Horizontal Transposition of the Vertical Rectus Muscles for Cyclotropia

GUNTER K. VON NOORDEN, MD., RACHAEL H. JENKINS, D.B.O., CO., AND MILTON W. CHU, M.D.

• PURPOSE: We studied the effect of horizontal don. It becomes the procedure of choice when transposition of the vertical rectus muscles on surgery on the superior oblique tendon is preclud­ incyclotropia and excyclotropia in terms of the ed, either by the tendon's congenital absence or by amount of correction obtained and the stability of previous surgery on the tendon. Nasal transposi­ the outcome. tion of the superior rectus muscle or temporal • METHOD: Preoperative measurements for cyclo­ transposition of the inferior rectus muscle is ideally tropia were compared in 11 patients with measure­ suited for incyclotropia. No comparably effective ments during the immediate postoperative period operation exists. and last follow-up. Excyclotropia was treated with nasal transposition of the inferior rectus muscle E DEFINE CYCLOTROPIA AS A MANIFEST DE- and incyclotropia with nasal transposition of the viation of one or both eyes around the superior rectus muscle, to which we added tempor­ anteroposterior axis of the globe or al transposition to the inferior rectus muscle in globes. This condition occurs frequently in cycloverti­ one patient to enhance the effect. cal strabismus and usually accompanies any dysfunc­ • RESULTS: Fusion in all gaze positions was re­ tion of one of the oblique muscles. Unless the stored in six patients and functional improvement cyclotropia is of recent onset,1 patients are rarely occurred in five. The average effect of horizontal aware of image torsion because the ocular misalign­ transposition of one vertical rectus muscle for ment is kept latent by cyclofusion or because sensory cyclotropia was a correction of 7 degrees in pri­ or psychological adaptive mechanisms2,3 have devel­ mary position and of 11 degrees in depression. oped. However, once a patient becomes aware of This effect remained stable after a mean follow-up torsional diplopia, the symptoms are rarely tolerated of 17 months, and additional improvement oc­ and surgery is usually indicated. Several approaches curred in one patient. One patient developed a are available. Anterior and lateral displacement of the hypertropia, eliminated by an additional opera­ anterior portion of the superior oblique tendon, tion, in the treated eye. according to Harada and Ito,4 has become an accept­ • CONCLUSIONS: For excyclotropia, nasal trans­ ed mode of treatment for excyclotropia, although this operation cannot be performed when the superior position of the inferior rectus muscle is a viable oblique muscle is congenitally absent or when its alternative to lateral and anterior transposition of tendon has been previously cut. Moreover, no surgical the anterior portion of the superior oblique ten- technique exists for treating incyclotropia that can be performed with equal facility on the inferior oblique Accepted for publication March 4, 1996. muscle. From the Cullen Eye Institute, Baylor College of Medicine, Houston, Texas; and the Ophthalmology Service, Texas Children's Hospital, We have shown that horizontal transposition of Houston, Texas (Dr. von Noorden and Ms. Jenkins). Dr. Chu is in the vertical rectus muscles5 reduces cyclotropia and private practice in Camarillo, California. Reprint requests to Rachael H. Jenkins, CO., Ophthalmology Serv­ that artificial cyclorotation of the eyes created by this ice, Texas Children's Hospital, MC-3-2700, Houston, TX 77030; fax: method benefits patients with congenital nystagmus (713) 796-8110.

