Predictors of success in selective laser trabeculoplasty for chinese open-angle glaucoma

The Impact of Baseline Intraocular Pressure on Initial Treatment Response in the LiGHT Trial: Selective Laser Trabeculoplasty versus Medication

PURPOSE

The Laser in Glaucoma and Ocular Hypertension Trial demonstrated the efficacy and safety of selective laser trabeculoplasty (SLT) compared with topical hypotensive medication as first-line therapy for ocular hypertension and open-angle glaucoma. This substudy explored the impact of pretreatment (baseline) intraocular pressure (IOP) on treatment response.

DESIGN

Post hoc analysis of randomized control trial data.

PARTICIPANTS

A total of 1146 eyes from 662 patients were included in this analysis: 559 eyes in the SLT group and 587 in the medication group.

METHODS

Intraocular pressure reduction at 8 weeks after treatment with either SLT or prostaglandin analog (PGA) eye drops was assessed at different levels of baseline IOP, and the groups were compared. Differences in absolute and percentage IOP lowering between SLT and PGA groups were tested with a linear mixed-effects model. Differences in the probability of achieving ≥ 20% IOP lowering between SLT and PGA groups, at different levels of baseline IOP, were estimated using a logistic mixed-effects model.

MAIN OUTCOME MEASURE

Intraocular pressure-lowering response to SLT versus PGA eye drops.

RESULTS

Mean IOP was not significantly different between the groups at baseline or 8 weeks after treatment initiation. Both treatments showed greater IOP lowering at higher baseline IOP and less IOP lowering at lower baseline IOP. Selective laser trabeculoplasty tended to achieve more IOP lowering than PGA drops at higher baseline IOP. Prostaglandin analog drops performed better at lower baseline IOP, and the difference compared with SLT, in terms of percentage IOP reduction, was significant at baseline IOP of ≤ 17 mmHg. A significant difference was found in the relationship between baseline IOP and probability of ≥ 20% IOP lowering between the two treatments (P = 0.01), with SLT being more successful than PGA at baseline IOP of more than 22.5 mmHg.

CONCLUSIONS

We confirm previous reports of greater IOP lowering with higher baseline IOP for both SLT and PGA drops. In treatment-naïve eyes, at higher baseline IOP, SLT was more successful at achieving ≥ 20% IOP lowering than PGA drops. At lower baseline IOP, a statistically greater percentage, but not absolute, IOP lowering was seen with PGA drops compared with SLT, although the clinical significance of this is uncertain.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Selective laser trabeculoplasty is safe and effective in patients previously treated with prostaglandin analogs: An evidence-based review

PURPOSE

Prostaglandin analogs (PGAs) are first-line treatments for ocular hypertension (OHT) and open-angle glaucoma (OAG). However, frequent side effects and high costs hinder patient's compliance resulting in disease progression. Evidence suggests selective laser trabeculoplasty (SLT) may be considered a first-line treatment for OHT and OAG due to its safety profile, minor side effects, and reduced costs. Considering that PGAs and SLT share action mechanisms, it is hypothesized that previous PGA therapy may affect subsequent SLT efficacy. Therefore, we analyzed if PGAs reduce SLT efficacy.

METHODS

An evidence-based review was performed to assess the safety and efficacy of SLT in patients previously treated with PGAs. For this purpose, we performed an extensive literature search using the National Library of Medicine's PubMed and Google Scholar database for all English language articles published until May 2021.

RESULTS

There is evidence of non-superiority of PGAs therapy versus SLT for OHT and OAG. A multicenter, randomized, observer-masked clinical trial (RCT) of untreated OHT and OAG patients concluded that SLT should be offered as the first-line treatment for these patients. This study was supported by a meta-analysis of RCTs, comparing SLT efficacy versus antiglaucoma drugs only, with the advantage of an SLT lower rate of adverse effects.

CONCLUSIONS

Cost-effectiveness, patient compliance, and antiglaucoma drugs' side effects, including higher surgical failure, favor consideration of SLT as first-line therapy for OAG and OHT. Furthermore, SLT efficacy does not seem to be affected by prior PGA administration; however, larger cohort, comparative, multicenter RCTs are necessary to answer this question.

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.

Outcome After Selective Laser Trabeculoplasty for Glaucoma Treatment in a Thai Population

Purpose

The study aimed to evaluate the efficacy and predictive factors of success after selective laser trabeculoplasty (SLT) for treating various types of open-angle glaucoma in a Thai population.

Design

The study employed a retrospective cohort design.

