Ahmad A. Aref

Spectral domain optical coherence tomography in the diagnosis and management of glaucoma.

Spectral domain optical coherence tomography (SD-OCT) is a relatively new imaging technology that is being used for the diagnosis and management of glaucoma. This article presents a review of the specific parameters analyzed by SD-OCT and the diagnostic capability, reproducibility, and limitations of the device. SD-OCT parameters useful for diagnosis of glaucoma include retinal nerve fiber layer analysis, optic nerve head analysis, and ganglion cell complex analysis. These parameters have proven to be at least as equivalent to time-domain technology in terms of diagnostic capability and superior in terms of reproducibility. SD-OCT technology may be limited by signal quality, image artifact, and confounding ocular disease.

Glaucoma management: relative value and place in therapy of available drug treatments

Lowering intraocular pressure (IOP) is the only proven therapeutic intervention for glaucomatous optic neuropathy. Despite advances in laser and microsurgical techniques, medical IOP reduction remains the first-line treatment option for the majority of patients with open-angle glaucoma. Prostaglandin analogs are the most efficacious topical agents and carry a remarkable safety profile. Topical beta-blockers, alpha-agonists, and carbonic anhydrase inhibitors are often employed as adjunctive agents for further IOP control. Newer preserved and nonpreserved formulations are available and appear to be less toxic to the ocular surface. Oral carbonic anhydrase inhibitors, miotic agents, and hyperosmotics are infrequently used due to a host of potentially serious adverse events. Medical therapies on the horizon include rho-kinase inhibitors, neuroprotective interventions, and gene therapies.

Management of immediate and sustained intraocular pressure rise associated with intravitreal antivascular endothelial growth factor injection therapy.

Purpose of review To summarize the findings of recent reports of short-term and sustained intraocular pressure (IOP) rise associated with intravitreal antivascular endothelial growth factor (VEGF) injections and to guide the management of this infrequent complication. Recent findings Short-term increases in IOP are common immediately after intravitreal anti-VEGF injection. IOP takes longer to reach a safe level in patients with a history of glaucoma or ocular hypertension. Preinjection medicinal therapy and ocular decompression therapy may blunt this short-term IOP rise. Sustained increases in IOP are relatively infrequent, but are likely to necessitate intervention for IOP-lowering. A ‘pro re nata’ (PRN) injection protocol may obviate the need for intervention. The pathophysiology of sustained IOP rise is poorly understood, but may relate to repackaging processes undertaken by the pharmacies that compound these agents. Summary Treating physicians should be aware of the potential for short-term and sustained IOP rise associated with intravitreal anti-VEGF injection therapy. Considerations for management include prophylactic IOP-lowering with medicinal therapy and/or preinjection ocular decompression for patients with a history of glaucoma or ocular hypertension and switching to a ‘PRN’ injection protocol in patients suffering a sustained rise in IOP.

Diagnostic specificities of retinal nerve fiber layer, optic nerve head, and macular ganglion cell-inner plexiform layer measurements in myopic eyes

Purpose:To evaluate and compare the diagnostic specificities of peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell-inner plexiform layer (GC-IPL) thickness, and optic nerve head (ONH) measurements in nonglaucomatous myopic individuals. Methods:In a prospective, cross-sectional study, participants underwent a complete ophthalmic examination, a screening automated visual field test, and axial length measurement. The study eye then underwent optic nerve head and macular scanning using spectral-domain optical coherence tomography (OCT) instrumentation to determine RNFL thickness, GC-IPL thickness, and ONH measurements. False-positive rates for each of the OCT-derived parameters, using predefined criteria for an abnormal test, were calculated. Comparative analysis was performed using the McNemar test. Results:Data from 43 eligible subjects were analyzed. The mean age was 30±6.8 years (range, 22 to 50 y) with an average axial length of 25.26±1.21 mm (range, 23.06 to 29.07 mm) and mean spherical equivalent of −4.50±1.93 D (range, −1.00 to −9.00 D). The false-positive rate was higher when using RNFL parameters compared with both ONH (47% vs. 7%, respectively; P<0.001) and GC-IPL (47% vs. 26%, respectively; P=0.049) parameters. The false-positive rate was higher when using GC-IPL parameters, compared with ONH parameters (26% vs. 7%, respectively; P=0.039). Conclusions:Caution should be exercised when relying on OCT-derived RNFL and GC-IPL thickness values to diagnose glaucoma in myopic individuals. OCT-derived ONH parameters perform better than RNFL and GC-IPL parameters and may increase diagnostic specificity in this population.

