Efficacy of Goniotomy With Kahook Dual Blade in Patients With Uveitis-associated Ocular Hypertension:

Outcomes of Micropulse Transscleral Cyclophotocoagulation in Uveitic Glaucoma

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A Rare Case of Postoperative Uveitis and Obstructive Peripheral Anterior Synechiae Following Combined OMNI Canaloplasty and Hydrus Microstent Implantation

Purpose

This study seeks to highlight and explore the occurrence of uveitis with obstructive peripheral anterior synechiae (PAS) after a combined OMNI canaloplasty and Hydrus microstent implantation with phacoemulsification, particularly in a patient with a background of psoriatic arthritis.

Observations

A 56-year-old male with a medical history of psoriatic arthritis (in remission for 10 years) and primary open-angle glaucoma (POAG) underwent a combined OMNI canaloplasty and Hydrus microstent with phacoemulsification. The surgical procedure was uncomplicated. However, within 2 weeks postsurgery, the patient presented with severe symptoms, including uveitis, elevated intraocular pressure (IOP), and a significant reduction in best-corrected visual acuity (BCVA). This postoperative response was unexpected, especially given the lack of any past history of uveitis in the patient. The complication, potentially influenced by the patient's history of psoriatic arthritis, led to the need for additional interventions, including the implantation of an Ahmed glaucoma valve.

Conclusion

This case underscores the potential for postoperative complications, specifically uveitis with obstructive PAS, following combined OMNI canaloplasty and Hydrus microstent with phacoemulsification, especially in patients with a history of autoimmune diseases. Careful preoperative history, postoperative monitoring, and a nuanced approach to surgical planning are crucial. The association between systemic inflammatory conditions and ocular complications warrants deeper exploration to ensure optimal patient care.

How to cite this article

Dossantos J, An J. A Rare Case of Postoperative Uveitis and Obstructive Peripheral Anterior Synechiae Following Combined OMNI Canaloplasty and Hydrus Microstent Implantation. J Curr Glaucoma Pract 2024;18(1):37-41.

[Ab interno trabeculotomy without/with cataract operation-An alternative treatment before or instead of trabeculectomy in patients with high intraocular pressure?]

BACKGROUND

Trabeculotomy with the Kahook knife is a new ab interno minimally invasive glaucoma surgery (MIGS) procedure. The MIGS are usually performed in early to intermediate glaucoma eyes. In this retrospective study we analyzed the intraocular pressure (IOP) and topical glaucoma eye drop therapy (Meds) reduction achieved by the Kahook trabeculotomy (TO) without (n = 19) or with (n = 18) combined cataract operation (Cat-TO) as initial treatment before or to avoid filtering surgery.

MATERIAL AND METHODS

A total of 37 eyes of 37 patients were examined when IOP was > 21 mm Hg in at least 2 examinations despite the maximum tolerable Meds applied. Cat-TO was performed in 18 phakic eyes (primary open-angle glaucoma, POAG = 11, pseudoexfoliation glaucoma, PEX = 5, ocular hypertension, OHT = 2). In 19 pseudophakic eyes (POAG = 12, PEX = 6, OHT = 1) an isolated TO was executed. Complete success (no Meds) and relative success (irrespective of Meds) for IOP ≤ 21 mm Hg, ≤ 18 mm Hg, ≤ 16 mm Hg were evaluated 2, 6 and 12 months postoperatively.

RESULTS

The IOP was significantly reduced from preoperatively to 2 months after Cat-TO as well as after TO (Cat-TO: 26.8 ± 5.9 mm Hg to 16.0 ± 2.9 mm Hg, p < 0.001; TO: IOD 28.2 ± 5.6 mm Hg to 16.3 ± 3.5 mm Hg, p < 0.001). Meds reduction after Cat-TO as well as after TO was not significant (Cat-TO: 2.1 ± 1.3 to 1.3 ± 1.3, p = 0.11; TO: Meds 2.7 ± 1.1 to 2.2 ± 1.3, p = 0.23); however, Meds reduction after 6 and 12 months was significantly greater in the Cat-TO group compared to the TO group (p = 0.02). The IOP and Meds did not change significantly from 2 to 6 months. After Cat-TO, qualified success after 12 months for IOP ≤ 18 mm Hg was 61% (11/18) and for IOP ≤ 16 mm Hg 28% (5/18). After TO, qualified success after 12 months for TO was 47% (9/19) for IOP ≤ 18 mm Hg and 26% (5/19) for IOP ≤ 16 mm Hg. The intervention was not sufficient for 7 patients after TO and 2 patients after Cat-TO (IOP two times > 21 mm Hg).

