Factors influencing the filtration-bleb volume after Ex-PRESS® surgery

Contributing factors for intraocular pressure control in patients with mostly normal-tension glaucoma after initial Ex-PRESS drainage device implantation

PURPOSE

To investigate the postoperative intraocular pressure (IOP) control and identify the factors associated with failure of initial Ex-PRESS surgery in patients with open-angle glaucoma for 3 years.

METHODS

A total of 79 patients with medically uncontrolled open-angle glaucoma (55 normal-tension glaucoma and 24 primary open-angle glaucoma) were enrolled. All patients underwent Ex-PRESS implantation (including combined cataract surgery). The outcome measure was the survival rate using life table analysis, the failure was defined as IOP of > 18 mmHg (criterion A), > 15 mmHg (criterion B) or > 12 mmHg (criterion C) and/or IOP reduction of < 20% from baseline (each criterion) without any glaucoma medications. The Cox proportional hazards model was used to identify risk factors for IOP management defined as the above criterion.  RESULTS: The mean preoperative IOP was 19.3 ± 5.8 mmHg. At 36 months, the mean IOP was 11.8 ± 3.6 mmHg with a mean IOP change of 7.5 mmHg (reduction rate 39.0%). The cumulative probability of success was 58% (95%CI: 42-64%) (criterion A), 48% (95%CI: 37-59%) (criterion B) and 30% (95%CI: 20-40%) (criterion C). In multivariate analyses, factors that predicted poor IOP control included the intervention of bleb needling after 6 months after the surgery (HR: 2.43; 95%CI: 1.35-4.37; P = 0.032). Transient hypotony was observed in 4 patients.

CONCLUSION

The implementation of bleb needling after Ex-PRESS surgery in the late postoperative period was suggested to be the main risk factor for achieving lower IOP.

Ex-PRESS® surgery versus trabeculectomy for primary open-angle glaucoma with low preoperative intraocular pressure

PURPOSE

To compare surgical outcomes between Ex-PRESS® surgery (EXP) and trabeculectomy (Trab) for primary open-angle glaucoma (POAG) with low preoperative intraocular pressure (IOP).

PATIENTS AND METHODS

This was a retrospective non-randomized study. We included POAG patients with preoperative IOP ≤ 16 mmHg who were taking tolerance glaucoma medications. We compared the surgical outcomes, postoperative IOP, number of glaucoma medications, reduction rate of corneal endothelial cell density (ECD), visual acuity, and postoperative complications between POAG patients who underwent EXP (34 eyes) or Trab (38 eyes) and could be followed up for > 2 years.

RESULTS

Both surgeries significantly decreased the IOP (p < 0.001): At 2 years, EXP provided decreases from 13.4 ± 2.3 to 10.2 ± 3.1 mmHg, and Trab provided decreases from 13.5 ± 2.0 to 8.9 ± 3.2 mmHg. No significant differences were observed in the postoperative IOP (p = 0.076), number of postoperative medications (p = 0.263), success rate (p = 0.900), reduction rate of ECD (p = 0.410), or difference in visual acuity (p = 0.174). The reduction rate of IOP was significantly high in the Trab group (p = 0.047).

CONCLUSIONS

Both surgeries significantly decreased IOP and were useful surgical methods for low-IOP glaucoma. Our results suggest that trabeculectomy can decrease IOP more than Ex-PRESS surgery but might have more complications.

[Anti-scarring effect of rapamycin following filtering surgery in rabbit eyes]

OBJECTIVE

To study the effect of rapamycin on scar formation in rabbit eyes following filtering operation and explore the possible mechanism.

METHODS

Ninety-six healthy adult rabbits were subjected to trabeculectomy of the left eye and subsequently randomly divided into 4 groups (n=24) for treatment with castor oil (control) or rapamycin (1%, 3%, or 5%) eye drops of the operated eyes 4 times a day. The morphology and function of the filtering blebs of the rabbits were compared at 7, 14, 21 and 28 days after the operation; at each of the time points, 6 rabbits from each group were euthanized for detection of expressions of proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA) in the tissues in the surgical area using immunohistochemistry. Cultured rabbit subconjunctival fibroblasts (RTFSs) were treated with different concentrations of rapamycin (0.06, 0.25, 1, and 4 mg/L) and the cell apoptosis was detected using flow cytometry.

RESULTS

In the first, second and third weeks after the operation, the rate of functional follicle formation was significantly higher in the 3 rapamycin groups than in the control group (P < 0.05), and the number of α- SMA-positive fibroblasts decreased over time in the 3 rapamycin groups. In cultured RTFSs, treatment with rapamycin at different concentrations resulted in increased apoptosis of the cells, and rapamycin above 0.25 mg/L significantly increased the cell apoptosis in a dose-dependent manner.

