Topical anesthesia in strabismus surgery: a review of 101 cases

Semi-adjustable posterior approach for congenital ptosis repair- outcomes of local and general anesthesia

BACKGROUND

To report a single center experience with semi-adjustable posterior approach levator plication ('levatorpexy') in patients with congenital ptosis.

MATERIALS AND METHODS

A retrospective study. All cases who underwent posterior approach levatorpexy for congenital ptosis between the years 2016 to 2022 were included. The primary outcome measures were margin-to-reflex distance 1 (MRD1) before and after surgery, upper eyelid contour, symmetry of upper eyelid height, complications, and surgical success. Surgery was successful if all the following criteria were met: A postoperative MRD1 of ≥2 mm and ≤4.5 mm, a satisfactory eyelid contour in the operated eyelid, and an inter-eyelid MRD1 asymmetry of ≤1 mm. Postoperative modifications in semi-adjustable techniques were considered in all cases.

RESULTS

Twenty-three eyelids of 21 patients were included, 11 were performed under general anesthesia, and 12 were performed under local anesthesia. The mean age of all patients was 24.1 years (8-47 years). The mean levator function was 11.2 (±2.11). Mean preoperative MRD1 was 1.05 mm and 1.41 for general and local anesthesia, respectively. Mean postoperative MRD1 was 3.33 mm and 3.37 mm for general and local anesthesia, respectively. Eighteen patients (85%) achieved the desired eyelid height and fulfilled our criteria for success. There were no complications reported in any of the groups.

CONCLUSION

Posterior approach levatorpexy is a safe and effective procedure for repairing congenital ptosis in patients with good levator function. This technique is suitable for young patients and those unable to undergo surgery under local anesthesia. This technique offers post-operative modification due to its semi-adjustable nature.

Interaction between eye movements and adhesion of extraocular muscles

The contact and pull-off tests and finite element simulations were used to study the extraocular muscle-sclera adhesion and its variation with eye movement in this research. The effect of the adhesion on the eye movements was also determined using equilibrium equations of eye motion. The contact and pull-off tests were performed using quasi-static and non-quasi-static unloading velocities. Finite element models were developed to simulate these tests in cases with high unloading velocity which could not be achieved experimentally. These velocities range from the eye's fixation to saccade movement. The tests confirmed that the pull-off force is related to the unloading velocity. As the unloading velocity increases, the pull-off force increases, with an insignificant increase at the high ocular saccade velocities. The adhesion moment between the extraocular muscles and the sclera exhibited the same trend, increasing with higher eye movement velocities and higher separation angles between the two interfaces. The adhesion moment ratio to the total moment was calculated by the traditional model and the active pulley model of eye movements to assess the effect of adhesion behavior on eye movements. At the high ocular saccade velocities (about 461 deg/s), the adhesion moment was found to be 0.53% and 0.50% of the total moment based on the traditional and active pulley models, respectively. The results suggest that the adhesion behavior between the extraocular muscles and the sclera has a negligible effect on eye movements. At the same time, this adhesion behavior can be ignored in eye modeling, which simplifies the model reasonably well. STATEMENT OF SIGNIFICANCE: 1. Adhesion behavior between the extraocular muscles and the sclera at different indenter unloading velocities determined by contact and pull-off tests. 2. A finite element model was developed to simulate the adhesive contact between the extraocular muscles and the sclera at different indenter unloading velocities. The bilinear cohesive zone model was used for adhesive interactions. 3. The elastic modulus and viscoelastic parameters of the extraocular muscle along the thickness direction were obtained by using compressive stress-relaxation tests. 4. The influence of the adhesion moment between the extraocular muscles and the sclera on eye movement was obtained according to the equation of oculomotor balance. The adhesion moment between the extraocular muscles and the sclera was found to increase with increased eye movement velocity and increased separation angle between the two interfaces.

Surgical and anesthetic influences of the oculocardiac reflex in adults and children during strabismus surgery

One of the most common untoward occurrences during strabismus surgery at all ages is the oculocardiac reflex. Although typically easily treated, the sudden bradycardia or cardiac arrest may add a few gray hairs to ophthalmologists and anesthesiologists alike as it can be potentially fatal. This updated review of the literature and novel detailed treatment algorithm may prevent patient morbidity and mortality through proper recognition of at-risk patients and rapid treatment through proper communication between surgical and anesthesia physicians/providers.

