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Full Vertical Rectus Muscle Transposition Combined with Medial Posterior Fixation Sutures for Patients with Adduction Deficiency
Full Vertical Rectus Muscle Transposition Combined with Medial Posterior Fixation Sutures for Patients with Adduction Deficiency Moshe Snir, MD,1,2 Ronit Friling, MD,1 Hadas Kalish-Stiebel, MD,2 Ilana Sherf, MO,1 Dov Weinberger, MD,1 Ruth Axer-Siegel, MD2 Purpose: To compare the surgical and functional results of full tendon rectus muscle transposition to the medial rectus muscle augmented with posterior medial fixation sutures in patients with adduction deficiency (ADD) and Duane’s syndrome type 2. Design: Retrospective nonconcurrent interventional comparative case series. Participants: Twelve consecutive patients with ADD and Duane’s syndrome type 2. Interventions: Six patients treated by the full tendon rectus muscle transposition procedure alone were compared with 6 patients treated by the full tendon rectus muscle transposition combined with posterior medial fixation sutures. Main Outcome Measures: Postoperative ocular alignment, duction improvement, binocular functions, and reoperation. Results: In the augmented surgery group, mean distance and near deviation decreased by 74.5% and 74%, respectively, versus 56% and 59%, respectively, in the control group (P ⫽ 0.007 and 0.02, between-group comparison for distance and near deviation, respectively). Mean duction improved in 73% of the study group compared with 52% of controls (P ⫽ 0.025). No postoperative complications or duction anomalies were observed during follow-up in the entire cohort; reoperation was needed in 1 patient in the study group and in all 6 patients in the control group. Conclusions: The augmented full vertical rectus muscle procedure is a beneficial surgical approach for patients with ADD and Duane’s retraction syndrome type 2, reducing the need for multiple extraocular muscle surgery. Ophthalmology 2005;112:939 –943 © 2005 by the American Academy of Ophthalmology.
Partial or full tendon transposition procedures1– 8 were introduced for the treatment of complex ocular motility abnormalities on the assumption that they induced both an active tonic force, by changing the duction force vectors, and an increase in passive elastic forces, because of the longer route of the transposed muscles. However, these surgical techniques were later found to have several drawbacks, namely, residual duction deficiency, recurrence of the deviation, and need for further muscle surgery, mainly of the ipsilateral or contralateral antagonist rectus muscle.5–9 Originally received: June 21, 2004. Accepted: December 21, 2004. Manuscript no. 240482. 1 Pediatric Ophthalmology Unit, Schneider Children’s Medical Center of Israel, Tel Aviv, Israel. 2 Department of Ophthalmology, Rabin Medical Center, Beilinson Campus, Petah Tiqva and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. The authors have no financial support or interest in the article. Correspondence to M. Snir, MD, Pediatric Ophthalmology Unit, Schneider Children’s Medical Center of Israel, Petah Tiqva 49202, Israel. E-mail: [email protected]. © 2005 by the American Academy of Ophthalmology Published by Elsevier Inc.
In 1997, Foster10 modified the full vertical rectus muscle transposition procedure to the lateral rectus (LR) muscle for the treatment of sixth nerve palsy or Duane’s retraction syndrome types 1 and 2 by adding lateral posterior fixation sutures to transfix the transposed muscles to the sclera adjacent to the LR muscle at the equator. Closing the gap between the transposed vertical rectus muscles and the paralyzed LR muscle increased both the mechanical effects and the tonic abducting forces of the transposed vertical recti without changing adduction. The purpose of this study was to evaluate the surgical and functional results of full tendon rectus muscle transposition to the medial rectus (MR) muscle combined with posterior medial fixation sutures in patients with adduction deficiency (ADD) and Duane’s syndrome type 2.
Patients and Methods The cohort consisted of 12 consecutive patients (6 female, 6 male) with ADD caused by neurologic injury (motor vehicle accident) or Duane’s syndrome type 2. Six were treated from July 2001 to December 2003 (control group) by standard transposition of verISSN 0161-6420/05/$–see front matter doi:10.1016/j.ophtha.2004.12.032
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Figure 1. A, Standard vertical rectus muscle transposition to the medial rectus insertion. MR ⫽ medial rectus; SR ⫽ superior rectus; IR ⫽ inferior rectus. B, Combined vertical rectus muscle transposition to the medial rectus (MR) muscle insertion with medial posterior fixation sutures (the sideways V-like shape) placed 8 mm behind the MR muscle insertion at the upper and lower sides. The procedure changes the duction force vectors.
tical rectus muscles to the MR muscle and 6 from July 2001 to December 2003 by the augmented transposition technique (study group). All were operated on under general anesthesia by the same surgeon (MS). Patients with previous superior, inferior, or lateral recti muscle surgery, double dissociated vertical deviation, or ocular pathology were excluded from the study, as were patients followed for less than 6 months postoperatively. All patients underwent full ophthalmic and orthoptic evaluation, preoperatively and postoperatively, including cycloplegic refraction with 2 instillations (10 minutes apart) of cyclopentolate 1%. Distance (6 m) and near (0.33 m) deviation in the primary position was measured by the alternate prism cover test on an accommodative target in all 9 diagnostic positions of gaze with normal head posture and with the best optical correction, if necessary. Binocular tests for fusion (Worth 4-dots) and stereopsis (Titmus-fly test) were performed in the primary position. A thorough neurologic examination was done to exclude any neurologic dysfunction from myasthenia gravis or a spaceoccupying lesion. Duction dysfunction was evaluated by measuring the voluntary and forced ocular motility toward the paralyzed muscle. The results were rated on a 6-point scale as follows: full adduction of the affected eye ⫽ 0, mild limitation of adduction ⫽ ⫺1, moderate limitation of adduction ⫽ ⫺2, severe limitation of adduction up to the midline ⫽ ⫺3, very severe limitation of adduction before the midline ⫽ ⫺4, and no adduction of the affected eye ⫽ ⫺5. Forced duction test in adduction was performed intraoperatively. The indications for the augmented surgical procedure were horizontal misalignment for distance and near vision of ⱖ8 prism diopters (PD), adduction deficit of ⱖ⫺2, and significant abnormal head posture. Our goal was to correct the motor misalignment and functional deficiency while operating on the minimal number of extraocular muscles (EOMs). Institutional review board approval was not necessary.
