Histologic Changes Following Continuous Wave and Micropulse Transscleral Cyclophotocoagulation: A Randomized Comparative Study

Cyclodestruction and cyclophotocoagulation: Where are we?

Cyclodestruction is a technique reserved for glaucomas not controlled with medical and surgical treatment and poor visual potential. During the last century, new cyclodestructive techniques were developed, including cyclophotocoagulation, and the use of continuous-wave diode laser transescleral cyclophotocoagulation (CW-TS-CPC) has become widespread. In recent decades, micropulse diode laser transescleral cyclophotocoagulation (MP-TS-CPC) was introduced. We review the cyclodestruction techniques since their origins and these two techniques of cyclophotocoagulation, which are currently the most widely used: how they are performed, their mechanisms of action and their effectiveness and efficacy. We also review the comparison between them and with other techniques.

Outcomes of slow coagulation transscleral cyclophotocoagulation in a predominantly African American glaucoma population

Purpose

To evaluate outcomes of slow coagulation transscleral cyclophotocoagulation (SC-TSCPC) in a primarily African American patient population with glaucoma.

Methods

A retrospective chart review was performed for 104 consecutive cases of SC-TSCPC by a single surgeon between November 6, 2019-September 7, 2023. Power ranged from 1150 to 1500 mW, duration was 4 s, and number of spots ranged from 10 to 25. Exclusion criteria were diagnosis of neovascular glaucoma, prior CPC, visual acuity (VA) of no light perception or unable to be assessed due to patient's mental status, aphakia, or follow-up <3 months. The primary outcome measure was surgical success defined as an intraocular pressure (IOP) of 6-21 mmHg with a ≥20 % reduction from baseline, no glaucoma re-operation, and no loss of light-perception. Secondary outcome measures included VA, glaucoma medication use, and post-surgical complications. Analysis was also stratified by lens status as literature suggests a greater IOP-lowering effect in pseudophakic eyes after CPC.

Results

There were 28 eligible patients (6 phakic, 22 pseudophakic) included in this analysis. Mean follow-up was 11.6 ± 8.3 months, and 14 patients had postoperative year 1 data available. The mean age was 75.2 ± 13.9 years, 42.9 % were female, and 92.9 % were African American, reflective of the demographics of the local community. The cumulative success rate was 68.5 % at 1 year and did not differ significantly between phakic and pseudophakic patients. Mean VA worsened from 20/600 preoperatively to 20/1050 at last follow-up (P = 0.04) and was marginally worse in the phakic group (P = 0.15). Mean IOP decreased from 31.1 ± 13.2 mmHg on 4.0 ± 1.5 medications preoperatively to 13.8 ± 7.1 mmHg on 2.6 ± 1.5 medications at last follow-up (P < 0.001; P < 0.01), with a more pronounced effect among pseudophakic patients. 85.7 % of patients had prolonged anterior chamber (AC) inflammation beyond 1 month, which persisted in 10.7 % at last follow-up. The cystoid macular edema (CME) rate was 21.4 %, with 10.7 % persistent at last follow-up.

Conclusions

SC-TSCPC is an effective, non-incisional IOP-lowering procedure in phakic and pseudophakic eyes that may not otherwise be ideal candidates for incisional glaucoma surgery. Pseudophakic eyes may experience larger reductions in IOP, however, laser settings can be titrated on a case-by-case basis depending on individual patients' goals. There was a higher incidence of prolonged AC inflammation and CME in our cohort compared to similar studies which report rates of 12.7 % and 2.7 %, respectively. Although the significance of such complications may differ based on the visual potential of each patient, these findings support existing literature that African American patients can have greater incidence of inflammation and subsequent sequalae after ocular surgery.

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.

Uveoscleral Outflow Routes after MicroPulse Laser Therapy for Refractory Glaucoma: An Optical Coherence Tomography Study of the Sclera

To analyze in vivo scleral changes induced by MicroPulse transscleral laser therapy (MP-TLT) in refractory glaucoma using anterior segment-optical coherence tomography (AS-OCT). Forty-two candidate patients for MP-TLT were consecutively enrolled and underwent AS-OCT at baseline and after six months. MP-TLT success was defined as an intraocular pressure (IOP) reduction by one-third. The main outcome measures were the mean superior (S-), inferior (I-), and total (T-) intra-scleral hypo-reflective space area (MISHA: mm2) and scleral reflectivity (S-SR, I-SR, T-SR; arbitrary scale) as in vivo biomarkers of uveoscleral aqueous humor (AH) outflow. The IOP was the secondary outcome. The relations between the baseline-to-six months differences (D) of DS-MISHA, DI-MISHA, and DT-MISHA and DS-SR, DI-SR, DT-SR, and DIOP, were investigated. At 6 months, the median IOP reduction was 21% in the failures and 38% in the successes. The baseline S-MISHA, I-MISHA, and T-MISHA did not differ between the groups, while S-SR and T-SR were higher in the successes (p < 0.05). At six months, successful and failed MP-TLTs showed a 50% increase in S-MISHA (p < 0.001; p = 0.037), whereas I-SR and T-SR reduced only in the successes (p = 0.002; p = 0.001). When comparing DS-MISHA, DI-MISHA, and DT-MISHA and DS-SR, DI-SR, and DT-SR, there were no significant differences between the groups. In the successful procedures, DIOP was positively correlated with DT-MISHA and DI-MISHA (ρ = 0.438 and ρ = 0.490; p < 0.05). MP-TLT produced potentially advantageous modifications of the sclera in refractory glaucoma. Given the partial correlation between these modifications and post-treatment IOP reduction, our study confirmed that the activation of the uveoscleral AH outflow route could significantly contribute to the IOP lowering after MP-TLT.

