A narrative review on the association of high intraocular pressure and glaucoma in patients with retinal vein occlusion.

Background and Objective: Retinal vein occlusion (RVO) is a major cause of vision loss and elevated intraocular pressure (IOP), high ocular perfusion pressure, and glaucoma are known ophthalmic risk factors for RVO. The aim of this paper is to provide the update on the association and management of high IOP/glaucoma and RVO. Methods: A literature review was performed in PubMed and Medline until May 2022 utilizing specific keywords and cross-matched reference lists. Key Content and Findings: The association of RVO with high IOP/glaucoma may be attributed to retinal ganglion cell loss due to retinal ischemia in high IOP and glaucoma. As new modalities showed, decreased optic disc perfusion, reduced density of blood vessels in the optic nerve head of glaucoma patients, changes in the peripapillary microvascular parameters, and decreased retinal nerve fiber layer (RNFL) thickness of the optic nerve head of eyes with RVO suggest a common pathway between RVO and glaucoma. Literature suggests the close follow up for glaucoma development among patients with non-arteriovenous (AV) crossing (optic cup or optic nerve sited) RVO in fellow eye and management of elevated IOP among RVO cases treated with anti-vascular endothelial growth factor (VEGF) antibodies/corticosteroids and those with preexisting primary open angle glaucoma (POAG). Conclusions: Determining potential patient responses to treatment and considering therapeutic options are challenging among patients with RVO and glaucoma. However, IOP lowering managements in preventing IOP spikes in patients with preexisting glaucoma and early treatment of macular edema in eyes with RVO is recommended.

Prostaglandin-associated periorbitopathy syndrome (PAPS): Addressing an unmet clinical need.

BACKGROUND: Topical prostaglandin analogs (PGAs) are widely approved and preferred first-line options for glaucoma and elevated intraocular pressure (IOP). However, prostaglandin-associated periorbitopathy syndrome (PAPS) is now a well-recognized clinical and cosmetic concern for patients receiving PGAs, especially during long-term and unilateral therapy. PGA-associated periocular changes occur in a substantial proportion of patients, with older patients (>60 years) at greater risk of clinical presentation. PAPS may hinder long-term management of glaucoma, including treatment adherence, ophthalmic surgery outcomes, and reliable IOP measurements. RECOMMENDATION: New therapeutic approaches may address this unmet clinical need. Omidenepag isopropyl (OMDI) is a novel, non-prostaglandin, selective EP2 receptor agonist in ongoing development, which provides a unique pharmacological mechanism of action. OMDI appears to provide IOP reductions comparable to PGAs, but without PAPS-related undesirable effects. OMDI may offer a suitable long-term option for patients who demonstrate decreased efficacy, or failure, of PGAs, plus patients with significant PAPS, while fulfilling international guidelines.

The Canonical Wnt Signaling Pathway Inhibits the Glucocorticoid Receptor Signaling Pathway in the Trabecular Meshwork.

Glucocorticoid-induced glaucoma is a secondary open-angle glaucoma. About 40% of the general population may develop elevated intraocular pressure on prolonged glucocorticoid treatment secondary to damages in the trabecular meshwork (TM), a tissue that regulates intraocular pressure. Therefore, identifying the key molecules responsible for glucocorticoid-induced ocular hypertension is crucial. In this study, Dickkopf-related protein 1 (Dkk1), a canonical Wnt signaling inhibitor, was found to be elevated in the aqueous humor and TM of glaucoma patients. At the signaling level, Dkk1 enhanced glucocorticoid receptor (GR) signaling, whereas Dkk1 knockdown or Wnt signaling activators decreased GR signaling in human TM cells as indicated by luciferase assays. Similarly, activation of the GR signaling inhibited Wnt signaling. At the protein level, glucocorticoid-induced extracellular matrix was inhibited by Wnt activation using Wnt activators or Dkk1 knockdown in primary human TM cells. In contrast, inhibition of canonical Wnt signaling by ß-catenin knockdown increased glucocorticoid-induced extracellular matrix proteins. At the physiological level, adenovirus-mediated Wnt3a expression decreased glucocorticoid-induced ocular hypertension in mouse eyes. In summary, Wnt and GR signaling inhibit each other in the TM, and canonical Wnt signaling activators may prevent the adverse effect of glucocorticoids in the eye.