Non-adjustable surgery for acute acquired comitant esotropia under general anesthesia

Purpose:

To investigate the surgical results of the non-adjustable suture technique under general anesthesia for the correction of acute acquired comitant esotropia.

Study design:

Retrospective case study.

Methods:

Patients with acute acquired comitant esotropia who underwent corrective surgery from September 2008 to June 2018 were included. Surgical treatment was conducted based on the measured maximum angle after occlusion for at least 1 h; all surgeries were performed using the non-adjustable suture technique under general anesthesia. Motor success was categorized into three groups: good, ortho; fair, 2 to 8 prism diopters (PD); and poor, over 8 PD. Sensory success was divided into two groups: good (no diplopia with binocular vision) and poor (no stereopsis with diplopia).

Results:

40 patients (21 male and 19 female, 28.78 ± 15.32 years old) were included. Preoperative esodeviation was 28.0 ± 12.8 PD. Mean refractive error was − 2.5 ± 2.5 D (spherical equivalent). After the occlusion of one eye, 14 patients (35%) showed an esodeviation increase of more than 5 PD. There were 70% good, 25% fair, and 5% poor outcomes regarding motor success. 96% of the patients demonstrated good sensory success.

Conclusion:

The non-adjustable correction based on the maximum angle after 1 h had a relatively excellent motor and sensory success rate.

Medical expenditure for strabismus: a hospital-based retrospective survey

Background and aims

The misconception of the purpose of strabismus treatment has, on the one hand, affected the motivation of strabismus patients to seek care and, on the other hand, has resulted in strabismus not being covered by health insurance, both of which interact to limit the motivation of strabismus patients and also impose a financial burden on strabismus patients. Previous studies on the cost of strabismus had only addressed the cost utility and functional and psychosocial benefits of strabismus surgery. The aim of this study was to estimate the direct medical expenditure incurred for strabismus surgery and analyze the trend for the period 2014–2019 using the data collected by local eye hospitals in northeast China.

Methods

This study was based on 6-year strabismus medical expenditure data collected from the eye hospital of the first affiliated hospital of Harbin medical university, covering 3596 strabismus patients who had strabismus surgery. All medical expenditure data were adjusted to 2014 using China’s annual consumer price index to remove the effects of inflation.

Results

The average direct medical expenditure for strabismus cares (in 2014) was 5309.6 CNY (US$870.4), and the annual growth rates from 2015 to 2019 (compared with the previous year) were 9.3, 7.7, 21.7, 14.5, and 4.3%, respectively. Surgical expenses accounted for the highest proportion (33.1%) of the total medical expenses followed by examinations expenses (19.7%) and medical consumables expenses (18.7%). The regression coefficient for general anaesthesia was 1804.5 and age was less than 0.

Conclusion

The average direct medical expenditure for strabismus increases year by year, and the growth rate is rapid. Anesthesia was the most important factor increasing medical cost, and age was negatively correlated with cost.

Topical anaesthesia in strabismus surgery for Graves' orbitopathy: a comparative study of 111 patients

PURPOSE

To evaluate the tolerability and usability of topical anaesthesia in single rectus muscle recession for strabismus caused by Graves' orbitopathy (GO). To compare the perioperative pain score and surgical outcome between GO patients and non-GO patients.

METHODS

A retrospective comparative study of consecutive single rectus muscle recession performed under topical anaesthesia was carried out. All patients scheduled for one-stage single rectus muscle recession under topical anaesthesia were included. Numerical visual analogue pain score scale (NVAS) points, rates of motor success (horizontal deviation < 8 prism diopters (PD) and vertical deviation ≤ 6 PD) and sensory success (no diplopia without prisms), complications and postoperative adjustment frequencies were compared between GO and non-GO patients.

RESULTS

A total of 111 patients were included. The mean perioperative pain scores were 2.3 (SD ± 1.3) in GO and 1.6 (SD ± 1.1) in non-GO patients (p = 0.06 adjusted for gender). The postoperative mean alignments in GO and non-GO patients were 2 versus 3 PD horizontally and 1 versus 1 PD vertically respectively. Both motor and sensory success rates were 98% in GO patients and 94% versus 93% in non-GO patients. Adjustments as a second procedure the day after surgery was performed in 10% of the GO patients and 15% of the non-GO patients. The oculocardiac reflex was not triggered in any of the GO patients.