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.

Endocyclophotocoagulation Combined with Phacoemulsification in Glaucoma Treatment: Five-Year Results

BACKGROUND

this study aimed to assess the effectiveness and safety of phaco-endocyclophotocoagulation (phaco-ECP) in patients with glaucoma over five consecutive years.

METHODS

Thirty-eight patients (38 eyes) with primary and secondary glaucoma were enrolled to undergo phaco-ECP (Endo Optiks URAM E2, Beaver-Visitec International, Waltham, MA, USA). The primary outcome measures were intraocular pressure (IOP) reduction, success rates, glaucoma medication use, and visual acuity after phaco-ECP. An IOP reduction of 20% compared to the baseline value without re-intervention was considered a successful treatment. Complete success was defined as a cessation of antiglaucoma medications. Secondary outcome measures included intraoperative and postoperative complications. Measurements were performed preoperatively and in the first week and 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months postoperatively.

RESULTS

The mean ± SD values of IOP preoperatively, at 12, 24, 36, 48, and 60 months postoperatively were 22.6 ± 6.7 mmHg, 15.9 ± 3.9 mmHg (p < 0.001), 15.9 ± 2.9 mmHg (p < 0.001), 15.6 ± 2.7 mmHg (p < 0.001), 15.5 ± 3.8 mmHg (p < 0.001), and 15.2 ± 2.6 mmHg (p < 0.001), respectively. The mean IOP at the last follow-up was reduced by 32.7%. The decrease in the number of antiglaucoma medications was statistically significant at each follow-up visit compared to the baseline. The qualified success rate was 40.6%. All patients at the 60-month follow-up visit required the use of antiglaucoma medications-none of the patients achieved complete success. During the follow-up period, nine patients (28.3%) that required retreatment due to nonachievement of the target IOP were considered failures. Six patients (15.8%) were lost from the follow-up. A total of 23 patients were evaluated 60 months after their phaco-ECP. Complications directly associated with the procedure, such as corneal edema (25.6%), IOP spikes (20.5%), IOL dislocation (2.6%), and uveitis (12.8%), were observed in our patients. Hypotony was not observed in any of our patients.

CONCLUSIONS

The phaco-ECP procedure was effective, well-tolerated, and safe for reducing IOP in glaucoma patients with cataracts over a long-term follow-up. Randomized, larger-scale studies are required to validate the results obtained.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

Trabecular Meshwork Movement Controls Distal Valves and Chambers: New Glaucoma Medical and Surgical Targets

Herein, we provide evidence that human regulation of aqueous outflow is by a pump-conduit system similar to that of the lymphatics. Direct observation documents pulsatile aqueous flow into Schlemm's canal and from the canal into collector channels, intrascleral channels, aqueous veins, and episcleral veins. Pulsatile flow in vessels requires a driving force, a chamber with mobile walls and valves. We demonstrate that the trabecular meshwork acts as a deformable, mobile wall of a chamber: Schlemm's canal. A tight linkage between the driving force of intraocular pressure and meshwork deformation causes tissue responses in milliseconds. The link provides a sensory-motor baroreceptor-like function, providing maintenance of a homeostatic setpoint. The ocular pulse causes meshwork motion oscillations around the setpoint. We document valves entering and exiting the canal using real-time direct observation with a microscope and multiple additional modalities. Our laboratory-based high-resolution SD-OCT platform quantifies valve lumen opening and closing within milliseconds synchronously with meshwork motion; meshwork tissue stiffens, and movement slows in glaucoma tissue. Our novel PhS-OCT system measures nanometer-level motion synchronous with the ocular pulse in human subjects. Movement decreases in glaucoma patients. Our model is robust because it anchors laboratory studies to direct observation of physical reality in humans with glaucoma.

Outcomes of microPulse transscleral laser therapy in eyes with prior glaucoma aqueous tube shunt

PURPOSE

To evaluate the outcomes of micropulse transscleral laser therapy (MP-TLT) in patients with uncontrolled glaucoma and prior glaucoma aqueous tube shunt.

