Micropulse transscleral cyclophotocoagulation using a standard protocol in patients with refractory glaucoma naive of cyclodestruction

The effect of cumulative energy in repeated subliminal transscleral cyclophotocoagulation: a retrospective study

BACKGROUND

The long-term safety and efficacy of repeated applications of subliminal transscleral cyclophotocoagulation (SL-TSCPC) with a focus on cumulative energy was evaluated in glaucoma patients.

METHODS

In this retrospective, multicentric study the data of a total of 82 eyes with various causes of glaucoma that were treated with a single or multiple applications of SL-TSCPC were collected. Treatments were performed under general or local anesthesia with an 810 nm diode laser. Power was 2000 mW; duty cycle, 31.3%; total treatment duration, 80-320 s; equaling a total energy of 50-200 J per treatment session. Fifty-five eyes (55 patients) presented for all follow-ups, and these eyes were selected for further statistical analysis. The mean age was 60.0 ± 17.1 years, and 22 (40%) of the patients were female. Intraocular pressure (IOP) and dependence on further glaucoma medication were evaluated at 12 months following the initial treatment.

RESULTS

Eyes underwent 1 or 2 consecutive SL-TSCPC treatments. Median (min-max) baseline IOP of 34 (13-69) decreased to 21.5 (7-61), 22 (8-68), 20 (9-68), and 19.5 (3-60) mmHg at the 1, 3, 6, and 12-month postoperative timepoints respectively. The mean (± SD) IOP decrease at 12 months was 26 ± 27%, 39 ± 32%, and 49 ± 33% in the low (below 120 J, n = 18), medium (120-200 J, n = 24), and high (above 200 J, n = 13) cumulative energy groups respectively. At the 12-month timepoint, oral carbonic anhydrase use was discontinued in ¾ of the cases.

CONCLUSIONS

It was found that the repeated application of SL-TSCPC safely and efficiently decreases IOP in a Caucasian population with heterogenous causes of glaucoma, eyes with silicone oil responded to a greater extent. Inclusion of cumulative energy scales may contribute to better addressing repeated procedures in a standardized fashion.

Cyclodiode vs micropulse transscleral laser treatment

BACKGROUND

Continuous-wave transscleral cyclophotocoagulation (CW-TSCP) is usually reserved for advanced/refractory glaucoma. Micropulse transscleral laser therapy (MPTLT) utilises short energy pulses separated by 'off'-periods. MPTLT is postulated to have fewer complications, but its relative efficacy is not known. The National Institute for Health and Care Excellence (NICE) has deemed the evidence supporting MPTLT use of inadequate quality, limiting its use to research. This study aims to evaluate MPTLT efficacy and safety compared to CW-TSCP.

METHODS

This 24-month follow-up retrospective audit included 85 CW-TSCP and 173 MPTLT eyes at a London tertiary referral centre. Primary outcome was success rate at the last follow-up; defined as at least 20% intraocular pressure (IOP) reduction with the same/fewer medications, and IOP between 6 and 18 mmHg. Secondary outcomes were acetazolamide use and success rates per glaucoma type. Safety outcomes were reported as complication rates.

RESULTS

By 24-months, mean IOP reduced from 34.6[±1.4]mmHg to 19.0[ ± 3.0]mmHg post-CW-TSCP (p < 0.0001); and from 26.1[±0.8]mmHg to 19.1[±2.2]mmHg post-MPTLT (p < 0.0001). Average IOP decreased by 45.1% post-CW-TSCP, and 26.8% post-MPTLT. Both interventions reduced medication requirements (p ≤ 0.05). More CW-TSCP patients discontinued acetazolamide (p = 0.047). Overall success rate was 26.6% for CW-TSCP and 30.6% for MPTLT (p = 0.83). Only primary closed-angle glaucoma saw a significantly higher success rate following CW-TSCP (p = 0.014). CW-TSCP complication rate was significantly higher than MPTLT (p = 0.0048).

CONCLUSION

Both treatments significantly reduced IOP and medication load. CW-TSCP had a greater absolute/proportionate IOP-lowering effect, but it carried a significantly greater risk of sight-threatening complications. Further prospective studies are required to evaluate MPTLT compared to CW-TSCP.

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.

