Surgical correction of hypotropias associated with thyroid dysfunction

Risk Factors for Reoperation after Strabismus Surgery among Patients with Thyroid Eye Disease

PURPOSE

To examine risk factors for strabismus surgery reoperation in patients with thyroid eye disease (TED).

DESIGN

Retrospective cohort study.

METHODS

An insurance claims database was used to identify patients with TED who underwent at least one strabismus operation between 2003 and 2019. We recorded specific muscles operated on, as well as the timing and frequency of reoperations. Cox regressions were used to estimate associations between time to reoperation and patient and primary surgery characteristics.

RESULTS

Of the 448 patients who met inclusion criteria, 111 (24.8%) underwent a reoperation. Patients were followed for an average of 5.4 ± 3.0 years after their initial strabismus surgery. The rates of reoperation among patients whose initial surgery involved horizontal muscles only, vertical muscles only, and horizontal and vertical muscles were 29 of 120 (24.2%), 33 of 169 (19.5%), and 49 of 159 (30.8%) respectively (P = .05). The number of muscles operated on initially was the only independent predictor for undergoing a strabismus surgery reoperation (odds ratio, 1.27; 95% confidence interval, 1.03-1.57; P = .03). The number of muscles operated on initially was also associated with shorter time to first reoperation (hazard ratio, 1.22; 95% confidence interval, 1.02-1.46; P = .03). Age at first surgery, time between diagnosis of TED and first strabismus surgery, gender, race, and use of adjustable sutures were not associated with time to reoperation.

CONCLUSIONS

Approximately 1 in 4 patients with TED require reoperation after strabismus surgery. The number of muscles operated on was the only independent predictor for both undergoing a reoperation and time to first reoperation.

Surgical outcomes of unilateral recession-resection for vertical strabismus in patients with thyroid eye disease

PURPOSE

To present the surgical outcomes of vertical muscle resection in patients with thyroid eye disease (TED).

METHODS

The medical records of 6 patients who underwent unilateral vertical muscle recession-resection to correct vertical strabismus in TED were reviewed retrospectively for postoperative angle of vertical deviation on days 1 and 7 and at months 1, 3, 6, and 12. Surgery was considered successful if the vertical deviation was ≤4^Δ. Reoperation rates and complications were also noted.

RESULTS

The mean preoperative angle of vertical deviation was 39.2^Δ ± 3.8^Δ, and the mean final ocular deviation at 12 months postoperatively was 3.8^Δ ± 5.9^Δ. There was significant reduction in postoperative vertical deviation (paired t test, P < 0.001). Surgery was successful in 4 patients (67%). There was neither unusual postoperative inflammation nor increased restriction of the resected muscle postoperatively in any patient.

CONCLUSIONS

Based on careful assessment and appropriate patient selection, vertical muscle resection can be considered an effective option that provides satisfactory surgical outcomes with regard to vertical deviation correction in TED.

Surgical Responses of Medial Rectus Muscle Recession in Thyroid Eye Disease-Related Esotropia

We evaluate the surgical outcomes and surgical responses of medial rectus muscle (MR) recession patients with thyroid eye disease (TED)-related esotropia (ET). The surgical dose-response curves 1 week postoperatively and at the final visit were analyzed. Univariable and multivariable linear regression analyses were applied to investigate factors influencing surgical dose-response. A total of 43 patients with TED-related ET that underwent MR recession were included. The final success rate was 86.0% and the rate of undercorrection was 14.0%. The surgical dose-response curves of TED-related ET showed a gentle slope compared with those of standard surgical tables. In the univariable model, simultaneous vertical rectus muscle recession was the only significant factor influencing surgical dose-response of MR recession in TED-related ET (β = -0.397, P = 0.044). In a model adjusted for age, sex, type of surgery, and preoperative horizontal angle of deviation, simultaneous vertical rectus muscle recession showed marginal significance (β = -0.389, P = 0.064). The surgical dose-response curve of TED-related ET was unique. Simultaneous vertical rectus muscle recession was associated with increased surgical dose-response in TED-related ET.

