Bleb Vascularity Research Articles

Bleb vessel density as a predictive factor for surgical revisions after Preserflo Microshunt implantation.

Bleb failure is a common complication after glaucoma filtration surgery. Different bleb classification schemes incorporating filtration bleb vascularization have been proposed, but the reported correlation with intraocular pressure (IOP) has been variable, possibly because of subjective vascularization grading. The purpose of the present study was to evaluate bleb vascularization after Preserflo Microshunt (PM) implantation using anterior segment OCT-angiography (AS-OCTA) as a biomarker for bleb failure. Twenty-three eyes of twenty-three patients underwent PM implantation. Up to 12 months after surgery PM scleral passage-centred AS-OCTA measurements (PLEX Elite 9000) for bleb-vessel density (BVD) determination were performed and IOP as well as necessity for surgical revisions (needling and open revision) were documented. After multi-step image analysis (region of interest definition, artefact removal, binarization, BVD calculation), the predictive value of early postoperative BVD for surgical revisions was assessed using logistic regression modelling. Baseline IOP (23.57 ± 7.75 mmHg) decreased significantly to 8.30 ± 2.12, 9.17 ± 2.33 and 11.70 ± 4.40 mmHg after 1, 2 and 4 week(s), and 13.48 ± 5.83, 11.87 ± 4.49, 12.30 ± 6.65, 11.87 ± 3.11 and 13.05 ± 4.12 mmHg after 2, 3, 6, 9 and 12 month(s), respectively (p < 0.001). Nine patients (39%) needed surgical revisions after a median time of 2 months. Bleb vessel densities at 2 and 4 weeks were significantly associated with future surgical revisions upon logistic regression analysis (2 W/4 W likelihood-ratio test p-value: 0.0244/0.0098; 2 W/4 W area under the receiver operating characteristics curve: 0.796/0.909). Filtration bleb vessel density can be determined using AS-OCTA in the early postoperative period and is predictive for bleb failure after PM implantation.

Topical Administration of Bevacizumab to Facilitate the Functional Filtering Bleb After Trabeculectomy in the Rabbit.

Purpose: To evaluate the effects of bevacizumab in 3 different application methods, subconjunctival injection (SCI), hyaluronic acid retardant (HAR), and eye drop (ED), on attenuating scar formation in the filtering bleb. Methods: Trabeculectomy (TRAB) was performed on New Zealand rabbits. TRAB rabbits were intervened with bevacizumab SCI, HAR, ED, or mitomycin C, respectively. Intraocular pressure (IOP) of 1, 7, 14, and 28 days after TRAB was recorded, and the bleb survival rate was analyzed. Bleb height, area, and vascularization were evaluated using anterior segment optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) at 7, 14 and 28 days after surgery. A histopathology examination of the bleb tissue was performed. The expression levels of vascular endothelial growth factor (VEGF)-A, interleukin (IL)-1α, tumor necrosis factor-alpha (TNF-α), transforming growth factor-β1 (TGF-β1), and α-smooth muscle actin (α-SMA) were measured by Western blot. Results: Bevacizumab significantly reduced postoperative IOP and increased the survival of the filtering bleb, especially in the ED group. Less vascularization was shown in the SCI, HAR, and ED groups. Histopathological results showed the fewest levels of scarring and fibrosis in the ED group. The local VEGF-A, IL-1α, and TNF-α expression levels after bevacizumab ED were decreased, combined with suppression of TGF-β1 and α-SMA. Conclusions: Postoperative use of bevacizumab EDs was an effective application method for improving surgical outcomes after TRAB in rabbits. It might be effective in preventing scarring of the filtering bleb by antivascularization and anti-inflammation.

Assessing safety and success after using bevacizumab, 5-fluorouracil or placebo in primary trabeculectomy. A prospective randomized placebo controlled 1-year follow-up study

