The Effectiveness and Safety of Micropulse Cyclophotocoagulation in the Treatment of Ocular Hypertension and Glaucoma

Outcomes of Micropulse Transscleral Cyclophotocoagulation in Uveitic Glaucoma

PURPOSE

To report a case series of patients with uveitic glaucoma who were treated with micropulse transscleral cyclophotocoagulation (mpCPC).

METHODS

This retrospective case series consists of patients from the University of Colorado Sue Anschutz-Rodgers Eye Center from 2015 to 2020 who were diagnosed with uveitic glaucoma. Information collected includes demographic data, type of uveitis, glaucoma severity, and prior glaucoma surgeries. Pre- and postoperative best corrected visual acuity, intraocular pressure (IOP), glaucoma medications, degree of inflammation, and uveitis therapies were included up to 36 months postoperatively. Surgical success was defined as an IOP reduction of 30% with achievement of IOP goal using the same number of glaucoma medications or less at 6 months or 1 year. Uveitis success was defined as the absence of persistent anterior uveitis at 3 months.

RESULTS

Six patients and seven eyes with uveitic glaucoma underwent mpCPC. Types of uveitis included idiopathic anterior uveitis, HLA-B27-associated anterior uveitis, varicella zoster virus anterior uveitis, juvenile idiopathic arthritis-associated chronic anterior uveitis, lichen planus-associated intermediate uveitis, and sarcoidosis-associated panuveitis. Two of six eyes (33.3%) at 6 months and three of five eyes (60%) at 1 year achieved surgical success. Around 6 months postoperatively, two out of seven eyes (28.6%) required Ahmed glaucoma valve placement (n = 1) or repeat mpCPC (n = 1). One eye (14.3%) required phacoemulsification with goniotomy followed by an Ahmed glaucoma valve 18 months after mpCPC. There were no cases of persistent anterior uveitis, hypotony, or phthisis after mpCPC in this cohort.

CONCLUSIONS

Micropulse transscleral cyclophotocoagulation may safely reduce intraocular pressure in some patients with uveitic glaucoma without exacerbation of intraocular inflammation. Multiple treatments may be required to achieve longer-term success.

Micropulse Transscleral Cyclophotocoagulation in Non-Incisional Eyes with Ocular Hypertension and Primary Open-Angle Glaucoma

Purpose

To investigate the safety and effectiveness of micropulse transscleral cyclophotocoagulation (MPTSCPC) in non-incisional eyes with ocular hypertension (OHT) and early, moderate, and severe primary open-angle glaucoma (POAG).

Methods

Retrospective cohort study of eyes that underwent MPTSCPC from 2016 to 2019 at an outpatient clinic in Canada. Eyes were excluded if any incisional procedures, except cataract surgery, were performed prior to MPTSCPC treatment. Laser power ranged from 900 to 2500mW.

Results

A total of 153 eyes from 93 patients were included (OHT n=22; early POAG n=46; moderate POAG n=35; severe POAG n=50). The baseline IOP was 18.37 ± 4.76mmHg in the total cohort. All cohorts experienced a significant mean IOP reduction by final follow-up (total p<0.001; OHT p=0.003; early POAG p<0.001; moderate POAG p=0.022; severe POAG p=0.015). Overall, 52.9% of eyes achieved an IOP reduction of ≥20% from baseline to final follow-up (OHT 59.1%; early POAG 58.7%; moderate POAG 45.7%; severe POAG 50.0%). There was worsening in best-corrected visual acuity in the total cohort (mean difference=0.11 ± 0.36 logMAR, p=0.11), mostly attributable to cataract progression (34.1% of phakic eyes) and ocular surface disease (7.2%). The number of topical medications and drug classes remained unchanged in the total cohort (p=0.425 and p=0.791, respectively). Twenty-two eyes (14.4%) required retreatment, which provided an additional IOP reduction of 1.26mmHg (p=0.344). By final follow-up, 8 eyes (5.2%) required escalation to incisional procedures.

Conclusion

MPTSCPC is a safe and effective adjunct IOP-lowering treatment in non-incisional eyes with OHT and POAG.

Micropulse transscleral cyclophotocoagulation in canine glaucoma: A retrospective study evaluating sweep velocity

OBJECTIVE

To report preliminary results of MP-TSCP in canine patients with glaucoma while evaluating sweep velocity, treatment efficacy, and safety utilizing standardized surgical parameters.

ANIMAL STUDIED

Client-owned dogs that underwent MP-TSCP at a veterinary referral hospital.

PROCEDURE

Medical records of 19 eyes (14 dogs) treated with MP-TSCP were reviewed. Eleven eyes were treated with a 10 s/sweep (s) velocity and 8 eyes with a 20 s/s. Laser duty cycle was set at 31.3%, mean laser energy was 2766 mW, and mean duration was 120 s per hemisphere. Minimum post-operative follow-up was 6 months. Outcomes of intraocular pressure (IOP), vision status, degree of antiglaucoma medications, and complications were evaluated.

