Chloroprocaine 3% Gel as a Novel Ocular Topical Anesthetic: Results from a Multicenter, Randomized Clinical Trial in Patients Undergoing Cataract Surgery.

Purpose: To compare the efficacy and safety of a novel ophthalmic anesthetic, chloroprocaine 3% gel to tetracaine 0.5% eye drops in patients undergoing cataract surgery with phacoemulsification. Methods: This was a prospective, randomized, multicenter, active-controlled, masked-observer, parallel group competitive equivalence study. The study comprised 338 patients having routine cataract extraction by clear corneal phacoemulsification, randomized to receive 3 drops of chloroprocaine gel (n = 166) or tetracaine eye drops (n = 172) before surgery. The primary objective of the study was to assess the equivalence of chloroprocaine gel to tetracaine eye drops as proportion of patients with successful ocular surface anesthesia, without any supplementation just before intraocular lens implantation. Safety measurements were pain, irritation, burning, stinging, photophobia, and foreign body sensation, graded by the patient and objective ocular signs. Results: Equivalence was demonstrated, with a somewhat higher success rate of chloroprocaine gel: 152/166 (92.0%) chloroprocaine versus 153/172 (90.5%) tetracaine patients achieved ocular surface anesthesia with no supplementation. Difference in proportions was 1.5% confidence interval [95% CI: (-3.6 to 6.6)] and 90% CI fell within (-10 to 10). Mean onset of anesthesia was 1.35 ± 0.87 min for chloroprocaine and 1.57 ± 1.85 for tetracaine (P = 0.083). Mean duration of anesthesia was 21.57 ± 12.26 min for chloroprocaine and 22.04 ± 12.58 for tetracaine (P = 0.574). No treatment emergent adverse events related to chloroprocaine were reported and no relevant findings related to local tolerance or vital signs were observed in both arms. Conclusions: Results obtained from the present cataract study demonstrated that chloroprocaine 3% ophthalmic gel is safe and effective, representing a valid alternative in ocular topical anesthesia. Clinical Trial Registration number: NCT04685538.

Evaluation of corneal anaesthesia after the application of topical 0.5% bupivacaine, 2% lidocaine and 0.4% oxybuprocaine in normal horses.

OBJECTIVE: To compare the corneal anaesthetic effect of 0.5% bupivacaine, 2% lidocaine and 0.4% oxybuprocaine on normal equine eyes. STUDY DESIGN: Prospective, blinded crossover study. ANIMALS: A group of 10 clinically healthy horses. METHODS: Corneal sensitivity was determined in each eye by measuring corneal touch threshold (CTT). The study had three phases. Each subject was randomly given one of the three treatments followed by a 72 hour washout period. Every horse received all treatments. Baseline CTT was recorded prior to anaesthetic instillation (T0) then CTT was measured 5 and 10 minutes after (T1 and T2, respectively), then 20 to 90 minutes (T3 to T10) at 10 minute intervals. CTT data were compared among treatments at each time point using the Friedman test p < 0.05. RESULTS: Median (range) baseline CTT was 51.3 (25.0-60.0) mm for bupivacaine, 50.0 (40.0-55.0) mm for oxybuprocaine and 55.0 (30.0-60.0) mm for lidocaine. All treatments caused a significant decrease in CTT at T1. The lowest CTT was observed at T3 with bupivacaine and oxybuprocaine treatments. Median CTTs at this time point were 18.7 (5.0-25.0) mm and 28.7 (25.0-40.0) mm, respectively. The lowest CTT with lidocaine treatment was 28.7 (20.0-50.0) mm at T6 (50 minutes). At T3, CTT was significantly lower with the bupivacaine treatment compared with oxybuprocaine and lidocaine treatments (p < 0.0074). There was no significant difference in CTT values between T1 and T6 for bupivacaine, between T1 and T7 for lidocaine, and between T1 and T8 for oxybuprocaine. Duration of the maximum effect was 45 minutes for the bupivacaine, 55 minutes for the lidocaine and 65 minutes for the oxybuprocaine treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of a 0.5% injectable solution of bupivacaine or a 2% lidocaine had similar anaesthetic effect to the commonly used oxybuprocaine. Therefore, they might be used as alternatives for corneal anaesthesia.

Pentadecapeptide BPC 157 shortens duration of tetracaine- and oxybuprocaine-induced corneal anesthesia in rats.