Cystoid macular edema related to cataract surgery and topical prostaglandin analogs: Mechanism, diagnosis, and management.

Cystoid macular edema (CME) is a form of macular retina thickening that is characterized by the appearance of cystic fluid-filled intraretinal spaces. It has classically been diagnosed upon investigation after a decrease in visual acuity; however, improvements in imaging technology make it possible to noninvasively detect CME even before a clinically significant decrease in central vision. Risk factors for the development of CME include diabetic retinopathy, retinal vein occlusion, uveitis, and cataract surgery. It has been proposed that eyes with elevated intraocular pressure after cataract surgery, including those treated with prostaglandin analog eye drops, may be at higher risk for the development of CME. We summarize the current knowledge of the molecular mechanisms underlying CME, the potential role of ocular surgery and topical glaucoma medication in increasing the risk of CME, the newly developed imaging methods for diagnosing CME, and the clinical management of CME.

The acute and chronic effects of intravitreal anti-vascular endothelial growth factor injections on intraocular pressure: A review.

The acute and chronic effects of repeated intravitreal antivascular endothelial growth factor (VEGF) injections on intraocular pressure have not been fully characterized, and the development of sustained ocular hypertension could adversely affect patients who are at risk of glaucomatous optic neuropathy. As expected, volume-driven, acute ocular hypertension immediately follows intravitreal injection, but this pressure elevation is generally transient and well tolerated. Several medications have been investigated to limit acute ocular hypertension following anti-VEGF therapy, but the benefits of pretreatment are not conclusive. Chronic, sustained ocular hypertension, distinct from the short-term acute ocular hypertension after each injection, has also been associated with repeated intravitreal anti-VEGF injections. Risk factors for chronic ocular hypertension include the total number of injections, a greater frequency of injection, and preexisting glaucoma. Proposed mechanisms for chronic ocular hypertension include microparticle obstruction, toxic or inflammatory effects on trabecular meshwork, as well as alterations in outflow facility by anti-VEGF agents. Although limiting anti-VEGF therapy could minimize the risk of both acute and chronic ocular hypertension, foregoing anti-VEGF therapy risks progression of various macular diseases with resulting permanent central vision loss. While definitive evidence of damage to the retinal nerve fiber layer is lacking, patients receiving repeated injections should be monitored for ocular hypertension and patients in whom sustained ocular hypertension subsequently developed should be periodically monitored for glaucomatous changes with optic nerve optical coherence tomography and static visual fields.

Cost-comparison of two trabecular micro-bypass stents versus selective laser trabeculoplasty or medications only for intraocular pressure control for patients with open-angle glaucoma.

