REPLACEMENT OF LIDOCAINE GEL WITH TOPICAL PROPARACAINE ANESTHESIA FOR ROUTINE INTRAVITREAL INJECTIONS: A Comparative Study.

PURPOSE: Lidocaine gel was suggested to be highly effective in providing anesthesia for intravitreal injections but adverse effects include a possibility of making sterilization of the conjunctiva difficult. Hence, we wished to determine the effect of using 0.5% proparacaine drops alone over the use of 3.5% lidocaine hydrochloride gel anesthesia during office-based intravitreal injections. METHODOLOGY: This was a case-control study in patients who came routinely to the clinic for antivascular endothelial growth factor injections. Eyes were treated with one of two anesthesia modalities. A total of 216 injections in 120 patients were reviewed. One group (N = 107) underwent anesthesia with 0.5% proparacaine drops, and the control group (N = 109) received 3.5% lidocaine gel. The pain perceived after injection was graded using the numerical rating scale, and score was immediately recorded by the "masked" injecting physician. RESULTS: The mean pain score (±SD) for the proparacaine-only group versus gel group was 1.97 (±1.17) versus 1.76 (±0.92), P value = 0.3174. There was no statistical difference between the 2 groups. CONCLUSION: 3.5% lidocaine gel is not superior to 0.5% proparacaine drops as patients attained good pain control and excellent rates of overall satisfaction with proparacaine drops alone.

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.

Effect of four local anesthetics (tetracaine, proparacaine, lidocaine, and bupivacaine) on intraocular pressure in dogs.

PURPOSE: To measure IOP in animals, it is often necessary to use topical anesthetics. The use of these drugs may cause changes in IOP and interfere with the final results. To address this issue, the effects of four local anesthetics (tetracaine, proparacaine, lidocaine, and bupivacaine) on IOP were investigated in ten adult dogs. METHODS: One drop of tetracaine was instilled in the right eye of half of the dogs and in the left eye of the other dogs; normal saline was instilled in the fellow eyes. The IOP in each dog was measured before and at 0, 5, 10, 15, 20, 25, 30, and 35 min after drug instillation using an electronic rebound tonometer. The effects of the other anesthetics were studied in the same way at intervals of at least 1 week. RESULTS: After instillation of tetracaine, the IOP decreased gradually, such that after 15 min, the IOP was significantly lower than the baseline (p = 0.022) and control values (p = 0.048). Proparacaine also reduced IOP after 10 min compared to baseline values (p = 0.046), but the two other drugs, bupivacaine and lidocaine, had no significant effect on IOP. The duration of eye anesthesia was 16, 20, 22, and 34 min for tetracaine, lidocaine, bupivacaine, and proparacaine, respectively. CONCLUSION: We recommend using drugs that combine inducing longer anesthesia with producing the smallest change in IOP, such as bupivacaine and, subsequently, lidocaine. Tetracaine and proparacaine have a significant effect on IOP, and if these drugs are used, this effect should be considered.

Ocular Topical Anesthesia Does Not Attenuate Light-Induced Discomfort Using Blue and Red Light Stimuli.

Purpose: To investigate whether melanopsin-containing ophthalmic trigeminal ganglion cells provide significant input to mediate light-induced discomfort. This is done by studying the effect of ocular topical anesthesia on light-induced discomfort threshold to blue light and red light stimuli using a psychophysical approach. Method: Ten visually normal participants completed the experiment consisting of two trials: an anesthesia trial in which light stimuli were presented to both eyes following 0.5% proparacaine eye drops administration, and a placebo trial in which normal saline drops were used. In each trial, a randomized series of 280 blue and red light flashes were presented over seven intensity steps with 20 repetitions for each color and light intensity. Participants were instructed to report whether they perceived each stimulus as either "uncomfortably bright" or "not uncomfortably bright" by pressing a button. The proportion of "uncomfortable" responses was pooled to generate individual psychometric functions, from which 50% discomfort thresholds (defined as the light intensity at which the individuals perceived the stimulus to be uncomfortably bright/unpleasant 50% of the time) were calculated. Results: When blue light was presented, there was no significant difference in the light-induced discomfort thresholds between anesthesia and placebo trials (P = 0.44). Similarly, when red light was used, no significant difference in threshold values was found between the anesthesia and placebo trials (P = 0.28). Conclusions: Ocular topical anesthesia does not alter the light-induced discomfort thresholds to either blue or red light, suggesting that the melanopsin-containing ophthalmic trigeminal ganglion cells provide little or no significant input in mediating light-induced discomfort under normal physiologic conditions.

