Intraocular penetration of topical lidocaine 4%.

PURPOSE: To evaluate the intraocular penetration of lidocaine 4% topically applied before phacoemulsification. SETTINGS: Institute of Ophthalmology, University of Verona, and Department of Medical Pharmacology, University of Padua, Italy. METHODS: Thirty eyes having phacoemulsification for senile cataract were anesthetized by topical application of lidocaine 4%. The drug was applied 3 times in 30 minutes in 15 eyes and 6 times in 60 minutes in 15 eyes. At the beginning of surgery, aqueous humor samples were obtained to measure the lidocaine levels. Blood samples were obtained in 6 patients 30 and 60 minutes after aqueous humor collection. The aqueous humor levels were compared with the amount of pain perceived by patients during surgery. RESULTS: Mean aqueous humor lidocaine concentration was 8.68 micrograms/mL +/- 2.43 (SD) after 3 instillations and 23.21 +/- 8.87 micrograms/mL after 6 instillations. Blood levels of lidocaine were negligible. Patients whose intraocular level was below 12 micrograms/mL perceived more pain during surgery. Only 2 eyes had these low levels after 6 instillations. CONCLUSIONS: Topically applied lidocaine 4% effectively penetrates the eye, providing analgesia for phacoemulsification. We suggest at least 6 instillations in the hour preceding surgery. In this study, pain during surgery was primarily related to poor intraocular levels of the anesthetic agent.     

Aqueous humor levels of topically applied levofloxacin, norfloxacin, and lomefloxacin in the same human eyes

PURPOSE: To assess the relative penetration of topical eyedrops of 3 fluoroquinolones into the aqueous humor in human eyes. SETTING: Department of Ophthalmology, Sano-Kosei Hospital, Sano, Japan. METHODS: Fifty-nine cataract patients (36 women, 23 men) received 3 drops each of levofloxacin 0.5%, norfloxacin 0.3%, and lomefloxacin 0.3% in the same eye at 15-minute intervals beginning 90 minutes before cataract surgery. At the beginning of surgery, 50 microL of aqueous humor was aspirated from the anterior chamber and stored at -80 degrees C until analyzed. The drug concentrations in the samples were analyzed using high-performance liquid chromatography. RESULTS: Five patients were excluded from the study because their sample volumes were insufficient. Norfloxacin was detected in 3 patients; the mean aqueous humor level was 0.10 microg/mL +/- 0.02 (SD). Levofloxacin was detected in all cases; the mean aqueous humor level was 0.60 +/- 0.28 microg/mL (n = 54). Lomefloxacin was not detected in 10 patients; the mean aqueous humor level was 0.23 +/- 0.11 microg/mL (n = 44). CONCLUSION: Topically applied levofloxacin had better penetration into the aqueous humor than lomefloxacin and norfloxacin.     

Subjective visual experience and pain level during phacoemulsification and intraocular lens implantation under topical anesthesia

PURPOSE: To investigate the subjective visual experiences and pain during the phacoemulsification and intraocular lens (IOL) implantation under topical anesthesia, and whether these parameters change according to the stage of phacoemulsification cataract surgery. METHODS: Forty eyes of 40 patients with cataract undergoing phacoemulsification and IOL implantation under topical anesthesia were included in this study. The patients were told that they would be asked about their visual experiences and pain level, if any, during every stage of the surgery. As for degree of the pain, a 5-grade scale was used. The surgery was divided into 9 stages, i.e., clear corneal incision, continuous curvilinear capsulorhexis, side-port incisions at 3 and 9 o'clock positions, hydrodissection, nuclear rotation, phacoemulsification, bimanual irrigation and aspiration, IOL implantation, apposition of corneal incisions with stromal hydration. RESULTS: All subjects (100%) reported that they had seen some kind of light during the operation. Thirty-eight patients (95%) said that they had seen one or more colors. In 32 patients (80%), the light intensity decreased, and colors blurred significantly following the hydrodissection. As for the pain level during surgery, the overall pain score was found to be 0.40. The highest mean pain score was noted during IOL implantation stage followed by phacoemulsification and bimanual irrigation-aspiration. CONCLUSION: Topical anesthesia is both a safe and effective method for small-incision clear corneal phacoemulsification cataract surgery. Patients may experience visual sensations, and the pain felt during the operation is low and tolerable. Visual experiences and pain level may change according to the stage of phacoemulsification cataract surgery.     

