Ocular motility disturbances after surgery for retinal detachment

Ocular Motility Disturbances After Surgery for Retinal Detachment V i n c e n z o M a u r i n o , M D , A n t h o n y K w a n , M B C h B , F R C O p h t h , B o o - M a n K h o o , MBBS, M i n e d , F R C S , E s t e r Gair, MBBS, F R C O p h t h , a n d J o h n P a t r i c k L e e , F R C S , F R C O p h t h , M R C P

Purpose: Relatively little has been published on the management of motility problems after surgery for retinal detachment. We report a large series with the aim of describing clinical features, management, and outcome. Methods:The charts of 68 of 86 consecutive patients referred to one of us between 1989 and 1995 were retrieved and analyzed. Sixty-two had unilateral and 6 bilateral surgery for retinal detachment. In 45 cases the macula was detached at surgery. The visual acuity of the affected eyes ranged from hand motions to 6/6. Sensory testing suggested potential binocular function in 39.7%. Fifty-nine patients had combined vertical and horizontal strabismus, 8 horizontal alone, and 1 vertical only. The average vertical deviation measured 10.2 PD and the average horizontal 19 PD. Results:Twelve patients underwent strabismus surgery, 26 were treated with botulinum toxin, 21 were managed conservatively with prisms or occlusion, and 8 refused or did not require treatment. Forty-seven percent of the group regained binocularity (20.5% cured with surgery or botulinum toxin, 26.5% controlled with prisms or intermittent injection with botulinum toxin). A total of 20.7% gained improvement in appearance, 19.1% were managed with permanent occlusion, and 13.2% either refused or did not require treatment. Conelu$ion:Macula off retinal detachment, poor visual acuity plus or minus distortion, and multiple procedures for retinal reattachment are associated with a poor prognosis for restoration of binocular vision and a good outcome. In our hands, botulinum toxin treatment is the method of choice, with surgery used in selected cases. (J AAPOS 1998;2:285-92)

etinal detachment surgery commonly causes disturbances of ocular motility, reported in 3 % to 14% of patients in retrospective series 1-4 and up to 73% in prospective studies, s-7 In most patients the problem is transient, but it may persist. 6 Attempts have been made to correlate the type and locality of the scleral buckling procedure with the subsequent motility defect.2, 4, 7, 8 There would seem to be a greater incidence of motility disturbances with cases treated with encirclement than sectorial explants, and also when repeated retinal detachment surgery is performed. The effect of poor visual acuity and macular distortion has not been studied. Relatively little has been published on the general management of this difficult condition. 9-14

R

SUBJECTS AND METHODS "We succeeded in retrieving the clinical notes of 68 of 86 consecutive patients referred to our motility clinic by the Prom MoorfieldsEye Hospital, London, United Kingdom. Presented at the annual meeting of the American Associationfor Pediatric Ophthalmology and Strabismus, Charleston, South Carolina, April 6, 199Z Submitted April 6, 199Z Revision acceptedFebruary 1O, 1998. Reprint requests:John Patrick Lee, FRCS, FRCOpbth, MRCP, Moooqelds Eye Hospital, City Road ECI V 2PD, London, United Kingdom. Copyright © 1998 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8831/98 $5.00 + 0 75/1/91572 Journal of AAPOS

vitreoretinal service between 1989 and 1995. All cases had undergone scleral buckling with or without vitrectomy in 1 or both eyes and had an interval of at least 9 months between the strabismus consultation and the last retinal reattachment operation. Concerning the 18 patients whose clinical charts were not found, we checked the botulinum and surgical database and found that approximately 60% had active treatment; these had a mean age of 56.7 and a male/female ratio similar to that of the other 68 patients. All patients had full preoperative and postoperative orthoptic evaluation that included binocular function assessment (Prism fusion range, Bagolini glasses, Synoptophore). RESULTS Patient Clinical Characteristics

Clinical characteristics are shown in Table 1. The male/female ratio was 39:29. The age range was from 18 to 85 years with a mean of 56.3 years. Six patients gave a history of preceding strabismus, and 4 of these had mild degrees of amblyopia. Seventy-four eyes of 68 patients had a total of 161 procedures, 102 sclera] buckles with or without vitrectomy, and 59 subsequent vitrectomies. The majority of patients had multiple retinal surgery, as shown in Table 2. October 1 9 9 8

28~

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Journal of AAPOS Volume 2 Number 5 October 1998

Maurino et al

TABLE 1. Patients' clinical characteristics,treatment, and outcome

Patient No.