Materials and Methods

The study retrospectively recruited Thai subjects diagnosed with open-angle glaucoma receiving first time selective laser trabeculoplasty. Primary open-angle glaucoma (POAG), ocular hypertension (OHT) and other types of open-angle glaucoma were included. Reduced intraocular pressure (IOP) of 20% or decreased number of antiglaucoma drugs usage after SLT was defined as success. Various parameters were analyzed for association with SLT success.

Results

Ninety-six eyes were recruited in the study. Mean pre- and postSLT IOP were 19.31±3.59 and 15.04±3.13 mmHg, respectively. IOP decreased significantly in all follow-up visits (p<0.001). Overall, 59.4% met the treatment endpoint. More than 10% postSLT IOP elevation at 1 hour was the only covariate positively associated with SLT success in both univariate (odds ratio (OR) = 1.042, p = 0.037) and multivariate analyses (OR = 1.040, p = 0.046). Underlying hypertension and preSLT IOP were negatively associated with SLT success in both univariate (OR = 0.970, p = 0.026, OR = 0.955, p < 0.001) and multivariate analysis (OR = 0.970, p = 0.026, OR = 0.991, p < 0.001).

Conclusion

IOP significantly decreased as well as the number of antiglaucoma drugs needed after SLT. More than 10% postSLT IOP elevation at 1 hour was a positive predictor whereas systemic hypertension and preSLT IOP were negative predictors of SLT success.

Responsiveness to ripasudil may be a potential outcome marker for selective laser trabeculoplasty in patients with primary open-angle glaucoma

We examined responsiveness to ripasudil as a potential factor for predicting the effect of selective laser trabeculoplasty (SLT) when performed for primary open-angle glaucoma (POAG). A total of 70 eyes with no history of glaucoma surgery underwent SLT between January 2015 and June 2019. Patients were divided into two groups, with an intraocular pressure (IOP) decrease of 15% or more due to ripasudil administration before SLT defined as the effective group, while an IOP decrease of less than 15% was defined as the non-effective group. Kaplan–Meier survival analysis was performed. A Cox proportional hazards model assessed the influence of baseline factors on the success. Of the 70 eyes evaluated, treatments were effective in 22 and non-effective in 48. Postoperatively, both groups exhibited IOP reductions for up to 24 months. Success ratios at 12 and 24 months after SLT were 43.5% and 18.5% in the effective versus 24.9% and 9.3% in the non-effective group, which were significantly higher in the effective group (P = 0.03). Presence of a ripasudil effective eye (P = 0.03) was associated with treatment success. Responsiveness to ripasudil may be useful in predicting the therapeutic effect of SLT.

Outcomes of pattern scanning laser trabeculoplasty and selective laser trabeculoplasty: Results from the lausanne laser trabeculoplasty registry

PURPOSE

To compare the long-term safety and efficacy of pattern scanning laser trabeculoplasty (PSLT) and selective laser trabeculoplasty (SLT).

METHODS

This was a retrospective database analysis (Lausanne Laser Trabeculoplasty Registry) of patients having had laser trabeculoplasty (LT) prior to 2017 with a minimum follow-up of 1 year. Inclusion criteria were age ≥40 years and diagnosis of ocular hypertension (OHT) and open-angle glaucoma (OAG). Selective laser trabeculoplasty (SLT) eyes were matched to PSLT eyes according to baseline intraocular pressure (IOP), baseline number of ocular hypotensive medications (OHM) and glaucoma diagnosis. Success was defined as an IOP ≤ 20% from baseline or an IOP equal or lower than baseline accompanied by a reduction in OHM. Multivariate regression models were used to study associations between success and baseline clinical parameters.

RESULTS

From 280 eyes in the database, 81 eyes had PSLT and were matched with 81 SLT eyes (162 patients). Mean age was 69.4 ± 12.1 years, and 56.2% were female. Mean IOP was 18.6 ± 5.3 and 18.2 ± 4.1 mmHg at baseline and 15.9 ± 3.0 and 16.0 ± 3.4 mmHg at 12 months and 15.2 ± 2.7 and 16.2 ± 3.4 mmHg at 24 months, for PSLT and SLT, respectively. 60.5% of PSLT and 65.4% of SLT eyes achieved treatment success (p = 0.20). Number of OHM was 1.0 ± 1.0 and 1.4 ± 1.2, respectively (p = 0.052). Baseline IOP (OR = 1.23, p < 0.01) and number of OHM (OR = 1.67, p < 0.01) were associated with success in both PSLT and SLT, while LT modality was not [OR = 0.81 (0.43-1.53), p = 0.52], and a diagnosis of primary OAG was negatively associated (OR = 0.42, p = 0.04).