Comparison of Topical Versus Peribulbar Anesthesia for 23G Pars Plana Vitrectomy.

OBJECTIVE: To compare the safety and efficacy of topical anesthesia versus peribulbar anesthesia for 23-gauge pars plana vitrectomy. STUDY DESIGN: Randomized controlled trial. PLACE AND DURATION OF STUDY: Ophthalmology Department, Lahore General Hospital, Ameer-ud-Din Medical College, Postgraduate Medical Institute, Lahore from April 2013 to March 2016. METHODOLOGY: A total of 110 patients were equally divided (n=55) in group A (topical anesthesia) and group B (peribulbar anesthesia). In group A, pledget soaked with 0.5% proparacaine hydrochloride were placed in the superior and inferior fornices three minutes before surgery, and removed just before surgery. For group B patients, 3 ml of 0.5% bupivacaine was used for peribulbar anesthesia three minutes before surgery. Surgical time was noted from the placement of pledget in fornix till the eye pad placed in group A, and from the time of peribulbar anesthesia in group B till the eye pad placed at the end of surgery. All data was recorded in Excel sheet and p-values were calculated using online OpenEpi. RESULTS: The mean age of the patient was 56.28 ±13.76 years. Male patients were 78 (70.9%) and female patients were 32 (29.1%). Mean duration of surgery was 30.32 ±7.07 minutes and mean pain score was 2.30 ±0.98. There was a significant difference with respect to mean duration of surgery in patients who were given topical anesthesia (32.52 ±6.92 minutes) versus those given peribulbar anesthesia (28.12 ±6.57 minutes, p<0.001). Mean pain score in topical anesthesia group (3.11 ±0.89) was significantly higher as compared to peribulbar anesthesia group (2.67 ±0.91, p=0.011). CONCLUSION: Topical anesthesia is as effective as peribulbar anesthesia in terms of patient comfort and duration of surgery for 23-G pars plana vitrectomy in patients with vitreous hemorrhage.

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.

Comparison of surgeon comfort assessment during phacoemulsification using bilateral topical anesthesia versus ipsilateral topical anesthesia: a randomized controlled study.

AIM: To evaluate the effectiveness of bilateral use of topical anesthetic eye drops during phacoemulsification procedure as compared to use in one eye only. METHODS: This is a prospective double-blind randomized case study of 180 cases undergoing phacoemulsification under topical anesthesia using 0.5% proparacaine: Group 1 consisting of patients who had topical anesthetic eye drop instilled into the operating eye only and Group 2 consisting of patients who had both their eyes anesthetized using topical anesthetic eye drops. Phacoemulsification was done using standard surgical technique. Main parameters evaluated included number of intra-operative patient counseling score (IPCS), surgical comfort score (SCS), total phacoemulsification procedure time (TPPT) and total operation time (TOPT). RESULTS: A comparison of mean value of various variables between Group 1 (60; 33.3% cases) and Group 2 (120; 66.7% cases) using "t" test revealed that there was a statistically significant difference for mean SCS (78.38 ± 10.31 vs. 85.05 ± 8.70; p = 0.00), mean IPCS (12.60 ± 3.11 vs. 6.63 ± 1.74; p = 0.00) and mean TOPT (418.88 ± 89.59 vs. 341.64 ± 79.51; p = 0.00), respectively. However, no statistically significant difference existed for mean TPPT (143.57 ± 87.96 vs. 152.96 ± 78.99; p = 0.48). CONCLUSION: Simultaneous instillation of topical anesthetic eye drops in both the eyes, i.e., operating eye and the fellow eye as against practice of instilling topical anesthetic eye drop in the operating eye only, helps in decreasing the total surgical time by primarily shortening the durations of pre- and post-ultrasonic periods of surgery where effective globe stabilization is wanted. This is achieved by better patient compliance, which in turn enhances surgeon's comfort during phacoemulsification surgery.

Central Connections of the Lacrimal Functional Unit.