METHODS

In this single‑center, retrospective, interventional case series, eyes that underwent MP-TLT and had prior glaucoma aqueous tube shunt surgeries were included. The Cyclo Glaucoma Laser System (IRIDEX Corporation, Mountain View, CA, USA) with the MicroPulse P3 probe (version 1) was used. Post‑operative data were collected at day 1, week 1, and months 1, 3, 6, 12, 18, 24, 30 and 36.

RESULTS

A total of 84 eyes (84 patients) with mean age of 65.8 ± 15.2 years and with advanced glaucoma (baseline mean deviation -16.25 ± 6.80 dB and best-corrected visual acuity 0.82 ± 0.83 logMar) were included in the study. Baseline mean IOP was 19.95 ± 5.6 mm Hg with a mean number of medications 3.39 ± 1.02. There were statistically significant differences in IOP between baseline and all follow-up visits (p < 0.01 for all). The mean percentage of IOP reduction between baseline and different follow-up visits ranged from 23.4% to 35.5% (p < 0.01). There was a significant reduction of visual acuity (≥ 2-lines) at 1 year (30.3%) and 2 years (76.78%). There was a statistically significant reduction in the number of glaucoma medications between baseline and all follow-up visits after postoperative week 1 (p < 0.05 for all). No severe complications including persistent hypotony and related complications were observed. At the last follow-up visit, only 24 (28%) eyes out of 84 eyes remained in the study.

CONCLUSION

MP-TLT is an effective treatment for reducing IOP and decreasing the number of medications in patients with advanced glaucoma and prior glaucoma aqueous tube shunt.

Cyclophotocoagulation as a Minimally Invasive Treatment Option for Glaucoma

Historically, the complications and inadequate efficacy of prior cyclodestructive procedures limited their role in glaucoma management. Recent advances in treatment techniques and parameters for laser cyclophotocoagulation has expanded its role in today's glaucoma practice. This review summarizes the role of different cyclophotocoagulation techniques, including continuous wave transscleral cyclophotocoagulation and micropulse transscleral cyclophotocoagulation, in the management of glaucomatous optic neuropathy.

Slow-Coagulation Transscleral Cyclophotocoagulation Laser Treatment for Medically Uncontrolled Secondary Aphakic Adult Glaucoma

PRCIS

Slow-coagulation CW-TSCPC is an efficacious, relatively safe, and non-incisional laser treatment option as an initial surgical glaucoma management choice, in secondary aphakic adult glaucoma that is medically uncontrolled.

PURPOSE

This study evaluates the outcomes of slow-coagulation continuous wave transscleral cyclophotocoagulation (CW-TSCPC) laser for treating secondary aphakic adult glaucoma after complicated cataract surgery as a primary surgical intervention.

MATERIALS AND METHODS

A retrospective chart review of adult aphakic eyes with medically uncontrolled glaucoma underwent slow-coagulation CW-TSCPC as a primary surgical glaucoma intervention was performed. Surgical success was the primary outcome measure. Success was defined as postoperative intraocular pressure (IOP) between 6 and 21 mm Hg with ≥20% reduction compared with baseline and no need for further glaucoma surgeries or development of vision-threatening complications. The secondary outcomes included changes in IOP, glaucoma medication numbers, visual acuity, and postoperative complications during the first year after laser treatment after laser treatment.

RESULTS

This study included 41 eyes of 41 patients. The mean age of study participants was 66.7±13.1 years, with a mean follow-up duration of 19±3.5 months. At one year, the success rate was 63.4%. A statistically significant reduction of the IOP was observed, with the mean IOP decreasing from 29.6±5.8 mm Hg with a mean of 3.9±1.0 medications at baseline to a mean of 19.0±6.4 mm Hg with a mean of 2.5±1.2 medications at 12 months ( P <0.001). Four eyes received CW-TSCPC retreatment, and 2 eyes required incisional glaucoma surgeries. Reported postoperative complications included: visual acuity decline ≥2 lines in 7 eyes, iritis in 6 eyes, hyphema in 5 eyes, cystoid macular edema in 2 eyes, and transient hypotony in 1 eye.

CONCLUSION

Slow-coagulation CW-TSCPC is an efficacious, relatively safe, and non-incisional laser treatment option as an initial surgical glaucoma management choice, in secondary aphakic adult glaucoma that is medically uncontrolled.

Microcyclophotocoagulation in Glaucoma Treatment: A Medium-Term Follow-Up Study

BACKGROUND

This study aimed to assess the effectiveness and safety of transscleral microcyclophotocoagulation (µCPC) in patients with glaucoma for eighteen consecutive months.

