The use of propofol and mivacurium anesthetic technique for the immediate postoperative adjustment of sutures in strabismus surgery

Stepped Strabismus Surgery

Purpose

To present stepped strabismus surgery as a novel technique in cases of small to moderate angle strabismus.

Methods

Retrospective chart review of cases of stepped strabismus surgery from 2010 untill 2018. In stepped surgery, the first muscle is operated on under rapid induction-recovery IV propofol infusion. Patient is assessed in the OR. If deemed necessary, other muscles are operated on under general anesthesia. No adjustable sutures are used.

Results

The technique was used in 22 cases of superior oblique palsy (SOP) (primary position hypertropia in the range of 12–25 prism diopters) and 29 horizontal strabismus cases (angles in the range 12–20 prism diopters). The first step was an inferior oblique myectomy in the SOP cases and a single rectus recession in the horizontal cases. After intraoperative assessment, 31% (16/51) needed additional muscle surgery. After 6 months of follow up, the overall reoperation rate was 9%. The technique was well tolerated by all patients.

Conclusion

Stepped strabismus surgery is a useful technique for small to moderate angle strabismus cases with the potential for reducing the number of extraocular muscles operated on without compromising the surgical outcome.

Peribulbar anesthesia for strabismus surgery in adult patients

PURPOSE

To evaluate the efficacy and safety of peribulbar anesthesia during strabismus surgery.

METHODS

Medical records of patients undergoing strabismus surgery and peribulbar anesthesia were reviewed. The overall efficacy of peribulbar anesthesia was evaluated as requirement of supplemental peribulbar anesthesia, impossibility to perform eye muscles surgery due to inadequate efficacy of the block and peribulbar block complications that occurred up to 6 weeks postoperatively. Presence of oculocardiac reflex (OCR) and presence of decreased visual acuity and afferent pupillary defect postoperatively were reported.

RESULTS

A total of 510 patients comprised our study group. The total amount of peribulbar injections was 717. Four patients (0.7%) required supplemental injection in the superonasal quadrant. Five of 510 (0.9%) required an anesthesiologic intervention with intravenous atropine. Eighty patients of 510 (15.6%) complained about transitory complete ptosis and/or amaurosis postoperatively. No complications were observed up to 6 weeks postoperatively.

CONCLUSION

Peribulbar anesthesia was an effective and safe option during strabismus surgery in adult patients.

Selection of patients and results of 25 years of topical anesthesia and adjustable suture surgery

BACKGROUND AND PURPOSE

The author has used adjustable suture techniques either in the operating room with topical anesthesia or at a later time after retrobulbar or general anesthesia for over 25 years. Careful selection of patients is essential to the success of this technique. It is the purpose of this paper to report the selection criteria used and to compare the results of the two methods utilized.

PATIENTS AND METHODS

One hundred eighty-three patients were included in this study: 123 were operated upon with topical anesthesia. For comparison, sixty patients were included who had adjustment later in the day or the next day after having retrobulbar or general anesthesia. Both horizontal and vertical strabismus cases were included.

RESULTS

Adjustable techniques done in the operating room or at a later time have both shown significant improvement in the strabismus angle following one operation in 86% of the cases. Diplopia was eliminated in 63% of patients with this complaint. (63% and 64.5% in the two groups, respectively). Seventeen of 123 patients having topical anesthesia (13.8%) required a second operation, and 8 of 60 (13.3%) of those having a later adjustment needed further surgery.

CONCLUSION

Careful selection of patients undergoing strabismus surgery allows successful topical muscle adjustment in the operating room with results similar to adjustments done following retrobulbar or general anesthesia at a later time.

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.

Effect of slow-releasing all-trans-retinoic acid in bioabsorbable polymer on delayed adjustable strabismus surgery in a rabbit model

PURPOSE

To determine the usefulness of slow-releasing all-trans-retinoic acid (ATRA) in polytetrafluoroethylene (PTFE)/polylactide-co-glycolide (PLGA) for delayed adjustable strabismus surgery.

DESIGN

Animal study.

METHODS

A prospective, masked-observer, controlled study was performed in 25 rabbits. Fifty rabbit eyes were divided randomly into three groups. After a recession of the superior rectus muscle, a PTFE/PLGA laminate containing ATRA, PTFE alone, or balanced salt solution was applied beneath and over the superior rectus muscle in the PTFE/PLGA/all-trans-retinoic acid group (ATRA group), the polytetrafluoroethylene group (PTFE group), and the control group, respectively. Delayed adjustment was performed once on each superior rectus muscle at 3 or 5 weeks after surgery by a masked observer.