Update on Diagnosis and Treatment of Uveitic Glaucoma

Glaucoma is a common and potentially blinding complication of uveitis. Many mechanisms are involved alone or in combination in the pathogenesis of uveitic glaucoma (UG). In terms of diagnostic evaluation, the effects of inflammatory activity in the retinal nerve fiber layer may be a source of bias in the interpretation of optical coherence tomography measurements. For the successful treatment of UG, the control of intraocular inflammation specific to the cause or anti-inflammatory treatment, combined with IOP management, is mandatory. The early institution of specific treatment improves the prognosis of UG associated with CMV. The young age of UG patients along with increased failure rates of glaucoma surgery in this group of patients warrants a stepwise approach. Conservative and conjunctival sparing surgical approaches should be adopted. Minimally invasive surgical approaches were proved to be effective and are increasingly being used in the management of UG along with the traditionally used techniques of trabeculectomy or tubes. This review aims to summarize the progress that recently occurred in the diagnosis and treatment of UG.

[Current views on pathogenesis and treatment of neovascular glaucoma]

Neovascular glaucoma is a type of secondary glaucoma characterized by the most severe course, and ranking second among the causes of irreversible blindness. This review summarizes the results of numerous studies devoted to the search for prevention measures and the most effective treatment strategy. The main ways of preventing the development of neovascular glaucoma are timely diagnosis and elimination of ischemic processes in the retina, combined with adequate control of intraocular pressure and treatment of the underlying disease.

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.

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.

Real-world outcomes of micropulse cyclophotocoagulation in a Latin American population and analysis of the factors associated with the success rate

OBJECTIVE

To report the outcomes of micropulse cyclophotocoagulation in a Latin American population with refractory glaucoma in a "real-world" setting and to evaluate the factors associated with success after a one-year follow-up.

MATERIALS AND METHODS

Retrospective, multicenter study. The medical records of patients who underwent micropulse cyclophotocoagulation between September 2017 and October 2018 were reviewed. Treatment success was defined as an intraocular pressure of 5 to 21 mmHg or a 20% intraocular pressure reduction with or without additional glaucoma medical therapy.

RESULTS

Eighty-three eyes from 83 patients were included, with a mean follow-up of 10.1 ± 3.1 months. The intraocular pressure and number of glaucoma medications significantly decreased at all postoperative visits from a mean of 21.9 ± 7.6 mmHg on 3.8 medications to 13.1 ± 3.5 mmHg on 2.8 medications at the 12-month follow-up. The mean intraocular pressure decreased 40.1% from baseline at 12 months. The cumulative success rate was 54.5% (95% CI, 44-67%) at 12-month follow-up. We identified a higher baseline intraocular pressure as a significant independent predictor of treatment success (p = 0.03). Late complications included 1 eye with corneal edema, 1 eye with prolonged anterior chamber inflammation and cystoid macular edema and 9 eyes (11%) with visual loss of 2 Snellen lines or more.

CONCLUSIONS

Micropulse cyclophotocoagulation is an effective and safe treatment for Latin American patients and can provide intraocular pressure and medication reductions with a single treatment after a one-year follow-up. A high baseline intraocular pressure was the most significant predictor of treatment success.

The mechanism and therapeutic strategies for neovascular glaucoma secondary to diabetic retinopathy

Neovascular glaucoma (NVG) is a devastating secondary glaucoma characterized by the appearance of neovascular over the iris and the proliferation of fibrovascular tissue in the anterior chamber angle. Proliferative diabetic retinopathy (PDR) is one of the leading causes of NVG. Currently increasing diabetes population drive the prevalence rate of NVG into a fast-rising lane. The pathogenesis underlying NVG makes it refractory to routine management for other types of glaucoma in clinical practice. The combination of panretinal photocoagulation (PRP), anti-vascular endothelial growth factor (VEGF) injections, anti-glaucoma drugs, surgical intervention as well as blood glucose control is needed. Early diagnosis and aggressive treatment in time are crucial in halting the neovascularization process and preserving vision. This review provides an overview of NVG secondary to diabetic retinopathy (DR), including the epidemiology, pathogenesis and management, so as to provide a better understanding as well as potential therapeutic strategies for future treatment.

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.

