Bilateral lateral rectus recession for consecutive exotropia

Bilateral Lateral Rectus Recession for Consecutive Exotropia Avani S. Patel, BS,a John W. Simon, MD,a,b and Lloyd L. Lininger, PhDc Introduction: Treatment of consecutive exotropia after bilateral medial rectus recessions has been rarely studied. Though several series have reported results of medial rectus advancement, none has described results of lateral rectus recessions. Methods: We reviewed our results in 31 patients who underwent bilateral lateral rectus recessions for consecutive exotropia after bilateral medial rectus recessions. Mean follow-up was 30 months (range, 1-140 months) after the exotropia repair. Results: At last follow-up, 20 of 31 patients (65%) had deviations of less than or equal to 10 PD. Limitation of adduction was not apparent. Discussion: Cooper’s dictum states that lateral rectus recession should be performed instead of medial rectus advancement. Our results suggest that this approach is generally successful. The outcome after exotropia repair in consecutive deviations is comparable to that after repair of primary exotropia. (J AAPOS 2000;4:291-4)

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n outward ocular deviation that develops immediately or for many years after surgery for esotropia is called a consecutive exotropia. The entity has been the subject of a number of reports and has been noted in as many as 27% of patients after they underwent surgery for infantile esotropia.1-6 Among characteristics thought to predispose patients to the development of consecutive exotropia are developmental delay, amblyopia, large medial rectus recessions, high hyperopia, associated vertical deviations, A and V patterns, and nystagmus.7,8 Although consecutive exotropia is apparently common, its treatment has not been well studied. It has been our consistent practice to perform bilateral medial rectus recessions in esotropic patients with normal versions and good vision in both eyes. We have followed “Cooper’s dictum”11 in treating consecutive deviations in these patients, choosing to recess the previously unoperated lateral rectus muscles rather than to undo the surgery on the medial rectus muscles. We report our experience with this treatment and compare our results with those of authors who have advanced the medial rectus muscles. We also compare our data with the results we gathered after bilateral lateral rectus recessions in patients with primary exotropia.6

From the Lions Eye Institutea and Department of Ophthalmology,b Albany Medical College, Albany, New York; and the Department of Biometry and Statistics, School of Public Health, University at Albany, Rensselaer, New York.c Submitted January 22, 1998. Revision accepted May 28, 1999. Reprint requests: John W. Simon, MD, Department of Ophthalmology, Albany Medical College, Lions Eye Institute, 35 Hackett Blvd, Albany, NY 12208. Copyright © 2000 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2000/$12.00 + 0 75/1/109738 doi:10.1067/mpa.2000.109738

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PATIENTS AND METHODS Between 1981 and 1998, the second author (J.W.S.) performed recession of both medial rectus muscles in approximately 700 patients because of esotropia. The records were reviewed of all patients who underwent recession of both lateral rectus muscles (BLR recession) at Albany Medical Center, pediatric ophthalmology service, for consecutive exotropia after such surgery. A total of 33 patients were identified. One patient was excluded because of inadequate follow-up and another because of an intervening resection of both lateral rectus muscles for residual esotropia. In 19 patients, vertical rectus or inferior oblique surgery was performed as part of either operation or as a separate procedure. Five patients underwent vertical transpositions of medial or lateral rectus muscles concurrently. The final study group contained 31 patients (Table 1). The study group consisted of 15 males and 16 females, ranging in age at the time of lateral rectus recession from 19 to 417 months (mean, 90 months). Amblyopia occurred at some point in the course of 16 patients (52%). Only 2 patients (7 and 31) had more than 1 line difference in visual acuities between eyes. When possible, alignment was measured by using the alternate prism cover test, with the patient fixating accommodative targets at distance and near. If the patient was too young to cooperate for such testing, the Krimsky and Hirschberg methods were substituted. The mean age at the time of esotropia surgery was 23 months (range, 7-111 months). Esotropia, measured at distance with full hyperopic correction (if prescribed), averaged 43 PD (range, 15-70 PD). Bilateral medial rectus recessions were performed according to a standard surgical table and ranged from 3.0 to 7.0 mm.8 Alignments measured