The surgical management of strabismus with large angle in patients with Graves’ ophthalmopathy

BACKGROUND

Strabismus with large deviation in Graves' ophthalmopathy is relatively common in developing countries, such as China. However, little information is available in the literature on this condition. We report here our surgical results of strabismus with large deviation in Graves' ophthalmopathy.

PATIENTS AND METHODS

The surgical management of strabismus in 27 patients with Graves' ophthalmopathy with large angle (>or=25 degrees) were retrospectively analyzed. The strabismus surgery included recession or free tenotomy of involved rectus muscle, recession of rectus plus resection of ipsilateral antagonist, and recession of rectus plus recession of contralateral antagonist. The patients were followed up for an average of 1.2 years.

RESULTS

Among 27 patients, 17 were male and 10 were female, with their age ranging from 28 to 68 years old (mean: 51.9 years). There were 12 cases with excellent results, 10 with good results, 3 with fair results, and 2 with poor results. Only one surgery was required in all cases except three who needed re-operation. Based on the rectus muscles involved, just one rectus muscle recession combined with traction suture could correct the strabismus with large angle in 20 patients; two muscles were required in 9 patients and three in 1 patient. Four patients had surgical overcorrection of strabismus. Eight patients had complicated eyelid retraction postoperatively.

CONCLUSIONS

The surgical management of strabismus with large deviation in patients with Graves' ophthalmopathy was remarkably good. Just one rectus muscle recession combined with traction suture could correct the large angle strabismus in 74% (20/27) of cases. The choice of surgical procedure and some special attention in performing surgery are discussed.

Comparison of two different surgical techniques for the treatment of strabismus in dysthyroid ophthalmopathy

BACKGROUND

Surgical management of strabismus caused by dysthyroid ophthalmopathy has a history of variable success outcomes ranging from 43% to 82%. Previous studies showed that correcting the restricted duction seen in thyroid eye disease, rather than the deviation as is done in other types of strabismus surgery, resulted in markedly improved success rates. Other investigators have recommended a change in the approach to the surgical management of dysthyroid ophthalmopathy.

METHODS

Retrospective comparison of sequential case series.

RESULTS

The data of 86 patients were retrospectively reviewed, including 52 in the deviation correction group and 34 in the duction correction group, with 74 deviation correction operations and 47 duction correction operations. A successful outcome, defined as postoperative deviation less than or equal to 5(Delta), was seen in 72% of deviation corrections operations and 66% of duction correction operations (p = 0.55).

CONCLUSIONS

In our study, no difference in outcome between surgical corrections of restricted duction versus deviation was demonstrated.

Correction of restricted extraocular muscle motility in surgical management of strabismus in graves' ophthalmopathy

OBJECTIVE

To compare the success rates for strabismus surgery designed to correct limitation of duction with surgery designed to correct deviation in patients with Graves' ophthalmopathy.

DESIGN

Retrospective nonrandomized comparative trial.

PARTICIPANTS

One hundred thirty-seven patients with Graves' ophthalmopathy who had undergone at least one extraocular muscle surgery were divided into two groups: those whose first surgery occurred before June 1997 (control group) and those whose first surgery occurred in June 1997 or thereafter (case group).

INTERVENTIONS

Extraocular muscle surgery primarily directed at either correcting deviation (control group) or correcting limitation of ductions (case group).

MAIN OUTCOME MEASURES

Postoperative deviations in the primary position were measured in prism diopters 30 to 180 days after surgery. A postoperative deviation of less than 5 diopters was considered a successful surgical outcome.

RESULTS

Patients undergoing strabismus surgery specifically designed to correct limitation of duction achieved a 74% success rate compared with a 44% success rate in the control group (P < 0.01). Furthermore, the rate of reoperation in this group was only 27% compared with 44% in the control group (P < 0.04).

CONCLUSIONS

Compared with surgery aimed primarily at the correction of deviation, extraocular muscle surgery tailored to address restriction of ductions in patients with Graves' ophthalmopathy is associated with improved surgical success of initial realignment and with a lower rate of reoperation

The role of restricted motility in determining outcomes for vertical strabismus surgery in Graves' ophthalmology

OBJECTIVE

To identify factors predictive of operative success or failure for vertical muscle surgery performed in patients with Graves' ophthalmopathy.

