Assessing the accuracy of intracameral phenylephrine preparation in cataract surgery

Purpose: Unpreserved phenylephrine is often used as an off-licence intracameral surgical adjunct during cataract surgery to assist with pupil dilation and/or stabilise the iris in floppy iris syndrome. It can be delivered as a neat 0.2 ml bolus of either 2.5 or 10% strength, or in a range of ad-hoc dilutions. We wished to assess the accuracy of intracameral phenylephrine preparation in clinical practice. Methods: Phenylephrine 0.2 ml was analysed both neat (2.5 and 10%) and in diluted form (ratio of 1:1 and 1:3). Samples were analysed using the validated spectrophotometric method. Results: A total of 36 samples were analysed. The standard curve showed linearity for phenylephrine (R2 = 0.99). Wide variability was observed across all dilution groups. There was evidence of significant differences in the percentage deviations from intended results between dilutions (p < 0.001). Mean percentage deviation for 1:3 dilution was significantly greater than neat (p = 0.003) and 1:1 dilution (p = 0.001). There was no evidence of a significant difference between 1:1 and neat (p = 0.827). Conclusions: Current ad-hoc dilution methods used to prepare intracameral phenylephrine are inaccurate and highly variable. Small volume 1 ml syringes should not be used for mixing or dilution of drug. Commercial intracameral phenylephrine products would address dosage concerns and could improve surgical outcomes in cases of poor pupil dilation and/or floppy iris syndrome

Evidence of Compromised Blood-Spinal Cord Barrier in Early and Late Symptomatic SOD1 Mice Modeling ALS

Background: The blood-brain barrier (BBB), blood-spinal cord barrier (BSCB), and blood-cerebrospinal fluid barrier (BCSFB) control cerebral/spinal cord homeostasis by selective transport of molecules and cells from the systemic compartment. In the spinal cord and brain of both ALS patients and animal models, infiltration of T-cell lymphocytes, monocyte-derived macrophages and dendritic cells, and IgG deposits have been observed that may have a critical role in motor neuron damage. Additionally, increased levels of albumin and IgG have been found in the cerebrospinal fluid in ALS patients. These findings suggest altered barrier permeability in ALS. Recently, we showed disruption of the BBB and BSCB in areas of motor neuron degeneration in the brain and spinal cord in G93A SOD1 mice modeling ALS at both early and late stages of disease using electron microscopy. Examination of capillary ultrastructure revealed endothelial cell degeneration, which, along with astrocyte alteration, compromised the BBB and BSCB. However, the effect of these alterations upon barrier function in ALS is still unclear. The aim of this study was to determine the functional competence of the BSCB in G93A mice at different stages of disease. Methodology/Principal Findings: Evans Blue (EB) dye was intravenously injected into ALS mice at early or late stage disease. Vascular leakage and the condition of basement membranes, endothelial cells, and astrocytes were investigated in cervical and lumbar spinal cords using immunohistochemistry. Results showed EB leakage in spinal cord microvessels from all G93A mice, indicating dysfunction in endothelia and basement membranes and confirming our previous ultrastructural findings on BSCB disruption. Additionally, downregulation of Glut-1 and CD146 expressions in the endothelial cells of the BSCB were found which may relate to vascular leakage. Conclusions/Significance: Results suggest that the BSCB is compromised in areas of motor neuron degeneration in ALS mice at both early and late stages of the disease

A Randomized, Prospective, Observer-Masked Study Comparing Dropless Treatment Regimen Using Intracanalicular Dexamethasone Insert, Intracameral Ketorolac, and Intracameral Moxifloxacin versus Conventional Topical Therapy to Control Postoperative Pain and Inflammation in Cataract Surgery

Eric D Donnenfeld,1 John A Hovanesian,2 Aysha G Malik,1 Aidan Wong1 1Ophthalmic Consultants of Long Island, New York, NY, USA; 2Harvard Eye Associates, Laguna Hills, CA, USACorrespondence: Eric D Donnenfeld, Ophthalmic Consultants of Long Island (OCLI), 711 Stewart Avenue, Suite 160, Garden City, New York, NY, 11530, USA, Tel +1 516-500-4200, Fax +1 516-742-0017, Email [email protected]: To evaluate clinical efficacy and patient preference for a dropless treatment regimen compared to conventional topical therapy in patients undergoing cataract surgery.Patients and Methods: In this prospective, contralateral eye study, patients with bilateral cataract were randomized to receive either intracanalicular dexamethasone insert, intracameral phenylephrine 1%/ketorolac 0.3%, and intracameral moxifloxacin (50 μg) (study group) or topical moxifloxacin 0.5%, ketorolac 0.5%, and prednisolone acetate 1.0% QID (control group). The second eye underwent cataract surgery 2 weeks later and was treated with the opposite treatment. All patients were evaluated at Days 1, 7, 14, 28, and 3 months. The primary outcome measure was postoperative ocular pain. Secondary outcomes included summed ocular inflammation score (SOIS; the sum of the mean anterior chamber cells and anterior flare score), the patient preference for medication protocol between the two eyes, and patient out-of-pocket cost of medications. Safety outcome measures included CDVA, intraocular pressure, central retinal thickness (CRT), and the incidence of reported AEs.Results: The proportion of patients with no pain was similar in both groups at all postoperative visits (p> 0.05). No statistically significant difference in SOIS score was observed between the two groups at any visit. A strong majority of the patients (94.7%) preferred the study eye’s dropless regimen over the control eye’s conventional topical therapy regimen. No statistically significant difference in mean intraocular pressure (IOP) was observed at any postoperative visit, except at Week 1. The mean CDVA was also similar in both groups at all postoperative visits (p> 0.05). The postoperative mean CRT was comparable between the two groups.Conclusion: A dropless treatment regimen is as effective as topical eyedrop administration. A higher proportion of patients who underwent bilateral cataract surgery preferred the dropless treatment regimen over the patient-administered eye drop regimen.Keywords: dropless cataract surgery, intracanalicular dexamethasone insert, dropless vs topical eyedrop administration, sustained-release steroid delivery, drop-free treatment regime