Purpose The aim of this study was to determine whether glaucoma patients after trabeculectomy could benefit more from subconjunctival injections of bevacizumab than 5-FU or placebo. Methods and results Fifty-one eyes of 51 patients were recruited for primary MMC (0.2 mg/mL for 1 min) augmented trabeculectomy. 17 patients were randomly assigned to receive 1.25 mg (0.05 mL) of bevacizumab augmentation, 21 patients were assigned to receive 0.1 mL of 50 mg/mL 5-FU and 13 patients were assigned to a control group receiving a normal saline injection as a placebo. Initial recruitment included 58 patients, but seven patients had to be excluded from the study for various reasons. Postoperative follow up of IOP and bleb characteristics was carried out at 1 day, 1 week, 3 weeks, 6 weeks, 6 months and 1 year after surgery. All analyses where carried out by two masked clinicians. IOP reduction was statistically significant (p < 0.05) across all three groups between baseline visit and final 1-year postoperative visit. There was no significant difference of the final average IOP values between the three groups. Bleb evaluation was made using the Moorfields bleb grading system (MBGS) after 1 year follow up. Central bleb area was statistically greater in the Bevacizumab group when compared with the 5-FU group but not with the placebo group. The vascularity of the central bleb was significantly different between the groups with the Bevacizumab group showing the least vascularity. Vascularity of the peripheral bleb was also decreased in the Bevacizumab group when compared with the placebo group but not with the 5-FU group. Conclusion The 12-month IOP results showed no significant differences between the groups of patients after Bevacizumab, 5-FU or placebo to augment primary MMC enhanced trabeculectomy. However, by the analysis of bleb morphology there was a significant difference in terms of central bleb area and vascularity.

Changes in the morphology of the hyperemic blebs in eyes undergone trabeculectomy with mitomycin C after injection of triamcinolone acetonide during one-year follow-up.

To track changes in the morphology of hyperemic blebs in eyes undergone trabeculectomy with mitomycin C 0.02% (MMC) after triamcinolone acetonide (TA) injection. A total of 30 eyes of 30 patients with localized or diffuse hyperemia after trabeculectomy with MMC were enrolled in this prospective interventional case series. Two milligrams of TA were injected at the site of maximal injection. Bleb morphology was graded using Indiana Bleb Appearance Grading Scale (IBAGS), and the Moorfields Bleb Grading System (MBGS) 1week, 1month, 3months, 6months, and 1year after injection. Failure was defined as intraocular pressure (IOP) more than predefined target IOP for each eye, need for an additional surgical procedure, IOP less than 6mmHg, and loss of Light Perception (LP) vision. A total of 27 patients completed a 1-year follow-up period and were included in the final analysis. The mean time interval from trabeculectomy to injection of TA was 5.98 ± 2.57weeks. The bleb height and vascularity in the IBAGS system decreased significantly after the intervention (p < 0.05), with an increase in bleb extension (p = 0.006). Using MBGS, the bleb area did not change significantly following TA injection (p = 0.056) but its height and vascularity significantly decreased in both central and peripheral areas and the surrounding conjunctiva (p = 0.032). The development of a mature cataract was the only complication that could be attributed to TA injection. Injection of TA in hyperemic failing blebs improves bleb morphology by decreasing vascularity and height while increasing the extent with an acceptable safety profile.

The Efficacy and Safety of Trehalose in Primary Trabeculectomy with Mitomycin C: A Report of Early Findings.

ObjectiveTo compare bleb morphology and tear tests of glaucoma patients who used trehalose and those who did not use after primary trabeculectomy with mitomycin C (MMC) during the early post-operative period.MethodsThis retrospective study included two groups: Group 1 using Trehalose + hyaluronic acid (THA) after primary trabeculectomy with MMC (n = 19) and Group 2 undergoing primary trabeculectomy with MMC (n = 16). The preoperative and postoperative intraocular pressure (IOP), the results of Schirmer, and tear break-up time tests were analyzed. Postoperative bleb morphology was also evaluated at the 1st day, and 1st and 2nd weeks, and 1st and 2nd months.ResultsThere was no statistically significant difference in preoperative IOP, Schirmer test or tear break-up time between groups. The mean horizontal extent of the blebs was significantly wider in Group 1 at the first week (p= 0.02). Bleb vascularization was also found to be lower in Group 1 at the second week (p= 0.001). The mean bleb height and horizontal extent were significantly higher in Group 1 at the first month (p=0.02, p= 0.03, respectively). The mean bleb horizontal extent was significantly higher in Group 1 at the second month (p= 0.03).ConclusionThe use of trehalose improved surgical success of primary trabeculectomy with MMC in terms of IOP control, post-operative complications, and bleb morphology during the early postoperative period. Trehalose might contribute to wound healing which led to an ideal bleb.

Novel combination therapy reduces subconjunctival fibrosis after glaucoma filtration surgery in the rabbit model.

