Circumferential Schlemm’s Canal Surgery in Adult and Pediatric Glaucoma

Phacoemulsification with gonioscopy-assisted transluminal trabeculotomy versus phacoemulsification alone in primary angle closure glaucoma: A randomized controlled study

PURPOSE

To assess the safety and efficacy of combining phacoemulsification with gonioscopy-assisted transluminal trabeculotomy (GATT) compared to phacoemulsification alone in the management of primary angle closure glaucoma (PACG).

METHODS

Prospective, institutional study in which eyes requiring surgery for PACG were randomized to undergo phacoemulsification followed by GATT (phaco-GATT group) or phacoemulsification alone. Success was defined as having a final IOP of 6-20 mmHg with no subsequent glaucoma surgery or vision-threatening complications.

RESULTS

Thirty-six eyes underwent phaco-GATT with 360° angle incision and 38 eyes underwent phacoemulsification alone. IOP and glaucoma medications were significantly lower in the phaco-GATT group at 1, 3, 6, 9 and 12 months. The success rate in the phaco-GATT group was 94.4% after 12.16 ± 2.03 months, with 75% of eyes being off medications compared to 86.8% after 12.47 ± 4.27 months in the phaco group, with 42.1% off medications. (p = 0.008). Hyphema and fibrinous anterior chamber reaction were the most common complications in the phaco-GATT group and resolved with conservative treatment or required YAG capsulotomy. Although this delayed visual rehabilitation in the phaco-GATT group, it did not affect the final visual outcome with no significant difference in the final best-corrected visual acuity between both groups (p = 0.25).

CONCLUSION

Combining phacoemulsification with GATT in PACG yielded more favourable outcomes in terms of IOP, glaucoma medications and surgical success. Although the postoperative hyphema and fibrinous reaction may delay visual rehabilitation, GATT further lowers the IOP by breaking residual peripheral anterior synechiae and removing the dysfunctional trabeculum circumferentially, while avoiding the risks inherent in more invasive filtering procedures.

Outcomes of 60-Degree Nasal Goniotomy for Open Angle Glaucoma

PRCIS

Sixty-degree nasal sectoral juxtacanalicular space goniotomy with the single-use Espaillat juxtacanalicular space slider device significantly reduced intraocular pressure and the number of required glaucoma hypotensive medications, with sustained reductions over 24 months.

PURPOSE

This study analyzed the safety and efficacy of the Espaillat juxtacanalicular space slider during minimally invasive 60-degree nasal sectoral goniotomy for mild-to-moderate open angle glaucoma (OAG).

PATIENTS AND METHODS

This prospective, observational case series performed at a private clinical practice and outpatient surgery center assessed the eyes of patients with mild-to-moderate OAG who underwent phacoemulsification cataract surgery with 60-degree nasal sectoral goniotomy using the Espaillat juxtacanalicular space slider. The same surgeon performed all procedures. Intraocular pressure, intraocular pressure-lowering drugs, and adverse effects were assessed over 24 months, and a regression analysis of intraocular pressure reduction was performed. Success was defined as (1) A reduction in the intraocular pressure of at least 20% for at least 12 months, compared with the baseline value, and (2) a decrease in the number of medications by at least one for at least 12 months.

RESULTS

Among 38 eyes, 27 (72%) had moderate glaucoma, and 11 (28%) had mild glaucoma. Postoperatively, intraocular pressure was decreased by 38% at 12 months (mean 13.7±1.7 mmHg), 35% at 18 months (mean 14.4±1.8 mmHg), and 31% at 24 months (mean 15.2±1.9 mmHg). In addition, the number of topical glaucoma medications used decreased from a mean of 1.6 to 0.4 ( P <0.001). The main adverse event was temporary focal corneal edema (29 patients; 76%).

CONCLUSIONS

Using the Espaillat juxtacanalicular space slider during invasive 60-degree nasal sectoral goniotomy for OAG yielded a significant and sustained reduction in intraocular pressure and reduced the need for glaucoma medications with minimal adverse events.

