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Introduction In the early postoperative period following trabeculectomy, monitoring the journey of bleb formation is crucial for assessing surgical success. Anterior-segment optical coherence tomography (AS-OCT) emerges as a powerful tool in this pursuit, offering high-resolution imaging of bleb morphology and dynamics. This study aims to evaluate the internal structure of blebs through their maturation phases using AS-OCT. Methods Fifty-five eyes undergoing trabeculectomy were enrolled in a prospective observational study. Serial AS-OCT examinations were done on day 1, week 1, week 3, and week 6 postoperatively; bleb parameters were calculated and correlated with intraocular pressure (IOP). Results IOP control was seen in 45 eyes six months of post-trabeculectomy. Multiform bleb wall reflectivity (BWR) statistically correlates with the success of trabeculectomy. Blebs were successful if BWR showed no change from day 1 to week 6. BWR remained the same on all follow-ups if week 1 bleb wall thickness (BWT) was less than 129.5 microns with 82.6% sensitivity and 83.3% specificity. The cumulative hazard of change in BWR is estimated to be approximately 5.6%, 15.7%, and 17.9% at week 1, week 3, and week 6 follow-ups, respectively. Conclusions Successful blebs showed consistent BWR from day 1 to week 6 of follow-up. Serial AS-OCT examination for changes in BWR in early stages can be done to predict the fate of bleb. The maximum change in BWR occurs between the week 1 and week 3 follow-up periods requiring close follow-up.

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Trabeculectomy has traditionally been upheld as the gold standard in glaucoma surgery, but recent advancements, including the PRESERFLO® MicroShunt, have introduced less invasive techniques to mitigate complications and reduce intraocular pressure (IOP). The examination of bleb morphology post-filtering surgery is critical for modulating wound healing and ensuring long-term success. While previous evaluations of PRESERFLO-generated blebs have relied on data from trabeculectomy blebs, the differing surgical techniques used in PRESERFLO and trabeculectomy surgeries suggest potential variations in bleb morphologies. This study conducted a comparative analysis of blebs resulting from PRESERFLO and trabeculectomy procedures. Retrospective descriptive assessments using the Jenaer Bleb Grading System were performed, along with quantitative evaluation using eight-dimensional parameters utilizing anterior segment OCT. We included 93 eyes (57 following PRESERFLO, 36 following trabeculectomy). In the descriptive assessment, PRESERFLO-generated blebs exhibited fewer conjunctival cysts (3.5% vs. 22.2%, p = 0.007) and cavernous changes (10.5% vs. 30.5%, p = 0.021) compared to trabeculectomy. Quantitatively, overall bleb dimensions were comparable (maximal bleb height, width, and length, p > 0.05 for all). However, PRESERFLO blebs displayed a shallower (0.52 ± 0.24 vs. 0.67 ± 0.3 mm, p = 0.017) yet longer (4.12 ± 1.54 vs. 3.23 ± 1.64 mm, p = 0.024) episcleral lake. A thicker bleb wall (1.52 ± 0.46 vs. 1.10 ± 0.37 mm, p < 0.001) along with more posteriorly positioned blebs (distance to limbus = 6.16 ± 1.36 vs. 4.87 ± 1.34 mm, p < 0.001) were observed following PRESERFLO. This study illuminates the nuanced morphological differences between PRESERFLO and trabeculectomy blebs. Understanding these distinctions is vital, empowering clinicians to make informed postoperative decisions and avoid misinterpretation of bleb morphology.

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We investigated the internal morphology of filtration blebs after XEN gel stent implantation using anterior segment optical coherence tomography (AS-OCT) and identified factors related to intraocular pressure (IOP) postoperatively. Eighteen eyes of 18 patients who had undergone XEN gel stent implantation were analyzed. Blebs were imaged using Visante OCT (Carl Zeiss Meditec AG, Germany) at 6 months and 1 year after surgery and evaluated for quantitative parameters including bleb height, maximum height of internal cavity, maximum bleb wall thickness, and maximum bleb epithelial thickness. Subjects were classified into two groups according to the presence or absence of a definite internal cavity between the conjunctiva and sclera using AS-OCT imaging. Nine eyes (50%) were assigned to the internal cavity group and 9 (50%) to the uniform group. Postoperative IOP was significantly lower in the internal cavity group than in the uniform group both at 6 months and 1 year after surgery (p = 0.024 and p = 0.040). Postoperative IOP showed statistically significant negative correlations with bleb height and the height of the internal cavity (Spearman correlation coefficient r = -0.518, p = 0.028 and r = -0.453, p = 0.034, respectively). AS-OCT facilitates analysis of bleb morphology after XEN gel stent implantation. A larger height of the internal cavity of the bleb appeared to correlate with lower IOP after XEN implantation.

