Long-term success of ahmed glaucoma valve in refractory glaucoma

Long-term comparison of the outcomes of Ahmed Glaucoma Valve surgery between glaucoma surgeons and cornea trained surgeons

PURPOSE

To compare the long-term outcomes obtained by glaucoma surgeons versus cornea trained surgeons performing Ahmed glaucoma valve (AGV) surgery.

METHODS

Of the total 376 patients (3 month to 83 year) conducted in this retrospective study, 130 patients with refractory glaucoma were evaluated who had been followed up for at least six months during ten years period. The primary outcome measure was the surgical success of AGV surgery that was categorized in two groups: (A5 ≤ IOP ≤ 21 mmHg and at least 20% reduction in IOP without any glaucoma medications (complete success) and reduction by using one or more glaucoma medications (qualified success) (B) similar to previous criteria but the cutoff for higher IOP at 16 mmHg without vision loss and the need for medication or re-surgery.

RESULTS

Mean age of the patients was 32.99 ± 24.20 years in the glaucoma surgeon group and 25.18 ± 24.33 years in the cornea trained surgeons group (P = 0.07). The overall success of both methods at the end of four years were 66.7% and 41.7% for the group of glaucoma surgeons and cornea trained surgeons, respectively (p = 0.661). The cumulative success according to criterion A and B was 66.7% in the glaucoma surgeon group and 47.1% in the others surgeon group (P = 0.661). Repeated glaucoma surgery was required in 33.3% and 52.9% of the patients in the glaucoma surgeon and cornea trained surgeons groups, respectively (P = 0.661). Although there was a significant difference for IOP among various follow-up periods (p = 0.004), this difference was not significant between the two groups (p = 0.374).Visual Acuity did not have a signifiant difference between various follow-up periods and surgeons groups (p = 0.419 and P = 0. 690, respectively).

CONCLUSION

There were comparable outcomes with regard to complications and success rates between glaucoma surgeons and cornea trained surgeons performing AGV surgery.

Safety and Efficacy of Ahmed Valve on Intractable Glaucoma in Saudi Population

PURPOSE

The study aims to assess the efficacy and safety of Ahmed glaucoma valve implant in eyes with intractable glaucoma and to evaluate the risk factors for failure.

METHODS

A retrospective evaluation of 83 patients (117 eyes) with intractable glaucoma who underwent silicone Ahmed glaucoma valve implant was done in a tertiary care center in Riyadh, Saudi Arabia, between January 2014 and December 2016. Complete success was defined as intraocular pressure (IOP) ≤21 mmHg without medication after a minimum follow-up of 6 months.

RESULTS

Eighty-three patients (117 eyes) with intractable glaucoma were evaluated. After a mean follow-up duration of 20.8 ± 3.1 (12-24) months, the overall success rate was achieved in 104 eyes (88.9%). Thirty-six eyes (30.8%) had a complete success rate, whereas 68 eyes (58.1%) had a qualified success rate. Thirteen eyes (11.1%) failed to achieve controlled IOP. The postoperative probability to fail was found to be increasing with time from 0.9% (0.9) in the 1^st month to 11.1% (9.9) after 1 year. Complications included a hypertensive phase in 25 eyes (21.4%), encapsulation in 10 eyes (8.5%), hyphema in 7 eyes (6%), hypotony in 2 eyes (1.7%), and blood clots in the implanted tube in 2 eyes (1.7%). The presence of hyphema, scleral patch, and coronary heart diseases was found to increase the risk of failure after Ahmed valve implantation (P = 0.006, 0.040, and 0.014, respectively).

CONCLUSIONS

Ahmed glaucoma valve implant was safe and effective in treating cases of intractable glaucoma.

Glaucoma Drainage Device Coated with Mitomycin C Loaded Opal Shale Microparticles to Inhibit Bleb Fibrosis

Excessive fibrosis is the topmost factor for the defeat of surgical glaucoma drainage device (GDD) implantation. Adjuvant drug approaches are promising to help reduce the scar formation and excessive fibrosis. Opal shale (OS), as a natural state and noncrystalline silica substance with poriferous nature and strong adsorbability, is highly likely to undertake drug loading and delivery. Here, we employed OS microparticles (MPs) by ultrasound and centrifugation and presented an innovative and improved GDD coated with OS MPs, which were loaded with mitomycin C (MMC). MMC-loaded OS MPs were physically absorbed on the Ahmed glaucoma valve surface through OS' adsorbability. About 5.51 μg of MMC was loaded on the modified Ahmed glaucoma valve and can be released for 18 days in vitro. MMC-loaded OS MPs inhibited fibroblast proliferation and showed low toxicity to primary Tenon's fibroblasts. The ameliorated drainage device was well tolerated and effective in reducing the fibrous reaction in vivo. Hence, our study constructed an improved Ahmed glaucoma valve using OS MPs without disturbing aqueous humor drainage pattern over the valve surface. The modified Ahmed glaucoma valve successfully alleviated scar tissue formation after GDD implantation surgery.

