|Year : 2019 | Volume
| Issue : 1 | Page : 1-8
Management of restrictive strabismus
Department of Ophthalmology, Helwan University, Helwan, Egypt
|Date of Submission||08-Dec-2018|
|Date of Acceptance||20-Dec-2018|
|Date of Web Publication||26-Apr-2019|
2 Morrison Street, Rouchdy, Alexandria
Source of Support: None, Conflict of Interest: None
Aim of the study This study aimed to target a special type of strabismus, the restrictive type, with prediction of its problems, diagnostic, management, and results.
Patients and methods This is a prospective randomized study performed in Alexandria. The participants of this study were 42 patients having restricted strabismus, with different diagnostic criteria, such as abnormal ocular deviation with the movement of the globe defective and not reaching the midline, abnormal position of the head, forced duction test, and anatomical changes found during surgery.
Results The cases of restrictive strabismus included congenital cases including monocular elevation deficit, Brown’s syndrome, congenital fibrosis of extraocular muscles, oculomotor nerve palsy, and long-standing strabismus, especially unilateral presenting in old age. Cases needed specific diagnostic procedure such as forced duction test to be performed preoperatively and intraoperatively, and postoperative results were satisfactory in most cases except cases that underwent previous surgery with muscle resection, aggravating the condition and leading to more restrictions.
Conclusion Cases of restrictive strabismus, when properly diagnosed, with special considerations, could arrive at a postoperative satisfactory outcome.
Keywords: Brown’s syndrome, congenital fibrosis of extraocular muscles, Duane’s retraction syndrome, esotropia, exotropia, inferior rectus, lateral rectus, monocular elevation deficit, oculomotor palsy, third nerve palsy
|How to cite this article:|
Gaballah K. Management of restrictive strabismus. J Egypt Ophthalmol Soc 2019;112:1-8
| Introduction|| |
Restrictive strabismus is one of the types of strabismus that is related to many underlying causes; some of which are congenital, such as congenital fibrosis of extraocular muscles (CFEOM) which is a rare type, Brown syndrome, and Duane retraction syndrome (DRS), going to nerve palsies when long-standing, leading to restrictive muscle changes; also orbital inflammatory causes such as thyroid ophthalmopathy; and also, long-standing monocular strabismus, which could present in old age by restrictive muscle changes.
The congenital fibrosis syndromes are rare inherited strabismus syndromes that present as congenital, nonprogressive ophthalmoplegias with active and passive restriction of globe movement, and include classic and atypical forms of CFEOM and Duane syndrome .
Among all cases of ocular misalignment from cranial nerve palsies, third nerve palsies are important because a subset of these are caused by life-threatening aneurysms. The true incidence of third nerve palsies and the relative incidence of the various etiologies are largely unknown .
Clinical findings of acquired third nerve palsy depend on the affected area of the oculomotor nerve track. It can be divided into partial or complete palsy. Complete third nerve palsy presents with complete ptosis, with the eye positioned downward and outward and unable to adduct, infraduct, or supraduct, and dilated pupil with sluggish reaction ,. Partial third nerve palsy is more common and presents with a variable duction limitation of the affected extraocular muscles and with variable degree of ptosis and/or pupil dysfunction .
Duane syndrome, also called DRS, is a congenital and nonprogressive type of strabismus owing to abnormal development of the sixth cranial nerve. It is characterized by difficulty in rotating one or both eyes outward (abduction) or inward (adduction). There may also be changes of eyelid position on attempted movement of the eyes. It is one of the causes of restrictive strabismus.
Surgery cannot actually fix the problem of nerves that are miswired but can move muscles to compensate for the miswiring. Because surgery cannot fix the problem of the abnormal nerves, surgery cannot restore normal eye movement. However, surgery can (and usually does) substantially improve the situation .
| Patients and methods|| |
This is a prospective study carried out in an Ophthalmology Centre in Alexandria, starting from December 1, 2014, till May 1, 2015, and included all patients with restrictive strabismus. All patients and parents of patients under 18 years old , have signed an informed written consent to be included in the study. Cases are followed for 6 months, till November 2015, with the last case followed up.
All participants of the study or the parents of children signed an informed consent before starting of the study.
A total of 42 patients diagnosed as having restrictive strabismus attended the ophthalmology clinic. The diagnosis depended on any of the following criteria: abnormal position of the eyes, one or both in primary position; abnormal position of the head such as neck extension; limitation of ocular movement; and the diagnostic forced duction test.
