Management of experimental trabeculectomy filtering blebs via crosslinking of the scleral flap inhibited vascularization

PURPOSE

The aim of this study was to evaluate whether UVA-light-activated riboflavin-induced collagen crosslinking (UVA-CXL) can maintain the function of filtering blebs after trabeculectomy (TRAB) in rabbits.

METHODS

Thirty-six healthy rabbits were randomized to one of the following groups with 12 rabbits in each group: Trabeculectomy group (TRAB group), trabeculectomy combined with CXL group (CXL group), and trabeculectomy combined with MMC group (MMC group). Six rabbits of each group were performed with intraocular pressure (IOP), optical coherence tomography (OCT), and OCT angiography (OCTA). Bleb structure was observed via hematoxylin & eosin (H&E) and Masson staining. Immunohistochemistry, proteomic study, western blot, and tensile test were performed between CXL group and the control. In vitro, cell viability was evaluated by CCK-8 and Calcein/PI staining. TRPV4 and VEGF-a expression levels were measured by Q-PCR. Ca2+ concentration was observed with Fluo-4 AM.

RESULTS

The IOP and bleb median survival day were significantly modified in CXL (5.92 ± 0.32 mmHg and 15.5 days) than TRAB group (7.50 ± 0.43 mmHg and 9 days). The bleb area and height increased. CXL inhibited vascularization, and vascularization peaked at postoperative day (POD) 14 and then decreased gradually. In proteomic analyses, Z disc, actin filament binding, and sarcomere organization were significantly enriched. CXL inhibited scleral stress‒strain in tensile tests. Compared with TRAB group, TRPV4 expression was significantly increased, but VEGF-a and TGF-β1 levels were reduced in the CXL group in western blot. Meanwhile, TRPV4 expression colocalized with CD31. In vitro, CXL inhibited HUVECs cell viability. After CXL, expression level of TRPV4 was increased and calcium influx was activated, but VEGF-a was decreased in HUVECs.

CONCLUSIONS

This study demonstrates that intraoperative UV-RF CXL can significantly improve the success rate of TRAB via inhibiting filtering bleb vascularization. CXL increased sclera stiffness, in turn, induced TRPV4 activation, thus contributing to vascular endothelial cells suppression.

Comparing Outcomes of Trabeculotomy with Mitomycin C to 45-μm Gelatin Stent Placed Ab Externo with Open Conjunctiva

PURPOSE

To compare trabeculectomy with mitomycin C (trab-MMC) and XEN45 Gel Stent placed ab externo with open conjunctiva (XGS AEO) with or without cataract surgery in patients with glaucoma.

DESIGN

Nonrandomized, retrospective, comparative study.

SUBJECTS

A total of 204 eyes from 204 glaucoma patients who received XGS AEO or underwent trab-MMC with or without cataract surgery between July 2018 and August 2021 at Massachusetts Eye and Ear.

METHODS

Visits from 204 patient charts were reviewed after either trab-MMC or XGS AEO from 2018 to 2021 from a level 3 triage center.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP), medication burden, Kaplan-Meier success rates, 5-fluorouracil impact, and complications.

RESULTS

One hundred fifty-seven patients underwent trab-MMC and 47 underwent XGS AEO. Groups had similar baseline intraocular pressure (IOP) and medications (meds). Intraocular pressure and meds decreased similarly at 1.5 years (11.2 mmHg vs. 7.4 mmHg, P = 0.62; 2.9 vs. 2.8 meds, P = 0.92, respectively for trab-MMC and XGS AEO). Success was defined as IOP reduction ≥ 20% with 5 mmHg ≤ IOP ≤ 18 mmHg for 2 consecutive visits. Complete success (CS) did not allow meds; qualified success (QS) allowed for ≤ baseline meds. When IOP fluctuations in the first 60 days were not counted as failures, CS was 43% for trab-MMC, about 8.5% higher than for XGS AEO (P < 0.01). Qualified success was similar between the groups (65%-67%). Procedure time was shorter for XGS AEO than trab-MMC (44 vs. 63 minutes, P < 0.01).

CONCLUSIONS

XEN45 Gel Stent AEO may provide similar benefits to trab-MMC, especially for patients who tolerate some meds, with shorter procedure times.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Long-term Remodeling Response in the Lamina Cribrosa Years after Intraocular Pressure Lowering by Suturelysis after Trabeculectomy

OBJECTIVE

To measure the remodeling of the lamina cribrosa (LC) years after intraocular pressure (IOP) lowering by suturelysis.

DESIGN

Cohort study.

PARTICIPANTS

Glaucoma patients were imaged 20 minutes after laser suturelysis after trabeculectomy surgery and at their follow-up appointment 1 to 4 years later (16 image pairs; 15 persons).

INTERVENTION

Noninvasive OCT imaging of the eye.

MAIN OUTCOME MEASURES

Deformation calculated by correlating OCT scans of the LC immediately after IOP lowering by suturelysis and those acquired years later (defined as remodeling strain).