Patient pain during different stages of phacoemulsification using topical anesthesia.

PURPOSE: To assess the pain experienced by patients during the different stages of phacoemulsification cataract surgery performed under topical anesthesia. SETTING: Ophthalmic teaching hospital, Dublin, Ireland. METHODS: This prospective study comprised 100 consecutive patients having phacoemulsification under topical anesthesia. Patients were asked to grade the pain they experienced during the different stages of the procedure using a visual analog pain scale from 0 to 10. The pain experienced during the procedure was compared with that experienced after the instillation of a drop of amethocaine. RESULTS: The overall mean pain score was 1.46. The highest mean pain score, which was during the phacoemulsification stage of the procedure, was not significantly more than the score for the administration of the topical anesthetic agent. The duration of surgery was not related to the level of pain during the procedure. CONCLUSIONS: Topical anesthesia was effective in phacoemulsification cataract surgery. Because the highest mean score was not significantly higher than that for the administration of the anesthetic agent, it is possible to counsel patients before surgery that the pain they experience during the procedure will be no worse than that during administration of the anesthetic drops.     

Penetration of topically applied ciprofloxacin and ofloxacin into the aqueous humor and vitreous

PURPOSE: To determine the intraocular penetration of topical drops of 2 antibiotics, ciprofloxacin 0.3% and ofloxacin 0.3%, into the aqueous humor and vitreous and to relate these levels to the miminum inhibitory concentration (MIC(90)) for organisms associated with ocular bacterial infections. SETTING: Department of Ophthalmology, Ankara Hospital, and Department of Pharmacology, Faculty of Medicine, Hacettepe University, Ankara, Turkey. METHODS: This prospective randomized clinical trial comprised 18 patients having cataract surgery, all with an intact corneal epithelium. The patients were randomly assigned to receive topical ciprofloxacin 0.3% (n = 10) or topical ofloxacin 0.3% (n = 8) 1 drop every 15 minutes 5 times and every 30 minutes 3 times before surgery. Aqueous and vitreous samples (if vitreous loss occurred during the cataract surgery) were collected 30 minutes after the administration of the last dose. Drug concentrations were determined by high-performance liquid chromatography (HPLC) fluorescence. RESULTS: All patients had detectable drug concentrations in the aqueous humor and vitreous measurable by HPLC. The mean aqueous humor concentration of ciprofloxacin was 1.13 microg/mL +/- 1.90 (SD) and the mean vitreous concentration, 0.23 +/- 0.06 microg/mL. Topical administration of ciprofloxacin yielded 4.9 times more drug concentration in the anterior chamber than in the vitreous. The mean aqueous concentration of ofloxacin was 2.06 +/- 1.06 microg/mL and the mean vitreous concentration, 0.46 +/- 0.10 microg/mL. Topical administration of ofloxacin yielded 4.7 times more drug concentration in the anterior chamber than in the vitreous. Aqueous humor concentrations of ofloxacin and ciprofloxacin were not statistically significantly different (P =.353). Intravitreal concentrations of ofloxacin were statistically significantly higher than those of ciprofloxacin (P =.001). CONCLUSIONS: Topical ofloxacin 0.3% penetrated better than topical ciprofloxacin 0.3% into the anterior chamber and vitreous in noninflamed eyes. Both drugs were above the MIC(90) for most ocular pathogens in the anterior chamber. The mean concentration in the vitreous of topically applied ofloxacin 0.3% was statistically significantly higher than that of ciprofloxacin 0.3%, but it was not sufficiently above the MIC(90) for most ocular pathogens in terms of empirical endopthalmitis therapy.     