RESULTS

There was a significantly lower median (IQR) IOP (<25 mmHg) at each timepoint postoperatively compared to IOP pre-operatively (p < 0.05). The overall success rate for IOP control at 6 months was 84%, 100% for the 10 s/s and 62.5% for the 20 s/s. Vision was preserved in 10/11 (90%) eyes from the 10 s/s group and 4/8 (50%) eyes from the 20 s/s group at 6 months. Average number of glaucoma medications in the 10 s/s group decreased from 4.4 to 1.5 and from 3.3 to 2.5 in the 20 s/s group. Post-operative complications were mild and resolved within 1 week.

CONCLUSIONS

MP-TSCP is a non-invasive treatment alternative for canine glaucoma. Employing higher energy levels rendered long-term IOP control while retaining a high safety profile with minimal postoperative complications. There was no statistical difference between a 10 s/s and 20 s/s surgical velocity, both leading to successful surgical outcomes up to 6 months post-operatively.

Efficacy of Micropulse Laser Cyclophotocoagulation Therapy in Primary Angle Closure Glaucoma

PRCIS

In primary angle closure glaucoma (PACG), micropulse cyclophotocoagulation resulted in a significant reduction in intraocular pressure (IOP), and the number of antiglaucoma medications without any sight-threatening complications. However, the IOP lowering efficacy decreased over time.

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of micropulse trans-scleral cyclophotocoagulation (MP-TSCPC) in PACG.

PATIENTS AND METHODS

Thirty-three phakic PACG eyes with patent laser peripheral iridotomy and IOP uncontrolled on maximum tolerable antiglaucoma medications (AGMs), scheduled for trabeculectomy, were given a trial of MP-TSCPC (810 nm laser, 2000 mw power for 180 seconds, 360 degrees). The primary outcome measure was a success at 1 year with IOP ≤18 mm Hg and ≤15 mm Hg with (qualified success) or without (absolute success) AGMs after a single session of MP laser. Secondary outcome measures were changes in pupillary diameter, visual acuity, central macular thickness, and subjective pain perception.

RESULTS

Thirty-two out of 33 PACG patients completed 12 months of follow-up. The mean age of patients was 54.7±8.9 years; male:female ratio was 1:1. The baseline IOP was 25.7±5.3 mm Hg, which reduced to 17.9±4.6 mm Hg at the end of 12 months (P<0.0001). Twenty eyes (62.5%) achieved qualified success, and 1 eye (3.125%) had absolute success at 12 months for IOP ≤18 mm Hg; 6 eyes (18.75%) had qualified success, and 1 eye (3.125%) had absolute success for IOP ≤15 mm Hg at 12 months follow-up. A significant reduction was also observed in the number of AGMs (4.4±0.8 at baseline to 2.9±1.1 at 12 months; P <0.0001). Five eyes (15.6%) received additional treatment-3 eyes (9.4%) requiring a subsequent filtering procedure, and 2 eyes (6.2%) requiring an additional MP-TSCPC session. No significant change in pupillary diameter (P=0.489) or central macular thickness (P=0.938) was noted at 12 months. There was a transient drop of visual acuity >2 lines in 1 patient due to cystoid macular edema, and no major postlaser complications were noted.

CONCLUSIONS

MP-TSCPC can be used as an interim procedure to reduce IOP in PACG eyes and delay the need for invasive surgery. Most patients require continued use of glaucoma medications, and target IOPs achieved are in the high teens.

The efficacy and safety of micropulse transscleral laser treatment in glaucoma: a systematic review and meta-analysis

OBJECTIVE

Micropulse transscleral laser treatment (mTLT) is the latest alternative intraocular pressure (IOP) lowering approach for glaucoma patients. This meta-analysis aims to evaluate the efficacy and safety of mTLT and continuous wave transscleral cyclophotocoagulation (CW-TSCPC) for the treatment of glaucoma.

METHODS

We searched the PubMed, Embase, and Cochrane Library of Systematic Reviews databases from January 2000 to July 2022 to identify studies that, evaluated the efficacy and safety of mTLT in glaucoma. There were no restrictions regarding study type, patient age, or type of glaucoma. We analysed the reduction in IOP and the number of anti-glaucoma medications (NOAM), retreatment rates, and complications between mTLT and CW-TSCPC treatment. Publication bias was conducted for evaluating bias. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA 2020) reporting guideline.

RESULTS

We identified 6 eligible studies of which only 2 RCTs and 386 participants with various types of glaucoma at different stages were ultimately included. The results revealed significant IOP decreases after mTLT up to 12 months and significant NOAM reductions at 1 month (WMD=-0.30, 95% CI -0.54 to 0.06), and 3 months (WMD=-0.39, 95% CI -0.64 to 0.14) in mTLT compared to CW-TSCPC. Moreover, the retreatment rates (Log OR=-1.00, 95% CI -1.71 to -0.28), hypotony (Log OR=-1.21, 95% CI -2.26 to -0.16), prolonged inflammation or uveitis (Log OR=-1.63, 95% CI -2.85 to -0.41), and worsening of visual acuity (Log OR=-1.13, 95% CI -2.19 to 0.06) occurred less frequently after mTLT.

CONCLUSION

Our results demonstrated that mTLT could lower the IOP until 12 months after treatment. mTLT seems to have a lower risk of retreatment after the first procedure, and mTLT is superior to CW-TSCPC with respect to safety. Studies with longer follow-up durations and larger sample sizes are necessary in the future.

TRIAL REGISTRATION NUMBER

INPLASY202290120.

