Glaucoma drainage device implantation and cyclophotocoagulation in the management of refractory glaucoma after Descemet-stripping automated endothelial keratoplasty

AIM:To compare the surgical outcomes of glaucoma drainage device implantation(GDI)and trans-scleral neodymium:YAG cyclophotocoagulation(CPC)in the management of refractory glaucoma after Descemetstripping automated endothelial keratoplasty(DSAEK).METHODS:This retrospective study on observational case series enrolled 29 patients who underwent DSAEK and posterior anti-glaucoma surgery(15 with GDI and 14 with CPC).The main outcome measures were intraocular pressure(IOP),glaucoma surgery success rate(defined as IOP of 6–21 mm Hg without additional anti-glaucoma operation),number of glaucoma medications,endothelial graft status,and best-corrected visual acuity(BCVA).RESULTS:The mean follow-up time was 34.1 and 21.0mo for DSAEK or glaucoma surgeries,both for the GDI and CPC groups.Both groups showed significant IOP reduction after glaucoma surgery.The GDI group presented a significantly higher success rate in IOP control than the CPC group(60%vs 21.4%,P=0.03).Both procedures significantly decreased the number of glaucoma medications(P=0.03).Forty percent and 57%of cases in the GDI and the CPC group,respectively,experienced endothelial graft failure during follow-up(P=0.36).Significantly worse BCVA after surgery was observed in the CPC group but not in the GDI group.CONCLUSION:Both GDI and CPC significantly decrease IOP in eyes with glaucoma after DSAEK.GDI is preferable to CPC in refractory glaucoma cases after DSAEK,as it manifests a significantly higher success rate for IOP control,similar endothelial graft failure rate,and relatively preserves BCVA than CPC.

Glaucoma drainage implants

Glaucoma drainage devices have traditionally been reserved for refractory glaucoma.However,there is an increasing body of evidence to suggest the use of these implants at an earlier stage in the surgical management of glaucoma.We describe the mechanics behind their function as well as the various implants available.The implants vary in size,surface area and composition and hence the surgical implantation of these devices are described in detail.The knowledge of such devices and their potential complications is fundamental for the successful management of patients who undergo aqueous-shunt surgery.Careful patient selection and optimal postoperative management is critical to the successful patient outcomes.

Combined pars plana vitrectomy and Baerveldt glaucoma implant placement for refractory glaucoma

AIMTo evaluate outcomes of combined pars plana vitrectomy and Baerveldt glaucoma implant (PPV-BGI) placement for refractory glaucoma.METHODSThe medical records of 92 eyes (89 patients) that underwent PPV-BGI were retrospectively reviewed, including 43 eyes with neovascular glaucoma (NVG) and 49 eyes with other types of glaucoma (non-NVG).RESULTSOutcome measures were visual acuity (VA), intraocular pressure (IOP), glaucoma medical therapy, complications, and success [VA>hand motions (HM), IOP≥6 mm Hg and ≤21 mm Hg, no subsequent glaucoma surgery]. Cumulative success rates for the non-NVG group and NVG group were 79% and 40% at 1y, respectively (P=0.038). No difference in the rates of surgical success were found between pars plana and anterior chamber tube placement. Preoperative IOP (mean±SD) was 30.3±11.7 mm Hg in the Non-NVG group and 40.0±10.6 mm Hg in the NVG group, and IOP was reduced to 15±9.5 mm Hg in the non-NVG group and 15±10.5 mm Hg in the NVG at 1y. Number of glaucoma medications (mean±SD) decreased from 2.7±1.3 in the non-NVG group and 2.8±1.3 in the NVG group preoperatively to 0.76±1.18 in the non-NVG group and 0.51±1.00 in the NVG group at 1y. Improvement in VA of ≥2 Snellen lines was observed in 25 (27%) eyes, although only 33% of non-NVG eyes and 2.3% of NVG eyes maintained VA better than 20/200 at 1y. Nonclearing vitreous hemorrhage was the most common postoperative complication occurring in 16 (17%) eyes, and postoperative suprachoroidal hemorrhages developed in 5 (5.4%) eyes.CONCLUSIONPPV-BGI is a viable surgical option for eyes with refractory glaucoma, but visual outcomes are frequently poor because of ocular comorbidities, especially in eyes with NVG. The location of tube placement does not influence surgical outcome and should be left to the discretion of the surgeon.

Bio-modulation of scaring Glaucoma Filtration Surgery using a novel application of coated magnesium

Filtration surgery still plays a mainstream role of treatment for glaucoma.Postoperative scarring is the main cause of surgical failure.This study evaluated the biocompatibility and anti-proliferative properties of pure magnesium with three different coatings,which are hydroxyapatite(HA),dicalcium phosphate dihydrate(DCPD)and DCPD+stearic acid(SA),in a primary culture of human tenon's capsule fibroblasts(HTCFs)and in rabbit Glaucoma Filtration Surgery.Titanium and glass were used as controls in vitro,and trabeculectomy was used as control in vivo.The results show the number and shape of HTCFs seeded on different coatings showed less quantity and poor cell morphology.Each type of coated magnesium demonstrated significantly decreased metabolic activity of HTCFs.DCPD+SA showed higher cytotoxicity than the other coatings.Significant inhibition of proliferation was observed with the DCPD+SA coating.The expression ofα-SMA was decreased in the cells when seeded on all of the coated magnesium disks.In vivo,no obvious adverse effects were observed after operation.No significant difference existed for any of the different samples regarding different ion concentrations in the aqueous humor.The inflammatory response in the titanium,DCPD and DCPD+SA treated eyes was more intense than in the trabeculectomy alone and HA groups.Western Blot analysis showed that collagen-1 andα-SMA expression was significantly lower in the titanium,HA,DCPD and DCPD+SA groups compared with the control.Different coatings on magnesium were able to affect the corrosive properties,which in turn,influenced the morphology and function of HTCFs.HA coated magnesium may be considered a very promising biodegradable material for the next generation of glaucoma drainage devices.