RESULTS

The LC anterior border moved 60.9 ± 54.6 μm into the eye (P = 0.0007), and the LC exhibited regions of large local stretch in the anterior-posterior direction on long-term, maintained IOP lowering, resulting in a mean anterior-posterior remodeling strain of 14.0% ± 21.3% (P = 0.02). This strain and the LC border movement was 14 times and 124 times larger, respectively, than the direct response to IOP lowering by suturelysis. A larger anterior LC border movement was associated with greater mean anterior-posterior remodeling strain (P = 0.004). A thinner retinal nerve fiber layer at suturelysis was also associated with greater mean anterior-posterior remodeling strain at follow-up (P = 0.05). Worsening visual field indexes during follow-up were associated with a greater mean circumferential remodeling strain (P = 0.02), due to regions of large local circumferential stretch of the LC. Eyes with a more compliant LC torsional shear strain response at lysis were associated with worse mean deviation at follow-up (P = 0.03).

CONCLUSIONS

Strains and LC border position changes measured years after IOP lowering are far larger than the immediate response to IOP lowering and indicate dramatic remodeling of the LC anatomical structure caused by IOP lowering and glaucoma progression. The remodeling strains indicate substantial local stretch in the anterior-posterior direction and are associated with movement of the LC anterior border into the eye. Eyes with greater direct strain response to IOP lowering, greater glaucoma damage at suturelysis, and greater worsening of visual field at follow-up experienced greater remodeling.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03267849.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Intrascleral intraocular lens fixation with ab interno trabeculotomy in patients with exfoliation glaucoma with lens subluxation

PURPOSE

To evaluate the surgical outcomes of intrascleral intraocular lens (IOL) fixation using ab interno trabeculotomy (LOT) in patients with exfoliation glaucoma with lens subluxation.

STUDY DESIGN

Retrospective case series.

METHODS

Twenty eyes of 18 patients with exfoliation glaucoma and lens or IOL subluxations were included. Three success criteria were based on postoperative intraocular pressure (IOP) (A, ≤15 mmHg; B, ≤18 mmHg; C, ≤21 mmHg). The IOP, number of glaucoma medications, and visual acuity were compared before and after surgery. Success probability was analyzed using Kaplan-Meier survival curves. Cox proportional hazards' regression models were used to examine prognostic factors for surgical failure.

RESULTS

The mean follow-up period was 23.4 ± 7.8 months. The mean IOP significantly decreased from 23.2 ± 6.8 mmHg preoperatively to 14.0 ± 4.4 mmHg at 1 year postoperative (P<0.001). Postoperative hyphema and vitreous hemorrhage were observed in seven and 15 eyes, respectively, and washout in the anterior chamber or vitreous cavity was performed in four eyes. Postoperative IOP spikes and hypotony were observed in four eyes each. Glaucoma reoperation was performed in two eyes. The success rates at 12 months were 65%, 85%, and 90% using criteria A, B, and C, respectively. The IOP at 1 month after surgery was a significant prognostic factor for surgical failure according to criterion A (hazard ratio: 1.08; P=0.034).

CONCLUSION

Intrascleral IOL fixation combined with microhook LOT is a promising option in cases of exfoliation glaucoma with subluxated lens/IOL; however, the high rate of postoperative hyphema and vitreous hemorrhage should be noted.

Comparison between MIGS with trabeculectomy in the management of open-angle glaucoma with cataract: A systematic review

Age is an important risk factor for both glaucoma and cataract. As global life expectancy continues to rise, the prevalence of concomitant open-angle glaucoma (OAG) and cataracts is increasing. Currently, there is a lack of definitive consensus on the optimal management approach for such individuals. Conventionally, trabeculectomy (Trab) in combination with phacoemulsification is the preferred method. Recent developments in microinvasive glaucoma surgery (MIGS), which offer similar results with fewer complications, provide a new possible approach to this condition. This study aimed to assess the current knowledge of combination surgery in patients with cataract and OAG to provide a comprehensive understanding and help its implementation in clinical settings. A comprehensive systematic search was conducted in May 2021 on five databases (MEDLINE, Embase, SCOPUS, Proquest, EBSCO, and Cochrane Library). The results were filtered for English and human studies but not publication year. All studies published up to May 2021 were reviewed. Newcastle-Ottawa Scale and PEDro scale were used to screen studies for risk of bias where appropriate. Four studies satisfied the inclusion criteria and were subsequently added in this review. Study designs consisted of one RCT and three descriptive studies. Appropriate assessment tools were used; these studies demonstrated moderate to good quality. Postoperative mean IOP, IOP reduction, and qualified success rates were comparable in the Phaco-MIGS (Phaco-endoscopic cyclophotocoagulation (ECP), Phaco-ab interno trabeculectomy (AIT)) and Phaco-Trab group. Severe complication was reported only in the latter. Phaco-MIGS (in particular, trabectome) shows excellent promise as an option for individuals with OAG and concomitant cataract; further research through RCT is required to validate these findings.

Clinical Characteristics and Surgical Outcomes of Turkish Patients With Pediatric Glaucoma Who Underwent Glaucoma Surgery in a University Hospital

PURPOSE

To describe the clinical characteristics and outcomes of a pediatric cohort surgically treated for primary or secondary pediatric glaucoma (PPG/SPG).

METHODS

A retrospective chart review was conducted of all patients with pediatric glaucoma who had surgery between 2013 and 2021. Relevant demographic and clinical data were cumulated and analyzed.