VOL.122, NO. 3 © AMERICAN JOURNAL OF OPHTHALMOLOGY 1996;122:325-330 325 who have a compensatory head tilt to one shoulder.6 eye while the patient looked at a fixation light held at However, no data are available on the stability of the a 33-cm fixation distance in primary position and a surgical result or on the quantitative effect of this 20-degree depression. A 10-prism diopter prism was operation for cyclotropia. We address these points in inserted base down behind the red Maddox rod to this article and report a complication and its success­ separate the red and white horizontal line seen by the ful management. patient. In three patients, the cyclotropia was also determined in a 20-degree upward gaze. Special care was taken to align the direction of the rods precisely PATIENTS AND METHODS with the 90-degree mark on the trial frame. A scratch mark on the metal frame of the Maddox rods THIS STUDY INCLUDES ALL 11 PATIENTS OPERATED FOR facilitated this alignment. During measurement of the cyclotropia with horizontal transposition of the verti' cyclotropia, with the eyes in depression and elevation, cal rectus muscle since we began employing this the trial frame had to be lifted up or was allowed to procedure in 1989. We have not included one addi­ slide a small distance down the nasal bridge. Compar­ tional patient whose surgical results have been pub­ ing the measurements, often performed by a different lished.5 One of us (G. K. v. N.) operated on Patients orthoptist on subsequent visits, revealed satisfactory 1, 2, 5, and 7 through 10; another (M.W.C.) operated consistency. on Patients 3, 4, and 6. Both used an identical The patients were reexamined on several occasions surgical technique. before surgery, during the immediate postoperative Patients ranged in age from 19 to 68 years. Causes period of six weeks, and at the last follow-up visit, of cyclotropia included unilateral or bilateral superior which occurred at an average of 17 months after oblique muscle paralysis, orbital fractures, myasthenia surgery (range, three to 30 months). Only three gravis, and incomplete tenectomy of one superior patients had a follow-up of less than one year. oblique tendon during bilateral superior oblique te­ All patients complained of torsional diplopia. Di­ nectomy for an A-pattern exotropia, following two plopia was recorded according to whether it was surgical attempts to complete that muscle's tenecto­ limited to downward gaze, present in downward gaze my. Seven patients had undergone previous muscle and primary position, or present in all positions of surgery on one or both eyes: five had had operations gaze. on the superior oblique muscle (tuck, tenectomy, or For excyclotropia, the inferior rectus muscle was Harada-Ito procedure), one had had horizontal mus­ transposed nasally. Incyclotropia was treated with cle surgery, and one had had advancement of a nasal transposition of the superior rectus muscle, previously recessed inferior rectus muscle. temporal transposition of the inferior rectus muscle, During the initial visit, each patient had a com­ or a combination of both (Patient 1). Patient 7, with plete eye examination including visual acuity deter­ incyclotropia of the right eye, had a coexisting right mination, cycloplegic refraction, ocular motility anal­ hypertropia for which the right superior rectus muscle ysis, and a fundus examination. The ocular motility was recessed and nasally transposed. Patient 8 had a examination was performed by an orthoptist and left incyclotropia associated with a left hypertropia, repeated by an ophthalmologist. It consisted of mea­ for which the inferior rectus muscle was resected and suring the deviation with the prism-and-cover test at advanced 2 mm in addition to being transposed a 6-m fixation distance and in the nine diagnostic temporally. The muscle insertions were transposed positions at a 33-cm fixation distance while accom­ one full muscle width in all patients. The width of the modation was controlled. Ductions and versions were insertion and the distance of the nasal and temporal examined, and overacting and underacting muscles edge of the insertion from the limbus were measured graded from —4 (underaction) to +4 (overaction). before detaching the muscle. Special care was taken Cyclotropia was measured with the Maddox double to reattach the temporal and nasal edges of the rod test, as illustrated by one of us (G. K. v. N.),7 by insertion according to these measurements, as illus­ placing the red Maddox rods in a trial frame in front trated by von Noorden, Jenkins, and Rosenbaum6 in a of the right eye and the white rods in front of the left previous publication. In three patients, surgery was

326 AMERICAN JOURNAL OF OPHTHALMOLOGY SEPTEMBER 1996 TABLE 1

SUMMARY OF PREOPERATtVE AND POSTOPERATIVE DATA

PREOP TORSION POSTOP TORSION CORRECTION FOLLOW- (IN DEGREES) (IN DEGREES) (IN DEGREES) PATIENT SURGICAL UP NO. DIAGNOSIS UP PP DOWN PROCEDURE (MOS) UP PP DOWN UP PP DOWN