Surgical Technique The augmented and standard vertical rectus muscle transposition procedures are presented in Figure 1. The surgical procedure was performed on the MR muscle and was adapted from that described by Foster10 for the LR muscle. A vertical, 180° limbal conjunctival peritomy was done, and each vertical rectus muscle was transposed toward the respective side of the insertion of the paralyzed MR muscle and then reattached to the sclera with Vicryl 6-0 sutures (Ethicon, Somerville, NJ).
940
Because the distance of the new insertion from the limbus to the temporal border of the transposed muscle was equivalent to the original insertion, the spiral of Tillaux was maintained. In the augmented transposition, a nonabsorbable 5-0 polyester (Dacron) suture (Ethicon) was placed in the sclera 8.0 mm posterior to the insertion of the paralyzed EOM, near the upper and lower borders, fixing 25% of the belly of each transposed muscle adjacent to the paralyzed MR muscle. This effectively closed the gap between the transposed vertical rectus muscle and the paralyzed MR muscle. The overlying conjunctiva was closed with interrupted 8-0 Vicryl sutures that were buried under the conjunctiva facing the sclera. On repeated forced duction test performed after transposition, none of the patients had limited abduction. The surgical and functional results were evaluated on day 1, and at 1, 3, 6, and 12 months postoperatively. Criteria for successful outcome were reduction of the horizontal deviation to ⱕ8 PD, improvement of duction deficiency to ⱕ⫺1, and improvement of binocular function.
Statistical Analysis The nonparametric Mann–Whitney test was used to compare groups for background data, age at diagnosis, duration of postoperative follow-up, ocular misalignment at distance and near vision, and limitation of EOM duction preoperatively and postoperatively. The Wilcoxon matched-pairs signed-ranks test was used to analyze the intragroup ocular deviation for distance and near vision, EOM duction limitation, and stereopsis preoperatively and postoperatively. A P value of ⱕ0.05 was considered significant. All statistical calculations were done with the Statistical Package for Social Sciences.11
Results Mean age at diagnosis in the study and control groups was, respectively, 30.5⫾8.4 years (range, 18 – 42 years) and 22.2⫾9.6 years (range, 9 –31 years); corresponding age at surgery was 33.5⫾8.2 years (range, 16 –39 years) and 24.5⫾10.0 years (range, 10 –38 years). There were no significant between-group differences in either of these parameters (P ⫽ 0.13, P ⫽ 0.11, respectively). Two patients in the study group (33.3%) and 3 (50%) in the control group had undergone previous EOM surgery (P ⫽ 0.56). Four patients in each group had Duane’s syndrome type 2, and 2
Snir et al 䡠 Augmented Medial Transposition of Vertical Recti Muscles Table 1. Preoperative and Postoperative Parameters (Range and Mean ⫾ Standard Deviation) in Patients with Adduction Deficiency Preoperative Results Ocular deviation (Prism Diopters) Group
Distance
Study (n ⫽ 6)
Near
Deficiency in Adduction
21.5 ⫾ 5.13 22.5 ⫾ 3.51 ⫺3.67 ⫾ 0.52 (16–30) (16–30) (⫺3 to ⫺4) Control (n ⫽ 6) 23.83 ⫾ 3.5 22.0 ⫾ 4.2 ⫺3.83 ⫾ 0.41 (18–28) (18–30) (⫺3 to ⫺4) Between group NS NS NS comparison
Postoperative Results Binocular Functions Fusion
Stereopsis
0
0
0
0
NS
NS
Ocular Deviation (Prism Diopters) Distance
Near
Deficiency in Adduction
Binocular Functions Fusion
Stereopsis
5.50 ⫾ 3.67 5.83 ⫾ 4.4 ⫺1.0 ⫾ 0.63 5/6 (83.3%) 5/6 (83.3%) (1–12) (1–14) (0 to ⫺2) 400“–3000” 13.33 ⫾ 2.07 13.0 ⫾ 3.29 ⫺2.0 ⫾ 0.63 0 0 (10–16) (10–18) (⫺1 to ⫺3) P ⫽ 0.007 P ⫽ 0.02 P ⫽ 0.025 P ⫽ 0.07 P ⫽ 0.02
NS ⫽ not significant.
patients in each group were post motor vehicle accident. The mean duration of postoperative follow-up was 22.2⫾5.8 months (range, 14 –29 months) and 53.3⫾6.3 months (range, 45– 60 months), respectively. As expected, it was significantly longer in the control patients (P ⫽ 0.004), who were operated on before July 2001, when the augmented procedure was introduced. No significant upshoots or downshoots in adduction were noted in any of the patients. The preoperative and postoperative values of the 4 outcome measures, namely, ocular misalignment, duction, binocular function, (and reoperation) for the 2 groups are presented in Table 1.