RESULTS

Forty-two eyes of 29 patients (18 girls and 11 boys) were included: 22 (52.4%) primary congenital glaucoma (PCG), 7 (16.7%) juvenile open-angle glaucoma, and 13 (30.9%) SPG. Mean ages at presentation were 2.57 ± 2.87, 131.96 ± 27.71, and 62.09 ± 65.12 months, respectively. In this study, eyes with PCG presented the earliest, with the highest intraocular pressure (IOP) and thickest central corneal thickness (CCT). The mean number of glaucoma surgeries was 1.48 ± 0.71, with 38.1% of the eyes needing two or more glaucoma surgeries; trabeculectomy was the most frequent glaucoma surgery in this cohort. After surgical intervention, the overall mean IOP dropped from 32.25 ± 12.97 to 18.10 ± 9.23 mm Hg (P < .001). Moreover, the percentage using antiglaucoma medications decreased from 100% to 35.7% at the final visit, as did the number of medications prescribed per eye (2.69 ± 0.92 vs 1.05 ± 1.46, P ≤ .001). Mean best corrected visual acuity (BCVA), in patients who could have their BCVA measured, improved from 0.61 ± 0.61 to 0.53 ± 0.51 logMAR at final follow-up.

CONCLUSIONS

Surgical intervention was shown to provide a well-controlled IOP, decrease dependance on glaucoma medications, and improve BCVA in both PPG and SPG. Multiple surgical interventions may be necessary in the treatment of some pediatric patients with glaucoma. Prognostically, thicker CCT was significantly associated with worse IOP control, more glaucoma surgeries, and more antiglaucoma medications at the final visit. Initial BCVA correlated significantly with BCVA at the final visit. [J Pediatr Ophthalmol Strabismus. 2024;61(3):188-197.].

Anterior chamber proliferative membrane interception (AC-PMI)-enhanced trabeculectomy versus trabeculectomy for treating neovascular glaucoma: protocol for a randomized controlled trial

BACKGROUND

Neovascular glaucoma (NVG) is an irreversible blinding eye disease worldwide and is classified as one of the refractory glaucoma conditions, severely impacting visual function and vision. Unfortunately, effective surgical interventions to improve the prognosis of NVG patients are currently lacking. The study aims to evaluate the efficacy and safety of anterior chamber proliferative membrane interception (AC-PMI)-enhanced trabeculectomy compared to the traditional trabeculectomy.

METHODS

AC-PMI enhanced trabeculectomy versus trabeculectomy for the treatment of NVG is a single-center, prospective, double-arms, and randomized controlled trial of superior efficacy, which will involve 100 NVG inpatients. Patients will be randomly assigned into two groups using the random number table method. One group will undergo trabeculectomy using anti-vascular endothelial growth factor (Anti-VEGF) preoperatively and mitomycin C intraoperatively, while the other group will undergo AC-PMI enhanced trabeculectomy with the same medications (Anti-VEGF and mitomycin C). The patients will be followed up at the baseline and 1 day, 1 week, 1 month, 3 months, 6 months, 12 months, 18 months, and 24 months postoperatively. Meanwhile, we will collect the demographics, characteristics, and examination results and monitor any occurrences of adverse events at each follow-up time.

DISCUSSION

This is an efficacy study of a novel surgical approach for treating neovascular glaucoma. Building upon conventional filtering surgeries, this approach introduces an additional step involving the interception of the proliferative membrane to effectively halt the growth of fibrovascular tissue. This study aims to explore a promising new surgical approach for managing NVG and contribute to the advancement of glaucoma treatment strategies.

TRIAL REGISTRATION

ChiCTR ChiCTR2200055138. Registered on 01 January 2022. https://www.chictr.org.cn/showproj.html?proj=145255.

Outcome of illuminated microcatheter-assisted circumferential trabeculotomy following failed angle surgery in PAX6 aniridic glaucoma: a case report and literature review

BACKGROUND

Aniridia is a rare eye disorder with a high incidence of glaucoma, and surgical intervention is often needed to control the intraocular pressure (IOP). Here, we reported a case of illuminated microcatheter-assisted circumferential trabeculotomy (MAT) performed on an aniridic glaucoma patient following a previous failed angle surgery. The surgical procedures for aniridic glaucoma were also reviewed.

CASE PRESENTATION

A 21-year-old man, diagnosed with aniridic glaucoma, came to our hospital consulting for the poor control of left eye's IOP despite receiving goniotomy surgery 3 years ago. The IOP was 26 mmHg with maximum topical antiglaucoma eyedrops. The central cornea was opaque and the majority of iris was absent. The gonioscopy and ultrasound biomicroscopy (UBM) demonstrated that 360° anterior chamber angle was closed. The whole exome sequencing of peripheral blood confirmed a 13.39 Mb copy number loss at chromosome 11p15.1p13, containing PAX6 and WT1 gene. The 360° MAT surgery was performed on his left eye. At 1-year follow-up, the IOP was 19mmHg with 2 kinds of topical antiglaucoma medications, and the postoperative UBM demonstrated the successful incision of the anterior chamber angle.

CONCLUSIONS

The case presented here exhibited a case of aniridic glaucoma treated by MAT surgery. The MAT surgery may be an effective option for IOP control in aniridic glaucoma patients following a previous failed angle surgery.

Secondary intervention after failed initial intervention for primary congenital glaucoma

AIM

To report on the outcome of subsequent interventions after failed initial intervention for primary congenital glaucoma (PCG).

METHODS

Retrospective chart review of children presenting with PCG and failed the initial glaucoma surgery in Alexandria Main University Hospital from 2005 to 2017. The data included demographics, preoperative, operative and postoperative clinical characteristics. Success was defined as IOP<16mmHg and <20% from the presenting IOP and C/D ratio like or better than presentation.