1 Multiple right orbital 15 in 20 in 20in RSR ree 5 mm nasal 3 0 0 0 15 20 20 fractures transp., RIR res 4 mm temporal transp., LIR ree 6 mm (adj) 2 Traumatic bilateral 4 ex 8 ex 11 ex RIR nasal transp. 16 0 5 ex 8 ex 4 3 3 SO palsy 3 Orbital floor n.m. 5 ex 10 ex RIR nasal transp., 24 n.m. 0 0 n.m. 5 10 fracture RMR res 4 mm, RLR ree 5 mm 4 Traumatic LSO palsy n.m. 10 ex 10 ex LIR nasal transp. 30 n.m. 0 0 n.m. 10 10 5 Traumatic bilateral n.m. 5 ex 11 ex RIR nasal transp. 15 n.m. 0 0 n.m. 5 11 SO palsy 6 Traumatic RSO palsy 10 ex 10 ex 15 ex RIR nasal transp. 30 0 0 0 10 10 15 7 Ocular myasthenia n.m. 20 in 23 in RSR ree 4 mm nasal 14 n.m. 4 in 6 in n.m. 16 17 transp., LLR ree 5 mm, LMR res 4 mm 8 Blowout fracture h.m. 11 in 14 in LIR temporal transp. 7 n.m. 0 0 n.m. 11 14 of right orbit and 2-mm advancement and resection 9 XT with A pattern n.m. 5 ex 21 ex RIR nasal transp. 18 n.m. 0 10 ex n.m. 5 11 10 Traumatic bilateral n.m. 11 ex 14 ex RIR nasal transp. 25 n.m. 5 ex n.m. n.m. 6 n.m. SO palsy 11 Traumatic bilateral n.m. 7 ex 16 ex RIR nasal transp. 5 n.m. 5 ex 10 ex n.m. 2 6 SO palsy

Adj. indicates adjustable suture; ex, excyciotropia; in, incyclotropia; LIR, left inferior rectus; LLR, left lateral rectus; LSO, left superior oblique; n.m., no measurement; PP, primary position; ree, recession; res., resection; RIR, right inferior rectus; RLR, right lateral rectus; RMR, right medial rectus; RSO, right superior oblique; RSR, right superior rectus; SO, superior oblique; transp., transposition; XT, exotropia. performed during the same session on the fellow eye whom it ranged from 4 degrees to 15 degrees. Nasal to correct a coexisting hypertropia (Patient 1) or transposition of the superior rectus muscle and tem­ exotropia (Patients 3 and 7). poral transposition of the inferior rectus muscle was performed in Patient 1 and produced a correction of 15 degrees in upward gaze and of 20 degrees in RESULTS primary position and downward gaze. No overcorrec- tion was observed. THE RESULTS ARE LISTED IN TABLE 1. THE AMOUNT OF A functional cure, defined as absence of torsional cyclotropia corrected by horizontal transposition of or other diplopia in the practical field of fixation (15 the vertical rectus muscles ranged from 2 degrees to degrees to 20 degrees from the primary position) was 16 degrees (mean, 7 degrees) in primary position. achieved in six patients. In Patients 2 and 7, torsional This effect was larger in downward gaze, where it diplopia, formerly present in all gaze positions, was ranged from 3 degrees to 20 degrees (mean, 11 limited to downward gaze after surgery. These pa­ degrees). Preoperative and postoperative measure­ tients were considered to be improved, as were ments in the functionally less important upward gaze Patients 9, 10, and 11, who had sufficient reduction of position were available in only three patients, in their cyclotropia but required additional surgery for

