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Home , Management of strabismus, Retinal detachment, Strabismus

Eye (1991) 5, 451-455

Treatment of After Surgery With Botulinum Neurotoxin A

JOHN LEE, BRIAN PAGE, JONATHAN LIPTON London

Summary Thirty-one consecutive patients were treated with injections of Botulinum Neu­ rotoxin A to rectus muscles for strabismus following retinal detachment surgery. In 14 cases the presenting problem was and in 17 cases the presenting problem was cosmetic appearance. A total of 67 injections was given. Twenty-seven cases had nine months or more follow-up. Of these, four of 11 cases with diplopia had fusion restored, four were shown to have no fusion potential, and three had temporary improvement only. In 16 cases with a primary cosmetic problem there was no useful effect in two, three had surgery as an alternative, three were realigned long-term, and eight had continuing maintenance therapy with toxin. Over half the series had undergone multiple detachment surgery, often for giant tears and other complex pathology.

Ocular motility problems following retinal surgeons at Moorfields Hospital, many detachment surgery are not uncommon. being tertiary referrals from other ophthalmic Retrospective studies1--l have shown an inci­ units. dence of up to 14% of post-operative motility

dysfunction, while prospective studies have Pre-Injection Findings-Table I shown an even higher incidence with up to Thirty-one consecutive patients are reported. 73% of patients showing limited ocular move­ All attended the Toxin Clinic for strabismus at ments in the immediate post-operative Moorfields Eye Hospital between March 1983 period. 5-7 Several series have correlated per­ and September 1990. The sex ratio was 20 lIisting ocular motility problems with encircle­ males to 11 females and the age range was ment, re-operations and large explants from 20 to 73 years with a mean of 43. Twenty­ especially in contact with rectus muscles. six patients had undergone unilateral retinal Little has been written on management of reattachment surgery. A single procedure was thi� disabling ,H-11 but there is performed in 13 cases, six had two proce­ general agreement that muscle surgery is diffi­ dures, three had three, three had four and two cult and may be contra-indicated if there is a had six procedures. risk oj redetachment or explant extrusion. Bilateral detachment surgery had been per­ Accordingly, a treatment technique which formed in four cases. Two had one procedure does not increase muscle fibrosis or disturb on each eye, one had two and three proce­ expl

FWIll Ihe Toxin Clinic, Moorficlds Eye Hospital, London. Corrl"pondence to: John Lee, MRCP, FRCS, FCOphth, Moorfields Eye Hospital, City Road, London £CI\ ..'PO. 452 1. LEE ET AL.

Table I Pre-injection findings

Retinal Strabismus Primary Case Age Sex Aetiology Surgery Surgery Problem BSV Deviation

I. 20 M Trauma xl Cosmesis N 12XT, 20 RHT 2. 29 M IO FB+ FT x2 Cosmesis N 45XT 3. 32 F Primary x6 Cosmcsis Y 40XT 4. 29 M Primary x2 xl Diplopia ? 50 R hypo 5. 35 F Primary xl Diplopia Y 45ET 6. 52 M Trauma xl Diplopia Y 25XT 7. 72 M Primary xl Diplopia ? 35XT 8. 31 M Trauma x2 xl Cosmesis N 25ET 9. 68 F Primary xl Diplopia ? 40XT distortion 10. 21 M Trauma xl Cosmesis N 18ET II. 37 M Congo Cat. xl, xl Diplopia Y 18ET 12. 28 M IO FB+GT x3 Cosmesis N 50ET 13. 48 F Congo Cat. x3, x2 Cosmcsis N 45ET 14. 48 M Primary x6 Diplopia N 30ET 15. 60 F Primary x3 Cosmesis Y 25ET 16. 51 M n.k. n.k. Diplopia ry 35XT 17. 73 F xl Cosmcsis N 35XT 18. 48 M IO FB x2 xl Diplopia N 45XT 19. 68 M DP R x4 Cosmesis N 20ET,7LHT 20. 38 M Aphakia xl Diplopia 25ET 21. 33 M Trauma x2 Cosmesis N 45XT 22. 21 F GT xl Cosmcsis N 25ET 23. 60 M Primary x3 x2 Cosmcsis N 18ET 24. 20 F Bilat. GT xl. xl xl Cosmesis N 60XT 25. 32 F DP R x4 Cosmesis N 35XT 26. 38 M Primary x4, x3 Cosmesis N 35ET 27. 43 F DP R xl Diplopia ') 25XT 28. 25 M Primary xl Cosmesis N 50XT 29. 52 M Primary xl Diplopia ') 20XT distortion 30. 64 M Primary x2 Diplopia ') 25XT 31. 58 F Primary xl Diplopia ? 45ET