CONCLUSION

The first year results show that TO as well as Cat-TO are effective minimally invasive interventions to delay or even avoid a filtrating operation. In case of Meds intolerance and target IOP ≤ 16 mm Hg Cat-TO is not sufficient.

Gonioscopy-Assisted Transluminal Trabeculotomy and Goniotomy, With or Without Concomitant Cataract Extraction, in Steroid-Induced and Uveitic Glaucoma: 24-Month Outcomes

PRCIS

Gonioscopy-assisted transluminal trabeculotomy (GATT) and goniotomy with Kahook Dual Blade both achieved sustained reductions in intraocular pressure (IOP) and medication burden in eyes with steroid-induced or uveitic glaucoma at 24 months. Both procedures had favorable safety profiles.

PURPOSE

To characterize the 24-month surgical outcomes of GATT and excisional goniotomy in eyes with steroid-induced or uveitic glaucoma.

PATIENTS AND METHODS

A retrospective chart review was performed of eyes with steroid-induced or uveitic glaucoma that underwent GATT or excisional goniotomy, either standalone or combined with phacoemulsification cataract surgery, by a single surgeon at the Cole Eye Institute. IOP, number of glaucoma medications, and steroid exposure were recorded preoperatively and at multiple postoperative timepoints up to 24 months. Surgical success was defined as at least 20% IOP reduction or IOP <12, 15, or 18 mm Hg (Criterion A, B, or C). Surgical failure was defined as need for additional glaucoma surgery or loss of light perception vision. Intraoperative and postoperative complications were reported.

RESULTS

Forty eyes of 33 patients underwent GATT, and 24 eyes of 22 patients underwent goniotomy, of which 88% and 75%, respectively, had 24-months' follow-up. Concomitant phacoemulsification cataract surgery was performed in 38% (15/40) GATT eyes and 17% (4/24) goniotomy eyes. IOP and number of glaucoma medications were reduced at all postoperative timepoints in both groups. At 24 months, GATT eyes had mean IOP 12.9±3.5 mm Hg on 0.9±1.2 medications, and goniotomy eyes had mean IOP 14.3±4.1 mm Hg on 1.8±1.3 medications. Surgical failure was 8% for GATT and 14% for goniotomy at 24 months. Transient hyphema and transient IOP elevation were the most common complications, and 10% GATT eyes required surgical evacuation of hyphema.

CONCLUSIONS

Both GATT and goniotomy demonstrate favorable efficacy and safety in steroid-induced and uveitic glaucoma eyes. Both procedures achieved sustained reductions in IOP and glaucoma medication burden at 24 months.

Surgical outcomes of excisional goniotomy using the kahook dual blade in severe and refractory glaucoma: 12-month results

OBJECTIVES

To describe the efficacy and safety of goniotomy with trabecular meshwork excision using the Kahook Dual Blade (KDB, New World Medical Inc., Rancho Cucamonga, CA) in patients with severe or refractory glaucoma.

METHODS

This retrospective multicentre case series reports on 40 eyes with severe or refractory open-angle glaucoma that underwent standalone or combined KDB goniotomy and were followed for 12 months post-operatively in the United-States, Mexico and Switzerland. Surgical success was defined as an intraocular pressure (IOP) reduction ≥20% from baseline at 12 months, with fewer medications than preoperatively. Mean IOP and antiglaucoma medication reduction, probabilities of achieving an IOP ≤16 or 18 mmHg, and adverse events were also analysed.