Management of macular edema secondary to branch retinal vein occlusion: an evidence-based update

Retinal vein occlusions are common retinal vascular disorders with the potential for significant vision-related morbidity. Retinal vein occlusions are classified as either branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO), or hemiretinal vein occlusion (HRVO) based on the specific occlusion site. The most common cause of decreased vision in patients afflicted with BRVO is the accumulation of fluid within the macula (macular edema). The Branch Vein Occlusion Study (BVOS) demonstrated the efficacy of grid laser photocoagulation in the treatment of BRVO-related macular edema. After publication of that report, grid laser became the standard of care for decreased vision due to BRVO-associated macular edema in patients similar to those enrolled in the BVOS. However, several recent major randomized, controlled clinical trials have investigated new therapeutic modalities for the treatment of decreased vision due to macular edema secondary to BRVO. This article aims to provide insight into current evidence-based approaches to management of macular edema secondary to BRVO. A companion article reviews approaches for management of macular edema secondary to CRVO.

Dietary factors and the risk of glaucoma: a review.

Glaucoma is an optic neuropathy characterized by a progressive typical pattern of optic neurodegeneration and visual field loss. A relatively high proportion of glauctomatous individuals admit to interest in dietary modification in an attempt to manage their disease. Heavy caffeine consumption appears to have a transient effect on increasing intraocular pressure (IOP). This effect may be clinically insignificant for nonglaucomatous individuals, but the association warrants clinical consideration in those with the disease. Studies investigating the relationship between self-reported antioxidant intake and risk of glaucomatous disease have reported conflicting results. Preliminary studies investigating the relationship between self-reported glaucoma diagnosis and consumption of the oxidants calcium and iron suggest a possible relationship indicating increased risk of the disease with increased consumption of these dietary factors. Initial reports in the literature suggest a potential role for dietary modification in the treatment of glaucomatous optic neuropathy. Further study, with randomized controlled trials, may be necessary to further characterize these relationships.

Incidence, Risk Factors, and Timing of Elevated Intraocular Pressure After Intravitreal Triamcinolone Acetonide Injection for Macular Edema Secondary to Retinal Vein Occlusion: SCORE Study Report 15

IMPORTANCE The Standard of Care vs Corticosteroid for Retinal Vein Occlusion (SCORE) Study showed that intravitreal triamcinolone acetonide (IVTA) is effective at reducing macular edema and improving visual acuity in participants with retinal vein occlusion. Secondary analysis of the incidence, risk factors, and timing of intraocular pressure (IOP) elevation occurring after IVTA provides guidance for clinical decision making and management of patients treated with IVTA. OBJECTIVE To investigate the incidence, risk factors, and time course of IOP elevation in participants in the SCORE Study. DESIGN, SETTING, AND PARTICIPANTS Secondary analysis conducted from August through December 2014 of a prospective, randomized clinical trial featuring an evaluable population conducted at 75 clinical sites. Six hundred eighty-two patients with macular edema secondary to retinal vein occlusion were enrolled in the study. The SCORE Study enrollment period ran from November 4, 2004, to February 29, 2008, with participant follow-up ending February 28, 2009. INTERVENTIONS Study participants were randomized to standard of care, 1 mg of IVTA, or 4 mg of IVTA therapy and followed up for a mean (SD) of 24.7 (10.3) months. MAIN OUTCOMES AND MEASURES Intraocular pressure elevation greater than 10 mm Hg from baseline. RESULTS Kaplan-Meier incidences of IOP elevation greater than 10 mm Hg from baseline at 36 months were 0.02 (95% CI, 0.01-0.06), 0.09 (95% CI, 0.05-0.14), and 0.45 (95% CI, 0.38-0.53) in the standard of care, 1-mg IVTA, and 4-mg IVTA groups, respectively. The rates of IOP-related events were higher for the 4-mg IVTA group compared with the other groups (P ≤ .001 for main outcome measure). Younger age, 4-mg IVTA vs 1-mg IVTA treatment, and higher baseline IOP were found to confer greater risk for IOP-related events (P < .05 for all). The median number of days from time of first injection to IOP elevation greater than 10 mm Hg from baseline was 34.0 and 52.5 days in participants treated with 1-mg and 4-mg IVTA, respectively. CONCLUSIONS AND RELEVANCE Intravitreal triamcinolone acetonide injection therapy, in particular the 4-mg dose, is associated with an increased risk for IOP elevation. The risk factors for an IOP-related event include higher treatment dose, younger age, and higher baseline IOP. Intraocular pressure-related events may take several months from the time of first IVTA injection to occur. Clinicians should be mindful of these risk factors when assessing the risks and benefits of IVTA therapy and also of the need for long-term follow-up of participants at risk for this complication. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00105027.