We focused on the relationship of 0.5% tetracaine- and 0.4% oxybuprocaine-induced corneal anesthesia in rats, and pentadecapeptide BPC 157 (0.4 µg/eye), along with nitric oxide synthase (NOS) inhibitor N(gamma)-nitro-L-arginine methyl ester (L-NAME) (0.1 mg/eye) and/or NOS substrate L-arginine (2 mg/eye), applied in the form of eye drops. We assessed corneal sensitivity recovery (Cochet-Bonnet esthesiometer), corneal lesion elimination (staining with 10% fluorescein) and decrease in tear volume (Schirmer test). BPC 157 administration had a full counteracting effect. Recovery also occurred in the presence of NOS blockade and NOS substrate application. L-arginine eventually shortened duration of corneal insensitivity and exerted corneal lesion counteraction (and counteraction of tetracaine-induced decrease of tear volume) only in earlier but not in later period. L-NAME application led to longer duration of corneal insensitivity, increase in corneal lesions and decrease in tear volume. When L-NAME and L-arginine were applied together, they antagonized each other's effect. These distinctions may indicate particular NOS involvement (corneal insensitivity vs. corneal lesion along with tear production), distinctively affected by the administration of NO agents. However, additional BPC 157 co-administration would re-establish counteraction over topical ophthalmic anesthetic-induced effect, be it in its early or late course. We suggest BPC 157 as an antidote to topical ophthalmic anesthetics.

Serotonin enhances oxybuprocaine- and proxymetacaine-induced cutaneous analgesia in rats.

The aim of the study was to investigate the analgesic effects of adding serotonin to oxybuprocaine or proxymetacaine preparations. We employed a rat model of the cutaneous trunci muscle reflex (CTMR) to conduct the dose-response curves and duration of drugs (oxybuprocaine, proxymetacaine, or serotonin) as an infiltrative anesthetic. The use of isobolographic methods to analyze the drug-drug interactions. We showed that oxybuprocaine and proxymetacaine, as well as serotonin produced dose-dependent skin antinociception. On the basis of 50% effective dose (ED50), the rank order of drug potency was serotonin [7.22 (6.45-8.09) µmol/kg] < oxybuprocaine [1.03 (0.93-1.15) µmol/kg] < proxymetacaine [0.59 (0.53-0.66) µmol/kg] (P < 0.01 for each comparison). The sensory block duration of serotonin was longer (P < 0.01) than that of oxybuprocaine or proxymetacaine at the equipotent doses (ED25, ED50, and ED75). The mixture of serotonin with oxybuprocaine or proxymetacaine produced a better analgesic effect than the drug itself. We have concluded that oxybuprocaine, proxymetacaine, or serotonin displays dose-related cutaneous analgesia. Oxybuprocaine or proxymetacaine is more potent and has a shorter duration of cutaneous analgesia than serotonin. Serotonin produces a synergistic antinociceptive interaction with oxybuprocaine or proxymetacaine.

Using chloroprocaine for spinal anaesthesia in outpatient knee-arthroscopy results in earlier discharge and improved operating room efficiency compared to mepivacaine and prilocaine.

PURPOSE: Knee arthroscopies are regularly carried out in an outpatient setting. The purpose of this retrospective analysis was to investigate the impact of different local anaesthetics for spinal anaesthesia on operating room efficiency (perioperative process times) and postoperative recovery. This study aims to determine the optimal LA for SPA in patients undergoing knee arthroscopy at a day-surgery centre. METHODS: Anaesthesia records of all patients undergoing knee arthroscopy under spinal anaesthesia from 2010 until 2017 were analysed. Patients were categorised as having received spinal anaesthesia with prilocaine, mepivacaine or chloroprocaine. RESULTS: Three-hundred and nine patients were included. Postoperative recovery was significantly faster for chloroprocaine 1% compared with both other local anaesthetics regarding all stages of recovery until discharge. Perioperative processes and surgery time were significantly shorter when chloroprocaine was used. Early postoperative pain occurred more frequently and earlier after spinal anaesthesia with chloroprocaine. Nevertheless, pain intensity did not differ between groups. CONCLUSION: Spinal anaesthesia provides reliable blocks for outpatient knee arthroscopy. Considerations on the choice of local anaesthetic for spinal anaesthesia must include not only the recovery profile, but also the impact on operating room efficiency. Due to a superior recovery profile, low incidences of adverse side effects and raised operating room efficiency, chloroprocaine is the recommendable local anaesthetic for spinal anaesthesia in patients undergoing knee arthroscopy in an ambulatory setting. Since the frequency of SPA in patients undergoing outpatient knee arthroscopy is rising yearly, the results of this study are of high clinical relevance. The use of chloroprocaine leads to improved recovery, optimized perioperative processes and consecutively to a raised OR efficiency. LEVEL OF EVIDENCE: III.