RESULTS

Mean IOP decreased from 18.1 ± 5.0 mmHg at baseline to 14.8 ± 3.7 mmHg at 12 months (18.2% reduction, P < 0.001). Concomitantly, the mean number of glaucoma medications decreased from 2.5 ± 1.4 to 1.7 ± 1.2 (32% reduction, P = 0.002). The proportion of eyes achieving an IOP reduction of more than 20% from baseline was 37.5% (n = 15) at 12 months. At 12 months, 67.5% and 82.5% achieved a medicated IOP ≤ 16 and ≤18 mmHg, respectively. No severe complications were reported.

CONCLUSION

Excisional goniotomy with KDB achieves a statistically significant IOP and antiglaucoma medication reduction in severe or refractory glaucoma over a period of 12 months. While its efficacy decreases with time, its favourable safety profile makes it a potentially useful primary or adjunctive procedure in high-risk eyes.

Risk factors for Baerveldt glaucoma drainage implantation for uveitic glaucoma

Uveitic glaucoma (UG) is sometimes intractable, including intricate interaction between intraocular pressure (IOP) elevation associated with inflammation and side effects of steroids. Based on the Tube Versus Trabeculectomy study in refractory glaucoma results in 2012, tube shunt surgeries have been performed for UG, but few reports have focused on UG. We retrospectively examined the surgical efficacy, complications, and risk factors in 62 eyes with UG that underwent Baerveldt glaucoma drainage device (BGD) implantation at Kumamoto University. The IOPs significantly dropped, and the mean number of glaucoma medications was reduced by more than two. Kaplan‒Meier survival curves were presented under 2 conditions: an IOP reduction of 20% and 6 ≤ IOP ≤ 18 mmHg (criterion A) or 6 ≤ IOP ≤ 15 mmHg (criterion B). In criterion A, the median survival times (MST) were 124 days (complete) and 997 days (qualified). In criterion B, the MST was 129 days (complete) and 867 days (qualified). The Cox hazard proportional model found that the hazard ratio was 0.170 for a history of cataract surgery (95% CI 0.0303-0.950) and 8.669 for systemic immunosuppressive therapy (95% CI 1.810-41.51). BGD implantation is effective for treating UG, but the presence of systemic treatment and the lens status should be considered.

Outcomes and risk factors for ab interno trabeculotomy with a Kahook Dual Blade

PURPOSE

To verify the surgical results and risk factors for ab interno trabeculotomy using a Kahook Dual Blade (KDB-LOT) in patients with various glaucoma types.

METHODS

This study was a retrospective case series of 205 eyes that underwent KDB-LOT. For Kaplan-Meier survival analysis, criterion A was defined as a ≤ 20% reduction in intraocular pressure (IOP) from baseline. Criteria B, C, and D were IOPs of ≤ 21, 18, and 15 mmHg, respectively. The Cox proportional hazard (CPH) model investigated prognostic factors.

RESULTS

The mean (SD) IOP decreased from 24.7 (7.98) to 17.6 (4.80) mmHg in all cases, from 21.3 (6.88) to 17.8 (3.52) mmHg in primary open-angle glaucoma (POAG), from 25.4 (7.32) to 17.1 (4.65) mmHg in exfoliation glaucoma, from 30.6 (8.88) to 17.8 (8.29) mmHg in uveitic glaucoma, and from 30.8 (7.29) to 17.3 (0.83) mmHg in steroid-induced glaucoma at 1 year after KDB-LOT. The Kaplan-Meier survival analysis showed that patients with POAG had the best prognosis under criteria B and C, and the 1-year survival rate in patients under criterion D was less than 35% for any disease type. CPH analysis revealed that age and KDB-LOT with phacoemulsification were good prognostic factors. Risk factors for surgical failure were previous cataract surgery, selective laser trabeculoplasty, and postoperative peripheral anterior synechiae.

CONCLUSION

KDB-LOT was effective in treating patients with several glaucoma types but showed difficulty in pushing IOP below 15 mmHg. Prognostic factors should be considered when making decisions regarding surgical indications.