PURPOSE: To study the contribution of each eye to the reflex tear response, after unilateral and bilateral topical anesthesia. METHOD: A closed-eye, modified Schirmer test was performed bilaterally in 8 normal subjects, in a controlled environment chamber set to 23°C, 45% relative humidity, and 0.08 m/s airflow. Eye drops were instilled into each eye 10 minutes before the Schirmer test. Experiments were as follows: 1) bilateral saline (control), 2) unilateral anesthesia (ipsilateral anesthetic; contralateral saline), and 3) bilateral anesthesia. RESULTS: There was no difference in between-eye wetting lengths in the saline control eyes (P = 0.394) or the bilaterally anesthetized eyes (P = 0.171). The wetting length was reduced in both eyes after bilateral anesthesia compared with saline controls (P = 0.001; P ≤ 0.0005). After unilateral anesthesia, the wetting length was reduced in the anesthetized eye compared with its saline control by 51.4% (P ≤ 0.0005) and compared with its fellow, unanesthetized eye (P = 0.005). The fellow eye value was also reduced compared with its saline control (P = 0.06). CONCLUSIONS: The wetting length was reduced by topical anesthesia, when instilled bilaterally and ipsilaterally. The latter response implies an ipsilateral, reflex sensory drive to lacrimal secretion. In the unanesthetized fellow eye, the reduction compared with its saline control was not quite significant. This implies a relative lack of central, sensory, reflex cross-innervation, although the possibility cannot entirely be ruled out. These results are relevant to the possibility of reflex lacrimal compensation from a normal fellow eye, in cases of unilateral corneal anesthesia.

Evidence of central sensitisation in those with dry eye symptoms and neuropathic-like ocular pain complaints: incomplete response to topical anaesthesia and generalised heightened sensitivity to evoked pain.

OBJECTIVE: To evaluate how closely neuropathic-like ocular pain (NOP) symptoms align with a metric of central sensitisation (ie, the presence of persistent ocular pain after topical anaesthetic placement) in individuals with dry eye (DE) symptoms. DESIGN: Cross-sectional study of 224 individuals with DE symptoms seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding DE symptoms, NOP descriptors and evoked pain sensitivity testing on the forehead and forearm, followed by a comprehensive ocular surface examination including corneal mechanical sensitivity testing. Subsequent analyses were performed to examine for differences between those with and without ocular pain after topical anaesthetic placement. RESULTS: The mean age was 62 years with 91% being men. DE symptoms and NOP symptoms were higher in subjects with persistent ocular pain after anaesthesia. Most DE signs were not related to persistent pain, with the exception of meibum quality. Individuals with persistent ocular pain also demonstrated greater sensitivity to evoked pain at testing sites on the forehead and forearm. When examining receiver operator characteristic curves considering persistent pain as a gold standard for central sensitisation within the corneal pathway, intensity of ocular pain ratings, Ocular Surface Disease Index scores and sensitivity to light provided the most robust relationships, each with an area under the curve of 0.72. CONCLUSIONS: Individuals with DE symptoms and persistent ocular pain after topical proparacaine (a marker of central sensitisation to pain) more frequently report NOP-like symptoms and demonstrate increased sensitivity to evoked pain.

Corneal anesthetic effect and ocular tolerance of 3.5% lidocaine gel in comparison with 0.5% aqueous proparacaine and 0.5% viscous tetracaine in normal canines.

OBJECTIVE: To compare the degree and duration of corneal anesthesia of a novel viscous ophthalmic lidocaine hydrochloride preparation vs. two commonly used ophthalmic anesthetic preparations. METHODS: Each subject was randomly selected to receive 2 of 4 treatments at 2 different time periods separated by a 1 week washout: 3.5% lidocaine hydrochloride gel (Akten® ; Akorn Inc., Lake Forest, Illinois, USA), 0.5% aqueous proparacaine hydrochloride (Akorn Inc.), 0.5% viscous tetracaine hydrochloride (TetraVisc™; Ocusoft Inc., Richmond, Texas, USA), or 0.9% saline eyewash as a negative control. Corneal sensitivity was determined using a Cochet-Bonnet aesthesiometer (Luneau® , Chartres Cedex, France) prior to instillation of each treatment; at 1 and 5 min post treatment; and at 5-min intervals thereafter for 90 min total. Ocular side effects were recorded on a scale of 0-3. RESULTS: Twenty-four normal dogs (48 eyes) were entered into the study. Mean duration of maximal anesthesia was significantly greater at 34.2 min with tetracaine compared to 21.5 min and 19 min with proparacaine and lidocaine respectively. Corneal sensitivity was significantly decreased from baseline for up to 70 min with tetracaine and 55 min with both proparacaine and lidocaine. All lidocaine-treated eyes had transient blepharospasm and conjunctival hyperemia. Ten out of 24 tetracaine-treated eyes had conjunctival hyperemia with 4 of these having concurrent chemosis. CONCLUSIONS: Tetracaine provided a significantly longer duration of corneal anesthesia than proparacaine or lidocaine. Tetracaine and lidocaine were associated with more ocular side effects than proparacaine, although these were mild and transient. None.

