Correlation between filtering bleb morphology, expression of inflammatory marker HLA-DR by ocular surface, and outcome of trabeculectomy

Managing the ocular surface after glaucoma filtration surgery: an orphan topic

BACKGROUND

Ocular surface (OS) disorders before glaucoma filtration surgery (GFS) have been considered to play a crucial role influencing the surgical outcome. Conversely, the impact of surgery itself on the OS is almost completely overlooked, though evidence suggest that ocular surface disease (OSD) may be induced in patients by GFS. This review analyzes the determinants involved in the OSD development after GFS, the clinical features and related consequences, the main diagnostic hallmarks, as well as the therapeutic strategies for its management.

METHODS

The PubMed database was utilized for the literature examination. Keywords that were searched included ocular surface disease, glaucoma filtration surgery, filtration bleb, post-surgical management, and quality of life.

RESULTS

After GFS, OSD is promoted by peri- and post-operative factors, such as the filtration bleb (FB) development, combined surgical approach with phacoemulsification, the use of antifibrotic agents and the reintroduction of antiglaucoma medications. This particular form of OSD that present similar clinical features to mild to moderate dry eye, can be named as post-glaucoma surgery-OSD (PGS-OSD). PGS-OSD may negatively affect the FB functionality, thus potentially hindering the disease control, and significantly worsen the patient quality of life (QOL).

CONCLUSIONS

Clinicians are encouraged to routinely include the OS evaluation after GFS and to consider proper management when the occurrence of PGS-OSD worsen the patient's QOL or exert negative effects to the FB functionality. An outline summarizing the main risk factors and the most appropriate therapeutic options to mitigate the PGS-OSD was proposed to support the routine practice.

Ocular surface and glaucoma, a mutual relationship. Practical suggestions for classification and management

The chronic use of glaucoma medications could improve the development of an ocular comorbidity, the glaucoma therapy-related ocular surface disease. This could be related to the exposure of the conjunctiva to preservatives, but also active compounds such as prostaglandin analogues may improve the risk of ocular surface inflammation. Inflammation has a negative impact on tolerability and adherence to eyedrops and to the outcome of filtration surgery as well. A stratification of glaucoma patients based not only on visual field progression but also on glaucoma therapy-related ocular surface disease would be desirable for a strategic management. Early diagnosis, individualized treatment, and safe surgical management should be the hallmarks of glaucoma treatment. One of the main issues for the proper and successful management of patients is the right timing, effectiveness and safety for both medical and surgical treatment options leading to a precision medicine in glaucoma disease as the best modern treatment.

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

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.

Confocal Microscopy and Anterior Segment Optical Coherence Tomography Imaging of the Ocular Surface and Bleb Morphology in Medically and Surgically Treated Glaucoma Patients: A Review

Glaucoma patients often suffer from ocular surface disease (OSD) caused by the chronic administration of topical anti-glaucoma medications, especially in cases of long-term therapy with preserved or multiple drugs. Additionally, glaucoma surgery may determine ocular surface changes related to the formation and location of the filtering bleb, the application of anti-mitotic agents, and the post-operative wound-healing processes within the conjunctiva. Recently, several studies have evaluated the role of advanced diagnostic imaging technologies such as in vivo confocal microscopy (IVCM) and anterior segment-optical coherence tomography (AS-OCT) in detecting microscopic and macroscopic features of glaucoma therapy-related OSD. Their clinical applications are still being explored, with recent particular attention paid to analyzing the effects of new drug formulations and of minimally invasive surgical procedures on the ocular surface status. In this review, we summarize the current knowledge about the main changes of the ocular surface identified at IVCM and AS-OCT in glaucoma patients under medical therapy, or after surgical treatment.