RESULTS

In the control group, adjustment was possible in 2 of 5 eyes at 3 weeks after surgery and impossible in any eye at 5 weeks after surgery. In the PTFE and ATRA groups, adjustment was possible in all 10 eyes at 3 and 5 weeks after surgery. On comparing adjustability, a significant difference was observed between the PTFE group and the control group or between the ATRA group and the control group 5 weeks after surgery (P = .0003 and P = .0003, respectively). A significant difference was observed between the ATRA group and the control group in terms of adhesion between superior rectus muscles and sclerae at 5 weeks after surgery (P = .006).

CONCLUSIONS

Slow-releasing ATRA in PTFE/PLGA was found to reduce adhesion and to allow delayed adjustment in most eyes for up to 5 weeks after surgery.

Propofol–remifentanil-based anaesthesia vs. sevoflurane–fentanyl-based anaesthesia for immediate postoperative ophthalmic evaluation following strabismus surgery

BACKGROUND AND OBJECTIVE

Following strabismus surgery, immediate postoperative ophthalmic evaluation may be desired. Thus, an anaesthetic technique allowing rapid recovery of ocular motility is required. Saccadic eye movements is a biophysical monitor of ocular motility and may be used to assess recovery from anaesthesia. The aim of this study is to compare the time to the recovery of saccadic eye movements in patients, following one of two anaesthetic techniques: Propofol-remifentanil-based anaesthesia vs. sevoflurane-fentanyl-based anaesthesia.

METHODS

Fifty adult patients undergoing strabismus surgery were randomly assigned to one of two groups: patients in Group R received induction and maintenance of anaesthesia with propofol and remifentanil, while patients in Group S received induction of anaesthesia with propofol and fentanyl and maintenance of anaesthesia with sevoflurane. Recovery from anaesthesia was measured from the time all anaesthetics were turned off and was assessed every 2 min. Recovery time was attained when patients were able to generate brisk saccadic eye movements. At recovery time, the ophthalmic evaluation was started.

RESULTS

The mean recovery time of saccadic eye movements was significantly shorter in the Group R when compared to the Group S (12.1 +/- 4.3 min vs. 21.5 +/- 4.7 min, respectively, P < 0.0001). More patients in Group S experienced nausea and vomiting postoperatively as compared to Group R (9/25 vs. 2/25, respectively, P = 0.037).

CONCLUSIONS

Propofol-remifentanil-based anaesthesia may be a useful technique in strabismus surgery when immediate postoperative ophthalmic evaluation is desired. When compared to sevoflurane maintenance of anaesthesia, it allows for a more rapid recovery from anaesthesia as judged by recovery of saccadic eye movements and a decreased incidence of postoperative nausea and vomiting.

Combined propofol sedation with sub-Tenon's lidocaine/mercaine infusion for strabismus surgery in adults

AIMS

To evaluate the safety and efficacy of propofol sedation combined with sub-Tenon's anaesthesia for strabismus surgery in adults.

METHODS

Thirty-two consecutive patients aged 31-85 years underwent strabismus surgery under general (n=16) or local (n=16) anaesthesia. In the local anaesthesia (study) group, sedation was induced with a loading dose of midazolam, fentanyl, and propofol, followed by continuous infusion of propofol, 3-6 mg/k/h to deep sedation. A nasal tube was inserted to prevent airway obstruction. Sub-Tenon's anaesthesia included infusion of a 3-4 ml mixture (50 : 50) of lidocaine 2%/mercaine 0.5%. General anaesthesia consisted of premedication with midazolam, followed by fentanyl, esmeron-bromate, propofol, and tracheal intubation. Duration of surgery and anaesthesia, intraoperative oculocardiac reflex and arrhythmias, time to discharge, postoperative pain, nausea and vomiting, and patient and surgeon satisfaction were evaluated.

RESULTS

The local anaesthesia group had a significantly shorter operative and anaesthesia time, fewer episodes of oculocardiac reflex or arrythmia/bradycardia requiring treatment, fewer early or late episodes of nausea and vomiting, and less pain. The patients and surgeon in this group reported higher satisfaction.