RESULTS

The charts of 531 (260 right, 49%) eyes of 360 (224 males, 62%) children presenting with PCG and failed the initial glaucoma surgery (58 [31 right, 53%] eyes [10.9%] of 50 [28 males, 56%] children) revealed that at initial presentation, the mean±standard deviation (range, median) of the age of the children subjected to one successful glaucoma procedure and the study children was 8.6±11.7 (0.6-109, 5.2) and 4.9±6.1 (0.5-34.4, 3.0) months, respectively. Each of the study eyes was subjected to 2.6±0.8 (2-5.2) glaucoma procedures. The mean±standard deviation (range, median) duration between the initial and second glaucoma surgery and the duration of follow-up was 6.9±7.8 (0.7-39,3.9) and 61.5±32.1 (12.0-139.1, 60.1) months, respectively. At the final follow-up visit success was reported in 41 (70.1%) eyes by IOP<16mmHg criterion, 39 (67.2%) eyes by IOP>20% reduction criterion and in 28 (out of 35 eyes, 80.0%) by the optic nerve condition (C/D ratio) criterion. Success by all 3 criteria was reported in 25 (out of 35 eyes, 71%) eyes.

CONCLUSIONS

A repeat glaucoma surgical procedure maybe needed in up to 11% of operated PCG eyes, with the subsequent glaucoma surgical procedures being successful by about 70%.

Efficacy of anti-vascular endothelial growth factor and mitomycin C on wound healing after trabeculectomy in glaucoma patients: A meta-analysis

Trabeculectomy is the main surgical treatment for glaucoma, but scar formation during wound healing may lead to surgical failure. In this study, we evaluated the efficacy of anti-vascular endothelial growth factor (anti-VEGF) and mitomycin C (MMC) on wound healing after glaucoma surgery. We have been looking for Pubmed, Embase and other databases. The last time we looked at an electronic database was August 2023. A case control study was conducted to compare the use of anti-VEGF and mitomycin C for the treatment of glaucoma. We used the Cochrane standard methodology for collecting and analysing the data. Based on the criteria of inclusion, we have determined 369 related papers and selected seven eligible trials for data analysis. Three hundred and twenty-six cases were treated with trabeculectomy, of which 166 were injected with anti-VEGF and 160 were given MMC for trabeculectomy. In six trials, anti-VEGF and MMC were not found to have any statistical significance on postoperative wound leakage after surgery (OR, 1.55; 95% CI, 0.71, 3.35 p = 0.27). The three trials showed that anti-VEGF and MMC did not differ in terms of reducing postoperative wound hypotony after surgery (OR, 0.78; 95% CI, 0.20, 3.11 p = 0.73). Five trials demonstrated that anti-VEGF and MMC were not associated with a lower incidence of shallow anterior chamber (OR, 1.17; 95% CI, 0.5, 2.76 p = 0.71). There is no significant difference in the effect of anti-VEGF and MMC on wound healing after glaucoma surgery. A multicentre randomized controlled trial with a larger sample size is needed to confirm this study.

PRESERFLO MicroShunt in Severe Myopia: A Case Report and Review of the Literature

The PRESERFLO™ MicroShunt (MP; Santen Inc., Osaka, Japan) is a minimally invasive bleb surgery (MIBS) manufactured to treat primary open-angle glaucoma (POAG), with lower postoperative adverse effects than with conventional filtering surgeries. We describe here the case study of a 58-year-old woman who presented with bilateral severe myopia with bilateral advanced POAG and unreached target pressure under quadritherapy, who was successfully managed by PM surgery. A review of the literature completes our observation. At presentation, the patient had a spherical equivalent of - 7.50 RE and - 7.75 LE with an IOP of 22 mmHg right and left eye (RLE) under quadritherapy, and with severe bilateral visual field loss, including scotomas within the central 5°. The patient presented with systemic hypertension treated with an antihypertensive drug. Two selective laser trabeculoplasties (SLT), performed 3 months apart, were first tried on the LE, without any change in IOP at 2 months. After considering the high risk of postoperative complications, a PM operation was proposed, with a targeted IOP in the mid-fifteens RLE. The patient's eyes underwent PM surgery with mitomycin C (MMC) MMC0.2 mg/mL for 3 minutes without any complications. The LE required 2 consecutive needlings with 1 mL MMC0.2 mg/mL. At 24 months after surgery, the two eyes gave successful results without the need for any additional medical therapy, and with well-functioning conjunctival blebs. The PM was an effective alternative to the gold standard trabeculectomy in our severely myopic patient. A comparative study between conventional filtering operations and this MIBS in highly myopic patients would confirm our observation.

Evaluating the effect of pulse energy on femtosecond laser trabeculotomy (FLT) outflow channels for glaucoma treatment in human cadaver eyes

BACKGROUND AND OBJECTIVES

Femtosecond laser trabeculotomy (FLT) creates aqueous humor outflow channels through the trabecular meshwork (TM) and is an emerging noninvasive treatment for open-angle glaucoma. The purpose of this study is to investigate the effect of pulse energy on outflow channel creation during FLT.

MATERIALS AND METHODS

An FLT laser (ViaLase Inc.) was used to create outflow channels through the TM (500 μm wide by 200 μm high) in human cadaver eyes using pulse energies of 10, 15, and 20 μJ. Following treatment, tissues were fixed in 4% paraformaldehyde. The channels were imaged using optical coherence tomography (OCT) and assessed as full thickness, partial thickness, or not observable.

