Glaucoma Drainage Surgery Research Articles

Imaging of aqueous outflow in health and glaucoma. Justifying the re-direction of aqueous.

A wave of less invasive surgical options that target or bypass the conventional aqueous outflow system has been incorporated into routine clinical practice to mitigate surgical risks associated with traditional glaucoma drainage surgery. A blanket surgical approach for open-angle glaucoma is unlikely to achieve the desired IOP reduction in an efficient or economical way. Developing a precise approach to selecting the most appropriate surgical tool for each patient is dependent upon understanding the complexities of the aqueous outflow system and how devices influence aqueous drainage. However, homoeostatic control of aqueous outflow in health and glaucoma remains poorly understood. Emerging imaging techniques have provided an opportunity to study aqueous outflow responses non-invasively in clinic settings. Haemoglobin Video Imaging (HVI) studies have demonstrated different patterns of aqueous outflow within the episcleral venous system in normal and glaucomatous eyes, as well as perioperatively after trabecular bypass surgery. Explanations for aqueous outflow patterns remain speculative until direct correlation with findings from Schlemm's canal and the trabecular meshwork are possible. The redirection of aqueous via targeted stent placement may only be justifiable once the role of the aqueous outflow system in IOP homoeostasis has been defined.

A Watchful Eye: A Case Report on The Management of Hypotony Maculopathy after Non-Valved Glaucoma Drainage Device Implantation

Introduction : Low intraocular pressure (IOP) and reduced visual acuity following glaucoma surgery have been linked to a serious complication known as hypotony maculopathy. Here, we report a case of hypotony maculopathy following glaucoma drainage implant which was successfully managed by a conservative approach utilizing oral and topical steroids, resulting in favorable outcomes.
 Case Illustration : A 25-year-old female with juvenile glaucoma presented with low IOP in the right eye (RE) following glaucoma drainage surgery using non-valved implant four months prior. Ophthalmic examination revealed a decrease of IOP (9mmHg to 4mmHg) and visual acuity (6/6 to 6/24). Fundus examination and optical coherence tomography (OCT) of macula was indicating hypotony maculopathy. All glaucoma medications were discontinued and the patient was given oral methylprednisolone 3x8 mg and topical prednisolone acetate three hourly for two months. Subsequent follow-up revealed an increase in IOP to 37mmHg and visual acuity improvement to 6/6. The patient was then given oral and topical antiglaucoma medications to maintain IOP control.
 Discussion : Hypotony and its related sequelae are more common with the non-valved drainage devices. Prompt intervention is crucial for improving visual outcomes. Treatment options include surgical and conservative approach. Closely monitored conservative therapy may also give favorable outcomes similar to surgical approach.
 Conclusion : In advanced cases of glaucoma, extremely low IOP is just as risky as a high IOP. Conservative therapy, including topical and oral corticosteroids, can be employed to reverse hypotony, at the expense of transient IOP rise, in corticosteroid-responsive patients. Restoring normal IOP in a timely manner may improve retinal function.

Aqueous Humor Circulation in the Era of Minimally Invasive Surgery for Glaucoma.

Glaucoma surgery with implantation of aqueous humor draining microstents may compromise long-term corneal health by disrupting aqueous humor circulation. The effect of stent numbers on this circulation was interrogated to determine the number of stents associated with minimal circulation disruption. An in vitro anterior eye model perfusion system was constructed with multiple exit ports. A 3-D model of the anterior eye was imported into ABAQUS CFD, analyzes were carried out for unsteady laminar flow and solved using Navier-Stokes equations. DT Vision Foundry was used to analyze velocity contour plot images. The field variable results output for the CFD model were fluid wall shear, fluid pressure and fluid velocity. In vitro, "aqueous" fluid flow is high through a single stent and "aqueous" stagnation is greatest in the quadrants 180° away. Increasing stent port numbers, results in an exponential decrease in the stagnant flow locations. High wall shear stress was seen in the single stent model and is markedly reduced after a second and subsequent stents are introduced. We identify two factors potentially contributing to corneal compromise post glaucoma drainage surgery: aqueous humor stagnation, remote to the stent site and higher exit flows imparting increased stent exit shear stress (particularly with a single stent). With 4 stents, there is minimal disruption of anterior chamber circulation (mimicking physiological conditions). Furthermore we propose that aqueous humor circulation disruption via the usual single-exit port approach disrupts aqueous humor circulation with long-term consequences for corneal health.

