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Botulinum Alignment for Congenital Esotropia
Botulinum Alignment for Congenital Esotropia Malcolm R. lng, MD Background: Botulinum toxin injection into the medial rectus has been recommended by several investigators as an alternative to incisional surgery for treatment of patients with congenital (essential infantile) esotropia. Currently, there are no published studies demonstrating both the motor and sensory results of congenital esotropic patients aligned by botulinum toxin. Methods: The author traveled to two medical centers to personally and objectively examine, with standardized testing methods, 12 patients with congenital esotropia who had been aligned for a minimum of 6 months by the age of 2 years by other investigators. The selected patients had been followed for a minimum of 3 years and were of sufficient maturity to reliably respond to sensory testing. A comparison was made between the author's conclusions about the binocularity results of these patients and the assessment of the treating ophthalmologists. Results: Only 6 of the 12 patients demonstrated optimum motor alignment to within 10 prism diopters (PD) of orthophoria at the time of the study. A minimum of 1-month (average, 5 months) post-botulinum injection was found to be necessary to establish this alignment. Only three of these six aligned patients could both fuse and demonstrate gross stereopsis without the assistance of compensatory prisms. These results can be contrasted to a previously reported group of surgically aligned cases in which 66 of 90 patients aligned by 2 years of age could both fuse and demonstrate stereopsis, without any use of compensatory prisms. Conclusion: These results must be considered preliminary. However, alignment by botulinum appears to be less effective in establishing evidence for binocularity than incisional surgery in the treatment of congenital esotropia (P < 0.001). Ophthalmology 1993; 100: 318-322
The ingenious discovery of chemodenervation by dilute injections of botulinum A toxin to alter ocular muscle alignment in humans was first reported by Scotti in 1980. Since that report, however, there have been only a few articles on the use of the toxin in childhood strabismus. 2 - 4 Scott et al 5 reported 66% of infantile esotropic patients achieved alignment of within 10 prism diopters (PO) of orthophoria with slightly over 2 years of followup. These authors considered their alignment results to be comparable with results by some authors using inci-
Originally received: August 3, 1992. Revision accepted: September 28, 1992. Presented at the Annual Meeting of the American Ophthalmological Society. Hot Springs, Virginia, May 1992. Reprint requests to Malcolm R. lng, MD, 1319 Punahou St, Suite 1110, Honolulu, HA 96826-1074.
318
sional surgery. Other investigators using incisional surgery, however, have reported the more efficient results oflarger amounts of surgery to alter large angle infantile esotropia. 6- 10 Furthermore, in a study comparing botulinum toxin with surgical treatment, Biglan et alii concluded that chemodenervation was not as successful as traditional strabismus surgery for the treatment of infantile esotropia. These authors reported 4 of 12 infants could be successfully aligned, but they concluded that ophthalmologists could achieve a better rate of correction in 1 week with surgery rather than waiting the multiple weeks of fluctuating alignment required after botulinum injections. In addition to the controversy concerning the efficiency of botulinum to secure satisfactory motor alignment, it has been pointed out by Hague and Lee l2 that the results of sensory testing in patients with botulinum-aligned congenital esotropia have not been reported. The purpose of this article is to report an independent study of the motor alignment and results of sensory testing
I ng . Botulinum Alignment for Congenital Esotropia in a group of patients with congenital (essential i~fantile) esotropia aligned to within 10 PD of orthophona for at least 6 months and observed for at least 3 years.
Patients and Methods Using the same techniques that determine the results of . I esotropia, . 13 an 0 bearly surgical alignment for congemta jective study of patients with congenital esotropia aligned by botulinum injection was conducted at two centers. Surgeons were asked to select patients who fulfil.led the following requirements: (1) a history of esotropIa confirmed by an ophthalmologist's examination by 1 year of age, (2) alignment to within 10 PD of orthophoria for a minimum of 6 months by botulinum injection alone by 2 years of age, and (3) sufficient maturity to re!iably respond to sensory testing. Patients with neurologIc abn,ormali ties were excluded. The author visited the centers to examine the patients; these were patients of ophthalmologists who had extensive experience using botulinum for strabismus. This investigator performed the examinations on all the patients for the study before reviewing the clinical record. The tests and identical testing instruments were uniformly performed on all patients. The corrected Snellen visual acuity was obtained. Cover testing was performed with strict accommodation control techniques that included wearing full refractive correction and fixating 20/30 letter targets at distance and near. Various cover tests included the cover-uncover test, simultaneous prism and cover test, and alternating cover test. Versions were tested, including an examination for A- or V-patterns. Sensory testing was performed with (1) Bagolini-striated glasses with fixati~:m light at one-third meter, (2) Worth 4 dots at one-thIrd meter with larger (macro) conventional dots and smaller (micro) dots, and (3) Polaroid Titmus vectographic stereotest (Stereo Optical, Inc, Chicago, IL). At the end of the motor and sensory tests, the patient's clinical record was examined and abstracted, with emphasis on obtaining the following data: (1) age at onset by history; (2) first confirmation of the esotropia by an ophthalmologist; (3) initial cycloplegic retinos.cop?;. ~4) initial measurements with prisms; (5) age at whIch Imtial alignment to within 10 PD of orthophoria h~d ~een achieved for a minimum of 6 months; (6) comphcatIOns such as transient blepharoptosis; (7) adjunctive measures such as occlusion, glasses, miotics, and prisms; and (8) the impression of the patient's own ophthalmologist regarding the status of the binocularity at least some time during the post-injection course. After examining the compiled histories, further refinement was attempted to identify patients with acquired or accommodative esotropia because these patients would be eliminated from the study.
