Two-year results for ranibizumab for radiation retinopathy (RRR): a randomized, prospective trial.

PURPOSE: To assess the efficacy of a treat-and-extend strategy with intravitreal ranibizumab for radiation-related macular edema. METHODS: Forty eyes with radiation-induced macular edema and decreased visual acuity were enrolled in the phase IIb, prospective clinical trial and randomized into 3 cohorts: (A) monthly ranibizumab, (B) monthly ranibizumab with targeted retinal photocoagulation (TRP), or (C) as-needed ranibizumab and TRP. In year 2, all subjects entered a treat-and-extend protocol for ranibizumab. The primary outcome measure was mean change in early treatment diabetic retinopathy study (ETDRS) best-corrected visual acuity (BCVA) from baseline. RESULTS: Through year 1, the mean change in ETDRS BCVA was significantly different between the three cohorts (p < 0.001); cohort A saw the largest gain with + 4.0 letters. Significant anatomic improvements were also seen in all cohorts. Comparatively, through year 2, cohorts A, B, and C had a mean change in ETDRS BCVA of - 1.9, - 3.9, and + 1.3 letters, respectively; additionally, no significant differences were found in absolute ETDRS BCVA across time (ANOVA, p = 0.123). Overall, 90% of eyes maintained VA 20/200 or better and 33.3% of subjects gained at least one line of vision. There were no significant differences in mean central macular thickness for any cohort compared to baseline (p = 0.09). The presence of retinal hemorrhage and intraretinal exudates stayed consistent from year 1 to year 2 for all cohorts. CONCLUSIONS: Among eyes with radiation-related macular edema, a treat-and-extend regimen with ranibizumab may not result in as many visual and anatomic improvements as monthly injections. However, treat-and-extend still may prevent serious visual complications compared to historical controls. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02222610.

Randomized Trial of Monthly Versus As-Needed Intravitreal Ranibizumab for Radiation Retinopathy-Related Macular Edema: 1-Year Outcomes.

PURPOSE: To assess efficacy of intravitreal ranibizumab injections and targeted panretinal photocoagulation (TRP) for radiation retinopathy-related macular edema. DESIGN: Phase IIb, prospective, randomized clinical trial. METHODS: Setting: Multicenter. SUBJECTS: Forty eyes in 40 treatment-naïve patients with radiation-induced macular edema and a resulting decrease in visual acuity ranging between 20/25 and 20/400 (Snellen equivalent). INTERVENTION: Patients either received intravitreal 0.5 mg ranibizumab monthly, monthly ranibizumab with TRP, or 3 monthly ranibizumab (loading doses) followed by as-needed (PRN) injections and TRP. After week 52, all subjects entered a treat-and-extend protocol for ranibizumab. MainOutcomeMeasures: Mean Early Treatment Diabetic Maculopathy Study (ETDRS) BCVA change from baseline. RESULTS: Mean patient age was 57 years (range, 22-80 years), ETDRS BCVA was 56.7 letters (20/74 Snellen equivalent), and central macular thickness (CMT) was 423 µm (range, 183-826 µm). Thirty-seven patients completed the month 12 visit (92.5%), at which time the change in mean BCVA was +4.0 letters, -1.9 letters, and +0.9 letters in the monthly, monthly plus laser, and PRN plus laser cohorts, respectively. There was a significant difference in mean BCVA at 1 year among all 3 cohorts (P < .001), as well as between cohorts in pairwise comparisons, with the most significant gains in the monthly group. A total of 82.5% of the patients retained visual acuity of 20/200 or better, and 20.0% improved 10 or more ETDRS letters. CONCLUSIONS: Ranibizumab may improve vision and anatomy in patients with radiation retinopathy-related macular edema and prevent vision loss through 48 weeks of therapy. Monthly injections were more effective than as-needed approach, and the addition of TRP yielded no therapeutic benefits.

Intra-arterial Chemotherapy for Adult Onset Retinoblastoma in a 32-Year-Old Man.

A 32-year-old man with active unilateral group D retinoblastoma that was recurrent following external beam radiotherapy was treated with intra-arterial chemotherapy, leading to tumor regression. Additional plaque radiotherapy and intravitreal chemotherapy were required for complete control. Final visual acuity was 20/40. In selected cases, adult-onset retinoblastoma can be managed with intra-arterial chemotherapy. [J Pediatr Ophthalmol Strabismus. 2016;53:e43-e46.].

Reduction of adult hippocampal neurogenesis confers vulnerability in an animal model of cocaine addiction.