Descemet membrane endothelial keratoplasty after implantation of glaucoma drainage devices

To study the possibility of performing modified Descemet membrane endothelial keratoplasty (DMEK) with maximum graft diameter, and to assess its short-term effectiveness in the treatment of bullous keratopathy (BK) in the presence of a glaucoma drainage device in the anterior chamber. Modified surgery 3/4-DMEK was performed in 9 eyes of 7 patients with BK and Ahmed glaucoma drainage using graft of maximum diameter (11±1 mm). Average follow-up time was 15.3±2.5 months (12 to 18 months). No intraoperative or postoperative complications were observed. Mean ECD after 12 months amounted to 1664±346 cells/mm2, which corresponds to ECD reduction of 34±9.6% (24 to 49%) in comparison to preoperative values. Mean best corrected visual acuity 12 months after surgery increased from 0.04±0.03 (0.01 to 0.1) to 0.3±0.2 (0.04 to 0.7). The last follow-up examination revealed all corneas to have preserved transparency and stable pachymetry measurements (from 488 to 548 µm). Performing 3/4-DMEK with a mega graft for treatment of BK after drainage surgery is technically possible. Absence of Descemet membrane (DM) donor and preservation of DM recipient in the drainage tube plane eliminates its contact with the endothelium. Maximum graft diameter should in the long term help prolong the effectiveness of the surgery.

Дренажная хирургия первичной открытоугольной глаукомы: прошлое, настоящее, будущее

Relevance. Despite many techniques for reducing intraocular pressure, surgical treatment of glaucoma has limited effectiveness. First, due to excessive scarring of new intraocular fluid outflow pathways and second, antifibrotics medicaments are unable to effectively control wound healing. The use of drainages reduces the risk of excessive scarring in the area of the filtration pad and forms several ways of outflow of intraocular fluid. The review presents the following sections: development history, advantages, disadvantages, surgical technique and promising directions of glaucoma drainage surgery. Purpose. Summarizing data on the possibility of drainage surgery, historical aspects, causes of scarring and methods of dealing with them. Provide data on various modern drainage devices that are used not only in Russia and their effectiveness. Material and methods. To perform the review, we searched for literature sources on the abstract databases E-library, PubMed and Scopus for the period up to and including 2018, using the keywords «glaucoma drainage surgery» (in the E-library database), «anti-glaucoma drainage» and «anti-glaucoma drainage device» (in the PubMed and Scopus databases). Abstracts of conferences were excluded from the review. A total of 40 articles related to the review topic were identified. The beginning of publications on this issue in domestic sources dates back to 1970, and in foreign sources to 1987. Results. The review presents the history of development, advantages, disadvantages of surgical techniques and promising areas of glaucoma drainage surgery. Various models of drainage devices, as well as their specific and non-specific complications are described. The effectivenes of various valves were 70%, with an average decrease in the level of IOP by at least 50% from the preoperative values. At the same time, the risk of an increase in the level of IOP above the target values is about 10% per year, which leads to the fact that after 5 years only in 50% of cases drainage devices function effectively. Therefore, studies of biomaterials, forms and techniques of drainage implantation surgery, new controlled-release antifibrotic drugs can positively affect the long-term effectiveness of glaucoma surgery. Conclusion. The data presented in the literature review allow us to identify the most effective models of drainage devices, their effectiveness, implantation techniques and possible complications. Key words: glaucoma, refractory glaucoma, glaucoma drainage surgery, drainages.

Technique of Xen Implant Revision Surgery and the Surgical Outcomes: A Retrospective Interventional Case Series.