New local anesthetics.

Local anesthetics are used for performing various regional anesthesia techniques to provide intraoperative anesthesia and analgesia, as well as for the treatment of acute and chronic pain. Older medications such as lidocaine and bupivacaine as well as newer ones such as mepivacaine and ropivacaine are being used successfully for decades. Routes of administration include neuraxial, perineural, intravenous, various infiltrative approaches, topical, and transdermal. There are new innovations with the use of older local anesthetics in a novel manner, in addition to the development and use of new formulations. This chapter seeks to summarize the pharmacokinetics of local anesthetics and address the role of newer local anesthetics, as well as clinical implications, safety profiles, and the future of local anesthetic research. Finally, some clinical pearls are highlighted.

Adding Dopamine to Proxymetacaine or Oxybuprocaine Solutions Potentiates and Prolongs the Cutaneous Antinociception in Rats.

BACKGROUND: We evaluated the interaction of dopamine-proxymetacaine and dopamine- oxybuprocaine antinociception using isobolograms. METHODS: This experiment uses subcutaneous drug (proxymetacaine, oxybuprocaine, and dopamine) injections under the skin of the rat's back, thus simulating infiltration blocks. The dose-related antinociceptive curves of proxymetacaine and oxybuprocaine alone and in combination with dopamine were constructed, and then the antinociceptive interactions between the local anesthetic and dopamine were analyzed using isobolograms. RESULTS: Subcutaneous proxymetacaine, oxybuprocaine, and dopamine produced a sensory block to local skin pinpricks in a dose-dependent fashion. The rank order of potency was proxymetacaine (0.57 [0.52-0.63] µmol/kg) > oxybuprocaine (1.05 [0.96-1.15] µmol/kg) > dopamine (165 [154-177] µmol/kg; P < .01 for each comparison) based on the 50% effective dose values. On the equianesthetic basis (25% effective dose, 50% effective dose, and 75% effective dose), the nociceptive block duration of proxymetacaine or oxybuprocaine was shorter than that of dopamine (P < .01). Oxybuprocaine or proxymetacaine coinjected with dopamine elicited a synergistic antinociceptive effect and extended the duration of action. CONCLUSIONS: Oxybuprocaine and proxymetacaine had a higher potency and provoked a shorter duration of sensory block compared with dopamine. The use of dopamine increased the quality and duration of skin antinociception caused by oxybuprocaine and proxymetacaine.

Degree of corneal anesthesia after topical application of 0.4% oxybuprocaine ophthalmic solution in normal equids.

Oxybuprocaine hydrochloride ophthalmic solution has been widely used off-label in horses and donkeys, despite lack of data demonstrating efficacy and safety in these species. The objective of this study was to assess anesthetic efficacy of 0.4% oxybuprocaine hydrochloride ophthalmic solution in horses (n = 5) and donkeys (n = 24) and compare the effects with 0.5% proparacaine hydrochloride ophthalmic solution. The baseline corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer. Donkeys (n = 12) and horses (n = 5) in group A received sterile ophthalmic solutions 0.4% oxybuprocaine with fluorescein (also termed benoxinate with fluorescein, abbreviated as ben + flu) instilled in one eye and 0.9% sterile sodium chloride solution (NaCl) with fluorescein (Na + flu) in the contralateral eye. Donkeys (n = 12) and horses (n = 5) in group B received sterile ophthalmic solutions (ben + flu) in one eye and 0.5% proparacaine with fluorescein (prop + flu) in the contralateral eye. The CTT was measured at 1 and 5 min post-application and at 5-minute intervals until 75 min after treatment. The CTT changes over time differed significantly between oxybuprocaine-treated and control eyes (P < 0.001). The CTT continued to decrease throughout the duration of the study when compared with baseline values. No statistically significant difference in onset, depth, or duration of corneal anesthesia was found between oxybuprocaine and proparacaine treated eyes during the time of the study. Interestingly, horses were shown to have a significantly more sensitive cornea than donkeys (P = 0.002). Oxybuprocaine and proparacaine reduced corneal sensitivity in donkeys and horses. No local irritation was observed with 0.4% oxybuprocaine.