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AIM: To evaluate the safety and efficacy of posterior scleral application (a modified technique) of an antimetabolite mitomycin C-soaked sponge in trabeculectomy for patients with glaucoma. METHODS: This retrospective study included 101 patients (115 eyes) with glaucoma (aged 12-83y) who underwent trabeculectomy using a modified mitomycin C-soaked sponge placement method. A piece of 3.5×10 mm2 sponge was placed vertically and posteriorly with the long side perpendicular to the limbus. The mitomycin C concentration and exposure time were 0.2-0.5 mg/mL and 1-5min, respectively. Intraocular pressure, best-corrected visual acuity, and hypotensive medications were recorded at baseline and at the final visit. Complications, interventions required, and bleb morphology were recorded postoperatively. The primary outcome was trabeculectomy safety, including complications and bleb morphology; the secondary outcome was the trabeculectomy success rate. RESULTS: At the final follow-up [median 28mo, range 7-67mo and interquartile range (IQR) 13mo], the qualified (cumulative) success rate was 93.0% and the complete success rate was 60.0%. No bleb-related complications were observed. The mean height, extent, and vascularity grades were 0.6±0.9, 1.1±0.4, and 2.4±0.9, respectively. All Seidel tests were negative. The mean posteriority grade was 0.8±0.4. CONCLUSION: Trabeculectomy with the long side of a mitomycin C-soaked sponge placed perpendicular to the corneal limbus is safe and effective.

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Evaluation of bleb morphology is a vital part of successful filtration glaucoma surgery. The PRESERFLO-MicroShunt (PRESERFLO) and XEN-Gel-Stent (XEN) are drainage devices implanted using different surgical approaches (ab externo and ab interno, respectively), potentially resulting in distinct bleb morphology. Understanding these morphological differences is essential for postoperative care. In this study, we retrospectively examined functioning blebs following PRESERFLO and XEN implantation using high-resolution anterior segment OCT imaging. Qualitative assessment utilizing the Jenaer Bleb Grading System and quantitative assessment measuring 12 parameters representing bleb dimensions were conducted, and the results were compared between the two groups. A total of 80 eyes from 80 patients were included (41 after PRESERFLO, 39 after XEN). Functioning blebs following PRESERFLO exhibited a higher frequency of hyperreflective tenon changes compared to XEN (31.7% vs. 10.3%, respectively, p = 0.02) and a lower frequency of cavernous changes (17.1% vs. 35.9%, p = 0.05). Additionally, PRESERFLO blebs showed a higher frequency of visible episcleral lakes (92.7% vs. 30.8%, p < 0.001). Furthermore, PRESERFLO blebs demonstrated larger height (2.13 ± 0.5 vs. 1.85 ± 0.6 mm, p = 0.03), width (10.31 ± 2.3 vs. 9.1 ± 2.3 mm, p = 0.02), length (9.13 ± 1.8 vs. 8.24 ± 1.9 mm, p = 0.04), posterior location relative to the limbus (6.21 ± 1.2 vs. 5.21 ± 1.8 mm, p = 0.005), and a thicker bleb wall (1.60 ± 0.5 vs. 1.1 ± 0.4 mm, p = 0.004). Functioning blebs following PRESERFLO and XEN displayed morphological distinctions, likely attributed to variations in surgical techniques (ab externo vs. ab interno) and stent dimensions. These morphological differences should be taken into consideration when evaluating blebs, as they could impact assessments of bleb functionality and influence decisions regarding postoperative interventions.