AIM: Patients with open-angle glaucoma (OAG) whose intraocular pressure is not adequately controlled by one medication have several treatment options in the US. This analysis evaluated direct costs of unilateral eye treatment with two trabecular micro-bypass stents (two iStents) compared to selective laser trabeculoplasty (SLT) or medications only. MATERIALS AND METHODS: A population-based, annual state-transition, probabilistic, cost-of-care model was used to assess OAG-related costs over 5 years. Patients were modeled to initiate treatment in year zero with two iStents, SLT, or medications only. In years 1-5, patients could remain on initial treatment or move to another treatment option(s), or filtration surgery. Treatment strategy change probabilities were identified by a clinician panel. Direct costs were included for drugs, procedures, and complications. RESULTS: The projected average cumulative cost at 5 years was lower in the two-stent treatment arm ($4,420) compared to the SLT arm ($4,730) or medications-only arm ($6,217). Initial year-zero costs were higher with two iStents ($2,810) than with SLT ($842) or medications only ($996). Average marginal annual costs in years 1-5 were $322 for two iStents, $777 for SLT, and $1,044 for medications only. The cumulative cost differences between two iStents vs SLT or medications only decreased over time, with breakeven by 5 or 3 years post-initiation, respectively. By year 5, cumulative savings with two iStents over SLT or medications only was $309 or $1,797, respectively. LIMITATIONS: This analysis relies on clinical expert panel opinion and would benefit from real-world evidence on use of multiple procedures and treatment switching after two-stent treatment, SLT, or polypharmaceutical initial approaches. CONCLUSIONS: Despite higher costs in year zero, annual costs thereafter were lowest in the two-stent treatment arm. Two-stent treatment may reduce OAG-related health resource use, leading to direct savings, especially over medications only or at longer time horizons.

Building a Culture of Safety in Ophthalmology.

Patient safety focused on a reduction in both procedural and diagnostic error is the number one concern of the United States healthcare system in the 21st century. The American Board of Ophthalmology has a longstanding interest in patient safety, and in 2015, teamed with the American Academy of Ophthalmology to convene all ophthalmology subspecialties and other prominent national organizations to address patient safety in ophthalmology. This article reviews the topic and highlights concerns for ophthalmologists.

The Ahmed Versus Baerveldt Study: Five-Year Treatment Outcomes.

PURPOSE: To compare 2 frequently used aqueous shunts for the treatment of glaucoma. DESIGN: International, multicenter, randomized trial. PARTICIPANTS: Patients aged 18 years or older with uncontrolled glaucoma despite maximum tolerated medical therapy, many of whom had failed or were at high risk of failing trabeculectomy. METHODS: Eligible patients were randomized to receive an Ahmed-FP7 valve implant (New World Medical, Inc, Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc, Santa Ana, CA) using a standardized surgical technique. MAIN OUTCOME MEASURES: The primary outcome was failure, defined as intraocular pressure (IOP) outside the target range (5-18 mmHg) or reduced <20% from baseline for 2 consecutive visits after 3 months, severe vision loss, or de novo glaucoma surgery. Secondary outcomes measures included IOP, medication use, visual acuity, complications, and interventions. RESULTS: A total of 238 patients were randomized; 124 received the Ahmed-FP7 implant, and 114 received the Baerveldt-350 implant. Baseline characteristics were similar between groups. Mean preoperative IOP was 31.4±10.8 mmHg on 3.1±1.0 glaucoma medications. At 5 years, the cumulative failure rate was 53% in the Ahmed group and 40% in the Baerveldt group (P = 0.04). The main reason for failure in both groups was high IOP, and the cumulative de novo glaucoma reoperation rate was 18% in the Ahmed group and 11% in the Baerveldt group (P = 0.22). Hypotony resulted in failure in 5 patients (4%) in the Baerveldt group compared with none in the Ahmed group (P = 0.02). Mean IOP was 16.6±5.9 mmHg in the Ahmed group (47% reduction) and 13.6±5.0 mmHg in the Baerveldt group (57% reduction, P = 0.001). Mean medication use was 1.8±1.5 mmHg in the Ahmed group (44% reduction) and 1.2±1.3 mmHg in the Baerveldt group (61% reduction, P = 0.03). The 2 groups had similar complication rates (Ahmed 63%, Baerveldt 69%) and intervention rates (Ahmed 41%, Baerveldt 41%). Most complications were transient, and most interventions were slit-lamp procedures. CONCLUSIONS: Both implants were effective in reducing IOP and the need for glaucoma medications. The Baerveldt group had a lower failure rate and a lower IOP on fewer medications than the Ahmed group, but had a small risk of hypotony that was not seen in the Ahmed group.