Estimating the Ideal Treatment Protocol and Success Predictors for Double-session Micropulse Transscleral Laser for Glaucoma Management

Aim

To identify the ideal treatment protocol and success predictors for double-session micropulse transscleral (MP3) laser for glaucoma management.

Materials and methods

Patients who underwent double-session MP3, with a minimum follow-up of 6 months, were retrospectively investigated. Logistic regression analysis was used to verify preoperative success predictors. The following comparisons were made: (1) Between eyes that obtained surgical success vs failure, (2) According to the time required for MP3, and (3) Considering only eyes that required retreatment.

Results

A total of 191 eyes from 148 patients were included. The preoperative intraocular pressure (IOP) was significantly higher than at last follow-up visit (27.3 ± 6.9 vs 14.6 ± 6.0 mm Hg, p < 0.001). Success was observed in 90.5% of the eyes. On logistic regression analysis with preoperative IOP and MP3 time as independent variables, only previous IOP was identified as a statistically significant factor (p = 0.004), with lower IOP relating to higher success. Eyes that required lower MP3 time underwent more MP3 procedures than those with higher MP3 time (1.2 ± 0.5 vs 1.1 ± 0.3, p = 0.03). In the 36 eyes that underwent retreatment, preoperative IOP was higher (31.6 ± 7.4 vs 26.3 ± 6.4 mm Hg, p < 0.001); eyes with successful IOP treatment had a higher MP3 treatment time at the first surgery than eyes with failed IOP correction (364.1 ± 68.2 vs 330.0 ± 18.0 seconds, p = 0.02).

Conclusion

Thus, an ideal double-session MP3 protocol should use a high laser energy at the first surgery, and a high preoperative IOP can be considered as a predictor of surgical failure.

Clinical significance

This is the first study to give special attention to the double-session MP3 protocol and success predictors.

How to cite this article

Magacho L, Lima FE, Ávila MP. Estimating the Ideal Treatment Protocol and Success Predictors for Double-session Micropulse Transscleral Laser for Glaucoma Management. J Curr Glaucoma Pract 2022;16(2):111-116.

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.

Efficacy and safety of subliminal transscleral cyclophotocoagulation in uncontrolled glaucoma

Purpose

To determine the efficacy of subliminal cyclophotocoagulation in reducing intraocular pressure (IOP) and to assess the safety profile of the procedure.

Methods

We reviewed the charts of all patients who underwent subliminal cyclophotocoagulation between August 2019 and August 2020. The IOP, number of antiglaucoma medications, and visual acuity were compared at baseline and at 6 months. The post-laser complications were noted. Paired t-test, Wilcoxon rank-sum test, and McNemar test were used for analysis.

Results

This study included 40 eyes of 40 patients. The most frequent diagnosis was neovascular glaucoma (55%), followed by primary open-angle glaucoma (17.5%). The mean IOP reduced from 32 to 21 mmHg (mean IOP reduction: 32%, 95% confidence interval [CI]: 27%-37%, P < 0.001). Mean number of antiglaucoma medications declined from 3.2 to 1.9 (P < 0.001). Use of oral acetazolamide decreased from 62% to 5% (P < 0.001). The success rate of the procedure at 6 months was 55%. One patient had unexplained visual acuity decline after the procedure.

Conclusion

Subliminal sub-cyclophotocoagulation is effective in treating refractory glaucoma in the Indian population. It decreases the medication burden. However, subliminal lasers can also cause vision-threatening complications such as hypotony, uveitis, and optic nerve hypoperfusion. So, clinicians should be cautious when using sub-cyclophotocoagulation in patients with good vision.