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PURPOSE: To investigate potential risk factors, particularly antimetabolite choice, with regard to the development of adverse bleb morphology in eyes that had undergone trabeculectomy surgery. METHODS: A single-centre, observational cohort study of 631 consecutive eyes, which had undergone trabeculectomy over an 11-year period. For each case, bleb morphology was recorded at 2 years, and its association with the per-operative antimetabolite as well as potential confounding risk factors was analysed using univariate (unadjusted) and multivariate (adjusted) logistical regression analyses to identify those that could contribute to the development of adverse blebs. A standard protocol for 5-fluorouracil and mitomycin-C utilization was employed in the majority of cases. RESULTS: When 5-fluorouracil was used (n = 257), 24% of patients formed cystic or partially cystic blebs, whereas with mitomycin-C (n = 299), only 12% formed such adverse blebs, the difference being statistically significant (OR = 3.54, p = 0.002 unadjusted; OR = 7.49, p = 0.00 adjusted). Of the other potential confounding factors, care within the private sector (OR = 0.30 p = 0.02) and a history of previous ocular surgery involving a conjunctival incision were identified as potential risk factors for the formation of adverse cystic blebs (OR = 0.28, p = 0.02). CONCLUSIONS: Modern use of mitomycin-C appeared to be better than 5-fluorouracil as an adjunctive antimetabolite used at the time of trabeculectomy, with respect to the development of preferable final bleb morphology. The only potential preoperative risk factors found to be significant with respect to adverse cystic bleb development were care in the private health sector and previous ocular surgery involving a conjunctival incision.

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Background: The purpose of this study is to compare the morphology of six-month follow-up blebs created by a subconjunctival glaucoma surgical device (XEN45) to those created by a PreserFlo MicroShunt with a sub-Tenon insertion, utilizing AS-OCT. Methods: A retrospective study of 29 eyes who underwent XEN45 implantation and 29 eyes who underwent PreserFlo MicroShunt implantation. The patients were analyzed at 24 h, 1 week, 1 month, 3 months and 6 months. At each visit, the maturation and morphological alterations of the blebs were observed, as well as connections with the IOP. Results: In both groups, IOP showed significant reduction at all follow ups (p < 0.0001). In XEN group, the most common bleb morphology in the immediate postoperative was the subconjuntival separation type (42%) followed by the uniform type (34%), with a trend inversion at 6 month follow up (51% of uniform type). On the contrary, the most common morphology after PreserFlo was the multiple internal layer (55%), which showed a tendency to reduce over time and was substituted by the microcystic multiform, whose percentage increased over time (17% at day 1 vs. 44% at month 6). Uniform appearance was associated by the posterior episcleral fluid (PEF) lake presence. Both horizontal and vertical diameters significantly increased over time. Conclusion: XEN and PreserFlo implantation resulted in the production of diffuse blebs with different characteristics, which may influence IOP lowering capacity and bleb revisions necessity over time.

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Purpose: To comparatively evaluate in Indian eyes with coexisting cataract and primary open-angle glaucoma the outcome of mitomycin C (MMC) and Ologen implant as adjunctives in combined phacoemulsification with trabeculectomy. Methods: Eyes with primary open-angle glaucoma that underwent trabeculectomy and phacoemulsification with IOL implantation with either MMC application or Ologen implant between June 2019 and February 2020 were followed up for 12 months. Thirty-four eyes of 34 participants were studied. The primary outcome was intraocular pressure (IOP), and the secondary outcomes were the number of ocular hypotensives, best distance visual acuity (BDVA), and bleb morphology. Results: In 16 eyes treated with MMC and 18 eyes treated with Ologen implant, it was observed that the mean postoperative IOP (14.62 ± 2.89 mm Hg with MMC and 14.56 ± 4.14 mm Hg with Ologen implant) was not significantly different in both groups (P = 0.47). Number of ocular hypotensives and BDVA were also comparable between the two groups. However, bleb morphology was better with Ologen implantation. One eye in the MMC group developed hypotony which was conservatively managed. Conclusion: MMC and Ologen are both effective adjunctives in combined phaco-trabeculectomy. However, the Ologen implant provides better bleb health and safety.