CONCLUSION

Our study did not find any significant differences between PSLT and SLT in terms of safety and efficacy in patients with OHT and glaucoma. Baseline IOP was associated with higher success rates in both procedures. Additional studies are needed to evaluate the outcomes of PSLT in non-Caucasian populations and the ability of repeat PSLT to achieve additional IOP reduction.

Outcome of Selective Laser Trabeculoplasty in Young Patients with Primary Open-Angle Glaucoma and Ocular Hypertension

Purpose

To determine the effectiveness and safety of selective laser trabeculoplasty (SLT) in young patients with primary open-angle glaucoma (POAG) and ocular hypertension (OHT).

Methods

This was a retrospective clinical study. Fifty-six eyes from 56 young (age ≤ 40 y) patients with POAG or OHT treated with SLT were included. According to age, patients were divided into group 1 and group 2. Patients in group 1 were younger than 18 years old, and patients in group 2 were between 18 and 40 years old. Patients were evaluated before treatment and at 1 hour, 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year after treatment. We also collected older patients (age ≥ 60 y) who received SLT during the same period for comparison at 1-year follow-up. Possible factors affecting the success of SLT, including baseline IOP, age, sex, diagnosis (POAG or OHT), and whether or not use of antiglaucoma medication before treatment, were analyzed.

Results

SLT treatment produced significant reduction in IOP in the young patients with POAG or OHT during the 1-year follow-up period（P < 0.05）. Mean IOP at 1 hour after SLT was lower in group 1 than in group 2 (P < 0.01), but at other follow-up time points, IOP values were not different (P > 0.05). IOP reduction and success rate were not significantly different between young and old patients at 1 year after treatment. IOP measurements over a 24-hour period were recorded before and after the SLT in 20 young adult patients. IOP values were significantly lower in the treated patients at all time points than at pretreatment (P < 0.05), and 24-hour mean IOP, peak IOP, valley IOP, and fluctuation in IOP were also lower in SLT-treated patients (P < 0.05). Baseline IOP was found as a predictor of SLT success in young patients (OR = 1.895, P=0.003), whereas age, gender, diagnosis, and whether or not use of antiglaucoma medication were not correlated with SLT success (P=0.725, P=0.750, P=0.061, and P=0.201, respectively).

Conclusion

In this study, SLT was found as an effective and safe treatment for young patients with POAG and OHT. High baseline IOP predicted high SLT success.

Comparison of the effects of 180° and 360° applications of selective laser trabeculoplasty on intraocular pressure and cornea

PURPOSE

To compare the effects of 180° and 360° selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) and cornea in patients with bilateral primary open-angle glaucoma.

METHODS

Fifty-two eyes of 26 patients were included. On the same day, 180° SLT (Group 1) was applied to one eye of patients and 360° SLT (Group 2) to the other eye. IOP values were compared at pre-SLT and post-SLT 1 day, 1 week, 1, 3, and 6 months. Changes in central corneal thickness (CCT) and endothelial cell count (ECC) were examined.

RESULTS

In groups, significant decreases were observed in IOP at 1 week (p < 0.05), 1, 3, and 6 months (p < 0.001). No significant difference was determined between group 1 and 2 in IOP-lowering effectiveness or success rates (p > 0.05). There was no significant difference in CCT at inter- or intragroup comparisons (p > 0.05). In group 1, no significant difference was determined in pre- and post-SLT ECC (p > 0.05). In group 2, significant decrease in ECC was observed at 1 week (p < 0.05). However, ECC returned to its initial levels at 1 month.

CONCLUSIONS

To the best of our knowledge, this is the first study in literature to compare different quadrant SLT applications performed on both eyes, on the same day, in the same patient group and to compare the effects of those applications on IOP and cornea. In reducing IOP, 180° and 360° SLT are similarly effective. These effects begin on the 1st week and persist for 6 months. Temporary corneal changes may be observed following 360° SLT.

Comparison of successful outcome predictors for MicroPulse® laser trabeculoplasty and selective laser trabeculoplasty at 6 months

Purpose: To identify and compare factors predictive of successful outcome for MicroPulse^® laser trabeculoplasty (MLT) and selective laser trabeculoplasty (SLT).

Methods: 50 MLT-treated eyes and 50 SLT-treated eyes of open-angle glaucoma patients were reviewed for baseline characteristics, pre- and postoperative IOP and medications, and adverse events including postoperative IOP elevation >5 mmHg (IOP spikes) through 6 months of follow-up. Success was defined as ≥20% IOP reduction or ≥1 medication reduction without additional IOP lowering procedures at 6 months follow-up.