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292 Patel, Simon, and Lininger TABLE 1. Surgical treatment and follow-up of initial esotropia and consecutive exotropia Initial surgery Patient No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Age at Preop BMR (mo) esotropia (PD) 8 8 68 10 8 51 27 20 23 21 17 12 13 26 8 7 7 10 17 17 14 26 9 9 32 83 29 111 18 7 11

55 40 30 40 60 23 70 40 30 50 50 50 60 20 35 38 15 45 30 27 32 50 65 70 47 50 35 28 40 40 65

Reoperation

Surgical dosage (BMR) (mm)

1-mo postop alignment (PD)

Time to reop (mo)

6 5 4.75 5 6 3.5 6.5 5 4 5 6 5.5 5 4 5.5 5 3 5.5 4.5 4.5 4.5 5.5 6.25 6.5 4.5 6 4.5 4 5 5 7

ET, 5 Ortho Ortho XT, 10 Ortho Ortho Ortho Ortho XT, 10 Ortho Ortho Ortho Ortho Ortho Ortho Ortho Ortho Ortho ET, 4 XT, 12 Ortho Ortho ET, 5 Ortho Ortho XT, 30 XT, 2 XT, 14 XT, 10 Ortho Ortho

30 21 13 9 32 35 33 121 37 396 10 99 163 73 76 13 39 10 96 106 33 44 55 54 133 52 41 23 74 49 87

Preop exotropia (PD) Dist 20 25 35 30 25 35 30 30 37 35 40 20 45 25 30 40 40 20 60 40 32 18 22 40 40 20 25 18 25 70 25

Near 5´ 4´ 40´ Ortho´ 18´ 20´ 55´ 25´ 37´ 40´ 35´ 8´ 50´ Ortho´ 20´ 20´ 40´ 30´ 60´ 35´ Ortho´ 12´ 14´ 20´ 40´ 20´ 16´ 25´ 25´ 20´ 12´

Surgical dosage (BLR) (mm) 4.25 5 7 6 5 5.75 6 5.75 7 8 8 3.75 8.5 4.5 5.75 7 7 4.5 9.5 7 6 4.5 5 8 7 4.5 5.5 5.5 5 7.75 6

BIO, Bilateral inferior oblique recession; BLR, bilateral lateral rectus recession; BMR, bilateral medial rectus recession; BSR, bilateral superior rectus recession; ET, esotropia; LIO, left inferior oblique recession; LSR, left superior oblique recession; ORTHO, orthotropia; RIO, right inferior oblique recession; XT, exotropia; (1), other surgery performed at the time of BMR; (2), other surgery performed at the time of BLR; (sep), other surgery performed as a separate procedure.

approximately 1 month after this surgery are given in Table 1. Only 3 patients had exotropia greater than 10 PD at this point. The interval between surgeries for esotropia and exotropia averaged 66 months (range, 9-396 months). Consecutive exotropia, measured with correction if prescribed, averaged 32 PD (range, 18-70 PD) at the time of bilateral lateral rectus recessions. Lateral rectus recessions were performed according to a standard surgical table and ranged from 3.75 to 9.5 mm.6 Surgery for intermittent exotropia was planned for the largest deviation on alternate prism cover testing. In 11 patients, the distance exotropia was more than 10 PD larger than the deviation at near. In 1 patient, the near exotropia was more than 10 PD larger than the distance deviation. Results gathered after BLR recession were analyzed by using a survival curve. Survival (or success) was defined as

distance alignment less than or equal to 10 PD of exotropia or esotropia. Spectacle manipulation was successfully used after exotropia surgery in patient 28; the hyperopic correction was increased because of a postoperative esotropia, which proved to be accommodative. Mild limitation of adduction was noted before exotropia surgery in 2 patients but was no longer apparent after lateral rectus recession and at last follow-up.