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The formation of filtration blebs is the main drainage mechanism for reducing intraocular pressure after traditional incisional glaucoma surgery such as trabeculectomy and non-penetrating deep sclerotomy. Early and short-lasting blebs may also occur after canaloplasty. Bleb formation also plays an important role after the implantation of glaucoma drainage devices, including Minimally Invasive Glaucoma Surgery devices. Anterior segment optical coherence tomography (AS-OCT) is a rapid and non-invasive high-resolution imaging technique that has evolved in recent years to become a routine examination. Anterior segment optical coherence tomography (AS-OCT) provides key information in the assessment and follow-up of glaucoma surgery, especially in the assessment of filtration blebs. Thus, bleb morphology can be qualitatively classified into diffuse, cystic, encapsulated and flattened, and AS-OCT imaging can also provide several quantitative parameters of the bleb, such as total bleb height, bleb fluid-filled cavity height, bleb wall thickness, number of microcysts and trabeculectomy opening size. These parameters could have an impact on clinical management during follow-up because they may predict the success or failure of the surgery in the early and late postoperative periods. Additionally, they may also guide the procedures used to increase filtration and reduce intraocular pressure, such as bleb needling and laser suture lysis.

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OBJECTIVE: To 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. METHODS: This 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. RESULTS: There 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). CONCLUSION: The 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.

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PURPOSE: To track changes in the morphology of hyperemic blebs in eyes undergone trabeculectomy with mitomycin C 0.02% (MMC) after triamcinolone acetonide (TA) injection. METHODS: 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) 1 week, 1 month, 3 months, 6 months, and 1 year 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 6 mmHg, and loss of Light Perception (LP) vision. RESULTS: 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 ± 2.57 weeks. 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. CONCLUSION: Injection of TA in hyperemic failing blebs improves bleb morphology by decreasing vascularity and height while increasing the extent with an acceptable safety profile.

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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).

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PURPOSE: To report long-term safety and efficacy of trabeculectomy with collagen implant in Indian population. METHODS: All cases of trabeculectomy with Ologen® Collagen Matrix implant performed over a 7-year period from May 2008 through April 2015 at a tertiary referral institute were reviewed. A total of 30 eyes of 28 patients were included in the study with two patients undergoing bilateral trabeculectomy. Outcomes measured included intraocular pressure (IOP) control, number of antiglaucoma medications used, bleb morphology, and complications/reoperations. RESULTS: Trabeculectomy resulted in reduction in IOP from 36.46 to 11.65 mm Hg in the immediate postoperative period (day 1), a 68% decrease to 15.18 mm Hg at 84 months (58% decrease). The mean IOP reduction decreased over time from 63% in the first year to 55% after 5 years of follow-up. Fourteen eyes attained a follow-up of 5 years and eight eyes a follow-up of ≥7 years. No sight-threatening complication such as hypotony, bleb leak, and bleb-related endophthalmitis was observed in our series, and only intervention required was 5-fluorouracil needling in one case. CONCLUSION: Ologen-augmented trabeculectomy is effective in controlling IOP over a long-term follow up from minimal 3 to maximal 7 years. No untoward events jeopardizing bleb safety were noted at any time. This modality is a viable alternative for patients with contraindications to use of antimetabolites.

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PURPOSE: To evaluate the efficacy of autologous anterior lens capsule (ALC) in phacotrabeculectomy. MATERIAL AND METHODS: In this prospective, randomized case control study, after obtaining institutional ethical clearance and informed consent, 88 eyes posted for phacotrabeculectomy were divided into ALC and non-ALC groups. Combined phacoemulsification, with posterior chamber intraocular lens implantation and trabeculectomy, was performed in both groups. Anterior lens capsule transplantation was done in the first group beneath the sclera flap. Follow-up of three months was carried out and the morphology of bleb, intraocular pressure (IOP), requirement for additional medications, and complications were compared between the two groups. RESULT: Statistical difference favoring the ALC group was seen in IOP reduction (p < 0.05) at each follow-up, qualified success rate and failure rate at the three-month follow-up (p = 0.006), but no difference in bleb morphology was seen. CONCLUSION: ALC implantation is beneficial in maintaining filtration in a combined surgery with minimal complications.

