Strabismus surgery under augmented topical anesthesia

Phased strabismus surgery under topical anesthesia

PURPOSE

To evaluate the feasibility and outcomes of phased strabismus surgery under topical anesthesia, with intraoperative comparison of ocular alignment in supine and seated positions.

METHODS

This retrospective clinical investigation analyzed the data of patients who underwent phased strabismus surgery with fixed sutures under topical anesthesia. The technique consisted of 2 phases, spaced out with an intraoperative alternate prism cover test (performed in supine and seated positions): (1) surgery on one or two muscles, as defined by a preoperative surgical plan; (2) if judged necessary, a further one-muscle surgery. Surgical success was defined as a residual angle of horizontal and vertical deviation ≤±8Δ and ≤5Δ, respectively, and the presence of single binocular vision in primary position in patients with preoperative diplopia. Follow-up visits were scheduled 1 day, 1 month, and 6 months after surgery.

RESULTS

The review identified 38 patients (age range: 10-80 years). Surgery was well tolerated by all patients. Twelve (32%) required a second phase. No statistically significant differences were found for intraoperative angles of deviation in supine and seated positions. Surgical success was reached, respectively, in 88% and 87% of cases with horizontal and vertical deviation 6 months after surgery. No patients were reoperated during the follow-up period.

CONCLUSIONS

Phased strabismus surgery is a feasible technique for various types of strabismus in adults and children. Secondly, intraoperative evaluation of ocular alignment can be performed either with the patient seated or supine, with the same accuracy in terms of surgical success.

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.

Anaesthesia for ophthalmic procedures in patients with thyroid eye disease

Thyroid eye disease is an autoimmune inflammatory disorder of the orbit in adults. It causes inflammation, expansion and fibrosis of orbital fat, muscles and the lacrimal gland, leading to facial disfigurement, functional disability and, in severe cases, blindness. Overall, approximately 20% of affected patients need some form of surgical intervention requiring anaesthesia. This narrative review explores the background of thyroid eye disease, surgical procedures performed and their implications for anaesthesia. General anaesthesia is used for orbital decompression procedures, strabismus correction surgery and complex oculoplastic procedures. Local anaesthetic infiltration or regional anaesthesia under monitored anaesthesia care are the techniques most commonly employed for eyelid retraction surgery. It is important to limit the volume of local anaesthetic agent used during infiltration and continuously monitor the orbital volume and ocular pressure with a ballottement technique. In addition, the contralateral eye should be checked and, if necessary, protected against corneal exposure. Retrobulbar, peribulbar and sub-Tenon's blocks are best avoided. Topical anaesthesia has been used for some strabismus correction surgery but its use is limited to motivated and cooperative patients only.

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.

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.

A randomised comparison of lidocaine 2% gel and proparacaine 0.5% eye drops in paediatric squint surgery

We conducted a randomised trial comparing lidocaine 2% gel with proparacaine 0.5% eye drops in children having elective squint surgery. One hundred and forty children aged between 3 and 14 years were recruited. The requirement for intra-operative fentanyl and postoperative ibuprofen was significantly less in the lidocaine group compared with the proparacaine group (1 (1.7%) vs 12 (18.5%), p=0.002 and 16 (27.6%) 38 (58.5%), p=0.001, respectively). The incidence of postoperative nausea and vomiting was significantly less in the lidocaine group compared with the proparacaine group (6 (10.3%) vs 16 (24.6%), p=0.04). There were no differences between the groups in terms of incidence and severity of the oculocardiac reflex. We conclude that, compared with proparacaine 0.5% eye drops, a single application of lidocaine 2% gel improves peri-operative analgesia and reduces the incidence of postoperative nausea and vomiting in elective paediatric squint surgery.

Adjustable suture strabismus surgery

Surgical management of strabismus remains a challenge because surgical success rates, short-term and long-term, are not ideal. Adjustable suture strabismus surgery has been available for decades as a tool to potentially enhance the surgical outcomes. Intellectually, it seems logical that having a second chance to improve the outcome of a strabismus procedure should increase the overall success rate and reduce the reoperation rate. Yet, adjustable suture surgery has not gained universal acceptance, partly because Level 1 evidence of its advantages is lacking, and partly because the learning curve for accurate decision making during suture adjustment may span a decade or more. In this review we describe the indications, techniques, and published results of adjustable suture surgery. We will discuss the option of 'no adjustment' in cases with satisfactory alignment with emphasis on recent advances allowing for delayed adjustment. The use of adjustable sutures in special circumstances will also be reviewed. Consistently improved outcomes in the adjustable arm of nearly all retrospective studies support the advantage of the adjustable option, and strabismus surgeons are advised to become facile in the application of this approach.

Practical aspects and efficacy of intraoperative adjustment in concomitant horizontal strabismus surgery

PURPOSE

To analyze the practical aspects and advantages of one-stage adjustable surgery under topical anesthesia in concomitant horizontal strabismus.

METHODS

A retrospective review of 363 patients was completed to assess (1) the frequency of need to perform adjustment, (2) the amount and pattern of adjustment, and (3) the final alignment at least 6 months after surgery. Intraoperative adjustment was performed strictly toward the aim of orthophoria or slight overcorrection (heterophoria < 6 prism diopters [PD]) while avoiding diplopia.