Long-term results of Ahmed glaucoma valve implantation in Egyptian population

AIM

To evaluate the long-term results and complications of Ahmed glaucoma valve (AGV) implantation in a cohort of Egyptian patients.

METHODS

A retrospective study of 124 eyes of 99 patients with refractory glaucoma who underwent AGV implantation and had a minimum follow-up of 5y was performed. All patients underwent complete ophthalmic examination and intraocular pressure (IOP) measurement before surgery and at 1d, weekly for the 1^st month, 3, 6mo, and 1y after surgery and yearly afterward for 5y. IOP was measured by Goldmann applanation tonometry and/or Tono-Pen. Complications and the number of anti-glaucoma medications needed were recorded. Success was defined as IOP less than 21 mm Hg with or without anti-glaucoma medication and without additional glaucoma surgery.

RESULTS

Mean age was 23.1±19.9y. All eyes had at least one prior glaucoma surgery. IOP was reduced from a mean of 37.2±6.8 to 19.2±5.2 mm Hg after 5y follow-up with a reduced number of medications from 2.64±0.59 to 1.81±0.4. Complete and qualified success rates were 31.5% and 46.0% respectively at the end of follow-up. The most common complications were encapsulated cyst formation in 51 eyes (41.1%), complicated cataract in 9 eyes (7.25%), recessed tube in 8 eyes (6.45%), tube exposure in 6 eyes (4.8%) and corneal touch in 6 eyes (4.8%). Other complications included extruded AGV, endophthalmitis and persistent hypotony. Each of them was recorded in only 2 eyes (1.6%).

CONCLUSION

Although refractory glaucoma is a difficult problem to manage, AGV is effective and relatively safe procedure in treating refractory glaucoma in Egyptian patients with long-term follow-up. Encapsulated cyst formation was the most common complication, which limits successful IOP control after AGV implantation. However, effective complications management can improve the rate of success.

Ahmed glaucoma valve implant: surgical technique and complications

Implantation of Ahmed glaucoma valve is an effective surgical technique to reduce intraocular pressure in patients affected with glaucoma. While in the past, the use of this device was reserved to glaucoma refractory to multiple filtration surgical procedures, up-to-date mounting experience has encouraged its use also as a primary surgery for selected cases. Implantation of Ahmed glaucoma valve can be challenging for the surgeon, especially in patients who already underwent previous multiple surgeries. Several tips have to be acquired by the surgeon, and a long learning curve is always needed. Although the valve mechanism embedded in the Ahmed glaucoma valve decreases the risk of postoperative hypotony-related complications, it does not avoid the need of a careful follow-up. Complications related to this type of surgery include early and late postoperative hypotony, excessive capsule fibrosis around the plate, erosion of the tube or plate edge, and very rarely infection. The aim of this review is to describe surgical technique for Ahmed glaucoma valve implantation and to report related complications.

The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery

The treatment of refractory glaucoma (RG) is challenging. The commonly adopted strategy in RG treatment is a glaucoma drainage device (GDD) implantation, which despite its radical nature may not always provide the desired intraocular pressure (IOP) levels for a long term. This review is based on the scientific literature on Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. The technique of AGV implantation is described and data for both the types, FP7 and FP8 performance are presented. The outcome with adjunct antimetabolite and anti-VEGF drugs are also highlighted. An insight is given about experimental and histological examinations of the filtering bleb encapsulation. The article also describes various complications and measures to prevent them.

How to cite this article: Bikbov MM, Khusnitdinov II. The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery. J Curr Glaucoma Pract 2015;9(3):86-91.

Long-term Outcomes of Ahmed Glaucoma Valve Implantation in Refractory Glaucoma at Farabi Eye Hospital, Tehran, Iran

PURPOSE

To describe long-term outcomes and complications of Ahmed glaucoma valve (AGV) implantation in subjects with refractory glaucoma at Farabi Eye Hospital, Tehran, Iran.

MATERIALS AND METHODS

This retrospective cohort study evaluated patient records of all subjects with refractory glaucoma who had undergone AGV implantation up to January 2013. The main outcome measure was the surgical success rate. Complete success was defined as intraocular pressure (IOP) <22 mmHg, without anti-glaucoma medications or additional surgery. Qualified success was IOP <22 mmHg regardless of number of anti-glaucoma medications. In all cases, loss of vision (no light perception) was considered an independent indicator of failure. Data were also collected on intraoperative and postoperative complications.

