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.

Glaucoma Drainage Device Surgery Outcomes in Children With Uveitic Glaucoma.

PURPOSE: To evaluate outcomes of glaucoma drainage device (GDD) implantation children with uveitic glaucoma. DESIGN: Retrospective interventional case series. METHODS: Success was defined as intraocular pressure (IOP) ≥5 and ≤21 mm Hg. Failure was defined at final follow-up when the IOP was outside the success criterion, and visual function was no perception of light or if further glaucoma surgery (excluding removal of intraluminal stent suture or needling) was required. RESULTS: Fifty eyes of 36 children with uveitic glaucoma underwent GDD implantation. Mean age at surgery was 10.1±3.1 years (range 5-17) with a mean follow-up of 113±61 months (range 8-228). Mean cumulative probabilities of success (95% CI) were 0.98 (0.86-1.00) at 1 year, 0.87 (0.73-0.94) at 5 years, and 0.59 (0.32-0.78) at 15 years. Fourteen tubes were classified as failed, with 12 due to uncontrolled IOP (11 eyes required a second GDD); 1 eye, removal of the tube due to plate exposure; and 1 eye, lost light perception. Postoperative complications occurred in 36% of patients and included hypotony (22%), tube exposure (6%), tube obstruction (4%), corneal decompensation (2%), and cystoid macular edema (2%). Visual acuity remained stable (preoperation 0.35±0.42 vs postoperation 0.45±0.67, P = .49). IOP was significantly reduced from 31.4±7.5 mm Hg to 14.4±5.1 mm Hg (P < .0001) as were the number of glaucoma medications 3.5±1.0 vs 1.1±1.3 (P < .0001). CONCLUSIONS: Refractory pediatric uveitic glaucoma can be treated successfully by GDD implantation. Further interventions to manage consequences of glaucoma or the underlying disease are common, and visual function is maintained in the majority of cases.

Childhood glaucoma profile in a tertiary centre in Egypt according to the childhood glaucoma research network classification.

PURPOSE: To describe the prevalence and clinical characteristics of a large cohort of childhood glaucoma patients that presented to a tertiary Egyptian children's hospital using the childhood glaucoma research network (CGRN) classification. METHODS: A retrospective review of the medical records of all patients ≤ 14 years with a diagnosis of childhood glaucoma or glaucoma suspects who presented to Children's Hospital between January 2014 to December 2019 was conducted. Data collected included age at the time of diagnosis, gender, laterality, prenatal history, parental history, including consanguinity, intraocular pressure, horizontal corneal diameter, and cup-to-disc ratio. RESULTS: A total of 1113 eyes of 652 patients with diagnoses of either childhood glaucoma or glaucoma suspects were included in the study. Six hundred and sixteen patients (94%) were born full-term. A history of positive parental consanguinity was identified in 334 patients (51.2%). Almost 60% of patients were males. Primary congenital glaucoma (PCG) was the most prevalent diagnosis (68.2%), followed by glaucoma suspects (10.4%) and glaucoma following cataract surgery (GFCS) (8.4%). Juvenile open-angle glaucoma was the least prevalent category (0.3%). Other categories including glaucoma associated with non-acquired systemic disease, glaucoma associated with non-acquired ocular disease, and glaucoma associated with acquired conditions represented 5.8%, 4.7%, and 1.9%, respectively. CONCLUSIONS: PCG is the most common form of glaucoma in Egypt. More than half of the pediatric glaucoma patients had a positive history of parents' consanguinity.

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.

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.

Role of Matrix Metalloproteinase 9 in Ocular Surface Disorders.

OBJECTIVES: (1) To explore the role and significance of Matrix Metalloproteinase 9 (MMP-9), a proteolytic enzyme, in various ocular surface diseases of inflammatory, infectious, and traumatic etiology (2), to further elucidate the molecular mechanisms responsible for its overexpression in ocular surface disease states, and (3) to discuss possible targets of therapeutic intervention. METHODS: A literature review was conducted of primary sources from 1995 onward using search results populated from the US National Library of Medicine search database. RESULTS: MMP-9 overexpression has been found in in vitro and in vivo models of dry eye disease (DED), corneal ulceration, microbial keratitis, corneal neovascularization, ultraviolet light-induced radiation, and a host of additional surface pathologies. MMP-9 is involved in an intricate signal transduction cascade that includes induction by many proinflammatory molecules including interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-a), nuclear factor kappa light chain enhancer of activated B cells (NF-kB), platelet-activating factor, activator protein 1 (AP-1), and transforming growth factor beta (TGF-B). MMP-9 expression is blunted by a diverse array of molecular factors, such as tissue inhibitors of metalloproteinases, cyclosporine A (CyA), PES_103, epigalloccatechin-3-gallate (EGCG), N-acetylcysteine (NaC), ascorbate, tetracyclines, and corticosteroids. Inhibition of MMP-9 frequently led to improvement of ocular surface disease. CONCLUSIONS: Novel insights into the mechanistic action of MMP-9 provide potential for new therapeutic modulations of ocular surface diseases mediated by its overexpression.

