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

Temporal Slant Recession of the Inferior Rectus Muscle: A Simple Surgical Treatment for Diplopia Caused by Small Vertical Deviations

BACKGROUND

To evaluate the therapeutic effect of temporal slant recession of the inferior rectus muscle (TSRIRM) for the treatment of small vertical deviations in patients with vertical diplopia, with consideration of the theoretical additive effects of this procedure on ocular torsion and horizontal incomitance.

METHODS

Retrospective review of 11 patients who were treated with TSRIRM. Eight patients with vertical diplopia and small hyperdeviations (up to 6 prism diopters (PDs)) were treated with isolated TSRIRMs. Three patients with vertical diplopia from unilateral superior oblique palsies with large hyperdeviations (>15 PDs) were treated with TSRIRMs in conjunction with contralateral inferior oblique recessions.

RESULTS

Six of the 8 patients with small vertical deviations had successful vertical realignment with elimination of symptomatic diplopia after an isolated TSRIRM. Two of the eight patients had residual hypertropia with symptomatic diplopia. Three additional patients with unilateral superior oblique palsy had successful vertical realignment with elimination of symptomatic diplopia after ipsilateral inferior oblique recession and contralateral TSRIRM. In total, 9 of 11 patients had successful surgical results after TSRIRM.

CONCLUSIONS

TSRIRM provides an effective and reliable treatment for small angle vertical strabismus. Its ease of surgical access renders it useful for implementation in an outpatient neuro-ophthalmology setting.

Convergence insufficiency with diplopia: Surgical treatment in adults

OBJECTIVE

To study the outcomes of treatment with central mini-plication of the medial rectus (MR) muscles in adult convergence insufficiency with diplopia.

METHODS

The study sample comprised 9 cases (7 women). The length of MR plication was collected. Other variables reported were postsurgical deviation, overcorrections in the early postoperative period and at the end of follow-up, final horizontal deviation at near and at distance vision, diplopia, and mean follow-up from surgery. Surgical outcome was considered to be favorable when diplopia and symptoms were resolved and final exotropia at near was ≤8 pd at the end of follow-up.

RESULTS

A central mini-plication of the MR was performed in 9 patients (8 unilateral). Mean (± SD) age was 58.66 (21.39) years. Mean near preoperative deviation: 16.22 (± 2.9) pd and distance preoperative deviation: 6.88 (± 4) pd Overcorrection at distance vision was recorded in 5 cases; this resolved by 3 months postoperatively. There was not overcorrection at near vision except one case. None of the cases operated on had overcorrection at the end of follow-up The final horizontal deviation was ≤8 pd at near vision, except for 3 cases (mean: 6.22). Symptoms and diplopia resolved in 8 cases. The mean follow-up was 10.33 months.

CONCLUSION

Central mini-plication of 1 or 2 medial rectus muscles can improve the symptoms and signs of exotropia associated with convergence insufficiency when exercises and the prisms are rejected by the patients and when these approaches have not solved the problem.

Strabismus Surgery in Orthophoric Patients With Symptomatic, Asymmetric Vertical or Horizontal Incomitance

PURPOSE

To report the indications, operative strategies, and surgical outcomes of patients who undergo vertical and horizontal rectus muscle surgery for incomitant strabismus despite being orthophoric in primary gaze.

DESIGN

Retrospective, interventional case series.

METHODS

The setting for this study was an academic practice at Boston Children's Hospital. The patient population comprised 8 orthophoric patients who underwent strabismus surgery to treat vertical/horizontal incomitance. Observation procedures included review of surgical strategies, strabismus measurements in diagnostic gaze positions, and development of postoperative diplopia. The main outcome measures were preserved single vision in primary gaze, comitance, reoperation rate, and patient/surgeon satisfaction.

RESULTS

Surgical strategies included the following: (1) simultaneous recession of ipsilateral antagonist rectus muscles; (2) recession or resection of 1 rectus muscle with balancing surgery on the fellow eye; (3) restricting the range of 1 muscle (combined resection and recession or posterior fixation suture); and (4) creating an acceptable deviation in primary gaze. Mean follow-up was 5.4 months (median, 2 months; range, 2-25 months). No patient had new-onset primary gaze diplopia. The median incomitance improved by 9.5 prism diopters. No patient required additional surgery. Patient satisfaction and surgeon assessment of outcomes were high.

CONCLUSIONS

Although the risk of operating on orthophoric patients with incomitant strabismus may discourage surgeons from offering treatment, the use of specific strategies to address incomitance can preserve alignment in primary gaze while improving patient satisfaction. These strategies may also benefit patients with incomitant strabismus that is symptomatic in primary gaze.

