Ethambutol and optic neuropathy.

PURPOSE: To demonstrate the association between ethambutol and optic neuropathy. METHOD: Thirteen patients who developed optic neuropathy after being treated with ethambutol for tuberculosis of the lung or lymph node at Siriraj Hospital between 1997 and 2001 were retrospectively reviewed. The clinical characteristics and initial and final visual acuity were analyzed to determine visual outcome. RESULTS: All patients had optic neuropathy between 1 to 6 months (mean = 2.9 months) after starting ethambutol therapy at a dosage ranging from 13 to 20 mg/kg/day (mean = 17 mg/kg/day). Seven (54%) of the 13 patients experienced visual recovery after stopping the drug. Of 6 patients with irreversible visual impairment, 4 patients had diabetes mellitus, glaucoma and a history of heavy smoking. CONCLUSION: Early recognition of optic neuropathy should be considered in patients with ethambutol therapy. A low dose and prompt discontinuation of the drug is recommended particularly in individuals with diabetes mellitus, glaucoma or who are heavy smokers.

Botulinum toxin treatment of the sixth nerve palsy: an experience of 5-year duration in Thailand.

Forty-five patients (48 eyes) with sixth nerve palsy were treated with botulinum toxin injection to antagonist medial rectus muscle at Siriraj Hospital from October 1995 to September 2000. The common causes of palsy were ischemia, trauma and inflammation. Thirty-eight patients (group I) had an interval to treatment of less than 24 weeks (average, 8.7 weeks) and seven patients (group II), longer than 24 weeks. The mean pre-injection esodeviation and extent of abduction in group I were 28.1 prism diopters (PD) and 28.4 per cent, and in group II were 38 PD and 8.1 per cent respectively. After a mean follow-up of 12.2 months, twenty-seven (71.1%) patients in group I recovered completely after the first injection and three (7.9%), after the second injection with a mean interval to recovery of 8.1 weeks. One (14.3%) of 7 patients of group II obtained complete recovery without fusion. Twenty-six (83.9%) of 31 patients with complete resolution achieved binocular function. We conclude that botulinum toxin treatment is a safe and effective alternative to traditional surgery of acute onset sixth nerve palsy.

Botulinum toxin treatment of sixth cranial nerve palsy.

Twelve patients with sixth cranial nerve palsy were treated with botulinum toxin injections to the antagonist medial rectus muscle at Siriraj Hospital between October 1995 and June 1996, The angle of esotropia, the extent of abduction and stereopsis were measured in all patients before and after the injections. After the treatment, seven patients (58.3 per cent) who exhibited a short duration of palsy, small angle of esotropia and incomplete paresis of the lateral rectus muscle recovered to achieve orthotropia and re-established fusion in the primary position. Of those seven patients, five demonstrated complete recovery of ocular motility. Botulinum toxin treatment can not only be a safe and effective alternative to conventional surgery but can also restore single binocular vision in primary gaze.

Retinal detachment with macular hole.

Retinal detachment with macular hole was treated by different methods. Intravitreal SF6 injection was helpful to seal the macular hole and reattach the retina. In cases of retinal detachment with macular hole and peripheral retinal tear, the retinal reattachment could be achieved by scleral buckling procedure. When vitreous traction adjacent to the macular hole or proliferative vitreoretinopathy was present, vitrectomy combined with internal temponade by SF6 gas injection was indicated. Failure of the operation was caused by inadequate removal of the vitreous traction and post-operative vitreoretinopathy. In a successful operation, visual acuity of 6/60 or better was found in eight of thirty-one patients. (25.8%)

Sport eye injury: A case report.

A case of sport injury of right eye due to baseball is reported. The ocular findings include poor vision, fracture medial wall and floor of orbit, traumatic maculopathy, angle recession are diagnosed. The mechanism of injury and the prognosis are discussed. This is the first case report of sport eye injury due to baseball at the Department of Ophthalmology, Faculty of Medicine Siriraj Hospital.