A Retrospective Comparison of Trabeculectomy, Baerveldt Glaucoma Implant, and Microinvasive Glaucoma Surgeries in a Three-Year Follow-Up

Purpose: This retrospective study aimed to evaluate the safety and efficacy of MIGS (Xen® and Cypass®) compared to trabeculectomy and Baerveldt® implants.Patients and Methods: This single-center study included patients from the Ophthalmic Hospital of Turin between January 2015 and 2018.Efficacy was assessed based on the intraocular pressure and the number of medications necessary to control IOP at 1, 3, 6, 12, 24, and 36 months and the potential complications. Complete surgical success was defined as IOP ≤ 21 mmHg, with no medication or additional glaucoma surgery. Qualified success was defined as IOP ≤ 21 mmHg with the reintroduction of topical medications. Our third measure of success was a delta IOP reduction greater than 20% compared to baseline.Results: The delta IOP compared to the baseline was significant at every instance, except in the Xen® implant group. The average IOP distribution at different time points was significant, except at 1 and 12 months. The delta of the medication number compared to the baseline was significant at every instant. All three methods of success were analyzed using a Kaplan-Meier survival curve that identified a significant difference on the success rates of Xen®-trabeculectomy, Xen®-Baerveldt®, and Cypass®-Baerveldt®.Conclusion: MIGS can reduce the number of medication classes, thus increasing patient compliance and reducing topical ocular toxicity and general costs. Trabeculectomy remains the most effective option but still presents a percentage of failures that might increase during follow-up.

Quantitative analysis of functional filtering bleb size using Mask R-CNN

Background

Deep learning has had a large effect on medical fields, including ophthalmology. The goal of this study was to quantitatively analyze the functional filtering bleb size with Mask R-CNN.

Methods

This observational study employed eighty-three images of post-trabeculectomy functional filtering blebs. The images were divided into training and test groups and scored according to the Indiana Bleb Appearance Grading Scale (IBAGS) system. Then, 70 images from the training group were used to train an automatic detection system based on Mask R-CNN and perform a quantitative analysis of the function bleb size. Thirteen images from the test group were used to evaluate the model. During the training process, left and right image-flipping algorithms were used for data augmentation. Finally, the correlation between the functional filtering bleb area and the intraocular pressure (IOP) was analyzed.

Results

The 83 functional filtering blebs have similar morphological features. According to IBAGS, the functional filtering blebs have a high incidence of E1/E2, H1/H2, and V0/V1. Our Mask R-CNN-based model using the selected parameters achieves good results on the training group after a 200-epoch training process. All the Intersection over Union (IoU) scores exceeded 93% on the test group. The Spearman correlation coefficient between the area of functional filtering blebs and the IOP value was −0.757 (P<0.05).

Conclusions

Deep learning is a powerful tool for quantitatively analyzing the functional filtering bleb size. This technique is suitable for use in monitoring post-trabeculectomy filtering blebs in the future.

Association between Active Helicobacter pylori Infection and Glaucoma: A Systematic Review and Meta-Analysis

Background: Glaucoma is the second most common cause of blindness worldwide affecting almost 70 million individuals. Helicobacter pylori (H. pylori) is a widespread pathogen with systematic pathogenicity. This meta-analysis aimed to estimate the contradictory data regarding a potential association between active H. pylori infection and glaucoma. Materials and Methods: A research in MEDLINE/PubMed and Google Scholar was conducted and original studies investigating the relationship between H. pylori infection and glaucoma were included. Analysis was performed with random effects model. The main outcome was the odds ratio (OR) with 95% confidence intervals (CI) of H. pylori infection as a risk factor for glaucoma. A parallel analysis studied the role of active infection as indicated by histology and the titer of anti-H. pylori antibodies. For the anti-H. pylori antibody titers, weighted mean differences (WMD) were estimated between patients and controls. Results: Fifteen studies were included, with 2664 participants (872 patients with glaucoma and 1792 controls), divided into primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) and pseudo-exfoliation glaucoma (PEG). The association between H. pylori infection and overall glaucoma was significant (OR = 2.08, CI 95% 1.48–2.93) with moderate heterogeneity (I² = 61.54%). After stratification by glaucoma subtype, heterogeneity was eliminated in the NTG subgroup. Studies with healthy controls, and controls with anemia yielded very low or no heterogeneity, respectively. Gastric biopsy to document active H. pylori infection yielded the highest OR (5.4, CI: 3.17–9.2, p < 0.001) and null heterogeneity. For anti-H. pylori antibody titers, there was a significant difference in WMD between patients and controls (WMD 15.98 IU/mL; 95% CI: 4.09–27.87; p = 0.008); values were greater in glaucoma patients, with high heterogeneity (I²: 93.8%). Meta-regression analysis showed that mean age had a significant impact on glaucoma (p = 0.037). Conclusions: Active H. pylori infection may be associated with glaucoma with null heterogeneity, as, beyond histology, quantified by anti-H. pylori titers and increases with age.