Glaucoma filtration surgery (GFS) is limited by subconjunctival, episcleral and scleral fibrosis sealing the trabeculectomy and scarring the filtering bleb. Mitomycin-C (MMC) is commonly applied intraoperatively to the subconjunctival and/or intrascleral space to reduce scarring and promotes GFS success but is associated with postoperative scleral melting and bleb leaks. IP-10 peptide (IP-10p), an ELR-negative CXC chemokine mimetic and inhibitor of fibroblast function, may be an alternative or adjunct to current postoperative GFS treatments. This study sought to determine if IP-10p produces histological changes in tissue remodelling, vascularity and fibrosis that enhance bleb survival after GFS. Rabbits underwent tube-assisted filtration surgery on the right eye with either: (a) IP-10p injected into bleb at time of surgery and postoperative days 2, 4 and 7, (b) intraoperative MMC or (c) intraoperative MMC plus IP-10p injected into bleb at time of surgery and postoperative days 2, 4 and 7. Left contralateral eyes were treated with balanced salt solution (BSS). IP-10p-treated blebs demonstrated reduced collagen deposition, cellularity and overall reduction of scar formation compared to BSS-control. Bleb vascularity was reduced compared to BSS-control and MMC treatment groups. Additionally, IP-10p/MMC treated eyes demonstrated an increased number of conjunctival goblet cells in bleb histology compared to the dramatic loss seen with MMC treatment alone. This study demonstrates that IP-10p significantly reduces histological scarring compared to BSS or MMC alone, does not damage the conjunctiva to the extent of current standards, and may be an alternative or adjunct to MMC for those undergoing GFS.

Analysis of bleb morphology after CLASS with ultrasound biomicroscopy and clinical grading scale.

Filtration in the area subjected to CO2 laser-assisted sclerectomy surgery (CLASS) is described using ultrasound biomicroscopy (UBM) and the clinical grading scale to evaluate the mechanism of intraocular pressure (IOP) reduction. Twenty-eight patients with open-angle glaucoma underwent CLASS. The Indiana Bleb Appearance Grading Scale evaluation was performed 1 month after surgery to determine bleb height, extent, vascularity, and leakage. UBM was used to describe and measure the surgical area. Bleb morphology, the size of the scleral lake, scleral route, and trabeculodescemetic membrane (TDM) thickness were examined. One month after CLASS, IOP significantly decreased from 20.46 ± 3.92 mmHg to 12.71 ± 2.99 mmHg, and the anterior chamber depth significantly more shallow, from 2.75 ± 0.36 mm to 2.61 ± 0.33 mm(p < 0.05). Shallow uplift occurred in 71.43% of the blebs, and 64.29% of the blebs were within 1 to 2 h; 82.15% showed mild or moderate vascular hyperemia, and the Seidel test was negative. UBM showed that all eyes had an intact TDM, with a mean thickness of 99.3 ± 22.2 μm; 21 eyes (75%) had L-type (low reflective). The scleral lake anteroposterior length, height, and transversal length were 2.247 ± 1.831 mm, 0.520 ± 0.234 mm, and 3.312 ± 0.423 mm, respectively. The TDM thickness and postoperative IOP were positively correlated, and the size of the scleral lake was not correlated with IOP reduction. Four eyes (14.29%) exhibited cyclodialysis. UBM examination indicated the aqueous humor drainage route. In the early stage after CLASS, subconjunctival and choroidal drainage routes might be the major mechanism underlying IOP reduction. Mild and moderate congestion of bleb blood vessels warrant attention to avoid early bleb scarring.

Predictive Value of Bleb Vascularity after Mitomycin C Augmented Trabeculectomy.

Background: To evaluate the relationship between bleb vascularity and surgical outcome one year after mitomycin C (MMC) augmented trabeculectomy. Methods: This was a prospective study of 51 eyes of 44 patients after MMC-augmented primary trabeculectomy with follow-up of 12 months. The total vessel area of a bleb was measured with ImageJ software on color photographs of the bleb on day 1 and 14, then months 1, 3, 6 and 12 after trabeculectomy. Blebs were classified clinically as successful (intraocular pressure (IOP) ≤ 18 mmHg and a >30% reduction in IOP without antiglaucoma medications or additional surgical interventions) or failed. Linear regression analysis was performed to determine the correlation of bleb vascularity with IOP and outcome. Results: At 1 year, 40 eyes (78.4%) were classified as successful and 11 eyes (21.6%) as failed. The mean bleb vascularity at 1, 3 and 12 months after surgery was significantly higher in failed blebs (16.31% vs. 13.01%, p = 0.005, 14.93% vs. 10.15%, p = 0.001, 8.99% vs. 6.37%, p = 0.011, respectively). There were no significant differences in mean bleb vascularity at 1 and 14 days postoperatively in successful and failed blebs. The results revealed a significant association between vessel area at 1 and 3 months after trabeculectomy with IOP at 6 months postoperatively (p = 0.005 and p = 0.009, respectively). Conclusions: In this prospective study, we demonstrated a strong relationship between bleb vascularity and the surgical outcomes of trabeculectomy. Vascularity of the filtering bleb during early postoperative period was not correlated with IOP or success of trabeculectomy at one year. Increased bleb vascularity 1, 3 and 12 months after trabeculectomy appears to predict surgical failure at 1 year after trabeculectomy.