Management and choice of surgical technique was tailored to each patient according to clinical findings, forced duction test, and anatomical findings during surgery.
Inclusion criteria were any of the following:
- Cases of large angle of deviation, horizontal or vertical.
- The eyes not able to move post to midline.
- Cases with abnormal head posture such as chin elevation.
- Cases of strabismus, where all should have positive forced duction test result.
| Results|| |
A total of 42 patients participated in this study, with 22 males and 20 females. Their age ranged from 2 to 62 years. The diagnosis started with diagnosis of strabismus, which is the eye movement testing of both duction movements and version movements in all gaze directions. When there was a gross limitation of movements of one of the muscles, not reaching the midline, this was very suspicious of the presence of a restriction component, as is seen in all cases of restrictive long-standing esotropia or exotropia presenting in old age. These constituted 13 cases of long-standing exotropia, with seven males and six females, and 12 cases of long-standing esotropia, with ten males and two females. Another diagnostic point, was the abnormal eye position, either down or out, accompanied by abnormal compensatory head posture, as in cases of CFEOM, which constituted four cases of this study, one male and three females ([Figure 1] and [Table 1] and [Table 2]).
|Figure 2 (a) Right MED, hypotropia. (b) Defective elevation in adduction. (c) Defective elevation in abduction. MED, monocular elevation deficit.|
Click here to view
|Figure 3 (a) Right MED, hypotropia, ptosis. (b) Same case, pseudoptosis, jaw winking. (c) Defective elevation. (d) Postoperative, after right inferior rectus recession. MED, monocular elevation deficit.|
Click here to view
|Figure 5 (a) Left oculomotor palsy, LR restriction. (b) Left LR restriction preoperative. (c) Left oculomotor palsy postoperative. (d) Diagram of muscle changes in left oculomotor palsy. LR, lateral rectus.|
Click here to view
|Figure 6 Right oculomotor palsy, previous three surgeries, immobile eye, ptosis, hypertropia, and enophthalmos.|
Click here to view
There were two cases of Brown’s syndrome, and both were females. One of them, aged 7 years, had accommodative esotropia, with hypotropia of the left eye in adduction, but this patient was only followed up for her clinical appearance was acceptable. The other one was a female with right Brown’s syndrome, with severe right hypotropia in adduction and positive forced duction test for superior oblique, and this case was managed by superior oblique partial disinsertion of the fibrotic part of the tendon, and the outcome was satisfactory ([Figure 7]a, b).
|Figure 7 (a) Right Brown’s syndrome preoperatively. (b) Right Brown’s syndrome postoperatively.|
Click here to view
Cases of CFEOM represented four cases, with one male and three females. The boy aged 12 years had bilateral ptosis, bilateral severe restrictive hypotropia, and neck extension. Forced duction test for the two inferior recti was positive, which was operated by attempted recession of inferior recti by hang back recession, but the inferior recti were too tight, narrowing the surgical field and making the only solution disinsertion of the two inferior recti. Postoperative appearance was correction of hypotropia and correction of neck extension, but still the ptosis had to be corrected, and he was sent to an oculoplastic surgeon, but the parents did not sign consent for lid surgery ([Figure 8]a–c).
|Figure 8 (a) CFEOM, hypotropia, and ptosia preoperatively. (b) CFEOM after bilateral IR disinsertion. (c) CFEOM, postoperatively and no hypotropia. CFEOM, congenital fibrosis of extraocular muscle; IR, inferior rectus.|
Click here to view
Another case of congenital fibrosis syndrome was a female, aged 28 years, having severe hypotropia and exotropia in both eyes with jaw winking and neck extension compensatory for the hypotropia eyes. Forced duction test was positive for the inferior recti and lateral recti. This patient was managed by bilateral disinsertion of the inferior recti, which were found too tight, with no place for taking sutures, and bilateral lateral recti recession with hang back. The postoperative results of this patient were very satisfactory to the patient and parents ([Figure 9]a–c).
|Figure 9 (a) CFEOM, exotropia, hypotropia, and jaw winking. (b) Same patient, jaw winking, preoperatively. (c) CFEOM postoperatively after bilateral IR disinsertion, bilateral LR hang-back recession. CFEOM, congenital fibrosis of extraocular muscle; IR, inferior rectus; LR, lateral rectus.|
Click here to view
Cases of DRS represented three cases, with one male and two females; one of them, a young girl of 2 years, had left esotropia, DRS type III, severe globe narrowing with adduction, upshoot on attempted adduction, and severe restriction of left medial rectus (MR) detected by positive forced duction test, which was managed by recessing the left MR 6 mm, with hang back ([Figure 10]a–d).