Micropulse Transscleral Cyclophotocoagulation Results in Secondary Glaucoma

The aim of this study was to analyze the long-term outcome of first session of micropulse transscleral cyclophotocoagulation (MP-CPC) for refractory glaucoma developed after vitreoretinal surgery combined with silicone oil implantation. The inclusion criteria of this consecutive case series were: patients with secondary glaucoma in the refractory stage who underwent MP-CPC between 2018 and 2021, vitreoretinal surgery combined with silicon oil implantation, and at least a 24-month follow-up period after MP-CPC. Success was defined as the baseline eye pressure reduced at least 20%, and it should be ranged between 10 to 20 mmHg without further MP-CPC at the end of the follow-up. For this retrospective study, 11 eyes of 11 patients were selected. The reduction in IOP was found to be significant (p = 0.004) at the end of the follow-up time, and the success rate was 72% according to our results. The change in the number of antiglaucoma agents in the administered eyedrops was not significant compared to the baseline values. At the end of the follow-up period the change in BCVA values was not significant (p = 0.655). Our results confirm significant IOP lowering effect of this subthreshold method preserving visual performance safely even in eyes with previous vitrectomy surgery with a silicone oil implantation.

MicroPulse Transscleral Laser Therapy Dosimetry Utilizing the Revised P3 Delivery Device: A Randomized Controlled Trial

PURPOSE

To compare the long-term effectiveness and safety outcomes of 2 treatment dosages of the MicroPulse Transscleral Laser Therapy (MPTLT) procedure on intraocular pressure (IOP) control in patients with primary open-angle glaucoma.

DESIGN

Single-blinded randomized controlled trial.

SUBJECTS

A total of 19 patients with POAG without prior history of incisional glaucoma surgery.

METHODS

Subjects randomized into 2 treatment groups, 100-second (total energy 78.25 joules [J], fluence 109.2 J/cm²) or 120-second (total energy 93.9 J, fluence 131.0 J/cm²) total treatment duration, underwent the MPTLT procedure with the revised P3 delivery probe delivering 2.5 W energy, 31.3% duty cycle, applied in 3 sweeps per hemisphere, avoiding 3 and 9 o'clock. All subjects were followed at 1, 3, 6, 9, and 12 months to compare reduction in IOP and medication.

MAIN OUTCOME MEASURES

Absolute and percentage IOP reduction at 6 months.

RESULTS

The treatment groups were similar in age, sex, and stage of glaucoma at baseline (all P > 0.05). The 120-second group had significantly better baseline best-corrected visual acuity (BCVA) and a higher percentage of patients with prior MPTLT therapy (ranging from 4-19 months before study). Significantly greater IOP reduction was noted in the 120-second group compared with the 100-second group at 3 months, with mean IOP reduction of 7.3 ± 4.2 mmHg (vs. 0.9 ± 2.5 mmHg, P = 0.006) and percentage IOP reduction of 32.2% ± 18.3% (vs. 4.1% ± 13.7%, P = 0.007). The 120-second group continued to outperform at 6-month follow-up: mean IOP reduction of 9.0 ± 4.8 mmHg (vs. 0.8 ± 2.5 mmHg, P = 0.016) and percentage IOP reduction of 37.8% ± 19.8% (vs. 3.6% ± 13.3%, P = 0.021). At 12 months, 37.5% and 18.2% of the 100- and 120-second groups, respectively, required an additional IOP-lowering procedure (P = 0.35); however, Kaplan-Meier analysis of time to intervention was not significantly different (P = 0.38). There were no vision-threatening complications or changes in BCVA during the study period.

CONCLUSIONS

This study demonstrates a dose-response relationship with improved IOP control and excellent safety profile in patients treated with higher treatment total energy and fluence using the revised MPTLT probe.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Evidence-Based Consensus Guidelines Series for MicroPulse Transscleral Laser Therapy - Surgical Technique, Post-Operative Care, Expected Outcomes and Retreatment/Enhancements

Purpose

To provide expert consensus and evidence-based current guidelines on treatment technique, postoperative care, expected outcomes and retreatment for MicroPulse Transscleral Laser Treatment (TLT).

Methods

A comprehensive search of PubMed led to the identification and analysis of 61 studies on MicroPulse TLT. To provide guidance in areas where there was not enough available literature, a three-round Delphi method was conducted involving 10 international experts in MicroPulse TLT.

Results

The response rate was 70% in the first round, 70% in the second round, and 80% in the third round of the Delphi method. Once all responses were aggregated, a live meeting was held with 90% attendance, and consensus was achieved on each of the findings detailed in this manuscript.

Conclusion

Used within appropriate treatment parameters, with proper technique and patient selection, MicroPulse TLT is a safe and effective treatment for many types and severities of glaucoma. MicroPulse TLT represents a useful addition to the glaucoma armamentarium.

[Glaucoma treatment by transscleral cyclophotocoagulation in micropulse technology in a low-income setting]

BACKGROUND

Glaucoma is the leading cause of irreversible blindness worldwide. The prevalence of glaucoma is particularly high in rural regions of Tanzania. Poverty and an inadequate ophthalmic infrastructure increase the difficulty of glaucoma treatment.