Gonioscopy-Assisted Transluminal Trabeculotomy following Failed Glaucoma Surgery in Primary Congenital Glaucoma: One-Year Results

Purpose

To evaluate the one-year outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in primary congenital glaucoma (PCG) with a history of prior glaucoma surgery.

Methods

A retrospective chart review was performed to identify all PCG patients ≤ 16 years who underwent GATT surgery at Cairo University Children's Hospital from January 2016 to March 2022. Pre- and postoperative intraocular pressure (IOP) and glaucoma medications were collected at 1, 3, 6, 9, 12, and last follow-up visits. Success was defined as IOP ≤ 21 mmHg without (complete) or with (qualified) glaucoma medications at the last follow-up.

Results

Seven eyes of 6 subjects were included in the study. The mean IOP was statistically significantly reduced from 25.7 ± 5.9 mmHg preoperatively to a mean IOP of 12 ± 1.5 mmHg (P = 0.001) at 12 months and 11.5 ± 1.2 mmHg (P = 0.001) at the last follow-up visit. Six eyes (85.7%) achieved complete success, and one eye (14.2%) achieved qualified success. No patients required further glaucoma procedures. No serious intra- or postoperative complications were identified.

Conclusions

Our early experience highlights that GATT can be performed as an alternative procedure before considering conjunctival or scleral glaucoma surgeries.

Controversies in Pediatric Angle Surgery and Secondary Surgical Treatment

Pediatric glaucoma is a constellation of challenging ophthalmic conditions that, left untreated, can result in irreversible vision loss. The mainstay of treatment for primary congenital glaucoma and select secondary glaucoma subtypes is angle surgery, either trabeculotomy or goniotomy. More recently, MIGS devices have been utilized to enhance the efficacy of these procedures. Despite the high success rates of these primary surgical options, refractory cases are challenging to manage. There is no consensus on the next step of treatment following primary angle surgery. Glaucoma drainage devices and trabeculectomies have been the traditional options, with laser treatment reserved for more severe cases. The benefits and disadvantages of each of these options are discussed.

Topical netarsudil 0.02% as adjunctive therapy in refractory pediatric glaucoma

PURPOSE

To evaluate the efficacy of topical netarsudil 0.02% as adjunctive therapy in children with refractory pediatric glaucoma.

METHODS

The medical records of patients ≤18 years diagnosed with pediatric glaucoma treated with topical netarsudil 0.02% from June 2019 to March 2022 were reviewed retrospectively. Data collected included age, sex, ethnicity, etiology of glaucoma, history of previous or subsequent glaucoma surgery, and intraocular pressure (IOP) before and after the addition of topical netarsudil.

RESULTS

A total of 21 eyes of 16 patients (11 males) were included. Five patients used topical netarsudil in both eyes. Eight patients were Hispanic. The mean number of glaucoma surgeries and medications before initiating topical netarsudil was 1.8 ± 1.2 and 3.7 ± 0.5, respectively. The mean age prior to starting topical netarsudil was 8.9 ± 4.1 years. The mean follow-up after initiating topical netarsudil was 11.3 ± 8.2 months. The IOP was significantly reduced from 26.3 ± 6.2 mm Hg before topical netarsudil to 19.6 ± 6.02 mm Hg at 1 month in 15 eyes (P < 0.01), 18.2 ± 6.9 mm Hg at 3-months in 18 eyes (P < 0.01), 18.3 ± 7.3 mm Hg at 6 months in 13 eyes (P = 0.01), 17.6 ± 5.07 mm Hg at 9 months in 14 eyes (P = 0.002), and 17.4 ± 3.1 mm Hg at 12 months in 13 eyes (P = 0.002). Nine eyes (43%) underwent additional glaucoma surgery due to long-term failure of topical netarsudil to reduce IOP despite an initial reduction, and one eye had persistent IOP elevation ≥21 mm Hg despite the addition of topical netarsudil.

CONCLUSIONS

In our small cohort of patients with refractory pediatric glaucoma, the addition of topical netarsudil reduced IOP, potentially delaying the need for surgery.