Results For the purposes of comparison, the patients are presented in Table 2 in ascending order of age of alignment by bot-
ulinum injection. Six boys and six girls were included in the study. Case 13, although presented in the table, was eliminated from the analysis because he received his initial examination at 3 years of age and was judged to be a patient with acquired esotropia. The age of examination for this study ranged from 4 to 7 years (average, 6 years). The ages of confirmation of the congenital nature of the strabismus ranged from 3 to 11 months (average, 5.9 months). Initial refractive errors included one patient with myopia and 11 with hyperopia ranging from 0.25 to 8 diopters (D) (average, 2.2 D). The initial deviation as determined by the treating ophthalmologist ranged from 20 to 70 PD (average, 41 PD). The youngest patient receiving initial medial rectus injection was 4 months of age, and the oldest was 1 year and 9 months of age. The average age of initial treatment was 7.7 months for the entire group. The age at which satisfactory alignment was achieved, however, ranged from 7 months to 1 year and 11 months (average, 13 months). Therefore, there was a significant lag time between initial treatment and alignment, ranging from 1 to 18 months (case 12) (average, 5 months). There was a correlation of the number of medial recti injections to reach alignment by the time of the study with the quantity of the initial deviation (Table 1). The motor alignment at the time of the study ranged from zero deviation to 30 PD of esotropia. Six of the patients had 10 PD or less of residual deviation. However, 6 of the 12 patients were wearing base-out prisms of a total of 4 to 8 PD to help neutralize the residual deviation. Transient unilateral blepharoptosis after medial rectus chemodenervation was a common occurrence and was found in 8 of the 12 patients. Nevertheless, this complication did not seem to preclude satisfactory alignment or the ability to demonstrate subsequent binocularity on sensory testing. A binocular response with Bagolini-striated glasses was found in 10 of 12 patients examined for sensory evidence of binocularity. The conventional-sized (macro) Worth 4 dots were fused by 6 of 12 patients. However, only one patient was able to fuse the smaller (micro) dots as well as the larger ones demonstrating a relatively large scotoma in the majorit; of the patients who were capable of fu~ion. . It should be noted that, because two prevIOUS studIes Table 1. Correlation of Initial Deviation and Number of Medial Recti Injections Deviation (PD)
No. of Injections
Case No.
20-30
2
2,6, 11, and 12
35
2or3
40-60
3
8, 10 3,4, 5, 7, and 9
70
4
1
PD
=
prism diopters.
319
N
"'a"
4:0
7:0
5:6
6:10
4:10
6:2
6:11
10:0
6
7
8
9
10
11
12
13
~
3:0
6:7
5
prism diopters; ET
0:4
6:11
4
PD
0:10
6:6
3
esotropia; RMR
~
3:11 3:11
0:5 0:10 1:3
1:5
1:3
0:7 0:11 1:8
1:1 2:0
1:1
1:2
1:2
0:6 0:7
0:5 0:8
0:7 0:7 2:0
0:7 0:8 1:8
0:6 1:9 4:11
0:4 2:1
0:4 0:4 0:6 2:2
At Injection
4:2
1:11
1:9
1:9
1:4
1:3
1:1
1:0
0:8
~
20/60 20/40
20/30 20/30
20/25
20/25
20/70 20/100
20/40
20/30
20/30 20/30
20/70 20/30
20/30 20/30
20/200 20/30
20/25 20/30
20/30 20/30
20/30 20/30
20/25 20/25
Visual Acuity
Current
o
ETcc 4 ET' cc 4
ITa~
ETa 20
ITa~IT~
DVD
ETalO-~
EX cc 0 EX' cc 0
ET cv 10 - 25, DVD ET' cc 10 - 14, DVD' (Apattern)
XT cc 4, DVD XT' cc 10, DVD'
ET cc 16 - 20 ET' cc 16 - 20
ET cc 8 - 16 ET' cc 20
ET cc 15, DVD ET' cc 15
ET cc 25 ET' cc 16
ET cc 12 ET' cc 14, DVD'
ET c 12 ET' cc 20, ET' bif 10
DVD DVD'
Alignment Distance and Near
Current
~
Binoe
Alt
Binoe
Binoe
Binoe
Alt
Binoe
Binoe
Binoe
Binoe
Binoe
Binoe
Binoe
Striated Glasses
alternating.