RESULTS

Pulse energies of 15 and 20 μJ had a 100% success rate in creating full-thickness FLT channels as imaged by OCT. A pulse energy of 10 μJ resulted in no channels (n = 6), a partial-thickness channel (n = 2), and a full-thickness FLT channel (n = 2). There was a statistically significant difference in cutting widths between the 10 and 15 μJ groups (p < 0.0001), as well as between the 10 and 20 μJ groups (p < 0.0001). However, there was no statistically significant difference between the 15 and 20 μJ groups (p = 0.416).

CONCLUSIONS

Fifteen microjoules is an adequate pulse energy to reliably create aqueous humor outflow channels during FLT in human cadaver eyes. OCT is a valuable tool when evaluating FLT.

A comparative study of cystoid macula edema following glaucoma drainage device surgery versus trabeculectomy

PURPOSE

To assess and compare the risk for development of cystoid macula edema (CME) after glaucoma drainage device (GDD) implantation versus conventional trabeculectomy with mitomycin (trab) for glaucoma.

METHODS

Retrospective review of consecutive patients receiving trab or GDD implantation between 2016 and 2018. Inclusion criteria were availability of pre- and postoperative spectral domain optical coherence tomography (SD-OCT) of the macula. SD-OCT images were evaluated for presence of CME qualitatively, central subfield thickness (CST) and macular volume (MV).

RESULTS

73 eyes could be included, 42 received trab and 31 GDD surgery. Eyes receiving trab on average had 0.8 ± 0.8 previous intraocular operations, while eyes with GDD implantation had 3.1 ± 1.9 (p < 0.001). Occurrence of postoperative CME was significantly more frequent after GDD implantation (6 out of 31 (19.4%)) than after trab (2 out of 42 eyes = 4.8%), (p = 0.049). Mean preoperative CST as well as MV was comparable in both groups (CST before trab: 282.7 ± 23.0 µm, CST before GDD 284.2 ± 27.3 µm, p = 0.287; MV before trab: 7.8 ± 1.1 mm3, MV before GDD: 8.0 ± 0.8mm3, p = 0.305). Mean postoperative CST and MV were significantly higher after GDD (CST 338.5 ± 129.3 µm, MV 8.8 ± 2.6 mm3) than after trabeculectomy (CST 290.6 ± 60.2 µm, p = 0.038; MV 7.8 ± 1.2mm3, p = 0.039).

CONCLUSIONS

In real-life conditions, GDD surgery seems to be associated with a higher risk to develop CME when compared to conventional trabeculectomy. This information may be helpful for glaucoma surgeons to advise the patients on postoperative risks of surgery.

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.

Wound modulation in glaucoma surgery: The role of anti-scarring agents

Filtration surgery is one of the most frequently performed surgeries in the management of glaucoma, and trabeculectomy is considered the gold standard surgical technique for the same. Though trabeculectomy has been reported to have an excellent initial success rate, about 30% of them fail in 3 years, and nearly 50% of them fail in 5 years. The most significant risk of failure still seems to be wound scarring, especially episcleral fibrosis, leading to bleb failure. As a result, it is essential to explore the role of anti-scarring agents, including mitomycin C, and 5-fluorouracil in wound modulation and improving the bleb survival rate. Since these agents are widely used in trabeculectomy, it is crucial to understand the various modes of application, advantages, and adverse effects of these agents. On an evidence-based approach, all these points have been highlighted in this review article. In addition, the newer agents available for wound modulation and their scope for practical application are discussed.

Indocyanine green-assisted goniotomy in eyes with hazy cornea

Corneal haze, due to edema or opacity, is a major contraindication for performing ab interno angle surgeries such as goniotomy in children with primary congenital glaucoma (PCG), despite otherwise favorable surgical outcomes expected in these patients. In this case series involving patients of PCG with moderate corneal haze, the authors describe a technique for performing goniotomy in cases with compromised visibility by using indocyanine green (ICG) to aid in the visualization of angle structures. The authors used 0.2% ICG intracamerally, which stained the anterior and posterior trabecular meshwork (TM) with different intensities, before proceeding with goniotomy. The junction between the two zones was discernible due to the contrast imparted by ICG staining, despite poor visibility, allowing the surgeon to incise the TM at the correct site. The possibility of performing goniotomy in such patients with the help of ICG can revolutionize our surgical approach to patients with PCG and corneal edema.

Comparison of the safety and efficacy of Mitomycin C 0.02% used intra-operatively by subconjunctival injection versus direct scleral application using sponges in phacotrabeculectomy: A prospective randomized controlled trial

PURPOSE

To compare the safety and efficacy of subconjunctival injection (MMC: 0.02%) to those with subconjunctival application of sponges soaked in Mitomycin C (MMC: 0.02%) intra-operatively in patients who underwent phacotrabeculectomy.

METHODS

A total of 68 patients undergoing phacotrabeculectomy were randomized into two groups; the sponge group received 0.02% MMC-soaked sponges (n = 38), and the injection group received subconjunctival injection of 0.02% MMC (n = 30). The primary outcome was post-operative mean intra-ocular pressure reduction (IOP). The secondary outcomes were bleb morphology using Indiana Bleb Appearance Grading Score (IBAGS) and anterior segment optical coherence tomography (AS-OCT), post-operative use of 5-fluorouracil, and complications rates. These were compared at 1 week and 1, 3, and 6 months post-operatively. Complete success was defined as ≥30% reduction in IOP without anti-glaucoma medications.