Inferior oblique recession associated to partial temporal inferior rectus recession in unilateral congenital superior oblique palsy

PURPOSE

To evaluate the effectiveness of inferior oblique recession with contralateral partial temporal inferior rectus recession in patients with decompensated congenital unilateral superior oblique palsy (SOP) in correcting moderate vertical deviations in primary position.

METHODS

The medical records of patients with SOP who underwent inferior oblique recession with contralateral partial temporal inferior rectus recession were reviewed retrospectively. Vertical deviation in primary position, subjective torsion, diplopia, residual deviation, and the deviation decrease were evaluated.

RESULTS

Four patients (three males and one female, age range 29-56 years) with congenital unilateral SOP and mean vertical deviation of 21.0 ± 5.3PD (range 14-25D) in primary position were included. Mean correction of hypertropia in primary position with this technique was 15.5 ± 5.3PD (range 10-20PD). The mean hypertropia on gaze to the contralateral side changed from 30.0 ± 10.8D before surgery to 9.3 ± 7.9D after surgery. Torsion had a mean change of 4.8° of incyclodeviation. Preoperatively, all patients had head tilt and diplopia, which was resolved in all but one patient, who will need surgery. Patients were followed an average of 18 months. No adverse events were reported in any subjects.

CONCLUSION

When performing recession of inferior oblique muscles in SOP associated to a full recession of the contralateral inferior rectus, there is a risk of overcorrection in those with moderate angles. Performing a partial recession in the contralateral inferior rectus eye corrected up to 20PD in primary position in our series, reducing this risk.

Modified Anterior Superior Oblique Tuck: A Case Series

PURPOSE

Selection of the ideal procedure to correct symptomatic excyclotropia depends on several factors including the degree of torsion and associated vertical, horizontal and pattern deviation. Selective tuck of the anterior temporal torsional fibers of the superior oblique (SO) tendon is an alternative procedure to the classical Harada-Ito. The purpose of this study is to report its stability and results.

METHODS

Retrospective review of all consecutive patients with symptomatic excyclotorsion of at least 5º (degrees) treated by selectively splitting and tucking the anterior temporal fibers of the SO tendon. Torsion in primary position was measured using the double Maddox Rods. Patients with additional symptomatic vertical or horizontal diplopia underwent simultaneous surgery on other extraocular muscles.

RESULTS

Five patients were studied. Mean age was 60 ± 8 years (47-67). Mean postoperative follow-up was 10 ± 8 months (3-21). The mean preoperative torsion of 11º±4º (7º-15º) significantly decreased to 3º±2º (p = .03) at the first postoperative visit (16 ± 9 days) and 3 ± 2º during the last visit (P = .03). The procedure corrected 1.4º±0.9º per mm of tuck. Postoperatively no patient complained of torsion. No undesirable vertical or horizontal deviations were noted.

CONCLUSION

This technique is a simple alternative to manage symptomatic excyclotorsion, with significant and stable relief of moderate amounts of torsion and without inducing unexpected vertical or horizontal deviation.

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.

Compartmental Strabismus

Recent reports confirm innervational compartments of select rectus extraocular muscles as well as the superior oblique.¹ Histopathological and orbital imaging studies demonstrate well defined compartmental innervation of the horizontal rectus muscles with less differentiation in the vertical rectus muscles. Acquired vertical misalignment not associated with cyclovertical muscle dysfunction has been associated with horizontal rectus muscle compartment dysfunction. Pattern and other forms of strabismus have been associated with segmental or compartmental abnormal innervation of the extraocular muscles. Taking advantage of segmental function and innervation, selective weakening and strengthening procedures have been used to treat patients with incomitant near/distance disparities, incomitant vertical and torsional strabismus, and patients with A- and V-pattern strabismus.

Central Mini-plication of the Medial Rectus for Convergence Insufficiency

Five cases with a mean (± SD) age of 61 (12.02) years are described to study the outcomes of treatment with central mini-plication of the medial rectus (MR) muscles in adult convergence insufficiency with diplopia and near exotropia: mean preoperative deviation: 18 (± 2) pd. Surgical outcome was considered to be favorable when diplopia and symptoms were resolved and final exotropia at near was ≤8 pd at the end of follow-up. A central mini-plication of the medial rectus (MR) muscles was performed in 5 patients (4 unilateral). Overcorrection at distance vision was recorded in 3 cases; this resolved by 3 months postoperatively. There was not overcorrection at near vision in any case. None of the cases operated on had overcorrection at the end of follow-up. The final horizontal deviation was ≤8 pd at near vision, except for 1 case. Symptoms and diplopia resolved in every case but 2/5 required reoperations. The mean follow-up was 8 (2.12) months. Central mini-plication of 1 or 2 medial rectus muscles can improve the symptoms and signs of exotropia associated with convergence insufficiency when exercises and the prisms are rejected by the patients and when these approaches have not solved the problem.