Ptosis myopic
prisms
Ptosis
Ptosis
Ptosis
A-pattern
prisms
Ptosis
prisms
Ptosis
prisms
Ptosis
nystagmus prisms
Latent
prisms
Ptosis
prisms
Ptosis
Myopic
Comments
dissociated vertical divergence; Binoe = binocular; Alt
0:3
1:6
0:6
1:2
0:3
0:1
0:7
0:7
0:1
0:1
0:1
0:7
0:8
0:3
0:3
Lag Time (yrs:mos)
0:7
0:7
Initial Adequate Alignment
Age (yrs:mos)
left medial rectus; DVD
RMR 1.25 LMR 1.25
RMR 1.25 LMR2.5 LMR 5.0
LMR 3.7
right medial rectus; LMR
ET 10
-9.00 -9.00 ~
ET 25
+0.50 +0.50
o
RMR2.5
+0.25
0:9 ET 25
RMR2.5 LMR5.0 LMR 10
ET 35
+2.00 +1.50
RMR2.5
RMR 2.5 LMR2.5
0:6
ET40
ET 35
RMR 1.25 LMR 2.5
LMR 2.5 RMR2.5
ET 20 ET60
RMR 1.5 LMR 3.75 RMR5.0
LMR 1.25 RMR3.75 RMR6.25
RMR 2.5 LMR5.0 LMR5.0
LMR2.5 LMR 2.5
RMR 1.25 LMR 2.5 RMR2.5 LMR5.0
Injection Dose (units)
ET60
ET 50
ET45
ET 30
ET70
Initial Deviation (PD)
LMR2.5 RMR2.5
+7.87
+0.37 +0.50
+3.00 +2.50
+3.25 +3.87
+3.00 +2.50
+1.50 +1.50
+1.75 +2.00
+1.50 +1.50
-1.00 -1.00
Initial Refraction (spherical equivalent)
+8.00
0:11
0:5
0:3
0:3
0:7
0:6
5:2
~
0:3
6:4
0:4
First Diagnosed by Ophthalmologist
At Examination
2
Case No.
Age (yrs:mos)
Table 2. Clinical Characteristics
None
+/-
+/-
None
None
None
-/-
-/-
3000
3000
+/-
+/-
None
3000
+/+ -/-
None
None
400
-/-
-/-
+/-
3000
3000
+/-
-/-
Stereo Acuity (sec. of arc)
Worth 4 Dot Macro/ Micro
+ +
+ +
+
+
+
+
+
+
+
+
+
;j
+
~
......
;:r'
C")
~ -l
~
-"'"
-l
(t>
0-'
~
z
E
......
(t>
~ ;j
~
~
0"
o
§"
g:
o
'0
+
+
+
+
+
+
Own Physician
This Examination
Evidence for Binocularity
I ng . Botulinum Alignment for Congenital Esotropia have shown that fusional amplitudes with a major amblyoscope were universally found in patients who could fuse Worth 4 dots, the use of the major amblyoscope was believed to be redundant and not necessary for the current study.14,15 Five patients who fused also had stereopsis. One patient had stereopsis but no fusion. All of these patients showed only gross stereoacuity. A motor deviation of 10 PO or less at near-fixation point and the ability to fuse Worth 4 dots and demonstrate stereopsis were found in only 3 of the 12 patients (cases 1,9, and 10) studied. Only those three patients, therefore, were able to show an "optimum" binocular result. There were, however, an additional two patients (cases 4 and 7), wearing base-out prisms up to a total of eight to neutralize residual motor deviation over 10 PO, who were able to show sensory fusion and stereopsis. The results in these latter two patients were not included as optimum because of the presumed dependence on prisms to show sensory evidence of binocularity. A comparison can be made between this investigator's opinion and with the opinions of the original ophthalmologists. Eleven of the 12 patients were thought by the patient's own ophthalmologist to have binocularity. However, using the motor and sensory tests described above, this investigator determined that only three patients had findings considered optimum for the treatment of congenital esotropia.