Ocular Misalignment In the study patients with ADD, mean distance and near misalignment decreased postoperatively in 74.5% and 74%, respectively (P ⫽ 0.03, P ⫽ 0.03). Before surgery, 4 patients (66.6%) had a distance horizontal misalignment of ⱖ20 PD, and 5 (83.3%) had a near horizontal misalignment of ⱖ20 PD. After surgery, 5 of the 6 patients (83.3%) had residual exotropia of ⬍6 PD at distance and near, and only 1 patient (16.6%) had significant residual exodeviation for distance (12 PD) and near (14 PD). In the control group, mean distance and near deviations in patients with ADD decreased after surgery in 60% and 59%, respectively (P ⫽ 0.03, P ⫽ 0.03). Five patients (83.3%) had a mean preoperative distance and near exotropia of ⱖ20 PD, and all patients had a mean postoperative residual distance and near exotropia of ⬎8 PD (range, 12–18 PD).
Duction In the study group, mean deficiency in adduction improved in 73% (P ⫽ 0.02). In addition, all patients had deficiency in adduction of ⫺3 to ⫺4 before surgery compared with only 1 patient (16.6%) with a residual ADD of ⫺2 after surgery. This patient refused reoperation. In the control group, mean ADD improved in 52% (3 patients) (P ⫽ 0.02). All 6 patients had deficiency of adduction of ⫺3 to ⫺4 before surgery, and 5 patients (83.3%) had a residual deficiency of ⫺2 to ⫺3 after surgery.
Binocular Function In the study group, fusion and stereopsis examinations after surgery showed sensory functioning in 5 of the 6 patients (83.3%), with a stereopsis range of 400” to 3000” of arc compared with none before surgery. However, in the control group, fusion and stereopsis tests showed no sensory function either before or after surgery.
Reoperation In the study group, 1 of the 6 patients needed reoperation, but he refused to undergo surgery, whereas in the control group reoperation was warranted in 5 of 6 patients. No surgical complications, underaction of supraduction and infraduction, or abduction deficiencies were noted during follow-up in either group. No enophthalmos on adduction was exacerbated by the surgery in either group. Between-group comparison revealed significantly better postoperative results in the study group for all 3 parameters: distance and near exodeviation, P ⫽ 0.007 and P ⫽ 0.02, respectively; adduction deficit, P ⫽ 0.025, and fusion and stereopsis, P ⫽ 0.02 and P ⫽ 0.02, respectively.
Discussion This study shows that in patients with ADD and Duane’s syndrome type 2, the augmented reverse Hummelsheim procedure yields significantly better results than the standard procedure. Earlier studies reported that large LR recession for the treatment of ADD and Duane’s syndrome type 2 improves abnormal compensatory head position and face turn but has a limited effect only on aligning the eyes in the primary position.12 Kubota et al13 suggested the use of 2 graduated recessions of the LR muscle for exotropic Duane’s syndrome and of the MR muscle for esotropic Duane’s syndrome. The success rate was 89%, with a residual deviation of 7° in the primary position and improved abnormal head posture. Pressman and Scott,12 applied the same procedure in 2 patients (14.3%) with Duane’s syndrome type 2 and noted the presence of orthophoria in the primary position postoperatively, without abnormal head turn and retraction. They suggested that the recession procedure had decreased ocular motility in all fields of action of the operated muscle. Kraft14 recommended 1 large LR recession in patients with exotropia of ⬍24° PD and bilateral LR recession for patients with exotropia of ⬎25° PD. In addition, he recommended searching for a fibrotic scleral band in cases of a positive forced duction test at the end of the operation. Transposition procedures are used to overcome abduction or adduction deficiency, thereby improving both ocular alignment in the primary position and head posture. The
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Ophthalmology Volume 112, Number 5, May 2005 standard transposition procedure of a full vertical rectus muscle1,4,9 is useful for patients with moderate exodeviation and a face turn of ⬍20°. Because the mechanical action of the EOMs is determined by the distance between their functional origin and their insertion on the eye globe, in patients with muscle palsy, changing the direction of the EOMs may generate mechanical vector forces that replace the absent ones,15 thereby inducing active adduction forces that enlarge the area of single binocular vision. This yields a better mechanical effect if no restriction is present and prevents multiple EOM surgery in cases of paralytic strabismus.2,3,5,16 However, the introduction of magnetic resonance imaging to evaluate outcome demonstrated only minimal lateralization of the transposed vertical rectus muscles because of the “pulley effect” of the EOM, which allowed only the anterior section of the muscles to move despite large transpositions.14,17 Another disadvantage of the procedure is its induction of vertical deviations, which require further surgical procedures.7 To overcome the pulley effect, Foster10 and Clark et al18,19 applied posterior fixation sutures on the transposed muscle. This increased both the tonic forces generated by the muscles and the mechanical effect of the transposition, because the force vectors were more aligned with the palsied muscle. In addition, it increased the rotational force in adduction, without the need to recess the antagonist muscle. The advantages of this modification were confirmed by magnetic resonance imaging scans, which showed that a larger portion of the transposed EOM shifted to a new position compared with the standard technique. Paysse