Robert F. See

Systemic pharmacokinetics following intravitreal injections of ranibizumab, bevacizumab or aflibercept in patients with neovascular AMD

Background Data comparing systemic exposure and systemic vascular endothelial growth factor (VEGF) suppression of ranibizumab, bevacizumab and aflibercept following intravitreal injection are lacking. Methods Fifty-six patients with wet age-related macular degeneration received intravitreal ranibizumab (0.5 mg), bevacizumab (1.25 mg), or aflibercept (2.0 mg). Serum pharmacokinetics and plasma free VEGF were evaluated after the first and third injections. Results Following the first dose, systemic exposure to aflibercept was 5-, 37-, and 9-fold higher than ranibizumab, whereas, bevacizumab was 9-, 310-, and 35-fold higher than ranibizumab, based on geometric mean ratio of peak and trough concentrations and area under the curve, respectively. The third dose showed accumulation of bevacizumab and aflibercept but not ranibizumab. Aflibercept substantially suppressed plasma free VEGF, with mean levels below lower limit of quantitation (10 pg/mL) as early as 3 h postdose until ≥7 days postdose. Mean free (unbound) VEGF levels with ranibizumab were largely unchanged, with mean trough level of 14.4 pg/mL compared with baseline of 17 pg/mL. Conclusions There are notable differences in systemic pharmacokinetics and pharmacodynamics among anti-VEGF treatments after intravitreal administration. All three agents rapidly moved into the bloodstream, but ranibizumab very quickly cleared, whereas bevacizumab and aflibercept demonstrated greater systemic exposure and produced a marked reduction in plasma free VEGF. Trial registration number NCT02118831.

Ranibizumab for the Treatment of Macular Edema Associated with Perfused Central Retinal Vein Occlusions

PURPOSE Assessment of biological effect, visual acuity changes, and safety of intravitreal (IVT) ranibizumab in patients with macular edema associated with perfused central retinal vein occlusion (CRVO). DESIGN Ongoing, prospective, open-label, single-center, uncontrolled study. PARTICIPANTS Ten adult patients with macular edema associated with perfused CRVO. METHODS Patients were randomly assigned to receive 3 monthly IVT injections of either 0.3 or 0.5 mg ranibizumab (n = 5 at each dose). Additional injections were administered quarterly as needed over the ensuing 21 months at the physicians discretion for recurrent or persistent macular edema. MAIN OUTCOME MEASURES The predetermined primary endpoint was the percentage of patients gaining >or=15 letters of best-corrected Early Treatment of Diabetic Retinopathy Study visual acuity (BCVA). The secondary endpoints include the mean change in BCVA and central retinal thickness (CRT) measured by optical coherence tomography, the rate of progression to ischemic CRVO, extent of intraocular hemorrhage, retinal vein diameter, optic nerve head swelling, and the incidence and severity of ocular and nonocular adverse events. RESULTS After 3, 6, and 9 months of follow-up, 40%, 10%, and 30% of patients, respectively, gained >or=15 letters in BCVA; mean BCVA improved by 12+/-20 letters, 3+/-21 letters, and 1+/-24 letters, respectively, compared with baseline; CRT showed a mean decrease of 272+/-244 microm, 88+/-178 microm, and 119+/-153 microm, compared with baseline. No significant differences were observed between the 0.3- and 0.5-mg doses. Most patients experienced decreases in the extent of retinal hemorrhage, retinal vein diameter, and optic nerve head swelling at months 3 and 6 compared with baseline. No patients progressed to ischemic CRVO or experienced a severe adverse event that was attributed to ranibizumab. CONCLUSIONS Ranibizumab is generally well-tolerated and may improve BCVA and decrease CRT. The improvements in BCVA and CRT observed during the initial monthly injection period (0 to 3 months) were possibly lost to the recurrence of macular edema in between ranibizumab injection during the quarterly treatments (3 to 9 months). The extent of retinal hemorrhage, retinal vein diameter, and nerve swelling continued to normalize for most of the patients from baseline to 6 months. Follow-up is ongoing, and alternative dosing regimens are being evaluated.