CONCLUSION

Propofol sedation with local sub-Tenon's injection of lidocaine/mercaine is recommended for the induction and maintenance of anaesthesia during unilateral or bilateral strabismus surgery in adults. The method is quick and effective, without systemic or ocular side effects.

Comparison of the immediate with the 24-hour postoperative prism and cover measurements in adjustable muscle surgery: is immediate postoperative adjustment reliable?

PURPOSE

Immediate postoperative adjustment after adjustable-suture strabismus surgery has been suggested as a viable alternative to the classic adjustment that is performed, usually within 6 to 24 hours after surgery. The purpose of this study was to compare the immediate postoperative eye measurements with those taken 24 hours postoperatively and to determine whether there was any significant difference between the 2 measurements.

METHODS

This was a prospective study of strabismus patients who were candidates for muscle surgery using the adjustable-suture technique. All patients received a total intravenous general anesthesia, which allowed rapid recovery of consciousness. Measurements using the simultaneous prism cover test were obtained in the recovery room immediately after the patients regained consciousness and again 24 hours after surgery. Both measurements were taken before adjustment and were compared.

RESULTS

A total of 25 patients were studied. The postoperative alignment changed significantly during the first 24 hours in 84% of our patients. The mean drift in alignment during the first 24 hours measured 7.2 +/- 4.3 prism diopters and was significantly different from 0 ( P < 0.001).

CONCLUSION

The immediate postoperative ocular alignment after adjustable strabismus surgery is significantly different from the 24 hours postoperative alignment. This difference was noticed despite using an anesthesia protocol that allowed rapid recovery and full regaining of consciousness shortly after the conclusion of surgery. This early drift should be taken into consideration if adjustment is to be made in the immediate postoperative period.

Adjustable sutures in children using a modified technique

PURPOSE

Adjustable-suture techniques are commonly used to decrease the reoperation rate in adults undergoing strabismus surgery, but they are infrequently used in children because of the difficulty of performing adjustments on a conscious child. The purpose of this study is to evaluate a new technique for using adjustable sutures in children, which makes the second stage of the procedure unnecessary if no adjustment is needed.

METHODS

This was a retrospective study of children who underwent surgery for exotropia or esotropia. The technique used was a variation of the standard fornix-based adjustable suture with a separate slipknot. The pole sutures were buried within the sclera and tied; then the incision of the conjunctiva was closed to cover the adjustable sutures. The patients were then measured 4 to 6 hours after the initial surgery. The decision of whether to adjust was based on predetermined criteria. Those children not adjusted were discharged with no further manipulation needed because the conjunctiva was already closed. For those children who were adjusted, the adjustment was made with the patient under intravenous propofol sedation or laryngeal mask anesthesia.

RESULTS

A total of 61 consecutive children ages 12 months to 14 years underwent surgery using this technique. Patients were followed-up after surgery for a minimum of 6 weeks (median 19.4). Fifty-four of the 61 patients (88%) were within 10 prism diopters (PD) of orthophoria on their final postoperative visit. Of the 22 patients who underwent an adjustment, 20 (91%) were within 10 PD of orthophoria at their final postoperative visit. The median follow-up was 19.4 weeks (range 6 to 45.9).

CONCLUSIONS

This new adjustable-suture technique was associated with excellent short-term eye alignment. It is particularly suited for pediatric surgery because it eliminates the necessity of further manipulation of children who do not require adjustment.

The immediate postoperative adjustment of sutures in strabismus surgery with comaintenance of anesthesia using propofol and midazolam

PURPOSE

Adjustable suture techniques are used to reduce the reoperation rate in strabismus surgery, but traditionally require that final adjustments be made between 1 to 24 hours after surgery. The purpose of this study was to evaluate a new anesthetic technique that would allow immediate postoperative adjustment of sutures in strabismus surgery, thereby improving patient convenience and comfort.

METHODS

This was a prospective study of strabismus patients who were judged to be appropriate candidates for adjustable sutures. Comaintenance of anesthesia was accomplished using a stepped-down infusion of propofol with midazolam. Final suture adjustments were performed in the operating room immediately upon completion of strabismus surgery. Patient satisfaction was assessed 24 hours later. Patients were followed for 6 weeks postoperatively.