Systematic Review of MIGS and Non-Penetrating Glaucoma Procedures for Uveitic Glaucoma

Minimally invasive glaucoma surgeries (MIGS) and non-penetrating glaucoma procedures have changed the surgical management of glaucoma in recent years and are being explored in the management of uveitic glaucoma. Deep sclerectomy, Xen45 gel stent, gonioscopy-assisted transluminal trabeculotomy (GATT), trabectome, and canaloplasty are described in the literature as alternative surgeries that may work for uveitic glaucoma. While most of the published studies are retrospective case series, the results suggest success even in refractory cases and with less inflammation than more traditional surgeries.

Minimally Invasive Glaucoma Surgery in Primary Angle-Closure Glaucoma

Primary angle-closure glaucoma (PACG) is responsible for half of the glaucoma-related blindness worldwide. Cataract surgery with or without trabeculectomy has been considered to be the first-line treatment in eyes with medically uncontrolled PACG. While minimally invasive glaucoma surgery has become an important surgical approach for primary open-angle glaucoma, its indications and benefits in PACG are less clear. This review summarizes the efficacy and safety profile of minimally invasive glaucoma surgery in PACG to unfold new insights into the surgical management of PACG.

Clinical application of the CO2 laser in Ab externo Schlemm's canal surgery

Purpose

This study aimed to investigate the clinical application of laser as a knife in Ab externo Schlemm's canal (SC) surgery and compare the efficacy and safety of the CO₂ laser with the conventional procedure using a surgical knife.

Methods

Patients who underwent either canaloplasty or trabeculotomy with CO₂ laser system which was used to locate and ablate the outer wall of SC at the time interval between May 2020 and May 2021 were identified, their medical files were reviewed, and their results were compared with conventional surgery group who underwent canaloplasty or trabeculotomy with conventional surgical knife at the same time period. The following datas were conducted and compared: age, sex, intraocular pressure (IOP), number of drugs, best-corrected visual acuity (BCVA), mean deviation and pattern standard deviation of visual field examination, SC opening related complications.

Results

A total of 49 patients (49 eyes) were included in this study, including 23 in the Laser surgery group and 26 in the conventional surgery group. Time for SC opening was 49.33 ± 25.23 s and 116.50 ± 31.79 s for laser surgery group and conventional surgery group, respectively. This difference between the two groups was statistically significant (P < 0.01). Hemorrhage occurred in five eyes during ablation for the laser surgery group and in 24 eyes for the conventional surgery group. In addition, anterior chamber penetration occurred in two cases for the laser surgery group and in six cases for the conventional surgery group. The success rate of identifying and opening outer wall of SC was 91.30% (21 eyes) for the laser surgery group and 76.92% (20 eyes) for the conventional surgery group. The difference between preoperative and postoperative intraocular pressure for each group was statistically significant (P < 0.01), and there were no statistically significant differences across the two groups in terms of postoperative IOP (P = 0.238) and BCVA (P = 0.389).

Conclusion

Compared with the conventional procedure using a surgical knife, CO₂ laser-assisted ablation of the outer wall of SC was less time-consuming and less technically challenging. CO₂ laser-assisted ablation also resulted in fewer complications. Furthermore, it had a shorter learning curve and a higher success rate of identifying and opening SC.

Gonioscopy-Assisted Transluminal Trabeculotomy; A Review

AIM

To review the recent evidence in the literature regarding the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in the management of pediatric and adult glaucoma.

METHODS

A literature search was performed in the electronic databases of PubMed, Google Scholar, Embase the Register of Controlled Trials, and Ovid Medline for studies evaluating the safety and outcomes of GATT in glaucoma.

RESULTS

GATT is a novel minimally invasive glaucoma surgery that allows the incision of the inner wall of Schlemm's canal increasing aqueous drainage through the physiologic outflow pathway with subsequent intraocular pressure reduction in different types if of glaucoma.

CONCLUSION

GATT demonstrated favorable results in a wide range of both primary and secondary open-angle and angle-closure glaucoma.