Indications and outcome of vertical rectus partial recessions

OBJECTIVE

To assess the indications and results obtained with partial vertical recti recessions in patients with diplopia and small-angle vertical strabismus (≤10 dp).

MATERIAL AND METHODS

A retrospective study was conducted on 9 patients that were operated on with partial temporal or nasal recession of the superior (SR) or inferior rectus (IR), during 2017. A good outcome was considered when diplopia was resolved in primary position and infraversion, at the end of follow-up.

RESULTS

A total of 9 cases were included, with a mean age 66.3 years (55.5% women), diagnosed with sixth nerve palsy (3), incomplete third nerve palsy (2), sagging eye (2), age related strabismus (1), and restrictive strabismus post-retinal surgery (1). Mean preoperative vertical deviation was 8.2 dp in primary position and the post-operative vertical deviation was 0.8 dp (mean difference was statistically significant, P=.007). In 4 cases, the SR was operated on (temporal pole in 3 and nasal in 1). The IR was operated on in 5 patients (temporal pole in 4 and nasal in 1). Mean recession was 3.77mm. In 55.5% of case diplopia was eliminated, and in a 33.3% a well-tolerated, intermittent diplopia persisted. A good outcome was obtained in 88.8% of the cases at the end of follow-up (mean: 7. 1 months), with no over-corrections.

CONCLUSIONS

Partial SR or IR recessions obtained good results in most of the cases with small angle vertical strabismus and diplopia. Although post-operative torsion or modification of the pre-operative torsion was not observed, a prior study should be made of torsion.

Plication as an alternative to resection in horizontal strabismus: A randomized clinical trial

Purpose:

Resections and plications tighten recti although the latter are less traumatic, potentially reversible, quicker, and vascularity preserving. To compare inflammation, scarring, and alignment in horizontal strabismus, operated uniocularly by either resections or plications (with recessions): recession and resection (R&R) or recession and plication (R&P) groups. This was a prospective, patient and assessor blind, randomized trial.

Methods:

All consenting strabismus patients qualifying for the first-time uniocular horizontal rectus surgeries underwent detailed ocular examination and were randomized into standard R&R or R&P groups. For the latter, we folded the tendon-muscle strap the desired amount using 6-0 polyglactin, suturing it to its insertion, entailing no disinsertion. We compared the groups for inflammatory grades (individually for congestion, chemosis, discharge, foreign-body sensation, and drop intolerance and aggregated to a total inflammatory score (TIS), scar visibility (SV) at 1 m, and successful alignment (≤10 prism diopter of orthotropia). We used Mann–Whitney and Fisher's exact tests, with significance at P ≤ 0.05.

Results:

We randomized 40 patients: 22 to R&R and 18 to R&P. The groups were comparable in age, strabismus onset and duration, and strabismus amount. The inflammatory scores, both individual and TIS, were comparable at all time-points: all P > 0.05. SV proportions were not significantly different: 16/22 in R&R versus 9/18 in R&P; P = 0.19. There were no significant differences in success rates: 14/22 versus 10/18, P = 0.74.

Conclusion:

Our study shows that plication is similarly effective as resection, when combined with recession in horizontal strabismus, and should be resorted to more frequently.

Anterior segment ischemia: etiology, assessment, and management

Anterior segment ischemia (ASI) is a potentially serious but rare complication of strabismus surgery. Among several risk factors, ASI occurs after strabismus surgery because of the nature of the anterior segment circulation. Disinsertion of rectus muscles leads to a decrease in the blood supply to the various anterior segment structures. We report a series of retrospective and prospective studies performed by our group focused on determining the risk of anterior segment ischemia following strabismus surgery, diagnosis, and modifications to surgical techniques to minimize the impact on anterior segment circulation. We found a significant decrease in postoperative anterior segment blood flow when operating vertical rectus muscles. Plication procedures preserve anterior segment circulation, and modifications to the technique allow the performance of adjustable sutures. Small adjustable selective procedures that spare the ciliary vessels have been demonstrated to be effective in patients with vertical and torsional diplopia. Ciliary sparing augmented adjustable transposition surgery decreases the risk of anterior segment ischemia while allowing management of potential post-operative alignment complications. Finally, ocular coherence tomography angiography is a valuable quantitative and qualitative technique to evaluate anterior segment ischemia. Strabismus surgeons should be aware of the risks of anterior segment ischemia when operating vertical rectus muscles. Modifications to standard surgical techniques allow surgeons to perform complex strabismus surgery in patients at risk for anterior segment ischemia.

