Transscleral Cyclophotocoagulation Research Articles

Secondary developmental glaucoma in eyes with congenital aphakia.

Purpose:To describe the clinical spectrum and management of glaucoma in congenital aphakia.Methods:The demographics and clinical spectrum of eyes with congenital aphakia with and without glaucoma were compared, and management outcomes of congenital aphakia cases with glaucoma were studied retrospectively between April 2000 and June 2020.Results:There were a total of 168 eyes (84 subjects) with a diagnosis of congenital aphakia, of which 29 eyes of 18 subjects were diagnosed with glaucoma. Corneal opacity was the presenting complaint in 26/29 eyes with glaucoma and 139/139 eyes without glaucoma. The (interquartile range (IQR)) horizontal corneal diameter was 10.5mm (IQR, 9.0-12.5) and 8mm (IQR, 5-10) in eyes with and without glaucoma (P = 0.01), respectively. The median (IQR) axial length was 17.5mm (IQR, 13.5-19.5) and 15mm (IQR, 14-16) mm in eyes with and without glaucoma (P = 0.03), respectively. Nineteen eyes with glaucoma had adequate intraocular pressure (IOP) control with one medication. Three eyes underwent transscleral diode cyclophotocoagulation and maintained IOP without medications. Three eyes underwent trabeculectomy and trabeculotomy, trabeculectomy followed by penetrating keratoplasty, and trabeculectomy, respectively, of which two eyes became phthisical. At the last follow-up, the median (IQR) IOP was 14 mm Hg (IQR, 14-17) Hg. The median (IQR) follow-up duration was 4.53 months (IQR, 2.03- 48.06).Conclusion:One-fifth of the eyes with congenital aphakia had secondary developmental glaucoma. The corneal diameter and axial lengths were higher in the eyes with glaucoma compared to eyes without glaucoma. Medical management is the preferred short-term mode of IOP control. Transscleral cyclophotocoagulation may be preferred over surgical intervention.

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

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). 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. 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.

Surgical Outcomes of the Ahmed Valve Implantation Following Trans-scleral Cyclophotocoagulation

Purpose: To determine the intraocular pressure (IOP) lowering effect and complications of Ahmed valve implantation (AGV) in patients who underwent cyclophotocoagulation (CPC).Methods: Patients who underwent AGV after CPC in group 1, those who underwent CPC after AGV in group 2, and patients who underwent repeated CPC in group 3 were included in this retrospective observational study. Changes in IOP, number of glaucoma eye drops, and best corrected visual acuity (BCVA) were analyzed before and 1 week, 1 month, 3 months, 6 months, and 12 months after surgery, and postoperative complications were analyzed.Results: Eight patients in group 1, 10 patients in group 2, and seven patients in group 3 were included in the analysis. Preoperative IOP was 45.6 ± 15.5, 29.3 ± 5.6, and 43.4 ± 14.4 mmHg in the three groups, respectively, and the number of glaucoma eye drops was 3.8 ± 0.7, 3.9 ± 0.3, and 3.7 ± 1.0 in the three groups, respectively. At 12 months postoperatively, IOP decreased significantly in all three groups compared to preoperatively (all <i>p</i> < 0.05), and the number of glaucoma eye drops was also significantly reduced (all <i>p</i> < 0.05). Among patients with preoperative BCVA of 0.02 decimal or higher, postoperative BCVA decreased in two patients in group 2 and one in group 3 (<i>p</i> = 0.380). Hypotony occurred in one patient in group 1 and two patients in group 3 (<i>p</i> = 0.383), and among them, one patient in group 1 and one patient in group 3 progressed to the phthisis (<i>p</i> = 0.940).Conclusions: In patients whose IOP cannot be controlled after CPC, AGV is expected to be used as a relatively safe and effective treatment method for lowering IOP.

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.