La solution ophtalmique d'hydrochlorure d'oxybuprocaïne a été utilisée extensivement en dérogation chez les chevaux et les ânes, malgré le manque de données démontrant son efficacité et son innocuité chez ces espèces. L'objectif de la présente étude était d'évaluer l'efficacité anesthétique d'une solution ophtalmique d'hydrochlorure d'oxybuprocaïne 0,4 % chez des chevaux (n = 5) et des ânes (n = 24) et comparer les effets avec une solution ophtalmique d'hydochlorure de proparacaïne 0,5 %. La valeur de base du seuil de contact cornéen (SCT) a été mesurée à l'aide d'un esthésiomètre Cochet-Bonnet. Les ânes (n = 12) et chevaux (n = 5) du groupe A ont reçu une solution ophtalmique stérile d'oxybuprocaïne 0,4 % avec de la fluorescéine (également appelée benoxinate avec fluorescéine, abrévié ben + flu) dans un oeil et une solution stérile de chlorure de sodium 0,9 % (NaCl) avec de la fluorescéine (Na + flu) dans l'oeil contra-latéral. Les ânes (n = 12) et chevaux (n = 5) du groupe B ont reçu les solutions ophtalmiques stériles de (ben + flu) dans un oeil et de la propacaïne 0,5 % avec de la fluorescéine (prop + flu) dans l'oeil contra-latéral. Le SCT a été mesuré à 1 et 5 min post-application et à des intervalles de 5 min jusqu'à 75 min après le traitement. Les changements dans le temps du SCT différaient de manière significative entre les yeux traités à l'oxybuprocaïne et les témoins (P < 0,001). Le SCT continua de diminuer tout au long de la durée de l'étude lorsque comparé aux valeurs de base. Aucune différence significative dans le début, la profondeur, ou la durée de l'anesthésie cornéenne ne fut trouvée entre les yeux traités à l'oxybuprocaïne et la proparacaïne durant la durée de l'étude. De manière intéressante, les chevaux avaient une cornée significativement plus sensible que les ânes (P = 0,002). L'oxybuprocaïne et la proparacaïne ont réduit la sensibilité cornéenne chez les ânes et les chevaux. Aucune irritation locale ne fut observée avec l'oxybuprocaïne 0,4 %.(Traduit par Docteur Serge Messier).

Can the choice of the local anesthetic have an impact on ambulatory surgery perioperative costs? Chloroprocaine for popliteal block in outpatient foot surgery.

STUDY OBJECTIVE: Short-acting regional anesthetics have already been successfully used for peripheral nerve blocks in an ambulatory surgery setting. However, the impact on direct and indirect perioperative costs comparing 2 different short-acting local anesthetics has not been performed yet. DESIGN: Observational, prospective, case-control, cost-minimization study. SETTING: Operating room, regional hospital PATIENTS: One hundred adult American Society of Anesthesiologists status I-III patients scheduled for popliteal block after minor ambulatory foot surgery. INTERVENTIONS: Application of 30 mL chloroprocaine 3% or of 30 mL mepivacaine 1.5% for anesthesia. MEASUREMENTS: Cost-minimization evaluation. Direct and indirect perioperative costs were calculated. Block success, onset time and block duration, patient satisfaction, and unplanned outpatient visits or readmissions after discharge were also assessed. MAIN RESULTS: Onset time (sensory: 4.3 ± 2.4 vs 11.5 ± 3.2 minutes; motor: 7.1 ± 3.7 vs 18.4 ± 4.5 minutes) and block duration (sensory: 105 ± 26 vs 317 ± 46 minutes; motor: 91 ± 25 vs 216 ± 31 minutes) were significantly shorter (P < .001) when chloroprocaine 3% was used. This translated to P < .001, basically due to a faster discharge home 55 ± 1 vs 175 ± 2 minutes; P < .001) in favor of chloroprocaine 3%, without negatively affecting either block efficacy or patients satisfaction. There were no unplanned outpatient visits or readmissions and no complications in the follow-up at 6 weeks. CONCLUSIONS: We conclude that the more expensive chloroprocaine 3% for ambulatory foot surgery can reduce total perioperative costs and reduce length of stay in outpatient patients. Moreover, the saved time and personal resources could be used for additional cases, further increasing the revenues of an ambulatory surgical center.