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.

Comparison of 3 different anesthetic approaches for intravitreal injections: a prospective randomized trial.

PURPOSE: To compare the anesthetic effectiveness of topical proparacaine drops, subconjunctival lidocaine, and 2% lidocaine gel. METHODS: Ninety-two patients undergoing intravitreal injections were randomized to 1 of 3 groups: proparacaine 0.5% drops (Group Drops), proparacaine 0.5% drops plus subconjunctival lidocaine (Group SC), or 2% lidocaine gel (Group Gel). Patients were asked to score their pain experience using a visual analog scale of 0 to 10 immediately following the injections and 10 min, 1 h, 6 h, and 24 h after the injections. Patients also graded the overall injection experience as Excellent, Very Good, Fair, Poor, or Awful. The physician evaluated the patients' eye movement during intravitreal injection on 3 levels: (0) none or minimal, (1) not compromising the injection, and (2) compromising the injection. RESULTS: The patients in Group Drops had the worst mean pain scores during the injection and 10 min after, with the highest occurrence of movements compromising the procedure (Grade 2; 38.7%). The patients in Group SC had a higher percentage of good experiences (37.9%) but a higher incidence of chemosis (16.7%). The patients in Group Gel had similar overall pain scores to Group Drops patients but a higher incidence of keratitis (19.4%). There was no statistically significant correlation between the use of aspirin or anticoagulants and the occurrence of hyperemia or hyposphagma. CONCLUSION: Subconjunctival lidocaine was most effective in preventing pain and eye movements during intravitreal injections. Although 2% lidocaine gel produced a good overall experience for the patients, the incidence of keratitis was very high (19.4%). Therefore, we do not recommend 2% lidocaine gel as the first anesthetic choice for intravitreal injections. There is no evidence to suspend the use of aspirin or other anticoagulants drugs prior to intravitreal injections.

Comparison of 3 different anesthetic approaches for intravitreal injections: a prospective randomized trial / Comparação de três abordagens anestésicas diferentes para injeções intravítreas: um estudo prospectivo e randomizado

Purpose: To compare the anesthetic effectiveness of topical proparacaine drops, subconjunctival lidocaine, and 2% lidocaine gel. Methods: Ninety-two patients undergoing intravitreal injections were randomized to 1 of 3 groups: proparacaine 0.5% drops (Group Drops), proparacaine 0.5% drops plus subconjunctival lidocaine (Group SC), or 2% lidocaine gel (Group Gel). Patients were asked to score their pain experience using a visual analog scale of 0 to 10 immediately following the injections and 10 min, 1 h, 6 h, and 24 h after the injections. Patients also graded the overall injection experience as Excellent, Very Good, Fair, Poor, or Awful. The physician evaluated the patients’ eye movement during intravitreal injection on 3 levels: (0) none or minimal, (1) not compromising the injection, and (2) compromising the injection. Results: The patients in Group Drops had the worst mean pain scores during the injection and 10 min after, with the highest occurrence of movements compromising the procedure (Grade 2; 38.7%). The patients in Group SC had a higher percentage of good experiences (37.9%) but a higher incidence of chemosis (16.7%). The patients in Group Gel had similar overall pain scores to Group Drops patients but a higher incidence of keratitis (19.4%). There was no statistically significant correlation between the use of aspirin or anticoagulants and the occurrence of hyperemia or hyposphagma. Conclusion: Subconjunctival lidocaine was most effective in preventing pain and eye movements during intravitreal injections. Although 2% lidocaine gel produced a good overall experience for the patients, the incidence of keratitis was very high (19.4%). Therefore, we do not recommend 2% lidocaine gel as the first anesthetic choice for intravitreal injections. There is no evidence to suspend the use of aspirin or other anticoagulants drugs prior to intravitreal injections. .