Cataract surgery under topical anesthesia in patients with coexisting glaucoma

PURPOSE: To evaluate and compare levels of patient discomfort and complications during phacoemulsification with implantation of a foldable intraocular lens (IOL) under topical lidocaine hydrochloride in patients with and without various forms of chronic open-angle and chronic angle-closure glaucoma. SETTING: Two university eye centers in Germany. METHODS: This prospective nonrandomized comparative study comprised 176 eyes of 176 patients with various forms of chronic open-angle glaucoma and chronic angle-closure glaucoma. Eyes with cataract and without a glaucoma diagnosis or history of intraocular surgery served as a control group (n = 212). All patients received a minimum of 5 doses (2 drops per dose) of topical lidocaine hydrochloride 2% before standard temporal clear corneal phacoemulsification and foldable IOL implantation. No intracameral anesthetic injection was given, and no systemic sedatives were used. The main outcome measures were the number of complications and adverse events. RESULTS: The intraoperative complication rate in all patients (n = 388) was capsule tear, 1.3%; zonule tear, 1.8%; vitreous loss, 1.0%; iris prolapse, 0.8%. No statistically significant differences in intraoperative or early postoperative complications were found between the glaucoma and control groups. The mean pain scores of patients were 0.38 +/- 1.1 (SD) in the glaucoma group and 0.36 +/- 0.8 in the control group (P =.21) Patient preference for cataract surgery under topical anesthesia was similar in both groups. CONCLUSIONS: Surgery-related complications and patient discomfort were similar in patients with and without glaucoma who had phacoemulsification and IOL implantation under topical anesthesia. These results indicate that topical anesthesia is safe for routine phacoemulsification with foldable IOL implantation in patients with glaucoma and does not compromise patient comfort.     

Comparative clinical trial of topical anesthetic agents in cataract surgery: lidocaine 2% gel, bupivacaine 0.5% drops, and benoxinate 0.4% drops

PURPOSE: To assess the efficacy of lidocaine gel, bupivacaine drops, and benoxinate drops as topical anesthetic agents in cataract surgery. SETTING: Kasr El-Aini Hospital, Cairo University, Cairo, Egypt. METHODS: This prospective randomized study comprised 90 patients scheduled for routine cataract extraction. Patients were randomized into 3 groups of 30 each based on which anesthetic agent they received: lidocaine 2% gel, bupivacaine 0.5% drops, or benoxinate 0.4% drops. Subjective pain at application of the agent and intraoperatively was quantified by the patients using a verbal pain score (VPS) scale from 0 to 10. The duration of discomfort at application, duration of surgery, rate of supplemental sub-Tenon's anesthesia, and complications were recorded. RESULTS: The mean VPS at application was 2.97, 1.53, and 1.03 in the lidocaine, bupivacaine, and benoxinate groups, respectively; the VPS in the lidocaine group was statistically significantly higher than in the other 2 groups (P<.001). The mean duration of pain at application was 25 seconds, 14 seconds, and 6 seconds in the lidocaine, bupivacaine, and benoxinate groups, respectively, and was statistically significantly higher in the lidocaine group (P<.001). The mean VPS during surgery was 1.6, 4.1, and 7.1 in the lidocaine, bupivacaine, and benoxinate groups; the lidocaine group had a statistically significantly lower mean VPS than the other 2 groups (P<.001). The incidence of supplemental sub-Tenon's injection was 3.3%, 10.0%, and 73.3%, respectively, and was statistically significantly lower in the lidocaine and bupivacaine groups than in the benoxinate group (P<.001). The patients' overall satisfaction was statistically significantly higher in the lidocaine and bupivacaine groups than in the benoxinate group (93.3%, 83.3%, and 33.3%, respectively) (P<.001). Three patients in the lidocaine group had corneal haze at the time of surgery, which was not statistically significant (P>.1). CONCLUSIONS: Lidocaine gel was a better topical anesthetic agent than bupivacaine and benoxinate drops. Bupivacaine drops were effective in providing deep topical anesthesia.     

Patient's pain feeling and surgeon's comfort--ECCE versus phacoemulsification

PURPOSE: To compare patient's pain and surgeon's comfort during ECCE performed under retrobulbar anesthesia and phacoemulsification under topical anesthesia. MATERIAL AND METHODS: 120 patients scheduled for planned routine cataract extraction were divided in 2 groups: group 1-60 eyes, ECCE under retrobulbar anesthesia and group II-60 eyes, phacoemulsification under topical anesthesia. Immediately after operation patients were asked, to answer questions about their feeling during surgery. Simultaneously, the surgeon filled up the questionnaire, concerning patients behavior during the entire procedure. RESULTS: Statistically significant higher level of pain was reported in group I (ECCE). The most painful moment of the procedure was retrobulbar injection. During surgery pain feeling in both groups was similar. Both types of anesthesia provided very good level of surgeon's comfort. The longer operation, the higher level of pain and lower surgeon's comfort were reported in both groups. CONCLUSIONS: Patients having ECCE performed under retrobulbar anesthesia reported more pain comparing to phacoemulsification under topical anesthesia. Both anesthesia methods provided high level of surgeon's comfort.     