Choroidal Thickness Increase after Subliminal Transscleral Cyclophotocoagulation

Background: The purpose of this study is to estimate the success rate of subliminal transscleral cyclophotocoagulation for refractory glaucoma and to determine the correlation between the decrease in intraocular pressure and the variation in choroidal thickness. Methods: A pre−post study was conducted over a period of 3 years, including 81 eyes from 67 patients with different types of drug-refractory glaucoma who underwent subliminal transscleral cyclophotocoagulation. The variables included best-corrected visual acuity, intraocular pressure and choroidal thickness. Results: We observed the following success rates (defined as IOP < 21 mmHg): 80% at 1 month (65 patients), 74% at 3 months (60 patients), 64% at 6 months (52 patients) and 50.6% at 1 year (41 patients). A strong correlation was noted between the decrease in intraocular pressure and the increase in the average choroidal thickness at 1 year (318.42 µm) compared to the average preoperative thickness (291.78 µm). A correlation of increased choroidal thickness at 1-month with the success rate of the procedure was also observed. Conclusions: We observed a statistically significant correlation between the success rate, decrease in intraocular pressure and choroidal thickness. The correlation of increased choroidal thickness at 1-month with the success rate of the procedure could be used clinically as a predictive factor for the final outcome of patients. Further experimental research is warranted to determine whether the increase in choroidal thickness after subliminal transscleral cyclophotocoagulation is indeed evidence of increased uveoscleral drainage.

Efficacy and Safety of Micropulse Transscleral Laser Therapy in Silicone Oil-induced Glaucoma

PURPOSE

To assess the efficiency and safety of MicroPulse® Transscleral Laser Therapy (TLT) in the management of silicone oil-induced glaucoma.

METHODS

A prospective case series of 33 eyes with uncontrolled silicone oil-induced glaucoma was enrolled at the department of ophthalmology of Mohamed Taher Maamouri Hospital, Nabeul, Tunisia. Patients were treated with MicroPulse TLT using the IRIDEX Cyclo G6® Glaucoma Laser System with the MicroPulse P3® fiberoptic handheld probe. Patients underwent complete ophthalmologic examination during the 12-month follow-up period.

RESULTS

The study included 33 eyes of 33 patients. The mean age was 50.39 years old. We included patients with silicone oil-induced glaucoma. Silicone oil tamponade was indicated for complicated rhegmatogenous retinal detachment in 22 cases, diabetic tractional retinal detachment in 10 cases, and post-traumatic retinal detachment in one case. Silicone oil was already removed before the procedure in 23 eyes. Silicone oil tamponade duration varied between 3 to 26 months. IOP measurements at enrolment, day 1, day 7, day 15, 1 month, 3 months, 6 months and 12 months was respectively 37.94±13.61, 19.03±10.98, 16.5±6.17, 19.45±9.73, 19.27±8.33, 19.39±9.52, 19.97±10.03 and 19.7±9.58▒mmHg. The percentage of IOP lowering was 45.38% at 6 months and 45% at 12 months. The success rate was 93.93% at 6 months remaining stable at 12 months. No major side effects were observed, in particular, no phthisis bulbi nor prolonged inflammation. There was no difference in IOP lowering between patients with silicone oil or those after silicone oil removal (P=0.99).

CONCLUSION

MP-TLT was safe and effectively lowered intraocular pressure in uncontrolled silicone-oil induced glaucoma.

Comparison of Aqueous Flare Values after Micropulse Transscleral Laser Treatment and Continuous Wave Transscleral Cyclophotocoagulation

PURPOSE

The purpose of this study was to analyse the changes in flare values after Micropulse Transscleral Laser Treatment for Glaucoma (MP-TLT) in patients with refractory glaucoma and to compare with the outcomes of patients who underwent continuous wave (CW) diode laser cyclophotocoagulation (CW-TSCPC).

METHODS

In this single-centre study, we reviewed the medical records of 54 patients who underwent MP-TLT and 35 patients who underwent CW-TSCPC at Ankara University Faculty of Medicine, Department of Ophthalmology. Aqueous flare values were measured by laser flare photometry.

RESULTS

The mean laser flare values in both groups (MP-TLT/CW-TSCPC) increased after surgery from 20.85 ± 8.74/22.14 ± 7.39 ph/ms at baseline to 48.52 ± 18.23/57.38 ± 20.08 ph/ms (P = .001) on day 1 and then progressively decreased to 44.13 ± 18.32/52.24 ± 20.56 in week 1, 40.5 ± 18.5/48.24 ± 19.23 week 2 and 35.28 ± 17.09/41.11 ± 16.7 month 1 (all p < .05) and returned to similar levels to baseline at month 3 and month 6 (both p > .05). Patients who achieved treatment success had significantly higher flare values than patients who failed on post-operative day 1, week 1 and week 2 in both groups. The flare values were significantly lower in the MP-TLT group than the CW-TSCPC group on post-operative day 1, week 1, week 2 and month 1 (all p < .05). There were no cases of prolonged post-operative inflammation or serious complications in both groups.