Injected Versus Sponge-Applied Mitomycin C (MMC) During Modified Trabeculectomy in New Zealand White Rabbit Model.

PurposeMitomycin C is routinely applied during trabeculectomy surgeries to enhance bleb survival after glaucoma filtration surgery. The current approach involves placing cellulose sponges soaked in mitomycin C at a standard concentration onto bare sclera for a predetermined duration, which varies among surgeons. The purpose of this study was to compare the effects of sponge-applied versus intra-Tenon injection of mitomycin C during modified trabeculectomy.MethodsTwo groups of five New Zealand White rabbits underwent glaucoma filtration surgery with either preoperative intra-Tenon injection of mitomycin C or intraoperative application of mitomycin C using a cellulose sponge. Postoperative intraocular pressure was recorded weekly, and eyes were enucleated and sent for pathological examination and histological analysis.ResultsAn intra-Tenon injection of mitomycin C resulted in decreased intraocular pressure measurements and bleb vascularity compared to the controls but increased levels compared to the sponge-applied group. Collagen deposition and cellularity were reduced and the goblet cell population was increased in the intra-Tenon injection group.ConclusionsThis study shows that an intra-Tenon injection can be an effective method for administering mitomycin C compared to the standard-of-care approach of mitomycin C being sponge applied onto bare sclera. Mitomycin C injection led to a greater reduction in intraocular pressure and inhibition of fibroblasts. The associated goblet cell population that can lead to increased mitomycin C toxicity-related morbidity was minimized with the intra-Tenon injection compared to the sponge-applied MMC treatment. Therefore, patients with ocular surface disease may benefit from an intra-Tenon injection.Translational RelevanceThis project provides a direct, qualitative assessment in an animal model of common techniques within glaucoma filtration surgery for drug delivery to improve surgical success.

A Randomized Controlled Trial Comparing Subconjunctival Injection to Direct Scleral Application of Mitomycin C in Trabeculectomy

To compare the efficacy of intraoperative scleral application with subconjunctival injection of mitomycin C (MMC) in trabeculectomy. Prospective, randomized, interventional study. This study took place in a single clinical practice in an academic setting. Patients had medically uncontrolled glaucoma as indicated by high intraocular pressure (IOP), worsening visual field, or optic nerve head changes in whom primary trabeculectomy was indicated. Patients were older than 18 years with medically uncontrolled glaucoma and no history of incisional glaucoma surgery. Patients were randomized to MMC delivered by preoperative subconjunctival injection or by intraoperative direct scleral application using surgical sponges during trabeculectomy. Comprehensive eye examinations were conducted at 1day, 1week, 6weeks, 3months, and 6months postoperatively. Subconjunctival 5-fluorouracil injections were given postoperatively, as needed. The primary outcome was the proportion of patients who demonstrated IOP of <21mm Hg and ≥30% reduction in IOP from baseline. Secondary outcome measures included the number of IOP-lowering medications, bleb morphology using the Indiana Bleb Appearance Grading Scale, and complication rates. Participants (n= 100) were randomized into groups matched for baseline demographics, glaucoma status, and baseline IOP. At 6months, there were no significant differences between the injection (n= 38) and sponge (n= 40) groups in surgical success (P= .357), mean IOP (P= .707), number of glaucoma medications (P= 1.000), bleb height (P= .625), bleb extension (P= .216), bleb vascularity (P= .672), or complications rates. Both techniques of MMC delivery (subconjunctival injection and direct scleral application) resulted in comparable surgical outcomes and bleb morphologies.