What's new for us in strabismus?

Strabismus is one of the most challenging subspecialties encountered in the field of ophthalmology. The concept of etiology of strabismus is being advanced with the development of newer imaging modalities and increased understanding of the genetics of strabismus. Imaging is also being used to aid in the planning of strabismus surgery. Newer horizons are being explored in the amblyopia management. The good old eye-pad is being replaced with the iPad. Early detection of loss of stereopsis is being used to decide the timing for strabismus surgery. Improvement of binocular summation has been discovered as a benefit of corrective strabismus surgery. Newer surgical techniques such as new transposition procedures are being developed to correct complex strabismus. Strabismus surgeries aided by adjustable sutures have increased the precision of a strabismologist. A new light has been thrown on the psychosocial impact of strabismus. A present-day strabismologist has advanced from the goal of ocular alignment to a bigger perspective "to regain the paradise lost: stereopsis."

Small Deviations: Vertical, Horizontal, and Combined

INTRODUCTION AND PURPOSE

Symptomatic, small-angle strabismus is largely an acquired problem of adults that has previously been managed with prism spectacles. This paper will explore surgical options that are becoming increasingly popular.

METHODS

The special issues that confound surgical treatment of small-angle strabismus are considered. Surgical procedures described in the literature and in the author's experience that address these issues are reviewed.

RESULTS

Several recently described surgical techniques show promise for treatment of small-angle strabismus in adults. Their use is illustrated in a case report. Review of the author's practice shows a rapid increase in surgery for small-angle strabismus.

CONCLUSIONS

Surgical strategies for small deviations are increasingly important to meet the spectacle-free expectations of our adult patients.

Graded Marginal Recession: A Surgical Technique to Correct Small Angle Vertical Deviations

PURPOSE

To describe a novel muscle recession technique to surgically correct small angle vertical deviations in symptomatic adults with fusion potential.

METHODS

A novel technique involving a graded recession of the medial and lateral poles of a vertical rectus muscle, combined with graded medial and lateral tenotomy of the muscle, was used to treat small vertical deviations. A surgical nomogram was developed based on the configuration of the procedure and its predicted effects. Four patients with small angle hypertropia ranging from 1 to 5 prism diopters (PD) underwent the graded marginal recession procedure and were observed for up to 3 years.

RESULTS

Three of the four patients had successful correction of their strabismus and resolution of diplopia, with no complications or induced incomitance. One patient was initially orthotropic but showed a 2 PD regression 1 month postoperatively, eventually requiring additional surgery to achieve stable orthotropia.

CONCLUSIONS

The graded marginal recession can be safely and effectively used to correct very small vertical deviations in adults with fusion potential. A surgical nomogram can be created to guide predicted corrections in increments of less than 0.5 PD.

Minimal incision surgery in strabismus: Modified fornix-based approach

OBJECTIVE

To evaluate the modified fornix-based technique as an approach for minimal incision surgery in strabismus.

METHODS

The medical records of all consecutive patients that underwent strabismus surgery with fornix-based conjunctival incision between 2007 and 2012 were retrospectively reviewed. As a primary variable, an analysis was made of the wound size depending on the number of stitches. A descriptive study was performed on the variables related to patients and to the type of strabismus and surgery.

RESULTS

Out of 153patients identified, 138 with 294 surgeries were included. In 200 (68%) interventions, the incision was sutured with one stitch, in 77 (26.2%) with 2, in 13 (4.4%) with 3, and in 4 (1.4%) with 4, with the mean number of stitches being 1.39±0.64. The mean age of the patients was 39years (2-80), and 36 (26.1%) had previous strabismus surgery, with topical anaesthesia being used in 35 (25.4%) cases. At 3months after surgery deviation was ≤10DP in 114 (82.6%) patients. There were no wound-related complications.

CONCLUSIONS

The modified fornix-based technique is an effective and safe approach for minimal incision surgery in strabismus, in patients at all ages, with previous history of strabismus surgery and with topical anaesthesia.

Adjustable small-incision selective tenotomy and plication for correction of incomitant vertical strabismus and torsion

PURPOSE

To evaluate the effectiveness of adjustable small-incision selective tenotomy and plication of vertical rectus muscles in correcting vertical strabismus incomitant in horizontal gaze positions and cyclotorsion.

