[Qualitative analysis on the denervating action of botulinum toxin A in gel].

AIM: To ascertain the bioactivity and to analyse quantificationally the denervating action of botulinum toxin A (BTXA) in gel. METHODS: 36 Sprague-Dawley rats were randomized into four groups. In group A - D, the gastrocnemius muscle of one leg was randomly selected to receive injection of BTXA solution 5U in 0.1 ml, BTXA gel 12.5U in 0.1 ml, BTXA gel 5U in 0.1 ml and BTXA gel 2U in 0.1 ml respectively, while the gastrocnemius muscle of other leg was injected with 0.1 ml of saline solution in group A and 0.1 ml of gel in group B to group D as control. Compound muscle action potential (CMAP) of both gastrocnemius muscles were measured and the amplitudes were recorded before injections, and 5 days, 2 weeks, 3 weeks, 1 month, 2 months and 3 months after the injections respectively. RESULTS: The reduction of CMAP amplitude was significantly different at various time (P < 0.01), and CMAP amplitude decreased significantly after the treatment of BTXA (P < 0.01). The reduction of CMAP amplitude was significantly dif ferent in group A to I) (P < 0.01), and more reduction was found in group A and B (P < 0.01), and the reduction was higher in group C than in group D (P < 0.05). However, there were no significant differences in the reduction of CMAP amplitude between group A and group B. CONCLUSION: Bioactivity of BTXA in gel was showed and the denervating action of BTXA in gel was demonstrated in a dosage and time dependent manner.

[The clinical features and surgical treatment of masked bilateral superior oblique palsy].

OBJECTIVE: To investigate the clinical features, diagnosis and the management of masked bilateral superior oblique palsy (MBSOP). METHODS: Retrospectively analyzed the records of all 7 patients that met the clinical criteria for MBSOP in Zhongshan Ophthalmic Center between 1999 and 2003. The head tilt, vertical deviation in primary position and the action of obliquus pre- and postoperatively were collected in detail. RESULTS: All 7 patients were diagnosed as unilateral SOP in the first time. The average hypertropia in primary position preoperatively was 19.7(Delta) (range 6(Delta) to 30(Delta)). All patients had a head tilt, obvious unilateral inferior oblique overaction (+2 to +4) and mild superior oblique underaction (-1 to -2), and normal action in contralateral superior and inferior obliquus. Initial surgery consisted of ipsilateral inferior oblique weakening with (5 patients) or without (2 patients) ipsilateral superior rectus recession. The average hypertropia in primary position was 12.0(Delta) (range 0(Delta) to 20(Delta)) after the first operation. In 1 week to 4 years, all of the previously masked eye presented the inferior oblique overaction (+2 to +3) and superior oblique underaction (0 to -1). All patients underwent a second surgery in 4 months to 4 years after the initial surgery. The average hypertropia in primary position was 2.3(Delta) (range 0(Delta) to 7(Delta)) after the second operation. Postoperative alignment was excellent in all patients. CONCLUSIONS: Masked bilateral superior oblique palsy is quite difficult to detect before surgical correction of the initial manifest palsy. The possibility of an occult contralateral palsy should be considered in all undergoing surgery for unilateral SOP. The superior rectus recession and the inferior oblique weakening procedure should be performed at different stages. When the masked palsy becomes evident, a successful surgical outcome can usually be expected.

[The effect of weakening the overaction superior oblique muscles on the status of ocular torsion].

OBJECTIVE: To investigate the effect of weakening the superior oblique muscles on the status of ocular torsion. METHODS: Twenty-nine patients (58 eyes) underwent tenotomy or partial ectomy of bilateral superior oblique muscles for treatment of superior oblique overacting. Objective cyclodeviations were assessed by fundus photograph before and 7 days after the surgery. The photographs were transferred to a computer and then the fovea-disc angle was measured by a software for drawing pictures. Subjective cyclodeviations and binocular vision function were assessed by synoptophore. RESULTS: Fundus photography before surgery revealed that the intorsion was 10.48 degrees +/- 6.01 degrees for the right eye and was 9.37 degrees +/- 5.88 degrees for the left eye. The reduction of the cyclodeviations by weakening the superior oblique muscle for the right and left eye was 9.11 degrees +/- 7.09 degrees and 7.94 degrees +/- 4.76 degrees respectively. The comparisons of objective ocular torsion for both eyes showed high significant differences (P < 0.01) pre- and post-operatively. There were no significant differences (P > 0.05) between the effects of tenotomy or partial ectomy of bilateral superior oblique muscles. All patients showed no cyclotropia and normal binocular vision function was obtained with synoptophore before and after surgery. CONCLUSIONS: Weakening the overaction superior oblique could correct ocular incyclodeviation. Both tenotomy and partial ectomy of bilateral superior oblique muscles can treat ocular incyclodeviation effectively. The changes of subjective and objective cyclodeviations are inconsistent with each other.

[Clinical features of V patterns strabismus and its long-term effect of surgical treatment].