PurposeThe Xen® Gel Stent (Allergan, Irvine, CA, USA) is a minimally invasive glaucoma surgery device implanted to reduce intra-ocular pressure (IOP) in glaucoma. The stents can fail to drain post-operatively due to scarring of the conjunctiva around the stent opening. Data on the success rates of revision surgery in patients with Xen stent failure are scarce. We present the first detailed report of the steps, outcomes and complications of Xen revision surgery with 12 months of follow-up data.MethodsWe share our experiences on the circumstances in which to perform Xen revision surgery, the steps of the surgery and the results of a retrospective interventional case series of all Xen revisions performed at a single centre from 2013 to 2018.ResultsA total of 151 Xen implants were inserted into eyes at our tertiary centre during the study period, of which 21 eyes (patients) underwent revision surgery. Mean pre-operative IOP was 26.1 (standard deviation 8.3) mmHg with the patient on two drops of anti-glaucoma medication. Four patients were excluded from the analysis due to incomplete data (medical records were unavailable for 2 patients; 1 patient died shortly after surgery; and 1 patient moved to another area). A non-functioning Xen implant was identified in another patient during revision surgery, and the procedure was converted to a trabeculectomy. The remaining 16 patients were included in the analysis, all of whom had a minimum follow-up of 12 months, with the longest follow-up being 4 years following revision surgery. Of these 16 patients, four required needling and 5-fluorouracil injection in the first 12 months following revision surgery, three required further glaucoma drainage surgery due to the failure of the revision surgery to control IOP in the first year and one suffered bleb-related endophthalmitis at the site of previous trabeculectomy surgery. Mean IOP at 12 months following revision surgery was 16.3 (standard deviation 3.7) mmHg on 0.7 drops of anti-glaucoma medication, which equates to a 37.5% reduction in IOP and a 65% reduction in the amount of IOP-lowering drops required.ConclusionOur study shares experience on when to perform Xen revision surgery and the steps required. The results of our small cohort are the first in the literature and show that revisions can achieve promising IOP and medication reductions. Some patients still require needling in the post-operative period to optimise outcomes.

Limbal Stem Cell Deficiency After Glaucoma Surgery.

To characterize the clinical presentation of limbal stem cell deficiency (LSCD) associated with glaucoma surgeries. This is a retrospective cross-sectional study of patients with LSCD and glaucoma who presented to the Stein Eye Institute at the University of California, Los Angeles, between 2009 and 2018. Patients who underwent trabeculectomy and/or aqueous shunt surgery were included. The severity of LSCD was staged using global consensus guidelines and a clinical scoring system, and basal epithelial cell density was measured by in vivo confocal microscopy. Anatomic locations of glaucoma and non-glaucoma surgeries, locations of LSCD, and severity of LSCD were compared. Fifty-one eyes of 41 patients with LSCD associated with glaucoma surgery were included in this study. LSCD in these patients uniquely featured sectoral replacement of corneal epithelium by conjunctival epithelium, without corneal neovascularization or pannus. The sites of glaucoma surgery strongly correlated with the locations of LSCD (P = 0.002). There was a trend toward increased severity of LSCD in eyes with 2 or more glaucoma surgeries as compared to eyes with 1 glaucoma surgery, although the difference did not reach statistical significance (P = 0.3). Use of topical glaucoma medications correlated with LSCD severity, while the impact of antimetabolites did not reach statistical significance. The location of glaucoma drainage surgery is correlated with the location of LSCD. LSCD associated with glaucoma surgery has clinical features distinct from LSCD resulting from other etiologies. Further study is required to delineate the full impact of glaucoma surgery on limbal stem cell function and survival.

Novel approaches to model effects of subconjunctival blebs on flow pressure to improve clinical grading systems after glaucoma drainage surgery.

Clinical grading systems following glaucoma filtration surgery do not include any effects of the bleb on the intra-ocular pressure and are relatively subjective, therefore carrying the risk of inter and/or intra-observer variability. The main objective of the study is to quantify and model the effect of subconjunctival bleb on flow pressure for assessment of clinical grading following glaucoma surgery. Subconjunctival bleb was created by inserting a tube into ex vivo rabbit eyes via an ab externo approach through the anterior chamber and exiting into the subconjunctival space. Sterile dyed water was injected through the tube into the developing bleb. For the in vitro approach a silicone bleb was created by clamping a circular silicone sheet, injecting dyed water through a fixed resistance outlet tube. Photographic measurements of the bleb height, planform area and pressure were taken as a function of time. Clinical blebs were also collected over a few months. Mathematical algorithm software was used to build the bleb model. Bleb height and volume increase as pressure in the bleb increases. The bleb planform area tended to a constant determined by the section of conjunctiva prior to shunt insertion. These increases were in accordance with the bleb model developed in the Appendix. They show that the pressure in the bleb is related to the resistance of the outflow. The linearity of clinical grading systems is reviewed and a new grading approach is proposed. The pressure in the bleb has a strong dependence on bleb extent, height and a weak dependence on conjunctival thickness. The pressure in a bleb can be estimated from bleb height, radius, and flow rate inlet in agreement with the bleb flow model. These results provide support for an improved bleb categorization system.