RESULTS Alignments measured approximately 1 month after lateral rectus recession and at last follow-up are given in Table 1. The follow-up documented after lateral rectus recession ranged from 1 to 140 months (mean, 30 months). All but 11 of our patients had successful outcomes at last followup. Eight patients had residual exotropia and 3 had esotropia. Of the patients with unsuccessful outcomes, 2

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Final status Other surgeries BIO (2) BIO (sep) BIO (1) None BIO (1,2) None None BIO (1,2) None None BIO (2) BIO (sep) BIO (1,2) BIO (1); RIO; LSR (sep) BSR (2); BIO (sep) BIO (2) BIO (2) None None BIO (1); LIO (2) BSR (2) BIO (2) BSR (2) BIO (2) None None None None BSR (2) None BIO (1)

Deviation (PD) Dist

Near

0rtho ET, 16 ET, 25 ET, 16 ET, 5 Ortho ET, 10 Ortho XT, 12 XT, 8 Ortho Ortho XT, 12 XT, 16 ET, 4 Ortho XT, 25 ET, 10 XT, 4 XT, 10 ET, 10 Ortho Ortho XT, 12 XT, 20 XT, 8 XT, 25 Ortho XT, 12 XT, 30 ET, 10

Ortho´ ET´, 30 ET´, 25 ET´, 35 ET´, 16 ET´, 18 XT´, 4 Ortho´ XT´, 12 XT´, 8 Ortho´ ET´, 6 XT´, 12 Ortho´ ET´, 4 XT´, 4 XT´, 30 ET´, 10 XT´, 4 XT´, 20 ET´, 12 Ortho´ Ortho´ Ortho´ XT´, 20 XT´, 12 XT´, 20 Ortho´ XT´, 24 ET´, 20 ET´, 8

Last postop follow-up (mo) 32 140 51 32 75 28 21 3 11 1 1 3 1 13 22 55 62 8 83 1 47 19 32 24 13 34 64 42 4 50 13

with exotropia required yet another horizontal surgery. Distance-near disparities were less prominent after exotropia surgery. Before BLR recessions, 11 patients had distance exotropias of greater than 10 PD larger than their near alignments. After BLR recessions, 6 patients had greater than 10 PD more divergence at distance. Amblyopia was not statistically associated with an unsuccessful outcome (P = .30, χ2 and Mantel-Haenszel tests).

DISCUSSION In 1961, Edmond L. Cooper suggested that overcorrections that occur after strabismus surgery should be evaluated anew on the basis of the deviation following the last surgery.11 “Cooper’s dictum” was first applied in cases of consecutive exotropia: “It is inadvisable to assume the attitude that one should undo some of the surgery which has been done.” Instead of advancing the recessed medial recti

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muscle, Cooper and, subsequently, von Noorden have advocated recessing the lateral rectus muscles.12 This has been our practice for the past 18 years. We were surprised to find that no series has investigated the success of this approach. Of our 31 patients, 20 (65%) had less than or equal to 10 PD of horizontal deviation at a mean follow-up of 30 months after the operation. Our results are comparable to those of other authors, none of whom used a consistent surgical approach for either primary esotropia or consecutive exotropia. Ohtsuke et al9 advanced one or both medial rectus muscles to the original insertion in 24 patients who had undergone a variety of procedures for esotropia. Preoperatively, there was an average of 27 PD of exotropia. Postoperatively, 46% of patients were realigned within 10 PD, with 6 patients having overcorrections and 8 having residual exotropias. To enhance the effect of single medial rectus advancement, Biedner et al10 advocated reattaching the muscle anterior to its original insertion. Of their 3 patients, 2 were aligned within 10 PD after a minimum of 14 months followup. Five other patients underwent advancement of the medial rectus muscle only to the insertion. Of these, all had less than 10 PD of horizontal deviation at last follow-up. A variety of factors, including surgical dosages and patient selection, make comparisons of alternative surgical approaches problematic. Only a randomized, controlled trial could determine the best treatment of consecutive exotropia. Two theoretical advantages favor lateral rectus recessions over medial rectus advancement. The surgical dosages are available in tables, which can be used as if the exotropia were a primary deviation. Recessing previously unoperated lateral rectus muscles is technically easier than advancement of previously operated medial rectus muscles. On the other hand, patients with evidence of medial rectus muscle slippage as the cause of consecutive exotropia would probably do better with retrieval and advancement of the slipped muscle. Overall, distance-near disparities were improved after BLR recessions, even in the 1 patient with a convergence insufficiency pattern (patient 7). The current series was compared with 57 of our own patients, previously reported, who underwent bilateral lateral rectus recessions according to the same surgical formula for primary exotropia.6 The Mantel-Haenszel (log-rank) test was used to compare the time to failure for the 2 series of patients. No statistically significant difference in the failure times for the 2 groups was present (P = .09). The prognosis for long-term alignment after surgery for consecutive exotropia appears to be comparable to that after correction of primary exotropia. References 1. Dunnington JH, Regan EF. Factors influencing the postoperative result in concomitant convergent strabismus. Arch Ophthalmol 1950;44:813-22.