RESULTS

In sponge and injection groups, the mean pre-operative IOP was 29.1 ± 8.1 and 29.8 ± 8.8 mmHg, respectively. At 6 months, IOP in sponge and injection groups reduced by 52% (14 ± 3.6 mmHg, P < 0.001) and 50% (15.2 ± 4.1 mmHg, P < 0.001), respectively. Complete success was observed in 90.9% in the sponge group and 95.83% in the injection group. Both groups had diffuse, shallow, relatively avascular blebs at 6 months using IBAGS and AS-OCT. A few complications were seen in the sponge group during this period, which were not vision-threatening.

CONCLUSION

Subconjunctival MMC injection is an effective, safe, convenient, and time-saving alternative to sponge-soaked delivery of MMC in phacotrabeculectomy.

Histopathologic correlates of trabecular meshwork in microincisional trabeculectomy

PURPOSE

To report the histopathologic correlates of trabecular meshwork (TM) specimens procured by microincisional trabeculectomy (MIT) for different severities of glaucoma (early glaucoma: visual field mean deviation [MD] <-6 dB, moderate glaucoma: MD from - 6 to - 12 dB, and advanced glaucoma: MD <-12 dB).

METHODS

TM specimens from four patients undergoing MIT with or without cataract surgery were analyzed by routine histopathology for structural changes. The number of cells, the number of cells with spindle-shaped nuclei suggestive of epithelial-mesenchymal transformation (EMT), and the distance between the trabecular beams were calculated using different tools on freely available ImageJ software using the line or pint/count tool.

RESULTS

The TM specimens procured from two early and two advanced glaucoma cases showed decreasing cellularity and decreased compact arrangement of the trabecular beams in severe disease stages. The number of cells and preserved architecture in all four specimens were evident, with > 50 cells being present per section in all four cases despite the glaucoma being of advanced disease stage in two patients.

CONCLUSION

The TM specimens obtained from MIT can be utilized for downstream analysis using different molecular methods for studying the molecular events in the tissue from early to severe glaucoma.

Two-year outcomes of anterior versus posterior scleral application of mitomycin C-soaked sponge in trabeculectomy

PURPOSE

To compare the safety and efficacy of two different application methods of mitomycin C (MMC)-soaked sponge in trabeculectomy.

STUDY DESIGN

Retrospective study.

METHODS

We included 71 eyes of 71 patients that had undergone trabeculectomy. In the anterior scleral application group, 36 eyes were treated using the long side of the MMC-soaked sponge placed parallel to the limbus. The efficacy and safety in these eyes were compared with eyes treated with the posterior scleral application group, consisting of 35 eyes treated with the long side of the MMC-soaked sponge placed perpendicular to the limbus. The follow-up period was 2 years. The safety of the procedure, including bleb morphology and complications, was the primary outcome, while the success rate was the secondary outcome.

RESULTS

The cumulative success rate at 2 years postoperatively was 94.4% in the anterior and and 94.3% in the posterior scleral application group (P = 1.000). However, with the posterior scleral application of the MMC-soaked sponge, blebs were more low-lying (P = 0.048), less in extent (P < 0.001), more normally vascularized (P = 0.027) and more posteriorly directed (P < 0.001). Furthermore, the incidence of thin-walled cystic bleb (P = 0.028) and bleb leakage (P = 0.025) was significantly lower in the posterior scleral application group than in the anterior group.

CONCLUSION

Although there were similar success rates, the posterior scleral application of MMC-soaked sponge with trabeculectomy was safer with a better bleb morphology than the anterior scleral application.

Quantification of Postoperative Inflammation in Laser and Surgical Procedures for Glaucoma with Laser Flare Photometry: A Review of the Literature

PURPOSE

To review the application of laser flare photometry (LFP) in the objective quantification of aqueous flare (anterior chamber inflammation) post laser and surgical procedures for glaucoma.

METHODS

A search was undertaken using the following: PubMed (all years), the Web of Science (all years), Ovid MEDLINE (R) (1980 to 30 March 2023), Ovid MEDLINE (R) Daily Update 30 March 2023, MEDLINE and MEDLINE non-indexed items, Embase (1980-2021, week 52), Ovid MEDLINE (R) and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1980 to 30 March 2023), CENTRAL (including Cochrane Eyes and Vision Trials Register), metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (www.who.int/ictrp/search/en). Search terms included "aqueous flare," "anterior chamber inflammation," "tyndallometry," "laser flare photometry" combined with "laser," "iridotomy," "trabeculoplasty," "cataract surgery," "phacoemulsification," "glaucoma surgery," "minimally invasive glaucoma surgery," "trabeculectomy," "aqueous shunt," "glaucoma drainage" and "cyclophotocoagulation."

RESULTS

The majority of studies utilizing laser flare photometry in grading flare have been post laser trabeculoplasty. The degree of flare produced varies according to the type of glaucoma laser or surgery performed, with filtration procedures and glaucoma drainage devices having marked and prolonged detectable levels. Aqueous flare in cyclodestructive procedures positively correlated with intraocular pressure (IOP) reduction.