表面麻醉聯合前房麻醉行白内障超聲乳化摘除及人工晶體植入術

目的評價表面麻醉聯合前房麻醉行白内障超聲乳化摘除及人工晶體植入術的效果.方法各種白内障共37衹眼,術前15分鐘先使用1%丁卡因滴眼三次,每次1～2滴,間隔3～5分鐘.手術開始後,先作側切口,從側切口滴入2%利多卡因,0.1ml于前房内.結果分别以無痛感、輕微痛但能耐受手術及痛不能耐受手術來評價麻醉效果,術中無一例訴痛不能耐受者,四衹術眼在用齒镊爽結膜固定眼球或分開球結膜及角鞏缘切中時訴輕微疼痛.撕囊、超乳及人工晶體植入等前房内操作中一例訴眼部疼痛.結論表面麻醉聯合前房麻醉行白内障超聲乳化摘除及人工晶體植入術是可行的,可避免球後麻醉或周麻醉带來的并發癥.     

门诊白内障患者表面麻醉下透明角膜切口的超声乳化术

目的观察门诊白内障患者表麻下透明角膜切口超声乳化术的临床效果。方法临床确诊的各种白内障门诊患者143例(158只眼),在表面麻醉下经透明角膜切口,行白内障超声乳化吸除及折叠式人工晶状体植入手术。结果所有患者均能耐受手术,未发生麻醉并发症。术后第1天视力≥0.5者129只眼,占82.3%;术后1周视力≥0.5者149只眼,占94.2%。手术并发症主要有:角膜水肿、后囊破裂及结膜水肿。结论在门诊开展表麻下透明角膜切口白内障超声乳化术安全、可靠,比其它麻醉方式并发症少,术后视力恢复快,患者乐于接受。     

表麻下巩膜隧道内小梁切除联合超声乳化术

目的 评价采用表面麻醉的白内障超声乳化,人工晶状体植入联合小梁切除术的可行性、优越性。方法 观察35例青光眼合并白内障的麻醉效果,手术方法,术后视力、眼压、滤过泡。结果 35例均采用表面麻醉顺利完成手术,视力有不同提高,滤过泡形成良好。31例眼压控制。结论 白内障超声乳化,人工晶状体植入联合小梁切除术采用表面麻醉具有创伤小、术后反应轻和疗效可靠等优点。     

Aqueous humor levels of topically applied levofloxacin in human eyes

PURPOSE: To evaluate transcorneal penetration of topically applied 0.5% levofloxacin into the aqueous humor in human eyes. METHODS: Twenty cataract patients (14 females, 6 males) received 3 drops of 0.5% levofloxacin at 15 min intervals from 90 minutes before the surgery. At the beginning of the cataract surgery, 50 microL of aqueous humor was aspirated from the anterior chamber and stored at -80 degrees C until analysis. The drug concentration of the samples was analyzed using high-performance liquid chromatography. RESULTS: A mean aqueous humor level of levofloxacin was 1.00 +/- 0.48 microg/mL (mean +/- standard deviation, n = 20), ranging from 0.30 microg/mL to 2.32 microg/mL. CONCLUSIONS: The mean concentration of levofloxacin in the aqueous humor was higher than the MIC(90) values against some common pathogens of postoperative endophthalmitis, although a great degree of interpatient variability was present.     

表面麻醉下高度近视眼白内障超声乳化术初步探讨

目的：分析和探讨表面麻醉下行高度近视眼合并白内障超声乳化术的安全性及其疗效。方法：对45例50只高度近视眼合并白内障患者进行表面麻醉下超声乳化术并植入人工晶状体，观察手术中疼痛感、并发症、术后疗效及与疗效相关问题。结果：40例45只眼无疼痛，3例3只眼有轻微胀感，2例2只眼胀痛，术中追加一次表面麻醉，1例1只眼发生部分悬韧带离断，无视网膜脱离发生。结论：表面麻醉下高度近视眼合并白内障超声乳化术安全、疗效确切、并发症少。     

Pain induced by phacoemulsification performed by residents using topical anesthesia.

