Clinical features and treatment of near-work-related acquired esotropia.

AIM: To investigate the characteristics of near-work-related esotropia and the clinical efficacy of botulinum toxin type A (BTXA) injection therapy on it. METHODS: A total of 107 patients aged 15-57y with near-work-related esotropia were taken as the BTXA-treated group, and 30 other peers without near-work-related esotropia were included in the control group. All participants were refractive corrected to analyse the clinical characteristics of near-work-related esotropia. All subjects were examined including Worth4 spot examination, stereoscopic vision, strabismus angle, accommodative convergence to accommodation ratio (AC/A), far and near positive and negative convergence, positive and negative fusion range, positive and negative relative accommodation. Clinical efficacy was evaluated at a period of 10mo follow-up. RESULTS: The distant and near stereopsis were found in 84.9% and 77.5% of patients in the BTXA-treated group, respectively. In the control group, all patients had distant and near stereopsis. The incidence of taking off one's glasses to see close objects was significantly higher in the BTXA-treated group than in the control group (P<0.05). The BTXA-treated group showed a smaller range of in-fusion (9.84±5.72)° than the control group (22.04±8.71)° (P<0.05). The near esotropia angle of the BTXA-treated group (17.08±11.98)Δ was significantly smaller than the distant esotropia angle (19.07±11.68)Δ (P<0.05). Ten months after injection, the diplopia and esotropia of most patients underwent improvements after treatment (P<0.05). CONCLUSION: This study reveals that the accommodation function and the habit of near work without wearing spectacles are associated with near-work-related esotropia, while the length of time for near work and the onset time are independent of near-work-related esotropia. Additionally, BTXA injection therapy plays a vital role in relieving diplopia and restoring eye position.

[The application of botulinum toxin A in the treatment of restrictive strabismus in thyroid associated ophthalmopathy].

OBJECTIVE: To observe the clinical effects of botulinum toxin A in the treatment of restrictive strabismus in thyroid associated ophthalmopathy (TAO). METHODS: Clinical data in 33 patients with restrictive strabismus in TAO treated with botulinum toxin A were analyzed retrospectively. Botulinum toxin A was injected into extraocular muscles guided by electromyography. Clinical data included the eye position, the eye movement and diplopia. RESULTS: There were 25 cases of vertical strabismus, 3 horizontal strabismus and 5 vertical combining horizontal strabismus in this group. The average degree of horizontal deviation was 35. 00+/-20. 53 (20 - 80 , M = 27. 59 ) , the average degree of vertical deviation was 29. 33+/-17. 27 ( 10 - 100 , M = 27. 5 ) . The average follow-up time was ( 17. 04+/-12. 77) months (5. 00+/-67. 73 months). Sixty one extraocular muscles were injected, including 31 inferior rectus, 16 medial rectus, 10 superior rectus and 4 lateral rectus. Each rectus was injected 6. 48+/-2. 12 times (4 -11times, M = 6). The interval between injections averaged (2.96+/-0. 70) months (0. 50 - 26. 00 months). The deviation degrees was decreased after injections, 15 cases were cured and did not require further surgery, 12 cases were improved and 6 cases showed poor response. The dosage for each injection averaged (8. 16+/-1. 43) U. CONCLUSIONS: Botulinum toxin A injection has a good effect in the treatment of restrictive strabismus in TAO. Better results were obtained when treated earlier. Compare with paralytic strabismus and comitant strabismus, the dosage of botulinum toxin A in each injection in TAO is higher, the mean changes of degree of deviation is slighter, the interval between injections and the duration of effect is shorter. Injection dosage should increase after repeated injections. Intolerable diplopia could be eliminated in some patients, therefore, a muscle surgery could be avoided.