Sex

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 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68

M M M F M M F M F M F M M F M M M M M F M M M M M F M F F F F F F M M M M M F F M F F M M F M F M F F M M M F F F F M M F M M F M F F M

Age (y) 66 42 73 30 67 70 64 30 31 52 56 31 22 66 57 70 60 32 60 69 53 66 72 41 68 22 21 62 64 50 63 60 57 51 24 35 56 85 64 58 72 67 74 60 53 62 48 75 85 67 18 67 55 54 60 71 71 65 73 68 76 44 59 57 56 67 22 67

Macula off Yes Yes No No No No No Yes Yes No Yes Yes Yes Yes Yes Yes Yes No Yes Yes No Yes Yes Yes No Yes No No No Yes Yes Yes Yes Yes Yes No No Yes Yes Yes Yes Yes Yes No No Yes No Yes Yes No Yes Yes Yes Yes Yes Yes Yes No Yes No Yes Yes Yes No Yes Yes No No

Main complaint Diplopia, distortion Cosmesis Cosmesis Cosmesis Diplopia Diplopia Diplopia Cosmesis Diplopia Diplopia Diplopia, cosmesis Diplopia Diplopia ,cosmesis Diplopia, cosmesis Oosmesis Diplopia, distortion Diplopia Diplopia Cosmesis Cosmesis Diplopia Diplopia, distortion Diplopia Diplopia Diplopia Cosmesis Diplopia Diplopia, cosmesis Diplopia, distortion Diplopia Diplopia, distortion Diplopia Diplopia, distortion Dipiopia Diplopia Diplopia Diplopia Dipropia, distortion Diplopia, distortion Diplopia, distortion Diplopia, cosmesis Diplopia, distortion Diplopia Diplopia, distortion Diplopia Diplopia Diplopia Diplopia Diplopia Diplopia Diplopia, cosmesis Diplopia Diplopia, distortion Diplopia, cosmesis Diplopia Diplopia Diplopia Diplopia Diplopia Diplopia Diplepia Cosmesis Diplopia Diplopia Diplopia, distortion Diplopia Diplopia 13iplopia

Type of retinal detachment surgery* 1 1 2 2+1 1+ 1 2 1 1 3 1 3 3 1 1 1 3 1 1 1+ 1 3 3 1+ 1 1 3 2 3 1 3 1 3 2 1 1 2 1 1 1 1 3 3 1 3+3 1 1 1 3 1 3 1 1 1 1 1 2 3 1 1 1 1 1 1 3 3+1 1 3 3 1 1

No. of retinal detachment procedures 1 2 1 4+1 1+3 1 1 4 1 2 3 3 4 3 3 2 1 1 I +2 4 2 2+ 1 2 3 4 1 1 4 1 2 4 2 1 1 1 2 1 2 3 5 .3 3+4 1 1 3 5 2 2 1 2 2 2 4 4 3 1 3 1 1 1 1 1 5+ 1 3 2 1 3 1

M, Male; Hyper, Hypertrp[oa; BTXA,botulinum toxin A; HM, hand movements vision; E female; Hypo,hypotropia. *Type of retinal detachment surgery: 1, local explant atone; 2, encircling band alone, 3, both horizontal angles; +, esotropia; -,exotropia

Distortion Yes No No No No No No No No Yes Yes No No Yes Yes Yes No No Yes No No Yes No Yes No No No No Yes No Yes Yes Yes No No No Yes Yes Yes Yes Yes Yes No Yes No Yes No No No No No No Yes No No No Yes No No No No No Yes No Yes No No No

