

CONCLUSIONS

SLT was comparably effective in both PG and POAG. IOP spikes were observed only in the PG group, though the total laser energy was lower in this group compared with POAG.

Selective laser trabeculoplasty: An updated narrative review

Selective laser trabeculoplasty (SLT) has experienced a resurgence in interest, primarily driven by promising findings from the Laser in Glaucoma and Ocular Hypertension Trial. By offering SLT as an initial drug-free treatment option, we may be able to thwart issues such as adherence and persistence that plague our current medical management protocols. In this comprehensive narrative review, we delve into the current body of literature that explores the utility of SLT across a wide spectrum of scenarios and glaucoma subtypes. We present evidence that provides valuable insight into the efficacy and benefits of SLT, positioning it as a viable option in the management of glaucoma. Careful consideration of the associated risks and challenges is also necessary for successful adoption into clinical practice. Despite the ample evidence supporting SLT's efficacy, some questions remain regarding its long-term effects and the potential need for retreatment. This review aims to shed light on these aspects to guide clinicians in making informed decisions and tailoring treatment plans to individual patient needs. This review also provides the readers with a bird's eye view of the potential impact of SLT and adds clarity to the various therapeutic protocols that one can follow to ensure optimal clinical outcomes for our patients.

Pigment dispersion syndrome and pigmentary glaucoma: overview and racial disparities

Pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) are two stages within the same ophthalmic disease spectrum, which are known to be affected by race. The prevalence of PDS is underestimated, largely due to its minor clinical symptoms. Although the prevalence of PG is low, the visual impairment associated with PG is extremely severe. The prevalence of PDS-PG is four or more times higher in Caucasians than in Blacks or Asians, and the "classic" PDS in Caucasians has long been used as a benchmark diagnostic criterion. Following extensive research focused on African Americans and Asians, the standard for diagnosing PDS-PG was refined. At the same time, the pathogenesis of PDS is not the same in different races. Hence, the effectiveness of preventive treatment and the need for treatment may not be equivalent in different races. The rate of conversion of PDS to PG is nearly 1/3 in Caucasians and higher in blacks and Asians, requiring more aggressive treatment and monitoring. We systematically searched a PubMed database from inception to March 2022 to provide an overview of research progress in various aspects of PDS-PG. Specifically, this paper considers the effects of race on disease prevalence, clinical manifestation, diagnostic criteria, disease mechanism, hereditary traits, treatment, and prevention to provide an accurate and comprehensive guide for the diagnosis and treatment of PDS-PG in various races.

[Secondary open-angle glaucoma: pseudoexfoliative glaucoma, pigmentary glaucoma and neovascular glaucoma]

Secondary open-angle glaucomas are a heterogeneous group of diseases in which a variety of pathophysiological mechanisms result in an elevation of intraocular pressure. This article is the first part of a review of the more common forms of secondary open-angle glaucomas. The pathogenesis, characteristic clinical findings and treatment of pseudoexfoliative glaucoma, pigmentary glaucoma and neovascular glaucoma are discussed. An emphasis is placed on the differences in treatment compared to primary open-angle glaucoma and prophylactic treatment approaches are explained where possible.

[Pigmentary glaucoma: yesterday, today, tomorrow]

Pigment dispersion syndrome (PDS) is a condition that mostly affects young men with myopic refraction. PDS is characterized by the presence of Krukenberg spindle, peripheral iris defects, significant trabecular meshwork pigmentation, as well as convex iris configuration. Such configuration can cause friction of iris's posterior pigment layer on its ligaments, which leads to the release of pigment and its accumulation mostly in the structures of the anterior chamber. Over time PDS can progress into pigmentary glaucoma (PG), which in turn can lead to permanent loss of vision. This review analyzes available data on diagnosis and treatment of PDS and PG.