Current management of glaucoma.

Glaucoma is an irreversible progressive optic neuropathy, for which the major proven treatment is to lower the intraocular pressure (IOP). Five groups of IOP-lowering eye drops have varying mechanisms of action. Some drops, such as β-blockers and α-2 agonists, have potentially serious systemic side effects. Acetazolamide is the only available oral agent; it is effective at lowering IOP, but significant side effects relegate its use usually to refractory glaucoma. Two new eye drops, netarsudil and latanoprostene bunod, have recently been approved by the United States Food and Drug Administration. Both have novel IOP-lowering mechanisms and target the conventional aqueous outflow system. Selective laser trabeculoplasty is a gentle treatment that enhances conventional aqueous outflow. It may be used as an initial treatment, as a substitute for eye drops, or to delay glaucoma drainage surgery. Recent advancements in glaucoma surgery have seen an influx of minimally invasive glaucoma surgery devices, which are being used more frequently and earlier on in the treatment paradigm. As limited long term data are available, trabeculectomy remains the gold standard IOP-lowering procedure. Improvements in drug delivery are on the horizon. Drug-eluting devices and implants are able to deliver the drug closer to the receptors for an extended period of time. This will improve treatment adherence and efficacy, which are major limitations with current medical therapy.

Phacoemulsification and endocyclophotocoagulation in uncontrolled glaucoma: Three-year results

To describe the 3-year outcomes of combined cataract surgery and 360-degree endocyclophotocoagulation (ECP) in eyes with uncontrolled glaucoma and no previous glaucoma drainage surgery. University Hospital Eye Department, Exeter, United Kingdom. Retrospective case series. The study included patients who had combined cataract surgery and 360-degree ECP. The primary outcome measure was intraocular pressure (IOP) reduction at 3years postoperatively. Secondary outcome measures were the cumulative probability of failure of the surgical procedure at 3years and the complications of surgery. Failure was defined by 1 of 2 criteria: (1) IOP higher than 21mm Hg or lower than 6mm Hg or not reduced by 20% from baseline at the 1-, 2-, or 3-year timepoint and (2) further laser or other surgery to reduce IOP at any timepoint. The study comprised 84 patients (84 eyes). The mean IOP dropped from 18.7mm Hg preoperatively to 13.3mm Hg, 13.8mm Hg, and 14.0mm Hg at 1, 2, and 3years postoperatively, respectively. By the 3-year timepoint, 58.3% had met the criteria for failure. The mean number of glaucoma medications was similar at 2.5 at 3years postoperatively compared with 2.6 preoperatively. Nine patients (10.7%) had a significant complication, but all resolved without long-term sequelae. At 3years postoperatively, combined cataract surgery and 360-degree ECP achieved a modest but significant drop in IOP in phakic patients with uncontrolled glaucoma and no previous drainage surgery. There was a low incidence of serious side effects but nearly 60% were classified as failures by 3years.

Incidence, management and outcome of raised intraocular pressure in childhood-onset uveitis at a tertiary referral centre.