Visual acuity of involved eye 6/60 HM 6/18 6/24 6/9 6/6 6/9 <6/60 6/24 6/12 6/60 6/36 6/18 6/24 2/60 4/60 6/18 6/24 3/60 3/60 6/24 6/24 6/60 6/18 6/18 PL 6/18 0.5/60 6/18 6/24 2/60 3/60 6/12 6/60 5/60 6/24 6/18 6/18 0.5/60 5/60 6/24 6/60 6/24 6/9 6/24 6/36 6/18 2/60 6/9 6/18 6/36 6/9 4/60 6/18 6/18 6/24 6/18 6/24 6/24 6/12 6/12 <6/60 6/18 6/60 6/36 6/12 6/9 " 6/5

Journal of AAPOS Volume 2 Number Y October 1998

Horizontal angle -20 -10 -10 +45 +12 -10 -6 -45 -16 -6 -55 -8 -4 +20 -45 -10 -6 -10 -35 -50 +4 +8 -8 -10 -6 -45 +14 -35 -16 -.35 -20 -8 -35 +15 +10 +8 +8 +8 -18 -65 -6 +47 -4 -15 -4 -9 -8 +4 -6 +16 -4O -30 +4 +70 +12 -2 0 -14 +6 -10 -25 -40 -7 -10 +12 -55 +14 -10

Vertical angle 3 Hyper 20 Hyper 14 Hyper 22 Hypo 4 Hyper 7 Hyper 25 Hypo 11 Hyper 11 Hyper 2 Hypo 5 Hypo 14 Hypo 36 Hypo 23 Hypo 8 Hypo 3 Hyper 2 Hyper 15 Hyper 8 Hyper O 10 Hypo 8 Hyper 36 Hypo 12 Hyper 4 Hyper 0 8 Hypo 12 Hyper 7 Hyper 13 Hyper 4 Hypo 3 Hyper 17 Hyper 0 13 Hyper 3 Hypo 18 Hypo 2 Hyper 7 Hyper 20 Hyper 18 Hypo 12 Hypo 7 Hyper 0 8 Hypo 18 Hyper 6 Hyper 4 Hyper 6 Hyper 5 Hyper 0 3 Hyper 0 0 12 Hyper 10 Hypo 16 Hyper O 7 Hyper 4 Hyper 0 12 Hypo 1 Hyper 16 Hypo 9 Hyper 7 Hypo 3 Hyper 5 Hyper

Maurino

Cyclotorsion

5 Excyclo 25 Incyclo

3 Excyclo

10 Incycle

11 Excyclo

Binocular function No ? Yes No ? Yes Yes No Yes Yes No No ? ? No No Yes Yes No ? Yes ? Yes No ? No No No ? Yes No No Yes Yes ? Yes ? ? No No ? ? No Yes Yes No ? No Yes Yes ? Yes ? No Yes Yes Yes Yes Yes Yes Yes No No ? ? No Yes Yes

Treatment BTXA Surgery Prism BTXA Prism Prism BTXA BTXA Surgery Prism BTXA Surgery BTXA BTXA Refused Prism Not needed Surgery BTXA BSXA BTXA Occlusion Surgery Occlusion Prism BTXA Refused BTXA Prism BTXA Occlusion Occlusion Surgery BTXA Surgery BTXA BTXA Prism Occlusion Refused BTXA BTXA Occlusion Not needed BTXA Refused Prism Occlusion Prism Surgery BTXA BTXA Prism BTXA Surgery BTXA Surgery Prism Prism Not needed BTXA BTXA Refused Surgery Occlusion Refused BTXA Surgery

Binocular function after treatment No No Yes No Yes Yes Yes No Yes Yes No No Yes No 0 No 0 Yes No Yes Yes No No No No No 0 No No No No No Yes Yes Yes Yes Yes Yes No 0 Yes No No 0 Yes 0 Yes No Yes Yes Yes Yes Yes No Yes Yes Yes Yes Yes 0 Yes No 0 Yes No 0 No Yes