et al20 described an augmented full-tendon transposition of the vertical rectus muscles to the MR muscle insertion in 1 patient with partial third-nerve palsy. They noted a significant reduction in distance and near exodeviation from 60 to 70 PD preoperatively to 10 PD of intermittent exotropia at distance and 10 to 20 PD exotropia at near postoperatively. Foster10 used the same technique in a patient with right gaze palsy. He transposed the vertical muscles toward the MR insertion in 1 eye and toward the LR muscle in the other eye. This resulted in a significant improvement in adduction and abduction, no face turn, and cancellation of the esotropia/exotropia. In this study, we used a medial vertical rectus muscle transposition technique in patients with ADD and Duane’s syndrome type 2, applying the same modification reported by Foster10 for LR muscle transposition in Duane’s syndrome type 1. All patients in the study had some MR function preoperatively, and the eye could adduct up to or past the midline. Postoperatively, we observed a significant decrease in distance and near deviation, improved MR adduction, and improved binocular function. The procedure apparently enhanced the vector force of the MR muscle and adduction motility without weakening abduction. It also avoided the need to recess the antagonist (LR) muscle. On comparison of the outcome with the standard medial vertical rectus muscle transposition, the new technique was found to have 4 specific advantages: (1) higher rate of reduction in distance and near exotropic deviation (74.5% and 79% of patients, respectively, vs. 56% and 59%, in the control group; P ⫽ 0.0007; P ⫽ 0.02); (2) higher rate of improvement in mean adduction (73% of patients vs. 52%
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in control group; P ⫽ 0.025); (3) higher rate of fusion and stereopsis (83% of patients vs. zero in control group; P ⫽ 0.02; P ⫽ 0.02); and (4) lesser need for reoperation (16.0% vs. 100% in control group). Neither anterior segment ischemia nor vertical or horizontal underaction was found after the augmented procedure. Murdock and Kushner21 reported on 1 patient with anterior segment ischemia after augmented lateral vertical muscle transposition. They suggested that the underlying mechanism was either a procedure-induced impairment of the blood supply from the LR muscle or disruption of the posterior ciliary artery blood flow by the lateral fixation sutures. Vertical deviation after augmented vertical rectus muscle transposition to the LR muscle was reported in 2 of 32 patients (6%) by Velez et al22 and 4 of 21 (19%) by Foster.10 In conclusion, combined medial vertical rectus muscle transposition with medial posterior fixation sutures is recommended for patients with ADD or Duane’s syndrome type 2. It significantly decreases the distance and near misalignment, as well as the limited adduction. Binocular function is achieved by most patients, and the reoperation rate is low. In our series, there were no early or late complications. Overall, we obtained better anatomic and functional results than the standard procedure, with less EOM manipulation.
References 1. Ronne G. Hummelsheim’s operation: technique and results. Acta Ophthalmol (Copenh) 1954;2:633– 8. 2. Rosenbaum AL, Foster RS, Ballard E, et al. Complete superior and inferior rectus transposition with adjustable medial rectus recession for abducens palsy. Strabismus 1984;2:599 – 605. 3. Rosenbaum AL, Kushner BJ, Kirschen D. Vertical rectus muscle transposition and botulinum toxin (Oculinum) to medial rectus for abducens palsy. Arch Ophthalmol 1989;107:820 –3. 4. Brooks SE, Olitsky SE, deB Ribeiro G. Augmented Hummelsheim procedure for paralytic strabismus. J Pediatr Ophthalmol Strabismus 2000;37:189 –95. 5. Molarte AB, Rosenbaum AL. Vertical rectus muscle transposition surgery for Duane’s syndrome. J Pediatr Ophthalmol Strabismus 1990;27:171–7. 6. Wybar KC. Management of sixth nerve palsy and Duane’s retraction syndrome. Trans Ophthalmol Soc U K 1981;101:276 – 8. 7. Laby DM, Rosenbaum AL. Adjustable vertical rectus muscle transposition surgery. J Pediatr Ophthalmol Strabismus 1994;31:75–8. 8. O’Connor R. Tendon transplantation in ocular-muscle paralysis. Am J Ophthalmol 1935;18:813–20. 9. Uribe LE. Muscle transplantation in ocular paralysis. Am J Ophthalmol 1968;65:600 –7. 10. Foster RS. Vertical muscle transposition augmented with lateral fixation. J AAPOS 1997;1:20 –30. 11. SPSS [computer program]. Release 11.5. Chicago: Professional Statistics; 2003. 12. Pressman SH, Scott WE. Surgical treatment of Duane’s syndrome. Ophthalmology 1986;93:29 –38. 13. Kubota N, Takahashi H, Hayashi T, et al. Outcome of surgery in 124 cases of Duane’s retraction syndrome (DRS) treated by intraoperatively graduated recession of the medial rectus for esotropic DRS, and of the lateral rectus for exotropic DRS. Binocul Vis Strabismus Q 2001;16:15–22.
Snir et al 䡠 Augmented Medial Transposition of Vertical Recti Muscles 14. Kraft SP. A surgical approach for Duane syndrome. J Pediatr Ophthalmol Strabismus 1988;25:119 –30. 15. Clark RA, Miller JM, Demer JL. Location and stability of rectus muscle pulleys: muscle paths as a function of gaze. Invest Ophthalmol Vis Sci 1997;38:227– 40. 16. Metz HS. 20th annual Frank Costenbader Lecture: muscle transposition surgery. J Pediatr Ophthalmol Strabismus 1993; 30:346 –53. 17. Miller JM, Demer JL, Rosenbaum AL. Effect of transposition surgery on rectus muscle paths by magnetic resonance imaging. Ophthalmology 1993;100:475– 87. 18. Clark RA, Isenberg SJ, Rosenbaum AL, Demer JL. Posterior fixation sutures: a revised mechanical explanation for the
19. 20. 21. 22.