Evaluation of Bleb Characteristics after Trabeculectomy and Glaucoma Implant Surgery in the Rabbit

The characteristics of the conjunctival bleb are some of the most important factors for the surgical success of glaucoma filtering surgery. To improve surgical outcome, we investigated bleb histology after 3 different glaucoma surgeries. Surgery was performed in 21 white rabbits. Rabbits were randomized to trabeculectomy or implantation with EX-PRESS or a silicone tube (each n = 7). Bleb survival, intraocular pressure (IOP), and vascularity were evaluated. At 6 weeks, eyes were enucleated for histological analysis. Postoperative IOP at 2 weeks was significantly lower in the trabeculectomy and the EX-PRESS group than in the silicone tube group (p = 0.037) but not thereafter. Postoperative bleb survival (p = 0.542) and vascularity (p = 0.988) were similar among the 3 groups. Histologically, a capsule showing mild fibroblast proliferation associated with intercellular collagen was present around the surgical site. The thickness of the bleb was similar among all experimental groups, but it was significantly greater than in controls (p < 0.05). The inflammatory area did not differ between the EX-PRESS and the silicone tube group but was significantly greater in the trabeculectomy group than in the tube group (p = 0.031). A correlation between the thickness of the bleb wall and inflammation was found (r = 0.56, p < 0.01). EX-PRESS and silicone tube implants appear to be relatively inert, with little difference in biocompatibility and bleb survival. Since some degree of inflammation was still observed histologically in the bleb, more noninvasive surgical methods and more biocompatible materials may be desirable.

Comparison of conjunctival vascularity changes using optical coherence tomography angiography after trabeculectomy and phacotrabeculectomy

AbstractPurposeTo compare the bleb vascularity using optical coherence tomography angiography (OCT‐A) between mitomycin‐C (MMC) augmented trabeculectomy and phacotrabeculectomy and to investigate the relationship between bleb vascularity and surgical outcomes.MethodsWe retrospectively reviewed data for 72 eyes from 72 glaucoma patients who underwent MMC augmented trabeculectomy with/without cataract surgery. Bleb area scans were obtained using OCT‐A during the preoperative period and 1, 2, 4, and 6 weeks, and 2, 4, and 6 months postoperatively. For conjunctival vascularity analysis, a semi‐automated program was used to calculate the densities of color and brightness of the selected area.ResultsColor and brightness densities were decreased in the trabeculectomy group during all periods, whereas it did not decrease in the phacotrabeculectomy group at 4 and 6 weeks, 2, 4, and 6 months. The color and brightness densities were significantly higher in the phacotrabeculectomy group than in the trabeculectomy group after 6 weeks and 2, 4, and 6 months. A Kaplan‐Meier survival graph showed that the intraocular pressure was not different according to surgery type, but glaucoma type. Logistic regression analysis revealed that the brightness density 1 week postoperation was correlated with reoperation.ConclusionsFollowing trabeculectomy with MMC, The brightness density one week postoperation may be a predictive index for surgical outcomes, suggesting that a more accurate prediction could be made if evaluation of bleb structural analysis and bleb vascularity are performed simultaneously.

Postoperative adjunctive bevacizumab versus placebo in primary trabeculectomy surgery for glaucoma.

To compare the effectiveness of postoperative adjunctive use of subconjunctival bevacizumab in altering the outcome of primary trabeculectomy in terms of sustained lowering of intraocular pressure (IOP) and reduction of postoperative bleb vascularization and fibrosis. A prospective, one center, randomized, placebo-control study. Fifty-nine patients (59 eyes) with uncontrolled IOP under maximal tolerated medical treatment (MTMT) were recruited. A primary trabeculectomy with mitomycin C (MMC) was done and the patients were randomized to either postoperative subconjunctival injection of bevacizumab (1.25 mg/0.05 mL) or balanced salt solution (BSS). Forty-seven patients (47 eyes) completed at least one year of follow up and were included in the study. The main outcome measure was the IOP, and secondary outcome measures include bleb morphology, vascularization, and fibrosis, as well as the need for glaucoma medications and 5-fluorouracil (5-FU) needling. At 1-year follow up, there was no significant difference between groups for IOP (P=0.65), bleb morphology (P=0.65), and the need for glaucoma medications (P=0.65) or 5-FU needling requirements (P=0.11). However, the bevacizumab group had a higher rate of success results, lower use of glaucoma medications after surgery, and optimal bleb aspect in more patients, but more 5-FU needling procedures required. A bigger sample size is needed in order to determine whether the differences found in the bevacizumab group are statistically significant.