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OBJECTIVE: To provide a qualitative analysis of filtering blebs after being surgically repaired due to late blebs leaks. METHODS: Blebs were studied 6 months after surgical reparation using AS-OCT Triton (Topcon®). An analysis was made of the morphological pattern and internal structures of blebs, including the covering, in 10 patients. The images were obtained using OCTs at a wavelength of 1050nm. RESULTS: According to the Hirooka classification, three different patterns were found in the structure of blebs, which made it possible to correlate them with their functionality. A full covering was observed in 70% of the cases, and they showed sub-epithelial cysts (cystoid pattern). Two cases showed a full conjunctival retraction without Tenon's covering. The walls were thin, with a de-structured bleb (diffuse pattern) being visualised. In the third group, the image showed a partial conjunctival retraction with Tenon's covering. There were some sub-epithelial diffuse cysts with walls following a laminar pattern. CONCLUSION: Using AS-OCT, it is possible to study the bleb's characteristics in detail, as well as the cover, in the case of blebs requiring repair due to late leaks, using conjunctival advancement. It allows for the early visualisation of conjunctival retractions that were not visible in a slit lamp, and to predict the functionality of the blebs by their morphology.

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Background: Our aim was to determine the predictive value of postoperative bleb morphological features and intraocular pressure (IOP) on the success rate of trabeculectomy. Methods: In this prospective interventional case series, we analyzed for one year 80 consecutive primary open angle glaucoma patients who underwent mitomycin-augmented trabeculectomy. Bleb morphology was scored using the Indiana bleb appearance grading scale (IBAGS). Success was defined as IOP ≤15 mmHg with or without medications at 12 months. We tested for IOP and bleb morphological differences between groups, applied a multivariable regression analysis and determined the area under the receiver operating characteristic curve (AUC). Results: Age and gender were equally distributed (62.3±13.1 years, P=0.911). IOP of patients with a successful outcome did not differ from unsuccessful ones on day 1, 7 and 30 (all P≥0.2). The AUC of IOP at day 1, day 7 and 30 for predicting a successful outcome was 0.355, 0.452, and 0.80, respectively. The AUC for bleb morphology parameters, bleb height, extension, and vascularization, on day 14 were 0.368, 0.408, and 0.549, respectively. Values for day 30 were 0.428, 0.563, and 0.654. IOP change from day 1 to day 30 was a good predictor of failure (AUC=0.838, 95% CI: 0.704 to 0.971) with a change of more than 3 mmHg predicting failure with a sensitivity of 82.5% (95% CI: 68 to 91%) and a specificity of 87.5% (95% CI: 53 to 98%). Conclusions: The postoperative IOP on day 30 had a fair to good accuracy while the bleb features failed to predict a successful outcome. An IOP increase by as little as more than 3 mmHg during the first 30 days was a good predictor of failure.

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PURPOSE: The aim of this study was to assess bleb function using Wuerzburg bleb classification score (WBCS) for bleb morphology on slit lamp, intraocular pressure (IOP), and gonioscopy. METHODS: A total of randomly selected 30 eyes posttrabeculectomy were assessed for bleb function with the trio of bleb morphology, IOP, and gonioscopy. Bleb was assessed using the WBCS of 0-12 on slit lamp, IOP was assessed using applanation tonometry, and visualization of inner ostium and iridectomy were assessed using gonioscopy. Postoperative patients of less than six weeks were excluded from the study. RESULTS: The correlation between WBCS and the duration of trabeculectomy was found to be highly significant (P value = 0.029). The correlation of IOP with WBCS was also found to be strongly positive (P = 0.000). IOP was found to be highly associated with peripheral iridectomy (P = 0.000), internal window (P = 0.001), and bleb characteristics.