The ocular surface after successful glaucoma filtration surgery: a clinical, in vivo confocal microscopy, and immune-cytology study

We investigated the ocular surface (OS) system modifications after completely successful glaucoma surgery in thirty-eight patients undergoing trabeculectomy (surgical group), using laser scanning confocal microscopy (LSCM) and impression cytology (IC). Twenty-six medically controlled glaucomatous patients served as controls (medical group). LSCM, IC, and the ocular surface disease index (OSDI) and National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) questionnaires, were performed at baseline and after six months. The main outcomes were: goblet cell density (GCD), limbal dendritic cell density (LDCD), subbasal corneal nerve inhomogeneity (SCNI), Meibomian gland density and inhomogeneity (MGD, MGI), and HLA-DR positivity. There were no significant baseline differences between groups. At the sixth month, the surgical group showed a GCD increase (p < 0.001), and a LDCD, SCNI, MGI, HLA-DR (p < 0.001), OSDI and NEI VFQ-25 scores decrease (p < 0.05). The medical group did not show significant OS modifications, showing LSCM and IC parameters significantly worse compared to the surgical group (p < 0.001). The OSDI score correlated with GCD, MGI, SCNI, LDCD, and HLA-DR (p < 0.001; p < 0.05; p < 0.01). The present study found that the whole OS system objectively improved after completely successful glaucoma filtration surgery. These changes positively affected the OSDI score, but not the NEI VFQ-25 score.

Prognostic factors for trabeculectomy failure in a Cuban population

OBJECTIVE

To identify the prognostic factors for mid-term trabeculectomy failure.

METHOD

A prospective cohort study was conducted on 113 eyes (113 patients) that had undergone a trabeculectomy for primary open or closed angle, pigmentary, or juvenile glaucoma. Surgical failure was defined if intraocular pressure was equal or more than 18mmHg with medication (two or more drops), after 1-4 postoperative years. The relative risk was calculated and a logistic regression analysis was performed.

RESULTS

Previous trabeculectomy, preoperative intraocular pressure ≥ 31mmHg, black race, and advanced glaucoma increased the failure risk by 7.9 times (P=.036), 5.3 times (P=.011) and 4.7 times (P=.028, and P=.027), respectively. The addition of two or more factors increased the risk by 6.4 times (P<.001). It was not affected by age, sex, pre-operative drops, or surgical complication.

CONCLUSIONS

Previous trabeculectomy, pre-operative intraocular pressure ≥ 31mmHg, black race, and advanced glaucoma are prognostic factors for trabeculectomy failure, in decreasing order of their association with surgical failure. The addition of two or more factors increased the risk of failure. In those situations, the use of trans- operative anti-metabolites is suggested.

Needle bleb revision with bevacizumab and mitomycin C compared with mitomycin C alone for failing filtration blebs

PURPOSE

To report the 6-month comparative outcomes and bleb morphology for needle revision with bevacizumab and mitomycin C (MMC) versus MMC alone of failed trabeculectomy and ExPRESS shunt blebs.

METHODS

Patients undergoing bleb needle revision procedures were enrolled in this study. All patients received a subconjunctival injection of 0.1 mL MMC (0.4 mg/mL) mixed with 0.1 mL preservative-free lidocaine (1%) at the beginning of the procedure. The patients were randomized into 2 cohorts assigned to receive either 1.0 mg (0.04 mL of 25 mg/mL) subconjunctival bevacizumab (treatment group) or 0.04 mL of balanced salt solution (control group) injected in an identical manner posterior to the bleb after the bleb needling. Success was defined as ≥20% reduction in intraocular pressure (IOP) without any IOP-lowering medications. Qualified success was defined as ≥20% reduction of IOP with IOP-lowering medications. Failure was defined as IOP>21 mm Hg, IOP reduction <20%, or need for additional surgery. Bleb morphology was classified using the Indiana Bleb Appearance Grading Scale.