Selective laser trabeculoplasty lowered the untreated fellow eye long-term intraocular pressure: a 3-year observational study

To explore the long-term intraocular pressure (IOP)-lowering effect of monocular selective laser trabeculoplasty (SLT) in the untreated fellow eyes of open-angle glaucoma (OAG) patients. This was a retrospective observational study. Consecutive Chinese OAG patients who received monocular SLT treatment were included in this study. One hundred and eighty degree SLT was conducted as adjunctive treatment when anti-glaucoma medication was not sufficiently effective after clinical evaluation. Treatment success was defined as more than 20% IOP reduction of the baseline IOP levels. IOP-decreasing amplitude and SLT success rate of both eyes were investigated during the 3-year follow-up period. Age, gender, baseline IOP levels, number of medications, and SLT energy parameters were analyzed to determine its influence on IOP reduction effect and treatment success rate. A total of 32 Chinese OAG patients were included in this study and 25 of them completed the 3-year follow-ups. Their pretreatment IOPs were 18.85 ± 2.81 mmHg in the treated eyes and 17.38 ± 2.37 mmHg in the fellow eyes. At the 3-year follow-up visits, IOP decreased to 2.76 ± 3.72 mmHg (14.16%) in the treated eyes and 2.16 ± 2.73 mmHg (11.95%) in the fellow eyes, with a success rate of 47.83% (11 in 23 cases) and 44.00% (11 in 25 cases), respectively. IOPs of both eyes decreased significantly after SLT from 6 months and lasted to 3 years after treatment. Baseline IOP level was positively correlated with IOP reduction in the treated eyes and other factors were not correlated with IOP reduction and treatment success. Monocular SLT treatment as adjunctive treatment could lower IOPs not only in the treated eyes but also in the untreated eyes in poor medication-controlled OAG patients. In addition, its IOP reduction effect could last to 3 years after treatment in clinical practice.

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.

Outcomes of selective laser trabeculoplasty in corticosteroid-induced ocular hypertension and glaucoma

PURPOSE

To report the outcomes of selective laser trabeculoplasty (SLT) in lowering intraocular pressure (IOP) in patients with steroid-induced ocular hypertension and glaucoma.

METHODS

A retrospective chart review of patients who underwent SLT for steroid-induced ocular hypertension or glaucoma between January 2014 and October 2018. Success of SLT was defined as ⩾20% IOP reduction from baseline without further medical or surgical intervention and/or a reduction in the number of glaucoma medications by ⩾1 from baseline while maintaining the target IOP. Main outcome measures were change in IOP from baseline and reduction in the number of medications post-laser.

RESULTS

A total of 25 eyes of 17 patients were included in the study. The mean duration of follow-up was 18.8 ± 4.5 months. IOP decreased from 23.7 ± 6.7 mmHg pre-laser to 14.4 ± 3.2 mmHg post-laser, at the last follow-up visit (p < 0.001). The mean number of medications was 1.8 ± 1.6 medications pre-laser and 1.4 ± 1.3 medications post-laser (p = 0.262). The overall success rate at 12 months was 72%. No visually significant complications were encountered during the whole duration of follow-up.

CONCLUSION

SLT is a safe and effective procedure that can result in well-controlled IOP in patients with steroid-induced ocular hypertension and glaucoma.

Pigmentdispersionssyndrom

Das Pigmentdispersionssyndrom ist eine Erkrankung, die durch Abschilferung von Pigment aus dem Irispigmentepithel und dessen Ablagerung im vorderen Augenabschnitt charakterisiert ist. Typisch ist eine Trias aus Ablagerungen am Hornhautendothel, zirkulären Iristransilluminationen und einer Pigmentierung des Trabekelwerks. Das Spektrum reicht vom einfachen Pigmentdispersionssyndrom bis zum Pigmentdispersionsglaukom mit Optikusatrophie.

[Pigment Dispersion Syndrome]

Pigment dispersion syndrome (PDS) is a disorder predominantly affecting young, myopic adults. It is characterised by the liberation of pigment of the iris and deposition of it on various structures of the anterior segment leading to multiple specific findings in slit lamp examination. Typical alterations are a deposition of pigment on the central corneal endothelium, circular iris transillumination defects in the mid periphery, a posterior bowing of the iris and increased pigmentation of the trabecular meshwork. Findings are usually bilateral symmetric. Posterior bowing of the iris causes rubbing of the pigmented iris epithelium against lens structures like zonular fibres with a consecutive liberation of pigment. Trabecular meshwork changes because of pigment deposition reduce aqueous outflow facility with the risk of elevated intraocular pressure and glaucoma. Pigmentary glaucoma (PG) is a secondary open angle glaucoma. Treatment of PG is similar to primary open angle glaucoma, including medical therapy, laser therapy and surgery. Peripheral laser iridotomy was shown to change iris configuration but its efficacy in the prevention of PG has not been confirmed in the literature. The purpose of this paper is to summarize information regarding ocular manifestations of PDS to facilitate an early diagnosis and to present a general view of the treatment of PG.