Results: MLT and SLT had similar success rates (44% vs 40%, P=0.983). Older age predicted success for SLT (P=0.013) but not MLT (P=0.154). Both MLT and SLT led to greater IOP lowering in patients with baseline IOP >18 mmHg, but only for SLT did baseline IOP have a significant association with success (P=0.035 vs P=0.983). Number of laser shots was associated with success in MLT (P=0.031) but not in SLT (P=0.970). Glaucoma severity and pigmentation of the trabecular meshwork (PTM) were not associated with rate of success for either group. The rate of IOP spikes was significantly (P=0.022) higher in the SLT group (10%) compared to none in the MLT group. No other complications or visually significant adverse events occurred in either group.

Conclusion: Although MLT and SLT resulted in similar success rates, older age and higher baseline IOP predicted success for SLT while MLT was equally efficacious regardless of these factors. Glaucoma severity and PTM were not associated with success of either laser procedures. 10% of SLT patients experienced IOP spike post procedure, whereas none in the MLT group did. MLT may be a safer alternative to SLT that is effective in lowering IOP and need for medications for a wider variety of patients with open angle glaucoma.

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Treatment Outcomes and Prognostic Factors of Selective Laser Trabeculoplasty for Open-angle Glaucoma Receiving Maximal-tolerable Medical Therapy

PURPOSE

To evaluate the efficacy of selective laser trabeculoplasty (SLT) for patients with open-angle glaucoma receiving maximal-tolerable medical therapy.

PATIENTS AND METHODS

Consecutive patients with open-angle glaucoma who were followed up for at least 1 year after SLT were retrospectively evaluated. The effectiveness was assessed using Kaplan-Meier survival analysis with 2 criteria for failure: (1) intraocular pressure (IOP) equal to or more than baseline; and (2) <20% reduction from baseline, on 2 consecutive visits. Those 2 failure criteria also included loss of light perception, reoperation of SLT, and glaucoma surgery. Influence of baseline factors on success were assessed using mixed-effects Cox proportional hazard models.

RESULTS

Seventy-five eyes [39 primary open-angle glaucoma, 23 exfoliation glaucoma, and 13 secondary open-angle glaucoma (SOAG)] of 59 patients (21 females) aged 65.5±15.9 (mean±SD) were included. Preoperative mean IOP was 23.3±6.5 mm Hg with 3.4±1.3 IOP lowering medications. The overall success ratio at the end of study period was 45.3% by criterion 1 and 14.2% by criterion 2. The success ratio by criterion 1 and 2 was 61.1% and 21.7% in primary open-angle glaucoma, 29.3% and 14.5% in exfoliation glaucoma, and 15.4% and 7.7% in SOAG, respectively. Higher preoperative IOP and diagnosis of SOAG were significantly associated with treatment failure (P<0.01 and 0.04, respectively).

CONCLUSIONS

One-year efficacy of SLT in controlling IOP was very limited in patients with maximal-tolerable medical therapy. Types of glaucoma and preoperative IOP were significant prognostic factors for treatment success.

Comparing pattern scanning laser trabeculoplasty to selective laser trabeculoplasty: A randomized controlled trial

PURPOSE

To compare safety, tolerability and intraocular pressure (IOP)-lowering efficacy of pattern scanning laser trabeculoplasty (PSLT) with selective laser trabeculoplasty (SLT) in fellow eyes of untreated patients with glaucoma.

DESIGN

Randomized controlled trial.

PARTICIPANTS

Twenty-nine patients (58 eyes) with primary and secondary open angle glaucoma (OAG) were randomized to undergo PSLT or SLT in each eye.

METHODS

Pattern scanning laser trabeculoplasty was performed using the Pascal laser (Pascal Streamline 577; Topcon Inc., Tokyo, Japan). Patients' comfort level to treatment was assessed using a visual analogue scale (VAS). Follow-up visits were at week 1, month 1, 3 and 6. Success was defined as IOP reduction ≥20%.

MAIN OUTCOME MEASURES

Safety, tolerability and IOP reduction.

RESULTS

The mean age of patients was 54.1 ± 15.5 years. Baseline IOP was similar between both groups (PSLT, 17.3 ± 4.0 mmHg; SLT, 16.8 ± 3.6 mmHg, p > 0.05). In the PSLT group, the mean IOP at 1, 3 and 6 months was 14.2 ± 3.5, 13.9 ± 2.6 and 14.0 ± 2.7 mmHg, respectively. In the SLT group, the mean IOP at 1, 3 and 6 months was 14.4 ± 4.1, 13.7 ± 3.2 and 13.7 ± 3.1 mmHg, respectively. The IOP reduction in the PSLT group was greater than the SLT group at 1 month (p < 0.01) and 3 months (p < 0.01). VAS score was better in PSLT eyes: 23.9 ± 20.5 (range, 0-82) than in SLT eyes: 50.4 ± 25.3 (range, 0-98) (p < 0.001). No serious adverse events were recorded.