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PURPOSE: To verify, by use of data collected by the Japan Glaucoma Society Survey of Bleb-related Infection (JGSSBI), that bleb morphology changes within 12 months of the development of bleb-related infection. METHODS: JGSSBI data from 57 eyes of 57 patients with primary open-angle glaucoma and normal tension glaucoma who developed a bleb-related infection were analyzed. Morphological features of the blebs were graded by use of a predetermined grading system. Multiple logistic regression analysis was conducted to identify factors relating to bleb morphology which were associated with poor outcome. RESULTS: Bleb sizes, including both circumferential and tangential lengths, were significantly smaller for stage IIIa/IIIb infections than for stage I/II bleb infections (P = 0.009 and P = 0.026 for the circumferential and tangential lengths, respectively; Fisher's direct probability test). The bleb wall also became significantly thicker during stage IIIa/IIIb infections (P = 0.003). After infection, intraocular pressure (IOP) increased significantly for all cases but was no different in the three subgroups (i.e. stage I, stage II, and stage IIIa/IIIb bleb infections). Multiple logistic regression analysis revealed that a stage III infection was significantly associated with a poor outcome for the bleb. CONCLUSIONS: This study revealed that the filtering bleb became smaller, both tangentially and circumferentially, and thicker, after stage III infections than after stage I or II infections.

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PURPOSE: To determine the morphometric parameters of filtration blebs of a valved aqueous humor drainage device. MATERIALS AND METHODS: Orbital magnetic resonances imaging (MRI) was taken after implantation of an Ahmed valve (FP7 model). Outcomes of the analysis were intraocular pressure (IOP) and the bleb's morphometric analysis (volume, height, major and minor axis). Associations between IOP and the imaging-related study variables were explored by Spearman's correlation test. RESULTS: Eleven patients underwent orbital MRI examination. Recordings were taken after a mean of 2.7 months (1-6 months) after surgery. IOP was significantly lower than its preoperative values (17.6 ± 6.4 mm Hg vs 36.1 ± 6.4 mm Hg, p < 0.01). Mean bleb volume was 856.9 ± 261 mm(3) and its height, major and minor axis were 5.77 ± 1.9, 14.8 ± 2.9 and 8.14 ± 3.6 mm, respectively. A positive correlation was detected between IOP and mean height (r = 0.77, p = 0.048) and major axis (r = 0.83, p = 0.03). Interestingly, the overall bleb volume was related to IOP levels immediately prior to surgery (r = 0.75, p < 0.01). Additionally, the posterior part of the plate was found to be displaced from the scleral surface in five cases (45%). CONCLUSION: Ahmed valve's bleb morphology seems to correlate with both the pre- and postoperative IOP, which might suggest a clinical benefit of administering aqueous suppressants pre- as well as postoperatively. The plate of the device may show a significant dislocation from its initial surgical implantation site. How to cite this article: Ferreira J, Fernandes F, Patricio M, Brás A, Rios C, Stalmans I, Pinto LA. Magnetic Resonance Imaging Study on Blebs Morphology of Ahmed Valves. J Curr Glaucoma Pract 2015;9(1):1-5.

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PURPOSE: To investigate the correlation between bleb morphology and IOP control via the modified Indiana Bleb Appearance Grading Scale (IBAGS) and anterior-segment optical coherence tomography (AS-OCT) in two different trabeculectomy (TLE) groups. METHODS: This study involved 94 eyes with primary open angle glaucoma that underwent two different TLE methods: limbal-based TLE (group I, 62 eyes) and fornix-based TLE (group II, 32). IOP control was defined as successful with an IOP ≤ 20 mm Hg and ≥20% reduction of preoperative IOP. IBAGS and various parameters of the bleb height, extent, wall thickness, ciliochoroidal detachment (CCD), and lake under the scleral flap (LUSF) were obtained by slit-lamp and AS-OCT, respectively. Correlation between IOP control and IBAGS/AS-OCT parameters were assessed by SAS. RESULTS: Both groups had the same success rate. As to correlation between IOP control and IBAGS, extent and Seidel were the best-paired parameters in group I (Cp = 3.0402, R = 0.6401), yet no parameter was significant in group II (maximum R = 0.1599). As to correlation between IOP control and AS-OCT, the combinations of height, extent, and the minimum value of bleb wall thickness were significant (Cp = 0.2037, 0.2314, R = 0.4336, 0.4330) in group I. In group II, no parameter was significant, except CCD and/or LUSF (P = 0.032). As to coincidence of IBAGS and AS-OCT parameters, height and extent in group I (P = 0.000, P = 0.000) and height in group II were statistically significant (P = 0.020). CONCLUSIONS: IOP control in limbal-based TLE seemed to be more dependent on the large size and thinned-wall bleb than that in fornix-based TLE.

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