Pigment dispersion syndrome and its implications for glaucoma

Pigment dispersion syndrome (PDS) represents a clinical spectrum of a relatively common and usually underdiagnosed phenomenon produced by spontaneous pigment dispersion from the iris into the anterior segment. PDS is often bilateral, has no gender predisposition, and presents at a young age, particularly in myopes. Although most patients experiencing an episode of pigment dispersion are asymptomatic, extreme photophobia, ocular pain, redness, and blurred vision may occur. Other characteristic signs are iridolenticular contact, concave iris configuration, 360° peripheral iris transillumination, and pigment deposition on the anterior chamber angle or the corneal endothelium (Krukenberg spindle). Early PDS diagnosis is crucial to detect patients with pigment-related ocular hypertension (POHT) that can eventually lead to pigmentary glaucoma (PG). The latter represents a sight-threatening condition in which mechanical, environmental, and genetic factors contribute to optic nerve damage. In this review, we update the pathogenic mechanisms involved in the clinical spectrum of the disease. We describe its clinical presentation, ophthalmologic manifestations, and complications, including the factors influencing the development of POHT and PG. Because PDS has variable clinical presentations that lead to misdiagnoses, we emphasize the differential diagnosis and the actual therapeutic strategies according to disease status.

Canaloplasty in Pigmentary Glaucoma: Long-Term Outcomes and Proposal of a New Hypothesis on Its Intraocular Pressure Lowering Mechanism

This study presents the long-term results on canaloplasty in a group of patients affected by pigmentary glaucoma, and studies the progression of the disease after surgery. Material and methods: Twenty-nine eyes of 25 patients with pigmentary glaucoma in maximum tolerated medical therapy with significant visual field damage progression underwent canaloplasty and were followed up to 11 years (mean 59.8 ± 30.1 months). All patients underwent a complete ophthalmic examination every 6 months. Results: The pre-operative mean intraocular pressure (IOP) was 31.8 mmHg ± 10.9 (range 21–70) with an average of 3.3 medications. After 1, 2, 3, and 4 years, the mean IOP was 15.9 ± 4.0, 14.4 ± 7.3, 14.1 ± 2.1, and 15.7 mmHg, respectively, with 0.4, 0.5, and 0.7 medications, respectively. Four patients underwent trabeculectomy after 3 to 30 months due to uncontrolled IOP. Gonioscopy showed a significant reduction of pigment in trabecular meshwork in all cases, starting from the sixth month. In some cases, the pigment was almost completely reabsorbed after two years, suggesting an accelerated transit and escape of the granules through the trabecular spaces. Conclusions: Canaloplasty seems to be a reasonable option in treating patients affected by progressive pigmentary glaucoma. The reabsorption of pigment granules from the trabecular meshwork could, at least in part, explain the relatively high success rate observed after this surgical procedure.

Pigment dispersion syndrome and pigmentary glaucoma: a review and update

INTRODUCTION

Pigment dispersion syndrome (PDS) is a condition where anomalous iridozonular contact leads to pigment dispersion throughout the anterior segment and the released pigment is abnormally deposited on various ocular structures.

CLINICAL PRESENTATION

The clinical presentation of PDS is defined by the presence of pigmented cells on the corneal endothelium, an increase of pigmentation of the trabecular meshwork, and mid-periphery transillumination defects of the iris. This syndrome, more common in myopes, is usually bilateral and can be associated with ocular hypertension or glaucoma. Secondary open-angle pigmentary glaucoma (PG) can develop due to reduction of the outflow of aqueous humour and consequent increase in intraocular pressure leading to glaucomatous optic neuropathy. Diagnosis of PG is commonly between 40 and 50 years of age, occurring more frequently in men. The advent of ultrasound biomicroscopy and anterior segment optical coherence tomography has contributed to enhancing our knowledge on the condition. Typical alterations of the anterior segment are the posterior insertion of the iris and iris concavity. Treatment of PG should be initiated early to hinder disease progression, glaucomatous damage, and vision loss. Management is based on medical therapy, laser iridotomy, selective laser trabeculoplasty, and filtration procedures.