To investigate the incidence, management and outcome of uveitis and raised intraocular pressure (IOP)in children treated at the Manchester Uveitis Clinic (MUC). This was a retrospective, observational study of patients who presented with uveitis under the age of 16 to the MUC from July 2002 to June 2016. A total of 320 children were included in the study. Out of these, 55 (17.2%)patients (75 eyes) were found to have raised IOP requiring treatment. The mean age at diagnosis of uveitis and at first recorded raised IOP was 8.2±4.3 and10.8±3.6 years,respectively. The pre-treatment IOP was 32.3±6.6 mmHg and the IOP at the final visit was 15.5±3.7 mmHg (median follow-up period,43.7 months) on a median number of 0 medications. Twenty-eight eyes (37.3%) required glaucoma drainage surgery, and eight eyes (12.5%) had cyclodiode laser before this. Kaplan-Meier analysis showed that 11.5% of eyes required glaucoma surgery at 1 year after diagnosis of raised IOP, increasing to 50.0% by 5 years. The best-corrected visual acuity at diagnosis of uveitis was 0.26±0.42 logMAR, which remained stable at 0.28±0.65 logMAR at final follow-up visit. Four eyes (5.3%) from fourpatients fulfilled the definition of blindness by the WHO criteria. The mean cup:discratio at final follow-up was 0.4. Our cohort of children with raised IOP appeared to have a good outcome overall through aggressive medical and surgical management. Regular long-term follow-up is recommended, and early surgical intervention in eyes with uncontrolled IOP can prevent loss of vision.

Iatrogenic limbal stem cell deficiency following drainage surgery for glaucoma

ObjectiveTo describe conjunctival epithelial overgrowth of the cornea after surgery for glaucoma. MethodsThis is a retrospective case series (setting: Moorfields Eye Hospital). Fourteen eyes of 13 patients with suspected limbal stem cell deficiency (LSCD) and corneal conjunctivalization after glaucoma drainage surgery. Conjunctivalization was defined as corneal epithelium that demonstrated late stain after topical application of fluorescein. Patient demographics, clinical features, potential risk factors, treatment, and final visual acuity were recorded. Main outcome measures were potential risk factors for conjunctivalization, complications, and response to treatment. ResultsEleven eyes had multiple procedures involving the limbus, and in 11 eyes mitomycin C (MMC) or 5 fluorouracil had been used as an adjunct to reduce fibrosis. Affected eyes typically had a segment of late stain with fluorescein based at the site of previous glaucoma surgery, but in one eye there was total loss of the corneal epithelial phenotype. All eyes previously had topical treatment for their glaucoma but only 2 had an ocular surface disease associated with LSCD. Most cases were asymptomatic, but in 3 eyes there was visual loss when the abnormal phenotype crossed the visual axis. In these 3 eyes there was recurrent epithelial breakdown, often at the interface between the 2 epithelial phenotypes. In one individual, these symptoms resolved after limbal epithelial transfer from the unaffected contralateral eye. ConclusionsGlaucoma drainage surgery can damage the adjacent corneal limbal epithelial stem cell population. This can be associated with recurrent epithelial breakdown and reduced vision. If there is visual loss, limbal epithelial transplantation is a potential treatment option.

Innovations in glaucoma surgery from Dr. Rajendra Prasad Centre for Ophthalmic Sciences.

Trabeculectomy surgery is the current standard of care in glaucoma for achieving a low target intraocular pressure if medical therapy is not adequate. Augmentation of trabeculectomy with antimetabolites brought a revolutionary change in the long-term success rates of trabeculectomy, but along with it came a plethora of complications. There still is a big window for therapeutic innovations on this subject. The foremost target for these innovations is to modulate the wound healing response after glaucoma drainage surgery. Achieving the desired balance between long-term success of filtering blebs versus early failure due to scarring of blebs and hypotony due to dysfunctional filtering blebs poses a unique challenge to the ophthalmologists. Alternatives to trabeculectomy such as glaucoma drainage devices and minimally invasive glaucoma surgeries cannot solve the problem of glaucoma blindness in our country, mainly due to their unpredictable results and unfavorable cost-benefit ratio. In this article, we present a summary of our innovations in glaucoma surgery to advance patient care by making it more effective, safer, and economical.

The use of collagen matrix (Ologen) as a patch graft in glaucoma tube shunt surgery, a retrospective chart review

Purpose: To determine the safety and efficacy of collagen matrix as a patch graft in glaucoma drainage surgery. Collagen matrix grafts may be advantageous because they do not need to be harvested from human donors. Methods: An institutional, retrospective review of 43 patients with at least 12 months follow-up status post-glaucoma drainage implant surgery were evaluated for signs of tube erosion after initial placement of collagen matrix patch graft. Results: Forty-one of 43 eyes (95.3%) required no intervention for patch graft melting with tube erosion. Average time of follow-up was 32 months (range: 12-45). Two cases had tube erosion at 4 months and 26 months post-op requiring tube revision, which was successfully revised with conjunctiva (4 month erosion) and donor sclera (26 month erosion). Conclusion: Our results suggest that collagen matrix patch grafts may be used successfully as a patch graft in glaucoma tube shunt surgery, and may be advantageous because they do not have to be harvested from human donors. It is possible that exposure rates may be higher after longer follow-up and with larger numbers of patients. Further research is needed to compare Ologen to traditional graft materials to conclusively determine the safety and efficacy of collagen matrix as a novel patch graft material.