DESIGN

Prospective noncomparative case series.

PARTICIPANTS

Thirty-one consecutive patients with Graves' ophthalmopathy who demonstrated vertical ocular motor imbalance, with or without simultaneous horizontal muscle imbalance.

INTERVENTION

Vertical extraocular muscle surgery performed either in isolation or in association with horizontal muscle surgery.

MAIN OUTCOME MEASUREMENTS

Vertical limitations of extraocular muscles were correlated with preoperative hypertropia. Stepwise linear regression was used to determine the significant predictors of postoperative hypertropia in primary gaze. Logistic analysis was used to estimate the probability of surgical failure (>5 diopters) on the basis of preoperative parameters.

RESULTS

The amount of preoperative hypertropia was negatively correlated with total restriction of vertical ductions (r = -0.52, P < 0.01). Preoperative hypertropia was positively correlated with asymmetry in muscle restriction between the two eyes (r = 0.67, P < 0.0001). The best predictor of preoperative hypertropia was the difference between restriction of the contralateral opposing recti, namely the right superior rectus, and the left inferior rectus, as well as the right inferior rectus and the left superior rectus (r = 0.74, P < 0.0001). Restriction of the contralateral opposing recti was also the most significant predictor of surgical success (postoperative hypertropia < 5 prism diopters).

CONCLUSIONS

Surgery tailored to address restriction of ductions, specifically the difference between contralateral opposing recti, is likely to improve the success of initial surgery beyond that based primarily on the magnitude of the vertical deviation.

Bilateral inferior rectus muscle recession for correction of hypotropia in dysthyroid ophthalmopathy

PURPOSE

The restrictive myopathy of dysthyroid ophthalmopathy frequently results in strabismus and diplopia. The most common deviation is hypotropia. Ipsilateral inferior rectus muscle recession, the generally accepted treatment, may lead to a progressive marked overcorrection. The purpose of this study is to evaluate the results of bilateral asymmetric inferior rectus muscle operations with regard to late progressive overcorrection.

METHODS

A retrospective review of all patients undergoing bilateral inferior rectus muscle recession for dysthyroid ophthalmopathy between 1993 and 1997 found 8 patients with hypotropia resulting from dysthyroid ophthalmopathy. Alignment and motility were assessed preoperatively and postoperatively in all patients. Bilateral asymmetric inferior rectus muscle recession was performed on all patients with an adjustable suture performed on the hypotropic eye. A successful, long-term, postoperative result was defined as orthophoria or a vertical misalignment of less than or equal to 5 PD in primary gaze.

RESULTS

Data were collected from 8 patients at 4 to 6 weeks postoperatively. Six patients had successful alignment, and 2 patients remained undercorrected. Seven patients were successfully aligned, and 1 patient was undercorrected at the latest postoperative examination (mean, 18 months).

CONCLUSION

In our series, bilateral asymmetric inferior rectus muscle recession resulted in successful correction of hypotropia without late postoperative overcorrections in patients with dysthyroid ophthalmopathy.

Long-term results of adjustable suture surgery for strabismus secondary to thyroid ophthalmopathy

PURPOSE

To review the results of adjustable suture surgery in patients with strabismus secondary to thyroid ophthalmopathy to determine long-term outcome and to identify postoperative complications.

METHODS

The records of 1524 patients with thyroid ophthalmopathy were retrospectively reviewed to identify those who required treatment for strabismus in the ocular motility clinic. Treatment consisted of adjustable suture surgery, prisms, or both. Elimination of diplopia in primary and reading positions was used at the criterion for success.

RESULTS

Forty-seven patients were treated with adjustable suture surgery, with an average follow-up of 41 months. Results after 1 or more surgeries were: 47% excellent, 26% good, 19% fair, and 9% poor. Significant postoperative complications included eyelid retraction and A-pattern exodeviation. Sixteen of 18 patients with fair or poor outcomes after the initial surgery were recognized within 6 months. Postoperative changes in vertical deviation from primary position to downgaze were predictive of postoperative diplopia in downgaze. Analysis of multiple preoperative characteristics showed no statistically significant associations with outcome. Eight additional patients had adequate relief of diplopia using prisms alone, with an average follow-up of 49 months.