Faden operation based on rectus extraocular muscle pulleys. Am J Ophthalmol 1999;128:702–14. Clark RA, Demer JL. Rectus extraocular muscle pulley displacement after surgical transposition and posterior fixation for treatment of paralytic strabismus. Am J Ophthalmol 2002;133:119–28. Paysse EA, Brady McCreery KM, Ross A, Coats DK. Use of augmented rectus muscle transposition surgery for complex strabismus. Ophthalmology 2002;109:1309 –14. Murdock TJ, Kushner BJ. Anterior segment ischemia after surgery on 2 vertical rectus muscles augmented with lateral fixation sutures. J AAPOS 2001;5:323–24. Velez FG, Foster RS, Rosenbaum AL. Vertical rectus muscle augmented transposition in Duane syndrome. J AAPOS 2001;5:105–13.
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Partial or full tendon transposition procedures1– 8 were introduced for the treatment of complex ocular motility abnormalities on the assumption that they induced both an active tonic force, by changing the duction force vectors, and an increase in passive elastic forces, because of the longer route of the transposed muscles. However, these surgical techniques were later found to have several drawbacks, namely, residual duction deficiency, recurrence of the deviation, and need for further muscle surgery, mainly of the ipsilateral or contralateral antagonist rectus muscle.5–9 Originally received: June 21, 2004. Accepted: December 21, 2004. Manuscript no. 240482. 1 Pediatric Ophthalmology Unit, Schneider Children’s Medical Center of Israel, Tel Aviv, Israel. 2 Department of Ophthalmology, Rabin Medical Center, Beilinson Campus, Petah Tiqva and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. The authors have no financial support or interest in the article. Correspondence to M. Snir, MD, Pediatric Ophthalmology Unit, Schneider Children’s Medical Center of Israel, Petah Tiqva 49202, Israel. E-mail: [email protected]. © 2005 by the American Academy of Ophthalmology Published by Elsevier Inc.
In 1997, Foster10 modified the full vertical rectus muscle transposition procedure to the lateral rectus (LR) muscle for the treatment of sixth nerve palsy or Duane’s retraction syndrome types 1 and 2 by adding lateral posterior fixation sutures to transfix the transposed muscles to the sclera adjacent to the LR muscle at the equator. Closing the gap between the transposed vertical rectus muscles and the paralyzed LR muscle increased both the mechanical effects and the tonic abducting forces of the transposed vertical recti without changing adduction. The purpose of this study was to evaluate the surgical and functional results of full tendon rectus muscle transposition to the medial rectus (MR) muscle combined with posterior medial fixation sutures in patients with adduction deficiency (ADD) and Duane’s syndrome type 2.
Patients and Methods The cohort consisted of 12 consecutive patients (6 female, 6 male) with ADD caused by neurologic injury (motor vehicle accident) or Duane’s syndrome type 2. Six were treated from July 2001 to December 2003 (control group) by standard transposition of verISSN 0161-6420/05/$–see front matter doi:10.1016/j.ophtha.2004.12.032
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Ophthalmology Volume 112, Number 5, May 2005
Figure 1. A, Standard vertical rectus muscle transposition to the medial rectus insertion. MR ⫽ medial rectus; SR ⫽ superior rectus; IR ⫽ inferior rectus. B, Combined vertical rectus muscle transposition to the medial rectus (MR) muscle insertion with medial posterior fixation sutures (the sideways V-like shape) placed 8 mm behind the MR muscle insertion at the upper and lower sides. The procedure changes the duction force vectors.
tical rectus muscles to the MR muscle and 6 from July 2001 to December 2003 by the augmented transposition technique (study group). All were operated on under general anesthesia by the same surgeon (MS). Patients with previous superior, inferior, or lateral recti muscle surgery, double dissociated vertical deviation, or ocular pathology were excluded from the study, as were patients followed for less than 6 months postoperatively. All patients underwent full ophthalmic and orthoptic evaluation, preoperatively and postoperatively, including cycloplegic refraction with 2 instillations (10 minutes apart) of cyclopentolate 1%. Distance (6 m) and near (0.33 m) deviation in the primary position was measured by the alternate prism cover test on an accommodative target in all 9 diagnostic positions of gaze with normal head posture and with the best optical correction, if necessary. Binocular tests for fusion (Worth 4-dots) and stereopsis (Titmus-fly test) were performed in the primary position. A thorough neurologic examination was done to exclude any neurologic dysfunction from myasthenia gravis or a spaceoccupying lesion. Duction dysfunction was evaluated by measuring the voluntary and forced ocular motility toward the paralyzed muscle. The results were rated on a 6-point scale as follows: full adduction of the affected eye ⫽ 0, mild limitation of adduction ⫽ ⫺1, moderate limitation of adduction ⫽ ⫺2, severe limitation of adduction up to the midline ⫽ ⫺3, very severe limitation of adduction before the midline ⫽ ⫺4, and no adduction of the affected eye ⫽ ⫺5. Forced duction test in adduction was performed intraoperatively. The indications for the augmented surgical procedure were horizontal misalignment for distance and near vision of ⱖ8 prism diopters (PD), adduction deficit of ⱖ⫺2, and significant abnormal head posture. Our goal was to correct the motor misalignment and functional deficiency while operating on the minimal number of extraocular muscles (EOMs). Institutional review board approval was not necessary.