Minimally invasive glaucoma surgery in childhood glaucoma

PURPOSE OF REVIEW

Minimally invasive glaucoma surgery (MIGS) has been shown to be safe and effective in treatment of mild to moderate glaucoma in adults, but reports in childhood glaucoma are limited. We review the available data concerning MIGS and discuss its potential role in childhood glaucoma management.

RECENT FINDINGS

Ab interno counterparts to circumferential ab externo trabeculotomy such as gonioscopy-assisted transluminal trabeculotomy (GATT) and Trab360 show promise in treatment of primary glaucomas as reported in a few retrospective case series. Kahook Dual Blade (KDB) and Trabectome have demonstrated mixed results in few published case reports in children. Small case series and reports suggest that the Xen gel stent can be a safer alternative to traditional filtration surgery, though data on long-term implant and bleb stability are unavailable. Newer devices are being investigated and early results are encouraging.

SUMMARY

GATT and Trab360 seem to be safe, effective methods of achieving circumferential trabeculotomy in childhood glaucoma. KDB, Trabectome, and Xen gel stent have shown some success in selected cases with short-term follow-up. Surgeons must determine the risks and benefits of MIGS over more established methods of intraocular pressure reduction for each individual child. Further research is needed to validate initial findings regarding MIGS in childhood glaucoma.

Cost-analysis of Surgical Intraocular Pressure Management in Glaucoma

PRCIS

The multiplicity of treatment options for lowering intraocular pressure (IOP) is both a blessing and a challenge. Some attention to cost-analysis might assist in choosing an optimal therapy, especially in a cost-constrained, international setting.

PURPOSE

The aim of this study was to quantify and to analyze the relative cost of various glaucoma surgical procedures and selective laser trabeculoplasty surgery per mm Hg IOP reduction ($/mm Hg) since standard cost-utility methods are not well suited to the study of glaucoma which characteristically only claims visual acuity in its end stages.

METHODS

Published glaucoma treatment studies were reviewed to quantitate the reduction of mean IOP and glaucoma medications for a given treatment modality. A US perspective was adopted, using Medicare allowable costs were used to calculate a newly introduced parameter-cost per mm Hg IOP reduction-at 1 year postoperatively.

RESULTS

The cost per mm Hg IOP reduction after 1 year of treatment ranged from $190/mm Hg for trabeculectomy to $1376/mm Hg for iStent. For reference, the cost of selective later trabeculoplasty surgery was $121/mm Hg. After the first year, cost/mm Hg ranged from $12 to $61/mm Hg.

CONCLUSIONS

Conventional glaucoma surgeries and selective laser trabeculoplasty surgery were the most cost-efficient surgical methods to lower IOP compared with the various minimally invasive glaucoma surgeries options. They may be more appropriate management when cost is an important issue.

Microcatheter-Assisted Trabeculotomy Combined With Deep Sclerectomy and Trabeculectomy in Young to Middle-Aged Adults With Advanced Primary Open-Angle Glaucoma: 1-Year Result

Objective: We aimed to evaluate the safety and clinical efficacy of ab externo microcatheter-assisted trabeculotomy combined with deep sclerectomy and trabeculectomy (MATT-DS-Trab) in the surgical management of advanced primary open-angle glaucoma (POAG).

Methods: According to the inclusion criteria, we retrospectively collected and analyzed 37 POAG cases in advanced stage who received MATT-DS-Trab. The intraocular pressure (IOP), best corrected visual acuity (BCVA), use of anti-glaucoma drugs, shape of the filtering bleb, size of the scleral lake, complications, and the surgical success rate were recorded.