Drugs of abuse dynamically regulate adult neurogenesis, which appears important for some types of learning and memory. Interestingly, a major site of adult neurogenesis, the hippocampus, is important in the formation of drug-context associations and in the mediation of drug-taking and drug-seeking behaviors in animal models of addiction. Correlative evidence suggests an inverse relationship between hippocampal neurogenesis and drug-taking or drug-seeking behaviors, but the lack of a causative link has made the relationship between adult-generated neurons and addiction unclear. We used rat intravenous cocaine self-administration in rodents, a clinically relevant animal model of addiction, to test the hypothesis that suppression of adult hippocampal neurogenesis enhances vulnerability to addiction and relapse. Suppression of adult hippocampal neurogenesis via cranial irradiation before drug-taking significantly increased cocaine self-administration on both fixed-ratio and progressive-ratio schedules, as well as induced a vertical shift in the dose-response curve. This was not a general enhancement of learning, motivation, or locomotion, because sucrose self-administration and locomotor activity were unchanged in irradiated rats. Suppression of adult hippocampal neurogenesis after drug-taking significantly enhanced resistance to extinction of drug-seeking behavior. These studies identify reduced adult hippocampal neurogenesis as a novel risk factor for addiction-related behaviors in an animal model of cocaine addiction. Furthermore, they suggest that therapeutics to specifically increase or stabilize adult hippocampal neurogenesis could aid in preventing initial addiction as well as future relapse.

A simple gas chromatography-mass spectrometry procedure for the simultaneous determination of buprenorphine and norbuprenorphine in human urine.

With the increasing use of buprenorphine in treatment of opiate addiction and pain management, it is important that laboratories be able to assess patient compliance. The presented procedure is simple, efficient, and employs gas chromatography-mass spectrometry (GC-MS) technology available to most laboratories. The specimen is hydrolyzed with beta-glucuronidase prior to liquid-liquid extraction at a basic pH. The evaporated extract is derivatized to form the tertiary-butyl-dimethyl-silyl derivatives of buprenorphine and norbuprenorphine prior to analysis by GC-MS in the electron impact mode. Confirmation of the analytes is based on comparing the ion abundance ratios of the analytes to those of a contemporaneously analyzed standard. The qualitative ion abundance ratios are required to be within 20% of those of the standard for acceptance. Quantification is based on the ion ratios of the analytes to those of their corresponding deuterated analogues. Linearity was obtained for buprenorphine in the range of 1 to 2000 microg/L with a correlation coefficient (R) exceeding 0.999 and for norbuprenorphine from 1 to 1000 microg/L with R exceeding 0.997. Percent recoveries for the buprenorphine and norbuprenorphine were 71% and 75%, respectively. It was found that the recovery of norbuprenorphine could be enhanced to 100% by a simple "salting-out" modification to the procedure.

False positive acetaminophen concentrations in patients with liver injury.

BACKGROUND: Acetaminophen toxicity is the most common form of acute liver failure in the U.S. After acetaminophen overdoses, quantitation of plasma acetaminophen can aid in predicting severity of injury. However, recent case reports have suggested that acetaminophen concentrations may be falsely increased in the presence of hyperbilirubinemia. METHODS: We tested sera obtained from 43 patients with acute liver failure, mostly unrelated to acetaminophen, utilizing 6 different acetaminophen quantitation systems to determine the significance of this effect. In 36 of the 43 samples with bilirubin concentrations ranging from 1.0-61.5 mg/dl no acetaminophen was detectable by gas chromatography-mass spectroscopy. These 36 samples were then utilized to test the performance characteristics of 2 immunoassay and 4 enzymatic-colorimetric methods. RESULTS: Three of four colorimetric methods demonstrated 'detectable' values for acetaminophen in from 4 to 27 of the 36 negative samples, low concentration positive values being observed when serum bilirubin concentrations exceeded 10 mg/dl. By contrast, the 2 immunoassay methods (EMIT, FPIA) were virtually unaffected. The false positive values obtained were, in general, proportional to the quantity of bilirubin in the sample. However, prepared samples of normal human serum with added bilirubin showed a dose-response curve for only one of the 4 colorimetric assays. CONCLUSIONS: False positive acetaminophen tests may result when enzymatic-colorimetric assays are used, most commonly with bilirubin concentrations >10 mg/dl, leading to potential clinical errors in this setting. Bilirubin (or possibly other substances in acute liver failure sera) appears to affect the reliable measurement of acetaminophen, particularly with enzymatic-colorimetric assays.