RESULTS

Of the 363 patients, 261 (72%) required intraoperative adjustment. Of these, 85% of exotropes underwent a decreased amount of surgery compared with the standard amount, whereas 58% of esotropes underwent an increased amount of surgery. Forty-two patients underwent a one-muscle surgery instead of the scheduled two-muscle surgery, and all had less than 35 PD preoperative angle of deviation. Success rates were 83% in all patients with one-stage adjustable sutures and 87% in patients who underwent adjustment. In 42 patients with one-muscle surgery instead of two-muscle surgery, 32 (76%) obtained successful results.

CONCLUSION

Intraoperative adjustment was effective in concomitant horizontal strabismus surgery and can provide the opportunity to avoid a large overcorrection, especially in cases with moderate angle horizontal muscle surgery.

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.

Topical anesthesia in strabismus surgery: a review of 101 cases

PURPOSE

To analyze the results over a 10-year period with a different type of strabismus surgery performed with topical anesthesia, to describe the differences in technique compared with surgery performed with general anesthesia, and to detail current indications and technical changes made according to the experience accrued during these years.

METHODS

A total of 101 patients undergoing strabismus surgery with topical anesthesia in a single hospital were analyzed. These patients were randomly selected from a total of 567 patients who had undergone extra-ocular muscle surgery in the past 10 years.

RESULTS

A good result was obtained (squint angle < 10 prism diopters and absence of diplopia) in 95% of patients immediately after surgery and in 85% at final follow-up (mean follow-up: 3.1 years). The mean operating time for each muscle was 29 minutes. Surgery was well tolerated in every patient. Conversion to general anesthesia was not necessary in any case. Atropine was used in three patients (3%) because of induction of the vagal reflex.

CONCLUSION

Topical anesthesia in strabismus surgery is a useful technique in the treatment of extraocular muscle pathology, with few limitations. Appropriate monitoring by an anesthetist is vital to ensure adequate control of pain and possible side effects and to enable conversion to general anesthesia. The oculocardiac reflex is infrequent. For experienced strabismus surgeons, the total surgical time is comparable with topical and general anesthesia.

Persistence of eye movement following disinsertion of extraocular muscle

BACKGROUND

It is widely assumed that the insertion of the extraocular muscle is the sole site of force translation from muscle to eye. Our aim was to test this assumption by examining ocular motility after disinsertion of the extraocular muscle.

METHODS

Forty-two adults (age, 20-45 years; median age, 26 years) underwent strabismus surgery. All surgeries were completed under topical anesthesia with lidocaine 2% jelly or peribulbar sensorimotor differential blocking anesthesia with ropivacaine 0.2%. Sixty-six rectus muscles and six oblique muscles were suture-locked and disinserted. After disinsertion of each muscle, the patient was asked to move the eye in the field of action of the muscle; eye movement was recorded as normal, reduced, or absent.

RESULTS

For 50 rectus muscles (76%), eye movement was normal after disinsertion, while for 14 rectus muscles (21%), eye movement was reduced after disinsertion. For only two rectus muscles (3%), eye movement was absent after disinsertion. For all six oblique muscles (100%), eye movement was normal after disinsertion.

CONCLUSIONS

The unexpected, strong persistence of eye movement in the direction of action of the disinserted muscle indicates that anatomic insertion not only occurs at the point at which the muscle blends into the sclera but also involves the surrounding connective tissue. Orbital connective tissue can be considered an additional and important locomotor system.

The Eye Sensation Scale: an ophthalmic pain severity measure

PURPOSE

The aim was to develop a single-item, categorical ophthalmic pain severity scale.

METHODS

Focus groups were held with people who had experienced ophthalmic pain. Participants described their ophthalmic pain experiences with reference to level of severity, and commented on proposed pain scale designs. Thematic analysis of transcripts, and participants' category choices and scale preferences, were used to determine the number of response categories and labels chosen for the instrument. The final instrument was evaluated using a mail-out questionnaire.

RESULTS

Five ophthalmic pain domains were identified: intensity; nature (including subdomains: physical sensation, temporal patterning, simile/metaphor); physical effects; emotional effects; and behavioral effects. The most frequent descriptors were physical sensation (n = 160), behavioral effects (n = 87), and physical effects (n = 68). Participants preferred a five-category scale. The higher frequency severity descriptors used by the participants formed the basis for the category labels for the instrument ("extreme," "severe," "moderate," "mild," "none"). Notably, many participants rejected the word "pain" in favor of "discomfort" or "light sensitivity." Participants commonly linked severity and nature descriptors; however, the same nature descriptor (e.g., "ache" or "scratching") did not confer the same pain severity between participants.

CONCLUSIONS

A five-category scale was chosen for assessing the severity of ophthalmic sensations: the Eye Sensation Scale. The scale involves rating the severity of the ophthalmic sensation that is most important to the patient and provides the opportunity to describe other attributes or effects of the sensation. Evaluation indicated the adequacy of the final instrument.