Discussion In his discussion of the results of botulinum treatment for childhood strabismus, Von Noorden l6 proposed that a scientific comparison of chemodenervation and surgical alignment could only be achieved in a prospective randomized study. As previously noted, however, the age of alignment does not necessarily coincide with the age of first surgery,13 a fact that precludes any meaningful prospective study. Furthermore, as shown in this study, the age of satisfactory alignment lagged behind the age of initial injection by an average of 5 months. Therefore, a retrospective study of cases adequately aligned by botulinum would probably still be the best available database from which to derive conclusions concerning the efficacy of the chemodenervation technique. The results of the current study demonstrate conclusively that binocular vision, despite being described as subnormal by von Noorden,17 is possible in some of the botulinum-aligned patients if this alignment is secured by 2 years of age for a minimum of 6 months. Prior studies have shown that sensory testing is a necessary component of an investigation of binocularity because a patient may have relatively straight eyes but no binocularity on sensory testing (e.g., case 8).13 The resultant motor alignment in the botulinumtreated group showed that approximately 25% (3 of 12) could achieve 10 PO or less of residual misalignment and demonstrate fusion and stereopsis. An additional four patients (cases 2,3,8, and 11) achieved a near alignment of 10 PO or less, but none of these same patients could dem-
on strate both fusion and stereopsis. In addition, two of these patients did not even show a binocular response to the most rudimentary test-Bagolini-striated glasses. The current relatively small group of intensely studied botulinum-aligned subjects can be contrasted to a larger, slightly older group (average age, 9.5 years) of surgically aligned subjects studied in an identical manner by this investigator. 13 Of the 90 patients aligned surgically, 80 (88%) achieved the alignment to within 10 PO of orthophoria within 1 week of surgical treatment. Therefore, the efficiency of surgical treatment was greater than that of the botulinum-treated group, which averaged 5 months after initial injection to achieve alignment. This occurrence of delayed alignment with botulinum was even more notable, in that the botulinum-treated group averaged less deviation (41 PO) when compared with the more typical quantity (57 PO) found in the surgically treated group. Undoubtedly, the multiple injections necessary to treat the patients with greater deviations led to further delay in achieving satisfactory alignment. Additionally, eyes of only three patients of the botulinum-treated group straightened to within 10 PO of orthophoria without compensatory prisms and had both fusion and gross stereopsis in contrast to 66 of the 90 surgically aligned subjects who were able to do so without prisms. 13 Although the size of the current study group is small, it should be pointed out that these patients were selected as the best cases by the other investigators, and they were intensively studied. Botulinum treatment appears to be less effective than surgical treatment for establishing binocularity in congenital esotropia. There is a statistically significant difference in the outcome of the same tests between the two groups (chi-square 11.302; P < 0.001; ds = 1).
Acknowledgment The author thanks Drs. Alan Scott and Elbert Magoon, without whose patient referrals this study could not have been completed,
References 1. Scott AB. Botulinum toxin injection into extraocular muscles as an alternative to strabismus surgery. Ophthalmology 1980;87: 1044-9. 2. Magoon E, Scott AB. Botulinum toxin chemodenervation in infants and children: an alternative to incisional strabismus surgery. J Pediatr 1987; 110:719-22. 3. Scott AB. Botulinum injection treatment of congenital esotropia, In: Lenk-Schafer M, ed. Orthoptic Horizons: Trans Sixth Int'l Orthoptic Congress. London: British Orthoptic Society, 1988;294-9. 4. Magoon EH. Chemodenervation of strabismic children. A 2- to 5-year follow-up study compared with shorter followup. Ophthalmology 1989;96:931-4. 5. Scott AB, Magoon EH, McNeer KW, Stager DR. Botulinum treatment of childhood strabismus. Ophthalmology 1990;97: 1434-8. 6. Helveston EM, Ellis FD, Schott J, et al. Surgical treatment of congenital esotropia. Am J Ophthalmol 1983;96:218-28. 7. Kushner BJ, Morton GV. A randomized comparison of surgical procedures for infantile esotropia. Am J Ophthalmol 1984;98:50-61.
321
Ophthalmology
Volume 100, Number 3, March 1993
8. Mims JL III, TreffG, Kincaid M, et al. Quantitative surgical guidelines for bimedial recession for infantile esotropia. Binocular Vis 1985;1:7-22. 9. Bartley GB, Dyer JA, Ilstrup DM. Characteristics ofrecession-resection and bimedial recession for childhood esotropia. Arch Ophthalmol 1985; 103: 190-5. 10. Scott WE, Reese PD, Hirsh CR, Rabetich CA. Surgery for large-angle congenital esotropia. Two vs three and four horizontal muscles. Arch OphthalmoI1986;104:374-7. II. Biglan AW, Burnstine RA, Rogers GL, Saunders RA. Management of strabismus with botulinum A toxin. Ophthalmology 1989;96:935-43. 12. Hague S, Lee JP. Botulinum toxin: an alternative to squint surgery in childhood? In: Campos EC, ed. Strabismus and Ocular Motility Disorders: Proc Sixth Meeting of the Inri
322
13. 14. 15. 16.
17.