OBJECTIVE

Due to the limited access to eye drops or surgical therapy, the effectiveness of transscleral cyclophotocoagulation in micropulse technology (CPC-M) in advanced glaucoma was investigated in the present study.

MATERIALS AND METHODS

We included n = 50 eyes of 35 adult patients with advanced glaucoma and a glaucoma-typical papillary excavation with cupdisc ratio (CDR) ≥ 0.9, regardless of the glaucoma entity. The mean intraocular pressure (IOP) prior to treatment was 34 mm Hg (± 14 mm Hg). The operation was performed under retrobulbar anesthesia with the A.R.C. FOX 810 diode laser (A.R.C. Laser, Nuremberg, Germany; mean energy 127 J ± 10 J).

RESULTS

An IOP between 6 and 21 mm Hg or an IOP reduction by at least 20% of the initial value was defined as success. The success criteria were met by 71% of reevaluated eyes (n = 21) 3 months after treatment, and mean IOP was 19 mm Hg (± 13 mm Hg). Mean IOP 9 months postoperatively (n = 20) was 18 mm Hg (± 10 mm Hg) and the success criteria were met in 65% of cases. Seven eyes did not meet the success criteria: six eyes had a further increase in IOP and one eye showed intraocular hypotension.

CONCLUSION

The CPC‑M represents a good, inexpensive, and easily accessible treatment option for advanced glaucoma in order to reduce the likelihood of blindness in a low-income setting.

Surgical Outcome of Combined MicroPulse Transscleral Laser Therapy with Phaco Emulsification in Patients with Cataract and Glaucoma

Purpose:

To determine the effectiveness and safety of combined MicroPulse transscleral laser therapy (TLT) and phacoemulsification in patients with co-existing cataracts and glaucoma.

Methods:

A retrospective consecutive case series of 22 eyes of 19 patients with co-existing cataract and glaucoma. The patients underwent MicroPulse TLT, phacoemulsification, and intraocular lens implantation during the same setting. A comparison of baseline data with the data at 18 months follow-up was made to determine the variation in best-corrected visual acuity (BCVA), intraocular pressure (IOP), and changes in the number of anti-glaucoma drugs.

Results:

Twenty-two eyes of 19 patients (57.9% were female) underwent combined MicroPulse TLT and phacoemulsification. The mean age was 60.5±9.3 years (range: 39.0 to 76.0). Nine eyes (40.9%) had primary open-angle glaucoma, nine eyes (40.9%) had chronic angle-closure glaucoma, and four eyes (18.2%) had pseudoexfoliation glaucoma. The mean baseline IOP was 26.3±4.7, which was significantly reduced to 15.3±2.4 mmHg (43.9%±10.2%) at 18 months (p<0.001). The median number of glaucoma medications was 4 (2 to 5) at baseline and 2 (0 to 4) at 18 months (p=0.002). The mean BCVA was 0.84±0.31 LogMAR (Snellen: 20/138) at baseline and 0.28±0.23 LogMAR (Snellen:20/38) at 18 months (p<0.001). The mean follow-up period was 15.8±3.0 months (range 12 to 18).

Conclusions:

Combined MicroPulse TLT and phacoemulsification was a safe and effective procedure that achieved reduction in both IOP and glaucoma medications for up to 18 months, with no associated vision-threatening complications.

Short-term outcomes of micropulse transscleral laser therapy using the revised delivery probe in refractory glaucoma

PURPOSE

To evaluate the effectiveness of MicroPulse^® transscleral laser therapy (MP-TLT) using both the original and revised MicroPulse P3^® delivery probes in patients with refractory glaucoma.

STUDY DESIGN

Retrospective study METHODS: We analyzed the data of patients with refractory glaucoma who underwent MP-TLT with the original and with the revised MicroPulse P3^® Delivery Device from January 2018 to December 2020 at the University of Tokyo Hospital and who were followed up for 3 months. Patients' demographics, preoperative and postoperative intraocular pressure (IOP), medication scores, best-corrected visual acuity (BCVA), and complications were analyzed.

RESULTS

This study enrolled 40 patients in both probe groups. At baseline, the mean IOP was 31.1 mmHg in the original group and 29.2 mmHg in the revised group, and it decreased to 22.6 mmHg and 21.6 mmHg after 3 months, respectively (paired t-test p=0.001, 0.001). No significant difference was noted between the number of medications and BCVA at baseline and 3 months in either probe group (paired t-test, p>0.05). Nor were any serious complications observed.

CONCLUSION

MP-TLT using the revised MicroPulse P3^® Delivery Device for the treatment of refractory glaucoma was effective in reducing IOP across glaucoma types with an excellent safety profile and was well-tolerated by the patients.

Netarsudil as a Predictor of Response for MicroPulse Transscleral Laser Therapy: A Pilot Study

PURPOSE

To investigate the role of netarsudil as an outcome predictor of MicroPulse transscleral laser therapy (MPTLT).

DESIGN

Retrospective comparative study.

SUBJECTS

Forty-seven eyes in 33 adult patients with glaucoma with a minimum of 1 month of follow-up after netarsudil treatment and 3 months of follow-up after MPTLT were included. Eyes receiving intraocular pressure (IOP)-lowering procedures in the interim were excluded.

INTERVENTION

Ophthalmic eyedrops of netarsudil at 0.02%, followed by MPTLT treatment.