Traumatic aniridia with extensive episcleral pigmentation: a case report

BackgroundTraumatic aniridia has been documented in eyes with a history of cataract extraction through a clear corneal wound. The proposed hypothesis is that the iris tissue was squeezed out from the corneal wound as it is a relative weak point. However, traumatic aniridia with extensive pigmentation of the episclera has never been reported.Case presentationA patient, who has surgical histories of trabeculectomy and cataract surgery many years ago, presented with refractory high intraocular pressure (IOP), almost complete loss of the iris, and diffuse pigmentation of the episclera after he had suffered from a contusion injury. In addition to numerous pigment particles and cells in the anterior chamber and a well-centered intraocular lens, protruding uvea tissue with overlying conjunctiva adjacent to the site of trabeculectomy was noted. Gonioscopy showed absence of the iris with clear view of the ciliary body.ConclusionsThe distinct presentation of this case indicates that the torn iris was displaced to the trapdoor instead of the clear cornea incision and was confined to the subconjunctival space. The scleral fistula serves as a less resistant point for releasing pressure compared to a healed corneal wound when the eye encounters a contusion injury. Further treatment options to lower IOP include repeated trabeculectomy, implantation of glaucoma drainage device, and endoscopic cyclophotocoagulation. Transscleral cyclophotocoagulation may be considered only after episcleral pigmentation has become less so as to avoid the risk of surface burn.

COVID-19 and the Rationale for Primary Selective Laser Trabeculoplasty and Diode Laser Transscleral Cyclophotocoagulation in Africa.

The recent COVID-19 pandemic has affected ophthalmologists’ practices worldwide. Consequent global drug shortages and the limitations of medical glaucoma treatments in sub-Saharan Africa have highlighted the need for innovation in global ophthalmology to provide accessible, affordable, and effective glaucoma care. The role of lasers rather than medications for glaucoma patients in developing nations is emerging. Since lasers are easier to master than glaucoma surgery, it is pertinent to discuss the primary use of lasers in treating glaucoma in such nations. In particular, selective laser trabeculoplasty and diode laser transscleral cyclophotocoagulation seem to present a promising future for the treatment of glaucoma in Africa. In this report, we provide an evidence-based discussion exploring the emerging role of lasers in Africa.

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.

First and second transscleral cyclophotocoagulation treatments provide similar intraocular pressure-lowering efficacy in patients with refractory glaucoma

PurposeThe aim of this study is to address the safety and effectiveness of a second continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) treatment by comparing its outcome against a first CW-TSCPC treatment in the same patients with refractory glaucoma.MethodsTwenty-one eyes with either primary or secondary glaucoma received a second CW-TSCPC laser session ≥ 3 months after the first treatment. 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 3 months. A complete slit-lamp examination was conducted to record for complications or other abnormal ocular findings. Success was defined as IOP between 6 and 21 mmHg and > 20% reduction in IOP with or without anti-glaucoma medications.ResultsAt 3 months follow-up of the first CW-TSCPC treatment, a 24.8% decrease in IOP was observed, whereas a 45.6% IOP decrease was observed 3 months post the second CW-TSCPC treatment. Visual acuity did not decrease, and no major complications were observed post either treatment within the follow-up period. Time to failure was 79.5 ± 24.6 and 77.1 ± 29.4, respectively (P = 0.955). No serious complications were observed.ConclusionA second CW-TSCPC treatment proved to be a safe and effective treatment option when the first CW-TSCPC treatment was insufficient in maintaining the desired IOP level for a prolonged time (mean time between both sessions 6.4 ± 8.0 months).

Outcomes of Surgical Interventions in Primary Congenital Glaucoma Patients.

The aim was to report long-term surgical success of primary congenital glaucoma (PCG) patients in Thailand. PCG patients who underwent one of the following primary operations: trabeculotomy, goniotomy, trabeculectomy, combined trabeculotrabeculectomy (CTT) and diode transscleral cyclophotocoagulation (TSCPC) between January 1992 and January 2018 were reviewed. Surgical success was defined as intraocular pressure (IOP) between 5 and 21 mm Hg with or without antiglaucoma medications. Failure was defined as IOP ≤5 or ≥21 mm Hg for 2 consecutive visits, or when an additional glaucoma surgery was required to control IOP. Survival curves were analyzed using multilevel mixed-effect Weibull model. A total of 81 eyes from 55 PCG patients were included. Surgical procedures involved 20 goniotomies, 15 trabeculotomies, 16 trabeculectomies, 15 CTT, and 15 TSCPC. Median follow-up time was 24 months (interquartile range: 9 to 60 mo). Overall success rates were 68.8% at 1 year, 63.8% at 3 years, and 53.7% at 5 years. All types of surgery except TSCPC had comparable cumulative 1 year success rates ranging from 78.5% to 83.3%. Cumulative success rates of trabeculotomy (80.05%) and CTT (79.4%) were maintained at 3 and 5 years and were the highest among all procedures at 5 years. TSCPC had a significantly lower success rate compared with other types of surgery (hazard ratio: 7.4 to 13.1, all P=0.01). All patients receiving primary TSCPC showed no success at 48 months. Primary trabeculotomy and primary CTT demonstrated the highest long-term success rates in PCG patients.