Extreme intraocular pressure and steroid-dependent iritis

A 50-year-old ophthalmic technician was referred by her retina specialist for urgent consultation due to markedly elevated intraocular pressure (IOP) unresponsive to medical therapy. Her history included chronic polyarticular juvenile rheumatoid arthritis and chronic uveitis requiring ongoing topical steroid therapy. She had a sub-Tenon injection of Kenalog (triamcinolone) 18 months prior to referral. Chronic topical anti-inflammatory therapy included nepafenac (Ilevro) and prednisolone acetate 2 times a day. Attempts to discontinue topical steroid resulted in worsening inflammation. The patient was referred when the IOP measured 44 mm Hg in the left eye despite aggressive medical therapy, including acetazolamide. The IOP improved slightly when loteprednol was substituted for prednisolone acetate. Current medications in the left eye include brimonidine 3 times a day, loteprednol 2 times a day, nepafenac 2 times a day, and fixed combination latanoprost + netarsudil at bedtime. Her only medication in the right eye was travoprost. She is intolerant to dorzolamide. She was also taking acetazolamide 500 mg 2 times a day. She was not taking any anticoagulants. Past surgical history included cataract surgery in each eye. She has not had laser trabeculoplasty in either eye. Examination revealed uncorrected visual acuity of J1+ in the right eye (near) and 20/30 in the left eye (mini-monovision). There was no afferent pupillary defect. There was mild band keratopathy in each eye while the central cornea was clear in both eyes without keratic precipitates. Here angles were open to gonioscopy without peripheral anterior synechia. There was mild to moderate flare in each eye with trace cells. The IOP was 17 mm Hg in the right eye and 31 mm Hg in the left. Central corneal thickness measured 560 μm and 559 μm in the right and left eye respectively. There was a well-positioned intraocular lens within each capsule with a patent posterior capsulotomy. There was mild vitreous syneresis but no vitreous cell. The cup to disc ratio was 0.5 in each eye with a symmetrical neural rim. The retina was flat without macular edema. Visual field was normal in both eyes (Figures 1 and 2). Optical coherence tomography of retinal nerve fiber layer (RNFL) is shown in Figure 3 and retinal ganglion cell layer is shown in Supplemental Figure 1 (http://links.lww.com/JRS/A756).JOURNAL/jcrs/04.03/02158034-202301000-00020/figure1/v/2022-12-26T045736Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202301000-00020/figure2/v/2022-12-26T045736Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202301000-00020/figure3/v/2022-12-26T045736Z/r/image-tiff Please comment on your management of this patient's left eye.

Outcomes of Kahook Dual Blade Goniotomy for Uveitis Associated Open Angle Glaucoma or Ocular Hypertension

PRCIS

Kahook Dual Blade (KDB) goniotomy can successfully lower intraocular pressure in some patients with uveitis-associated ocular hypertension or glaucoma.

PURPOSE

The purpose of this study was to report a case series of patients that underwent KDB goniotomy at a single institution for uveitis-associated ocular hypertension or glaucoma with an open angle.

METHODS

We performed a retrospective chart review of all patients with uveitis-associated ocular hypertension or glaucoma who underwent KDB goniotomy with trabecular meshwork excision alone or in combination with phacoemulsification cataract surgery at a single center between August 2017 and February 2020. The case series included 45 eyes of 37 patients. All eyes developed ocular hypertension refractory to maximum-tolerated medical therapy and required surgical intervention. Two eyes were excluded as they were lost to follow-up before 5 months postoperatively. Surgical success was defined as reaching the goal intraocular pressure or lower for each patient, including ongoing medical therapy.

RESULTS

At most recent follow-up, 25 (55.6%) of 45 eyes had an intraocular pressure that was at goal. Mean follow-up time was 15.2±12.1 months ranging from 0.5 to 36 months postoperatively, considering that patients were eliminated from the data analysis once they required a second surgery. The mean number of preoperative medications, including oral carbonic anhydrase inhibitors was 3.7±1.2 medications. The mean number of postoperative medications through the last clinic visit was 2.5±1.9 medications for a mean reduction of 1.2±1.6 medications ( P -value <0.0001*).

CONCLUSIONS

This larger case series shows that some patients with uveitis-associated ocular hypertension or glaucoma with an open angle may have success with KDB goniotomy.