MAIN OUTCOME MEASURES

Correlation of success between netarsudil and MPTLT. Netarsudil success was defined as an IOP reduction ≥ 20% from baseline, whereas MPTLT success was defined as an IOP reduction ≥ 20% without additional IOP-lowering medications. Secondary outcomes included success rates, mean IOP reduction, adverse effects after each treatment, and netarsudil discontinuation rate.

RESULTS

We found a positive correlation between the netarsudil response and the subsequent MPTLT response (odds ratio, 3.73; 95% confidence interval, 1.05-13.24; P = 0.041). Among netarsudil responders, 73.7% (14/19) of eyes subsequently responded to MPTLT, whereas among netarsudil nonresponders, 42.8% (12/28) of eyes subsequently responded to MPTLT (P = 0.037). From netarsudil, 44.4% of eyes were successful; from MPTLT, 55.3% of eyes were successful. The mean IOP reductions were 2.83 ± 5.74 mmHg from netarsudil and 3.15 ± 6.43 mmHg from MPTLT. Overall, the rate of netarsudil discontinuation was 55.3%. The most common reasons for netarsudil discontinuation were adverse effects (48.9%), followed by high cost (19.1%). The most common adverse effects to netarsudil were conjunctival hyperemia (48.9%) and blurred vision (8.5%). There were no adverse events reported after MPTLT. After MPTLT, 29.8% of eyes required additional IOP-lowering procedures.

CONCLUSIONS

The netarsudil response may serve as a predictive marker of the MPTLT response, with over 70% of netarsudil responders subsequently responding favorably to MPTLT in this study.

Ciliochoroidal effusion and its association with the outcomes of micropulse transscleral laser therapy in glaucoma patients: a pilot study

We investigate the development of ciliochoroidal effusion following micropulse transscleral laser therapy (MPTLT) and evaluate the relationship between the early postoperative ciliochoroidal effusion (ECE) and short-term treatment outcomes. Glaucoma patients who underwent MPTLT were assessed for ciliochoroidal effusion by anterior segment optical coherence tomography (AS-OCT) at postoperative 1, 4, 12 weeks. The subjects were classified based on AS-OCT findings at postoperative 1 week into eyes with and without ECE. The absolute intraocular pressure (IOP), IOP reduction and number of antiglaucoma medications were compared between eyes with and without ECE. A total of 50 eyes were included, of which 23 (46%) developed ciliochoroidal effusion at postoperative 1 week. Almost all effusion resolved at 4 weeks. At 12 weeks, the mean IOP (SD) significantly decreased from 28.5 (12.8) mmHg to 17.8 (10.5) mmHg (p < 0.001), and the mean number of medications (SD) decreased from 4.1 (0.9) to 3.3 (1.1) (p < 0.001). Eyes with ECE had significantly greater IOP reduction (p = 0.009) and lower absolute IOP (p = 0.008) at the 4-week visit. There was no significant difference in number of medications between the groups. In conclusion, ciliochoroidal effusion was commonly observed following MPTLT. Eyes with ECE had overall greater IOP reduction during early post-operation.

Topical Anesthesia Offers Sufficient Pain Control for MicroPulse Transscleral Laser Therapy for Glaucoma

Introduction

The aim of this study was to evaluate patient pain during and after MicroPulse Transscleral Laser Therapy (TLT) and vision-related quality of life using two different anesthesia protocols: “Topical Plus” anesthesia without standby anesthesia (study group), and analgosedation with standby anesthesia (control group).

Methods

A retrospective, comparative chart review was conducted to evaluate patient pain between the two groups based on an analog pain scale at baseline and postoperatively (1 hour, 6 hours, 1 day, 1 week, and 1 month). Furthermore, vision-related quality of life at baseline was compared at 1 month postoperatively.

Results

Four eyes underwent MicroPulse TLT under Topical Plus anesthesia and 4 eyes underwent analgosedation. The mean age at the time of the MicroPulse TLT was 78.3 ± 6.4 years. In the study group, the reported pain level increased significantly immediately after the treatment (from 0.5 to 2.8, p=0.003; mild pain); however, no difference was found at any later time point compared to baseline. The vision-related quality of life was similar in both groups and was not negatively impacted by the MicroPulse TLT at 1 month after the treatment. Discussion/Conclusion. The Topical Plus anesthesia protocol provides adequate pain control for the patient to remain comfortable during and post-MicroPulse TLT treatment, with no changes in vision-related quality of life. Although the sample size was small and, thus, the results cannot be generalized, this case series showed that it is possible to perform MicroPulse TLT under topical anesthesia.

Medium-term Outcomes of Micropulse Transscleral Cyclophotocoagulation in Refractory Glaucoma

Aim

To describe our first experience with the efficacy of micropulse transscleral cyclophotocoagulation (MP-TSCPC) procedure in the treatment of different glaucoma subtypes refractory to topical medication using a standard protocol.

Materials and methods

Retrospective, interventional study in a series of 35 eyes of 34 patients with refractory glaucoma who underwent MP-TSCPC. Treatment success was defined as an intraocular pressure (IOP) reduction of at least 20% compared to baseline with or without IOP-lowering medication or eventual retreatment.