Surgical Technique The augmented and standard vertical rectus muscle transposition procedures are presented in Figure 1. The surgical procedure was performed on the MR muscle and was adapted from that described by Foster10 for the LR muscle. A vertical, 180° limbal conjunctival peritomy was done, and each vertical rectus muscle was transposed toward the respective side of the insertion of the paralyzed MR muscle and then reattached to the sclera with Vicryl 6-0 sutures (Ethicon, Somerville, NJ).
940
Because the distance of the new insertion from the limbus to the temporal border of the transposed muscle was equivalent to the original insertion, the spiral of Tillaux was maintained. In the augmented transposition, a nonabsorbable 5-0 polyester (Dacron) suture (Ethicon) was placed in the sclera 8.0 mm posterior to the insertion of the paralyzed EOM, near the upper and lower borders, fixing 25% of the belly of each transposed muscle adjacent to the paralyzed MR muscle. This effectively closed the gap between the transposed vertical rectus muscle and the paralyzed MR muscle. The overlying conjunctiva was closed with interrupted 8-0 Vicryl sutures that were buried under the conjunctiva facing the sclera. On repeated forced duction test performed after transposition, none of the patients had limited abduction. The surgical and functional results were evaluated on day 1, and at 1, 3, 6, and 12 months postoperatively. Criteria for successful outcome were reduction of the horizontal deviation to ⱕ8 PD, improvement of duction deficiency to ⱕ⫺1, and improvement of binocular function.
Statistical Analysis The nonparametric Mann–Whitney test was used to compare groups for background data, age at diagnosis, duration of postoperative follow-up, ocular misalignment at distance and near vision, and limitation of EOM duction preoperatively and postoperatively. The Wilcoxon matched-pairs signed-ranks test was used to analyze the intragroup ocular deviation for distance and near vision, EOM duction limitation, and stereopsis preoperatively and postoperatively. A P value of ⱕ0.05 was considered significant. All statistical calculations were done with the Statistical Package for Social Sciences.11
Results Mean age at diagnosis in the study and control groups was, respectively, 30.5⫾8.4 years (range, 18 – 42 years) and 22.2⫾9.6 years (range, 9 –31 years); corresponding age at surgery was 33.5⫾8.2 years (range, 16 –39 years) and 24.5⫾10.0 years (range, 10 –38 years). There were no significant between-group differences in either of these parameters (P ⫽ 0.13, P ⫽ 0.11, respectively). Two patients in the study group (33.3%) and 3 (50%) in the control group had undergone previous EOM surgery (P ⫽ 0.56). Four patients in each group had Duane’s syndrome type 2, and 2
Snir et al 䡠 Augmented Medial Transposition of Vertical Recti Muscles Table 1. Preoperative and Postoperative Parameters (Range and Mean ⫾ Standard Deviation) in Patients with Adduction Deficiency Preoperative Results Ocular deviation (Prism Diopters) Group
Distance
Study (n ⫽ 6)
Near
Deficiency in Adduction
21.5 ⫾ 5.13 22.5 ⫾ 3.51 ⫺3.67 ⫾ 0.52 (16–30) (16–30) (⫺3 to ⫺4) Control (n ⫽ 6) 23.83 ⫾ 3.5 22.0 ⫾ 4.2 ⫺3.83 ⫾ 0.41 (18–28) (18–30) (⫺3 to ⫺4) Between group NS NS NS comparison
Postoperative Results Binocular Functions Fusion
Stereopsis
0
0
0
0
NS
NS
Ocular Deviation (Prism Diopters) Distance
Near
Deficiency in Adduction
Binocular Functions Fusion
Stereopsis
5.50 ⫾ 3.67 5.83 ⫾ 4.4 ⫺1.0 ⫾ 0.63 5/6 (83.3%) 5/6 (83.3%) (1–12) (1–14) (0 to ⫺2) 400“–3000” 13.33 ⫾ 2.07 13.0 ⫾ 3.29 ⫺2.0 ⫾ 0.63 0 0 (10–16) (10–18) (⫺1 to ⫺3) P ⫽ 0.007 P ⫽ 0.02 P ⫽ 0.025 P ⫽ 0.07 P ⫽ 0.02
NS ⫽ not significant.
patients in each group were post motor vehicle accident. The mean duration of postoperative follow-up was 22.2⫾5.8 months (range, 14 –29 months) and 53.3⫾6.3 months (range, 45– 60 months), respectively. As expected, it was significantly longer in the control patients (P ⫽ 0.004), who were operated on before July 2001, when the augmented procedure was introduced. No significant upshoots or downshoots in adduction were noted in any of the patients. The preoperative and postoperative values of the 4 outcome measures, namely, ocular misalignment, duction, binocular function, (and reoperation) for the 2 groups are presented in Table 1.
Ocular Misalignment In the study patients with ADD, mean distance and near misalignment decreased postoperatively in 74.5% and 74%, respectively (P ⫽ 0.03, P ⫽ 0.03). Before surgery, 4 patients (66.6%) had a distance horizontal misalignment of ⱖ20 PD, and 5 (83.3%) had a near horizontal misalignment of ⱖ20 PD. After surgery, 5 of the 6 patients (83.3%) had residual exotropia of ⬍6 PD at distance and near, and only 1 patient (16.6%) had significant residual exodeviation for distance (12 PD) and near (14 PD). In the control group, mean distance and near deviations in patients with ADD decreased after surgery in 60% and 59%, respectively (P ⫽ 0.03, P ⫽ 0.03). Five patients (83.3%) had a mean preoperative distance and near exotropia of ⱖ20 PD, and all patients had a mean postoperative residual distance and near exotropia of ⬎8 PD (range, 12–18 PD).