|Figure 10 (a) Left DRS I preoperative. (b) Same patient, upshoot in adduction, preoperative. (c) Same patient postoperative, esotropia corrected. (d) Same patient postoperative, no upshot. DRS, Duane retraction syndrome.|
Click here to view
Another boy with restriction of left MR was operated with left MR recession, and the results are satisfactory. A third case, a girl of 29 years, had left DRS I, eyes were parallel in primary position, defective abduction, and mild restriction of left later a rectus. She was only followed up, where there was no indication of surgery in this case ([Figure 11]a–c).
|Figure 11 (a) Left DRS I syndrome, eyes parallel in primary position, only follow-up. (b) Same patient, mild left palpebral fissure narrowing, but no indication for surgery. (c) Left defective abduction (DRS I) same patient. DRS, Duane retraction syndrome.|
Click here to view
Long-standing cases of unilateral strabismus, which remained unoperated for many years, represented with unilateral exotropia in 13 cases and with long-standing esotropia in 12 cases, which constituted one of the main causes of restricted strabismus, and were operated by recession of lateral rectus recession in 10 cases of exotropia, whereas three cases of long-standing exotropia refused to be operated. Moreover, among the 12 cases of esotropia, 10 cases were operated by-hang back recession of MR, and two cases were operated by disinsertion of the medial rectus, but in the postoperative period, there was recurrence of esotropia.
One male aged 25 years presented with right exotropia with right lateral rectus restriction after vitrectomy. This man was operated, and silicon particles were found solidified under and around the lateral rectus. Then recession of lateral rectus which was found healthy, nonfibrotic, and forced duction test became negative , then resection of medial rectus. The postoperative results were satisfactory ([Figure 12]a–c).
|Figure 12 (a) Right exotropia after vitrectomy. (b) Intraoperative, silicon particles around LR. (c) Same patient postoperatively. LR, lateral rectus.|
Click here to view
| Discussion|| |
Cases of restrictive strabismus constitute a special type of strabismus with specific presentation and anatomical changes of one or more of extraocular muscles that have specific presentation, confirmed by forced duction test, and requiring some modifications in the surgical management, as starting by operating on the restrictive muscles and relieving the restriction, until getting negative forced duction test result by the end of surgery. Sometimes, in severe restriction, the surgical field is too narrow, and the suturing of the muscle needed before recession is impossible in many cases, making the disinsertion of the muscle the only possible solution, like in two cases of CFEOM, and two cases of long-standing esotropia.
Regarding the studies for cases of monocular elevation deficit, in this study, one patient did not need surgery; although having restriction of inferior rectus by forced duction test, the eyes were in the same horizontal level. The second patient, a girl with right hypotropia, and tight inferior rectus, was operated by right inferior rectus recession, but the right lower lid sagging occurred postoperatively, and this was owing to inadequate dissection of the right inferior rectus from the lower lid retractors. This was considered in the third patient who had right hypotropia, pseudoptosis, and jaw winking, and this was corrected adequately. The goal of surgery is to improve the position of the affected eye in primary gaze, by increasing the field of binocular vision. If restriction to upgaze is demonstrated on the forced duction test (FDT), inferior rectus muscle restriction is present. An inferior rectus recession with conjunctival recession should be done ,.
Regarding the cases of oculomotor nerve palsy, one young boy with right ptosis and external ophthalmoplegia, was not operated in the study period, and another one operated by full lateral rectus recession and medial rectus resection and was greatly ameliorated.
[Figure 6] presents a girl, who came previously operated from oculomotor palsy. Three previous surgeries came with ptosis, enophthalmos, hypertropia, and severe restriction in all directions, making us to be very cautious and avoid resection as much as possible.
In other studies, cases with oculomotor nerve palsy in one eye were treated by superior oblique tendon transposition to a point anterior and medial to the insertion of the superior rectus muscle. Additionally, large recessions of the lateral rectus muscle of involved eyes and, occasionally, recess/resect procedures of horizontal recti muscles of noninvolved eyes were performed .
Regarding the cases of Brown syndrome in this study, one girl needed right superior oblique tendon release and improved greatly ([Figure 7]a, b).