OBJECTIVE: To investigate the features and treatment of V patterns strabismus. METHODS: Pre- and post-operative deviation and oblique muscle action as well as binocular visual function were evaluated in sixty-three V pattern patients. The difference between upgaze and downgaze of deviation were recorded before and after operation. RESULTS: Sixty-two patients (98.4%) with binocular or unilateral inferior oblique overaction + 2 to + 3 were treated with inferior oblique weakening procedure and horizontal rectus recession-resection procedure. 1 patient with binocular inferior oblique overaction + 1 treated with horizontal recti recession-resection procedure. The difference between upgaze and downgaze is 25.6 prism diopters (PD) preoperatively and 4.5 PD postoperatively. The primary-position exotropia preoperatively of 48 V pattern exotropia is 37.2 PD, after surgery, the average deviation is 3.4 PD of esotropia [38 cases (79.2%) with deviation within +/- 10 PD]. 15 cases of V pattern esotropia had deviation 50.6 PD preoperatively, after surgery, the average deviation is 2.4 PD of esotropia [11 cases (73.3%) with deviation within 10 PD]. 21 patients (33.3%) obtained stereo visual function after surgery. CONCLUSION: V patterns always had inferior oblique over action and could be treated with the inferior oblique weakening procedure. The primary-position deviation should be treated by traditional horizontal rectus recession-resection procedure. The stereoscopic function had a good prognosis with surgery.

[The effect of interleukin-1alpha on intraocular pressure in rabbit eyes and its focal side effects].

OBJECTIVE: To investigate the efficiency of interleukin-1alpha on intraocular pressure reduction and its safety. METHODS: 35 New Zealand female rabbits were randomized into seven groups. In group-A, one eye was randomly selected to receive sub-conjunctival injection of 15 ng IL-1alpha, and in group B-D, one eye was injected intracamerally with IL-1alpha 1.5 ng, 15 ng and 40 ng respectively, and the other eye was injected intracamerally with equivalent volume of 0.1% PBS as control. In group-E, one eye was treated with 0.5% timolol eye drops and the other eye was given artificial tear. Groups F and G were treated as group D, and specifically in group-G, both eyes were given IL-1alpha. In group-A to D, the examination of tonometry, slit-lamp biomicroscopy and direct ophthalmoscope were taken before treatment and 24 hours after the treatment and were repeated everyday for 4 days. In group-E, tonometry was applied before treatment and 7 days after treatment. In group-F, aqueous humor of two eyes was aspirated for smear examination 24 and 48 hours after treatment, and corneal endothelium microscope and flash-ERG were done in group-G before and 30 to 40 hours after treatment, and then the eyes were enucleated for histology analysis. RESULTS: IOP of the eyes received IL-1alpha was decreased significantly compared with that of contralateral control eyes in group A to D (P < 0.05). Peaking time of IOP reduction was 72 - 96 hours after treatment, and IOP reduction was continued for over 96 hours. The IOP reduction efficiency in group C and D was more significant than those of group E (P < 0.05). No significant abnormal was found with the examinations of slit-lamp biomicroscopy, ophthalmoscope, corneal endothelium microscopy, flash-ERG, smear and histological observation, except for mild focal conjunctival congestion. CONCLUSION: Intraocular reduction were demonstrated with IL-1alpha treatment, charactered by its strong hypotensive effect, long duration and safety.

[The effect of weakening inferior oblique muscles on the status of ocular torsion].

OBJECTIVE: To understand the clinical significance of subjective and objective examination of cyclodeviations and investigate the effect of weakening inferior oblique muscles on the status of ocular torsion. METHODS: Twenty patients (40 eyes) with overacting inferior oblique muscles underwent bilateral myotomy or partial myectomy of inferior oblique muscles. Subjective cyclodeviations were measured before surgery as well as one week, two months after surgery by double maddox rod test (DMRT). Objective cyclodeviations were assessed by fundus photography before and 7 days after surgery in 15 cases. The photograph was transferred to a computer, and the fovea-disc angle was measured by means of drawing picture software. RESULTS: Nine patients with primary overaction of inferior oblique muscles were negative with DMRT before surgery, and only one case revealed incyclotropia 5.0 degrees tested two months after surgery. Four out of 11 patients with secondary overaction of inferior oblique muscles showed excyclotropia 2.5 degrees - 5.0 degrees with DMRT before surgery, and all patients indicated no subjective cyclotropia with DMRT two months after surgery. Fundus photography determination of the right eye revealed extorsion 16.83 degrees +/- 6.39 degrees, the left eye 14.92 degrees +/- 4.51 degrees before surgery. The reduction of the cyclodeviations by weakening inferior oblique muscle for the right and left eye was 13.07 degrees +/- 3.38 degrees and 10.54 degrees +/- 3.75 degrees respectively. The comparison of objective ocular torsion for both eyes showed high significant differences (P < 0.01) pre- and post-operatively. CONCLUSIONS: The results of subjective and objective examination of cyclodeviations in patients with primary or secondary overacting inferior oblique muscle early after birth were not consistent. Weakening inferior oblique muscle could correct excyclodeviation. There exist complicated compensatory mechanisms for subjective change of ocular torsion after surgery. The changes of subjective and objective cyclodeviations are still inconsistent.