Comparison of conjunctival vascularity changes using optical coherence tomography angiography after trabeculectomy and phacotrabeculectomy.

To compare bleb vascularity changes using optical coherence tomography angiography (OCT-A) between mitomycin-C (MMC)-augmented trabeculectomy and phacotrabeculectomy and to determine whether bleb vascularity measurements during preoperative and early postoperative periods could act as surrogate parameters to predict surgical outcomes. We retrospectively reviewed data for 72 eyes from 72 glaucoma patients who underwent MMC-augmented trabeculectomy with/without cataract surgery. Bleb area scans were obtained using OCT-A during the preoperative period; 1, 2, 4, and 6weeks postoperatively; and 2, 4, and 6months postoperatively. For conjunctival vascularity analysis, a semi-automated program was used to calculate color and brightness densities of the selected area. Color and brightness densities were decreased in the trabeculectomy group during all periods but not in the phacotrabeculectomy group at 4 and 6weeks, as well as 2, 4, and 6months postoperatively. Color and brightness densities were significantly higher in the phacotrabeculectomy group than in the trabeculectomy group after 6weeks and 2, 4, and 6months postoperatively. A Kaplan-Meier survival graph indicated that intraocular pressure differed according to glaucoma type but not surgery type. Logistic regression analysis revealed that brightness density 1week postoperatively was correlated with reoperation. Changes in conjunctival vascularity density measured by OCT-A differed according to the surgical method. Following trabeculectomy with MMC, brightness density 1week postoperatively may be a predictive index for surgical outcomes.

Effect of 2 Novel Sustained-release Drug Release Systems on Bleb Fibrosis: An In Vivo Trabeculectomy Study in a Rabbit Model.

Rabbit model studies suggested better morphology blebs with equal intraocular pressure (IOP) efficacy as a standard mitomycin C (MMC) trabeculectomy using a novel slow-release drug delivery antifibrotic system delivering small quantities of MMC and 5-fluorouracil (5-FU). To evaluate 2 different concentrations of biodegradable poly(lactic-co-glycolic acid) (PLGA) system with 5-FU and MMC (ElutiGLASS) for their ability to reduce fibrosis and compare the results with standard trabeculectomy with MMC in a rabbit model. New Zealand albino rabbits (19) were divided into 3 groups (A, B, C) and standard trabeculectomy operation was performed in the right eye of each rabbit.Group (A) had trabeculectomy with MMC (0.4 mg/mL) applied using a Weck cell sponge; (B) trabeculectomy with slow-release ElutiGLASS (0.23 mg, 5-FU/0.33 μg MMC released over 23 to 30 d); (C) trabeculectomy with rapid release ElutiGLASS (0.45 mg of 5-FU/0.65 μg MMC, released over 5 to 7 d). The rabbits were followed for 3 months before euthanasia. Bleb morphology, vascularity, and fibrosis were less pronounced in groups B and C when compared with group A at 3 months. Group B appears to have a lower and more diffuse bleb appearance compared with the other 2 groups with honeycomb appearance on both clinical examination and ultrasound biomicroscopy imaging with higher percentage of maintained bleb space (83%), less fibrosis than group A while maintaining the same low inflammation score as the other 2 groups on histology. At 3 months, the PLGA polymer had completely disappeared in all rabbits. There were no statistical differences in the degree of IOP reduction or histologic inflammation, among the 3 groups. We successfully created a sustained-release antifibrotic drug delivery system that delivered known dosage of the drugs at doses that are significantly lower than the current standard, and resulted in less fibrosis while maintaining a healthy bleb and equal reduction of IOP. These results are supportive of the antifibrotic effect of the slow-release drug delivery system used in conjunction with trabeculectomy, thus paving the way for human pilot studies to improve and simplify existing surgical techniques for filtering surgeries in glaucoma.

Evaluation of Functional Filtering Bleb Using Optical Coherence Tomography Angiography.