Follow-up (mon) 5 4 4 34 10 4 15 19 14 27 24 48 52 6 0 6 10 25 60 13 15 2 10 4 4 9 2 8 6 9 O 0 24 12 12 3 14 40 0 0 24 6 14 0 2 0 16 1 13 16 10 11 3 23 8 13 9 10 10 0 12 12 0 26 0 O 10 10

287

Outcome Cosmetic improvement Cosmeticcontrolled Binocularitycontrolled Cosmetic improvement Binocularitycontrolled Binocularitycontrolled Cured Cosmetic improvement Cured Binocularitycontrolled Cosmetic improvement Cosmetic improvement Binocularitycontrolled Cosmetic improvement 0 Occlusiondistortion 0 Cured Cosmetic improvement Cured Binocularitycontrolled Occlusion distortion Occlusion Occlusion Occlusion Cosmetic improvement 0 Cosmetic improvement Occlusiondistortion Cosmetic improvement Occlusion Occlusion Cured Cured Cured Binocularitycontrolled Binocularitycontrolled Binocularitycontrolled Occlusion 0 Binocularitycontrolled Cosmetic improvement Occlusion 0 Binocularitycontrolled 0 Binocularitycontrolled Occlusion Binocularitycontrolled Cured Binocularitycontrolled Cured Binocularitycontrolled Cosmetic improvement Cured Binocularitycontrolled Cured Binocularitycontrolled Binocularitycontrolled 0 Cured Cosmetic im ~rovement 0 Cured Occlusion 0 Occlusion Cured

Journal ofAAPOS Volume 2 Number Y OctoberI998

288 Maurino el al TABLE 2. Number of retinal procedures

1 Procedure

2 Procedures

3 Procedures

4 Procedures

5 Procedures

30

17

14

10

3

TABLE 3. Visual acuity after retinal surgery

6/18 or better

6/24 to 6]60

Worse than 6/60

41.4%

35.2%

23.7%

TABLE 4, Surgical treatment

Patient No.

Horizontal angle (PD)*

Vertical angle (PD)

2

-10

20 Hypertropia

?

SR-

No

9

-16

11 Hypertropia

Yes

Yes

12

-8

14 Hypotropia

No

SR-, over corrected IR later SO-

18

-10

15 Hypertropia

Yes

23 33

-8 -35

36 Hypotropia 17 Hypertropia

Yes Yes

35 50 55 57

+10 +16 +12 0

? Yes Yes Yes

64 68

-10 -10

13 Hypertropia 5 Hyperphoria 12 Hypertropia 16 Intermittent hypertropia 16 Hypotropia 5 Hyperphoria

Binocular function

? Yes

Involved eye surgery1"

Fellow eye surgery

SO after tenotomy SO-, IRLR-, MR+, insertion down SRMR-, later SRMR-, SRSRIRSO after tenotomy

Horizontal Binocularity postalter operative surgery angle -12

Vertical postoperative angle 0

Followup (mon) 4

5 Hyper

14

Outcome Cosmetic improvement Cured

No

0

7 Hyper

48

Yes

-6

4 Hyper

25

Cosmetici mprovement Cured

No Yes

-15 +3

30 Hypo 2 Hyper

10 24

Occlusion Cured

Yes Yes Yes Yes

-5 -2 +1

2 Hypo 0 3 Hyper 3 Hyper

12 I6 8 9

Cured Cured Cured Cured

Yes Yes

+6 -10

O 3 Hyper

26 10

Cured Cured

SR, Superiorrectus; IR, inferior rectus;Hyper, hypertropia ; SO, superioroblique; Hypo, hypotropia;LR, lateral rectus; MR, medial rectus. %, Esotropia;-, exotropia. t+, Strengtheningprocedure;-, weakeningprocedure.