METHODS

The medical records of all patients who underwent adjustable small-incision selective tenotomy or plication of a vertical rectus muscle for correction of horizontally incomitant vertical strabismus or cyclotorsion by a single surgeon at a single eye institute from July 2013 to September 2014 were retrospectively reviewed. Selective tenotomy and plication were performed on either the nasal or temporal side of vertical rectus muscles, based on the direction of cyclotorsion and incomitance of vertical strabismus.

RESULTS

Of 9 patients identified, 8 (89%) had successful correction of horizontally incomitant vertical strabismus, with postoperative vertical alignment within 4(Δ) of orthotropia in primary position, lateral gazes, and downgaze. Of the 8 patients with preoperative cyclotorsion, 4 (50%) were successfully corrected, with <5° of cyclotorsion postoperatively. Of the 4 patients in whom cyclotorsion did not improve, 3 had undergone prior strabismus surgery, and 2 had restrictive strabismus. Eight of the 9 patients (89%) reported postoperative resolution of diplopia.

CONCLUSIONS

Adjustable small-incision selective tenotomy and plication effectively treat horizontally incomitant vertical strabismus. These surgeries may be less effective for correcting cyclotorsion in patients with restriction or prior strabismus surgery. Advantages are that they may be performed in an adjustable manner and, in some cases, under topical anesthesia.

The effect of rectus muscle recession, resection and plication on anterior segment circulation in humans

BACKGROUND

Plication is an alternative tightening procedure to resection. In monkeys, plication has been shown to preserve anterior segment circulation compared with full-tendon tenotomy, but this is unconfirmed in humans.

PURPOSE

To evaluate anterior segment circulation by iris angiography before and after strabismus surgery in humans.

METHODS

Prospective, blinded study of 14 patients (mean age (SD), 58.6 (14.3)) undergoing plication and/or full tendon tenotomy (resection or recession) from August 2013 to March 2014. Eight patients (mean age (SD), 59.0 (13.3)) underwent plication of one muscle with or without recession of a second muscle on the same eye and six patients (mean age (SD), 58.2 (16.8)) underwent tenotomy of one to two muscles on the same eye. Preoperative and postoperative iris angiograms were compared for changes in perfusion by a masked examiner. In patients undergoing binocular surgery, one eye was chosen preoperatively to be the study eye.

RESULTS

Postoperative iris filling defects were present in four patients (67%) after tenotomy and one patient (12.5%) after plication (p=0.09). Of the seven total vertical rectus muscles operated (three tenotomies and four plications), filling defects were present after three tenotomies and one plication (100% vs 25%; p=0.14). Of the 13 total horizontal rectus muscles operated (eight tenotomies and five plications), filling defects were present after one tenotomy and none of the plications (13% vs 0%; p=0.99).

CONCLUSIONS

Rectus muscle plication spares the ciliary vessels and may be considered a safer alternative to resection for patients at risk for anterior segment ischaemia, especially when surgery involves a vertical rectus muscle.

One Year of Pediatric Ophthalmology and Strabismus Research in Review

PURPOSE

To highlight recent advances in amblyopia and strabismus.

DESIGN

Literature review.

METHODS

A literature search of articles published in the English language was performed in PubMed or MEDLINE between May 2012 and April 2013 using the terms amblyopia or strabismus. Articles deemed relevant were selected.

RESULTS

The review highlights articles that increase our understanding of strabismus and amblyopia as well as newer treatment strategies.

CONCLUSIONS

The review highlights some new information and possible future advances in amblyopia and strabismus.

Rectus muscle plication using an adjustable suture technique

PURPOSE

Rectus muscle plication is an alternative muscle-strengthening procedure to rectus muscle resection. Possible advantages of rectus muscle plication include a lower risk of "lost" muscles and anterior segment ischemia.

METHODS

This was a retrospective case series describing a surgical procedure for rectus muscle plication using an adjustable suture technique that can be used on any of the four rectus muscles.

RESULTS

A total of 5 adult patients underwent adjustable suture plication procedures. Of these, 2 patients required suture adjustment postoperatively. At the final follow-up visit, all the patients maintained satisfactory ocular alignment within 6(Δ) of orthotropia for horizontal deviations and 2(Δ) of orthotropia for vertical deviations. Diplopia was eliminated in all cases with preoperative diplopia. There were no postoperative complications or unexpected shifts in ocular alignment.

CONCLUSIONS

Rectus muscle plication using this adjustable suture technique may serve as an alternative to rectus muscle resection and may be particularly useful in patients who are at risk for anterior segment ischemia or those in whom a shorter anesthesia time is recommended.