METHODS

Sixty-one patients (64 eyes) with primary and secondary glaucoma were enrolled to undergo µCPC (diode laser FOX 810, A.R.C. Laser, Nuremberg, Germany). The primary outcome measures were intraocular pressure (IOP) reduction, success rates, glaucoma medication use, and visual acuity after µCPC. An IOP reduction of 20% compared to the baseline value without re-intervention was considered a successful treatment. Complete success was defined as cessation of antiglaucoma medications. Secondary outcome measures included intraoperative and postoperative complications. Measurements were performed preoperatively and at the first week, and 1, 3, 6, 12, and 18 months postoperatively.

RESULTS

The mean ± SD values of IOP preoperatively at 1 day, 1 week, 1, 3, 6, 12, and 18 months postoperatively were 25.1 ± 8.4 mmHg, 17.3 ± 4.5 mmHg (p < 0.001), 16.5 ± 6.1 mmHg (p < 0.001), 20.5 ± 8.3 mmHg (p < 0.001), 17.1 ± 6.2 mmHg (p < 0.001), 18.0 ± 7.1 mmHg (p < 0.001), 15.8 ± 3.2 mmHg (p < 0.001), and 17.0 ± 5.9 mmHg (p < 0.001), respectively. The mean IOP at the last follow-up was reduced by 32.5%. The decrease in the number of antiglaucoma medications was statistically significant at each follow-up visit compared to the baseline. The qualified success rate was 38.5%. Two patients at 18-month follow-up did not require the use of antiglaucoma medications-complete success rate-3.1%. During the follow-up period, twenty-five eyes (39.1%) that required retreatment due to nonachievement of the target IOP were considered as failures. Eleven patients (12 eyes-18.8%) were lost to follow-up. A total of 26 patients (27 eyes) were evaluated 18 months after µCPC. Hypotony was observed in one patient (1.6%) and uveitis in two patients (3.1%) after the procedure. There were no other significant intraoperative or postoperative complications observed.

CONCLUSIONS

The µCPC is well tolerated and safe for reducing IOP in glaucoma patients in medium-term follow-up; however, success is moderate. Randomized, larger studies are needed to confirm the obtained results.

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.

Proliferative Vitreoretinopathy Following Transscleral Diode Cyclophotocoagulation

PRCIS

Transscleral diode laser cyclophotocoagulation may trigger the development of proliferative vitreoretinopathy. Our article demonstrates one such case leading to tractional macula-off retinal detachment in a child with aphakic glaucoma.

PURPOSE

The purpose of this article is to describe a case of proliferative vitreoretinopathy (PVR) developing subsequent to transscleral diode laser cyclophotocoagulation (cyclodiode) in a pediatric patient with aphakic glaucoma. PVR most commonly occurs following rhegmatogenous retinal detachment repair; however, to the best of our knowledge, it has never been reported to appear after cyclodiode.

METHODS

Retrospective evaluation of case presentation and intraoperative findings.

RESULTS

A 13-year-old girl with aphakic glaucoma presented 4 months after cyclodiode of the right eye with a retrolental fibrovascular membrane and anterior PVR. The PVR extended posteriorly over the next month, after which the patient developed a tractional macula-off retinal detachment. Pars Plana vitrectomy was performed, confirming dense anterior and posterior PVR. A review of the literature suggests that an inflammatory cascade, similar to that seen in PVR development following rhegmatogenous retinal detachment, may occur from the destruction of the ciliary body by cyclodiode. As a result, fibrous transformation may occur, likely accounting for the cause of PVR development in this case.

CONCLUSION

The pathophysiology of PVR development remains unclear. This case demonstrates that PVR may occur following cyclodiode and should be considered during postoperative monitoring after this procedure.

[Cyclophotocoagulation - current applications and practical aspects]

Despite the advent of a large variety of minimally invasive glaucoma surgery (MIGS) techniques cyclophotocoagulation (CPC) remains a popular treatment option to lower intraocular pressure (IOP) in glaucoma patients. Guidelines for glaucoma treatment point to the rather unphysiological mode of action and, thus, recommend CPC mainly for refractory glaucoma and/or eyes with limited visual potential. The primary target of CPC is the pigmented secretory ciliary body epithelium resulting in a decreased production of aqueous humor. In addition, an increase of aqueous outflow may contribute to the IOP lowering. CPC is generally considered a low risk intervention. However, macular edema, prolonged intraocular inflammation, vision loss, hypotony, pain or phthisis occur at considerable rates. Over the past decades new promising modes of cyclophotocoagulation have evolved aiming at reducing the risk of adverse effects and improving the efficiency. This article provides an overview of the different currently available cyclophotocoagulation modes: Besides the classic transscleral continuous-wave cyclophotocoagulation it covers endoscopic cyclophotocoagulation, micropulse transscleral laser treatment and transscleral controlled cyclophotocoagulation. Various practical aspects of the treatment in light of the current literature are being discussed.

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.