Ab Interno Goniotomy with the Kahook Dual Blade in a Monocular Patient with Mucous Membrane Pemphigoid and Refractory Open Angle Glaucoma: A Case Report

Purpose

To describe the case of a monocular patient with ocular mucous membrane pemphigoid (MMP) and open angle glaucoma refractory to medical treatment, who was successfully managed with ab interno goniotomy at the time of cataract surgery.

Methods

A 63-year-old woman with a history of severe MMP presented with exacerbation of the disease in both eyes. Vision was 20/80 in the right eye and light perception in the left eye. Symblepharon formation, trichiasis and forniceal foreshortening were present in the right eye, while the cornea of the left eye was completely conjunctivalized. Following aggressive systemic immunosuppressive therapy with corticosteroids and cyclophosphamide, the disease was brought under control. However, the patient developed a mature cataract and high intraocular pressure (IOP) of 28 mmHg on maximal medical therapy. Due to the high risk of ocular MMP exacerbation with glaucoma filtration surgery, the decision was made to proceed with cataract extraction combined with ab interno goniotomy with the Kahook Dual Blade.

Results

There were no intraoperative complications. The IOP has remained in the 12–14 mmHg range without any topical glaucoma medications over a total follow up of 3.5 years.

Conclusion

Ab interno goniotomy using the Kahook Dual Blade can significantly reduce IOP and medication burden in MMP cases, where any type of conjunctival incisional surgery could induce disease flare up. In this case, it represented a safe and effective surgical procedure for ocular MMP with concomitant refractory open angle glaucoma.

Outcomes of Microhook ab Interno Trabeculotomy in Consecutive 36 Eyes with Uveitic Glaucoma

Microhook trabeculotomy (μLOT), recently developed by Tanito belongs to minimally invasive glaucoma surgery and contributes to intraocular pressure (IOP) control in eyes with glaucoma resistant to medical therapy. In this study, we aimed to investigate the effectiveness and safety of μLOT for uveitic glaucoma. The medical records of consecutive 36 eyes from 30 patients who underwent μLOT and were followed up over post-operative 1 year were reviewed. The surgical success (IOP = 5–20 mmHg and ΔIOP ≥ 20% with additional anti-glaucoma drugs) was achieved in 67% of eyes at post-operative 12 months. The median IOP significantly decreased from 30.5 mmHg pre-operatively to 15 mmHg at 12 months post-operatively (p = 0.001), and the median glaucoma drug score changed from 5 pre-operatively to 2.5 at 12 months post-operatively (p = 0.301). Intraocular inflammation scores at post-operative 6 weeks did not show a significant worsening as compared to pre-operatively, and 8 (22%) eyes exhibited exacerbation of inflammation during the 12-month follow-up period. Post-operative complications were confirmed in 58% of eyes, but most of them were mild and transient or successfully managed. With its favorable benefit–risk profile, μLOT would be an option worth considering as the first glaucoma surgery for uveitic glaucoma.

A Review of Excisional Goniotomy Performed with the Kahook Dual Blade for Glaucoma Management

Aim

To review the published literature describing clinical outcomes of excisional goniotomy using the Kahook Dual Blade (KDB) for the management of glaucoma.

Background

A family of less invasive glaucoma procedures—including excisional goniotomy with the KDB—has been developed to provide moderate reductions in intraocular pressure and/or medication burden in eyes with therapeutic needs that may not warrant the risks associated with more traditional procedures such as trabeculectomy and tube-shunt implantation. This review's goal is to synthesize the existing literature into a compendium of excisional goniotomy's indications, technique, efficacy and safety outcomes, and optimal place in glaucoma management.

Review results

Excisional goniotomy with the KDB effectively lowers IOP and reduces the medication burden in eyes with POAG and other forms of glaucoma across the spectrum of both baseline IOP and disease severity. The procedure exhibits a safety profile that is on par with other angle-based surgical interventions and enhanced safety compared to filtration procedures. It can be performed by comprehensive ophthalmologists as well as glaucoma specialists. This procedure as a standalone operation delivers IOP reductions consistent with filtration surgery, and in combination with cataract surgery delivers both IOP and medication reductions at least as great as other minimally invasive procedures.