Some people with congenital Brown syndrome may not require treatment. Alignment of the eyes may improve with age, especially in those children whose eyes are normally aligned when looking straight ahead. Other individuals with Brown syndrome may require surgery to correct the alignment of the eyes. The results of surgery are usually excellent, but the condition may recur ,,.
Cases of CFEOM, were greatly improved. A boy still needed further lid surgery for ptosis, and the other two, one unilateral and one bilateral, had their lid position corrected spontaneously after correction of the eye position.
Previous studies showed that patients with this congenital, nonprogressive disorder have restrictive ophthalmoplegia and eye misalignment, with severe congenital ptosis and a resulting prominent chin-up head position. Deficits of vertical eye movements, especially upgaze, are a hallmark of the condition, and patients’ eyes are often stuck in infraduction. The horizontal eye movement deficits are more variable, ranging from full horizontal motility to nearly complete ophthalmoplegia. Eye alignment in primary position can be exotropic, esotropic, or straight ,.
In this study, we had one patient with right restrictive strabismus after vitrectomy, and this patient was explored. Silicon particles were removed from underneath the right lateral rectus, restriction relieved, and then strabismus corrected by recess resection procedure, with satisfactory result ([Figure 12]a–c).In a previous study, the medical records of 18 patients who underwent strabismus surgery following a scleral buckling procedure were obtained and were investigated for the effect of multiple variables on postoperative alignment after strabismus surgery. Outcomes were considered successful if there was less than or equal to 10 prism diopters residual horizontal and/or less than or equal to 4 prism diopters residual vertical deviations .
| Conclusion|| |
Cases of restrictive strabismus should have special goals in management; first eye position correction, with taking in consideration the gross limitation of movements, and the forced duction test, avoid muscle resection as possible. The best technique is recession with hang-back technique or muscle disinsertion if difficult muscle manipulation, or severe narrow field of surgery as in the cases of severe hypotropia in CFEOM.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Engle EC. The genetic basis of complex strabismus. Pediatr Res 2006; 59:343–348.
Fang C, Leavitt JA, Chen JJ. Incidence and etiologies of acquired third nerve palsy using a population-based method. JAMA Ophthalmol 2017; 135:23–28.
American Academy of Ophthalmology. Basic and clinical science course. Section 5: neuro-ophthalmology, chapter 8 . The patient with diplopia2010-2011 . P 228–229.
Miller N, Newman N. Clinical neuroophthalmology 5th ed. Miller NR, Newman NJ Baltimore: Williams & Wilkins; 1998. 1194–1223.
Capo H, Warren F, Kupersmith M. Evolution of oculomotor nerve palsied. J Clin Neuroophthalmol 1992; 12:21–25.
Alexandrakis G, Saunders RA. Duane retraction syndrome. Ophthalmol Clin North Am 2001; 14:407–417.
Talebnejad MR, Roustaei GA, Khalili MR. Monocular elevation deficiency: a case series of surgical outcome. Iran J Med Sci 2014; 39:102–106.
Raab EL, Abay AA, Bloom JN, Edmond JC, Lueder GT. Pediatric ophthalmology and strabismus2010-2011. San Francisco, CA: American Academy of Ophthalmology; 2011. 221.
Gottlob I, Catalano RA, Reinecke RD. Surgical management of oculomotor nerve palsy. Am J Ophthalmol 1991; 111:71–75.
Stolovitch C, Leibovitch L, Lowenstein A. Long-term results of superior oblique tendon elongation for Brown syndrome. J Pediatr Ophthalmol Strabismus 2002; 39:90–93.
Maggi R, Maggi C. Tendon surgery in Brown syndrome. J Pediatr Ophthalmol Strabismus 2002; 39:33–38.
Capasso L, Torre A, Gagliardi V, Magli A. Spontaneous resolution of congenital Brown syndrome. Ophthalmologica 2001; 215:372–375.
Heidary G, Engle EC, Hunter DG. Congenital fibrosis of the extraocular muscles. Semin Ophthalmol 2008; 23:3–8.
Graeber CP, Hunter DG, Engle EC. The genetic basis of incomitant strabismus: consolidation of the current knowledge of the genetic foundations of disease. Semin Ophthalmol 2013; 28:427–437.
Chang JH, Hutchinson AK, Zhang K, Lambert SR. Strabismus surgery outcomes after scleral buckling procedures for retinal detachment. Strabismus 2013; 4:235–241.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12]
[Table 1], [Table 2], [Table 3]