Postoperative Pain after Different Transscleral Laser Cyclophotocoagulation Procedures

BACKGROUND

As the number of surgical options in glaucoma treatment is continuously rising, evidence regarding distinctive features of these surgeries is becoming more and more important for clinicians to choose the right surgical treatment for each individual patient.

METHODS

For this retrospective data analysis, we included glaucoma patients treated with either continuous wave (CW-TSCPC) or micropulse transscleral cyclophotocoagulation (MP-TSCPC) in an inpatient setting. Pain intensity was assessed using a numeric rating scale (NRS) ranging from 0 (no pain) to 10 (worst imaginable pain) during hospitalization. CW-TSCPC was performed using OcuLight^® Six (IRIDEX Corporation, Mountain View, CA, USA) and MP-TSCPC was performed using the IRIDEX^® Cyclo-G6 System (IRIDEX Corporation, Mountain View, CA, USA).

RESULTS

A total of 243 consecutive cases of TSCPC were included. Of these, 144 (59.26%) were treated with CW-TSCPC and 99 (40.74%) with MP-TSCPC. Using the univariable model, the risk for postoperative pain was observed to be lower in MP-TSCPC compared with CW-TSCPC (unadjusted: OR 0.46, 95% CI 0.24-0.84, p = 0.017), but this did not hold using the multivariable model (adjusted: OR 0.52, 95% CI 0.27-1.02, p = 0.056). Simultaneously conducted anterior retinal cryotherapy was associated with a higher risk for postoperative pain (OR 4.41, 95% CI 2.01-9.69, p < 0.001).

CONCLUSIONS

We found that the occurrence of postoperative pain was not different in CW-TSCPC compared with MP-TSCPC in a multivariable model. In cases of simultaneous anterior retinal cryotherapy, the risk for postoperative pain was significantly higher.

Micropulse Cyclophotocoagulation vs Selective Laser Trabeculoplasty: Effects on Corneal Endothelial Cells and Intraocular Pressure

Purpose

To evaluate the effects of micropulse transscleral cyclophotocoagulation (mCPC) and selective laser trabeculoplasty (SLT) on endothelial cell density (ECD) and reduction of the intraocular pressure (IOP) in patients with primary-open angle glaucoma (POAG).

Patients and Methods

In this observational, retrospective study, 40 eyes with POAG were included. Patients were divided into three groups-group I was treated with SLT (n = 13), group II was treated with mCPC (n = 13), and group III included age-matched patients with medically treated glaucoma (n = 14) (control group). In both treatment groups (SLT and mCPC) preoperative and postoperative findings of best-corrected visual acuity (BCVA), ECD, and IOP were compared to the control group.

Results

The mean time interval before and after the treatment was 215 ± 120 days in group I (SLT) and 273 ± 177 days in group II (mCPC). The follow-up for group III (control group) was 209 ± 103 days. In both treatment groups (SLT and mCPC) there was a statistically significant reduction of the IOP postoperatively (group I: 3.5 ± 3.7 mm Hg (p = 0.005) and group II: 4.3 ± 4.1 mm Hg (p = 0.003)). The mean IOP for group III was 12.9 ± 3.7 mm Hg at visit 1 and did not change significantly (p = 0.353) at visit 2. In all three groups, there was no statistically significant change in ECD at the last visit.

Conclusion

According to our results, both SLT and mCPC seem to be effective in lowering the IOP, without showing any statistically significant effect on ECD in patients with POAG.However, larger and longer-term studies are necessary to understand the effects of the SLT and mCPC procedures on ECD.

How to cite this article

Garip Kuebler A, Priglinger S, Reznicek L. Micropulse Cyclophotocoagulation vs Selective Laser Trabeculoplasty: Effects on Corneal Endothelial Cells and Intraocular Pressure. J Curr Glaucoma Pract 2023;17(1):40-43.

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.

The Histopathology of Two Eyes Enucleated after Continuous Transscleral and Micropulse Transscleral Cyclophotocoagulation for Refractory Secondary Glaucoma

INTRODUCTION

Cyclodestructive procedures, which target the nonpigmented epithelium of the ciliary body, have been utilized to treat recalcitrant glaucoma since the early 1930s. There are now various types of cyclophotocoagulation (CPC) available. The authors provide a retrospective description that details the histopathologic findings in 2 patients who underwent CPC for uncontrolled uveitic and neovascular glaucoma (NVG) with subsequent enucleation.

CASE PRESENTATIONS

Two enucleated globes from 2 patients with secondary refractory glaucoma underwent cilioablative therapy: one with uveitic glaucoma and a remote history of micropulse transscleral CPC (MP-TSCPC) and the other with NVG and a recent history of traditional continuous transscleral CPC (CW-TSCPC). The clinical histories are summarized, and light microscopy reviewed for degree of coagulative necrosis and inflammation of the ciliary body and surrounding structures, as well as the underlying pathology of the glaucoma.