Degree of corneal anaesthesia after topical application of 0.4% oxybuprocaine hydrochloride and 0.5% proparacaine hydrochloride ophthalmic solution in clinically normal cattle.

OBJECTIVES: The use of corneal anaesthesia is necessary for a range of clinical purposes. Therefore, we assessed and compared the efficacy of corneal anaesthesia after application of 0.4% oxybuprocaine hydrochloride and 0.5% proparacaine hydrochloride ophthalmic solution in clinically normal cattle. METHODS: The 24 clinically normal cows were allocated into two groups. Cows in group 1 (n = 12) received 0.2 mL of 0.4% oxybuprocaine hydrochloride with fluorescein ophthalmic solution in one eye and 0.2 mL of sterile saline (0.9% NaCl) with fluorescein in the contralateral eye (control). Group 2 (n = 12) received 0.2 mL of 0.4% oxybuprocaine hydrochloride with fluorescein ophthalmic solution in one eye and 0.2 mL of 0.5% proparacaine hydrochloride with fluorescein in the contralateral eye (control). In each group, corneal touch threshold was determined by Cochet-Bonnet aesthesiometer for both eyes immediately prior to topical administration of solutions, at 1 min and 5 min after administration of topical solutions and every 5 min thereafter for a total of 75 min. RESULTS: Significant corneal anaesthesia was noted immediately following topical application of both oxybuprocaine and proparacaine as compared with controls, with maximal corneal anaesthesia noted 1 min after administration. Both oxybuprocaine and proparacaine produced significant corneal anaesthesia for the duration of the 75-min study. Neither oxybuprocaine hydrochloride nor proparacaine hydrochloride treatment resulted in visible adverse effects. CONCLUSION: There are limited data available demonstrating the efficacy and duration of corneal anaesthetic agents in cattle. Both oxybuprocaine hydrochloride and proparacaine hydrochloride should be considered practical options for providing corneal anaesthesia in cattle in a clinical setting.

Single-stage surgery for symptomatic small-angle strabismus under topical anaesthesia.

OBJECTIVE: To report outcomes of single-stage surgery under topical anaesthesia for the treatment of small-angle strabismus. DESIGN: Case series. PARTICIPANTS: Thirteen patients, 7 males and 6 females, with a median age of 32 years (range, 20-59 years) were included. METHODS: Patients with symptomatic small-angle strabismus with stable deviations of no more than 20 prism diopters (PD) in horizontal and 10 PD in vertical were consecutively recruited from the Eye and ENT Hospital of Fudan University between January 2010 and April 2012. Single-stage surgery was performed under topical anaesthesia. Outcome measures were PD, Amblyopia and Strabismus Questionnaire (ASQE) scores, and subjective reduction of symptoms. RESULTS: The median duration of symptoms was 40 months (range, 6-96 months). Nine patients had horizontal deviations, 3 had vertical deviations, and 1 had an exodeviation combined with a vertical deviation. All surgeries were completed without complications, and no patients experienced significant discomfort. All patients reported elimination of symptoms on postoperative day 1. Two patients required a second procedure at 1 week because of a return of symptoms. At 6-month follow-up, no patient reported recurrence of symptoms. The overall ASQE score improved from 70 preoperatively to 96 postoperatively (p = 0.001). CONCLUSIONS: These results suggest single-stage surgery under topical anaesthesia is an effective treatment for small-angle strabismus. A large, randomized, prospective study to confirm these findings is warranted.

The effect of different doses of chloroprocaine on saddle anesthesia in perianal surgery.

PURPOSE: To investigate a saddle anesthesia with different doses of chloroprocaine in perianal surgery. METHODS: Total 60 Patients aged 18-75 years (Anesthesiologists grade I or II) scheduled to receive perianal surgery. Patients using saddle anesthesia were randomized to group A, group B and group C with the same concentration (0.5%) chloroprocaine with different doses 1.0 mL, 0.8 mL and 0.6 mL, respectively. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and the sensory and motor block were recorded to evaluate the anesthesia effect of chloroprocaine in each group. RESULTS: The duration of sensory block of group C is shorter than those of group A and B. The maximum degree of motor block is observed (group C: 0 level, group A: III level; and group B: I level) after 15 minutes. Besides, there was a better anesthetic effect in group B than group A and group C, such as walking after saddle anesthesia. However, there is also no significant difference of blood pressure decreasing in these three groups. CONCLUSION: It's worth to employ a saddle anesthesia with appropriate doses of chloroprocaine in clinical perianal surgery.