Management of macular edema secondary to central retinal vein occlusion: an evidence-based

Retinal vein occlusions are common retinal vascular disorders with the potential for significant vision-related morbidity. Retinal vein occlusions are classified as either branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO), or hemiretinal vein occlusion (HRVO) based on the specific occlusion site. Decreased vision in patients afflicted with CRVO may result from retinal ischemia and/or the accumulation of fluid within the center of the retina (macular edema). The Central Vein Occlusion Study (CVOS) Group demonstrated that grid laser photocoagulation is not an effective treatment for decreased vision due to CRVO-related macular edema. Since publication of that report, the standard of care for patients with decreased vision due to CRVO-associated macular edema was observation. However, in the past 5 years, several major randomized controlled clinical trials have investigated new therapeutic modalities for the treatment of macular edema secondary to CRVO. This article aims to provide insight into current evidencebased approaches to the management of macular edema secondary to CRVO. A companion article reviews approaches for the management of macular edema secondary to BRVO.

Outcomes of pars plana glaucoma drainage implant in Boston type 1 keratoprosthesis surgery.

Purpose:Glaucoma drainage implantation in conjunction with Boston Type 1 Keratoprosthesis placement is a surgical option in controlling postoperative glaucoma. The purpose of this study is to report outcomes of combined pars plana vitrectomy and glaucoma drainage implantation with corneal patch graft in Boston Type 1 Keratoprosthesis patients. Patients and Methods:A retrospective review of patients who underwent pars plana glaucoma drainage implantation in combination with Boston Type 1 Keratoprosthesis was performed. Preoperative and postoperative parameters collected and analyzed included: visual acuity, intraocular pressure, number of glaucoma medications to achieve intraocular pressure control, bandage contact lens fit, and postoperative complications. Results:Twenty eyes of 20 patients were identified; 95% had preoperative diagnosis of glaucoma, utilizing on an average 2.5 medications with an average intraocular pressure of 19.8 mm Hg (±6.3 mm Hg; range, 9 to 32.8 mm Hg). After placement of the pars plana glaucoma drainage implant, an average intraocular pressure of 19 mm Hg (±7.0 mm Hg; range, 8 to 30 mm Hg) by scleral pneumotonometry was achieved and 85% were deemed to have normal pressures by digital palpation. An average of 2.1 intraocular pressure-lowering medications were required on last follow-up. Average follow-up was 31.6 months (±17.4 mo; range, 12.3 to 71.6 mo). Two eyes required glaucoma drainage implant explantation: one eye due to endophthalmitis from a nonhealing corneal ulcer and the other eye due to corneal melt. None of our patients experienced conjunctival erosion over a pars plana positioned glaucoma drainage implant or tube. Conclusions:For the long-term management of glaucoma in keratoprosthesis patients, a posteriorly placed pars plana glaucoma drainage implant with corneal patch graft in conjunction with keratoprosthesis has a low risk of erosion and postoperative complications.

What happens to glaucoma patients during sleep

Purpose of review To summarize the findings of the recent reports on nighttime events that may lead to the development or progression of glaucomatous optic neuropathy. Recent findings Peak intraocular pressure (IOP) likely occurs at night because of the head and body positions assumed during sleep. Sleeping in a 30° head-up position leads to IOP lowering during this time period. Laser trabeculoplasty and glaucoma-filtering surgery are efficacious in controlling IOP over a 24-h period, although most medical therapies may be inadequate. The Sensimed Triggerfish (Sensimed AG, Lausanne, Switzerland) device is capable of recording IOP fluctuations over a 24-h period. A nocturnal increase in IOP and decrease in blood pressure leads to lower ocular perfusion pressure (OPP), which may significantly increase the risk of glaucomatous visual field progression. Prospective case–control studies report a positive association between obstructive sleep apnea (OSA) and glaucoma; larger, retrospective cohort studies report no association. Summary Several nighttime events including increased IOP, decreased OPP, and possibly OSA contribute to the development and progression of glaucomatous optic neuropathy. These events may explain the occurrence and progression of glaucomatous disease in the setting of seemingly controlled office-measured IOP.