CONCLUSION

In comparison to clinician grading, laser flare photometry provides a more objective measure of post-surgical inflammation in eyes that have undergone laser and surgery for glaucoma. Further research is warranted into how this instrument can be utilized to identify eyes at high risk of failure and other adverse outcomes after glaucoma surgery.

Ab-Externo MicroShunt versus Trabeculectomy in Primary Open-Angle Glaucoma: Two-Year Results from a Randomized, Multicenter Study

PURPOSE

To compare the effectiveness and safety of the MicroShunt (Santen Inc) versus trabeculectomy in patients with primary open-angle glaucoma (POAG).

DESIGN

Prospective, randomized, multicenter trial conducted in the United States and Europe.

PARTICIPANTS

Adult patients (aged 40-85 years) with mild to severe POAG inadequately controlled on maximum tolerated medical therapy and intraocular pressure (IOP) ≥ 15 mmHg and ≤ 40 mmHg.

METHODS

Patients were randomized 3:1 to stand-alone MicroShunt implantation (n = 395) or trabeculectomy (n = 132), both augmented with mitomycin C (MMC) 0.2 mg/ml for 2 minutes.

MAIN OUTCOME MEASURES

The primary effectiveness end point was surgical success, defined as ≥ 20% reduction in mean diurnal IOP from baseline with no increase in glaucoma medications. Secondary end points included changes in mean IOP and medication use from baseline and the need for postoperative interventions.

RESULTS

At 2 years, the rate of surgical success was lower in the MicroShunt group than in the trabeculectomy group (50.6% vs. 64.4%, P = 0.005). Mean diurnal IOP was reduced from 21.1 ± 4.9 mmHg at baseline to 13.9 ± 3.9 mmHg at 24 months in the MicroShunt group and from 21.1 ± 5.0 mmHg at baseline to 10.7 ± 3.7 mmHg at 24 months in the trabeculectomy group (P < 0.001 compared with baseline in both groups). Mean medication use decreased from 3.1 to 0.9 in the MicroShunt group and from 2.9 to 0.4 in the trabeculectomy group (P < 0.001 compared with baseline in both groups). Adverse events at 2 years were generally similar in the 2 groups, except that hypotony was more common in eyes undergoing trabeculectomy (51.1% vs. 30.9%, P < 0.001). Repositioning or explantation of the implant occurred in 6.8% of MicroShunt patients. The majority of these patients had device removal at the time of subsequent glaucoma surgery. Vision-threatening complications were uncommon in both groups.

CONCLUSION

At 2 years, both the MicroShunt and trabeculectomy provided significant reductions in IOP and medication use, with trabeculectomy continuing to have greater surgical success.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Early Outcomes of Combined Phacoemulsification and Ab Interno Tanito Microhook Trabeculotomy in Open-Angle Glaucoma

PURPOSE

To study the early postoperative efficacy and safety of an Ab Interno microhook trabeculotomy (microLOT) combined with cataract surgery in patients with open-angle glaucoma.

METHODS

This prospective, randomized, interventional study was conducted on consecutive patients with visually significant cataract and mild-moderate open-angle glaucoma. One hundred fourteen patients were included for analysis. The patients were randomized to undergo microhook trabeculotomy with phacoemulsification (group 1) or phacoemulsification alone (group 2). All patients were evaluated on postoperative day 1, 15, and 30, as well as 3, 6, and 12 months postoperatively. A P value < 0.05 was considered statistically significant. Baseline and follow-up visits were compared to determine significant differences in the number of antiglaucoma medications (AGMs), intraocular pressure (IOP), and best-corrected visual acuity.

RESULTS

There were 57 patients in each group. The baseline characteristics were similar between the 2 groups, except the number of AGMs, which was greater in group 2. The mean preoperative IOP for group 1 (phaco-microLOT) was 26.5 mmHg ± 5.2 and group 2 (phaco-alone group) was 25.3 mmHg ± 3.1 which decreased to 12.5 mmHg ±3.6 (P < 0.001) and 20.0 mmHg ± 2.7(P < 0.001) at 12 months, respectively. Logarithm of the minimum angle of resolution visual acuity improved from 0.48 (interquartile range [IQR], 0.30-0.60) preoperatively to 0.00 (0.00-0.18) postoperatively (P < 0001) in group 1 and improved from 0.30 (IQR, 0.30-0.48) to 0.00 (0.00-0.00) in group 2 (P < 0.001). In group 1, the mean (standard deviation [SD]) AGM used preoperatively was 0.6 (0.9) which was significantly reduced to 0.2 (0.5) at 12 months postoperatively, whereas in group 2, at 12 months, the mean (SD) AGM used was reduced from 1.4 (0.6) to 1.1 (0.9). In group 1, 90.3% of eyes achieved complete success at the end of 1 year. The most common complication was hyphema, noted in 4 patients with 1 eye requiring an anterior chamber washout.

CONCLUSION

Ab interno microhook trabeculotomy (microLOT) combined with phacoemulsification in patients with open-angle glaucoma is an efficacious procedure with relatively minimal complications.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Outcome of combined trabeculectomy with cataract surgery in patients on prostaglandin analogs and aqueous suppressants

PURPOSE

To compare the effect of prostaglandin analogs (PGA) against other glaucoma medications (non-PGA) on the intraocular pressure (IOP) outcomes of combined trabeculectomy with phacoemulsification, and the conjunctival cell profile in persons with primary open-angle (POAG) and pseudoexfoliation glaucoma (PXFG).