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294 Patel, Simon, and Lininger 2. Bietti GB, Bagolini B. Problems related to surgical overcorrections in strabismus surgery. J Pediatr Ophthalmol Strabismus 1965;2:11-4. 3. Hiles DA, Watson BA, Biglan AW. Characteristics of infantile esotropia following early bimedial rectus recession. Arch Ophthalmol 1980;98:697-703. 4. Folk ER, Miller M, Chapman L. Consecutive exotropia following surgery. Br J Ophthalmol 1983;67:546-8. 5. Caputo A, Guo S, Wagner RS, Picciano MV. Long-term follow-up of extraocular muscle surgery for congenital exotropia. Am Orthoptic J 1991;41:67-71. 6. Stoller SH, Simon JW, Lininger LL. Bilateral lateral rectus recession for exotropia: a survival analysis. J Pediatr Ophthalmol Strabismus 1994;31:89-92. 7. Pickering JD, Simon JW, Ratliff D, Melsopp KB, Lininger LL. Alignment success following medial rectus recessions in normal

8.

9.

10.

11. 12.

and delayed children. J Pediatr Ophthalmol Strabismus 1995; 32:225-7. Pickering JD, Simon JW, Lininger LL, Melsopp KB, Pinto GL. Exaggerated effect of bilateral medial rectus recession in developmentally delayed children. J Ped Ophthalmol Strabismus 1994;31:374-7. Ohtsuke H, Hasebe S, Tadokoro Y, Kobashi R, Watanabe S, Okano M. Advancement of medial rectus muscle to the original insertion for consecutive exotropia. J Pediatr Ophthalmol Strabismus 1993;30:301-5. Biedner B, Yassur Y, David R. Advancement and reinsertion of one medial rectus as treatment for surgically overcorrected esotropia. Binocul Vis Q 1991;6:197-200. Cooper EL. The surgical management of secondary exotropia. Trans Am Acad Ophthalmol Otolaryngol 1961;65:595-608. Burien HM, von Noorden GK. Binocular vision and ocular motility. St Louis: CV Mosby; 1974. p. 464.

An Eye on the Arts – The Arts on the Eye According to Empedocles, the divine Aphrodite, goddess of love, fashioned our eyes out of the four Greek elements of earth, water, air, and fire, fitting them together with rivets of love. Then “as when a man, thinking to make an excursion through the night, prepares a lantern,” lighting it at the brightly blazing hearth fire and fitting it around glass plates to shield it from the winds, so did Aphrodite kindle the fire of the eye at the primal hearth fire of the universe, confining it with tissues in the sphere of the eyeball. Marvelous passages were fitted into the eye, permitting it to transmit a fine interior fire through the water of the eye and out into the world, thereby giving rise to sight. Sight proceeded from the eye to the object seen; the eyes rayed out their own light. —Arthur Zajonc (from Catching the Light: The Entwined History of Light and Mind p 20)