CONCLUSION

Both patients ultimately experienced pain and vision loss with either a recrudescence of elevated intraocular pressure or inflammatory hypotony and subsequently underwent enucleation of the affected eye. One globe was enucleated shortly after CW-TSCPC and found to have near full-thickness coagulative necrosis of the pigmented and nonpigmented ciliary epithelium and ciliary muscle as well as necrosis of adjacent nontarget tissues with fibrin in the anterior chamber. The second patient underwent enucleation many months after MP-TSCPC with partial healing fibrosis of the ciliary body and some remaining viable ciliary processes. The histopathologic findings post-CPC may vary based on the method used and evolve over time; additional study is needed.

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.

Clinical outcomes of slow-coagulation continuous-wave transscleral cyclophotocoagulation laser for treatment of glaucoma

PURPOSE OF REVIEW

The complications and inadequate efficacy of prior cyclodestructive procedures limited their role in glaucoma management. Recent advances in treatment techniques and parameters for laser cyclophotocoagulation has expanded its role in today's glaucoma practice. In this review, we discuss the treatment outcomes of slow-coagulation continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) as a glaucoma surgical procedure for multiple types of glaucoma in lowering intraocular pressure (IOP).

RECENT FINDINGS

Slow-coagulation TSCPC is a relatively new technique for CW-TSCPC that, unlike the 'pop' power titration technique of laser energy delivery, aims to avoid the production of the 'pop' sound that signals explosive inflammatory energy delivery to the ciliary body and nearby tissue. In slow-coagulation TSCPC, laser energy is applied in a fixed and lower amount over a longer duration, compared with the conventional pop technique. This laser energy approach leads to more stable, reliable, titratable, and selective ciliary body ablation for control of IOP, especially relative to the controversial current use of micropulse TSCPC.

SUMMARY

Slow-coagulation CW-TSCPC can be used safely, efficiently, reproducibly, and efficaciously in wide range of glaucoma types including those with no history of incisional surgeries, good visual acuity, and medically refractory glaucomas.

2-Jahres-Ergebnisse nach transskleraler MicroPulse-Lasertherapie bei Patienten mit primärem Offenwinkelglaukom

Hintergrund Untersuchung der langfristigen Effizienz und Sicherheit der transskleralen Lasertherapie (TLT) mittels MicroPulse über 24 Monate bei Patienten mit primärem Offenwinkelglaukom (POWG).

Material und Methoden In dieser prospektiven interventionellen Fallserie wurden die Daten von 44 Augen von medikamentös behandelten POWG-Patienten ausgewertet, die eine MicroPulse-TLT erhielten, um eine weitere Senkung des Augeninnendrucks (IOD) zu erreichen. Es wurden die Reduktion des 24-h-IODs, der zirkadianen IOD-Fluktuationen und der IOD-Spitzen nach 3, 12 und 24 Monaten untersucht. Zudem sollten postoperative Komplikationen, die Misserfolgsquote und Einflussfaktoren auf den Therapieerfolg analysiert werden.

Ergebnisse Der IOD ist von 16,1 ± 3,4 mmHg präoperativ auf 13,0 ± 2,9 mmHg (n = 31; p < 0,001) nach 3 Monaten, 12,3 ± 3,0 mmHg (n = 27; p < 0,001) nach 12 Monaten und 13,1 ± 2,6 mmHg (n = 23; p < 0,001) nach 24 Monaten gesunken. Nach 24 Monaten erreichten 23 Augen (52%) ihren individuellen Zieldruck. Es traten keine schwerwiegenden postoperativen Komplikationen auf. Es konnten keine Einflussfaktoren auf den Therapieerfolg identifiziert werden. Das häufigste Therapieversagen war innerhalb der ersten 3 postoperativen Monate zu beobachten und blieb danach nahezu stabil.

Schlussfolgerung Die MicroPulse-TLT zeigt eine gute IOD-Senkung bei Patienten mit primärem Offenwinkelglaukom und maximal tolerierter drucksenkender Lokaltherapie, wobei etwa 50% der Augen ihren individuellen Zieldruck erreichten.

Management of a recurrent encapsulated bleb with a cost-effective non-valved glaucoma drainage device

Despite the advancements in the surgical management of glaucoma, childhood glaucoma remains a challenging surgical disease worldwide. An early adolescent boy with primary congenital glaucoma, status after glaucoma drainage device (GDD) implantation, on maximum medical therapy, was presented with a swelling in the superotemporal orbital region. The patient had undergone an uneventful GDD implantation 2 years prior to presentation. A similar swelling, which was diagnosed to be a Tenon's cyst, had been excised on three earlier occasions. Given that the repeat capsular excision would also have the same likelihood of failure, and poor intraocular pressure control, a non-valved, cost-effective Aurolab aqueous drainage implant (AADI, Aurolab, Madurai, India) implantation was done inferonasally. In this patient, AADI proved to be a safe and effective alternative for the known GDDs.