PurposeThis study investigated whether filtering blebs can be evaluated using optical coherence tomography angiography (OCT-A) and compared vascularity parameters with conventional bleb grading systems.MethodsA total of 92 patients with glaucoma, who underwent mitomycin C–augmented trabeculectomy, were enrolled in this study, and 92 eyes were assessed in total. The participants underwent OCT-A in external mode and anterior segment photography for bleb evaluation. For evaluation of bleb vascularity, a blinded observer carefully drew the bleb area on the original OCT-A image using a semiautomated program that calculated the color and brightness densities of the selected area. A blinded observer also classified the grades of the bleb vessels using the Indiana Bleb Appearance Grading Scale (IBAGS) and Moorfields Bleb Grading System (MBGS). The vascularity parameters using OCT-A were compared with the IBAGS and MBGS results. In addition, the correlation between intraocular pressure (IOP) and the bleb vascularity parameters was assessed.ResultsVessel density measured by OCT-A demonstrated excellent inter- and intraobserver reproducibility. The color and brightness densities were positively correlated with the IBAGS and MBGS vascularity scores. There was no difference in accuracy when predicting IOP risk using vascularity scores from the IBAGS and MBGS or when estimating IOP risk using the color and brightness densities on the net reclassification index.ConclusionsBleb evaluation using OCT-A can evaluate vessel vascularity and showed correlation to the IBAGS and MBGS vascularity grading.Translational RelevanceBleb vascularity measurements using OCT-A could potentially provide objective and quantitative vessel parameters for bleb evaluation following trabeculectomy.

Tear film stability after trabeculectomy and its relationship with bleb morphology

Objective: To investigate the tear film stability after trabeculectomy and its relationship with bleb morphology using Optical Quality Analysis System Ⅱ (OQAS Ⅱ). Methods: A cross-sectional study. Glaucoma patients undergoing trabeculectomy in the Eye Hospital of Wenzhou Medical University from November 2011 to November 2016 were invited by telephone to perform optical quality, bleb photography, and break-up time examinations, and history of surgeries and medications was collected. Bleb morphology was graded according to the Indiana bleb appearance grading scale. The tear film stability was the average objective scatter index value measured using OQAS Ⅱ for 10 seconds after blinking minus the baseline objective scatter index. The higher the tear film stability value, the worse the stability. The difference in the tear film stability between the surgical eyes and non-surgical eyes was compared by the Mann-Whitney U test, and the relationships between the optical quality, bleb height, extent and vascularity were compared by the Kruskal-Wallis H test. Results: Sixty-three patients (76 eyes) were enrolled in the study, including 55 surgical eyes and 21 non-surgical eyes. The mean follow-up time was (39.6±26.2) months.In the surgical and non-surgical eyes, the M(Q(R)) of tear film stability was 0.46 (0.86) and 0.23 (0.41), respectively. The tear film stability in the surgical eyes was reduced compared to the non-surgical eyes (P=0.044). The trabeculectomy group was divided into three subgroups according to the height of the filtering bleb: H0 (17 eyes), H1 (24 eyes) and H2-3 (14 eyes). The M(Q(R)) of tear film stability in the three subgroups was 0.40(0.68), 0.70(1.02) and 0.40(1.24), respectively, with no statistically significant difference detected (P=0.481). According to the bleb extent, the surgical group was divided into two subgroups: E0-1 (36 eyes) and E2-3 (19 eyes). The M(Q(R)) of optical quality in the two subgroups was 0.63 (0.78) and 0.26(1.17), respectively, with no significant difference detected (P=0.261). According to the degree of bleb vascularity, the surgical group was divided into three subgroups: V0 (25 eyes), V1 (14 eyes), and V2-3 (16 eyes). The M(Q(R)) of optical quality in the three subgroups was 0.39 (0.69), 0.55 (1.18) and 0.63 (1.24), respectively, with no significant difference (P=0.401). Conclusion: Although tear film stability decrease after trabeculectomy, the decrease is not associated with the bleb morphology. (Chin J Ophthalmol, 2019, 55:214-219).

Relationship between filtering bleb vascularization and surgical outcomes after trabeculectomy: an optical coherence tomography angiography study.