Encirclement procedures were performed in 28 eyes and local explants in 46. The macula was detached at time of surgery in 66.2%. Visual acuity of the affected eye (the poorer in bilateral cases) is shown in Table 3. VVhen first seen for strabismus evaluation, 58.8% complained of diplopia, 11.8% of cosmetic appearance, both the foregoing in 10.3%, and diplopia with distortion in 19.1%. Assessment of sensory potential was positive in 39.7%, doubtful in 26.5%, and negative in 33.8%. On direct questioning 36.7% were aware of distortion of central fixation in the affected eye. The deviation was vertical in 1 case, horizontal in 8 cases, and combined in 59, in all cases with clinically significant restriction of ocular rotations. Five cases also had cyclotorsional deviations (3 excyclo, 2 incyclo).

The average angle of horizontal deviation was 19 PD (exotropia 2 to 65 PD, exotropia 4 to 70 PD). The average angle of vertical deviation was 10.2 PD (2 to 36 PD). Treatment Twelve patients (17.6%) underwent strabismus surgery, on the affected eye in 10 cases and the fellow eye in 2. Details are given in Table 4. All rectus muscle procedures were with adjustable sutures. Follow-up was from 4 to 48 months with a mean of 17.2 months. Nine patients regained binocularity, 2 had improved cosmetic appearance, and 1 (case 23) had a poor outcome with recurrent hypotropia because of fat adherence syndrome and resorted to permanent occlusion. Twenty-six patients (38.2%) had botulinum toxin injections (Dysport, Speywood Pharmaceuticals, United

Journal of AAPOS Volume 2 Number Y October I998 TABLE 5. Botulinumtreatment Horizontal Patient angle Vertical No. (PD)* angle(PD)

Maurino

Binocular No. of function injections

Muscle injected

Binocularity after injection

Horizontal postinjection angle

Vertical postinjection angle

Followup (mon)

1

-20

3 Hyper

No

1

LR

No

-3

3 Hyper

5

4

+45

22 Hypo

No

8

MR

No

+16

16 Hypo

34

7 8

-6 -45

25 Hypo 11 Hyper

Yes No

1 7

IR LR

Yes No

-10 -14

7 Hypo 10 Hyper

15 19

11

-55

5 Hypo

No

4

LR

No

-15

13

-4

36 Hypo

?

10

IR

Yes

14

+20

23 Flypo

?

1

MR

No

-10

19

-35

8 Hyper

No

9

LR

No

-15

20 21

-50 +4

? Yes

1 3

LR IR

Yes Yes

-4

10 Hype

26

-45

No

3

LR

No

-16

9

28

-35

12 Hyper

No

3

LR

No

-20

8

30

-35

13 Hyper

Yes

1

LR

No

-12

34 36

+15 +8

3 Hypo

Yes Yes

1 2

MR MR

Yes Yes

+6 -4

37

+8

18 Hypo

?

3

IR

Yes

+2

6 Hypo

14

41

-6

18 Hypo

?

3

IR

Yes

-5

3 Hypo

24

42

+47

12 Hypo

?

1

MR

No

+7

1 Hypo

6

45

-4

8 Hypo

Yes

1

IR

Yes

-4

3 Hyper

2

51

-40

?

3

LR

Yes

-15

52 54

-30 +70

3 Hyper

Yes No

1 3

LR MR

Yes No

-5 +30

1 Hyper

11 23

56

-2

10 Hype

Yes

3

IR

Yes

-7

0

13

61 62

-25 -40

12 Hypo

Yes No

1 3

LR LR

Yes No

-15 -10

12 12

67

+14

3 Hyper

Yes

2

MR

No

3

10

24 8 Hypo

52

11 Hypo

6 60

R/L 4

3 Hyper

13 15

9 12 3

10

289

Outcome Cosmetic improvement Cosmetic improvement Cured Cosmetic improvement Cosmetic improvement Binocularity control led CosmetiC improvement Cosmetic improvement Cured Binocularity controlled Cosmetic improvement Cosmetic improvement + occlusion Cosmetic improvement Cured Binocularity controlled Binocularity controlled Binocularity controlled Cosmetic improvement Binocularity controlled Binocularity controlled Cured Cosmetic improvement Binocularity controlled Cured Cosmetic improvement Occlusion

Hyper, Hypertropia;LR, lateral rectus;Hypo, hypotropia;MR, medial rectus; IR, inferior rectus; R/L, either left hypotropiaor right hypertropia. %, Esotropia;-, exotropia.