BACKGROUND AND OBJECTIVE: To evaluate patient-reported pain induced by phacoemulsification performed by residents using topical anesthesia. PATIENTS AND METHODS: This prospective study comprised 81 eyes of 76 consecutive patients having phacoemulsification under topical anesthesia. Surgery was performed by an experienced surgeon (group 1; n=41 eyes) or by two residents (group 2; n=40 eyes). No sedation or intracameral anesthesia was used in either group. Eighty eyes had clear corneal phacoemulsification with foldable acrylic posterior chamber intraocular lens implantation. Patients were asked postoperatively to grade the pain they experienced during the procedure using a visual analog pain scale from 0 to 10. RESULTS: The median pain score for the overall pain was 1.59 +/- 1.43 (range: 0 to 6) in group 1 and 1.95 +/- 1.64 (range: 0 to 7) in group 2 (P = .291). The mean pain score for the maximum pain perceived was 2.39 +/- 1.86 (range: 0 to 7) in group 1 and 2.53 +/- 1.67 (range: 0 to 7) in group 2 (P = .734). There was no significant correlation between the duration of surgery and the overall pain score (r = 0.102, P = .365). CONCLUSION: Topical anesthesia had sufficient analgesic effects in selected patients undergoing phacoemulsification cataract surgery by resident surgeons. The pain felt during the operation was low and tolerable.     

Topical versus sub-Tenon's anesthesia without sedation in cataract surgery.

PURPOSE: To compare pain control using topical anesthesia with that using sub-Tenon's anesthesia for clear corneal phacoemulsification cataract surgery and foldable intraocular lens (IOL) implantation. SETTING: Departments of Ophthalmology, General Hospital Asklepeion Voulas and General Hospital of Athens, University of Athens, Athens, Greece. METHODS: One hundred consecutive patients scheduled for bilateral cataract surgery 1 to 2 months apart were prospectively randomized to receive topical anesthesia (100 eyes) or sub-Tenon's anesthesia (100 eyes). The randomization was stratified so that one half of first-eye surgeries and one half of second-eye surgeries were assigned to each anesthesia group, with each patient receiving each type of anesthesia once. All patients had clear corneal phacoemulsification with foldable IOL implantation. Patients were asked to rate their pain level on a 10-point scale for 4 periods: during the administration of the anesthetic agent, during surgery, immediately after surgery, and 24 hours postoperatively. The surgeon recorded his subjective assessment of ease of surgery and surgical complications using a standardized template. RESULTS: Eighty-one percent of patients who received topical anesthesia and 8% of patients who received sub-Tenon's anesthesia reported no pain during delivery of the anesthetic agent. The mean pain score was 0.19 +/- 0.39 (SD) in the topical group and 1.35 +/- 0.63 in the sub-Tenon's group. The difference between groups was statistically significant (P <.001). Seventy-two percent of patients in the topical anesthesia group and 86% in the sub-Tenon's anesthesia group reported no pain or slight discomfort during surgery (mean score 1.13 +/- 1.57 and 0.57 +/- 1.28, respectively) (P <.001). Ninety percent of topical anesthesia patients and 100% of sub-Tenon's anesthesia patients reported no pain or slight discomfort 30 minutes postoperatively (mean score 0.80 +/- 0.93 and 0.12 +/- 036, respectively) (P <.001). All patients in the topical anesthesia group and 77% in the sub-Tenon's group reported no pain 24 hours postoperatively (mean pain 0.00 +/- 0.00 and 0.23 +/- 0.40, respectively) (P <.001). Complications including prolonged akinesia of the globe, chemosis, and conjunctival hemorrhage occurred significantly more frequently in the sub-Tenon's than in the topical group (P <.001). CONCLUSIONS: Patients having cataract surgery under topical anesthesia had more intraoperative and postoperative discomfort than patients receiving sub-Tenon's anesthesia. However, patients having topical anesthesia reported less pain during its administration and had fewer complications. Both anesthesia methods provided high levels of pain control without additional sedation.     

Circumferential perilimbal anesthesia for combined cataract glaucoma surgery

BACKGROUND AND OBJECTIVES: A topical-subconjunctival anesthesia technique named circumferential perilimbal anesthesia was tested in a consecutive series of 34 combined cataract and glaucoma cases to determine effectiveness in long duration anterior segment surgery. PATIENTS AND METHODS: The circumferential perilimbal technique for combined surgery involved administration of 4% topical Xylocaine drops and injection of 0.25 cc of 4% Xylocaine subconjunctivally 3-4 mm inferior to the limbus. The inferior subconjunctival anesthesia was then spread 360 degrees around the limbus circumferentially with a smooth forceps. The topical and local anesthetic was supplemented by intravenous preoperative and intraoperative sedative and analgesic medications. RESULTS: All patients had successful phacoemulsification cataract extraction with intraocular lens combined with trabeculectomy. Medical records and postoperative interviews of the combined cataract-glaucoma cases revealed an average surgery time of 46 minutes (range 35 minutes-60 minutes) and only one incident of patient intraoperative pain. CONCLUSION: The circumferential perilimbal technique was an effective anesthesia technique for long duration combined cataract and glaucoma surgery.     