CONCLUSION

Topical anaesthesia in single muscle recession for GO is safe, well-tolerated and gives comparable surgical outcomes to those achieved in non-GO patients.

The Oculocardiac Reflex: A Review

BACKGROUND

A typical oculocardiac reflex (OCR) is a moderate trigemino-vagal bradycardia elicited by tension on an extraocular muscle (EOM) during strabismus surgery; however, many other orbital stimuli can elicit cardiac slowing including retinopathy of prematurity examination.

METHODS

World literature related to trigeminovagal and oculocardiac reflex covering over 15,000 patients including 51 randomized clinical trials and case reports are analyzed and reviewed. Under an ongoing observational trial in Alaska, anesthetic, patient and surgical influences on routine strabismus surgery using prospective, uniform EOM tension are compared seeking sufficient sample size to characterize this individually widely variable cardiac response.

RESULTS

With adequate sample size, and emphasizing clinical studies controlling type of EOM, muscle tension amount and duration, anticholinergic and opioid medications, the following augment OCR; rapid-acting opioids and dexmedetomidine while OCR is reduced in older patients, the right eye, less EOM tension, deeper inhaled agents, hypocarbia, anticholinergic medications and orbital block. In re-operations, the former are relatively poor predictors of subsequent OCR.

CONCLUSION

Profound bradycardia can occur in almost 10% of strabismus surgery cases without anticholinergic preventive measures, but reliable prediction of OCR remains elusive. With foreknowledge and careful anesthetic monitoring of the patient before EOM manipulation, residual adverse sequelae from OCR are fortunately very rare. Despite well over a century of experience, the teleology for this occasionally dramatic cardiac response to eye surgery is still not known.

Evaluation of single stage adjustable strabismus surgery (SSASS) under topical anesthesia in patients with symptomatic diplopia

We wish to assess effectiveness of using topical anesthesia without sedation in single-stage adjustable strabismus surgery (SSASS). Sixteen consecutive adults with diplopia and those willing to undergo SSASS, participated in a prospective study between September 2018-August 2019. They underwent detailed ophthalmic evaluation, ocular alignment measurement by prism cover test (PCT), and sensory evaluation. Subsequently they underwent SSASS under topical anesthesia (2% lidocaine gel). Surgery was performed using conventional technique; ocular alignment was then reassessed in sitting position by alternate cover test using prisms, for which with Snellen's chart was used as distance target and Lang's fixation stick as near target. Absence of diplopia was considered the end point of measurement. Any adjustment, if required, was performed intraoperatively, after recleaning the operative area with povidone iodine and redraping the eye. Participants were reassessed 1 day, 1 month, and 3-month after procedure, ocular deviation, and presence or absence of diplopia was documented. Fifteen males and one female patient participated in the study. Mean age of the study population was 31.29 years (range 19-65 years). Of these, 62.5% of patients required intraoperative modification of planned surgical dose. Patients with esotropia, vertical deviations, and combined deviations obtained surgical success, which remained stable till 3-month review. Patients with exotropia had initial surgical success rates of 100% immediately following surgery (day 1 postoperative evaluation), but it decreased to 83.33% and 66.67% during one and 3-months follow-up visits. In this study all patients tolerated the procedure well, without systemic adverse occurrence, including vasovagal reflex and without the need for additional anesthesia. SSASS is a good option in patients with diplopia and variable ocular deviations. Topical anesthesia allows intraoperative adjustment of surgical dosing, with aim of orthophoria or relief from diplopia, leading to satisfactory results. Postoperative drift may occur in exotropia. Case selection and preoperative counseling are necessary for cooperation during surgery, under topical anesthesia.