Conclusion

Given the broad base of evidence supporting its use in a wide variety of clinical scenarios, excisional goniotomy with the KDB can play a meaningful role in the achievement of patient-specific glaucoma therapy goals.

Clinical significance

These aggregate findings support the efficacy and safety of excisional goniotomy with the KDB and clarify the patient profiles best suited for this procedure.

How to cite this article

Dorairaj S, Radcliffe NM, Grover DS, et al. A Review of Excisional Goniotomy Performed with the Kahook Dual Blade for Glaucoma Management. J Curr Glaucoma Pract 2022;16(1):59–64.

Gonioscopy-assisted transluminal trabeculotomy is an effective surgical treatment for uveitic glaucoma

BACKGROUND

To assess the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in uveitic glaucoma (UG).

METHODS

A retrospective interventional case series in which 33 eyes of 32 patients with UG underwent GATT with or without concomitant cataract extraction and intraocular lens implantation (CE/IOL) at three Canadian treatment centres from October 2015 to 2020. The main outcome measure was surgical success defined as an intraocular pressure (IOP) ≤18 mm Hg and at least one of the following: IOP within one mm Hg of baseline on fewer glaucoma medications as compared with baseline or a 30% IOP reduction from baseline on the same or fewer medications. Secondary outcome measures were IOP, medication usage and surgical complications.

RESULTS

Mean patient age (mean±SD) was 49±16 years (range: 18-79) and 44% were female. GATT was performed as a standalone procedure in 52% of cases and the remainder were combined with CE/IOL. Surgical success was achieved in 71.8% (SE: 8.7%) of cases. Mean preoperative IOP (±SD) was 31.4±10.8 mm Hg on a median of 4 medications. 59% of patients were on oral carbonic anhydrase inhibitors (CAIs) prior to surgery. After 1 year, average IOP was 13.8 mm Hg on a median 1 medication, with 6% of patients being on oral CAIs. No sight threatening complications occurred during surgery or follow-up.

CONCLUSION

GATT is an effective surgical strategy in the management of UG. This microinvasive conjunctival-sparing procedure should be considered early in these patients.

Minimally Invasive Glaucoma Surgery: A Critical Appraisal of the Literature

Micro- or minimally invasive glaucoma surgeries (MIGS) have been the latest addition to the glaucoma surgical treatment paradigm. This term refers not to a single surgery, but rather to a group of distinct procedures and devices that aim to decrease intraocular pressure. Broadly, MIGS can be categorized into surgeries that increase the trabecular outflow [Trabectome, iStent (first and second generations), Hydrus microstent, Kahook Dual Blade and gonioscopy-assisted transluminal trabeculotomy], surgeries that increase suprachoroidal outflow (Cypass microstent and iStent Supra), and conjunctival bleb-forming procedures (Xen gel stent and InnFocus microshunt). Compared to traditional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves), MIGS are touted to have less severe complications and shorter surgical time. MIGS represent an evolving field, and the efficacy and complications of each procedure should be considered independently, giving more importance to high-quality and longer-term studies.

Microinvasive Glaucoma Surgery: An Evidence-Based Review

PURPOSE

Interest in micro-invasive glaucoma surgery (MIGS) has exploded over the last 8 years with an increase in MIGS procedures of at least 400% in the United States, according to Medicare data. MIGS is an umbrella term that can cover many different types of surgeries. This review focuses on peer-reviewed evidence for Trabectome^®, iStent inject^®, Kahook Dual Blade^®, XEN^® Gel Stent, and Hydrus^®.

METHODS

We present key recent studies evaluating the efficacy and safety of MIGS in various types of glaucoma patients with different stages of disease.

CONCLUSION

We conclude that MIGS is generally safe and efficacious, although only some MIGS have been studied through randomized clinical trials. When comparing and contrasting the different MIGS procedures, large prospective studies are not yet the norm. High-quality large prospective studies involving MIGS will be an important next step as ophthalmologists decide how to incorporate MIGS into their surgical armamentarium.

A review of additive manufacturing applications in ophthalmology

Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.