CONCLUSION

Intraocular inflammation, quantified by aqueous flare, may be a contributing factor to the IOP lowering effect of transscleral diode laser cyclophotocoagulation in the early post-operative period.

Micropulse vs. continuous wave transscleral cyclophotocoagulation in neovascular glaucoma

Neovascular glaucoma (NVG) is a refractory form of glaucoma, associated with important morbidity, for which no consensus exists regarding the optimal choice of therapy. The primary aim of our study was to compare the performances of micropulse transscleral cyclophotocoagulation (MP-TSCPC) and continuous wave transscleral cyclophotocoagulation (CW-TSCPC) in the treatment of neovascular glaucoma (NVG). A total of 24 eyes for MP-TSCPC and 22 eyes for CW-TSCPC, all with NVG were included. The procedures were performed using either the Iridex Cyclo G6 (IRIDEX Laser System), the MP3, or the G-Probe devices. Intraocular pressure (IOP), visual acuity (VA), the mean number of antiglaucoma medications, and postoperative complications were monitored. The minimum follow-up was 12 months. The success rate at 12 months was 54.5% in the CW-TSCPC group and 33.3% in the MP-TSCPC group. The mean IOP at baseline was 35.82 mm Hg for CW-TSCPC and 34.71 mm Hg for MP-TSCPC. The change from baseline in IOP at 12 months was 11.95 mm Hg in the CW-TSCPC group and -8.04 mm Hg in the MP-TSCPC group. There was a significant difference in the occurrence of serious complications (worsening of VA, hypotony, and phthisis bulbi) between the two methods, with CW-TSCPC associated with more important adverse effects (P=0.045). There was a decrease in the number of topical antiglaucoma medications in both groups: in the MP-TSCPC group from a mean number of 2.6 at baseline, to 1.7 at 3 months, followed by a slight increase to 2.1 at 12 months and in the CW-TSCPC group from 2.8 at baseline, to 1.4 at 3 months and 1.9 at 12 months. Our study concluded that both MP-TSCPC and CW-TSCPC could manage NVG, but, while CW-TSCPC revealed higher IOP control in the long term (which did not reach statistical significance), it also had a significantly lower safety profile.

The study of the efficiency of micropulse transscleral cyclophotocoagulation in the combined treatment of patients with secondary neovascular glaucoma

Background: Neovascular glaucoma (NVG) is a highly refractory form, it is characterized by fast development and a high level of the intraocular pressure (IOP). Aims: To evaluate the effectiveness of micropulse transscleral cyclophotocoagulation (mCPC) in the combined treatment of patients with secondary neovascular glaucoma. Methods: The study included 32 patients (32 eyes) with secondary NVG as an outcome of diabetes mellitus and (or) thrombosis of the central retinal vein or its branches. The preoperative IOP averaged 38.88.8 mm Hg with the most intense hypotensive therapy. All the patients underwent mCPC. In the postoperative period, the patients were examined on the first day after the operation, then in 1 week, 1, 3, 6 months, 1 year after the operation. Results: All the operations were performed without complications. Pain syndrome in all cases was stopped on the first day after surgery. Six patients had reactive hypertension on the first day, therefore, the hypotensive therapy was intensified. The IOP 1 week after mCPC was 20.97.9 mm Hg, after 1 month of observation 23.76.0 mm Hg with the hypotensive therapy. 34 weeks post-surgery, six patients with the preserved visual function experienced a repeated IOP increase, and the Ahmed valve was implanted. 6 months after mCPC, the IOP level averaged 22.87.7 mm Hg with the hypotensive therapy. Against the background of the IOP compensation, anti-VEGF drugs were injected in 4 cases, followed by laser coagulation of the retina. Conclusion: Application of mCPC in NVG glaucoma patients showed only a small number of postoperative complications. This method of laser treatment can be used in combination with panretinal laser coagulation before or after the surgery, including administration of anti-VEGF drugs before or after the surgery. In case of the IOP increase, mCPC may be repeated.