Results: The mean IOP was 37.50 ± 8.11 mmHg before the operation, while it depleted to 10.08 ± 2.01 and 11.43 ± 2.07 mmHg at 1 week and 12 months after the operation, respectively (both P < 0.001 compared to preoperative IOP). From none to two kinds of anti-glaucoma drugs were used 12 months after surgery on the patients, which were significantly reduced compared with that preoperatively (P < 0.001). An L-type filtering bleb was the main form at all time points after the operation. At 12 months following surgery, an F-type filtering bleb accounted for 5.41% and no E-type filtering bleb was recorded. The length and height of the scleral lake shrunk with time, but there was no statistical significance (P > 0.05). Also, there was no correlation between the size of the scleral pool and the IOP (P > 0.05). At 12 months after the operation, the complete success rates were 94.59, 83.78, and 72.97% according to standards A (≤18 mmHg), B (≤15 mmHg), and C (≤12 mmHg), respectively. Intraoperative complications were mainly anterior chamber hemorrhage, and no complications related to the filtration bleb were observed after the operation.

Conclusion: Based on multichannel mechanisms, MATT-DS-Trab is able to effectively reduce IOP in advanced POAG patients, with few serious complications and a high success rate.

Early Experience With Ahmed Clear Path Glaucoma Drainage Device in Childhood Glaucoma

PURPOSE

The aim was to evaluate the short-term outcomes of Ahmed clear path (ACP) valveless glaucoma drainage device in childhood glaucoma.

METHODS

Retrospective chart review of all patients 16 years or below with childhood glaucoma who had ACP implantation at Boston Children's Hospital from December 2019 to June 2020 with at least 6 months follow-up period.

RESULTS

The study included 7 eyes of 5 patients implanted by a single surgeon. The median follow-up was 12 months. The mean intraocular pressure (IOP) was reduced from 36±3.5 mm Hg on a mean of 2.7±0.6 glaucoma medications preoperatively to a mean IOP of 12.4±2.8 mm Hg (P<0.001) on a mean of 0.7±0.8 medications postoperatively at final follow-up (P=0.0009). Complete success was achieved in 4 eyes while qualified success was achieved in 3 eyes.

CONCLUSION

The ACP glaucoma drainage device provided good short-term IOP control and technical advantages for implantation for pediatric eyes were observed.

Kahook Dual Blade Ab-interno Trabeculectomy Compared With Conventional Goniotomy in the Treatment of Primary Congenital Glaucoma: 1-Year Results

INTRODUCTION

Kahook dual blade (KDB) removes a strip of the trabecular meshwork from the angle, which may make it superior to simple goniotomy in treating the angle anomaly in primary congenital glaucoma (PCG). This prospective study compares KDB ab-interno trabeculectomy to conventional goniotomy in PCG.

METHODS

Forty-two eyes of 29 patients with PCG underwent ab-interno trabeculectomy using a KDB or conventional goniotomy using a 25-G irrigating needle, targeting 100 to 120 degrees of the nasal iridocorneal angle. Patients were seen at 1, 3, 6, and 12 months postoperatively. Success was defined as intraocular pressure (IOP) ≤21 mm Hg at 1-year follow-up visit, with no evidence of glaucoma progression.

RESULTS

The KDB group included 21 eyes of patients with a median age of 6 months (interquartile range: 4 to 8.5 mo) and the goniotomy group included 21 eyes of patients with a median age of 5 months (interquartile range: 3 to 9.5 mo). There was a significant reduction in IOP in both groups at all follow-up visits. The reduction in the number of glaucoma medications was significant at 1, 3, and 6 months postoperatively in the KDB group, and at 1 month in the goniotomy group. There was no significant difference in IOP or glaucoma medications between both groups at any follow-up visit. Success was achieved in 12 eyes (57.1%) in each group, with no eyes developing any serious complications.

CONCLUSION

One-year results show that KDB ab-interno trabeculectomy is at least as effective as goniotomy in the treatment of PCG. Eyes with bilateral glaucoma had a tendency to fail both procedures.

One-year results of two-site trabeculotomy in paediatric glaucoma following cataract surgery

PURPOSE

The management of glaucoma following cataract surgery (GFCS) in children is challenging. This study looks at the results of two-site trabeculotomy in paediatric aphakic/pseudophakic glaucoma, 1-year post operatively.