Results

Mean age was 78.0 years. The glaucoma subtypes included pseudoexfoliative (PSXG) (16), neovascular (NVG) (9), primary open-angle (POAG) (7), congenital (1), aphakic (1), and secondary glaucoma (1). The mean preoperative IOP was 31.8 ± 10.5 mm Hg and at month 12 was 21.9 ± 10.6 mm Hg (p < 0.05). The average baseline number of glaucoma medications pretreatment was 3.0 ± 1.0 and at month 12 was 2.3 ± 1.2 (p = 0.114). At month 12, success was achieved in 15 eyes (42.9%) with an IOP-lowering effect of 31.1%. PSXG was correlated with IOP reduction (p = 0.037) and had a higher likelihood of success (p = 0.031). As complications, there was one case of prolonged hypotony and another case of developed postoperative neurotrophic keratopathy.

Conclusion

Using our standardized protocol, MP-TSCPC seems a safe and relatively effective treatment in the medium-term for refractory glaucoma, achieving good results in PSXG.

Clinical significance

There are few studies published about MP-TSCPC. The results of our study contribute to expanding on the short evidence reported at present, emphasizing our considerable percentage of PSGX.

How to cite this article

Valle IT, Bazarra SP, Taboas MF, et al. Medium-term Outcomes of Micropulse Transscleral Cyclophotocoagulation in Refractory Glaucoma. J Curr Glaucoma Pract 2022;16(2):91-95.

Normal-tension glaucoma: Current concepts and approaches-A review

Normal tension glaucoma (NTG) has remained a challenging disease. We review, from an epidemiological perspective, why we should redefine normality, act earlier at lower pre-treatment intraocular pressure (IOP) level, and the role of ocular perfusion pressures, noting that perfusion is affected by defective vascular bed autoregulation and endothelial dysfunction. The correlation of silent cerebral infarcts (SCI) and NTG may indicate that NTG belongs to a wider spectrum of small vessel diseases (SVD), with its main pathology being also on vascular endothelium. Epidemiological studies also suggested that vascular geometry, such as fractal dimension, may affect perfusion efficiency, occurrence of SCI, SVD and glaucoma. Artificial intelligence with deep learning, may help predicting NTG progression from vascular geometry. Finally, we review latest evidence on the role of minimally-invasive glaucoma surgery, lasers, and newer drugs. We conclude that IOP is not the only modifiable risk factors as, many vascular risk factors are readily modifiable.

MicroPulse Transscleral Laser Therapy Demonstrates Similar Efficacy with a Superior and More Favorable Safety Profile Compared to Continuous-Wave Transscleral Cyclophotocoagulation

Purpose. The aim of this study was to compare effectiveness and safety of MicroPulse transscleral laser therapy (MP-TLT) using the original MicroPulse P3® device and continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) using the G-Probe® device in glaucoma. Methods. Spherical equivalent, intraocular pressure (IOP), best-corrected visual acuity (BCVA), and number of topical or oral ophthalmic pressure-reducing medications were registered at every time point, up to the last follow-up at 12 months. A complete slit-lamp examination was conducted to record the following complications: corneal edema, persistent ocular hypotony (IOP ≤5 mmHg) on two consecutive follow-up visits, choroidal detachment, phthisis bulbi, sympathetic ophthalmia, cystoid macular edema, or other abnormal ocular findings. Success was defined as IOP between 6 and 21 mmHg and >20% reduction in IOP with or without antiglaucoma medications. Results. 47 eyes underwent MP-TLT and 150 CW-TSCPC. At 12 months, success was achieved in 88.6% in the CW-TSCPC group and 87.5% in the MP-TLT group ( $p$  = 0.883). In the CW-TSCPC group, eyes achieved a 42.4% IOP reduction (from 28.3 ± 12.3 mmHg to 15.3 ± 6.0 mmHg) and a 31.1% reduction (from 22.0 ± 7.2 mmHg to 15.7 ± 4.8 mmHg) in the MP-TLT group. Visual acuity remained primarily unaltered in both groups. Conclusion. MP-TLT was as effective in lowering IOP as CW-TSCPC and achieved comparable success. Additionally, MP-TLT demonstrated consistent and effective outcomes at every time point. The improved safety profile of MP-TLT allows the therapeutic spectrum to be broadened, granting ophthalmologists’ treatment of glaucoma in earlier stages of glaucoma than those typically treated with CW-TSCPC, i.e., early to moderate and to patients with good central-vision.

MicroPulse® transscleral laser therapy in the management of glaucoma patients

PURPOSE

To evaluate the efficacy and safety of MicroPulse® transscleral laser therapy (TLT) in the management of glaucoma patients.

METHODS

A prospective, interventional, non-comparative case series was conducted in the department of ophthalmology, Ain Shams University Hospital on 61 eyes of 46 patients with various glaucoma types and of severity, ranging from mild to severe. In addition to best-corrected visual acuity (BCVA), intraocular pressure (IOP) and the number of glaucoma medications were recorded before and after treatment, along with the postoperative need for systemic carbonic anhydrase inhibitors (CAI), success rates, number of treatment sessions and postoperative complications. Success was defined as an IOP of 6-18 mmHg or at least a 30% decrease from preoperative IOP in the absence of any vision-threatening complications during the 6-month follow-up period.