Integrating the Internship into Ophthalmology Residency Programs: Association of University Professors of Ophthalmology American Academy of Ophthalmology White Paper.

Future ophthalmologists will need to have broad skills to thrive in complex health care organizations. However, training for ophthalmologists does not take advantage of all of the postgraduate years (PGYs). Although the traditional residency years seem to have little excess capacity, enhancing the internship year does offer an opportunity to expand the time for ophthalmology training in the same 4 PGYs. Integrating the internship year into residency would allow control of all of the PGYs, allowing our profession to optimize training for ophthalmology. In this white paper, we propose that we could capture an additional 6 months of training time by integrating basic ophthalmology training into the intern year. This would allow 6 additional months to expand training in areas such as quality improvement or time for "mini-fellowships" to allow graduates to develop a deeper set of skills.

Primary cilia signaling mediates intraocular pressure sensation.

Lowe syndrome is a rare X-linked congenital disease that presents with congenital cataracts and glaucoma, as well as renal and cerebral dysfunction. OCRL, an inositol polyphosphate 5-phosphatase, is mutated in Lowe syndrome. We previously showed that OCRL is involved in vesicular trafficking to the primary cilium. Primary cilia are sensory organelles on the surface of eukaryotic cells that mediate mechanotransduction in the kidney, brain, and bone. However, their potential role in the trabecular meshwork (TM) in the eye, which regulates intraocular pressure, is unknown. Here, we show that TM cells, which are defective in glaucoma, have primary cilia that are critical for response to pressure changes. Primary cilia in TM cells shorten in response to fluid flow and elevated hydrostatic pressure, and promote increased transcription of TNF-α, TGF-ß, and GLI1 genes. Furthermore, OCRL is found to be required for primary cilia to respond to pressure stimulation. The interaction of OCRL with transient receptor potential vanilloid 4 (TRPV4), a ciliary mechanosensory channel, suggests that OCRL may act through regulation of this channel. A novel disease-causing OCRL allele prevents TRPV4-mediated calcium signaling. In addition, TRPV4 agonist GSK 1016790A treatment reduced intraocular pressure in mice; TRPV4 knockout animals exhibited elevated intraocular pressure and shortened cilia. Thus, mechanotransduction by primary cilia in TM cells is implicated in how the eye senses pressure changes and highlights OCRL and TRPV4 as attractive therapeutic targets for the treatment of glaucoma. Implications of OCRL and TRPV4 in primary cilia function may also shed light on mechanosensation in other organ systems.

Efficacy, safety, and survival rates of IOP-lowering effect of phacoemulsification alone or combined with canaloplasty in glaucoma patients.

PURPOSE: To evaluate efficacy and survival rates of intraocular pressure (IOP)-lowering effect obtained with phacoemulsification (phaco) alone or in combination with canaloplasty (PCP) in patients with open-angle glaucoma (OAG). METHODS: Retrospective chart review of consecutive cases at the Department of Ophthalmology, Indiana University. Visual acuity (VA), IOP, number of medications (Meds), failures, and survival rates of IOP-lowering effect were analyzed. Inclusion criteria were: patients older than 18 years with OAG and cataract. Exclusion criteria were: no light perception vision, prior glaucoma surgery, chronic uveitis, angle-closure glaucoma, and advanced-stage or end-stage OAG. Failure criteria were: IOP>21 mm Hg or <20% reduction, IOP<6 mm Hg, further glaucoma surgeries, and loss of light perception vision. RESULTS: Thirty-seven patients underwent phaco and 32 patients had PCP. Follow-up was 21.8±10.1 versus 18.8±9.6 months for phaco and PCP, respectively (P=0.21). Age (y) (74.7±9.8 vs. 76.1±8.3, P=0.54), sex (P=81), and laser status (P=0.75) were similar between the groups. Preoperatively, mean±SD logMAR VA (0.5±0.7 vs. 0.5±0.5, P=0.77), IOP (16.2±4.6 vs. 18.2±5.1, P=0.13), and Meds (1.4±1.1 vs. 1.3±0.7, P=0.75) were similar for phaco and PCP, respectively. At 24-month phaco (n=17) and PCP (n=11), respectively, mean±SD were: logMAR VA 0.2±0.2 versus 0.4±0.7, P=0.29; IOP 14.1±4.0 versus 12.9±3.8, P=0.43; and Meds 1.5±1.2 versus 0.3±0.5, P=0.005. Rates of successful IOP lowering without medications for phaco versus PCP at 12 months were 34% versus 75%, respectively (P=0.003). CONCLUSIONS: A combination of canaloplasty with phaco results in a decreased number of glaucoma medications and increased survival rate of IOP-lowering effect compared with phaco alone.