METHODS

This prospective, institutional study was performed on 33 eyes with GFCS in patients aged ≤14 years. Patients underwent two-site trabeculotomy using the rigid-probe trabeculotome, through a superonasal and an inferotemporal scleral flap. Intraocular pressure (IOP), medications, complications and success rates at 1 year were reported. Success was defined as IOP < 23 mmHg or 30% IOP reduction, on the same or fewer number of medications at 1 year, without the need for another glaucoma procedure.

RESULTS

Trabeculotomy was performed on average 3.5 years after the cataract surgery. Patients were aged 5.73 ± 1.79 years. We excluded four eyes in which >180° incision could not be achieved. A 360° incision was achieved in 14 eyes (48%). There was a significant reduction in IOP and medications at 1, 3, 6 and 12 months (p < 0.001). At 1 year, mean IOP reduction was 48.2 ± 31.5%. Success was achieved in 26 eyes (89.6%), of which 15 were controlled without medications. There was no significant difference in IOP, medications or success between aphakic and pseudophakic eyes nor between eyes that had 360° trabeculotomy and eyes that had a 180-270° incision. Three eyes (10.3%) required another glaucoma procedure. One eye required core vitrectomy for vitreous haemorrhage.

CONCLUSIONS

Two-site trabeculotomy can be used as an effective and safe first-line procedure in paediatric GFCS eyes that do not have extensive peripheral anterior synechiae.

Collector Channels: Role and Evaluation in Schlemm's Canal Surgery

OBJECTIVES

1) To elucidate the role of collector channels in the aqueous humor outflow pathway 2) To suggest anatomic and functional methods of imaging collector channels in-vitro and in-vivo and 3) To discuss the role of such imaging modalities in the surgical management of glaucoma.

METHODS

A thorough literature search was conducted on databases for studies published in English regarding the available methods to determine the role of collecting channels in normal and glaucomatous patients and to assess their patency.

RESULTS

Intraocular pressure (IOP) exists as a balance between aqueous humor production and aqueous humor outflow. Collector channels are an essential anatomical constituent of the distal portion of the conventional aqueous humor outflow pathway. There are different surgical options for glaucoma management and with the recent advances in Schlemm's canal-based surgeries, collector channel's patency became a key factor in determining the optimum management for the glaucomatous eye. The advent of anatomic imaging methods has improved the ability to visualize collector channel morphology in-vitro, including swept-source optical coherence tomography (SS-OCT), spectral domain optical coherence tomography (SD-OCT), micro-computed tomography (micro CT), new immunohistochemistry techniques and scanning electron microscopy. The recent advent of real-time assessment of collector channel patency (including evaluation of episcleral venous outflow, observation of episcleral venous fluid wave, and tracer studies utilizing fluorescein, indocyanine green, and trypan blue) has been validated by the aforementioned anatomic imaging modalities.

CONCLUSIONS

New modalities of in-vitro and in-vivo studies of collector channels provide promise to aid in the assessment of collector channel patency and individualization of surgical management for glaucoma patients.

Case Series of Brittle Cornea Syndrome

Purpose

This case series demonstrate diagnostic features, treatment options, and challenges for Brittle Cornea Syndrome. Observations. Three cases presented with bluish sclera and extremely thin cornea. Genetic workup was performed and confirmed the diagnosis of Brittle Cornea Syndrome, a rare autosomal recessive disorder characterized by corneal thinning and blue sclera. Case 1 was a 4-year-old boy who developed cataract and glaucoma after undergoing right tectonic penetrating keratoplasty (PK) secondary to a spontaneous corneal rupture. Glaucoma was controlled medically. Later, the kid underwent right transcorneal lensectomy and vitrectomy with synechiolysis. After 6 weeks, he sustained graft dehiscence that was repaired using onlay patch graft. Case 2 was a 7-year-old boy who underwent PK in the right eye, then a pericardial patch graft in the left eye following spontaneous corneal rupture. Glaucoma in both eyes was controlled medically. Case 3 was the 2-year-old sister of the 2^nd case. She had a pachymetry of 238 μm OD and 254 μm OD and 254 

Conclusions

Long-term follow-up of children diagnosed with Brittle Cornea Syndrome is paramount to minimize the morbidity of corneal rupture and late-onset extraocular conditions.