METHODS

A prospective cohort study was conducted among 116 patients with POAG or PXFG on glaucoma medications for a minimum of 3 months undergoing glaucoma triple procedure. Patients were divided into two groups (PGA and non-PGA) based on preoperative exposure to PGA. IOP outcomes were assessed for up to 2 years. Conjunctival biopsy specimens were obtained at the time of surgery, and histopathological analysis was performed.

RESULTS

Forty-two patients were in the PGA group, 67 were in the non-PGA group, and seven were lost to follow-up. The non-PGA group had lesser mean postoperative IOP and needed fewer postoperative medications compared to the PGA group in all visits up to 2 years. The non-PGA group had better complete success rate (50.7% vs. 14.3%, P < 0.001). Kaplan-Meier survival estimates showed a significant difference in cumulative complete success rate between non-PGA (67%) and PGA (26%) by 24 months ( P < 0.001). The Cox proportional model showed the type of drug to be significantly associated with surgical failure. Histopathological analysis revealed that the PGA group had higher numbers for each type of inflammatory cell (except mast cells) compared to the non-PGA group.

CONCLUSION

Patients on PGA are likely to have a higher postoperative IOP and may need more medications for IOP control after a glaucoma triple procedure.

Hypotony in the early postoperative period after MicroShunt implantation versus trabeculectomy: A registry study

PURPOSE

A comparison of the safety and efficacy of the MicroShunt versus trabeculectomy in the early postoperative period, with a particular focus on hypotony.

METHODS

In this registry study, we evaluated 200 eyes of 200 glaucoma patients who underwent filtration surgery at Oslo University Hospital between 2017 and 2021. Of these patients, 100 had a Preserflo MicroShunt (Santen) implantation and 100 had a trabeculectomy procedure. The patients were examined per standard hospital protocol after filtration surgery. Data were extracted from the 4- and 8-week visits. We defined hypotony as intraocular pressure (IOP) < 6 mmHg.

RESULTS

The mean preoperative IOP was 20.6 ± 7.1 mmHg in the MicroShunt group and 21.6 ± 7.1 mmHg in the trabeculectomy group, and the patients used a mean of 3.0 ± 0.9 and 3.1 ± 0.9 glaucoma medications, respectively. After 8 weeks, IOP was reduced to 10.4 ± 5.4 mmHg and 11.3 ± 4.6 mmHg, respectively (p = 0.23). During the early postoperative period, hypotony was registered in 63% of the MicroShunt patients and in 21% of the patients in the trabeculectomy group (p < 0.001); and 11% and 1%, respectively, of the patients developed choroidal detachments (p < 0.003). One patient in the MicroShunt group required reoperation due to hypotony.

CONCLUSIONS

In this registry study, we found that the Preserflo MicroShunt and trabeculectomy had equally satisfactory IOP-lowering effects during the early postoperative period. In this same period, a high number of patients in the MicroShunt group developed hypotony.

Optimal Performance of Selective Laser Trabeculoplasty: Results from the Swedish Optimal SLT Multicenter Randomized Controlled Trial

PURPOSE

Selective laser trabeculoplasty (SLT) is a first-line treatment for glaucoma and ocular hypertension. However, due to insufficient comparative evidence in efficacy and safety, several SLT treatment protocols are currently used in practice. The objective of this trial was to compare the clinical outcomes of the 4 most significant SLT variants.

DESIGN

Prospective, multicenter, masked, randomized controlled trial (RCT).

PARTICIPANTS

Four hundred patients with glaucoma or ocular hypertension. The cohort consisted of both treatment-naive patients and patients undergoing glaucoma treatment, at different stages of disease.

METHODS

Selective laser trabeculoplasty was performed with 50 ± 5 laser spots in 180 degrees or with 100 ± 10 spots in 360 degrees. The laser power was titrated to either just below the cavitation bubble level ("standard energy") or to a level producing cavitation bubbles at 50% to 75% of laser applications ("high energy"). Thus, 4 different treatment protocols were included - 180/standard, 180/high, 360/standard, and 360/high. The study adhered as close as possible to regular clinical management, but within a scientific framework.

MAIN OUTCOME MEASURES

Reduction of intraocular pressure (IOP) 1 to 6 months after SLT. The proportion of patients achieving a 20% IOP reduction without any further intervention. Time to glaucoma treatment escalation in a Kaplan-Meier survival analysis.

RESULTS

SLT performed with the 360/high protocol was shown to be superior regarding all primary endpoints. The IOP reduction 1 to 6 months after SLT was 5.4 mmHg in the 360/high group, compared to 3.4, 3.2, and 4.2 mmHg with the 180/standard, 180/high, and 360/standard protocols, respectively (P < 0.001). Furthermore, the success rate after 6 months was significantly higher -58.3%, compared with 30.2%, 29.3%, and 41.7% (P < 0.001). The median time to glaucoma treatment escalation was more than twice as long with 360/high SLT -1323 days, compared to 437 days, 549 days, and 620 days (P < 0.001). Although postoperative discomfort was more frequent with the 360/high protocol, symptoms were generally mild and transient. Adverse events were rare in all groups.

CONCLUSIONS

The magnitude and longevity of SLT results increases substantially if SLT is performed according to the 360/high protocol, without compromising safety. Therefore, we recommend that 360/high SLT be considered as standard treatment.

FINANCIAL DISCLOSURES

The authors have no proprietary or commercial interest in any materials discussed in this article.