Duction In the study group, mean deficiency in adduction improved in 73% (P ⫽ 0.02). In addition, all patients had deficiency in adduction of ⫺3 to ⫺4 before surgery compared with only 1 patient (16.6%) with a residual ADD of ⫺2 after surgery. This patient refused reoperation. In the control group, mean ADD improved in 52% (3 patients) (P ⫽ 0.02). All 6 patients had deficiency of adduction of ⫺3 to ⫺4 before surgery, and 5 patients (83.3%) had a residual deficiency of ⫺2 to ⫺3 after surgery.
Binocular Function In the study group, fusion and stereopsis examinations after surgery showed sensory functioning in 5 of the 6 patients (83.3%), with a stereopsis range of 400” to 3000” of arc compared with none before surgery. However, in the control group, fusion and stereopsis tests showed no sensory function either before or after surgery.
Reoperation In the study group, 1 of the 6 patients needed reoperation, but he refused to undergo surgery, whereas in the control group reoperation was warranted in 5 of 6 patients. No surgical complications, underaction of supraduction and infraduction, or abduction deficiencies were noted during follow-up in either group. No enophthalmos on adduction was exacerbated by the surgery in either group. Between-group comparison revealed significantly better postoperative results in the study group for all 3 parameters: distance and near exodeviation, P ⫽ 0.007 and P ⫽ 0.02, respectively; adduction deficit, P ⫽ 0.025, and fusion and stereopsis, P ⫽ 0.02 and P ⫽ 0.02, respectively.
Discussion This study shows that in patients with ADD and Duane’s syndrome type 2, the augmented reverse Hummelsheim procedure yields significantly better results than the standard procedure. Earlier studies reported that large LR recession for the treatment of ADD and Duane’s syndrome type 2 improves abnormal compensatory head position and face turn but has a limited effect only on aligning the eyes in the primary position.12 Kubota et al13 suggested the use of 2 graduated recessions of the LR muscle for exotropic Duane’s syndrome and of the MR muscle for esotropic Duane’s syndrome. The success rate was 89%, with a residual deviation of 7° in the primary position and improved abnormal head posture. Pressman and Scott,12 applied the same procedure in 2 patients (14.3%) with Duane’s syndrome type 2 and noted the presence of orthophoria in the primary position postoperatively, without abnormal head turn and retraction. They suggested that the recession procedure had decreased ocular motility in all fields of action of the operated muscle. Kraft14 recommended 1 large LR recession in patients with exotropia of ⬍24° PD and bilateral LR recession for patients with exotropia of ⬎25° PD. In addition, he recommended searching for a fibrotic scleral band in cases of a positive forced duction test at the end of the operation. Transposition procedures are used to overcome abduction or adduction deficiency, thereby improving both ocular alignment in the primary position and head posture. The
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Ophthalmology Volume 112, Number 5, May 2005 standard transposition procedure of a full vertical rectus muscle1,4,9 is useful for patients with moderate exodeviation and a face turn of ⬍20°. Because the mechanical action of the EOMs is determined by the distance between their functional origin and their insertion on the eye globe, in patients with muscle palsy, changing the direction of the EOMs may generate mechanical vector forces that replace the absent ones,15 thereby inducing active adduction forces that enlarge the area of single binocular vision. This yields a better mechanical effect if no restriction is present and prevents multiple EOM surgery in cases of paralytic strabismus.2,3,5,16 However, the introduction of magnetic resonance imaging to evaluate outcome demonstrated only minimal lateralization of the transposed vertical rectus muscles because of the “pulley effect” of the EOM, which allowed only the anterior section of the muscles to move despite large transpositions.14,17 Another disadvantage of the procedure is its induction of vertical deviations, which require further surgical procedures.7 To overcome the pulley effect, Foster10 and Clark et al18,19 applied posterior fixation sutures on the transposed muscle. This increased both the tonic forces generated by the muscles and the mechanical effect of the transposition, because the force vectors were more aligned with the palsied muscle. In addition, it increased the rotational force in adduction, without the need to recess the antagonist muscle. The advantages of this modification were confirmed by magnetic resonance imaging scans, which showed that a larger portion of the transposed EOM shifted to a new position compared with the standard technique. Paysse et al20 described an augmented full-tendon transposition of the vertical rectus muscles to the MR muscle insertion in 1 patient with partial third-nerve palsy. They noted a significant reduction in distance and near exodeviation from 60 to 70 PD preoperatively to 10 PD of intermittent exotropia at distance and 10 to 20 PD exotropia at near postoperatively. Foster10 used the same technique in a patient with right gaze palsy. He transposed the vertical muscles toward the MR insertion in 1 eye and toward the LR muscle in the other eye. This resulted in a significant improvement in adduction and abduction, no face turn, and cancellation of the esotropia/exotropia. In this study, we used a medial vertical rectus muscle transposition technique in patients with ADD and Duane’s syndrome type 2, applying the same modification reported by Foster10 for LR muscle transposition in Duane’s syndrome type 1. All patients in the study had some MR function preoperatively, and the eye could adduct up to or past the midline. Postoperatively, we observed a significant decrease in distance and near deviation, improved MR adduction, and improved binocular function. The procedure apparently enhanced the vector force of the MR muscle and adduction motility without weakening abduction. It also avoided the need to recess the antagonist (LR) muscle. On comparison of the outcome with the standard medial vertical rectus muscle transposition, the new technique was found to have 4 specific advantages: (1) higher rate of reduction in distance and near exotropic deviation (74.5% and 79% of patients, respectively, vs. 56% and 59%, in the control group; P ⫽ 0.0007; P ⫽ 0.02); (2) higher rate of improvement in mean adduction (73% of patients vs. 52%
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in control group; P ⫽ 0.025); (3) higher rate of fusion and stereopsis (83% of patients vs. zero in control group; P ⫽ 0.02; P ⫽ 0.02); and (4) lesser need for reoperation (16.0% vs. 100% in control group). Neither anterior segment ischemia nor vertical or horizontal underaction was found after the augmented procedure. Murdock and Kushner21 reported on 1 patient with anterior segment ischemia after augmented lateral vertical muscle transposition. They suggested that the underlying mechanism was either a procedure-induced impairment of the blood supply from the LR muscle or disruption of the posterior ciliary artery blood flow by the lateral fixation sutures. Vertical deviation after augmented vertical rectus muscle transposition to the LR muscle was reported in 2 of 32 patients (6%) by Velez et al22 and 4 of 21 (19%) by Foster.10 In conclusion, combined medial vertical rectus muscle transposition with medial posterior fixation sutures is recommended for patients with ADD or Duane’s syndrome type 2. It significantly decreases the distance and near misalignment, as well as the limited adduction. Binocular function is achieved by most patients, and the reoperation rate is low. In our series, there were no early or late complications. Overall, we obtained better anatomic and functional results than the standard procedure, with less EOM manipulation.