Abbreviations: IO FB = Intraocular foreign body

GT = Giant retinal tear

DP R = Diabetic proliferative

ET =

XT =

HT =

n.k. = not known

cases had post-traumatic detachment follow- in the injected eye is shown in ing penetrating injury, intra-ocular foreign Table II. It will be seen that half the series had body or dislocated . Four had giant retinal visual acuity in the injected eye less than 6/60, tears, In one case bilaterally. Two had a just over a quarter had 6/60 vision and just history of congenital . Five had under- under a quarter had vision better than 6/60.lt gone previous unsuccessful strabismus sur- is clear that the cosmetic group had poorer gery. All cases had a minimum of one year vision, but notable that even in patients with since their last detachment surgery. poor foveal function, diplopia may be a major In 17 cases the presenting symptom was symptom. poor cosmesis and in 14 the problem was dip- Pre-operative motility examination showed lopia. In addition there were supplementary that 14 cases were esotropic with a range o� complaints of distortion in two patients and 18-50 prism and a mean of 30 PD, glare in one patient. Sixteen cases were exotropic, with a range of TREATMENT OF STRABISMUS 453

Table II Visual acuity Results--Tables IlIa and IlIb Four cases-numbers 28-31-have been Diplopic Cosmetic Total excluded because of short follow-up. The remainder are divided into a 'diplopia' group NPL 1 1 and a 'cosmetic' group. In the diplopia group, PL 2 2 <6/60 -50% HM 1 4 5 =6/60 -26.6% four of 11 were shown to have no fusion CF 1 3 4 >6/60 -23.4% potential because of macular distortion and 1160 2 1 3 no further treatment was advised. Two cases 6/60 4 4 8 had temporary partial improvement and later 6/36 1 1 6/ 24 2 1 3 had surgery. One case had attempted injec­ 6/ 12 2 2 tion but no EMG could be obtained and no 6/9 1 1 injection was given. n.k. 1 1 Four cases (Nos. 5, 6, 11, 20) had their deviation eliminated and fusion restored. In 12-60 PO and a mean of 36 PO. Two cases of two cases the realignment was stable. Case 5 vertical strabismus were treated. Case 1 had continues to·have injections at approximately 12 PO exotropia and 20 PO right hypertropia yearly intervals to maintain her alignment. and had injection of right lateral and superior Case 11 elected for surgery 17 months after toxin treatment. recti on the same occasion. Case 4 had a � 50 PO right hypotropia. In the c smetic group of 16 patients two bad Pre-operatively the status no useful effect from toxin injection, three was investigated with prism, synoptophore had temporary reduction in the deviation but and stereo tests. In six cases there was later surgery, three were aligned long-term, unequivocal evidence of good binocular and eight continued to attend the Toxin Clinic vision, in eight there was poor or dubious bin­ for maintenance therapy to improve cosme­ ocularity and in 17 cases no binocular vision sis. One (Case 2) has since had_surgery as an potential was detected. alternative after five years of toxin treatment. Complications were minor and transient. Treatment occurred after three injections and sub­ All cases were treated with intramuscular conjunctival haemorrhage after two injection of purified Botulinum Neurotoxin A injections. in isotonic saline in a volume of 0.1 m!. All injections were performed with continuous Discussion EMG monitoring with audible and visible dis­ In this study we have reviewed 31 patients plays of the signal. A Medelec MS6 amplifier/ who underwent a total of 67 previous retinal recorder and 27-gauge monopolar electrodes detachment procedures. Sixty-seven injec­ were used throughout. tions of were attempted, Case 1 had two injections of US-produced although in one patient no EMG signal was toxin from Or Alan Scott's laboratory at a obtained and no injection given. What benefit concentration of 312 picograms in 0.1 ml. was experienced by the use of this agent? Case 2 had three injections of US toxin in the In the diplopia group four cases were shown 312 picogram dose and one injection of 1,560 to have no potential for binocular vision, picograms. All other injections in this series thereby informing both surgeon and patient were of UK-produced toxin from the labora­ that further attempts to straighten the tory of Professor J. Melling, CAMR, Port on would not relieve diplopia. A further four Down. All doses were 62.5 picograms in cases were shown to have good fusion. Two 0.1 1111 of isotonic saline. Sixty-seven injec­ remained stable, one had surgery and one has tions were given to the 31 patients. The yearly injections to maintain a controllable number of injections per patient is shown in phoria. In the cosmetic group three cases Table III. One case (No. 4) proved technic­ were aligned long-term. One regained fusion; ally impossible in that an EMG signal could one was a woman of 73. Eight cases have I10t be obtained so no toxin was administered. opted for maintenance therapy in the clinic as 454 J. LEE ET AL.