Circumferential Schlemm's Canal Surgery in Adult and Pediatric Glaucoma.

Purpose: Although trabeculectomy, and to a less extent glaucoma drainage devices are currently the gold standard in glaucoma surgery, there is a rising interest in addressing the more physiological pathway of aqueous outflow through surgeries that target Schlemm's canal (SC). These surgeries have the advantage of a lower risk of hypotony and bleb-related complications commonly associated with conventional glaucoma surgery.In this article we review new developments and the different techniques of circumferential angle surgery in adult and pediatric glaucoma, as well as procedures which target the canal circumferentially without incising it, such as canaloplasty and Visco360.Methods: A comprehensive literature search of various electronic databases was performed.Results: Angle surgery, namely goniotomy and trabeculotomy, have been well established as standard procedures in pediatric glaucoma, yet their results in the management of adult glaucoma have not been as promising. In recent years, ab-interno trabeculectomy using Trabectome and Kahook dual blade have yielded variable results in adult glaucoma. As growing evidence suggests that bigger extent incisions into SC result in increased lowering of intraocular pressure than conventional 120 to 180-degree incisions, several procedures have been developed to create a circumferential incision into SC. Circumferential SC incision using sutures, microcatheters, TRAB360 or the rigid probe trabeculotome, through an ab-interno or ab-externo approach, have yielded promising results in both adult and pediatric glaucoma by reducing the resistance to aqueous outflow through the inner wall of SC over 360 degrees of the angle.Conclusions: Various techniques of circumferential Schlemm's canal surgery is effective in management of different adult and pediatric glaucomas. Further long-term comparative studies would be useful in evaluating safety and efficacy of these procedures.

Microcatheter-assisted Trabeculotomy Versus 2-site Trabeculotomy With the Rigid Probe Trabeculotome in Primary Congenital Glaucoma.

PURPOSE: The purpose of this study was to compare the outcomes of microcatheter-assisted trabeculotomy to circumferential trabeculotomy using the rigid probe trabeculotome in primary congenital glaucoma. METHODS: This retrospective study was performed in an institutional setting. The medical records of primary congenital glaucoma patients who underwent circumferential trabeculotomy (≥270 degrees incised) using Glaucolight-illuminated microcatheter or a rigid probe trabeculotome were reviewed. The primary outcomes were the percent reduction of intraocular pressure (IOP) and success rates. Complete success was defined as achieving an IOP<18 mm Hg without medications. Secondary outcomes were the postoperative IOP and glaucoma medications. RESULTS: The study included 92 eyes of 92 patients. Of these, 33 eyes of 33 patients aged 6.4±8.7 months underwent microcatheter-assisted trabeculotomy creating a 336±34-degree incision, with 19 eyes (58%) having a complete 360-degree incision. The other 59 eyes of 59 patients aged 8.2±13.1 months underwent 2-site trabeculotomy, using a rigid probe trabeculotome through a combined superonasal and inferotemporal approach, creating a 338±29-degree incision, with 33 eyes (56%) having a complete incision. After a follow-up of 21.2±8.9 months, there was a 42%±25% IOP reduction and a 73% rate of complete success in the microcatheter group, compared with 40%±22% IOP reduction and an 80% success rate in the rigid probe group (P=0.7 and 0.3, respectively). There was no significant difference in survival time in both groups (P=0.6). CONCLUSION: Circumferential trabeculotomy using either the illuminated microcatheter or rigid probe trabeculotome yielded comparable results; however, the added cost of the microcatheter should be considered.

Excision of Tenon Capsule in Pediatric Trabeculectomy: A Controlled Study.

PURPOSE: To compare the results of trabeculectomy alone and combined with partial tenonectomy in pediatric glaucoma patients. METHODS: This was a prospective, controlled, cohort study that included 64 eyes of 46 children younger than 12 years with uncontrolled glaucoma, who underwent trabeculectomy with mitomycin C in an institutional setting. Patients were randomized to undergo a trabeculectomy either with (group A) or without (group B) tenonectomy. Children were followed up prospectively for 24 months. Kaplan-Meier survival analysis and mean survival times with 95% confidence intervals (CIs) were calculated. Postoperative results were compared at 3, 6, 12, and 24 months of follow-up. The main outcome measures were: intraocular pressure (IOP), surgical success, postoperative interventions, and complications in both groups. RESULTS: Mean postoperative IOP was lower in group A at all postoperative visits (19.2 mm Hg in group A vs. 22.1 mm Hg in group B at 24 mo, P=0.05). There was a tendency toward greater use of glaucoma medications in group B (P<0.001). Cumulative probability of survival at 24 months was 70% (95% CI, 48%-86%) for group A, and 45% (95% CI, 28%-63%) for group B (P=0.09). Mean survival time was significantly longer (P=0.04) in group A (16.6 mo) than in group B (11.6 mo). Encapsulation occurred more frequently (P=0.03) in group B (25%) than in group A (3%). CONCLUSIONS: Excision of the Tenon capsule could help achieve better IOP control in pediatric glaucoma surgery.