RESULTS

MicroPulse TLT was performed on 61 glaucomatous eyes. Eleven of the 61 eyes (18%) that did not achieve IOP between 6-18 mmHg, or at least a 30% decrease from baseline at 6 months, had a repeat MicroPulse TLT session. At 6 months follow-up post a single MicroPulse TLT session, the mean IOP reduction was 35.9 ± 14.2%; and 6 months after the second session, it was 36.2 ± 17.5% (p < 0.001). The success rate after the first session was 73.8% which increased to 78.7% after the second session. The mean anterior chamber (AC) cell reaction was +1.9 ± 0.8 at 1 day, +1.0 ± 0.7 at 1 week, and +0.2 ± 0.4 at 1 month postoperatively. No cells were detected in any of the cases at 3 and 6 months follow-up (p < 0.001). The average number of anti-glaucoma eye drops before MicroPulse TLT was 2.6 ± 1.0. Postintervention, the average number of anti-glaucoma eye drops was 1.7 ± 1.2, and sustained at 6 months follow-up after the last treatment session (p < 0.001). There were no significant complications were noted. One eye developed transient hypotony for 3 months after MicroPulse TLT.

CONCLUSIONS

MicroPulse TLT is safe and effective in lowering IOP in a variety of glaucoma types and severity.

Outcomes of a combination of augmented MicroPulse and limited Continuous Wave Cyclophotocoagulation in patients with refractory glaucoma

Purpose

To assess the safety and effectiveness of augmented MicroPulse (MP-TSCPC) with limited Continuous Wave Transscleral Cyclophotocoagulation (CW-TSCPC) in patients with refractory glaucoma.

Methods

Thirty-eight eyes of 38 patients underwent combined MP-TSCPC and CW-TSCPC at Massachusetts Eye and Ear. Kaplan–Meier survival curves and Wilcoxon paired sign rank tests were performed to evaluate intraocular pressure (IOP), glaucoma medication burden, best corrected visual acuity (BCVA), and adverse events.

Results

With success defined as IOP reduction ≥ 30% and IOP between 5 and 18 mmHg, the cumulative probability of success at 1 year and 1.5 years were 0.81 (95% confidence interval (CI), 0.68–0.96) and 0.65 (95% CI, 0.50–0.86), respectively. With success defined as IOP reduction ≥ 50% and IOP between 5 and 18 mmHg, the success probability at 1 year and 1.5 years were 0.72 (95% CI, 0.57–0.89) and 0.56 (95% CI, 0.40–0.78), respectively. IOP and medication burden reductions were significant at all follow-up visits compared to baseline. Average IOP decreased from 27.9 mmHg at baseline to 11.4 mmHg at 1 year (p < 0.001) and 10.0 mmHg at 1.5 years (p < 0.001). Average medication burden decreased from 3.8 to 1.7 at 1.5 years (p = 0.001). No significant differences in visual acuity were observed at any time point. No long-term sight-threatening complications due to the combined procedure were observed, and most of the complications observed were mild and transient.

Conclusion

In patients with refractory glaucoma, the combination of augmented MP-TSCPC with limited CW-TSCPC provides a significant IOP-lowering effect and decrease in medication burden without increased risk of postoperative complications.

An update on continuous-wave cyclophotocoagulation (CW-CPC) and micropulse transscleral laser treatment (MP-TLT) for adult and paediatric refractory glaucoma

PURPOSE

Continuous-wave cyclophotocoagulation (CW-CPC) is often preferred to medical and surgical treatments for managing refractory glaucoma. This review summarizes diode CW-CPC indications, history, histopathology, methods, efficacy and safety. It also provides an overview of the latest data available on micropulse transscleral laser treatment (MP-TLT) that uses repetitive micropulses of diode laser energy in an off-and-on cyclical fashion.

METHODS

A literature review was conducted on transscleral CW-CPC (CW-TSCPC), endoscopic CPC (ECP) and MP-TLT. Relevant series of adult and paediatric patients were included for assessing the procedures.

RESULTS

Regarding CW-TCPC, highly variable success rates are reported in the literature, depending on the definition of success, type of underlying glaucoma, energy settings, follow-up duration and retreatment rates. CW-CPC often needs to be repeated, especially in paediatric patients. CW-CPC exposes to risks of inflammation and chronic ocular hypotony or phthisis with irreversible visual loss. CW-TSCPC has mainly been used in very severe forms of glaucoma, in painful eyes with limited visual potential or after filtering surgery failure. Published data on ECP are more limited but overall good success rates have been reported. Through the direct visualization of the targeted ciliary body in anatomically abnormal eyes, ECP is the preferred surgical procedure in paediatric refractory glaucoma. Complication rates are relatively low after ECP; however, large studies with long-term follow-up are needed. ECP may be used in difficult, refractory cases, but it is often used earlier when combined with cataract surgery. Despite limited data on the exact mechanism of action of MP-TLT and a lack of standardization of laser settings, the first data from heterogeneous case series shows that it has a similar efficacy and a better safety profile compared to CW-TSCPC in the medium term.