Table lIla 'Diplopic' group

Final Case Deviation Injections Compl deviatioll Olltcome

4. 50 R hypo Failure 50 R hypo Surgery RIRand LS R 5. 45 ET x4 LMR SCH 10 ET Continued BTXA-BSV 6. 25 XT xl RLR If)XP Fusion restored 7. 35 XT x2 LLR Small ET No BSV-discharged 9. 40 XT xl RLR SCH 40 XT No BSV-discharged 11. 18 ET xl LMR Straight Fusion restored 14 . 30 ET xl LMR ET/XT Variable fusion 16 . 35 XT xlLLR 8 ET No BSV-diseharged 18 . 45 XT xl RLR 10 XT Surgery RMRand RLR 20. 25 ET xl RMR Straight Fusion restored 27 . 43 XT xl RLR ET/XT Improved cosme sis

Table llIb 'Cosmetic' group

Final Case Deviation Injections Compl del'iotion Outcome

1. 20 RHT xl RS R Ptosis IORHT Later surgery 12 RXT xl RLR 8XT 2. 45 XT x13 LLR IOXT Maintenance--4 years 3. 40 XT x2 LLR 40XT No useful effect 8. 25 ET x4 RMR Small XT Maintenanee--4years 10 . 18 ET xlLMR Straight Discharged 12. 50 ET xl RMR Ptosis 30ET Later surgery 13 . 45 ET x6LMR 10 ET Maintenance-3 years 15 . 25 ET xl LM R ]()EP Fusion restored 17. 35XT x2 LLR 10 XT Improved 19. 20 ET xl LMR Ptosis 10 XT No useful effect 21. 45 XT x3 LLR 8XT Maintenance-l.S years 22. 25 ET x6 RMR ET/XT Maintenanee-l year Cyclic esotropia 23 . 18 XT x4 RMR ET/XT Maintenancc-l year 24. 60XT x3 RLR 20XT Maintenanee-lyear 25 . 35 XT x4 LLR ET/XT Maintenanee-lyear 26 . 35 ET xl LMR 4ET Surgery offered

Abbreviations: ET = Esotropia LR = Lateral rectus

XT = Exotropia SR = Superior rectus

HT = Hypertropia BSV = Binocular single vision

MR = Medial rectus SCH = Sub-conjunctival haemorrhage

an acceptable alternative to surgery. This last and the risk of extrusion or redetachment is group had typically poor visual acuity in the zero. Minimal discomfort is experienced and injected eye, large angles of and a the treatment may be repeated at will. We history of multiple detachment and strabis­ have found a high level of patient accept­ mus surgery. Their characteristics are shown ibility. Case 2 is a good example of this; he had in Table IV. a total of 13 injections to control a 45 prism In 19 of 31 patients, therefore, toxin treat­ exotropia over four years but ment provided some benefit. It should also be requested surgery as an alternative when he remembered that toxin therapy is particularly moved house and found attendance at the suitable for other reasons. Patients are toxin clinic inconvenient. treated as out-patients under local anaes­ ScottI" has recently reported his experience thesia and do not require admission or sur­ with Botulinum toxin in strabismus following gery. Explants are not disturbed or exposed retinal detachment surgery. He treated 20 TREATMENT OF STRABISMUS 455