To explore the relationship between the bleb vasculature and surgical outcome after trabeculectomy (TRAB) using optical coherence tomography angiography (OCT-A). A prospective study was conducted, which included 26 eyes of 26 primary glaucoma patients in the final analysis. Thereinto, six patients underwent TRAB combined 5-FU and 12 patients received subconjunctival 5-FU injection postoperation. The bleb vessel was evaluated using OCT-A 1week, 2weeks, 1month, 3months, and 6months after TRAB. Intraocular pressure (IOP), filtering bleb height, and bleb wall thickness were recorded at the same time. Pearson's correlation analysis and linear regression analysis were performed to determine the correlation of the vessel area data with other parameters. Compared with vessel area 1week after surgery, there was significant increase of the vessel area (△vessel area) 2weeks (11.13 ± 11.91%, p < 0.05) and 1month (16.91 ± 14.85%, p < 0.0001) after surgery in all patients. The △vessel area was significantly greater in acute angle closure (AAC) and primary angle closure glaucoma (PACG) 1-month post-TRAB as compared with that 1week (p < 0.05). The results indicated that the △vessel area 1-month post-TRAB was positive correlated with IOP 6-month post-TRAB (β = 3.88, p = 0.042). Filtering bleb vascularization evaluation using OCT-A could potentially predict IOP 6-month post-TRAB. Surgery effect predicted by filtering bleb vascularization detection is conducive to the select specific postoperative intervention to improve the success rate of TRAB.

Healing modulation in glaucoma surgery after application of subconjunctival triamcinolone acetate alone or combined with mitomycin C: an experimetal study.

to study the efficacy and safety of the use of subconjunctival triamcinolone acetate alone or in combination with mitomycin C as a modulator of trabeculectomy healing in rabbits. we submitted thirty male, albino, New Zealand rabbits to bilateral trabeculectomy. We divided the animals into four experimental groups with 15 eyes per group: control, mitomycin C, triamcinolone acetate and triamcinolone acetate + mitomycin C. We performed aplanation tonometry and clinical analysis of the bleb through the Moorfields Graduation System in the postoperative period. For the evaluation of healing, we carried out the quantitative analysis of the inflammatory infiltrate (polymorphonuclear) through Hematoxylin & Eosin staining, and vascular proliferation, through immunohistochemistry. we observed a significant decrease in postoperative intraocular pressure in all groups compared with the preoperative pressure (p<0.001). However, there was no difference between groups (p=0.186). The triamcinolone + mitomycin C acetate group presented better indices as for the maximum bleb height and vascularization of the bleb central area (p=0.001); in addition, there was a lower inflammatory response (p=0.001) and lower vascular proliferation (p=0.001) in the intermediate phase of the study compared with the monotherapies. the combination of mitomycin C and triamcinolone acetate resulted in a synergistic action between these agents, with broader and more diffuse blebs, less inflammatory infiltrate and less vascular proliferation in the intermediate stages of follow-up in this animal model.

Five Years' Outcomes of Trabeculectomy with Cross-linked Sodium Hyaluronate Gel Implantation for Chinese Glaucoma Patients.

Background:Trabeculectomy is the most efficient surgical treatment. Prevention failure of bleb cicatrix would lead to unsatisfactory postoperative intraocular pressure (IOP) controlling and unsatisfactory success rate. The aim of this study was to evaluate the 5-year outcomes of trabeculectomy with a cross-linked sodium hyaluronate gel implantation for Chinese glaucoma patients.Methods:This is a prospective, case-controlled study. Patients who were to be applied first-time trabeculectomy in the Department of Ophthalmology of Peking University Third Hospital between 2010 and 2012 were included in the study. Totally, 60 eyes were randomly assigned to the trabeculectomy group (TA group) or the trabeculectomy with cross-linked sodium hyaluronate gel implantation group (TH group). Follow-up was finished at 1 week, 1 month, 3 months, 1 year, 3 years, and 5 years after the operation. The statistical index of demographic data, IOP, bleb shape, and any complications or medications or surgical procedures were recorded and assessed by SPSS 19.0 software through independent t-test, one-way analysis of variance (ANOVA) and Pearson's Chi-square test, respectively.Results:The baseline IOP was comparable between the two groups (t= −1.00, P= 0.32) while the postoperative IOP was significantly lower in the TH group at 1, 3 and 5 years' time points (P = 0.00, P= 0.01 and P = 0.01, respectively). According to the Indiana Bleb Appearance Grading Scale, the height and extent of bleb were better in the TH group at all follow-up time points (P < 0.05), however, the comparison of bleb vascularity showed no statistical difference (P > 0.05). TA group had a higher percentage of complications (13% vs. 3%) compared to TH group; however, there was no statistical difference in the comparison of each statistical item (P > 0.05, respectively). The complete success at 5 years was higher in the TH group than that in the TA group (78% vs. 54%, P = 0.03).Conclusion:Our results suggested that implantation of cross-linked sodium hyaluronate gel with trabeculectomy was more efficient and would improve the prognosis of glaucoma patients.