VOL.122, No. 3 HORIZONTAL TRANSPOSITION OF VERTICAL RECTUS MUSCLES FOR CYCLOTROPIA 327 hypertropia before fusion was restored in the practical TABLE 2 field of fixation. To determine the stability of the surgical results, we STABILITY OF SURGICAL RESULTS compared measurements for cyclotropia taken during the immediate postoperative visit (one to six weeks) -ONG-TERM POSTOPERATIVELY (IN DEGREES) with those obtained at the last follow-up visit, an IN DEGREES) YR OR LONGER) PATIENT (1 average of 17 months after surgery (range, three to 30 NO. pp. DOWNGAZE pp. DOWNGAZE months). Patient 5 had to be excluded from this 2 6ext 10 ex 5 ex 8 ex comparison by virtue of being unavailable for meas­ 3 0 0 0 0 urements during the immediate postoperative period. 4 0 0 0 0 The comparison, presented in Table 2, shows not only 6 0 0 0 0 no recurrences of cyclotropia but also further im­ 7 15 in* n.m.§ 4 in 6 in 9 2 ex 12 ex 0 10 ex provement in Patient 7 in the course of time. 10 6 ex n.m. 5 ex n.m. An interesting postoperative complication oc­ curred in Patient 11 and required additional surgery. *PP indicates primary position. This 54-year-old man had complained of diplopia tex indicates excyclotropia. *in indicates incyclotropia. since being thrown from a horse eight months §n.m. indicates no measurement. previously and suffering a subdural hematoma. His clinical findings were consistent with a bilateral was present in primary position, increased to 23 prism superior oblique paralysis. He had right hypertropia in diopters in downward gaze, and 10 prism diopters in left gaze and a left hypertropia in right gaze. Ductions adduction. The patient had a residual right excyclo­ and versions showed — 2 underaction of both superior tropia of 5 degrees in primary position and 10 degrees oblique muscles, and overaction of the right inferior in downward gaze but was able to fuse with a 20-prism rectus muscle. The Maddox double rod test showed a diopter prism held base down in front of his right eye. right excyclotropia of 10 degrees in primary position There was an underaction of —2 in the field of action and downward gaze, and a left excyclotropia of 6 of the right superior oblique muscle compared with an degrees in downward gaze. underaction of — 1 before nasal transposition of the We performed a 6-mm tuck of both superior right inferior rectus muscle. We briefly entertained the oblique tendons (G. K. v. N.). The patient felt much possibility that the nasally transposed inferior rectus improved one week postoperatively and traveled muscle had partially disinserted. However, in view of home but returned five months after surgery com­ the gradual onset of the vertical diplopia and normal plaining of continued visual confusion in downward ductions in the field of action of the right inferior gaze. He fused in primary position and upward gaze rectus muscle, we favored the hypothesis that nasal but had a right excyclotropia of 16 degrees in down­ transposition of the inferior rectus muscle in the ward gaze. There was residual underaction ( — 1) of presence of a residual superior oblique paresis reduces the right superior oblique muscle, and the action of depressor function sufficiently to create an imbalance the left superior oblique muscle had become normal. between elevating and depressing muscles. Therefore, We performed a nasal transposition of the right rather than exploring the right inferior rectus muscle, inferior rectus muscle (G. K. v. N.). One week after we recessed the left inferior rectus muscle on an surgery, the patient still complained of visual confu­ adjustable suture (G. K. v. N.). One week after sion in downward gaze. He had residual right and left surgery, the patient was free of complaints. He fused excyclotropias of 4 degrees in primary position and of in all gaze positions. A residual right excyclotropia of 7 degrees in downward gaze. Five months later, he five degrees in downward gaze was measured but not presented again, complaining of vertical diplopia, noted by the patient, who overcame this residual which he said had slowly developed and increased deviation with cyclofusion. since the time of the last operation. Prism-and-cover Since preparation of this paper, an additional testing showed a dramatic change from the postopera­ patient with superior oblique paralysis and excyclotro­ tive findings. A right hypertropia of 7 prism diopters pia of the paralyzed eye has come to our attention.