Degree and duration of corneal anesthesia after topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution in ophthalmically normal dogs.

OBJECTIVE: To assess the anesthetic efficacy and local tolerance of topically applied 0.4% oxybuprocaine ophthalmic solution to in dogs and compare its effects with those of 1% tetracaine solution. ANIMALS: 34 ophthalmically normal Beagles. PROCEDURES: Dogs were assigned to 2 groups, and baseline corneal touch threshold (CTT) was measured bilaterally with a Cochet-Bonnet aesthesiometer. Dogs of group 1 (n = 22) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and saline (0.9% NaCl) solution (control treatment) in the contralateral eye. Dogs of group 2 (n = 12) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and 1% tetracaine ophthalmic solution in the contralateral eye. The CTT of each eye was measured 1 and 5 minutes after topical application and then at 5-minute intervals until 75 minutes after topical application. RESULTS: CTT changes over time differed significantly between oxybuprocaine-treated and control eyes. After instillation of oxybuprocaine, maximal corneal anesthesia (CTT = 0) was achieved within 1 minute, and CTT was significantly decreased from 1 to 45 minutes, compared with the baseline value. No significant difference in onset, depth, and duration of corneal anesthesia was found between oxybuprocaine-treated and tetracaine-treated eyes. Conjunctival hyperemia and chemosis were detected more frequently in tetracaine-treated eyes than in oxybuprocaine-treated eyes. CONCLUSIONS AND CLINICAL RELEVANCE: Topical application of oxybuprocaine and tetracaine similarly reduced corneal sensitivity in dogs, but oxybuprocaine was less irritating to the conjunctiva than was tetracaine.

Selective spinal anesthesia for outpatient transurethral prostatectomy (TURP): randomized controlled comparison of chloroprocaine with lidocaine.

BACKGROUND: This is a study comparing two short-acting local anesthetics lidocaine and 2-chloroprocaine in combination with fentanyl, to provide selective spinal anesthesia for outpatient transurethral resection of the prostate (TURP). METHODS: In this prospective, randomized double-blind study, selective spinal anesthesia was performed in 40 American Society of Anesthesiologists I-III outpatients undergoing TURP using either 40 mg of chloroprocaine mixed with 12.5 µg of fentanyl (n = 20) or 35 mg of lidocaine mixed with 12.5 µg of fentanyl (n = 20). The primary outcome was duration of spinal block. Secondary outcomes were time to reach T10 (onset), time to maximal level, duration above T10 and lidocaine 3, maximal level of block, and adverse effects. RESULTS: The median (minimum, maximum) onset time was 4 (1, 16) and 3 (2, 10) min for chloroprocaine and lidocaine, respectively. Time to maximal level was 20 (17, 29) and 22 (16, 26) min for chloroprocaine and lidocaine, respectively. Mean maximal level was T7-T8 for both agents. Duration of block above T10 was 54 (28, 88) and 63 (31, 87) min for chloroprocaine and lidocaine, respectively. Duration of block above lidocaine 3 was 93 (56, 218) and 98 (58, 151) min for chloroprocaine and lidocaine, respectively. There was no statistical difference between the two groups with respect to these clinical end points. Four patients in the lidocaine group developed transient neurological symptoms. One patient in the chloroprocaine group developed a cauda equina-like syndrome but recovered fully after several weeks. CONCLUSIONS: Selective spinal anesthesia with chloroprocaine and lidocaine for TURP yielded comparable results for clinical characteristics. Further research on transient neurological symptom and cauda equina risk with chloroprocaine is warranted.

Surgery for esotropia under topical anesthesia.