References 1. Ronne G. Hummelsheim’s operation: technique and results. Acta Ophthalmol (Copenh) 1954;2:633– 8. 2. Rosenbaum AL, Foster RS, Ballard E, et al. Complete superior and inferior rectus transposition with adjustable medial rectus recession for abducens palsy. Strabismus 1984;2:599 – 605. 3. Rosenbaum AL, Kushner BJ, Kirschen D. Vertical rectus muscle transposition and botulinum toxin (Oculinum) to medial rectus for abducens palsy. Arch Ophthalmol 1989;107:820 –3. 4. Brooks SE, Olitsky SE, deB Ribeiro G. Augmented Hummelsheim procedure for paralytic strabismus. J Pediatr Ophthalmol Strabismus 2000;37:189 –95. 5. Molarte AB, Rosenbaum AL. Vertical rectus muscle transposition surgery for Duane’s syndrome. J Pediatr Ophthalmol Strabismus 1990;27:171–7. 6. Wybar KC. Management of sixth nerve palsy and Duane’s retraction syndrome. Trans Ophthalmol Soc U K 1981;101:276 – 8. 7. Laby DM, Rosenbaum AL. Adjustable vertical rectus muscle transposition surgery. J Pediatr Ophthalmol Strabismus 1994;31:75–8. 8. O’Connor R. Tendon transplantation in ocular-muscle paralysis. Am J Ophthalmol 1935;18:813–20. 9. Uribe LE. Muscle transplantation in ocular paralysis. Am J Ophthalmol 1968;65:600 –7. 10. Foster RS. Vertical muscle transposition augmented with lateral fixation. J AAPOS 1997;1:20 –30. 11. SPSS [computer program]. Release 11.5. Chicago: Professional Statistics; 2003. 12. Pressman SH, Scott WE. Surgical treatment of Duane’s syndrome. Ophthalmology 1986;93:29 –38. 13. Kubota N, Takahashi H, Hayashi T, et al. Outcome of surgery in 124 cases of Duane’s retraction syndrome (DRS) treated by intraoperatively graduated recession of the medial rectus for esotropic DRS, and of the lateral rectus for exotropic DRS. Binocul Vis Strabismus Q 2001;16:15–22.
Snir et al 䡠 Augmented Medial Transposition of Vertical Recti Muscles 14. Kraft SP. A surgical approach for Duane syndrome. J Pediatr Ophthalmol Strabismus 1988;25:119 –30. 15. Clark RA, Miller JM, Demer JL. Location and stability of rectus muscle pulleys: muscle paths as a function of gaze. Invest Ophthalmol Vis Sci 1997;38:227– 40. 16. Metz HS. 20th annual Frank Costenbader Lecture: muscle transposition surgery. J Pediatr Ophthalmol Strabismus 1993; 30:346 –53. 17. Miller JM, Demer JL, Rosenbaum AL. Effect of transposition surgery on rectus muscle paths by magnetic resonance imaging. Ophthalmology 1993;100:475– 87. 18. Clark RA, Isenberg SJ, Rosenbaum AL, Demer JL. Posterior fixation sutures: a revised mechanical explanation for the
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Faden operation based on rectus extraocular muscle pulleys. Am J Ophthalmol 1999;128:702–14. Clark RA, Demer JL. Rectus extraocular muscle pulley displacement after surgical transposition and posterior fixation for treatment of paralytic strabismus. Am J Ophthalmol 2002;133:119–28. Paysse EA, Brady McCreery KM, Ross A, Coats DK. Use of augmented rectus muscle transposition surgery for complex strabismus. Ophthalmology 2002;109:1309 –14. Murdock TJ, Kushner BJ. Anterior segment ischemia after surgery on 2 vertical rectus muscles augmented with lateral fixation sutures. J AAPOS 2001;5:323–24. Velez FG, Foster RS, Rosenbaum AL. Vertical rectus muscle augmented transposition in Duane syndrome. J AAPOS 2001;5:105–13.
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