Dealing with pediatric glaucoma: from medical to surgical management-a narrative review

Pediatric glaucoma is a potentially sight-threatening disease and is considered the second leading cause of treatable childhood blindness.Pediatric glaucoma is a clinical entity including a wide range of conditions:primary congenital glaucoma,glaucoma secondary to ocular(e.g.,aniridia,Peter’s anomaly),or systemic disease(e.g.,Sturge Weber)and glaucoma secondary to acquired condition(pseudophakic,traumatic,uveitic glaucoma).The treatment algorithm of childhood glaucoma is a step-by-step approach,often starting with surgery,as in primary congenital glaucoma cases.Medical therapy is also crucial in the management of pediatric glaucoma.Here we reported the results of the randomized,controlled,clinical trials carried out in children treated with topical anti-glaucoma drugs.It is worth knowing that prostaglandin analogues showed an excellent systemic safety profile,while serious systemic events have been reported in children taking topical beta-blockers.Angle surgery is the first surgical option in patients diagnosed with primary congenital glaucoma,with ab interno and ab externo approaches showing similar outcomes.Trabeculectomy in children can be troublesome,as mitomycin C(MMC)can lead to bleb complications and a higher endophthalmitis rate than in adults.Glaucoma drainage devices(GDD)are no longer a last resort and can be considered a suitable option for the management of uncontrolled pediatric glaucoma after angle surgery failure.

Development and material characteristics of glaucoma surgical implants

Background:Glaucoma is the leading cause of irreversible blindness worldwide.The reduction of intraocular pressure has proved to be the only factor which can be modified in the treatment,and surgical management is one of the important methods for the treatment of glaucoma patients.Main text:In order to increase aqueous humor outflow and further reduce intraocular pressure,various drainage implants have been designed and applied in clinical practice.From initial Molteno,Baerveldt and Ahmed glaucoma implants to the Ahmed ClearPath device,Paul glaucoma implant,EX-PRESS and the eyeWatch implant,to iStent,Hydrus,XEN,PreserFlo,Cypass,SOLX Gold Shunt,etc.,glaucoma surgical implants are currently undergoing a massive transformation on their structures and performances.Multitudinous materials have been used to produce these implants,from original silicone and porous polyethylene,to gelatin,stainless steel,SIBS,titanium,nitinol and even 24-carat gold.Moreover,the material geometry,size,rigidity,biocompatibility and mechanism(valved versus nonvalved)among these implants are markedly different.In this review,we discussed the development and material characteristics of both conventional glaucoma drainage devices and more recent implants,such as the eyeWatch and the new minimally invasive glaucoma surgery(MIGS)devices.Conclusions:Although different in design and materials,these delicate glaucoma surgical implants have widely expanded the glaucoma surgical methods,and improved the success rate and safety of glaucoma surgery significantly.However,all of these glaucoma surgical implants have various limitations and should be used for different glaucoma patients at different conditions.

Comparison of FP-7 and S-2 Ahmed glaucoma valve implantation in refractory glaucoma patients for short-term follow-up

Background Ahmed glaucoma valves （AGV） has been used for decades, but there is no detailed report about the efficacy of AGV in Chinese glaucoma patients. This study aimed to compare the intraocular pressure （IOP） lowering efficacy and side effects of S-2 polypropylene and PF-7 silicone AGV implantation in Chinese refractory glaucoma patients.Methods Patients were divided into S-2 model AGV group and FP-7 model AGV group. The complete and qualified surgical success rate, change of IOP, number of anti-glaucoma medications used and postoperative complications were recorded and analyzed.Results Average follow-up time was comparable between two groups. IOP was reduced from （37.9±12.7） mmHg preoperatively to （17.3±5.3） mmHg at the last follow-up in S-2 group and reduced from （39.9±14.4） mmHg to （17.7±4.9）mmHg in FP-7 group. Anti-glaucoma medications were reduced from 3.8±0.2 to 1.5±0.2 in S-2 group, and 3.5±0.2 to 0.7±0.2 in FP-7 groups. The cumulative success rates were comparable in two groups, which were 61.2% and 72.1% in S-2 group and FP-7 group respectively. When IOP reduction criteria was used, complete success rates were 30.6% and 51.2% for S-2 and FP-7 groups, and qualified success rates were 86.1% and 92.7% separately. In both groups, the major complication was hypotony, and the previous trabeculectomy of patients was the major risk factor for surgery failure.Conclusions In this short-term retrospective study, S-2 AGV is showed at least as effective as FP-7 AGV in IOP reduction, but associated with higher rate of complications. Previous trabeculectomy is a principle risk factor for AGV implantation failure. These clinical outcomes are important for converting use of the FP-7 silicon AGV in Chinese refractory glaucoma patients.