The use of collagen matrix (Ologen) as a patch graft in glaucoma tube shunt surgery, a retrospective chart review.

Purpose: To determine the safety and efficacy of collagen matrix as a patch graft in glaucoma drainage surgery. Collagen matrix grafts may be advantageous because they do not need to be harvested from human donors. Methods: An institutional, retrospective review of 43 patients with at least 12 months follow-up status post-glaucoma drainage implant surgery were evaluated for signs of tube erosion after initial placement of collagen matrix patch graft. Results: Forty-one of 43 eyes (95.3%) required no intervention for patch graft melting with tube erosion. Average time of follow-up was 32 months (range: 12-45). Two cases had tube erosion at 4 months and 26 months post-op requiring tube revision, which was successfully revised with conjunctiva (4 month erosion) and donor sclera (26 month erosion). Conclusion: Our results suggest that collagen matrix patch grafts may be used successfully as a patch graft in glaucoma tube shunt surgery, and may be advantageous because they do not have to be harvested from human donors. It is possible that exposure rates may be higher after longer follow-up and with larger numbers of patients. Further research is needed to compare Ologen to traditional graft materials to conclusively determine the safety and efficacy of collagen matrix as a novel patch graft material.

This issue of ACTA, printed and electronic

The cover illustration shows a variety of orbital implants that have been used following enucleation. This is discussed by Mourits et al in this issue of ACTA. Prins et al. in the Netherlands review the use of MRI imaging of the brain in eye disease. Structural changes in the visual pathways of the brain are seen in glaucoma, AMD and other eye diseases and might suggest a general neurological disorder. Yassin in Saudi Arabia reviews bleb-related infections following glaucoma filtering surgery. The prognosis is usually good if the infection is limited to the bleb but poor when endophthalmitis develops. de Vries et al. in the Netherlands report that the relatively few patients require glaucoma drainage surgery following vitreoretinal surgery. These patients were more likely to have history of glaucoma, many vitreoretinal operations and silicon oil. Tryggvason et al. in Norway, Iceland and USA examined the hearing of patients with glaucoma and/or exfoliation syndrome. Many individuals have hearing loss, and this was associated with age and male gender but not with glaucoma or exfoliation syndrome. Jonas et al. in Germany report thinning of Bruch's membrane in patients in secondary high axial myopia caused by congenital glaucoma. Timlin et al. in London recommend anterior segment OCT for diagnostic examination of lacrimal puncta. Ringvold and Reubsaet in Norway found that acetylcholine affects corneal epithelial cells in vitro and influences iron channels. Mourits et al. in the Netherlands evaluate complications from different types of orbital implants following enucleation for retinoblastoma. They recommend acrylic implants. Klingenstein et al. in Germany and USA examine microcirculation patterns and suggest that these may guide in differentiating uveal nevi from malignant melanomas. Munch et al. in Denmark and Austria validate the Radner reading chart for reading acuity and speed in a Danish cohort. Breukink et al. in the Netherlands recommend half-dose photodynamic therapy and subthreshold diode micropulse laser for chronic central serous chorioretinopathy. Haas et al. in Austria found no difference in pain during intravitreal injections with 27 and 30 gauge needles. However, 30 gauge needles were preferred by the surgeons. Segal et al. in Israel found an association between anxiety levels and perceived pain during intravitreal injections. Norn documents the history of ophthalmology in Denmark up to 1865. The following articles are published electronically only. They are accessible on www.actaophthalmologica.com, where you can find all published articles of ACTA from the beginning. Kim and Choi in Korea found that early postoperative overcorrection was associated with success in surgical treatment of intermittent exotropia. Creuzot-Garcher et al. in France examined elderly people over 75 years old and found visual impairment (visual acuity <0.3) in 2.3% and increasing to 5.6% in patients over 85 years old. Lee et al. in Korea associated the location of retinal nerve fibre layer defects with peripapillary atrophy in glaucoma patients. Kiliç et al. in Turkey found exfoliation syndrome in 5.7% of a Turkish population and this was associated with advancing age and male gender. Hayes et al. in UK recommend a modification of iontophoresis technique for riboflavin penetration into corneal stroma for cross-linking. Prakash et al. in the United Arab Emirates discuss the differences between central and non-central keratoconus in terms of corneal topography. GamalElDin et al. in Egypt recommend big-bubble technique for Descemet's endothelial grafts. Agrawal et al. in UK and Singapore propose a classification for semi-automated laser flare readings in uveitis. Gupta et al. in Singapore suggest that the visibility of choroidal–scleral interface on OCT images influences choroidal thickness measurements. Fernández-Vigo et al. in Spain found the variation in anterior chamber depth to be associated with age, sex, spherical error, corneal diameter and anterior chamber angle. Njikam et al. in Kenya, Cameroon and Germany report on the epidemiology of diabetic retinopathy in Cameroon. Sansom et al. in UK found an association between systolic blood pressure and ocular perfusion pressure with subfoveal choroidal thickness. Vannozzi et al. in Italy report cytomegalovirus retinitis in a patient who received a dexamethasone implant. Barteselli et al. in Italy and USA report transient structural abnormalities of the retina following intravitreal ocriplasmin injection. Suh and Kee in Korea examined long-term outcome of patients with congenital glaucoma and found that many need reoperation. Mulder et al. in the Netherlands and Belgium suggest shallowing of the anterior chamber to protect the crystalline lens during vitrectomy. Kessel et al. in Denmark discuss early results from preoperative scoring of cataract patients. Mazeikaite et al. in Lithuania and USA report elevated levels of antiphospholipid antibodies in patients with pseudoexfoliation syndrome. Alberti and la Cour in Denmark compare treatment of macular holes with vitrectomy and ocriplasmin. More macular holes are closed after vitrectomy but visual acuity outcomes are similar. Cennamo et al. in Italy recommend transpupillary thermotherapy for choroidal haemangioma. I hope you find This Issue of ACTA informative and interesting.

