Comparison between ropivacaine and bupivacaine in deep topical fornix nerve block anesthesia in patients undergoing cataract surgery by phacoemulsification

Recent trends in anesthetic agents and techniques for ophthalmic anesthesia

Effective and safe ophthalmic anesthesia is essential for the delivery of ophthalmic perioperative care both for children and adults. Recent years have seen a major change in form of smaller incisions for most ophthalmic surgical techniques, thus making them less invasive. Additionally, most ophthalmic surgeries are now day-care surgeries at ambulatory surgical centers. The parallel advancements in the field of anesthesiology have boosted the standard of perioperative care. The purpose of this narrative review was to evaluate current trends in anesthetic agents and techniques for ophthalmic anesthesia primarily centered around deep sedation and general anesthesia as per the concerns of practicing anesthesiologists while briefly acquainting with local anesthesia advances.

Development and Optimization of Chitosan-Hydroxypropyl Methylcellulose In Situ Gelling Systems for Ophthalmic Delivery of Bupivacaine Hydrochloride

The aim of this study was the development and optimization of chitosan and hydroxypropyl methylcellulose (HPMC) in situ gelling systems, loaded with bupivacaine hydrochloride for topical ocular administration. This study is based on the properties of two polymers: chitosan, which has mucoadhesive action and is a pH-sensitive polymer, but also the cellulose derivative hydroxypropyl methylcellulose, a thermosensitive polymer which has mucoadhesive properties and increases the viscosity of systems. The analysis and optimization of in situ gelling systems were performed based on an experimental design and response surface methodology. The following formulation parameters were considered: X1 = chitosan concentration (0.5%, 1%), X2 = HPMC E 5 LV concentration (2%, 5%) and X3 = Chitosan/HPMC E 5 LV ratio (1/1, 2/1). In addition, the parameters to be optimized were represented by the contact angle (CA (°)), viscosity and cumulative percentage of bupivacaine hydrochloride released in vitro. The results indicate that the designed in situ gelling systems are suitable for bupivacaine prolonged ophthalmic release and overcome the principal disadvantages of the liquid’s ocular formulations. An immediate therapeutic effect corresponding to ocular anesthetic installation was assured in the first stage: burst bupivacaine release. In the second phase, the gradual drug release was assured for over 6 h. This drug release profile, together with the corresponding rheological profile and a collection of superficial properties for good ocular adhesion balanced with an adequate hydrophilic character, assured the desired quality of the attributes for the proposed systems. The system, based on chitosan 1%, HPMC E 5 LV 5% and a 1/1 polymer ratio, could be a solution for the proposed formulation of in situ gelling colloidal systems, since the viscosity of the system was within the range of the optimal viscosity of the eye, and the amount of bupivacaine hydrochloride released after 6 h was the highest at 69.55%.

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.

A prospective observational cohort study to evaluate patients' experience during sequential cataract surgery under monitored anesthesia care and topical anesthesia

Cataract surgery is the most common ambulatory surgery at our outpatient surgery center. Several studies have shown that patients with bilateral cataracts may experience different levels of anxiety, pain, and awareness during the first and second cataract extraction.A prospective observational cohort study was conducted at The Ohio State University Wexner Medical Center Eye and Ear Institute in order to compare anxiety, general comfort, awareness, and pain levels in patients undergoing sequential cataract surgeries. Likert and numerical rating scale were used to assess the outcomes. Patients receiving monitored anesthesia care and topical anesthesia were included.A total of 198 patients were enrolled in this study, 116 patients (59%) were female and 157 patients (78%) were Caucasians with a median age of 67 years among participants. Patients with rating "no anxiety" or feeling "somewhat anxious" were significantly higher during surgery 2 (P =< .001). Most of the patients felt "extremely comfortable" during surgery 1 when compared to surgery 2 (54% vs 42.9%; P = .08). No significant differences were found between surgeries regarding intraoperative awareness (P = .16). Overall, patients experienced mild pain during both procedures (92.4% in surgery 1 compared to 90.4% in surgery 2; P = .55). During the postoperative visit, 54% of the patients associated surgery 2 with less anxiety levels, 53% with no differences in general comfort, 60% felt more aware, and 59% had no differences in pain levels.Previous exposure to surgery could have been associated with a significant reduction in anxiety levels reported during surgery 2. Non-pharmacological strategies aiming to reduce perioperative anxiety may be considered an alternative or additional approach to premedication in patients undergoing consecutive cataract surgeries.

Effects of topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride on corneal sensitivity in rats

The aim of the present study was to determine and compare the degree and duration of corneal anesthesia following topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride treatment in healthy rats. A randomized, blinded, crossover study was conducted on 20 healthy adult Wistar rats, following complete physical and ophthalmological examination. Baseline corneal touch threshold (CTT) was determined in the central corneal area of both eyes with a Cochet–Bonnet aesthesiometer, in mm filament length. Oxybuprocaine was randomly applied to one eye and 0.9% sterile sodium chloride solution was instilled into the contralateral eye. Subsequent CTT measurements were performed in both eyes 5 minutes after topical application and at 5-minute intervals thereafter for 75-minutes in the anesthetized eye. Following a 2-week washout period, this protocol was repeated with ropivacaine. Quantitative data were summarized as mean ± standard deviation, median and inter-quartile range (Q1–Q3). Repeated measures data were analyzed over time and between treatments using Friedman test and Wilcoxon signed-rank test with Bonferroni adjustment (p < 0.05). Baseline CTT values were 60 mm in all eyes. With oxybuprocaine, CTT values decreased significantly for 65 minutes (0–55 mm; p = 0.002) when compared with baseline; the maximal anesthetic effect (no blink response at 5 mm filament length) was maintained for up to 15 minutes (p < 0.0001). With ropivacaine, CTT values were significantly lower than baseline for 30 minutes (0–55 mm; p = 0.002), with a maximal anesthetic effect recorded at 5 minutes in 18 eyes (p < 0.0001). Oxybuprocaine induced a significantly lower CTT than ropivacaine (p = 0.002) from 10 to 65 minutes following topical application. Both anesthetic agents induced significant corneal anesthesia; however, oxybuprocaine provided a greater and longer anesthetic effect, making it more suitable for potentially painful ophthalmologic procedures.