CONCLUSIONS

Rapamycin can inhibit hyperplasia of the filtering passage tissue, helps to preserve the functional filtering blebs and prolong their life span, and induces apoptosis of RTFS.

EX-PRESS Glaucoma Filtration Device: Management of Complications

The EX-PRESS glaucoma filtration device appears to be an effective addition to our options to treat refractory glaucoma. The possibility to create a sclerostomy without tissue excision provides a safe and reliable outflow pathway for aqueous that is standard in size, reducing much of the variability associated with a surgical procedure. Prospective randomized studies comparing EX-PRESS implantation with trabeculectomy show encouraging results. However, complications usually encountered in filtration surgery have been reported, and EX-PRESS implantation can also lead to specific device-related complications. This article reviews the most common complications associated with this procedure.

Factors influencing the reduction in corneal endothelial cells after Ex-Press® surgery

PURPOSE

We investigated the factors that influence the reduction in corneal endothelial cells after Ex-Press^® surgery.

METHODS

This was a retrospective study. We included patients who had undergone Ex-Press surgery and were followed up for > 2. We analyzed the corneal endothelial cell density (ECD) before and after Ex-Press surgery. We investigated the insertion position (Ex-Press device was inserted into cornea or trabecular meshwork (TM)), Ex-Press-iris touch, cornea-iris touch, peripheral anterior synechiae, history of trabeculotomy, history of selective laser trabeculoplasty, type of glaucoma, and simultaneous cataract surgery as influencing factors. We used multivariate analysis to determine the factors influencing the reduction rate of ECD.

RESULTS

We included 129 eyes. The mean of ECD had decreased 7.0% at 2 years. Ex-Press surgeries significantly decreased the ECD after 2 years (p = 0.0118). As a result of the multivariate analysis, the factor that led to a significantly faster reduction in ECD was the insertion position of the Ex-Press (p < 0.0001). The reduction rate of ECD after 2 years in cases of insertion into the cornea (27 eyes) was 15.1 ± 3.6%, and in cases of insertion into a TM (102 eyes), it was 5.2 ± 1.4%.

CONCLUSIONS

Insertion into the cornea was a risk factor for rapid ECD loss. The Ex-Press should be inserted into a TM for long-term protection of the corneal endothelial cells.

Glaucoma Filtering Bleb Analysis Before and After Aponeurotic Blepharoptosis Surgery

PURPOSE

To evaluate the effectiveness and safety of aponeurotic blepharoptosis surgery and the morphology of filtering bleb in patients with filtrating bleb.

METHODS

This retrospective case series included 7 consecutive patients (9 eyes) with filtering bleb after trabeculectomy. They underwent transcutaneous levator aponeurotic advancement from May 2018 to April 2019. The authors evaluated margin reflex distance-1 and intraocular pressure and analyzed filtering bleb morphology, such as filtering bleb volume, filtering bleb height, and filtering bleb wall thickness, using anterior segment optical coherence tomography before and after aponeurotic advancement. The authors also evaluated intra and postoperative complications.

RESULTS

The mean age was 75.6 ± 7.8 years; the mean duration from glaucoma surgery to blepharoptosis surgery was 36.9 ± 26.8 months; the mean follow-up after blepharoptosis surgery was 6.1 ± 2.9 months. The mean margin reflex distance-1 value changed significantly from 0.7 ± 0.8 mm before surgery to 3.3 ± 0.4 mm after surgery (p < 0.0001). The mean intraocular pressure showed no significant change from 12.9 ± 2.6 mm Hg before surgery to 12.7 ± 3.3 after surgery. In the filtering bleb analysis using anterior segment optical coherence tomography no significant differences were found, such as in bleb volume, height and wall thickness, before and after blepharoptosis surgery. There were no intraoperative complications in any of the cases. A postoperative corneal disorder was seen in 1 eye, but there was no infection of or damage to filtering bleb in any of the cases during the postoperative follow-up period.

CONCLUSIONS

In patients with glaucoma filtering bleb, transcutaneous levator aponeurotic ptosis surgery is considered to be safe and unlikely to affect the morphology of the filtering bleb or intraocular pressure in the short term.In patients with glaucoma filtering bleb, transcutaneous levator aponeurotic ptosis surgery is considered to be highly safe and unlikely to affect the morphology of the filtering bleb or intraocular pressure in the short term.