Ab Interno Trabeculectomy: Development of a Novel Device (trabectome™) and Surgery for Open-angle Glaucoma

Purpose:To design an instrument to selectively remove trabecular meshwork and Schlemms canal inner wall (SCIW), and demonstrate its effectiveness by histologic analysis of treated cadaveric human tissue. Methods:The design parameters of the instrument were the ability to permanently remove a segment of trabecular meshwork and Schlemms canal inner wall without causing damage to surrounding tissue, and to allow use with standard anterior segment surgical techniques and equipment via an ab interno approach. Treatment was applied to 20 segments of human corneoscleral rims. The treated areas were examined using a confocal microscope and compared with matching areas in untreated controls and simulated goniotomy. Results:The resultant instrument system surgically removes the trabecular meshwork and Schlemms canal inner wall from an anterior chamber approach. It consists of a disposable surgical handpiece with irrigation, aspiration, and electrocautery to focally ablate the target tissues. The attached console includes a high-frequency (550 KHz) electrosurgical generator and irrigation/aspiration controlled by a foot pedal. Histologic examination of specimens treated with the Trabectome™ displayed disruption of the trabecular meshwork and Schlemms canal inner wall without damage to surrounding structures. The specimens treated by simulated goniotomy displayed significant damage to the outer wall of Schlemms canal and the surrounding sclera. The controls showed no disruption or damage to any tissues. Conclusions:The Trabectome™ system is designed for performing trabeculectomy via an ab interno approach. It successfully removed sections of trabecular meshwork and Schlemms canal inner wall with less injury to the adjacent tissue compared with goniotomy knife in vitro. Theoretically, this procedure should provide direct access of aqueous humor to Schlemms canal.

Cytomegalovirus retinitis in the era of combined highly active antiretroviral therapy

Advancements in antiretroviral therapy have changed the way we view and treat cytomegalovirus retinitis (CMVR). At one time the diagnosis of CMVR necessitated that most patients undergo daily intravenous infusions of anti-CMV agents. Today, after the restoration of their immune systems, they are able to stop maintenance anti-CMV therapy. HAART failure, resistant strains of CMV, and immune recovery uveitis are growing challenges.

The effects of atorvastatin in experimental autoimmune uveitis

Aim: To investigate the effect of atorvastatin (Lipitor), a commonly used drug for dyslipidaemia in experimental autoimmune uveitis (EAU). Methods: 48 B10-RIII mice were immunised with human interphotoreceptor retinoid binding protein (IRBP) peptide p161–180. They were divided into three groups of 16 each and treated orally once daily for 14 days; group one received phosphate buffered saline (control group), group two received 1 mg/kg of atorvastatin (low dose group), and group three received 10 mg/kg (high dose). On day 14 lymph nodes, spleens, and right eyes were harvested. RNA was extracted from lymph nodes for RNase protection assay (RPA) to determine proinflammatory (IL-1α and IL-1β), Th1 (TNF-α, IL-2, IL-12), and Th2 (IL-4, IL-5, and IL-10) cytokine levels. Protein was extracted from spleens for western blot to detect the expression of phosphorylated signal transducer and activator of transcription (STAT) 4 and STAT6. The severity of inflammation in enucleated eyes was graded by a masked observer. Paired t test was performed for the mean difference in histological scoring between treated groups and the immunised control group. Results: Surprisingly, atorvastatin did not modulate the immune response. The proinflammatory cytokines, IL-1α and IL-1β, and Th1 cytokines, TNF-α and IL-2, were upregulated equally in control and atorvastatin treated groups. IL-12 and Th2 cytokines were not upregulated in all three groups. Western blot analysis showed high levels of phosphorylated STAT4, but not STAT6 protein in the control and atorvastatin treated groups. Mean differences in histological scoring between treated groups and the immunised control group were not statistically significant. Conclusions: Atorvastatin treatment had no effect on Th1 and Th2 cytokine transcription. Although histological grading suggested mildly decreased inflammation in the high dose treated group, the equivalence of cytokine expression in all groups suggests that the statins may not modulate IRBP induced uveoretinitis.