Anaesthetic considerations for strabismus surgery in children and adults

Strabismus correction surgery is the most common eye operation in children. Adults have approximately a 4% lifetime risk of developing strabismus. Current treatment options include pharmacological injection of botulinum toxin or bupivacaine, conventional corrective surgery, adjustable suture surgery and minimally invasive surgery. Repeated surgery is common as each operation has a 60%-80% chance of successful correction. The benefits of early surgical correction in large-angle strabismus in children outweigh the risks of anaesthesia. General anaesthesia is suitable for patients of all age groups, for complicated or repeated surgery, and bilateral eye procedures. Regional ophthalmic block reduces the incidence of oculocardiac reflex and emergence agitation, and provides postoperative analgesia, but requires a cooperative patient as many experience discomfort. Topical anaesthesia has been used in pharmacological injection, minimally invasive surgery, uncomplicated conventional strabismus surgery and some adjustable suture strabismus surgery. Its use, however, is only limited to cooperative adult patients. Prophylactic antiemesis with both ondansetron and dexamethasone is recommended, especially for children. A multimodal analgesia approach, including paracetamol, intravenous non-steroidal anti-inflammatory drugs, topical local anaesthetic and minimal opioid usage, is recommended for postoperative analgesia, while a supplementary regional ophthalmic block is at the discretion of the team.

Adjustable Strabismus Surgery under Topical Anesthesia: Alignment in Supine vs Seated Position

PURPOSE

To compare ocular deviation in the operating room depending on whether the patient is in supine decubitus or seated after single-stage adjustable strabismus surgery under topical anesthesia.

MATERIAL AND METHOD

We performed a prospective observational study of 30 patients with horizontal and/or vertical strabismus who underwent single stage adjustable strabismus surgery under topical anesthesia. Both distance and near deviation were evaluated before surgery, during surgery in both positions (seated and supine), and at 1 day, 1 month, and 3 months after surgery. A final horizontal deviation <10 pd and a vertical deviation <5 pd without diplopia was considered to be a good outcome (3 months after surgery).

RESULTS

The mean age of the sample was 55 years and 76.7% were women. Most had esotropia (70%). The most frequently used surgical combination was the medial rectus and lateral rectus (36.7%). Surgical adjustment was necessary in 40% of cases. Mean preoperative deviation was 21.9 ± 12.63 pd (distance) and 20.66 ± 4.76 (near). Deviation with the patient supine was 8 ± 8.25 pd (distance) and 7.26 ± 5.81 (near). Deviation with the patient seated was 8.13 pd±8.38 (distance) and 8.5 ± 7.41 (near). There was no significant difference between the positions. Outcome was favorable in 70% of patients; this percentage increased to 83.33% at 1 day, 1 month, and 3 months after surgery.

CONCLUSIONS

No statistically significant differences were found between ocular deviations in the seated or supine position in the operating room. Outcome was favorable in most cases 3 months after surgery. Intraoperative ocular deviation was not a predictor of outcome.

Remifentanil: A help in topical strabismus surgery

OBJECTIVE

To analyze the analgesic effect of remifentanil, side effects and complications in topical strabismus surgery. To study the results of strabismus surgery with this type of anesthesia.

MATERIAL AND METHOD

Retrospective descriptive study. We included 39 patients undergoing strabismus surgery with topical anesthesia and analgesia-based sedation with remifentanil. The data of the anesthetic and surgical technique, surgical results and stability of the deviation angle were analyzed.

RESULTS

Thirty nine patients (54% women) were included, the average age was 37,4years old. The mean follow-up was 24,5months. The preoperative diagnoses were exotropia (21 patients), esotropia (12), paresis strabismus (4) and Duane's Syndrome (2). 15% patients had preoperative diplopia and 13 had received previous treatments. The dose range of remifentanil used was 0.05 to 0.2μg/kg/min. The side effects presented were 2 cases of vomit and one of bad collaboration during the intraoperative adjustment, one of the patient reported pain and one case of thoracic rigidity was reported. 79% of the patients obtained a good surgical result and 82% reported being satisfied with the results. The reintervention rate was 5%.

CONCLUSIONS

Analgesia-based sedation with remifentanil is an useful complement to topical strabismus surgery because it reduces pain during surgery and allows the patient to collaborate during intraoperative adjustment due to its pharmacokinetic characteristics.

Comparison of topical oxybuprocaine and intravenous fentanyl in pediatric strabismus surgery

PURPOSE

To compare the outcomes such as postoperative nausea/vomiting, analgesic requirements, and hospital stay following the use of topical oxybuprocaine hydrochloride 0.4% or intravenous (IV) fentanyl in children undergoing strabismus surgery.