Kingdom). Details are shown in Table 5. One case, ultimately treated surgically, had toxin as a first treatment with temporary improvement. Seventy-seven injections were given, with an average of 2.92 per patient. Twelve lateral, 7 medial, and 7 inferior recti were injected. Follow-up was

from 2 to 60 months with a mean of 16 months. Five cases were cured with follow-up of at least 11 months since the last injection. Eight have received repeated injections to maintain binocular single vision, and 11 have received repeated injections for cosmetic appearance. One patient

290

Maurino

et

Journal of AAPOS Volume 2 Number 5 October 1998

al

100 mVA>=6/18 I lVA<$11 n >:6160

65.2%

60%

IEIVA>6/SO $o,'1%

_N

[B encirclement+/- explant]

~%

37.7%

goodbinocular outcome

|lexplants a~one

poorbinocular outcome

I

Patientsnotact~e~y t ~ were excluded: Encirclement:14%, Expient:21.9%

macula on

~ c u | a off

FIG 3. Retinal detachment surgery versus final outcome. Good binocular outcome: fusion with or without small prisms. Poor binocular outcome: suppression or diplopia without fusion.

FIG 1. Visual acuity. B 6&2%

57,1%

57.5% b •

poor maculaon

maculaoff

Maculaon: 18.4%nottreated Maculaoff:.13,3%nottreated BF=Binonular Functions

FIG2. Final binocularityoutcome.

g<=2 RDops[ 1l>2 RD ops I

good

FIG 4. Binocular outcome. 6ood binocular outcome: fusion with or without small prisms. Poor binocular outcome: suppression or diplopia without fusion.

TABLE 6. Correlationof poor visual acuity or macular detachment with the developmentof postoperativestrabismus

Smiddy et al7 Maurino et al VA, Visualacuity.

Macular detachment

VA <6•60

61% 67%

26% 23.7%

improved cosmetically but then refused further treatment. One patient was found to have no binocular potential when straight and was given permanent occlusion. Twenty-one patients (30.9%) had conservative management. Thirteen tried prisms, 10 successfully and 3 reverting to occlusion. Eight had occlusion either of spectacle lenses or with contact lenses as a primary management• Nine patients (13.2%) either refused or did not require any treatment. Factors Affecting Hnal Outcome Binocular Vision. We evaluated our patients on first attendance for the potential for binocular vision by use of a variety of sensory tests. This was rated as positive in 27 cases (39.7%), dubious in 18 (26.5%), and absent in 23 (33.8%). "Positive" denoted the presence of fusion or simultaneous perception at all times when tested with prisms or synoptophore. "Dubious" denoted intermittent awareness of a cross on Bagolini glasses. "Absent" denoted no binocular response to any test. After completion of our treatment, 24 of 27 cases predicted to have binocular

No. of retinal procedures 86% 1, 14% 2 66% from 2 to 5

Distortion Not reported 46.6% Macula-off group

vision attained this. In the dubious group, 9 of 18 showed improved binocularity after treatment. None of the cases predicted to have no binocularity gained it after treatment. Central Distortion. Twenty-one of 45 patients with macular detachment (46.6%) had central distortion, whereas only 4 of 23 cases with macula on noted distortion (17.3%). Macular Detachment. Figure 1 shows the relative visual acuities in the macula-on and macula-off groups. The proportion of cases with poor central acuity is clearly greater in the macula-off group. Figure 2 shows the final binocular outcome in the 2 groups. Type of Scleral Buckling Procedure. Forty-one patients had 1 or more explants without encirclement, whereas 27 had an encircling band with or without other explants. Figure 3 shows the better final binocular outcome in the cases not treated with encirclement. N u m b e r of Retinal Reattachment Procedures. Figure 4 shows the binocular outcome in the group having 2 or fewer procedures versus those having 3 or more (on 1 or both eyes).