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.

Slow Coagulation Transscleral Cyclophotocoagulation for Postvitrectomy Patients With Silicone Oil-induced Glaucoma

PRECIS

Slow coagulation transscleral cyclophotocoagulation (TSCPC) is an effective and safe glaucoma surgery in patients with medically uncontrolled silicone oil (SO)-induced glaucoma.

PURPOSE

The purpose of this study was to report the outcomes of slow coagulation continuous wave TSCPC in patients with medically uncontrolled secondary glaucoma following pars plana vitrectomy (PPV) and intravitreal SO injection.

PATIENTS AND METHODS

This retrospective study enrolled patients with medically uncontrolled glaucoma secondary to PPV with SO injection who underwent TSCPC using slow coagulation TSCPC settings (power of 1250 mW and duration of 4 s). The primary outcome measure was surgical success at 12 months. Surgical success was defined as an intraocular pressure 6 to 21 mm Hg and reduced ≥20% from baseline, no reoperation for glaucoma, and no loss of light perception vision. Secondary outcome measures included number of glaucoma medications, visual acuity changes, and surgical complications.

RESULTS

A total of 18 eyes of 18 patients were included in the study. The mean age and follow-up of the patients were 51.94±14.5 years and 16.3±3.5 months, respectively. The mean intraocular pressure decreased from 29.7±9.6 mm Hg preoperatively to 14.6±6.5 mm Hg at 12 months postoperatively (P<0.001). Glaucoma medications were reduced from 4.2±0.9 at baseline to 1.9±1.3 at 12 months after TSCPC (P<0.001). A nonsignificant change of logarithm of the minimum angle of resolution visual acuity was observed at 12 months (P=0.722). The success rate at 12 months was 72.2%. No major complications were reported during the first year of follow-up.

CONCLUSION

Slow coagulation TSCPC had high efficacy and minimal complications when used as an initial glaucoma surgical procedure in patients with SO-induced glaucoma.

Treatment Outcomes of Slow Coagulation Transscleral Cyclophotocoagulation In Pseudophakic Patients with Medically Uncontrolled Glaucoma

PURPOSE

Reporting treatment outcomes of slow coagulation transscleral cyclophotocoagulation (TSCPC) as an initial surgical intervention in pseudophakic patients with glaucoma.

DESIGN

Retrospective case series.

METHODS

This single academic center study reviewed 74 pseudophakic patients who had a diagnosis of glaucoma and no previous glaucoma surgeries (mean age 82.6 ± 12.5 years; mean follow-up 18.7 ± 9.1 months). The intervention used was slow coagulation continuous wave TSCPC (1250-mW power and 4-second duration). The primary outcome measure was surgical success defined as an intraocular pressure (IOP) of 6-21 mm Hg with a ≥20% reduction from baseline, no reoperation for glaucoma, and no loss of light-perception vision. Secondary outcome measures included glaucoma medication use, visual acuity (VA), and complications.

RESULTS

IOP decreased from 27.5 ± 9.8 mm Hg preoperatively to 16.1 ± 6.3 mm Hg postoperatively (P < .001). The preoperative number of glaucoma medications was 4.1 ± 0.9 and 3.1 ± 1.3 post-TSCPC (P < .001). The cumulative probabilities of success at 1 and 2 years were 60.6 % and 58.5%, respectively. When patients were divided into 2 groups based on their baseline IOP being >21 mm Hg (high group) or ≤21 mm Hg (low group), success rates at 2 years were 64.9% and 45.5%, respectively (P = .144). The mean logarithm of the minimum angle of resolution VA changed from 0.70 ± 0.64 to 1.04 ± 0.87 at the last follow-up visit (P = .01). No serious complications were observed and most of the complications were mild and transient.

CONCLUSIONS

Slow coagulation TSCPC has good efficiency, especially in patients with baseline IOP >21 mm Hg, and safety profile as an initial surgical intervention in pseudophakic patients with glaucoma.

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.

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.

Correlation between intraocular pressure reduction and anterior chamber aqueous flare after micropulse transscleral cyclophotocoagulation

BACKGROUND

Micropulse transscleral cyclophotocoagulation (MP-CPC) is a technique that has been approved in recent years to treat glaucoma. MP-CPC causes anterior chamber inflammation; a relationship with reduced intraocular pressure (IOP) has not been reported. Therefore, we analyzed the correlation between IOP and anterior chamber aqueous flare after MP-CPC.

METHODS

This retrospective study included 37 eyes of 37 patients who underwent MP-CPC between November 2018 and October 2020. IOP and flare values were measured at 1, 4, and 12 weeks after MP-CPC. Correlations were assessed between the percentage IOP reduction and flare elevation by calculating Spearman's rank correlation coefficient.

