Strabismus surgery in congenital third nerve palsy.

BACKGROUND: Congenital third nerve palsy is a rare condition that usually presents with a large-angle incomitant strabismus and is often associated with ptosis and amblyopia. METHODS: We present the results of strabismus surgery in seven consecutive patients. RESULTS; All the palsies developed before the age of 6 months and the age at surgery ranged from 3 to 24 years. The operations performed included horizontal recti resection/recession (7), supra-placement of the insertions (6), superior oblique weakening (4) and traction sutures (4). The preoperative and postoperative horizontal deviations consisted of seven exotropias and one esotropia due to a combined sixth and partial third nerve palsy. The preoperative vertical deviation consisted of 7 hypotropias and one hypertropia; postoperatively, 5 remained hypotropic and 2 were hypertropic. All patients underwent ptosis surgery. CONCLUSION: Patients with congenital third nerve palsy often achieve reasonable cosmesis with strabismus and ptosis surgery.

Active management in patients with ocular manifestations of myasthenia gravis.

PURPOSE: Myasthenia gravis can cause variable strabismus with disabling diplopia and/or poor cosmesis. A retrospective study of a group of patients with myasthenia gravis or 'myasthenia gravis like' syndromes was made. METHODS: The study group consisted of patients who had undergone botulinum toxin treatment and/or surgery for disabling diplopia, poor cosmesis or both. Surgical treatment was by conventional techniques including recess/resect, posterior fixation, superior oblique tenotomy and adjustable sutures. RESULTS: There were 9 patients in the study group (8 female, 1 male). Age at surgery ranged from 21 to 59 years (mean 46 years). Six were symptom-free following treatment. Two, although symptomatically improved, had occasional diplopia. One patient failed treatment and required an occlusive contact lens. CONCLUSIONS: The ocular manifestations of myasthenia gravis or 'myasthenia gravis like' syndromes may respond to surgery and/or botulinum toxin injection. Active intervention should be considered when deviations become stable. To our knowledge this is the first report of the use of botulinum toxin in such patients.

Retinal haemorrhage and fatal stroke in an infant with fibromuscular dysplasia.

Non-accidental injury should be suspected and excluded in any infant found to have intracranial and retinal haemorrhage of unknown aetiology. This can be a sensitive issue for both medical staff and parents. We present a case in which the underlying cause of intracranial and retinal haemorrhage was fibromuscular dysplasia. It was a diagnosis made only at postmortem examination and it illustrates the diagnostic difficulty such cases may present.

Sclerosing canaliculitis after 5-fluorouracil breast cancer chemotherapy.

BACKGROUND: 5-Fluorouracil is a pyrimidine analogue that inhibits DNA synthesis and is commonly used in the treatment of carcinomas of the breast, gastrointestinal tract and genitourinary tract. Excessive tearing that resolves on cessation of treatment is commonly described as a side effect of the drug. Permanent stenosis of the punctum and canaliculus is extremely rare, with only 12 cases reported in the world literature. We present three cases of established lacrimal outflow obstruction in patients who were treated with CMF (cyclophosphamide, methotrexate, 5-fluorouracil), a widely used regimen for metastatic breast cancer. Patient 1 had right distal stenosis of her lower canaliculus and was syringed patent during dacryocystography with resolution of epiphora. Patient 2 had proximal blockage of all canaliculi and underwent bilateral canaliculodacryocystorhinostomy with silicone tubes that temporarily relieved symptoms until tube removal. The proximal canalicular blockage recurred due to underlying extensive fibrosis. Patient 3 had right proximal common canalicular stenosis and left distal canalicular blocks but declined surgery. CONCLUSION: With the rise in the incidence of breast carcinoma it is important that the attention of both ophthalmologists and oncologists should be drawn to the potential ocular toxicity of systemic 5-fluorouracil chemotherapy, which may lead to lacrimal canalicular fibrosis with permanent epiphora. The management of these patients is challenging as there is a continuous spectrum of canalicular involvement from focal to diffuse; therefore early referral is recommended. Moreover as no consensus has been reached as how best to manage this unique small group of patients, we review the literature and discuss the implications for treatment.

Fast eye movement initiation of ocular torsion in mesodiencephalic lesions.