CONCLUSIONS

The differential diagnosis of PDS with other disorders can be challenging and awareness of the condition together with meticulous ophthalmologic examination allows early diagnosis followed by appropriate management strategies. The present review is a comprehensive report on the clinical characteristics, pathogenesis, current management, and status quo of PDS and PG.

Selective laser trabeculoplasty: past, present, and future

Over the past two decades, selective laser trabeculoplasty (SLT) has increasingly become an established laser treatment used to lower intraocular pressure in open-angle glaucoma and ocular hypertensive patients. In this review we trace the origins of SLT from previous argon laser trabeculoplasty and review the current role it has in clinical practice. We outline future directions of SLT research and introduce emerging technologies that are further developing this intervention in the treatment paradigm of glaucoma.

Update on pigment dispersion syndrome and pigmentary glaucoma

PURPOSE OF REVIEW

The present article reviews the clinical features and pathogenesis of pigment dispersion syndrome and pigmentary glaucoma and provides an update regarding their diagnosis and management.

RECENT FINDINGS

Newer imaging modalities including ultrasound biomicroscopy and anterior segment optical coherence tomography facilitate visualization of the iris concavity characteristic of eyes with pigment dispersion syndrome and pigmentary glaucoma. Patients with pigmentary glaucoma may be distinguished from those with other glaucoma types by the presence of typical symptoms, personality type, and patterns of diurnal intraocular pressure fluctuation. Although laser iridotomy has been shown to alter iris anatomy in pigmentary glaucoma, it is not proven to slow visual field progression. Multiple trials have validated the safety and efficacy of filtering surgery in treating pigmentary glaucoma, with fewer studies published on the role of micro-invasive glaucoma surgery.

SUMMARY

Literature from the review period has further defined the unique clinical characteristics of pigment dispersion syndrome and pigmentary glaucoma. Laser surgery has a limited role in the management of these entities, whereas trabeculectomy remains an acceptable first-line surgical treatment. Further studies are needed to define the potential application of the newer micro-invasive glaucoma procedures in pigmentary glaucoma.

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.

[Selective laser trabeculoplasty: results after a first and a second session, overall comparison and results for three indications]

PURPOSE

To compare the results obtained with SLT trabeculoplasty after an initial treatment (SLT-1) and after a second treatment (SLT-2). Subgroup analysis according to trabecular pigmentation and the existence of a high myopia.

MATERIALS AND METHODS

Retrospective study of 77 patients, 152 SLT sessions performed in the Ophthalmology Department of Clermont-Ferrand University Medical Center, 118 SLT-1, 34 SLT-2. Three comparable groups of patients were assembled: group 1 (glaucoma patients with normal or subnormal trabecular pigmentation), group 2 (glaucoma patients with high myopia), and group 3 (glaucoma patients with significant trabecular pigmentation). The results were compared between groups, for SLT-1 and SLT-2.

RESULTS

Intraocular pressure lowering was consistent with data reported in the literature. Comparison of the results of SLT-1 versus SLT-2 did not find any significant difference in terms of IOP change. However, after SLT-2, the IOP response appears significantly greater (P=0.03) in the group with significant trabecular pigmentation compared to the non-myopic group with normal trabecular pigmentation.

DISCUSSION

Our results are consistent with the literature for efficacy, tolerance and reproducibility of SLT. No reduction in SLT efficacy was observed after a second session. Trabecular pigmentation is not a predictor of the response after the first session. In the case of retreatment (SLT-2), the differences observed lead to the hypothesis that it may be appropriate to perform at least two SLT treatments in patients with significant trabecular pigmentation in order to obtain maximal effect. Myopia, a variable not previously studied, does not seem to influence SLT outcomes.

CONCLUSION

Trabecular pigmentation and the presence of myopia do not appear to be predictive of a successful first treatment. However, our study leads us to suggest the hypothesis that the maximal response of SLT in patients with significant trabecular pigmentation is not obtained until after at least two sessions. This observation opens an interesting perspective on the therapeutic strategy to adopt in the case of pigmentary glaucoma.