CONCLUSION

Although they may lead to sight-threatening complications, both CW-TSCPC and ECP seem effective. ECP appears to be superior to CW-TSCPC in paediatric refractory glaucoma. Unlike ECP combined with cataract surgery, evidence supporting a wider use of CW-TSCPC and MP-TLT in earlier stages of neuropathy is lacking. While it now appears that the safety profile of MP-TLT is superior to that of CW-CPC, robust prospective comparative studies including homogeneous and well-defined cohorts of patients are still needed to confirm an at least comparable efficacy in the long term.

MicroPulse® Transscleral Laser Therapy - Fluence May Explain Variability in Clinical Outcomes: A Literature Review and Analysis

Since the first peer-reviewed publication on MicroPulse^® Transscleral Laser Therapy (MP-TLT) in 2010, authors worldwide have used a wide range of treatment parameter combinations with varying clinical efficacy in terms of the magnitude of intraocular pressure reduction, success rate, durability, and safety profile. This has made it difficult to determine the proper parameters necessary to optimize efficacy and safety, and has made comparison of results from one investigation to another difficult. The first goal of this paper is to explain and highlight the impact of the choices of exposure time and the number of sweeps per hemisphere in terms of “sweep velocity” on energy delivery to the eye. These treatment parameters are underreported in the literature. The second goal is to introduce fluence as a “dose” metric, that combines all the treatment parameters and constants into a single number. Fluence may be a better light-dose metric and a more reliable indicator of clinical outcomes compared to total energy.

Micropulse laser trabeculoplasty under maximal tolerable glaucoma eyedrops: treatment effectiveness and impact of surgical expertise

AIM

To evaluate the effectiveness of micropulse laser trabeculoplasty (MLT) for eyes with open angle glaucoma (OAG) under maximal tolerable glaucoma eyedrops and to assess the effect of expertise performing MLT on its clinical effectiveness.

METHODS

Medical records of 42 consecutive eyes of 34 patients diagnosed with OAG who underwent MLT were retrospectively reviewed. The effectiveness was determined using the Kaplan-Meier survival analysis. Failure was defined as an intraocular pressure (IOP) reduction of <20% from baseline, an IOP >21 mm Hg during two consecutive follow-up visits, or surgical intervention for OAG. To determine the impact of MLT surgical expertise on clinical effectiveness, the eyes were divided into two groups according to whether the procedure was conducted by an experienced specialist (defined as a glaucoma specialist who had conducted at least ten MLT procedures) or a less experienced glaucoma specialist. The difference in expertise was determined using a log-rank test.

RESULTS

MLT was conducted by three glaucoma specialists. The overall survival rates were 0.76, 0.48, and 0.44 at 1, 3, and 6mo, respectively. The survival rates for MLT performed by a less experienced glaucoma specialist were 0.62, 0.31, and 0.25 (n=21 eyes) at 1, 3, and 6mo, respectively, whereas the survival rates for MLT performed by an experienced glaucoma specialist were 0.90, 0.64, and 0.64 (n=21 eyes) at 1, 3, and 6mo, respectively. The log-rank test showed a significant difference in the survival curves of the two groups (P=0.0061).

CONCLUSION

The 6-month effectiveness of MLT for controlling IOP is relatively limited in eyes with OAG using maximal tolerable glaucoma eyedrops. However, its effectiveness may be improved if performed by a glaucoma specialist with sufficient MLT experience.

MicroPulse® transscleral laser therapy in the management of glaucoma patients

OBJECTIVE

To evaluate the efficacy and safety of MicroPulse® transscleral laser therapy (TLT) in the management of glaucoma patients.

METHODS

A prospective, interventional, non-comparative case series was conducted in the department of ophthalmology, Ain Shams University Hospital on 61 eyes of 46 patients with various glaucoma types and of severity, ranging from mild to severe. In addition to best-corrected visual acuity (BCVA), intraocular pressure (IOP) and the number of glaucoma medications were recorded before and after treatment, along with the postoperative need for systemic carbonic anhydrase inhibitors (CAI), success rates, number of treatment sessions and postoperative complications. Success was defined as an IOP of 6-18mmHg or at least a 30% decrease from preoperative IOP in the absence of any vision-threatening complications during the 6-month follow-up period.

RESULTS

MicroPulse TLT was performed on 61 glaucomatous eyes. Eleven of the 61 eyes (18%) that did not achieve IOP between 6-18mmHg, or at least a 30% decrease from baseline at 6 months, had a repeat MicroPulse TLT session. At 6 months follow-up post a single MicroPulse TLT session, the mean IOP reduction was 35.9±14.2%; and 6 months after the second session, it was 36.2±17.5% (P<.001). The success rate after the first session was 73.8% which increased to 78.7% after the second session. The mean anterior chamber (AC) cell reaction was+1.9±.8 at 1 day,+1.0±.7 at 1 week, and+.2±.4 at 1 month postoperatively. No cells were detected in any of the cases at 3 and 6 months follow-up (P<.001). The average number of anti-glaucoma eye drops before MicroPulse TLT was 2.6±1.0. Postintervention, the average number of anti-glaucoma eye drops was 1.7±1.2, and sustained at 6 months follow-up after the last treatment session (P<.001). There were no significant complications were noted. One eye developed transient hypotony for 3 months after MicroPulse TLT.

CONCLUSIONS

MicroPulse TLT is safe and effective in lowering IOP in a variety of glaucoma types and severity.