Journal ofAMPOS Volume 2 Number 5 October1998

DISCUSSION This study does not aim to address the incidence of strabismus or ocular restriction after retinal reattachment surgery. Our cases were recruited from referrals to us by a vitreoretinal service with a wide catchment area and a high proportion of tertiary referrals. Many of the cases that had multiple surgery had unsuccessful procedures elsewhere before referral to our hospital. It is notable that multiple surgery is associated with a poorer prognosis for restoration of binocular vision, and this has been noted by other authors,3, 4, 8 who have tended to relate the poorer outcome to surgical scarring and disordered ocular motility. Our data seem to suggest that poor central retinal function postoperatively acts as a barrier to restoration of binocularity in these cases. Several studies have shown that cases treated with encirclement have more postoperative ocular motility restriction. 4-7 In this series we have found the final binocular outcome to be worse in cases treated with encircling elements than in those treated with local scleral buckling. It is likely that such cases were either deemed to have more extensive detachment or that the encirclement was performed as part of a reoperation or vitrectomy procedure, so the observation is probably not of prognostic significance. We found a much poorer outcome when the macula was detached at some time in the period of retinal detachment, which has not been reported in previous studies, although it seems reasonable to assume that macular detachment would cause fusional problems. On the other hand, Smiddy et al 7 could not correlate poor visual acuity or macular detachment with the development of postoperative strabismus. Their data are compared with ours in Table 6. The main differences seem to be the number of retinal reattachment procedures and the awareness of distortion, which may be related.

Management of Motility Problems We have tended to offer most patients bomlinum toxin as a first-line therapy. Twenty-seven patients were treated in this way, 1 ultimately opting for surgical treatment. We and others 13-15have reported the advantages of this form of therapy, the greatest advantage being extreme ease of treatment compared with surgery. Five patients were "cured," with restoration of binocularity over a follow-up period of at least 11 months after the last injection. This is analogous to similar functional cure achieved with toxin alone in sixth nerve palsy16 and other types of acquired strabismus. 17 Such cases tend to show good individual visual acuity, binocular vision potential, and small strabismus angles. The restoration of binocularity in what has often been seen as a "restrictive" disease process is similar to that reported in early dysthyroid eye disease) 8 We also tended to advocate toxin treatment where vision was poor or distorted or where binocularity was uncertain, on the grounds that temporary realignment might give data regarding long-term management. Twelve patients received corrective strabismus surgery. One case was treated to improve appearance, the others

Maurino

291

for diplopia. Table 4 shows the results. Nine of 12 patients regained binocularity. All had relatively good acuity and predicted binocular potential on preoperative testing. Six of 9 vertical recti were superior recti. The first line of treatment in our hands is usually botulinum toxin, but where the eye is hypertropic we feel that injection of superior rectus is likely to produce a significant ptosis, so we tend to favour surgery in such cases. Adjustable sutures were used routinely. One case (patient 23) had a poor result because of fat adherence syndrome. Various authors have described this surgical complication after strabismus surgery and retinal surgery. 12, 19 Five of our patients had cyclotorsional strabismus, in all c~ises associated with horizontal or vertical deviations. Three, with macula-off detachment, distortion, and no potential binocular function, were treated with occlusion. One was controlled with a tilted prism. The fifth, who also had vertical diplopia, was cured by inferior rectus surgery. The exact incidence of cyclotorsional strabismus is difficult to assess and may be related to retinal surgery involving the oblique muscles and inferior recti. 20, 21 The remaining cases were managed conservatively. Ten of 13 patients managed initially with Fresnel prisms found this a satisfactory long-term treatment and continued with built-in prisms in spectacles. All had small strabismus angles and good binocular function. Eight patients were offered permanent occlusion from the first assessment. All had poor binocularity and central visual distortion. A further 5 patients were initially tried on botulinum toxin but were found to have no potential for binocular function so were managed with occlusion. Five patients declined any other therapy, 1 having first tried the effect of botulinum toxin. All had no discernible potential for restoration of binocular vision. Finally, 3 referred patients had symptoms that could be relieved by refraction and spectacle correction, and no further treatment was required. We conclude that cases referred by our retinal surgical colleagues are a diverse group, with very variable potential for the restoration of binocular vision. Maeula-off retinal detachment, poor visual acuity, central visual distortion, and multiple retinal reattachment surgery are probably all interrelated and are associated with a poorer prognosis for binocular vision. Our preferred firstqine treatment is botulinum toxin injection, with surgery preferred where a hypertropia requires treatment or where fellow-eye surgery is indicated. Overall, 47% of patients regained binocular vision (20.5% cured with surgery or toxin, 26.5% controlled with prisms or long-term toxin), 20% were improved cosmetically, 19.1% had permanent occlusion, and 13.2% either refused or did not require treatment.