Strabismological Association. Houndmills: Macmillan, 1991 ;413-20. Ing MR. Early surgical alignment for congenital esotropia. Trans Am Ophthalmol Soc 1981 ;79:625-63. Ing M, Costenbader FD, Parks MM, Albert DG. Early surgery for congenital esotropia. Am J Ophthalmol 1966;61: 1419-27. Parks MM. The monofixation syndrome. Trans Am Ophthalmol Soc 1969;67:609-57. von Noorden G. Discussion, 180-1. Of: Scott AB, Magoon EH, McNeer K, Stager DR. Botulinum treatment of strabismus in children. Trans Am Ophthalmol Soc 1989;87: 174-84. von Noorden GK. A reassessment of infantile esotropia. XLIV Edward Jackson Memorial Lecture. Am J Ophthalmol 1988;105:1-10.
The ingenious discovery of chemodenervation by dilute injections of botulinum A toxin to alter ocular muscle alignment in humans was first reported by Scotti in 1980. Since that report, however, there have been only a few articles on the use of the toxin in childhood strabismus. 2 - 4 Scott et al 5 reported 66% of infantile esotropic patients achieved alignment of within 10 prism diopters (PO) of orthophoria with slightly over 2 years of followup. These authors considered their alignment results to be comparable with results by some authors using inci-
Originally received: August 3, 1992. Revision accepted: September 28, 1992. Presented at the Annual Meeting of the American Ophthalmological Society. Hot Springs, Virginia, May 1992. Reprint requests to Malcolm R. lng, MD, 1319 Punahou St, Suite 1110, Honolulu, HA 96826-1074.
318
sional surgery. Other investigators using incisional surgery, however, have reported the more efficient results oflarger amounts of surgery to alter large angle infantile esotropia. 6- 10 Furthermore, in a study comparing botulinum toxin with surgical treatment, Biglan et alii concluded that chemodenervation was not as successful as traditional strabismus surgery for the treatment of infantile esotropia. These authors reported 4 of 12 infants could be successfully aligned, but they concluded that ophthalmologists could achieve a better rate of correction in 1 week with surgery rather than waiting the multiple weeks of fluctuating alignment required after botulinum injections. In addition to the controversy concerning the efficiency of botulinum to secure satisfactory motor alignment, it has been pointed out by Hague and Lee l2 that the results of sensory testing in patients with botulinum-aligned congenital esotropia have not been reported. The purpose of this article is to report an independent study of the motor alignment and results of sensory testing
I ng . Botulinum Alignment for Congenital Esotropia in a group of patients with congenital (essential i~fantile) esotropia aligned to within 10 PD of orthophona for at least 6 months and observed for at least 3 years.
Patients and Methods Using the same techniques that determine the results of . I esotropia, . 13 an 0 bearly surgical alignment for congemta jective study of patients with congenital esotropia aligned by botulinum injection was conducted at two centers. Surgeons were asked to select patients who fulfil.led the following requirements: (1) a history of esotropIa confirmed by an ophthalmologist's examination by 1 year of age, (2) alignment to within 10 PD of orthophoria for a minimum of 6 months by botulinum injection alone by 2 years of age, and (3) sufficient maturity to re!iably respond to sensory testing. Patients with neurologIc abn,ormali ties were excluded. The author visited the centers to examine the patients; these were patients of ophthalmologists who had extensive experience using botulinum for strabismus. This investigator performed the examinations on all the patients for the study before reviewing the clinical record. The tests and identical testing instruments were uniformly performed on all patients. The corrected Snellen visual acuity was obtained. Cover testing was performed with strict accommodation control techniques that included wearing full refractive correction and fixating 20/30 letter targets at distance and near. Various cover tests included the cover-uncover test, simultaneous prism and cover test, and alternating cover test. Versions were tested, including an examination for A- or V-patterns. Sensory testing was performed with (1) Bagolini-striated glasses with fixati~:m light at one-third meter, (2) Worth 4 dots at one-thIrd meter with larger (macro) conventional dots and smaller (micro) dots, and (3) Polaroid Titmus vectographic stereotest (Stereo Optical, Inc, Chicago, IL). At the end of the motor and sensory tests, the patient's clinical record was examined and abstracted, with emphasis on obtaining the following data: (1) age at onset by history; (2) first confirmation of the esotropia by an ophthalmologist; (3) initial cycloplegic retinos.cop?;. ~4) initial measurements with prisms; (5) age at whIch Imtial alignment to within 10 PD of orthophoria h~d ~een achieved for a minimum of 6 months; (6) comphcatIOns such as transient blepharoptosis; (7) adjunctive measures such as occlusion, glasses, miotics, and prisms; and (8) the impression of the patient's own ophthalmologist regarding the status of the binocularity at least some time during the post-injection course. After examining the compiled histories, further refinement was attempted to identify patients with acquired or accommodative esotropia because these patients would be eliminated from the study.