RESULTS

Six months postoperatively, in treatment group (n=29), 57% of patients achieved complete success, and 43% failed. In control group (n=29), 41% of patients achieved complete success, 7% achieved qualified success, and 52% failed. The difference in success rates between the 2 groups was not statistically significant (P=0.35). At 6 months, the mean IOP was 11.52 in treatment group and 12.83 in control group (P=0.45); patients in treatment group were on a mean of 0.16 medications as compared with 0.58 medications in control group (P=0.058). For bleb morphology of treatment group compared with control group, the blebs had less vascularity (0.76 vs. 1.20, respectively, on a scale of 0 to 4, P<0.05) and greater extent (2.68 vs. 2.36, on a scale of 0 to 3, P=0.022) in treatment group.

CONCLUSIONS

There was no significant difference between the success rates and IOPs at postoperative month 6 between treatment and control groups. Postoperative blebs in the treatment group were less vascular and had greater extent.

Shallow Anterior Chamber After Trabeculectomy: Risk Reduction by Use of Removable Compression Sutures

PURPOSE

To evaluate the risk of shallow anterior chamber after trabeculectomy with removable compression sutures.

METHODS

A total of 263 eyes affected by primary open-angle glaucoma that was unresponsive to medical treatments were divided into 2 groups: 126 eyes were treated with conventional trabeculectomy (group A) and 137 with a modified surgery technique using 3 removable compression 10-0 nylon sutures (group B). All the participants received intraoperative antimetabolites (mitomycin 0.04%). Increased intraocular pressure (IOP) of >14 mm Hg in the eyes of group B patients was followed by removal of compression sutures. Best corrected visual acuity, slit lamp examination, IOP, and anterior chamber depth were evaluated 1, 7, 30, 60, 90, and 180 days after surgery.

RESULTS

On the first postoperative day, 12 eyes from group A (9.5%) exhibited a shallow anterior chamber with marked hypotony and no eyes in group B showed flat anterior chamber at any control evaluation (P<0.001). The day after surgery, group A showed a mean IOP of 5.3 mm Hg (± 2.02), whereas group B had a mean of 7.4 mm Hg (± 2.10). At 7 days postoperation, the values for IOP were 10.95 (± 1.55) and 11.7 mm Hg (± 1.66) in groups A and B, respectively. One month later, mean IOP was 11.05 mm Hg (± 1.08) for group A and 13.9 mm Hg (± 3.26) for group B. The surgeon removed the compression sutures from all eyes with IOP>14 mm Hg (90%). The day after suture removal, mean IOP decreased to 10.45 mm Hg (± 1.37). There was no significant statistical difference in visual acuity between the 2 groups at any point during follow-up (P>0.001). At 180 postoperative days the difference in mean IOP between the 2 groups was statistically significant (P<0.001).

CONCLUSIONS

The application of removable corneoscleral compression sutures during trabeculectomy reduced the risk of postoperative shallow anterior chamber and allowed for safe IOP control after the procedure giving further postoperative chance to reduce the intraocular pressure.

Perioperative conjunctival inflammation and trabeculectomy outcome

PURPOSE

To correlate subclinical conjunctival inflammation and trabeculectomy results.

METHODS

Prospective case series of 28 patients with primary open-angle glaucoma (28 eyes) under topical anti-glaucoma medication who underwent trabeculectomy. During surgery, a sample from the inferior bulbar conjunctiva was collected and the expression of HLA-DR together with the presence of inflammatory cells was correlated with trabeculectomy outcomes after 24 months. Surgical success was defined as intraocular pressure between 6 and 20 mmHg irrespective of the use of anti-glaucoma medication.

RESULTS

Five patients missed follow-up visits and were removed from the study. Ten eyes (43.5%) were HLA-DR(+), but no significant differences were observed between eyes with successful and failed surgeries (p = 0.214). There was no significant association between the number of neutrophils and surgical outcomes (p = 0.353).

CONCLUSIONS

The presence of inflammatory cells and expression of the inflammation marker HLA-DR in the conjunctiva did not correlate with the prognosis of trabeculectomy in this study.