PURPOSE: To compare a surgically adjusted dose of strabismus surgery using topical anesthesia in cooperative patients with dosage guidelines adapted to the surgeon's personal technique using sub-Tenon's anesthesia. DESIGN: Randomized, controlled, single-site clinical trial. PARTICIPANTS: Sixty patients with nonparalytic, nonrestrictive esotropia who were cooperative for surgery under topical anesthesia. METHODS: Twenty-eight patients were assigned to topical anesthesia, and 32 patients were assigned to sub-Tenon's anesthesia. Visual acuity, refraction, and deviation angle were determined in all patients preoperatively and postoperatively, and stereoacuity was measured postoperatively. Deviation angle was measured by simultaneous and alternate prism and cover test, and stereoacuity was measured using Randot circles (Stereo Optical Co., Chicago, IL). The amount of surgery under topical anesthesia was adjusted intraoperatively. MAIN OUTCOME MEASURES: The amount of surgery used in the 2 treatment groups (measured in millimeters and millimeter/degree of deviation angle) and 6-month motor and stereoacuity outcomes. RESULTS: Patients in the topical group required 3.2 mm less surgery on average than those in the sub-Tenon's group (5.9 and 9.1 mm, respectively; 0.4 and 0.6 mm of recession/degree, respectively) (P<0.01). Motor success (84% and 75%, respectively, P=0.38) and stereoacuity (339.6 and 323.9 arc seconds, respectively, P=0.87) at 6 months were similar in the 2 groups. CONCLUSIONS: Topical anesthesia requires a smaller amount of surgery and number of operated muscles to correct esotropia compared with classic surgery guidelines adapted to the surgeon's personal technique.

Transepithelial corneal collagen cross-linking in keratoconus.

PURPOSE: To evaluate the clinical effects of transepithelial corneal cross-linking (CXL) on keratoconic eyes pre-treated with substances enhancing epithelial permeability. METHODS: Prospective, consecutive, single-masked, paired-eye study on 51 patients. The eye with more severe keratoconus was treated; the fellow eye served as the control. Gentamicin, benzalkonium chloride, and ethylenediaminetetraacetic acid were instilled for 3 hours, then oxybuprocaine for 30 minutes. Riboflavin 0.1% in 20% dextran T500 and oxybuprocaine were instilled for 30 minutes. Finally, ultraviolet A irradiation to the central 7.5 mm of the cornea was applied for 30 minutes, while riboflavin was instilled every 5 minutes. RESULTS: Mean corrected distance visual acuity improved by 0.036 logMAR after CXL and worsened by 0.039 logMAR in the control eyes (P<.05). Safety index was 1.05 after CXL and 0.96 in the control group. Mean spherical equivalent refraction decreased by 0.35 D (less myopic) after CXL and increased by 0.83 diopters (D) in the control eyes (P<.05). Mean apex curvature on tangential videokeratography increased by 0.51 D after CXL and by 1.61 D in the control eyes (P=.16). Mean average simulated keratometry decreased by 0.10 D after CXL and increased by 0.88 D in the control eyes (P<.05). Mean index of surface variance increased (worsened) by 0.9 after CXL and 5.3 in the control eyes (P<.05). Mean endothelial cell density was unchanged. CONCLUSIONS: A limited but favorable effect of transepithelial CXL was noted on keratoconic eyes, without complications. The effect appears to be less pronounced than described in the literature after CXL with de-epithelialization.

Topical anesthesia in strabismus surgery: a review of 101 cases.

PURPOSE: To analyze the results over a 10-year period with a different type of strabismus surgery performed with topical anesthesia, to describe the differences in technique compared with surgery performed with general anesthesia, and to detail current indications and technical changes made according to the experience accrued during these years. METHODS: A total of 101 patients undergoing strabismus surgery with topical anesthesia in a single hospital were analyzed. These patients were randomly selected from a total of 567 patients who had undergone extra-ocular muscle surgery in the past 10 years. RESULTS: A good result was obtained (squint angle < 10 prism diopters and absence of diplopia) in 95% of patients immediately after surgery and in 85% at final follow-up (mean follow-up: 3.1 years). The mean operating time for each muscle was 29 minutes. Surgery was well tolerated in every patient. Conversion to general anesthesia was not necessary in any case. Atropine was used in three patients (3%) because of induction of the vagal reflex. CONCLUSION: Topical anesthesia in strabismus surgery is a useful technique in the treatment of extraocular muscle pathology, with few limitations. Appropriate monitoring by an anesthetist is vital to ensure adequate control of pain and possible side effects and to enable conversion to general anesthesia. The oculocardiac reflex is infrequent. For experienced strabismus surgeons, the total surgical time is comparable with topical and general anesthesia.