328 AMERICAN JOURNAL OF OPHTHALMOLOGY SEPTEMBER 1996 This patient developed a large hypertropia after nasal surgery on both vertical rectus muscles of the cyclo- transposition of the inferior rectus muscle by another tropic eye. surgeon. We do not advocate this operation on both vertical rectus muscles in older patients who have had previ­ ous horizontal muscle surgery on the same eye. DISCUSSION Disinsertion of all four rectus muscles, even if per­ formed in two stages with an interval of many years, HORIZONTAL TRANSPOSITION OF THE VERTICAL RECTUS poses a distinct risk of anterior segment ischemia. In muscles was described by Mumma,8 who transposed such cases, it is safer to transpose vertically the the inferior rectus muscle nasally and the superior previously operated horizontal rectus muscles10 (medi­ rectus muscle temporally in a 3-year-old boy with a al rectus muscle upward and lateral rectus muscle surgically proven congenital absence of the right downward for excyclotropia), even though in our superior oblique muscle and a head tilt to the left. experience this approach is less effective than trans­ The head tilt improved after surgery, but no mention posing the vertical rectus muscles. was made of preoperative or postoperative cyclotropia, The stability of the effect of surgery shown in this which may have been difficult to diagnose in a child study is contrary to that observed after the Harada-Ito of that age. We have shown subsequendy that this procedure, the effect of which tends to decrease with operation reduces excyclotropia5 and is also useful for time.11'14 In view of the resiliency of orbital tissues and producing excyclotorsion or incyclotorsion of the the counteracting pull from the muscles not operated globes in the treatment of a head tilt secondary to on, we had actually expected the same tendency to congenital nystagmus with a neutral point in tertiary prevail after this procedure. Instead, the opposite gaze.6 In this study, we have shown that vertical rectus occurred. Recurrence was not observed, and Patient 7 transposition works equally well in incyclotropia and experienced additional improvement in primary posi­ excyclotropia. Although its quantitative effect may tion while under postoperative observation. Fundus vary, our results were stable and led to significant photographs were not available to determine whether functional improvement in all patients during the this improvement occurred on a sensory or motor period of observation. basis. Most patients obtained a correction ranging from It is difficult to compare the average cyclorotation 10 degrees to 15 degrees in downward gaze from nasal after this operation (7 degrees in primary position and transposition of the inferior rectus muscle. However, 11 degrees in downward gaze) with the effectiveness others were affected less despite an identical surgical of some of the other procedures advocated for treating technique. Although this variance is difficult to cyclotropia. Such information has not been included explain, it did not present a problem in this series in the description of surgery on the insertions of the regarding functional outcome. All our patients had superior and inferior oblique muscles.15 Spielmann16 acquired cyclotropia and were thus good candidates observed a correction of 15 degrees excyclotropia in for fusion. Although there was a residual cyclodevia- one patient after slanting the insertion of all four tion in six patients, all benefited functionally once the rectus muscles. However, slanting all four rectus cyclotropia had been reduced sufficiently to fall within muscle insertions may involve risk to the blood supply the cyclofusional range. This range can extend to 15 of the anterior segment in older patients or those degrees in normal patients.9 Therefore, it is not having previous surgery. The average long-term ef­ necessary to strive for full correction of cyclotropia. fects of the Harada-Ito operation are nearly identical When cyclotropia reaches unusually large propor­ to those of our operation and amount to 8.3 degrees tions, as in Patient 1, a transposition of the superior in primary position and 10.6 degrees in downward rectus muscle as well as surgery on the inferior rectus gaze (Kapp ME, von Noorden GK, unpublished data, muscle may be warranted. This woman noted cyclo­ 1994). tropia after repair of multiple fractures of the orbital The fact that the operation performed on the bones and had a right incyclotropia of 20 degrees in inferior rectus muscle had a greater effect in down­ all positions of gaze; this was completely corrected by ward gaze than in primary position is not surprising,