RESULTS

The percentage IOP reduction at 1 week after surgery was correlated with the flare elevation at 1 week after surgery (ρ = 0.47, P = 0.006). The percentage IOP reduction at 12 weeks after surgery was correlated with the flare elevation at 4 weeks after surgery (ρ = 0.53, P = 0.006).

CONCLUSIONS

A short-term correlation was implied between reduced IOP and flare elevation after MP-CPC.

Micropulse trans-scleral laser therapy outcomes for uncontrolled glaucoma: a prospective 18-month study

OBJECTIVE

To evaluate the efficacy and safety of micropulse trans-scleral laser therapy (mTLT) in glaucomatous patients.

DESIGN

Prospective, interventional study in a university hospital setting.

PARTICIPANTS

Fifty-two eyes of 52 adult patients with uncontrolled glaucoma despite maximal tolerated medical treatment, and/or poor candidates for filtering surgery.

METHODS

Participants received a 360-degree mTLT diode laser treatment (2000mW, 31.33% duty cycle), with duration adjusted to iris pigmentation and glaucoma severity (160-320 seconds). They were followed for 18 months to assess intraocular pressure (IOP), number of medications, corrected distance visual acuity (CDVA), glaucoma progression based on Humphrey Sita 24-2 perimetry and Cirrus high-definition optical coherence tomography, and complications. The primary outcome measure was the absolute success at 18 months. Absolute success was defined as an IOP 6-21 mm Hg and at least 25% IOP reduction, with equal or less number of IOP medications. Qualified success allowed for an increased number of IOP medications. Failure was defined as an inability to meet the criteria for success or the need for incisional glaucoma surgery.

RESULTS

Treatment absolute success was 61.5% at 12 months and 59.6% at 18 months. Mean IOP was reduced by 35.6% at 18 months (23.6 ± 6.5 mm Hg at baseline; 15.2 ± 4.1 mm Hg at 18 months, p < 0.001). mTLT did not significantly reduce the number of topical glaucoma medications (p = 0.075); however, 15 eyes (29%) had systemic oral glaucoma treatment at baseline and 10 eyes (20%) at 18 months. Eight patients (15%) experienced vision loss of ≥2 lines after the procedure. Three patients (6%) regained their preoperative CDVA by 1 month, and 3 patients (6%) by 3 months, while 2 patients (4%) sustained persistent visual loss. No ocular complications were noted in 84.6%. Incisional surgery was required in 25% of eyes owing to inadequately controlled glaucoma despite mTLT.

CONCLUSIONS

mTLT is a good therapeutic option for moderate IOP reduction, while being safe and predictable. This improved safety profile makes mTLT a treatment to be considered earlier in the management of glaucoma.

One-Year Follow-up of Pars Plicata Versus Pars Plana Application of Transscleral Micropulse Cyclophotocoagulation

PURPOSE

To compare the efficacy and safety of micropulse transscleral cyclophotocoagulation applied at the level of the pars plicata transscleral micropulse cyclophotocoagulation (PLI-MPC) versus the pars plana transscleral micropulse cyclophotocoagulation (PLA-MPC).

METHODS

This prospective interventional case series included 44 eyes of 31 medically treated primary open-angle glaucoma patients scheduled for micropulse transscleral cyclophotocoagulation to achieve further intraocular pressure (IOP) reduction. In total, 22 eyes underwent PLI-MPC and PLA-MPC each. Primary endpoints were the reduction of 24-hour mean diurnal IOP (mean of 6 measurements), diurnal IOP fluctuations, and peak IOP, after 3 and 12 months. Secondary outcomes were postoperative complications, a possible deterioration in visual acuity and field, factors influencing IOP reduction, and the number of dropouts.

RESULTS

In the PLI-MPC group, IOP was reduced from 15.9±3.4 mm Hg to 13.6±3.1 mm Hg (n=16; P<0.001) and 12.9±3.7 mm Hg (n=13; P<0.001) at 3 and 12-month follow-up. In the PLA-MPC group, IOP decreased from 16.4±3.5 mm Hg to 12.3±2.6 mm Hg (n=15; P<0.001) and 11.8±2.2 mm Hg (n=14; P<0.001), respectively. At 12 months, 59% of the PLI-MPC and 63% of the PLA-MPC group had a sufficient IOP reduction to reach the individual target pressure. No complications were seen in either group. A higher preoperative IOP was recognized as the only factor influencing the postoperative IOP reduction.

CONCLUSIONS

PLI-MPC and PLA-MPC seem to be safe and effective in further lowering the IOP in about 60% of patients with primary open-angle glaucoma who did not reach target pressure despite maximally tolerated IOP-lowering medication. Although the IOP-lowering effect was not statistically significantly different between groups the pars plicata application was superior and easier to perform and should be recommended as the preferred method of application.