CONCLUSIONS

Both laser modalities had similar safety and efficacy profiles while PSLT was better tolerated by patients.

Selective laser trabeculoplasty in pseudophakic and phakic eyes: a prospective study

AIM

To compare the efficacy of selective laser trabeculoplasty (SLT) in replacing medical therapy in pseudophakic and phakic eyes.

METHODS

Subgroup of a prospective randomized clinical trial including patients with primary open angle glaucoma or ocular hypertension controlled with medication. Of 38 pseudophakic eyes were matched with 38 phakic eyes. SLT was offered as a way to decrease medication while maintaining the same low eye pressure. SLT was performed over 360°, at 3ns, spotsize 400 µm, 100 spots. Data [intraocular pressure (IOP), number of medications needed] were measured at 1h, 1wk, 1, 3, 6 and 12mo. An independent-samples t-test was performed to compare baseline characteristics of the phakic and the pseudophakic group and differences in evolution of mean IOP and number of used medications. Chi-squared analysis was performed to investigate proportions of fast, slow and non-responders.

RESULTS

The mean IOP measurement was 13.00± 2.88 mm Hg in the phakic group (38 eyes) and 13.51±3.06 mm Hg in the pseudophakic group (38 eyes) (P>0.05). This changed little after SLT and IOP lowering effect was comparable between the two groups. Main aim however was to lower the amount of medication needed. In the phakic group medication lowered from 1.29±0.62 at baseline, to 0.15±0.46 after 12mo; a reduction of 88.37%. In the pseudophakic group, used medication changed from 1.71±1.04, to 0.41±0.61; a 76.02% reduction. The differences were not statistically significant at any time point (P>0.05). IOP lowering occurred slightly faster in the pseudophakic group (50% of patients after one week) than in the phakic group (68% of patients after more than 4wk). The difference was not significant (P>0.05).

CONCLUSION

IOP lowering effect of SLT is comparable between phakic and pseudophakic eyes.

Correlation of Intraocular Pressure Between Both Eyes After Bilateral Selective Laser Trabeculoplasty in Open-angle Glaucoma

PURPOSE

To investigate the correlation of intraocular pressure (IOP)-lowering effects of selective laser trabeculoplasty (SLT) between the 2 eyes treated with SLT in open-angle glaucoma (OAG).

METHODS

This prospective cohort study sequentially recruited subjects with bilateral OAG. All subjects received a single session of 360-degree SLT treatment. Success was defined as IOP reduction of ≥20%. Spearman correlation was used to compare the following parameters between the 2 eyes following SLT: IOP at day 1, 1 week, and 1 month; percentage of success; and IOP reduction.

RESULTS

In 84 eyes of 42 subjects that received bilateral SLT treatment, both eyes had statistically comparable baseline characteristics. There were significant correlations between the IOP in both eyes at all time intervals following SLT as well as for the percentage of IOP reduction and the success rate at 1 month after SLT (all r≥0.7, P<0.0001). A total of 42.9% of subjects had bilateral success and 38.1% had bilateral nonsuccess with a significant correlation between both eyes in these 2 groups (Spearman r>0.6, P<0.02). Nineteen percent had success in 1 eye and nonsuccess in the fellow eye with an inverse correlation between the 2 eyes (Spearman r=-0.7, P=0.03).

CONCLUSION

There is a strong and significant correlation in the IOP-lowering response to SLT between both eyes in near 80% of treated OAG subjects, whereas near 20% had an asymmetrical and inverse response to SLT between both the eyes.

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.