References 1. PormeyGL, CampbellLH, CasebeerJC.Acquiredheterotropiafollowing surgery for retinal detachment. Am J Ophthalmol 1972; 73:985-90.

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2. Kanski JJ, Elkington AR, Davies MS. Diplopia after retinal detachment surgery. AmJ Ophthalmol 1973;76:38-40. 3. SewellJJ, K.noblochWH, Eifrig DDE. Extraocular muscle imbalance after surgery for retinal detachment. AmJ Ophthalmol 1974;78:321-3. 4. Price RL, Pederzolli A. Strabismus following retinal detachment surgery. Am OrthoptJ 1982;32:9-17 5. Waddell E. Retinal detachment and orthoptics. Br Orthopt J 1983;40:5-12. 6. Metz MB, Wendell ME, Gieser RG. Ocular deviation after retinal detachment surgery. Am J Ophthalmol 1985;99:667-672 7. Smiddy WE, Loupe D, Michels RG, Henger H, Glaser BM, de Bustros S. Extraocular muscle imbalance after scleral bucHing surgery. Ophthalmology 1989;96:1485-9. 8. Spencer AF, Newton C, Vernon SA. Incidence of ocular motility problems following scleral buckling surgery. Eye 1993;7:751-6. 9. Munoz M, Rosembaum AL. Long term strabismus complications following retinal detachment surgery. J Pediatr Ophthalmol Strabismus 1987;24:309-14. 10. Fison PN, Chignell AH. Diplopia after retinal detachment surgery. BrJ Ophthalmol 1987;71:521-5. 11. Fells P, Lee J. Management of strabismus following surgery for retinal detachment. Trans Eur Strabismol Assoc 1984;207-14.

Journal of AAPOS Volume 2 Number 5 October 1998 12. Wright KW. The fat adherence syndrome and strabismus after retinal surgery. Ophthalmology 1986;93:411-5. 13. Scott AB. Botulinum treatment of strabismus following retinal detachment surgery. Arch Ophthalmol 1990;108:509-10. 14. Lee J, Page B, LiptonJ. Treatment of strabismus after retinal detachment surgery with botulinum neurotoxin A. Eye 1991;5:451-5. 15. Petitto BV,,Buckley EG. Use of botulimtm toxin in strabismus after retinal detachment surgery. Ophthalmology 1991;98:509-12 16. Lee JP. Modern management of VI nerve palsy. Aust N Z J Ophthalmol 1990;20:41-6. 17. Balakrishnan V,, Maurino V,, Lymburn E, MaEwen C, Lee JP. "Functional cure" with botulinum toxin treatment. In Spirit-us M, editor. Transactions of the 22nd ESA meeting. Cambridge: Aelus Press; 1995. p. 232-7. ! 8. Lyons CJ, V]ckers SiC,Lee JP. Botulinum toxin therapy in dysthyroid strabismus. Eye 1990;4:583-40. 19. Parks MM. The overacting inferior oblique muscle. Am J Ophthalmol 1974;77:787-972. 20. Arruga A. Binocularity after retinal detachment surgery. Doc Ophthalmol 1973;34:41-5. 2 I. Metz HS, Norris A. Cyclotorsional diplopia following retinal detachment surgery. J Pediatr Ophthalmol Strabismus 1987;24:287-90.