CONCLUSIONS

Long-term symptomatic relief of diplopia was obtained in the majority of patients using adjustable suture strabismus surgery, combined occasionally with small amounts of prism postoperatively. Prisms alone provided effective long-term relief in patients with small-to-moderate deviations.

Late overcorrection of hypotropia in Graves ophthalmopathy. Predictive factors

The authors have occasionally noted Graves ophthalmopathy patients with stable, restrictive hypotropia who demonstrate excellent initial postoperative realignment, only to develop marked overcorrection within weeks to months after surgery. The charts of 12 consecutive patients who underwent a first operation for single, uncomplicated vertical muscle imbalance were evaluated. Five patients were identified who developed an overcorrection 2 to 5 months after surgery (overcorrected group). A stable comparison group of seven patients retained stable orthotropia after surgery. In cases of patients with late overcorrection, proptosis and superior rectus muscle volume, as measured preoperatively, were significantly greater than in the stable comparison group. There also was postoperative limitation of infraduction in most instances.

Botulinum toxin for the treatment of dysthyroid ocular myopathy

Eight consecutive patients with acquired deviations due to dysthyroid ocular myopathy were injected with botulinum A toxin for relief of their diplopia. Seven patients were acute in the onset of symptoms and one was chronic. All showed improvement in motility and experienced a reduction if not total relief of their symptoms. Six patients required reinjection. Complications were limited to transient ptosis, transient involvement of adjacent muscles and transient but prolonged paralysis that eventually resolved. No systemic complications were noted. We conclude that chemodenervation with botulinum A toxin may have a role in the management of dysthyroid ocular myopathy not amenable to prism treatment and may act as an adjunct to or eliminate the need for surgical correction in some patients.

Complications following surgery for thyroid ophthalmopathy

A marked reaction postoperatively was noted following strabismus surgery for thyroid ophthalmopathy. Preoperatively, the right eye was noted to have a small amount of lower nasal conjunctival injection and chemosis while the left eye was quiet. Only the right eye had the severe inflammatory reaction postoperatively, while the left eye responded normally. The findings included marked proptosis, chemosis, subconjunctival hemorrhage, corneal exposure and drying with a sterile ring infiltrate, corneal thinning and vascularization, and ocular immobility. The treatment and course of these complications is described. It is suggested that muscle surgery be deferred in patients with thyroid ophthalmopathy when there are signs of continued inflammation.

Extraocular muscle surgery for dysthyroid myopathy

A series of 45 patients underwent extraocular muscle surgery for diplopia induced by dysthyroid myopathy. Two thirds (31) of the patients were female and age distribution showed a peak (47%) in the sixth decade of life. The most common deviation was pure hypotropia; a combination of hypotropia and esotropia was also frequent. Initial surgical intervention restored binocularity in primary position in 30 patients and in reading position in 27 patients. After further surgery in some cases, 40 patients eventually achieved satisfactory alignment in primary position and 36 achieved it in reading position.

Paretic thyroid myopathy

Reports of vertical deviation in Graves' disease in recent years have always been associated with restrictive phenomena and positive forced duction testing, usually related to a tight inferior rectus. Two cases of medically proven Graves' diseased of ten-year duration are presented with increasing vertical disparity. Forced duction testing showed no restriction. Saccadic velocity tests using electro-oculography confirmed paresis of the inferior rectus in both cases. No cases of "true" vertical extraocular muscle paresis in chronic Graves' disease have been reported in the American literature.

Differential intraocular pressure in strabismus diagnosis

An evaluation of the differential intraocular pressure test in the diagnosis of non-comitant strabismus is described and the results compared with findings in ten normal subjects. Increased intraocular pressure occurring when an eye cannot complete a full duction indicates both the existence of a restriction and the presence of underlying muscle force generation. The differential intraocular pressure test is easily performed, non-invasive, generally reliable, and can be performed on children who are unlikely to cooperate with other types of diagnostic procedures. Although false-negative results may occur, this test nevertheless provides useful additional information to that normally obtained in a motility examination. When combined with passive forced ductions, an accurate picture of both active and passive components of the strabismus may be determined.