MicroPulse Laser Trabeculoplasty for the Treatment of Open-Angle Glaucoma

The aim of the study was to investigate the safety and efficacy of using MLT in the treatment of open-angle glaucoma (OAG).This prospective cohort included subjects ≥18 years of age with OAG, defined as the open angle on gonioscopy with glaucomatous optic neuropathy evident from optical coherence tomography. Subjects with IOP < 21 mm Hg were classified as normal tension glaucoma and those with IOP ≥21 mm Hg were classified as primary open-angle glaucoma. Those with angle closure, secondary glaucoma, prior laser trabeculoplasty, use of systemic IOP-lowering medications, corneal pathologies, follow-up <6 months, recent intraocular surgery, or only 1 functional eye were excluded. A single session of unilateral MLT treatment was delivered using a 577 nm diode laser to 360° of the trabecular meshwork to reduce IOP or medication load. Medications were titrated up or down at 1 month after laser to achieve a 25% IOP reduction from presentation or an IOP <18 mm Hg, whichever was lower. The following were compared using the Repeated Measures ANOVA with Bonferroni's Multiple Comparison Test: IOP (on presentation, pre-MLT, day 1, 1 week, 1 month, 3 months, and 6 months after MLT) and the number of medications (pre-MLT, 3 months, and 6 months after MLT). After 6 months, responders with initial success to MLT (IOP reduction ≥20% at 1 month) received treatment in the fellow eye.In 48 subjects with OAG, the mean number of MLT shots applied was 120.5 ± 2.0 shots using a mean energy of 1000 mW per shot. Only 7.5% had a mild, self-limiting anterior uveitis postlaser with no change in the Snellen visual acuity at 6 months (P's > 0.5). The IOP and number of medications were significantly reduced at all time intervals following MLT compared to the pre-MLT level (P's < 0.0001). At 6 months, the IOP was reduced by 19.5% in addition to a 21.4% reduction in medication compared to pretreatment levels. The MLT success rate was 72.9%. During the first 6 months only 2.1% required a repeated laser trabeculoplasty.MLT was effective in reducing IOP and medications in OAG with minimal postlaser inflammation and low failure rate at 6 months following laser.

Optimal selective laser trabeculoplasty energy for maximal intraocular pressure reduction in open-angle glaucoma

PURPOSE

To identify the optimal energy level to be used in selective laser trabeculoplasty (SLT) for maximal intraocular pressure (IOP) reduction in open-angle glaucoma (OAG) patients.

PATIENTS AND METHODS

This cohort sequentially recruited OAG subjects in Hong Kong, China during 2011 to 2012. All subjects received a single session of SLT with near confluent spots to 360 degrees of the trabecular meshwork. An initial energy of 0.8 mJ was titrated until bubble formation was just visible. The main outcomes included: change in IOP (pre-SLT to 1 mo post-SLT) and total SLT energy (SLT spots multiplied by the mean energy). For statistical analysis, only the right eye of each subject was used. Bandwidth selection by generalized cross-validation was used to determine the optimal interval and point of total SLT energy that resulted in the largest IOP reduction.

RESULTS

A total of 49 Chinese OAG subjects had a mean age of 64.2±11.1 years. The pre-SLT IOP was 17.1±2.9 mm Hg while on 1.9±1.1 types of antiglaucoma eye drops. The mean total energy was 167.1±41.4 mJ (171.5±41.2 spots at 1.0±0.06 mJ). The 1 month post-SLT IOP was 13.5±2.8 mm Hg. The percentage of SLT success was 57.1% (28/49). The 95% confidence band by bootstrap method was plotted showing that a total energy between 214.6 and 234.9 mJ significantly decreased the IOP>25%, with the optimal total energy at 226.1 mJ.

CONCLUSIONS

A higher SLT energy, in the range of 214.6 to 234.9 mJ, seems to be associated with an improved IOP-lowering response. Further randomized control trials with treatment stratification are needed to confirm these results.

Two-Year Clinical Results After Selective Laser Trabeculoplasty for Normal Tension Glaucoma

This article aims to investigate the clinical results at 2 years after selective laser trabeculoplasty (SLT) for normal tension glaucoma (NTG). This prospective cohort study recruited NTG patients taking antiglaucoma medication. Subjects were excluded if they had previous glaucoma surgery/laser or corneal pathologies. All subjects underwent a 1-month washout. A single session of SLT was performed to 360° of the trabecular meshwork. Medication was resumed at 1 month to achieve a targeted 30% intraocular pressure (IOP) reduction from the post-washout/pre-SLT IOP. IOP was measured every 3 months and medication use was recorded at 3, 6, 12, and 24 months. Subjects with a secondary SLT or cataract extraction were excluded from IOP and medication analyses. At 24 months, 34 of the initial 45 right eyes were eligible for analyses. There were significant IOP reductions at all time intervals (except at 1 week) following SLT when compared to the prestudy (without medication) or pre-SLT (post-washout) IOP (P < 0.0001). Medications were likewise significantly reduced at all time intervals following SLT (P < 0.0001). At 24 months, the IOP was 11.5% lower than the prestudy IOP, 22.0% lower than the pre-SLT IOP, and medication use was reduced by 41.1% (P < 0.0001). Six out of 45 eyes (13.3%) required a secondary SLT. Absolute success (IOP reduction >20% from pre-SLT, without medication) was achieved in 11.1% (5/45). Reductions in IOP and medication use were evident at 2 years following SLT for the treatment of NTG whereas 11% remained medication free.

TRIAL REGISTRATIONS

The Clinical Trials Register of the University of Hong Kong HKCTR1847. The European Clinical Trials Database 2014-003305-15 (August 11, 2014).