Conjunctival ulcers in Behçet's disease

PURPOSE To describe the occurrence of conjunctival ulcers as a manifestation of Behçets disease. DESIGN Retrospective, noncomparative, interventional case series with histopathologic correlation. METHODS Six patients who fulfilled the diagnostic criteria for Behçets disease and presented with painful conjunctival ulcers were included in the study. Three of these ulcers were biopsied and studied histologically and immunohistochemically. The lesions were treated with topical or subconjunctival injection of corticosteroids and, in one case, with oral indomethacin. RESULTS Although all six patients fulfilled the diagnostic criteria for Behçets disease, two developed uveitis and other signs of Behçets disease only months to years after the appearance of the conjunctival ulcers. The 3- to 5-mm, round to oval ulcers were located in the limbal and/or bulbar conjunctiva. Histopathology revealed disrupted epithelium, infiltration of both acute and chronic inflammatory cells, and high endothelial venules. Immunohistochemical analysis of the infiltrating lymphocytes revealed primarily T-cell populations admixed with several B cells and CD68-positive histiocytes. After treatment, the conjunctival lesions invariably healed without scarring. CONCLUSIONS In addition to the oral and genital ulceration, ulcers can also be found in the conjunctiva of patients with Behçets disease. Although this is a rare clinical sign, when accompanied by uveitis or orogenital ulcers, it may suggest a diagnosis of Behçets disease.

Orbitotemporal Neurofibromatosis: Classification and Treatment ∗

Purpose: To review the clinical findings in orbitotemporal neurofibromatosis and discuss treatment options. Clinical features, histopathologic characteristics, and treatment options are reviewed. Methods: A Medline literature search from 1966 to 2004 was performed, using the key words: orbitotemporal neurofibromatosis, orbitopalpebral neurofibromatosis, orbitofacial neurofibromatosis, cranio-orbital neurofibromatosis, and cranio-orbital-temporal neurofibromatosis, and the pertinent literature was reviewed. Additionally, our experience with two patients is reported. The surgical procedures are discussed. Conclusion: The management of orbitotemporal neurofibromatosis is challenging. The planned surgical approach and extent of resection depend on the severity of the orbital soft tissue and bony involvement and on the visual potential. Ultimately, orbital exenteration may be needed for rehabilitation and cosmesis.

Systemic Pharmacokinetics And Pharmacodynamics Of Intravitreal Aflibercept, Bevacizumab, And Ranibizumab

Purpose: To evaluate the systemic pharmacokinetics (PKs) of aflibercept, bevacizumab, and ranibizumab in patients with neovascular age-related macular degeneration (AMD), diabetic macular edema (DME), or retinal vein occlusion (RVO). Methods: Prospective, open-label, nonrandomized clinical trial of patients with AMD, DME, or RVO who were antivascular endothelial growth factor (VEGF) naïve or had not received anti-VEGF for ≥4 months. Patients received 3 monthly intravitreal injections of aflibercept 2.0 mg, bevacizumab 1.25 mg, or ranibizumab (0.5 mg for AMD/RVO, 0.3 mg for DME). The main outcome measures were serum PKs and plasma free-VEGF concentrations after the first and third injections. Results: A total of 151 patients were included. In AMD/DME/RVO, systemic exposure to each drug was highest with bevacizumab, then aflibercept, and lowest with ranibizumab. Ranibizumab cleared from the bloodstream more quickly than bevacizumab or aflibercept. Aflibercept treatment resulted in the greatest reductions in plasma free-VEGF relative to baseline levels, whereas ranibizumab treatment resulted in the smallest decreases in plasma free-VEGF. Conclusion: The three anti-VEGF treatments examined in this analysis demonstrated notable differences in systemic PKs. Generally, the reduction in plasma free-VEGF levels correlated with elevated levels of circulating anti-VEGF agents, with the reduction in free-VEGF levels greatest with aflibercept and least with ranibizumab.