Patient pain during stretching of small pupils in phacoemulsification performed using topical anesthesia

PURPOSE: To assess the pain experienced by patients with small pupils during pupil stretching in phacoemulsification performed using topical anesthesia. SETTING: Royal Victoria Eye & Ear Hospital and Mater Misericordiae University Hospital, Dublin, Ireland. METHODS: This was a prospective study that included 26 eyes with small pupils requiring mechanical pupil stretching during phacoemulsification cataract surgery performed under topical anesthesia without sedation. RESULTS: The mean pain score for the instillation of anesthetic drops (2.02) was higher than the mean pain score for the pupil stretch (1.63), but this difference was not significant (signed rank test = -32; P = .2738). There was no significant correlation between the duration of surgery and the overall pain score (r = 0.345; P = .08). There was no significant correlation between change in pupil size and either the pupil stretch score (r = -0.069; P = .74) or the overall pain score (r = -0.032; P = .8739). CONCLUSIONS: Pupil stretching during phacoemulsification in patients with small pupils was performed with minimal patient-reported pain using topical anesthesia. Stretching small pupils with a mechanical device during phacoemulsification performed under topical anesthesia was a safe procedure and did not result in significant patient discomfort.     

Topical anesthesia with sedation in phacoemulsification and intraocular lens implantation combined with 2-port pars plana vitrectomy in 105 consecutive cases

BACKGROUND AND OBJECTIVE: To evaluate the efficacy of topical anesthesia as an alternative to peribulbar or retrobulbar anesthesia in phacoemulsification and intraocular lens implantation combined with our modified 2-port pars plana vitrectomy technique (phacovitrectomy). PATIENTS AND METHODS: Phacovitrectomy using topical anesthesia (4% lidocaine drops) was prospectively performed in 105 eyes with cataract and varied vitreoretinal pathology. In 75 eyes (71.4%), phacovitrectomy was combined with argon laser photocoagulation (endolaser). Preoperative and intraoperative sedation of varying degrees was necessary. Subjective pain and discomfort were graded from 1 (no pain or discomfort) to 4 (severe pain and discomfort). RESULTS: All patients had grade 1 pain and discomfort during most of the procedure. All patients had grade 2 (mild) pain and discomfort during pars plana sclerotomies, external bipolar cautery, and conjunctival closure. No patient required additional retrobulbar, peribulbar, or sub-Tenon's anesthesia. CONCLUSION: This technique avoids the risk of globe perforation, retrobulbar hemorrhage, and prolonged postoperative akinesia of the eye. With appropriate case selection, topical anesthesia is a safe and effective alternative to peribulbar or retrobulbar anesthesia in phacovitrectomy.     

Anesthetic dose and analgesic effects of sub-Tenon's anesthesia in cataract surgery.

PURPOSE: To compare the analgesic effects of different doses of sub-Tenon's anesthesia in cataract surgery by assessing patient response to visceral stimulus. SETTING: Inouye Eye Hospital, Tokyo, Japan. METHODS: A prospective study was done of 1019 eyes of 1019 patients having phacoemulsification and posterior chamber intraocular lens implantation. They received a 1.0 mL (391 eyes), 2.0 mL (366 eyes), or 3.0 mL (262 eyes) anesthetic infiltration into the sub-Tenon's space. Pain scores were recorded when the anterior chamber was irrigated with an acetylcholine chloride solution to attain miosis after lens implantation. RESULTS: The distribution of pain scores was significantly different among the 3 groups (P < .0001, Kruskal-Wallis test). Multiple comparison revealed that the 3.0 mL anesthetic infiltration offered significantly higher analgesic effects than the 2 lower doses. The 3.0 mL sub-Tenon's anesthesia effectively blocked the visceral stimulus. CONCLUSION: For cataract surgery, 3 mL is the optimal dose of anesthetic solution in sub-Tenon's anesthesia.