RESULTS

A total of 16 patients were studied, with 8 patients having horizontal muscle surgery, 7 patients with vertical muscle surgery, and 1 patient undergoing both horizontal and vertical muscle surgery. The change in deviation after 6 weeks of follow-up was 8 PD or less horizontally in all patients and 4 PD or less vertically in 87% of patients when compared with the alignment in the operating room. Diplopia, if present, resolved in 85% of patients. One patient (6.7%) required a second surgery. The mean drift at 2 weeks horizontally was 1.87 PD esotropic (range, -6 PD exophoric to 18 PD esotropic) and vertically 0.94 PD (range, -4 PD hypotropic to 4 PD hypertropic). The mean drift at 6 weeks horizontally was -0.27 PD exotropic (range, -8 PD exophoric to 8 PD esotropic) and vertically 0.6 PD (range, -6 PD hypotropic to 10 PD hypertropic).

CONCLUSION

The immediate postoperative adjustment of sutures in strabismus surgery may be accurately performed using this new anesthetic technique.

Timing of postoperative adjustment in adjustable suture strabismus surgery

PURPOSE

The use of adjustable sutures in strabismus surgery has increased the rate of surgical success. Little data are available on the optimum timing for postoperative adjustment after strabismus surgery. We wanted to compare 2 common practices of adjustable suture technique after strabismus surgery.

METHODS

Two comparable groups of 40 patients each, who had strabismus surgery with adjustable suture technique, were prospectively studied. Group A had early adjustment the same day of the surgery about 6 hours after the operation, and group B had late adjustment the next day about 24 hours after the operation. Subjective scoring tables were used to evaluate the pain felt by the patient before, during, and after the adjustment and any difficulties of the adjustment process. Requirements of postoperative pain medications and final alignment 6 weeks after surgery were also compared.

RESULTS

Despite adequate statistical power, no significant differences were found between the groups regarding pain before, during, and after adjustment, difficulties performing the adjustment, and final alignment after 6 weeks (P > .05). Both adjustment schedules were equally associated with mild to moderate pain before, during, and after the adjustment. In the first 24 hours after surgery, no overall difference in the use of pain medications was found. Nausea and vomiting in the first 24 postoperative hours were more common in the early adjustment group (P = .02).

CONCLUSION

The surgeon can feel free to choose the timing for postoperative adjustment. However, when performing an early adjustment, the surgeon should be especially prepared to control nausea and vomiting.

The use of subtenon ropivacaine in managing strabismus with adjustable sutures

BACKGROUND

Squint angle alterations with the use of adjustable sutures after strabismus surgery can be painful. Ropivacaine is a long-acting local anesthetic that, at low doses, produces sensory block with limited nonprogressive motor block.

METHOD

We performed a double-blind, randomized, pilot study using subtenon ropivacaine or placebo at the time of surgery in patients undergoing adjustable suture surgery. Surgery was performed by the same surgeon in each case. Later in the day, the same surgeon adjusted the sutures. At the time of adjustment, the patient recorded pain using a linear pain score, and the surgeon recorded ease of adjustment using a linear score. The results of surgery were noted at 4 weeks.

RESULTS

Ten patients were randomized to receive ropivacaine and 11 to receive placebo. All 10 of the ropivacaine group and 9 of the placebo group had suture adjustment. In the ropivacaine group, there was a significantly lower pain score (P <.05, Mann-Whitney U test) but no significant difference in ease of adjustment. There appeared to be no demonstrable difference in the results of surgery between the 2 groups.

CONCLUSION

Ropivacaine appears to reduce the pain of postoperative suture adjustment without adversely affecting the final outcome, although it does not appear to ease the adjustment itself. This small pilot study shows promising results in postoperative analgesia in these patients, although further larger trials are recommended.

Adjustment of sutures 8 hours vs 24 hours after strabismus surgery

PURPOSE

To compare the postoperative results of adjustable-suture strabismus surgery when suture adjustment was performed 8 hours (group 1) and 24 hours (group 2) after surgery.

METHODS

A retrospective clinical study was conducted in two hospitals. Strabismus surgery and muscle adjustment were performed in 90 patients. All patients had horizontal strabismus (40 patients had esotropia and 50 patients had exotropia), and they underwent either primary surgery or reoperation. Mean age of the patients was 29.9 +/- 14.1 (range, 14 to 74) years. The angle of deviation was measured in all patients before surgery, after surgery both before and after adjustment, and at the final follow-up examination. The follow-up period was 6 to 40 months (mean, 19.6 months).