Outer retina reflectivity changes on sd-oct after intravitreal ocriplasmin for vitreomacular traction and macular hole.

Purpose: To report initial experience with intravitreal ocriplasmin (IVO) and to describe outer retina reflectivity changes observed on spectral domain optical coherence tomography (SD-OCT) after IVO injection in patients with vitreomacular traction (VMT) with or without macular holes (MHs). Methods: A consecutive retrospective review of patients with VMT and MH who were treated with IVO was performed. Patients underwent complete ophthalmic evaluation, including nonstandardized Snellen visual acuity testing, and SD-OCT at baseline and follow-up visits. Results: A total of 23 patients who received IVO for VMT and/or MH were included for analysis. Patient age ranged from 53 years to 93 years with a mean of 74 years. The mean follow-up was 174 days (range: 20–291 days). Vitreomacular traction release at Day 30 after IVO was achieved in 11 of 23 patients (47.82%), at an average of 14.54 days (range: 1–30 days) after treatment. The mean visual acuity improved from 0.50 to 0.38. At presentation, eight patients had MH associated with VMT. Closure of the MH with ocriplasmin was achieved in two patients, and six patients underwent pars plana vitrectomy for MH repair. Ten of 23 patients (43.47%) presented with changes in the outer retina reflectivity on SD-OCT after IVO, 4 patients of this group experienced a decrease in visual acuity. In 7 of these 10 patients (70%), VMT release was documented on OCT by Day 30 postinjection compared with 4 of 13 patients (30.76%) without outer retina changes post-IVO. Normalization of the outer retina reflectivity was achieved in all cases. Conclusion: In this case series of VMT/MH patients treated with ocriplasmin, changes in the SD-OCT outer retina reflectivity were relatively common. Within weeks, the outer retinal reflectivity on SD-OCT improved, as did the visual acuity. Further studies to investigate the association between outer retina reflectivity changes with the use of IVO and long-term visual acuity outcomes are warranted.

Intravitreal Ranibizumab For Macular Edema Secondary To Central Retinal Vein Occlusion

Purpose: To evaluate the safety and efficacy of intravitreal ranibizumab for macular edema secondary to central retinal vein occlusion. Methods: Patients with macular edema secondary to perfused central retinal vein occlusion were enrolled in this ongoing, prospective, open-label study. Treatment was initiated with monthly intravitreal ranibizumab for 3 months. In the first year, additional injections were administered for edema in quarterly intervals as needed (PRN) for Cohort 1 (n = 10) and monthly PRN for Cohort 2 (n = 10). In the second year of treatments, all patients received monthly PRN treatment. Early Treatment Diabetic Retinopathy Study best-corrected visual acuity, central retinal thickness, fundus photographs, and fluorescein angiograms were evaluated, and the incidence and severity of adverse events were documented. Results: Mean change in best-corrected visual acuity and central retinal thickness improved during the induction phase in both groups. During the remainder of the first year for Cohort 1, initial gains were lost during quarterly treatment but returned with monthly PRN treatment in the second year. For Cohort 2, improvement in best-corrected visual acuity and central retinal thickness from the induction phase was maintained through Month 24. Nineteen of 20 patients experienced a reduction in intraretinal hemorrhage, optic nerve swelling, and/or venous diameter after treatment. One myocardial infarction, one cerebrovascular accident, and no serious ocular adverse events were reported. Iris neovascularization was developed in none of the eyes. Conclusion: Ranibizumab was well tolerated and associated with a greater reduction in macular edema and improvement in visual acuity in the monthly PRN regimen compared with quarterly treatment. Vision lost during the quarterly PRN injection intervals in the first year of Cohort 1 could be regained by switching to monthly PRN dosing.