The surgical management of glaucoma: A review.

After a long period of little change, glaucoma surgery has experienced a dramatic rise in the number of possible procedures in the last two decades. Glaucoma filtering surgeries with mitomycin C and glaucoma drainage devices remain the standard of surgical care. Other newer surgeries, some of which are minimally or microinvasive glaucoma surgeries, target existing trabecular outflow, enhance suprachoroidal outflow, create subconjunctival blebs, or reduce aqueous production. Some require the implantation of a device such as the iStent, Hydrus, Ex-PRESS, XEN and PRESERFLO, whilst others do not-Trabectome, Kahook dual blade, Ab interno canaloplasty, gonioscopy-assisted transluminal trabeculotomy, OMNI and excimer laser trabeculotomy. Others are a less destructive variation of an established procedure, such as micropulse transscleral cyclophotocoagulation, endoscopic cyclophotocoagulation and ultrasound cycloplasty. Cataract surgery alone can be a significant glaucoma operation. These older and newer glaucoma surgeries, their mechanism of action, efficacy and complications are the subject of this review.

A review on technology and different probes in transscleral cyclophotocoagulation

Glaucoma is a chronic progressive optic neuropathy, characterised by retinal ganglion cell loss leading to optic nerve head changes and visual field defects. The control of intraocular pressure remains a key determinant factor in the management of glaucoma. Cyclodestructive procedures target the epithelium of ciliary processes, thereby reduces the aqueous formation. Cyclodestructive procedures have advanced from initial cyclodiathermy to micropulse diode laser cyclophotocoagulation (CPC). The various probes used in transscleral CPC (TSCPC) include G-probe delivery device and G-probe illuminate delivery device for continuous wave TSCPC and micropulse P3 probe for micropulse diode laser TSCPC. This review article provides details on design of probes and their technology.

Low-energy transscleral diode laser cyclophotocoagulation: is it effective?

Low-energy transscleral diode laser cyclophotocoagulation: is it effective?

Role of trans-scleral diode cyclophotocoagulation in refractory glaucoma: A large retrospective study

Role of trans-scleral diode cyclophotocoagulation in refractory glaucoma: A large retrospective study

Efficacy and safety of transscleral diode laser cyclophotocoagulation therapy in advanced glaucoma cases with good visual acuity

Efficacy and safety of transscleral diode laser cyclophotocoagulation therapy in advanced glaucoma cases with good visual acuity

Short-term safety and efficacy of combining phacoemulsification and SubCyclo laser

Aim To evaluate the safety profile and the short-term efficacy of combining subliminal transscleral cyclophotocoagulation laser to the phacoemulsification procedure in cases with mild to moderate glaucoma. Design Prospective, noncomparative, interventional study. Patients and methods In all, 21 eyes of 21 patients suffering from mild to moderate glaucoma underwent combined phacoemulsification and SubCyclo laser. Their preoperative and postoperative intraocular pressures (IOPs) were measured and compared. The number of IOP-lowering drops used preoperatively and postoperatively was also evaluated. The safety of the procedure was evaluated by means of documenting any intraoperative complication and postoperative visual acuity and adverse effects. Results The mean preoperative IOP was 18 mmHg (±5.26), which was then reduced to 13.5 mmHg (±5.97) at 1 day, 11.62 mmHg (±2.6) at 1 week, 12.26 mmHg (±2.91) at 1 month, and 13.2 mmHg (±5.21) at 3 months postoperatively. Conclusions Early results for this study showed that combined phacoemulsification with SubCyclo laser procedure could provide a satisfactory decrease of the IOP, and is a safe procedure, with low rates of serious adverse event profiles.

Outcomes of initial and repeat micro-pulse transscleral cyclophotocoagulation in adult glaucoma patients.