Results For the purposes of comparison, the patients are presented in Table 2 in ascending order of age of alignment by bot-
ulinum injection. Six boys and six girls were included in the study. Case 13, although presented in the table, was eliminated from the analysis because he received his initial examination at 3 years of age and was judged to be a patient with acquired esotropia. The age of examination for this study ranged from 4 to 7 years (average, 6 years). The ages of confirmation of the congenital nature of the strabismus ranged from 3 to 11 months (average, 5.9 months). Initial refractive errors included one patient with myopia and 11 with hyperopia ranging from 0.25 to 8 diopters (D) (average, 2.2 D). The initial deviation as determined by the treating ophthalmologist ranged from 20 to 70 PD (average, 41 PD). The youngest patient receiving initial medial rectus injection was 4 months of age, and the oldest was 1 year and 9 months of age. The average age of initial treatment was 7.7 months for the entire group. The age at which satisfactory alignment was achieved, however, ranged from 7 months to 1 year and 11 months (average, 13 months). Therefore, there was a significant lag time between initial treatment and alignment, ranging from 1 to 18 months (case 12) (average, 5 months). There was a correlation of the number of medial recti injections to reach alignment by the time of the study with the quantity of the initial deviation (Table 1). The motor alignment at the time of the study ranged from zero deviation to 30 PD of esotropia. Six of the patients had 10 PD or less of residual deviation. However, 6 of the 12 patients were wearing base-out prisms of a total of 4 to 8 PD to help neutralize the residual deviation. Transient unilateral blepharoptosis after medial rectus chemodenervation was a common occurrence and was found in 8 of the 12 patients. Nevertheless, this complication did not seem to preclude satisfactory alignment or the ability to demonstrate subsequent binocularity on sensory testing. A binocular response with Bagolini-striated glasses was found in 10 of 12 patients examined for sensory evidence of binocularity. The conventional-sized (macro) Worth 4 dots were fused by 6 of 12 patients. However, only one patient was able to fuse the smaller (micro) dots as well as the larger ones demonstrating a relatively large scotoma in the majorit; of the patients who were capable of fu~ion. . It should be noted that, because two prevIOUS studIes Table 1. Correlation of Initial Deviation and Number of Medial Recti Injections Deviation (PD)
No. of Injections
Case No.
20-30
2
2,6, 11, and 12
35
2or3
40-60
3
8, 10 3,4, 5, 7, and 9
70
4
1
PD
=
prism diopters.
319
N
"'a"
4:0
7:0
5:6
6:10
4:10
6:2
6:11
10:0
6
7
8
9
10
11
12
13
~
3:0
6:7
5
prism diopters; ET
0:4
6:11
4
PD
0:10
6:6
3
esotropia; RMR
~
3:11 3:11
0:5 0:10 1:3
1:5
1:3
0:7 0:11 1:8
1:1 2:0
1:1
1:2
1:2
0:6 0:7
0:5 0:8
0:7 0:7 2:0
0:7 0:8 1:8
0:6 1:9 4:11
0:4 2:1
0:4 0:4 0:6 2:2
At Injection
4:2
1:11
1:9
1:9
1:4
1:3
1:1
1:0
0:8
~
20/60 20/40
20/30 20/30
20/25
20/25
20/70 20/100
20/40
20/30
20/30 20/30
20/70 20/30
20/30 20/30
20/200 20/30
20/25 20/30
20/30 20/30
20/30 20/30
20/25 20/25
Visual Acuity
Current
o
ETcc 4 ET' cc 4
ITa~
ETa 20
ITa~IT~
DVD
ETalO-~
EX cc 0 EX' cc 0
ET cv 10 - 25, DVD ET' cc 10 - 14, DVD' (Apattern)
XT cc 4, DVD XT' cc 10, DVD'
ET cc 16 - 20 ET' cc 16 - 20
ET cc 8 - 16 ET' cc 20
ET cc 15, DVD ET' cc 15
ET cc 25 ET' cc 16
ET cc 12 ET' cc 14, DVD'
ET c 12 ET' cc 20, ET' bif 10
DVD DVD'
Alignment Distance and Near
Current
~
Binoe
Alt
Binoe
Binoe
Binoe
Alt
Binoe
Binoe
Binoe
Binoe
Binoe
Binoe
Binoe
Striated Glasses
alternating.