RESULTS

Preoperative data were similar in the two groups. The mean angle of deviation immediately after muscle adjustment was 0.6 +/- 6. 1 prism diopters in group 1 and 0.4 +/- 6.3 prism diopters in group 2. This similar deviation in the two groups (P =.9) changed during the follow-up period, and at the final examination the measured angles in groups 1 and 2 were -1.0 +/- 7.9 and -2.5 +/- 10.3 prism diopters, respectively (P =.48). The most considerable outcome measure was the calculated drift values. At the last follow-up these values were -1.6 +/- 5.8 for group 1 and -2.9 +/- 11 prism diopters for group 2 (P =.5). Subdividing the patients on the basis of their deviation before surgery, a postoperative drift toward exotropia was found in most patients of group 1. In group 2, however, a greater tendency toward exotropia was shown only by those patients who had displayed exotropia preoperatively, whereas patients with preoperative esotropia showed a greater tendency toward esotropia after surgery.

CONCLUSION

In patients undergoing horizontal extraocular muscle surgery with adjustable sutures, suture adjustment 8 hours or 24 hours after surgery did not produce significantly different results.

A comparison of sutures for adjustable strabismus surgery

BACKGROUND

The adjustable suture technique after strabismus surgery may be more easily performed if the sutures offered minimal resistance during the procedure as desired by the surgeon.

METHODS

In a rabbit model, 3 different types of 6-0 absorbable sutures-Biosorb-C (polyglycolic acid with polycaprolate coating, Alcon Surgical), coated Vicryl (polyglactin 910 coated with polyglactin 370 and calcium stearate, Ethicon), and Dexon-"S" (polyglycolic acid, Davis and Geck)-were advanced through scleral tunnels when attached and not attached to extraocular muscles. Resistance was measured with a precise strain gauge accurate to 0.1 g with an intrinsic microprocessor.

RESULTS

For unattached advancements, Biosorb-C offered significantly less resistance than Vicryl at 6 and 24 hours after operation (P < .02), whereas Dexon-"S" offered less resistance than Vicryl only at 24 hours (P = .001). At 6 hours, Biosorb-C sutures were marginally more slipperythan Dexon-"S" (P= .07). For sutures attached to extraocular muscles at 6 hours after surgery, the 3 sutures offered similar resistance. By 24 hours after the initial procedure, Vicryl presented significantly more resistance than either Biosorb-C or Dexon-"S" (P< .01 for both). For all comparisons of 6 versus 24 hours after surgery, the only significant increase in resistance were Vicryl sutures attached to muscles (P= .02).

CONCLUSIONS

These data support the use of Biosorb-C and Dexon-"S" for the adjustable suture technique whether adjusted at 6 or 24 hours after the initial procedure, although Biosorb-C may be slightly easier to adjust at 6 hours. If Vicryl is used, it would be easier to adjust the muscle 6 hours after surgery rather than after 24 hours.

Slipped and lost muscles and other tales of the unexpected. Philip Knapp Lecture

Loss of a rectus muscle may occur as a rare complication of strabismus surgery. In addition, extraocular muscles may become traumatically detached from the globe when they rupture or are transected as the result of an injury or during the course of retinal detachment or paranasal sinus or orbital surgery. Although the clinical features of a slipped muscle may resemble those of a lost muscle, the findings at the time of reoperation are distinct. Also the etiology, and therefore the prevention, of a slipped muscle differs from that of a lost muscle. It is likely that slipped muscles and even some lost muscles are underdiagnosed and represent a significant cause of unexpected overcorrection or undercorrection. Unless the displaced muscle is appropriately advanced, it can be extremely difficult to correct the associated strabismus, yet locating and repairing either a lost or slipped muscle can be challenging and is by no means always successful. Current concepts pertaining to the etiology, recognition, and management of slipped and lost muscles will be discussed.

Perianesthesia care of adult and pediatric strabismus surgery patients

Strabismus procedures on children and adults are frequently performed in an outpatient setting. Perianesthesia care of patients having strabismus procedures may be optimized by recognizing the characteristics of strabismus patients, the frequently associated diagnoses that may affect perioperative care, and the specific surgical techniques used to treat strabismus. Complications including postoperative nausea, pain, prolonged PACU stay, and unplanned postoperative admissions can be minimized and treatment facilitated by preparing patients with preoperative instructions, careful choice of anesthetic agents and postoperative medications, and appropriate perioperative care. This report will provide a brief review of surgical strabismus, including current techniques, and present guidelines for perioperative care of pediatric and adult strabismus patients.