Background:Micro-pulse transscleral cyclophotocoagulation (MP-TSCPC) has continued to gain popularity as a treatment in adult glaucoma patients. Thus far there is limited evidence reporting the efficaciousness and safety of retreatment.Objective:To evaluate safety and efficacy of primary and repeat MP-TSCPC procedures.Methods:Thirty-four of 67 eyes who failed to achieve target IOP from initial MP-TSCPC underwent repeat MP-TSCPC and followed for a minimum of 6 months. All treatments were performed using the laser power of 2000 or 2250 mW, duration of 100–200 s, and a velocity 16–20 s per hemisphere swipe. Success criteria were defined as intraocular pressure (IOP) reduction of greater than 20% from baseline or any medication reduction without additional glaucoma procedures at 6 months after repeat MP-TSCPC. The 6-month success rate after repeat MP-TSCPC was also compared to that of initial MP-TSCPC in the same group of eyes.Results:Mean baseline IOP before the repeat MP-TSCPC was 23.0 + /- 5.3 on 3.0 + /- 1.4 medications. At 6 months, mean post-op IOP was 18.2 + /- 5.4 (21.9% reduction, p < 0.002), with mean medication staying relatively the same (p = .976). Success rate was increased from 23.5% to 44.1% with the repeat procedure compared to that of initial procedure (p = 0.123). Mean IOP reduction was also greater after repeat MP-TSCPC (18.7%, p < 0.002) when compared to initial MP-TSCPC (10.4%). No adverse events occurred.Conclusions:MP-TSCPC is a safe and effective non-invasive means to lower IOP in a variety of glaucoma patients. While over 50% (34/67) of eyes required repeat MP-TSCPC, repeat treatment resulted in greater success rates and IOP reduction without any adverse events when using the total energy between 112 and 150 J.

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).&#x0D; Aims: To evaluate the effectiveness of micropulse transscleral cyclophotocoagulation (mCPC) in the combined treatment of patients with secondary neovascular glaucoma.&#x0D; 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.&#x0D; 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.&#x0D; 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.

Primary slow-coagulation transscleral cyclophotocoagulation laser treatment for medically recalcitrant neovascular glaucoma

AimsTo report treatment outcomes of slow-coagulation continuous-wave transscleral cyclophotocoagulation (TSCPC) as an initial surgical intervention in patients with neovascular glaucoma (NVG).MethodsA retrospective study including 53 patients (mean age of 69.6±16.6...

A new approach for CW-TSCPC to improve its safety and efficacy in glaucoma treatment

The goal of our study was to compare the outcomes of transscleral diode cyclophotocoagulation using a new protocol with new settings. In fact, we targeted the ciliary body guided by transillumination, reduced the energy applied at each spot, and enlarged the treatment area posteriorly from the pars plicata to the pars plana. Data were collected retrospectively from two groups of glaucoma patients. The first group of patients underwent transscleral diode laser cyclophotocoagulation as usual, with one-row applications of a maximum of 1200mW of energy and a duration of 2000ms. The second group was treated in three rows, using the same settings as the first group. Transillumination was used continuously during all of our procedures, to focus accurately on the location of the ciliary body. Outcome measures included intraocular pressure (IOP) and visual acuity (VA) at baseline and at a minimum of 3 months postoperatively, as well as complications occurring up until last follow-up visit. Patients were considered successfully treated if their intraocular pressure was lowered by at least 25% compared to their baseline or if their intraocular pressure was less than 21mmHg after the procedure, with or without glaucoma medications. Sixty eyes were treated with the one-row protocol, followed by 508 eyes treated with the three-row protocol. The mean follow-up was 19 (range 3-31) months. Success rates were 62% and 86% for the one-row group and three-row group, respectively. The IOP decrease was 40.5% (a mean reduction from 37.5±8.1mmHg to 22.3±10.2mmHg) in the one-row group and 57.6% in the three-row group (mean reduction from 36.05±10.4mmHg to 15.7±7.3mmHg), which was statistically significant in each group (P=0.0001). Additionally, a significant improvement in efficacy was found in the 3-row compared to the 1-row group (P=0.0001) No significant difference was found in VA before or after the procedure or between the 2 groups. No serious complications were reported. Diode laser TSCPC is a practical, rapid and well-tolerated procedure. The treatment protocol used, with lower energy levels applied to the eye, guided systematically by transillumination and targeting a wider area, appears to be safer and more effective.

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.