Ptosis myopic
prisms
Ptosis
Ptosis
Ptosis
A-pattern
prisms
Ptosis
prisms
Ptosis
prisms
Ptosis
nystagmus prisms
Latent
prisms
Ptosis
prisms
Ptosis
Myopic
Comments
dissociated vertical divergence; Binoe = binocular; Alt
0:3
1:6
0:6
1:2
0:3
0:1
0:7
0:7
0:1
0:1
0:1
0:7
0:8
0:3
0:3
Lag Time (yrs:mos)
0:7
0:7
Initial Adequate Alignment
Age (yrs:mos)
left medial rectus; DVD
RMR 1.25 LMR 1.25
RMR 1.25 LMR2.5 LMR 5.0
LMR 3.7
right medial rectus; LMR
ET 10
-9.00 -9.00 ~
ET 25
+0.50 +0.50
o
RMR2.5
+0.25
0:9 ET 25
RMR2.5 LMR5.0 LMR 10
ET 35
+2.00 +1.50
RMR2.5
RMR 2.5 LMR2.5
0:6
ET40
ET 35
RMR 1.25 LMR 2.5
LMR 2.5 RMR2.5
ET 20 ET60
RMR 1.5 LMR 3.75 RMR5.0
LMR 1.25 RMR3.75 RMR6.25
RMR 2.5 LMR5.0 LMR5.0
LMR2.5 LMR 2.5
RMR 1.25 LMR 2.5 RMR2.5 LMR5.0
Injection Dose (units)
ET60
ET 50
ET45
ET 30
ET70
Initial Deviation (PD)
LMR2.5 RMR2.5
+7.87
+0.37 +0.50
+3.00 +2.50
+3.25 +3.87
+3.00 +2.50
+1.50 +1.50
+1.75 +2.00
+1.50 +1.50
-1.00 -1.00
Initial Refraction (spherical equivalent)
+8.00
0:11
0:5
0:3
0:3
0:7
0:6
5:2
~
0:3
6:4
0:4
First Diagnosed by Ophthalmologist
At Examination
2
Case No.
Age (yrs:mos)
Table 2. Clinical Characteristics
None
+/-
+/-
None
None
None
-/-
-/-
3000
3000
+/-
+/-
None
3000
+/+ -/-
None
None
400
-/-
-/-
+/-
3000
3000
+/-
-/-
Stereo Acuity (sec. of arc)
Worth 4 Dot Macro/ Micro
+ +
+ +
+
+
+
+
+
+
+
+
+
;j
+
~
......
;:r'
C")
~ -l
~
-"'"
-l
(t>
0-'
~
z
E
......
(t>
~ ;j
~
~
0"
o
§"
g:
o
'0
+
+
+
+
+
+
Own Physician
This Examination
Evidence for Binocularity
I ng . Botulinum Alignment for Congenital Esotropia have shown that fusional amplitudes with a major amblyoscope were universally found in patients who could fuse Worth 4 dots, the use of the major amblyoscope was believed to be redundant and not necessary for the current study.14,15 Five patients who fused also had stereopsis. One patient had stereopsis but no fusion. All of these patients showed only gross stereoacuity. A motor deviation of 10 PO or less at near-fixation point and the ability to fuse Worth 4 dots and demonstrate stereopsis were found in only 3 of the 12 patients (cases 1,9, and 10) studied. Only those three patients, therefore, were able to show an "optimum" binocular result. There were, however, an additional two patients (cases 4 and 7), wearing base-out prisms up to a total of eight to neutralize residual motor deviation over 10 PO, who were able to show sensory fusion and stereopsis. The results in these latter two patients were not included as optimum because of the presumed dependence on prisms to show sensory evidence of binocularity. A comparison can be made between this investigator's opinion and with the opinions of the original ophthalmologists. Eleven of the 12 patients were thought by the patient's own ophthalmologist to have binocularity. However, using the motor and sensory tests described above, this investigator determined that only three patients had findings considered optimum for the treatment of congenital esotropia.