Table IV Cosmetic maintenance group

Case Acuity Deviation Previous surgery Other features

2. 1/60 45 XT 2x retinal IOFB 8. H.M. 25 ET 2x retinal Traumatic lens dislocation Ix squint 13. 6/60 45 ET 5 x retinal Congo and schisis 21. H.M. 45 XT 2x retinal Traumatic cataract 22. N.P.L. 25 ET 1 x retinal Giant tear 23. P. L. 18 ET 3x retinal 2xsquint 24. 6/60 60 XT 2x retinal Bilateral giant tear 1 x squint 25. H.M. 35 XT 4x retinal Diabetic proliferative retinopathy patients, five of whom had more than one References I Portney GL. Campbell LH. Casebeer JC: Acquired detachment operation. Four of these five had heterotropia following surgery for retinal detach­ also had unsuccessful . ment. Am J OphthalmoI1972.73: 985-90. Vision was much better in his patients. , Kanski JJ. Elkington AR. Davies MS: Diplopia after Three had 6/60 vision and one had 3/60. All retinal detachment surgery. Am J Ophthalmol the remainder were better than this. He 1973.76: 38--40. 3 Sewell JJ, Knobloch WH, Eifrig DE: Extraocular obtained restoration of fusion and elimination after surgical treatment for ret­ of diplopia in 12 of 20 patients. Of the five inal detachment. Am J Ophthalmol 1974. 78: patients with persistent diplopia two were 321-3. cases of multiple retinal and strabismus sur­ , Price RL and Pederzolli A: Strabismus following ret­ gery and two had vertical deviations induced inal detachment surgery. Am Orthopt J1982, 32: by medial rectus injection. 9-17. 5 Waddell E: Retinal detachment and . Br One might speculate on the mechanism of Orthopt J1983. 40: 5-12. action in these cases. Usually at surgery these "Mcts MB, Wendell ME, Gieser RG: Ocular devia­ patients have extensive scarring and adhe­ tion after retinal detachment surgery. Am J sions, and may have positive forced duction Ophthalmol1985, 99: 667-72. 7 tests. Nevertheless, a reduction of the angle Smiddy WE. Loupe D, Michels RG, Enger C, Glaser BM. de Bustros S: Extraocular muscle can be seen following almost every injection. imbalance after scleral buckling surgery. Ophthal­ Clearly we must revise our concepts of the nwlogy 1989.96: 1485-90. underlying pathology in "restrictive' strabis­ H Fells P and Lce J: fol­ mus. The recent paper by Lyons and col­ lowing surgery for retinal detachment. Trans Eur leagues13 on the use of botulinum toxin in Strabmismol Assoc1984, 1984: 207-14. <) Fison PN and Chignell AH: Diplopia after retinal dysthyroid strabismus suggests that in some detachment surgery. Br J Ophthalmal1987, 71: cases of 'restrictive' strabismus an active 521-5. reversible contracture is taking place and that I() Wright KW: The fat adherence syndrome and stra­ it is this component which is affected by bot­ bismus after surgery. Ophthalmology1986, 93: 411-15. ulinum toxin therapy. I I Munoz M and Rosenbaum AL: Longterm strabis­ We conclude that intramuscular injection of mus complications following retinal detachment Botulinum toxin is a practicable management surgery. J Ped Ophthalmol and Strabism1987, 24: of strabismus following retinal detachment 309-14. surgery. It may make further strabismus sur­ "Scott AB: Botulinum treatment of strabismus fol­ gery unnecessary and may have particular lowing retinal detachment surgery. Arch Ophthal­ mol 1990. 108: 509-10. value in cosmetic maintenance therapy in 13 Lyons CJ, Vickers SF, Lee JP: Botulinum toxin ther­ younger patients with poor vision after com­ apy in dysthyroid strabismus. Eye 1990, 4: plex retinal surgery. 538--40.