Effects of timing of vitrectomy performed for open-globe injury patients on the thickness of retinal nerve fiber layer

Objective:

To study the effects of timing of vitrectomy performed for open-globe injury patients on the thickness of retinal nerve fiber layer (RNFL).

Methods:

A total of 120 patients with traumatic optic neuropathy (TON) were selected and divided into a treatment group and a control group by random draw (n=60). Vitrectomy was performed within one week upon injury for treatment group and after one week for control group. The thickness of RNFL was observed by optical coherence tomography.

Results:

All surgeries were conducted successfully, without severe complications. The best corrected visual acuity of treatment group surpassed that of control group one month after surgery, and treatment group had an obviously higher overall effective rate (95.0%) than control group did (81.7%). The incidence rate of postoperative complications in treatment group (6.7%) was significantly lower than that of control group (28.3%) (P<0.05). Logistic multivariate regression analysis showed that vitrectomy timing and postoperative complications were independent risk factors of prognosis (P<0.05). Both groups had significantly thinner RNFLs one week after surgery (P<0.05), and treatment group almost recovered within one month (P>0.05).

Conclusion:

Early vitrectomy effectively augmented the visual acuity of patients with TON, decreased complications, affected RNFL thickness reversibly, and improved prognosis.

Noninvasive glaucoma procedures: current options and future innovations

Noninvasive glaucoma procedures (NIGPs) represent a new dawn in the management of glaucoma. They try to fill the gap between the shortcoming of invasive glaucoma surgeries and antiglaucoma medications. NIGPs were introduced as an adjunct or alternative treatments for glaucoma. Some of these procedures have shown good efficacy with few serious complications. Hence, they are now used as both primary and adjunctive therapy for glaucoma. The most common NIGPS involve laser and ultrasound technologies. Currently, the portfolio of NIGPs includes argon laser trabeculoplasty, selective laser trabeculoplasty, and micropulse diode laser trabeculoplasty. More recent innovations include therapeutic ultrasound for glaucoma, ultrasonic circular cyclocoagulation, and deep wave trabeculoplasty.

Efficacy of selective laser trabeculoplasty for normal tension glaucoma: 1 year results

BACKGROUND

Normal tension glaucoma (NTG) is commonly treated with anti-glaucoma medications. Recently, selective laser trabeculoplasty (SLT) has been demonstrated to lower the intraocular pressure (IOP) and medication use in NTG. The purpose of this study was to investigate the efficacy of a single session of SLT for NTG at 1 year.

METHODS

This prospective cohort study recruited NTG patients taking anti-glaucoma medication. Potential subjects were excluded if they had had previous glaucoma surgery or laser and also if intraocular surgery or additional SLT procedures were performed after the first treatment. All subjects underwent a 1-month washout. A 30% IOP reduction was set as the target IOP. A single session of SLT was performed to 360 degrees of the trabecular meshwork. At 1-month after SLT, medication was resumed to achieve the target IOP. The IOP was measured every 3 months, and the number of medications was recorded at 3, 6, and 12 months. Only the right eye was used for statistical analysis.

RESULTS

In 41 right eyes, the mean pre-study IOP was 14.3 ± 3.4 mmHg while on 1.5 ± 0.8 eye drops. The post-washout IOP was 16.2 ± 2.2 mmHg. A mean of 191.1 ± 26.3 SLT shots at 1.0 ± 0.07 mJ were applied. There was significant IOP reduction at all time intervals following SLT when compared to the post-washout IOP (P < 0.0001). The number of medications was significantly reduced at all time intervals following SLT when compared to the pre-study level (P < 0.0001). At 12 months, the mean IOP was 12.2 ± 2.2 mmHg while on 1.1 ± 0.9 eye drops.

CONCLUSIONS

A single session of SLT for NTG achieved an additional 15% IOP reduction while using 27% less medication at 1 year compared to pre-study levels.

TRIAL REGISTRATION

The Clinical Trials Register of the University of Hong Kong HKCTR1847 The European Clinical Trials Database 2014-003305-15 (August 11, 2014) ( https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-003305-15 ).