Vision loss associated with the use and removal of intraocular silicone oil.

PURPOSE: To describe vision loss associated with the use or removal of silicone oil retinal tamponade. METHODS: Records were reviewed of all patients with a decrease in visual acuity of at least 3 Snellen lines from best acuity with 5000 centistoke silicone oil in place or after removal of silicone oil at a single retina-only practice between 1996 and 2006. RESULTS: Nine patients (6 men, 3 women) with a mean age of 48 years (range, 16-61) met study inclusion criteria. Seven patients lost at least three Snellen lines of vision while the silicone oil was in place. Four patients had late modest improvements in acuity when compared to their final recorded Snellen vision before silicone oil removal, however no patients exhibited visual improvement when comparing their final recorded visual acuities after oil removal with best recorded acuities under oil tamponade. Loss of the foveal depression was a consistent feature on optical coherence tomography. CONCLUSIONS: Vision loss is a possible complication of silicone oil use and removal. Late visual improvement may occur in some patients. Further research is warranted to elucidate the mechanism(s) of vision loss associated with the use or removal of silicone oil.

Addiction-related alterations in D1 and D2 dopamine receptor behavioral responses following chronic cocaine self-administration.

The cocaine-addicted phenotype can be modeled in rats based on individual differences in preferred levels of cocaine intake and a propensity for relapse in withdrawal. These cocaine-taking and -seeking behaviors are strongly but differentially regulated by postsynaptic D1 and D2 receptors in the mesolimbic dopamine system. Thus, we determined whether addiction-related differences in cocaine self-administration would be related to differential sensitivity in functional D1 and D2 receptor responses. Using a population of 40 outbred Sprague-Dawley rats trained to self-administer cocaine for 3 weeks, we found that animals with higher preferred levels of cocaine intake exhibited a vertical and rightward shift in the self-administration dose-response function, and were more resistant to extinction from cocaine self-administration, similar to phenotypic changes reported in other models of cocaine addiction. After 3 weeks of withdrawal from cocaine self-administration, high intake rats were subsensitive to the ability of the D1 agonist SKF 81297 to inhibit cocaine-seeking behavior elicited by cocaine priming, but supersensitive to cocaine seeking triggered by the D2 agonist quinpirole, when compared to low intake rats. Additionally, high intake rats developed profound increases in locomotor responses to D2 receptor challenge from early to late withdrawal times, whereas low intake rats developed increased responsiveness to D1 receptor challenge. In a second experiment, responses to the mixed D1/D2 agonist apomorphine and the NMDA glutamate receptor antagonist MK-801 failed to differ between low and high intake rats. These findings suggest that cocaine addiction is related specifically to differential alterations in functional D1 and D2 receptors and their ability to modulate cocaine-seeking behavior.

Complications of general anesthesia using nitrous oxide in eyes with preexisting gas bubbles.

PURPOSE: To present the visual and anatomical outcomes for patients with intraocular gas placed during vitreoretinal surgery who subsequently underwent surgery wherein general anesthesia with nitrous oxide was used. METHODS: The authors reviewed the charts of patients who had undergone vitreoretinal surgery where a long-acting gas tamponade had been used. These patients underwent additional surgery for a variety of reasons at five different institutions and had nitrous oxide used during general anesthesia. The authors reviewed the preoperative and postoperative findings for patients receiving nitrous oxide following vitreoretinal surgery with gas tamponade. RESULTS: The authors reviewed findings for five eyes of five patients. All eyes that underwent general anesthesia using nitrous oxide had significant preexisting intraocular gas bubbles ranging from 40% to 90%, and the surgical procedures lasted from 1 to 4 hours. These eyes were followed from 2 months to 9 years (median follow-up, 4 years). Four of five eyes had a final vision of 20/200 or worse and significant optic atrophy at the time of the last follow-up examination. Three eyes had no light perception. CONCLUSION: The use of nitrous oxide during general anesthesia in gas-filled eyes may have disastrous visual results caused by gas expansion and elevated intraocular pressure. Patients must be advised of the potentially catastrophic results of undergoing general anesthesia before their intraocular gas bubble has resorbed. The use of nitrous oxide for patients with intraocular gas should be avoided. It may be prudent for patients with intraocular gas to wear notification bracelets warning anesthesiologists about the presence of intraocular gas lest emergency surgery be needed by a patient unable to advise anesthesia personnel about the potential danger.