Objetivo: Comparar a eficácia anestésica entre proparacaína tópica, lidocaína subconjuntival e lidocaína gel a 2%. Métodos: Noventa e dois pacientes em tratamento com injeções intravítreas foram randomizados para um de três grupos: proparacaína 0,5% gotas (Grupo gotas), proparacaína 0,5% gotas seguida de lidocaína subconjuntival (Grupo SC), ou lidocaína gel a 2%. (Grupo Gel). Os pacientes foram orientados a graduar a sua experiência de dor por uma escala visual analógica, numa escala de 0 a 10, imediatamente após as injeções, bem como 10 minutos, 1 hora, 6 horas e 24 horas após. Os pacientes também classificaram a experiência global de injeção como excelente, muito boa, regular, ruim ou horrível. O médico avaliou o movimento do olho do paciente durante a injeção intravítrea em três níveis: nenhuma ou mínima (0), não comprometendo a injeção (1), comprometendo a injeção (2). Resultados: Os pacientes do grupo gotas apresentaram uma graduação média de dor pior durante a injeção e 10 minutos após, com maior ocorrência de movimentos comprometendo a injeção (grau 2) (38,7%). Os pacientes do grupo SC, apresentaram maior percentual de boa experiência durante o procedimento (37,9%) e maior ocorrência de quemose (16,7%). Os pacientes do grupo Gel apresentaram escore de dor geral semelhante ao grupo Gotas e maior incidência de ceratite (19,4%). Não houve correlação estatisticamente significativa com o uso de aspirina ou anticoagulantes e a ocorrência de hiperemia ou hiposfagma. Conclusão: Lidocaína subconjuntival foi mais eficaz na prevenção da dor durante injeção intravítrea com movimentação ocular mínima. Embora os pacientes do grupo lidocaína gel a 2% tenham apresentado uma boa experiência, consideramos a incidência ceratite muito elevada (19,4%) e não recomendamos lidocaína gel a 2% como a primeira escolha como anestésico para injeções intravítreas. Não há evidência para a suspensão do uso de aspirina ou drogas anti-coagulantes em pacientes ...

The effect of repeated measurements and the use of topical anesthetic on rebound tonometry values in children.

Measurement of intraocular pressure (IOP) in children is important in the management of pediatric glaucoma. Availability of the Icare rebound tonometer has greatly facilitated our ability to obtain awake IOP in infants and children, but little has been reported on either the effect of repeated sequential IOP measurements with Icare or the effect of topical anesthetic on subsequent Icare tonometry. This prospective study of 20 eyes of 10 cooperative children (12 normal eyes, 8 with suspected or known glaucoma) found that neither 8 sequential Icare measurements nor application of topical anesthetic produced a statistically or clinically signficant change in measured IOP by rebound tonometry.

Proparacaine hydrochloride topical drop and intracameral 0.5% lignocaine for phacotrabeculectomy in patients with primary open angle glaucoma.

AIM: To compare the efficacy and safety of 0.5% intracameral lignocaine to 1% intracameral lignocaine prior to phacotrabeculectomy. STUDY DESIGN: Prospective, comparative, observational, and interventional study. SETTING: Tertiary eye care center in central India. MATERIALS AND METHODS: This study was comprised of 79 patients (79 eyes) with primary open angle glaucoma scheduled for phacotrabeculectomy. Patients were assigned to 1 of 2 Groups receiving proparacaine 0.5% eye drops and 1% intracameral lignocaine just prior to phacotrabeculectomy (Group 1, n = 39) and 0.5% intracameral lignocaine after completion of phacoemulsification just prior to trabeculectomy (Group 2, n = 40). The visual analogue scale was used to record intraoperative and postoperative pain. Patient comfort, intraoperative painful sensations perceived by the patient, supplemental anesthesia, complications, and surgeon discomfort were noted. An anesthetist also noted the vital parameters and the requirement for intravenous medications. RESULTS: There was no significant difference in the intraoperative pain score (P = 0.0733) or supplemental anesthesia (P = 0.372) between Groups. Postoperative pain score was statistically significant in Group 2 (P < 0.0001). The overall operating conditions in both Groups were comparable (P = 0.7389). A greater number of patients in Group 2 (88.57%) preferred the same anesthetic technique for combined surgery in the fellow eye. There was no difference in inadvertent eye movements and lid squeezing between Groups and they did not interfere with surgery. CONCLUSION: Topical anesthetic drops supplemented with 0.5% intracameral lignocaine before performing trabeculectomy is as effective as 1% intracameral lignocaine given at the beginning of phacotrabeculectomy for primary open angle glaucoma.

