Effects of intravitreal ropivacaine on retinal thickness and integrity in the guinea pig

Inflammatory signal transduction pathways induced by prilocaine toxicity in cultured ARPE-19 cells

Prilocaine (PRL) is a common local anesthetic. Despite the successful use of regional anesthesia for intraocular surgery, there are associated side effects that may affect the retina in case of accidental intravitreal injection. This study examined the signal transduction pathways activated by PRL toxicity and determined the protective role of nitric oxide synthase-2 (NOS2) inhibition in cultured human-derived retinal pigment epithelial cells (ARPE-19). Toxicity analysis was performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay to detect the toxic dose of PRL and protective effectiveness of asperglaucide (ASP), an NOS2 inhibitor. Nuclear factor kappa B p65 (NF-κB p65), phosphorylated NF-κB p65, phospho-protein kinase B (AKT), NOS2, nitrotyrosine, and cleaved caspase-3 protein levels were evaluated by immunofluorescence staining and/or western blot analysis. Interleukin-6 (IL-6) and nitrated protein levels were quantified using an immunoassay, whereas caspase-3 activity and nitrite/nitrate levels were measured using a fluorometric method. A significant increase in NF-κB p65, and phosphorylated NF-κB p65 and AKT levels due to PRL toxicity was observed. Similarly, IL-6, NOS2, nitrite/nitrate, and nitrotyrosine levels were significantly higher in PRL-treated cells than in control cells. Application of ASP to PRL-treated cells reduced NF-κB p65, and phosphorylated NF-κB p65 and AKT to basal levels. IL-6, NOS2, nitrite/nitrate, and nitrotyrosine levels also considerably decreased following ASP treatment in cells experiencing PRL-induced toxicity. Moreover, the caspase-3-dependent apoptotic pathway was not activated. Our results indicate that ASP could ameliorate PRL-induced activation of NF-κB p65 that led to inflammation in cultured ARPE-19 cells.

Inverted ILM Flap for a Needle Injury to the Macula after Peribulbar Anaesthesia: A Case Report and Literature Review

Globe perforation following peribulbar anesthetic injection is a rare but dreaded complication that often results in poor visual outcomes. This case report is on a female patient who sustained vitreous hemorrhage, retinal detachment, and macular breaks due to a peribulbar block administered in the setting of cataract extraction. The retina was repaired with pars plana vitrectomy, endolaser of the peripheral retinal break only, and an internal limiting membrane inverted flap for the macular breaks to avoid the endolaser on the macular area, achieving stable visual outcomes. The authors discussed various modes of local anesthesia for vitreoretinal surgery, risks for globe perforations, and how to approach retinal detachment secondary to needle perforations, which are complex cases at high risk for proliferative vitreoretinopathy. Early recognition and intervention in eyes with an inadvertent perforation can lead to a good outcome. Eyes with a longer axial length, superior, and multiple perforations are at higher risk of developing complications such as retinal detachment and vitreous hemorrhage. Complications such as retinal detachment, macular injury, and vascular occlusion are risk factors for poor prognosis.

Comparative clinical trial of intracameral ropivacaine vs. lignocaine in subjects undergoing phacoemulsification under augmented topical anesthesia

Purpose:

To compare intracameral Ropivacaine to Lignocaine during phacoemulsification under augmented topical anesthesia, in terms of efficacy and safety.

Methods:

This prospective, randomized, double-masked clinical trial included subjects planned for phacoemulsification with posterior chamber intraocular lens implantation for visually significant uncomplicated senile cataract, under augmented topical anesthesia. Cases were randomized into two groups, Group A (Ropivacaine 0.1%) or Group B (Lignocaine 1.0%). The pain experienced by the patients during the surgery, mydriasis, post-op inflammation and endothelial cell change at six weeks after the procedure was evaluated. Surgeon's feedback was recorded to evaluate the cooperation of the patient during surgery.

Results:

A total of 210 subjects were screened and 184 were randomized to have 92 subjects in each group. There was no statistically significant difference seen on comparing Group A and B with respect to Age (P = 0.05), painful surgical steps (P = 0.85), visual analog scale scores (P = 0.65), surgeon's score (P = 0.11), postoperative inflammation (P = 0.90) and average ultrasound time during phacoemulsification (P = 0.10). Subjects in Group A fared better when compared to Group B with respect to endothelial cell loss (P = 0.0008), and augmentation in mydriasis (P < 0.001).

Conclusion:

Intracameral Ropivacaine and Lignocaine, both are equally effective in providing analgesia during phacoemulsification. However, intracameral Ropivacaine is superior to Lignocaine with regards to corneal endothelial cell safety, and augmenting mydriasis.

Inadvertent globe penetration during retrobulbar anesthesia: A case report

BACKGROUND

To report the possible reasons for needle perforation and complications related to perforation, as well as the clinical management of subretinal hemorrhage (SRH) during retrobulbar injection.

CASE SUMMARY

A 65-year-old female was scheduled to undergo pars plana vitrectomy (PPV) in her left eye for rhegmatogenous retinal detachment (RRD). During retrobulbar anesthesia, needle perforation of the globe occurred. Massive SRH in the inferotemporal quadrant together with vitreous hemorrhage were observed. The patient underwent PPV combined with retinotomy for removal of the massive SRH. After earlier surgical intervention, successful reattachment of the retina was achieved.

CONCLUSION

Inadvertent globe penetration during retrobulbar anesthesia is associated with a poor prognosis and may result in blindness. Timely detection and earlier intervention may be beneficial.

Prospective insulin-based ophthalmic delivery systems for the treatment of dry eye syndrome and corneal injuries

The presence of insulin (INS) receptors on the ocular surface (OS) and lacrimal gland (LG), and the high prevalence of dry eye syndrome (DES) and corneal lesions in diabetic patients suggest that INS is relevant for OS homeostasis and wound healing. The study aims at developing delivery systems for the topical administration of INS to the OS in order to improve INS local bioavailability and evaluate the influence of the delivery systems on DES in diabetic rats (DM) (n = 05/group). Chitosan microparticles (MP), chitosan/poloxamer gel (GEL) and MP-loaded GEL (GELMP), with or without INS were developed. Formulations were instilled into the eyes of diabetic rats (DM) for 15 days and the tear fluid volume, corneal cells morphology and cornea thickness were assessed and compared with an aqueous dispersion of INS (DISP-INS). All delivery systems had pH of about 6, osmolality suitable for topical application and positive zeta potential. The MPs with or without INS had sizes close to 4 μm, spherical morphology and INS encapsulation efficiency of 77 ± 6%. DISP-INS and GELMP-INS formulations produced tear secretion amounts significantly higher than those receiving formulations containing no INS and similar to healthy animals. Cornea surface impression cytology showed that treatment with INS-delivery systems and not DISP-INS almost normalized cells morphology. Treatment with GELMP-INS increased INS by 2.5 in the LG and eyeball as compared to the groups treated with GEL-INS and MP-INS, while treatment with DISP-INS left no traces of drug in the eye after treatment termination. GEL and GELMP containing INS were also able to normalize the thickness of the corneal epithelia. In conclusion, GELMP-INS normalized tear fluid volume, corneal thickness, protected corneal cells morphology and increased ocular bioavailability of INS, making it a promising treatment strategy for DES and corneal lesions.