Discussion In his discussion of the results of botulinum treatment for childhood strabismus, Von Noorden l6 proposed that a scientific comparison of chemodenervation and surgical alignment could only be achieved in a prospective randomized study. As previously noted, however, the age of alignment does not necessarily coincide with the age of first surgery,13 a fact that precludes any meaningful prospective study. Furthermore, as shown in this study, the age of satisfactory alignment lagged behind the age of initial injection by an average of 5 months. Therefore, a retrospective study of cases adequately aligned by botulinum would probably still be the best available database from which to derive conclusions concerning the efficacy of the chemodenervation technique. The results of the current study demonstrate conclusively that binocular vision, despite being described as subnormal by von Noorden,17 is possible in some of the botulinum-aligned patients if this alignment is secured by 2 years of age for a minimum of 6 months. Prior studies have shown that sensory testing is a necessary component of an investigation of binocularity because a patient may have relatively straight eyes but no binocularity on sensory testing (e.g., case 8).13 The resultant motor alignment in the botulinumtreated group showed that approximately 25% (3 of 12) could achieve 10 PO or less of residual misalignment and demonstrate fusion and stereopsis. An additional four patients (cases 2,3,8, and 11) achieved a near alignment of 10 PO or less, but none of these same patients could dem-
on strate both fusion and stereopsis. In addition, two of these patients did not even show a binocular response to the most rudimentary test-Bagolini-striated glasses. The current relatively small group of intensely studied botulinum-aligned subjects can be contrasted to a larger, slightly older group (average age, 9.5 years) of surgically aligned subjects studied in an identical manner by this investigator. 13 Of the 90 patients aligned surgically, 80 (88%) achieved the alignment to within 10 PO of orthophoria within 1 week of surgical treatment. Therefore, the efficiency of surgical treatment was greater than that of the botulinum-treated group, which averaged 5 months after initial injection to achieve alignment. This occurrence of delayed alignment with botulinum was even more notable, in that the botulinum-treated group averaged less deviation (41 PO) when compared with the more typical quantity (57 PO) found in the surgically treated group. Undoubtedly, the multiple injections necessary to treat the patients with greater deviations led to further delay in achieving satisfactory alignment. Additionally, eyes of only three patients of the botulinum-treated group straightened to within 10 PO of orthophoria without compensatory prisms and had both fusion and gross stereopsis in contrast to 66 of the 90 surgically aligned subjects who were able to do so without prisms. 13 Although the size of the current study group is small, it should be pointed out that these patients were selected as the best cases by the other investigators, and they were intensively studied. Botulinum treatment appears to be less effective than surgical treatment for establishing binocularity in congenital esotropia. There is a statistically significant difference in the outcome of the same tests between the two groups (chi-square 11.302; P < 0.001; ds = 1).
Acknowledgment The author thanks Drs. Alan Scott and Elbert Magoon, without whose patient referrals this study could not have been completed,
References 1. Scott AB. Botulinum toxin injection into extraocular muscles as an alternative to strabismus surgery. Ophthalmology 1980;87: 1044-9. 2. Magoon E, Scott AB. Botulinum toxin chemodenervation in infants and children: an alternative to incisional strabismus surgery. J Pediatr 1987; 110:719-22. 3. Scott AB. Botulinum injection treatment of congenital esotropia, In: Lenk-Schafer M, ed. Orthoptic Horizons: Trans Sixth Int'l Orthoptic Congress. London: British Orthoptic Society, 1988;294-9. 4. Magoon EH. Chemodenervation of strabismic children. A 2- to 5-year follow-up study compared with shorter followup. Ophthalmology 1989;96:931-4. 5. Scott AB, Magoon EH, McNeer KW, Stager DR. Botulinum treatment of childhood strabismus. Ophthalmology 1990;97: 1434-8. 6. Helveston EM, Ellis FD, Schott J, et al. Surgical treatment of congenital esotropia. Am J Ophthalmol 1983;96:218-28. 7. Kushner BJ, Morton GV. A randomized comparison of surgical procedures for infantile esotropia. Am J Ophthalmol 1984;98:50-61.
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Volume 100, Number 3, March 1993
8. Mims JL III, TreffG, Kincaid M, et al. Quantitative surgical guidelines for bimedial recession for infantile esotropia. Binocular Vis 1985;1:7-22. 9. Bartley GB, Dyer JA, Ilstrup DM. Characteristics ofrecession-resection and bimedial recession for childhood esotropia. Arch Ophthalmol 1985; 103: 190-5. 10. Scott WE, Reese PD, Hirsh CR, Rabetich CA. Surgery for large-angle congenital esotropia. Two vs three and four horizontal muscles. Arch OphthalmoI1986;104:374-7. II. Biglan AW, Burnstine RA, Rogers GL, Saunders RA. Management of strabismus with botulinum A toxin. Ophthalmology 1989;96:935-43. 12. Hague S, Lee JP. Botulinum toxin: an alternative to squint surgery in childhood? In: Campos EC, ed. Strabismus and Ocular Motility Disorders: Proc Sixth Meeting of the Inri
322
13. 14. 15. 16.
17.
Strabismological Association. Houndmills: Macmillan, 1991 ;413-20. Ing MR. Early surgical alignment for congenital esotropia. Trans Am Ophthalmol Soc 1981 ;79:625-63. Ing M, Costenbader FD, Parks MM, Albert DG. Early surgery for congenital esotropia. Am J Ophthalmol 1966;61: 1419-27. Parks MM. The monofixation syndrome. Trans Am Ophthalmol Soc 1969;67:609-57. von Noorden G. Discussion, 180-1. Of: Scott AB, Magoon EH, McNeer K, Stager DR. Botulinum treatment of strabismus in children. Trans Am Ophthalmol Soc 1989;87: 174-84. von Noorden GK. A reassessment of infantile esotropia. XLIV Edward Jackson Memorial Lecture. Am J Ophthalmol 1988;105:1-10.