A single drop of 0.5% proparacaine hydrochloride for uncomplicated clear corneal phacoemulsification.

PURPOSE: The purpose of this study was to compare the efficacy of a single drop of 0.5% proparacaine hydrochloride in uncomplicated cataract surgery with phacoemulsification. MATERIALS AND METHODS: Two hundred and ninety five patients scheduled for the phacoemulsification were divided into 2 groups based on the anesthetic agents they were to receive: 146 patients who received a single drop of 0.5% proparacaine 2 min before the start of the surgery (proparacaine group) and; 149 patients who received supplementation of 0.5% intracameral preservative free xylocaine (xylocaine group). A single surgeon performed all surgeries. Intraoperative and post-operative pain scores were evaluated on a visual analog scale. The surgeon noted his subjective impression of corneal clarity, discomfort while performing the surgery any supplemental anesthesia required and intraoperative complications. An anesthetist noted vital parameters and the need for intravenous sedation. Total surgical time was noted. Comparison of parameters was performed with the Chi-square test, and A P value less than 0.05 was considered as statistically significant. RESULTS: No statistically significant difference was seen in the intraoperative (P = 0.24) and post-operative (P = 0.164) pain scores between groups. There was no pain (0 score) in 41.8% of patients in the proparacaine group and 46.3% of patients in the xylocaine group. The average surgical time (P = 0.279) and surgeon discomfort (P = 0.07) were not statistically significantly different between groups. No patients required supplemental anesthesia. There were no surgical complications that could compromise the visual outcome. An equal number of patients in both groups preferred same type of anesthetic technique for the fellow eye cataract surgery (89.11% for the proparacaine group and 90.18% for the xylocaine group). No patients in either group had changes in vital parameters or required intravenous sedation. CONCLUSION: A single drop pre-operatively, of proparacaine hydrochloride was comparable to the intracameral supplementation of preservative free xylocaine for phacoemulsification in uncomplicated cataract surgery without compromising the visual outcome. However, we recommend individualizing the anesthetic technique according to the requirements of the surgeon.

Comparison of efficacy and duration of effect on corneal sensitivity among anesthetic agents following ocular administration in clinically normal horses.

OBJECTIVE: To compare efficacy and duration of effect on corneal sensitivity of 0.5% proparacaine hydrochloride, 0.5% bupivacaine hydrochloride, 2% lidocaine hydrochloride, and 2% mepivacaine hydrochloride solutions following ocular administration in clinically normal horses. ANIMALS: 68 clinically normal horses. PROCEDURES: 60 horses were assigned to receive 1 anesthetic agent in 1 eye. For each of another 8 horses, 1 eye was treated with each of the anesthetic agents in random order with a 1-week washout period between treatments. Corneal sensitivity was assessed via corneal touch threshold (CTT) measurements obtained with a Cochet-Bonnet aesthesiometer before and at 1 minute, at 5-minute intervals from 5 to 60 minutes, and at 10-minute intervals from 60 to 90 minutes after application of 0.2 mL of anesthetic agent. General linear mixed models were fitted to the CTT data from each of the 2 experimental groups to assess the effects of the anesthetic agents over time, accounting for repeated observations within individual horses. RESULTS: Corneal sensitivity decreased immediately following topical application of each anesthetic agent; effects persisted for 35 minutes for proparacaine and mepivacaine treatments, 45 minutes for lidocaine treatment, and 60 minutes for bupivacaine treatment. Maximal CTT reduction was achieved following application of bupivacaine or proparacaine solution, whereas mepivacaine solution was least effective. CONCLUSIONS AND CLINICAL RELEVANCE: Ocular application of each evaluated anesthetic agent reduced corneal sensitivity in horses; although 0.5% proparacaine or 2% lidocaine solution appeared to induce adequate short-duration corneal anesthesia, use of 0.5% bupivacaine solution may be more appropriate for procedures requiring longer periods of corneal anesthesia.

Effects of action of proparacaine and tetracaine topical ophthalmic formulations on corneal sensitivity in horses.