METHODS

This was a prospective cohort study. Children operated under general anesthesia for strabismus were given topical oxybuprocaine hydrochloride 0.4% (Group T) and IV fentanyl (Group F) before surgery. The episodes of nausea/vomiting, pain score, requirement of additional analgesia during postoperative period, and duration of hospital stay were compared in two groups.

RESULTS

There were 47 children in Group T and 59 children in Group F. The median pain score in two groups were 2.38 (25% quartile; 2.0) and 3.00 (25% quartile; 3.00), respectively. The difference was significant (K W P < 0.03). The episodes of nausea/vomiting in two groups were in 2 and 6 children in Group T and Group F, respectively. The median hospital stay of children of Group T and Group F were 242 and 285 min, respectively. The difference was not statistically significant (P = 0.22).

CONCLUSIONS

Using intraoperative topical oxybuprocaine drops, one can achieve better analgesic outcomes and reduce risk of nausea and vomiting compared to intravenous opioid analgesics and therefore, the hospital stay could also be marginally reduced.

Contact topical anesthesia versus general anaesthesia in strabismus surgery

OBJECTIVE

To evaluate the anesthetic block provided by contact topical anesthesia (CTA) in strabismus surgery in adult patients. To analyze postoperative pain and surgical outcome obtained by CTA compared with general anesthesia (GA).

METHODOLOGY

Prospective longitudinal cohort study of adult patients undergoing strabismus surgery by CTA or GA. The intensity of pain perceived by patients during the course of surgery and in the postoperative period was measured using Numerical Pain Scale. The success of the surgical outcome, considered as a residual ocular deviation<10 prism diopters, was evaluated.

RESULTS

Twenty-three patients were operated using CTA and 26 using AG. During the course of surgery, pain intensity experienced by patients in ATC group was 3.17±2.44. There were no differences between CTA group and AG group in the intensity of pain in the immediate postoperative period (2.13±2.39 vs. 2.77±2.18, respectively; P=.510) and during the first postoperative day (3.22±2.84 vs. 3.17±2.73; P=.923). Surgical success was significantly higher in the CTA group than in the GA group (78.3 vs. 73.1%; P=.019).

CONCLUSIONS

CTA provides adequate sensory block to perform strabismus surgery. The control of postoperative pain is similar to that obtained with AG. Conservation of ocular motility providing CTA enables better surgical outcome.

Contact topical anesthesia for strabismus surgery in adult patients

OBJECTIVE

To analyze the effectiveness and usefulness of contact topical anesthesia in strabismus surgery in adult patients.

MATERIAL AND METHODS

A prospective study was conducted on 20 patients undergoing strabismus surgery using contact topical anesthesia and sedation with remifentanil. The intensity of pain was recorded using a numeric pain rating scale at the time of anesthesia implementation, during the surgical procedure, 30 min afterwards, and during the first postoperative day. The incidence of oculocardiac reflex, postoperative nausea and vomiting, corneal ulcers, patient satisfaction (numerically from 0 to 10) and the degree of residual ocular deviation were also assessed.

RESULTS

The operation was performed successfully in all patients. Average pain intensity was 1.40 ± 1.73 during anesthesia implementation, 4.20 ± 2.57 during the surgical procedure, 2.50 ± 2.54 30 min after surgery, and 3.55 ± 2.89 during the first postoperative day. Oculocardiac reflex was observed in 7 patients (35%), postoperative nausea and vomiting in 4 (20%), and corneal ulcer in 4 (20%). The patient satisfaction was 9.53 ± 2.51. More than two-thirds (70%) of patients had a residual ocular deviation less than 10 prism diopters.

CONCLUSIONS

Contact topical anesthesia is a safe and effective alternative for strabismus surgery in adult patients. Contact topical anesthesia provides adequate pain control, lower incidence of postoperative nausea and vomiting and oculocardiac reflex, and optimal setting of ocular alignment.