RESULTS

Twenty-eight eyes were included in the study. With a mean follow-up of 48.2 ± 31.7 months (median: 40.50 months; range: 3-124 months), the IOP decreased from a mean preoperative value of 30.8 ± 5.6 mmHg to 20.0 ± 6.4 mmHg at last visit. The number of medications decreased from 3.7 ± 0.4 preoperatively to 2.5 ± 1.1 postoperatively. Cumulative qualified success was achieved in 69% of eyes. Mean time to failure according to qualified success criteria was 92.3 ± 9.4 months. Postoperative complications were recorded in 16 (57.1%) eyes. The most common complication was focal endothelial corneal decompensation at the site of tube-cornea touch.

CONCLUSION

AGV implantation with adjunctive topical anti-glaucoma drops controlled IOP in approximately 70% of eyes with refractory glaucoma with a median of 40.5 months of follow-up. However, complication rates were higher.

Outcomes of Ahmed valve surgery for refractory glaucoma in Dhahran, Saudi Arabia

AIM

To evaluate the outcomes of Ahmed glaucoma valve (AGV) implantation surgery for refractory glaucoma.

METHODS

This one-armed historical cohort study was conducted in 2011. Refractory glaucoma was defined as eyes with an intraocular pressure (IOP) greater than 21 mm Hg with maximally tolerated glaucoma medications, failed surgeries, or both. For all eyes with refractory glaucoma that underwent AGV implantation, data were collected on IOP, the best corrected visual acuity (BCVA) and glaucoma medications preoperatively and 4, 6, 12, 24 and 56wk postoperatively. Logarithm values of IOP were calculated and compared.

RESULTS

The study group was comprised of 30 patients (30 eyes, 16 males and 14 females) with refractory glaucoma. Mean preoperative IOP was 39.3±13.8 mm Hg. Postoperative mean IOP was 15.7±7.1 mm Hg, 19.6±12.8 mm Hg and 13.9±14.2 mm Hg at 12, 24 and 56wk respectively. BCVA was ≥ 6/60 in 11 eyes preoperatively, and five eyes had BCVA≥6/60 at 56wk postoperatively. Preoperatively, more than four medications were used to treat glaucoma in 21 eyes. At 12wk postoperatively, no medications were required to control IOP in 20 eyes. At 56wk postoperatively, at least one medication was required to control IOP in 10 eyes. Over the entire follow up period, four eyes were treated with yttrium aluminium garnet (YAG) laser and 14 eyes required a second surgery. The AGV was removed in four eyes.

CONCLUSION

AGV implantation reduced IOP and the number of medications required to control refractory glaucoma. However, there was a higher risk of decreased vision. Long-term follow up and prompt intervention are recommended.

Comparison of the outcome of silicone Ahmed glaucoma valve implantation with a surface area between 96 and 184 mm² in adult eyes

Purpose

To compare the success rates, complications, and visual outcomes between silicone Ahmed glaucoma valve (AGV) implantation with 96 mm² (FP8) or 184 mm² (FP7) surface areas.

Methods

This study is a retrospective review of the records from 132 adult patients (134 eyes) that underwent silicone AGV implant surgery. Among them, the outcomes of 24 eyes from 24 patients with refractory glaucoma who underwent FP8 AGV implantation were compared with 76 eyes from 76 patients who underwent FP7 AGV implantation. Preoperative and postoperative data, including intraocular pressure (IOP), visual acuity, number of medications, and complications were compared between the 2 groups.

Results

There were no significant differences in baseline characteristics between the 2 groups (p > 0.05). The postoperative visual acuity of the patients in the FP8 group was better than that of the patients in the FP7 group in some early postoperative periods (p < 0.05); however, after 10 postoperative months, visual acuity was not significantly different through the 3-year follow-up period (p > 0.05). Postoperative IOP was not significantly different between the 2 groups (p > 0.05) except for IOP on postoperative day 1 (11.42 mmHg for the FP7 group and 7.42 mmHg for the FP8 group; p = 0.031). There was no statistical difference in success rates, final IOP, number of medications, or complication rates between the 2 groups (p > 0.05).

Conclusions

The FP7 and FP8 AGV implants showed no difference in terms of vision preservation, IOP reduction, and number of glaucoma medications required.

Tube Exposure Repair

All across the world, glaucomatologists are adopting broader use of glaucoma drainage implants even as a primary surgical modality. To avoid tube exposure, which may predispose the eye to endophthalmitis, the implanted tube must be covered by a patch graft. However, these patch grafts also carry a high rate of progressive thinning and erosion, which is believed to result from the lack of cellular infiltration from the surrounding host conjunctival stroma and poor integration of these patch grafts to the host tissue. An ideal patch graft should offer good tensile strength, be suitable for tectonic support, and have biological activities to promote cellular infiltration by the surrounding host conjunctival stroma, thus reducing progressive allogeneic patch graft thinning/erosion. This review talks about various materials and modalities used for an exposed tube repair.

How to cite this article: Oana S, Vila J. Tube Exposure Repair. J Current Glau Prac 2012;6(3):139-142.