Performances of glaucoma operations with Kahook Dual Blade or iStent combined with phacoemulsification in Japanese open angle glaucoma patients

AIM

To compare surgical outcomes of phacoemulsification combined with glaucoma surgical techniques performed with either Kahook Dual Blade (KDB) or iStent for Japanese patients with either primary open angle glaucoma or exfoliation glaucoma.

METHODS

We retrospectively evaluated the surgical outcomes of 129 eyes of 84 Japanese patients with glaucoma who underwent KDB or 44 eyes of 34 patients who underwent phacoemulsification with iStent procedures combined with cataract surgery. The primary outcome was surgical success or failure [with surgical failure being indicated by <20% reduction from preoperative intraocular pressure (IOP) or IOP>18 mm Hg as criterion A; IOP>14 mm Hg as criterion B on two consecutive study visits; or reoperation requirement]. In addition, we assessed the number of postoperative glaucoma medications and the resulting complications.

RESULTS

The probability of success was significantly higher in the KDB group than in the iStent group for criterion A (60.2% vs 46.4%, P=0.019). In the KDB group, the mean preoperative IOP of 19.8±7.3 mm Hg decreased significantly to 13.0±3.1 mm Hg (P<0.01), and the mean number of glaucoma medications at 2.5±1.4 decreased significantly to 1.6±1.6 (P<0.01) 12mo postoperatively. In the iStent group, the mean preoperative IOP of 17.8±2.9 mm Hg significantly decreased to 14.3±2.3 mm Hg (P<0.01), and the mean number of glaucoma medications at 2.2±1.1 decreased significantly to 0.9±1.4 (P<0.01) 12mo postoperatively. The overall IOP reduction percentage was higher in the KDB group (26.2%) than in the iStent group (19.0%) 12mo postoperatively (P=0.03). Hyphema occurred significantly more frequently in the KDB group (16.3%) than in the iStent group (2.3%, P=0.017).

CONCLUSION

KDB and iStent procedures combined with cataract surgery both result in significant IOP and glaucoma medication reductions after the 12-month follow-up. The patients in the KDB group have a higher success rate for the target IOP of less than 18 mm Hg and a higher complication rate than those in the iStent group.

Comparison Of Surgical Outcomes Between Excisional Goniotomy Using The Kahook Dual Blade And iStent Trabecular Micro-Bypass Stent In Combination With Phacoemulsification

PURPOSE

To compare 6-month surgical outcomes of patients who underwent phacoemulsification (Phaco) combined with iStent implantation (iStent) versus excisional goniotomy using Kahook Dual Blade (KDB).

METHODS

Retrospective comparative case series of 58 iStent-Phaco eyes and 44 KDB-Phaco eyes operated upon by a single surgeon between 2016 and 2018. Preoperative, intraoperative, and postoperative intraocular pressure (IOP) and IOP-lowering medication data were collected. The primary outcome was the proportion of eyes using ≥1 fewer IOP-lowering medication at Month 6 while maintaining IOP ≤ 18 mmHg.

RESULTS

Baseline IOP was 17.2 (standard error 0.7) in the KDB-Phaco group using a mean of 1.9 (0.2) medications; at Month 6, mean IOP was 14.8 mmHg P=0.002) on 1.0 (0.2) medications (P<0.002). Baseline IOP was 16.7 (0.4) in the iStent-Phaco group using a mean of 1.4 (0.1) medications; at Month 6, mean IOP was 14.2 mmHg (P<0.002) on 1.4 (0.1) medications P=0.374). Changes in IOP and medications were not significantly different between groups (P>0.05). Significantly more KDB-Phaco eyes than iStent-Phaco eyes (43.2% vs 17.2%, P=0.004) were using ≥1 fewer medications while maintaining IOP ≤18 mmHg at Month 6. Adverse events were uncommon and similar in nature and frequency between groups with the exception that more KDB-Phaco eyes than iStent-Phaco eyes (8 [18.2%] versus 1 [1.7%]) experienced an IOP elevation presumed to be related to steroid use.

CONCLUSION

KDB-Phaco and iStent-Phaco provided comparable IOP and medication reductions. The proportion of eyes able to discontinue 1 or more medications while maintaining IOP ≤ 18 mmHg was significantly greater in eyes undergoing KDB-Phaco.