[Methods of anesthesia in eye surgery]

There are several methods for local and general anesthesia in ophthalmological surgery that attempt to provide a stress and pain-free operating environment for both patient and surgeon. The decision-making depends on medical as well as on ophthalmological criteria and jointly falls to ophthalmologists and anesthesiologists. Topical and injective anesthesia (with or without conscious sedation) are generally methods of choice but general anesthesia can be preferable or mandatory in patients with particular internal diseases, children, emergencies and for extended surgical procedures. Pre-emptive analgesia before the operation is a meaningful complement in ophthalmological anesthesia.

Mini-plication to treat small-angle strabismus: A minimally invasive procedure

BACKGROUND

Mini-plication is a new rectus muscle tightening procedure for the correction of small-angle strabismus that can be performed under topical anesthesia. The purpose of this study was to report the outcomes of mini-rectus muscle plication.

METHODS

We retrospectively reviewed the medical records of patients who underwent mini-plication. In this procedure, 6-0 polyglactin 910 suture was secured to the central 3 to 4 mm of the muscle belly 5 mm posterior to the insertion and was then passed through the sclera just anterior to the muscle insertion to plicate the central portion of the muscle. This differs from the standard procedure, in which the entire width of the muscle is plicated. Two groups were analyzed: those who underwent mini-plication alone and those who underwent mini-plication after prior antagonist muscle-weakening surgery.

RESULTS

Our review identified nine patients aged 5 to 78 years. Topical anesthesia was used for all adults, who experienced no local or systemic complications. Mini-plication reduced vertical and horizontal deviations an average (± SD) of 6.7(Δ) ± 3.5(Δ). The mini-plication-only group (3 patients) had an average postoperative correction of 5.5(Δ) ± 2.6(Δ); the prior surgery group (6 patients), an average of 9(Δ) ± 2.7(Δ). Diplopia was noted in 50% of the adults preoperatively and none postoperatively. All patients experienced a decrease in strabismus, with an average outcome of <5(Δ) of postoperative deviation.

CONCLUSIONS

Mini-plication, which can be performed under topical anesthesia, corrected small deviations and was especially useful for adult strabismus patients with diplopia.

Adjustment in patients with asystole during strabismus surgery

PURPOSE

To investigate whether patients who developed asystole during strabismus surgery under general anesthesia also develop asystole during adjustment, and whether adjustment can safely be performed under topical anesthesia in these patients.

DESIGN

Retrospective, noncomparative interventional case series.

METHODS

Adjustment was performed with topical anesthesia in four patients aged 28, 32, 50, and 53 years who exhibited asystole during strabismus surgery under general anesthesia. Blood pressure and electrocardiogram were monitored during the adjustment.

RESULTS

Adjustment was successfully completed in all patients without asystole. Two patients showed oculocardiac reflex (OCR), with a reduction in heart rate (HR) >20% of the baseline value. One of these patients exhibited severe OCR that developed when the patient's posture was changed from the supine to the sitting position for measurement of the angle of strabismus after adjustment, and again during conjunctival manipulation after conjunctival closure. No patient required atropine.

CONCLUSIONS

Adjustment can safely be performed under topical anesthesia in patients who developed asystole during strabismus surgery under general anesthesia.

The efficacy of intravenous ketorolac for pain relief in single-stage adjustable strabismus surgery: a prospective, randomized, placebo-controlled trial

PURPOSE

To determine the efficacy of preoperative intravenous ketorolac in reducing intraoperative and postoperative pain and improving patient satisfaction in patients undergoing single-stage adjustable strabismus surgery.

METHODS

A prospective, randomized, placebo-controlled clinical trial was performed with 67 patients who underwent horizontal recti muscle surgery with adjustable sutures. The test group received intravenous ketorolac (60 mg) before surgery, and the control group received intravenous normal saline. Topical 0.5% proparacaine was administered to both groups during surgery. Vital signs including heart rate and blood pressure were recorded every 10 min throughout the surgery. The patients were asked to rate their maximum intraoperative and postoperative pain scores using a numerical pain rating scale. Patient satisfaction was also assessed using a five-point analogue scale.

RESULTS

The ketorolac-premedicated patients had less pain both during and after surgery (P = 0.033 and P = 0.024, respectively). There were no differences in vital signs during surgery and patient satisfaction between the two groups.

CONCLUSIONS

Intravenous ketorolac, when administered preoperatively for single-stage adjustable strabismus surgery under topical anaesthesia, was effective in reducing pain during and after surgery.

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.