The Ahmed versus Baerveldt study: three-year treatment outcomes.

OBJECTIVE: To compare 2 commonly used aqueous drainage devices for the treatment of refractory glaucoma. DESIGN: International, multicenter, randomized trial. PARTICIPANTS: Patients aged 18 years or older with uncontrolled or high-risk glaucoma refractory to maximum medical therapy, many of whom had failed trabeculoplasty and trabeculectomy. METHODS: Eligible patients were randomized to an Ahmed-FP7 valve implant (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA) using a standardized surgical technique. MAIN OUTCOME MEASURES: The primary outcome was failure, defined as intraocular pressure (IOP) outside of the target range (5-18 mmHg, with ≥20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, de novo glaucoma procedures, or loss of light perception. Secondary outcome measures include IOP, medication use, visual acuity, complications, and interventions. RESULTS: A total of 238 patients were enrolled and randomized; 124 received the Ahmed implant and 114 received the Baerveldt implant. Baseline characteristics were similar in both groups. Half the study group had secondary glaucoma, and 37% had previously failed trabeculectomy. The mean preoperative IOP was 31.4±10.8 mmHg on 3.1±1.0 glaucoma medications. Median baseline Snellen visual acuity was 20/100. At 3 years, the cumulative probability of failure was 51% in the Ahmed group and 34% in the Baerveldt group (P = 0.03). Mean IOP was 15.7±4.8 mmHg in the Ahmed group (49% reduction) and 14.4±5.1 mmHg in the Baerveldt group (55% reduction; P = 0.09). Mean number of glaucoma medications was 1.8±1.4 in the Ahmed group (42% reduction) and 1.1±1.3 in the Baerveldt group (65% reduction; P = 0.002). There was a moderate but similar decrease in visual acuity in both groups (P< 0.001). The 2 groups had similar complication rates (52% Ahmed, 62% Baerveldt; P = 0.12); however, the Baerveldt group had a higher rate of hypotony-related vision-threatening complications (0% Ahmed, 6% Baerveldt; P = 0.005). More interventions were required in the Baerveldt group, although the difference did not reach statistical significance (38% Ahmed, 50% Baerveldt; P = 0.07). Most complications were transient, and most interventions were slit-lamp procedures. CONCLUSIONS: Both devices were effective in reducing IOP and glaucoma medications. The Baerveldt group had a lower failure rate and required fewer medications than the Ahmed group after 3 years, but it experienced more hypotony-related vision-threatening complications.

The effect of prior trabeculectomy on refractive outcomes of cataract surgery.