OBJECTIVE: To compare the corneal anesthetic effects and duration of action of 2 ophthalmic anesthetic agents in horses. DESIGN: Prospective, randomized masked crossover study. ANIMALS: 8 clinically normal adult horses. PROCEDURES: Corneal sensitivity was determined by measuring each eye's corneal touch threshold (CTT) with a Cochet-Bonnet esthesiometer. Each eye's baseline CTT was recorded prior to anesthetic instillation at 0 minutes and every 10 minutes thereafter for 60 minutes. Each eye was randomly assigned to receive 2 of 4 treatments: 0.5% aqueous proparacaine ophthalmic solution (aqueous proparacaine; 8 eyes); 0.5% aqueous tetracaine ophthalmic solution (aqueous tetracaine; 8 eyes); 0.5% viscous tetracaine ophthalmic solution (viscous tetracaine; 8 eyes); and saline (0.9% NaCl) eyewash solution (8 eyes) as a negative control. There was a 48-hour washout period. Every horse received all treatments. RESULTS: Median baseline CTT of eyes was 4.5 cm (range, 0.5 to 6 cm). Median CTT for saline solution-treated eyes never differed significantly from baseline. The maximum anesthetic effect with the other 3 treatments occurred at 10 minutes. Median CTT of eyes at 10 minutes was 0.5 cm (range, 0 to 2.5 cm) with aqueous proparacaine treatment, 0.25 cm (range, 0 to 2.0 cm) with aqueous tetracaine treatment, and 0 cm (range, 0 to 0.5 cm) with viscous tetracaine treatment. Maximum anesthetic duration was 20 minutes with aqueous proparacaine and aqueous tetracaine treatments and 30 minutes with viscous tetracaine treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment of eyes with viscous tetracaine resulted in the greatest decrease in CTT and the longest duration of action, compared with treatment with aqueous proparacaine or aqueous tetracaine.

Combined topical and intracameral anesthesia for Descemet's stripping automated endothelial keratoplasty.

To evaluate the use of combined topical and intracameral anesthesia for Descemet's stripping automated keratoplasty (DSAEK). This was a retrospective comparative cohort analysis consisting of 10 eyes in 10 consecutive patients undergoing DSAEK surgery with combined topical and intracameral anesthesia. These cases were compared with 21 randomly selected controls during the same time period undergoing DSAEK surgery performed under retrobulbar anesthesia. Incidence of intraoperative and postoperative complications, and endothelial cell counts were compared. In all cases, DSAEK was completed without intraoperative complications. All patients tolerated the procedure well. There were 6 cases of postoperative graft dislocation requiring rebubbling, and no cases of primary failure or endophthalmitis. No significant difference in endothelial cell counts was found at final follow-up. Short-term results suggest that combined topical and intracameral anesthesia is as safe and effective for DSAEK in cooperative patients when compared to retrobulbar anesthesia. It may thereby be an alternative anesthetic modality for patients in whom retrobulbar or peribulbar anesthesia may be risky or contraindicated.

Randomized double-masked controlled trial comparing pain scores with and without the use of supplementary 2% lidocaine gel in LASIK.

PURPOSE: To compare pain scores with and without supplementary topical 2% lidocaine gel in patients undergoing simultaneous bilateral laser-assisted in situ keratomileusis (LASIK) under topical anesthesia using 0.5% proparacaine eye drops. DESIGN: Randomized double-masked placebo-controlled trial. METHODS: Fifty-one Chinese subjects (102 eyes, with 51 eyes in each arm) were included. One eye was randomly allocated to have supplementary 2% lidocaine gel while the other eye received carbomer gel as control, in addition to topical 0.5% proparacaine. The pain scores for each eye during microkeratome flap creation, during laser ablation, and at 15, 30, and 45 minutes after LASIK were assessed. An overall pain score of the LASIK procedure was also obtained. Primary outcome measures were pain scores during and after LASIK. Secondary outcomes included need for additional topical anesthesia, patient cooperation score, and duration and complications of surgery. RESULTS: In the 2% lidocaine gel-treated group, the pain scores were significantly lower during microkeratome flap creation and laser ablation, and postoperatively at 30 and 45 minutes (P<.05 for all). Patients in the lidocaine gel group required less additional topical anesthesia (P=.0004) and were more cooperative (P=.019) as compared to the carbomer gel group. No surgical or postoperative complications were observed. CONCLUSIONS: The use of supplementary 2% lidocaine gel in LASIK is effective in lowering the pain experienced during and up to 45 minutes after LASIK.