VOL.122, No. 3 HORIZONTAL TRANSPOSITION OF VER RECTUS MUSCLES FOR CYCLOTROPIA 329 for it is in downward gaze that the transposed inferior muscle, and inferior oblique muscle at an advantage. rectus muscle develops its greatest cyclorotatory force. We cannot explain why this complication did not In our experience, the most common cause of cyclo- occur in Patients 2, 4, and 6. These patients had nasal tropia is unilateral and, especially, bilateral superior transposition of the inferior rectus muscle in the oblique paralysis of recent onset. In such patients, the presence of a residual ipsilateral superior oblique greatest amount of cyclotropia is always in downward muscle paresis. Because this problem responded readi­ gaze. Nasal transposition of the inferior rectus muscle ly to additional surgery, it should not be considered a appears ideally suited to correct this condition. Trans­ contraindication to nasal transposition of the inferior posing the superior rectus may be added to achieve a rectus muscle for excyclotropia. greater effect when the cyclotropia reaches unusually large proportions, as in Patient 1. We propose that nasal transposition of the inferior rectus muscle is not only a viable alternative to the REFERENCES Harada-Ito procedure for excyclotropia but also may actually be preferable for the less-experienced surgeon 1. Guyton DL, von Noorden GK. Sensory adaptations to who may find it difficult to work on the anterior cyclodeviations. In: Reinecke RD, editor. Strabismus. New York: Grune & Stratton, 1978:399-403. aspect of the superior oblique tendon. Nasal transpo­ 2. Ruttum M, von Noorden GK. Adaptation to tilting of the sition of the inferior rectus muscle becomes the visual environment in cyclotropia. Am J Ophthalmol procedure of choice for patients who have had previ­ 1983;96:229-37. 3. von Noorden GK. Clinical and theoretical aspects of cyclo­ ous surgery on the superior oblique tendon, or in tropia. J Pediatr Ophthalmol Strabismus 1984;21:126-32. whom congenital absence of that tendon precludes 4. Harada M, Ito Y. Surgical correction of cyclotropia. Jpn J surgery. Nasal transposition of the superior rectus Ophthalmol 1964;8:88-96. 5. von Noorden GK, Chu MW. Surgical treatment options in muscle, temporal transposition of the inferior rectus cyclotropia. J Pediatr Ophthalmol Strabismus 1990;27: muscle, or both, are the only procedures proven to be 291-3. effective for treating incyclotropia. No comparably 6. von Noorden GK, Jenkins RH, Rosenbaum AL. Horizontal transposition of the vertical rectus muscles for treatment of effective operation exists. ocular torticollis. J Pediatr Ophthalmol Strabismus 1993; The large hypertropia developing after surgery in 30:8-14. 8 7. von Noorden GK. Binocular vision and ocular motility, 5th Patient 11 deserves special comment. Mumma, de­ ed. St. Louis: C. V. Mosby, 1996:191. scribing this operation for head tilt in a patient with 8. Mumma JV. Surgical procedure for congenital absence of the congenital absence of the superior oblique muscle, superior oblique. Arch Ophthalmol 1974;92:221-3. 9. Guyton DL. Ocular torsion: sensorimotor principles. Graefes mentions the possibility that a nasally transposed Arch Clin Exp Ophthalmol 1988;226:241-5. inferior rectus muscle may lose some of its depressing 10. de Decker W. Rotatorischer Kestenbaum an geraden Augen­ power. This has been verified by a computational muskeln. Z Prakt Augenheilkd 1990;11:111-4· 11. Bérard PV, Peydy R, Mouillach—Gambarelli N. La technique simulation of nasal transposition of the inferior rectus de Harada et Ito dans le traitement des cyclotropies isolées. muscle, carried out at our request at the Jules Stein Bull Soc Ophtalmol Fr 1977;77:341-2. Eye Institute, University of California, Los Angeles 12. von Noorden GK. Clinical observations in cyclodeviations. Ophthalmology 1979;86:1451-61. (Park C, Demer J, written communication, 1995) 13. Mitchell PR, Parks MM. Surgery for bilateral superior oblique with a program developed for such purposes by palsy. Ophthalmology 1982;89:484-8. Miller.17 The simulation also predicted that, in the 14. Toria RN, Nelson LB, Calhoun JH, et al. Surgical correction of excyclotropia. Am Orthopt J 1985;35:63-7. presence of a weak superior oblique muscle, this 15. Conrad HG, de Decker W. 'Rotatorischer Kestenbaum'— weakness of depression of the adducted eye will be Umlagerungschirurgie bei Kopfzwangshaltung zur Schulter. vastly enhanced by nasally transposing the inferior Klin Monatsbl Augenheilkd 1978;173:681-90. 16. Spielmann A. The "oblique" Kestenbaum procedure revisited rectus muscle. Patient 11 had residual underaction of (sloped recession of the recti). In: Lenk-Schafer M, editor. the previously tucked right superior oblique muscle. Orthoptic Horizons: Transactions of the Sixth International The slowly developing postoperative right hypertropia Orthoptic Congress. Harrogate, UK: 1987:433. 17. Miller JM. Orbit 1.5 Gaze Mechanics Simulation. San may well have been caused by an imbalance of muscle Francisco, California: Eidactics Visual Biosimulation, 1995. forces, putting the ipsilateral elevators, superior rectus

330 AMERICAN JOURNAL OF OPHTHALMOLOGY SEPTEMBER 1996