PURPOSE: To examine surgical and refractive outcomes of phacoemulsification with intraocular lens (IOL) implant in eyes with prior trabeculectomy. DESIGN: Retrospective observational case-control study. METHODS: The study compared eyes that underwent phacoemulsification with IOL implant at least 3 months post-trabeculectomy (n = 77) with eyes with either medically controlled glaucoma (n = 43) or no glaucoma (n = 50) at an academic institution. The main outcome measure was the difference between the expected and the actual postoperative refraction. RESULTS: Mean intraocular pressure (IOP) increased in trabeculectomy eyes from 8.7 ± 4.2 mm Hg to 10.7 ± 4.0 mm Hg (P < .0001), whereas it decreased in glaucoma control and normal control groups by 2.0 mm Hg (P = .003) and 2.1 mm Hg (P < .00001), respectively, with concurrent decrease in drops in the glaucoma control group (0.76 to 0.23, P < .0001). The difference from expected refractive outcome was -0.36 (more myopic) in trabeculectomy eyes compared with +0.23 (more hyperopic) in nonglaucoma controls and +0.40 in glaucoma controls (P < .0001). The correlation between change in IOP vs extent of refractive surprise was statistically significant (P = .01, r = -0.20). Final visual acuity was not affected by the difference in refractive error. CONCLUSIONS: The refractive surprise correlated to IOP change, with 2 mm Hg rise resulting in a -0.36 diopter shift between predicted and actual refraction. After cataract extraction, IOP decreased in controls and fewer drops were required, but IOP increased in the study group. Factors affecting refractive surprise in cataract surgery after trabeculectomy, especially IOP change and axial length, require further investigation.

A minimally invasive implantable wireless pressure sensor for continuous IOP monitoring.

This paper presents a minimally invasive implantable pressure sensing transponder for continuous wireless monitoring of intraocular pressure (IOP). The transponder is designed to make the implantation surgery simple while still measuring the true IOP through direct hydraulic contact with the intraocular space. Furthermore, when IOP monitoring is complete, the design allows physicians to easily retrieve the transponder. The device consists of three main components: 1) a hypodermic needle (30 gauge) that penetrates the sclera through pars plana and establishes direct access to the vitreous space of the eye; 2) a micromachined capacitive pressure sensor connected to the needle back-end; and 3) a flexible polyimide coil connected to the capacitor forming a parallel LC circuit whose resonant frequency is a function of IOP. Most parts of the sensor sit externally on the sclera and only the needle penetrates inside the vitreous space. In vitro tests show a sensitivity of 15 kHz/mmHg with approximately 1-mmHg resolution. One month in vivo implants in rabbits confirm biocompatibility and functionality of the device.

Biodegradable microfabricated plug-filters for glaucoma drainage devices.

We report on the development of a batch fabricated biodegradable truncated-cone-shaped plug filter to overcome the postoperative hypotony in nonvalved glaucoma drainage devices. Plug filters are composed of biodegradable polymers that disappear once wound healing and bleb formation has progressed past the stage where hypotony from overfiltration may cause complications in the human eye. The biodegradable nature of device eliminates the risks associated with permanent valves that may become blocked or influence the aqueous fluid flow rate in the long term. The plug-filter geometry simplifies its integration with commercial shunts. Aqueous humor outflow regulation is achieved by controlling the diameter of a laser-drilled through-hole. The batch compatible fabrication involves a modified SU-8 molding to achieve truncated-cone-shaped pillars, polydimethylsiloxane micromolding, and hot embossing of biodegradable polymers. The developed plug filter is 500 µm long with base and apex plane diameters of 500 and 300 µm, respectively, and incorporates a laser-drilled through-hole with 44-µm effective diameter in the center.

Correlation between macular thickness and glaucomatous visual fields.

PURPOSE: The purpose of the study was to establish whether predictable structural relationships exist between macular thickness parameters and anatomically related visual field (VF) defects. PATIENTS AND METHODS: The optical coherence tomography (OCT) macular scans and automated VFs of 127 eyes of 127 glaucoma patients were examined retrospectively. The macular scan parameters recorded included the superior inner and outer sectors and the inferior inner and outer sectors. For the VFs, the threshold sensitivities of the central 4×4 points were recorded. The 16 points were grouped into superior outer, superior inner, inferior inner, and inferior outer rows, and the mean of each row was calculated. The OCT macular scan sectors and the VF rows were compared using the Spearman correlation. RESULTS: Statistically significant structural relationships between each macular parameter and its anatomically related VF defect were noted in this study. Highest correlations were found between the inferior outer macular thickness and the superior outer VF region, the inferior inner macular and the superior inner VF region, the superior inner macula and the inferior inner VF region, and the superior outer macula and the inferior outer VF region. CONCLUSIONS: As a predictable and significant structural relationship exists between macular thickness and VF defects, macular scan OCT should be studied further and considered more carefully in the diagnosis and management of glaucoma.