Reversing the Rubeotic Rampage – Current Approaches in the Management of Neovascular Glaucoma

Neovascular glaucoma is a sight-threatening condition, and can rapidly progress from rubeosis with normal intraocular pressure (IOP), to secondary open-angle glaucoma with raised IOP and finally secondary angle-closure glaucoma with uncontrolled IOP. Early detection and aggressive management with panretinal photocoagulation, intravitreal anti-vascular endothelial growth factor (VEGF), topical aqueous suppressants and valved glaucoma drainage surgery can reduce risk of significant visual loss secondary to neovascular glaucoma. This editorial explores some simple measures that can increase surgical success rates and minimise complications.

Mitomycin C versus 5-Fluorouracil for wound healing in glaucoma surgery.

Raised intraocular pressure is a risk factor for glaucoma. One treatment option is glaucoma drainage surgery (trabeculectomy). Antimetabolites are used during surgery to reduce postoperative scarring during wound healing. Two agents in common use are mitomycin C (MMC) and 5-Fluorouracil (5-FU). To assess the effects of MMC compared to 5-FU as an antimetabolite adjunct in trabeculectomy surgery. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2015), EMBASE (January 1980 to October 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 2 October 2015. We included randomised controlled trials where wound healing had been modified with MMC compared to 5-FU. Two review authors independently selected trials and collected data. The primary outcome was failure of a functioning trabeculectomy one year after surgery. Secondary outcomes included mean intraocular pressure at one year. We considered three subgroups: high risk of trabeculectomy failure (people with previous glaucoma surgery, extracapsular cataract surgery, African origin and people with secondary glaucoma or congenital glaucoma); medium risk of trabeculectomy failure (people undergoing trabeculectomy with extracapsular cataract surgery) and low risk of trabeculectomy failure (people who have received no previous surgical eye intervention). We identified 11 trials that enrolled 687 eyes of 679 participants. The studies were conducted in the United States, Europe, Asia and Africa. Five studies enrolled participants at low risk of trabeculectomy failure, five studies enrolled participants at high risk of failure, and one study enrolled people with both high and low risk of failure. None of the included trials enrolled participants with combined trabeculectomy/cataract surgery.We considered one study to be at low risk of bias in all domains, six studies to be at high risk of bias in one or more domains, and the remaining four studies to be at an unclear risk of bias in all domains.The risk of failure of trabeculectomy at one year after surgery was less in those participants who received MMC compared to those who received 5-FU, however the confidence intervals were wide and are compatible with no effect (risk ratio (RR) 0.54, 95% confidence interval (CI) 0.30 to 1.00; studies = 11; I(2) = 40%). There was no evidence for any difference between groups at high and low risk of failure (test for subgroup differences P = 0.69).On average, people treated with MMC had lower intraocular pressure at one year (mean difference (MD) -3.05 mmHg, 95% CI -4.60 to -1.50), but the studies were inconsistent (I(2) = 52%). The size of the effect was greater in the high-risk group (MD -4.18 mmHg, 95% CI -6.73 to -1.64) compared to the low-risk group (MD -1.72 mmHg, 95% CI -3.28 to -0.16), but again the test for interaction was not statistically significant (P = 0.11).Similar proportions of eyes treated with MMC lost 2 or more lines of visual acuity one year after surgery compared to 5-FU, but the confidence intervals were wide (RR 1.05, 95% CI 0.54 to 2.06).Adverse events occurred relatively rarely, and estimates of effect were generally imprecise. There was some evidence for less epitheliopathy in the MMC group (RR 0.23, 95% CI 0.11 to 0.47) and less hyphaema in the MMC group (RR 0.62, 95% CI 0.42 to 0.91).None of the studies reported quality of life.Overall, we graded the quality of the evidence as low largely because of risk of bias in the included studies and imprecision in the estimate of effect. We found low-quality evidence that MMC may be more effective in achieving long-term lower intraocular pressure than 5-FU. Further comparative research on MMC and 5-FU is needed to enhance reliability and validity of the results shown in this review. Furthermore, the development of new agents that control postoperative scar tissue formation without side effects would be valuable and is justified by the results of this review.

Different strategies and cost-effectiveness in the treatment of primary open angle glaucoma.

Glaucoma is the second highest cause of blindness worldwide with an estimated half of the glaucoma population unaware of their disease. To date, intraocular pressure is the most important modifiable risk factor and lowering it has been proven to reduce progression of visual field loss associated with glaucoma. Different strategies are available to lower intraocular pressure and include medical, laser, or surgical treatment in the form of topical or systemic medications, argon or selective laser trabeculoplasty, and glaucoma drainage surgery such as trabeculectomy, deep sclerectomy, or other drainage devices. The effectiveness of these treatments has been well documented however their cost-effectiveness between the developed world and third world remains unclear.

Ocular Surface Disease Exacerbated Glaucoma

To describe a series of 4 patients with inadequately controlled primary open angle glaucoma and ocular surface disease (OSD) in whom a combination approach was used to manage the OSD resulting in improved intraocular pressure (IOP) control. A retrospective review of the clinical notes of 4 patients referred to a tertiary surgical glaucoma service was performed. At the initial visit, measures to control the OSD were employed in all patients; twice-daily lid hygiene measures, a 3-month course of 50 mg daily oral doxycycline, topical carmellose sodium (celluvisc) 0.5% 4 to 6 times daily, and preservative-free equivalents of topical antiglaucoma medications as deemed appropriate, depending on the perceived severity of the OSD. Patients were reviewed for a maximum of 24 months after intervention. In all patients treatment resulted in a marked symptomatic and clinical improvement in the ocular surface with a reduction in hyperemia, meibomian gland dysfunction and superficial keratopathy. A reduction in the IOP also occurred in all patients, obviating the need for glaucoma drainage surgery during the study period. Patients with severe OSD often have glaucoma that is refractive to medical therapy. Furthermore, the surgical success of glaucoma filtering surgery is compromised in patients with scarring and inflammation of the conjunctiva. The term we postulate is "OSD exacerbated glaucoma." This is the first study to suggest that the use of a combination approach comprising medical treatment to manage the OSD in patients with primary open angle glaucoma may lead to an improvement in the IOP control and the management of glaucoma.