Micropulse Transscleral Cyclophotocoagulation as Primary Surgical Treatment for Primary Open Angle Glaucoma in Taiwan during the COVID-19 Pandemic

Glaucoma is the leading cause of irreversible blindness worldwide, with primary open angle glaucoma (POAG) accounting for the greatest number of total glaucoma cases. This study aimed to evaluate the efficacy and safety of micropulse transscleral cyclophotocoagulation (MP-TSCPC) as a primary procedure in POAG during the COVID-19 pandemic. We retrospectively analyzed 60 eyes of 52 patients, who were diagnosed with mild-to-end-stage POAG without previous glaucoma surgery and received MP-TSCPC between 1 January 2020 and 31 August 2020. The mean preoperative intraocular pressure (IOP) significantly decreased from 27.8 mm Hg to 19.8, 20.1, 20.3, 20.4, and 20.2 mm Hg at 1, 3, 6, 9, and 12 months, respectively (all p < 0.05). The mean number of IOP-lowering medications used significantly decreased from 3.3 at the baseline to 1.6, 1.8, 1.8, 1.9, and 1.9 at 1, 3, 6, 9, and 12 months, respectively (all p < 0.001). Total withdrawal of antiglaucoma medications was fulfilled in five patients. The main outcome was achieved in 81.7% at postoperative month 12. The most common adverse effect was transient mydriasis (28.3%). No major complications were encountered. MP-TSCPC seems to be an effective and safe treatment to reduce IOP and the medication burden with minimal vision-threatening complications in mild-to-end-stage POAG patients without previous glaucoma surgery.

Blue Sclera as a Complication of Micropulse Transscleral Laser Therapy

We report 3 patients who underwent micropulse laser therapy for glaucoma and subsequently developed a bluish-black discoloration of the sclera in a semicircular pattern corresponding to the probe path. This complication has not yet been reported with the micropulse laser treatment.

Micropulse transscleral cyclophotocoagulation in a Taiwanese population: 2-year clinical outcomes and prognostic factors

PURPOSE

To evaluate the 2-year efficacy and safety of micropulse transscleral cyclophotocoagulation (MP-TSCPC) in Taiwanese patients with glaucoma.

METHODS

We included the patients who received standardized MP-TSCPC with follow-up examinations on a regular basis for 24 months. Treatment success was defined as the attainment of a postoperative intraocular pressure (IOP) between 6 and 21 mmHg or a ≥ 20% reduction in IOP from baseline without an increase in glaucoma medications.

RESULTS

A total of 60 eyes from 56 patients who underwent MP-TSCPC for refractory glaucoma were included. The median age at MP-TSCPC intervention was 58.9 ± 12.4 years. The percentage of treatment success was 88.3% at 3 months, 83.3% at 6 months, 78.3% at 12 months, and 75.0% at 24 months. The mean baseline IOP prior to MP-TSCPC was 34 ± 11.9 mmHg (range 14-56 mmHg). The mean postoperative IOP decreased to 20.9 ± 10.0 mmHg, 18.0 ± 7.8 mmHg, 17.5 ± 6.4 mmHg, and 18.2 ± 7.1 mmHg after 3 months, 6 months, 12 months, and 24 months, respectively, in successful cases. The mean number of glaucoma medications at baseline was 3.8 ± 0.2, and the mean numbers of glaucoma medications at postoperative months 3, 6, 12, and 24 were 2.6 ± 0.7, 2.8 ± 0.6, 2.5 ± 1.4 and 2.6 ± 1.4, respectively, in successful cases. Younger age and prior CW-TSCPC significantly contributed to surgical failure in the multivariate model. Complications after MP-TSCPC included mild anterior chamber inflammation, conjunctival hemorrhage, hypotony, and mydriasis, and all subsided after treatment. None of the eyes developed vitreous hemorrhage, cystoid macular edema, or phthisis bulbi in the late postoperative period.

CONCLUSIONS

This study demonstrated that younger age and prior CW-TSCPC were risk factors for MP-TSCPC failure within 2 years. MP-TSCPC might be safe and effective for refractory glaucoma patients with maximal antiglaucoma medications.

Efficacy, Safety, and Retreatment Benefit of Micropulse Transscleral Cyclophotocoagulation in Glaucoma

PRECIS

Micropulse transscleral cyclophotocoagulation (MP-TSCPC) with a 120-second setting reduces intraocular pressure (IOP) with a 6-month success of 45.5%. Only late (>6 mo) failure seem to present a benefit for retreatment.