Twenty-four-hour intraocular pressure related changes following adjuvant selective laser trabeculoplasty for normal tension glaucoma

To investigate intraocular pressure (IOP) related patterns before and after selective laser trabeculoplasty (SLT) for normal tension glaucoma (NTG).In this prospective cohort study, 18 NTG patients underwent SLT. Success was defined as IOP reduction ≥ 20% by Goldmann applanation tonometry. 24-hour IOP-related pattern recording with a contact lens sensor (CLS) (SENSIMED Triggerfish, Sensimed, Switzerland) was done before (baseline) and 1 month after SLT. A cosine function was fitted to the mean CLS patterns for each individual in the SLT success and non-success groups and the amplitude before and after SLT was calculated. Diurnal, nocturnal, and 24-hour CLS pattern local variability was determined for pre- and post-SLT sessions. Cosine amplitude and variability were compared before and after SLT by group using paired t-tests, with α = 0.05. Patients (11 women, 7 men) had a mean age of 65.1 ± 13.7 years. Mean IOP was 15.3 ± 2.2 mm Hg at baseline and was reduced by 17.0% to 12.7 ± 1.8 mm Hg 1 month after SLT (P = 0.001). SLT was successful in 8 patients (44%). The amplitude of the fitted cosine was reduced by 24.6% in the success group, but displayed an amplitude increase of 19.2% post-SLT in the non-success group. Higher diurnal local variability of the CLS pattern was observed after SLT in non-success subjects (P = 0.002), while nocturnal variability showed no significant change. The increase in diurnal variability in the non-success group led to an increase in 24-hour variability in this group (P = 0.001). No change in local variability (diurnal, nocturnal, and 24-hour) was seen in the success group. The IOP-related pattern cosinor amplitude was reduced in NTG patients with a successful SLT treatment whereas the non-success group exhibited an increase of cosine amplitude. Higher diurnal and 24-hour CLS pattern variability was observed in non-success patients 1 month post-SLT.

Predictors of success in selective laser trabeculoplasty for normal tension glaucoma

To determine the predictors of success for selective laser trabeculoplasty (SLT) in normal tension glaucoma (NTG). This prospective cohort study recruited subjects with unilateral or bilateral NTG on medication. All subjects received a single session of 360° SLT treatment. SLT success was defined as IOP reduction≥20% at 1-month. The following covariates were analyzed via univariate and multivariate analyses: age; sex; lens status; presenting, pre-SLT, and post-SLT IOP's; number and type of medications; SLT shots and energy; and pre-SLT investigations. In 60 eyes of 32 subjects with NTG, there were 30 right eyes and 28 left eyes. The success rate of SLT was 61.7%. Using 3 types of anti-glaucoma medications (coefficient=-2.2, OR=0.1, P=0.02) and a thicker retinal nerve fiber layer thickness (coefficient=-0.04, OR=0.96, P=0.04) were associated with failure (univariate analysis). In multivariate analysis, a higher pre-SLT IOP (coefficient=1.1, OR=3.1, P=0.05) and a lower 1-week IOP (coefficient=-0.8, OR=0.5, P=0.04) were associated with success. SLT was successful in over 60% of treated NTG patients. A higher pre-SLT IOP and a greater IOP reduction at 1-week post-SLT were predictors of a successful outcome.

Intraocular pressure-lowering medications and long-term outcomes of selective laser trabeculoplasty

BACKGROUND

To investigate the effects of current intraocular pressure-lowering medications on the efficacy of selective laser trabeculoplasty.

DESIGN

Retrospective chart review of records from an urban glaucoma clinic in Sydney, Australia.

PARTICIPANTS

Patients who received their first selective laser trabeculoplasty between 2002 and 2005 were studied (grouped from 0 to 3 according to the number of pre-selective laser trabeculoplasty medications, and followed for 5 years). Those with previous argon laser therapy, trabeculectomy or angle-closure were excluded.

METHODS

Selective laser trabeculoplasty (Ellex) used to deliver 180 or 360 degree of treatment, under the same protocol.

MAIN OUTCOME MEASURES

Responders were defined by ≥20% reduction from baseline intraocular pressure. Data were censored when pressure-lowering intervention was required. The mean intraocular pressure, survivor, response rate, number and type of medications were compared.

RESULTS

There were 206 patients with ocular hypertension, primary, pseudo-exfoliation, or pigmentary glaucoma who used none (n = 20), one (n = 33), two (n = 61) or three or more (n = 92) pre-selective laser trabeculoplasty topical anti-glaucoma medications. The mean baseline intraocular pressures for each group was 23.7, 22.2, 20.7 and 20.4 mmHg, respectively (P = 0.061). Post-treatment mean intraocular pressure was 17.9, 17.7, 15.5, and 15.7 mmHg; percentage reduction was similar between groups (23.6-25.6%, P = 0.20). Kaplan-Meier survival analysis showed comparable survival rates across groups (P = 0.445). At 60 months, 11.1, 17.1, 30.5 and 11.5% of responders remained in each group. Higher proportions of patients in groups 2 and 3 required further laser or surgery.

CONCLUSION

The number of pre-selective laser trabeculoplasty medications did not affect the intraocular pressure-lowering effectiveness of selective laser trabeculoplasty; however, groups on more medications required more pressure-lowering interventions.