The Ahmed Versus Baerveldt study: design, baseline patient characteristics, and intraoperative complications.

OBJECTIVE: To report the design, baseline patient characteristics, and intraoperative complications of the Ahmed Versus Baerveldt (AVB) Study. DESIGN: Multicenter, randomized, clinical trial. PARTICIPANTS: Patients were recruited from 7 international clinical sites and treated by 10 surgeons between 2005 and 2009. Inclusion criteria required that patients be at least 18 years of age and have uncontrolled glaucoma refractory to medicinal, laser, and surgical therapy. METHODS: Eligible patients were randomized to undergo implantation of an Ahmed-FP7 valve (New World Medical, Inc., Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc., Santa Ana, CA) using standardized surgical technique, to be followed for 5 years. MAIN OUTCOME MEASURES: The primary outcome measure was failure, defined as intraocular pressure (IOP) out of target range (5-18 mmHg with ≥ 20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, additional glaucoma procedures, or loss of light perception. Secondary outcome measures included IOP, medication use, visual acuity, complications, and interventions. RESULTS: A total of 238 patients were enrolled in the study; 124 received the Ahmed-FP7 valve implant and 114 received the Baerveldt-350 implant. The 2 treatment groups did not differ in any baseline characteristics with the exception of sex. The mean age of the study group was 66 ± 16 years, and 55% were women, with a greater proportion in the Baerveldt group (P=0.01). The mean baseline IOP of the study group was 31.4 ± 10.8 on a mean of 3.1 ± 1.0 glaucoma medications. The median Snellen visual acuity was 20/100, mean number of previous laser therapies was 0.9 ± 1.1, and mean number of previous surgeries was 1.7 ± 1.2. Five (4%) patients in the Ahmed group and 4 (4%) patients in the Baerveldt group experienced significant intraoperative complications. CONCLUSIONS: Aqueous drainage devices are being increasingly used for glaucoma refractory to conventional treatment, and the AVB Study compares the 2 most commonly implanted devices. The 2 groups had similar baseline characteristics, and there were a similar number of intraoperative complications for both devices. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Update on the role of alpha-agonists in glaucoma management.

Glaucoma is the second most common cause of world blindness (following cataract) with estimated cases reaching 79.6 million by 2020. Although the etiology of glaucoma is multi-factorial, intraocular pressure (IOP) is the only modifiable factor in glaucoma management proven to alter the natural course of the disease. Among various classes of IOP-lowering medications currently available, alpha-adrenergic receptor agonists are used either as monotherapy, as second-line therapy, or in fixed combination with beta-blockers. Non-selective adrenergic agonists such as epinephrine and dipivefrin are infrequently used today for the treatment of glaucoma or ocular hypertension, and have been replaced by the alpha-2-selective agonists. The use of apraclonidine for IOP reduction in glaucoma or OHT is limited due to a high rate of follicular conjunctivitis. The alpha-2-selective agonist in use today is brimonidine. The brimonidine-purite formulations are preferred to brimonidine-benzalkonium chloride (BAC) formulations due better tolerability while maintaining similar efficacy. Brimonidine is also effective when used in combination with a beta-blocker. Using brimonidine-timolol fixed combination (BTFC) as first-line therapy has an added potential for neuroprotection. This would be a valuable strategy for glaucoma treatment, for patients who are intolerant of prostaglandin analogs, or for patients where prostaglandin analogues are contraindicated as first-line therapy, such as in patients with inflammatory glaucoma.