PURPOSE

The purpose of this study was to assess MP-TSCPC efficacy, safety, factors of success, and retreatment benefit in open-angle glaucoma.

PATIENTS AND METHODS

A retrospective consecutive case series study. We included patients with open-angle glaucoma who were naive of a cycloablative procedure and underwent MP-TSCPC at 2000 mW for 120 seconds between May 1, 2017, and October 31, 2019. Success was defined as IOP >5 and ≤21 mm Hg with IOP reduction ≥20% from baseline, without any retreatment and visual acuity better than negative light perception. MP-TSCPC retreatment was early and late, before and after 6 months postoperatively, respectively.

RESULTS

We included 94 eyes in 94 patients [mean (SD) age: 67.2 (13.4) y; 47.9% women]. The mean preoperative IOP was 24.9 (7.1) mm Hg and was reduced to 18.9 (6.3) at month 6 (P<0.0001). The success rate decreased progressively over time and reached 45.5% at 6 months. Patients with 6-month surgical success had lower mean axial length than others [24.1 (1.5) vs. 25.5 (2.1) mm, P=0.05]. In patients with early and late MP-TSCPC retreatment, the 6-month success rate was 16.7% and 63.6%, respectively.

CONCLUSIONS

MP-TSCPC performed with a 120-second setting reduced IOP, with 45.5% success at month 6 and few complications. Axial length was newly described as affecting success, probably linked to the ciliary-body position. Retreatment seemed to be of little benefit in nonresponders or those with early failure. Further studies on laser settings and ciliary-body location are required to find the best risk-benefit protocol.

Micropulse Transscleral Cyclophotocoagulation

How to cite this article: Abdelmassih Y, Tomey K, Khoueir Z. Micropulse Transscleral Cyclophotocoagulation. J Curr Glaucoma Pract 2021;15(1):1–7.

One year Outcomes of Micropulse Cyclophototherapy for Primary Open Angle Glaucoma

PRCIS

In primary angle open glaucoma, micropulse trans-scleral cyclophototherapy is effective in lowering intraocular pressure but its effects are not permanent. Hence, it can serve as a temporizing measure prior to definitive glaucoma surgery.

PURPOSE

There is limited data on micropulse trans-scleral cyclophototherapy(MPTCP) in POAG. This is the first study that looks at MPTCP treatment specifically in POAG patients.

PATIENTS AND METHODS

This is an interventional, single institution exploratory case series with 55 eyes of 48 patients with POAG. Data was collected from clinical records, including patient demographics, clinical information, number of glaucoma medications, MPTCP laser settings, complications and clinical outcomes.

RESULTS

Patients had a mean age of 67.3±14.1 years with a preponderance of males. IOP was 24.8±1.0 mmHg before MPTCP and decreased to 19.5±1.1mmHg, 21.7±1.1mmHg and 21.6±1.1▒mmHg at postoperative month 3, 6 and 12 respectively. IOP remained below pretreatment levels throughout the postoperative period(P<0.05). VA and MD remained stable before and after MPTCP. No eyes had complications. Number of glaucoma medications remained the same after MPTCP. 4 eyes required additional oral acetazolamide at postoperative month 1 for IOP control. 17 eyes subsequently required further surgical intervention after 9.84 months. Maximal IOP decrease was greater when there were higher power settings, higher preoperative IOP and better preoperative VA.

CONCLUSIONS AND RELEVANCE

The IOP lowering effect of MPTCP treatment in patients with POAG was found to be modest and transient with similar medication burden, and definitive glaucoma surgery was needed in a number of patients.

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.

[Transscleral laser therapy in the treatment of glaucoma]

Nowadays glaucoma is one of the leading causes of irreversible blindness worldwide. The main goal in preservation of vision in glaucoma patients is reducing intraocular pressure (IOP), which is considered the main controlled risk factor for progression of glaucomatous optic neuropathy. The article discusses the effectiveness and safety of various transscleral laser technologies in the treatment of glaucoma. Modern transscleral laser technologies that affect the uveoscleral drainage and scleral hydro-permeability are less traumatic and more gentle making them promising in the treatment of patients with early stages of glaucoma, and not only in terminal glaucoma with pain syndrome resistant to conventional treatment ("last resort surgery").