Three patients with episodic ocular torsion and skew deviation due to mesodiencephalic lesions were studied by using binocular three-dimensional scleral search coils. The conjugate ocular torsion (upper pole of each eye rotating toward the side of the brainstem lesion) was initiated by a torsional fast eye movement. During prolonged episodes, torsional nystagmus was also present. Cessation of the ocular torsion and skew deviation occurred by slow eye movements with exponentially decreasing velocities in 2 patients, and by multiple fast torsional movements in 1 patient. In 1 patient, the abnormal eye movements were temporally linked to dystonic movements in the limbs on the side opposite the brainstem lesion. The occurrence of skew deviation with conjugate ocular torsion in brainstem lesions has been attributed to functional asymmetry in vestibular pathways responsible for the slow-phase compensatory eye movement response to roll. In comparison, the findings in our patients show that in mesodiencephalic lesions conjugate ocular torsion with skew deviation may be generated by torsional fast eye movements, indicating activation of the burst cells of the rostral interstitial nucleus of the medial longitudinal fasciculus.

Dissociated effects of botulinum toxin chemodenervation on ocular deviation and saccade dynamics in chronic lateral rectus palsy.

AIM: Changes in saccade velocity/amplitude characteristics (main sequence) and attenuation of distance esotropia in response to botulinum toxin (BTX-A) chemodenervation of the antagonist medial rectus were studied in a group of nine patients with chronic lateral rectus palsy. METHODS: Serial measurements of ocular deviation and infrared oculograms of saccadic eye movements to targets at 5 degrees-20 degrees of lateral gaze were made before injection and at 2, 4, 8, 16, and 20 weeks after injection. RESULTS: At 2 weeks after injection, the ocular deviation changed by a mean of 34.5 prism dioptres and the 5 degrees and 10 degrees adduction saccades were significantly slowed (p < 0.02 Wilcoxon signed rank test). By the second examination, however, the adducting saccade peak velocity had returned to normal while the mean ocular deviation remained significantly changed (p = 0.01 Wilcoxon matched pairs). By 20 weeks the mean ocular deviation was not significantly different from that before injection (p = 0.14 matched pairs). CONCLUSIONS: The ocular realignment caused by BTX-A may persist after saccadic function has been restored. This may be because toxin may have a more profound and long lasting effect on the orbital singly innervated fibres which are active tonically at rest to hold gaze whereas there is relative sparing of the additional motor units recruited during fast eye movements.

Ocular ultrasound in Alagille syndrome: a new sign.

BACKGROUND: Alagille syndrome (AS) is one of six forms of familial intrahepatic cholestasis, all of which present with neonatal jaundice and paucity of intrahepatic bile ducts. Differentiation of these individual syndromes is crucial as their treatments and prognoses vary. It is the ophthalmic features, posterior embryotoxon on particular, that distinguish AS. METHODS: The authors performed full ocular examination, including A- and B-scan ultrasound, refraction, and, where possible, fluorescein angiography in 20 unrelated children with AS and 8 with non-AS-related cholestasis. RESULTS: There was ultrasound evidence of optic disc drusen in at least one eye in 95% and bilateral disc drusen in 80% of patients with AS but in none of the patients who were non-AS at the time of examination. Independent review of hard-copy scans suggested drusen in at least one eye in 90% of the cases and bilateral drusen in 50%, although this latter figure rose to 65% on review of the angiograms. This is markedly higher than the incidence in the normal population (0.3%-2%). Axial lengths were shorter than expected for the older age group (older than 10 years of age), but this was not associated with gross ametropia. CONCLUSION: This strong association of AS and optic disc drusen has not been reported previously and represents not only the first significant association between a systemic condition and disc drusen but also a possibly useful tool in the diagnosis of AS, especially in young children.

Retinopathy in haemoglobin C trait.

Retinopathy associated with sickle-C and sickle cell disease is well described. Sickle trait and haemoglobin C trait are generally considered benign conditions, with infrequent systemic manifestations. Rare cases of retinopathy in sickle trait, in the presence of contributory factors, exist and we recently reported three such patients. The occurrence of retinopathy in haemoglobin C trait is even less well documented. Haemoglobin C does not cause red blood cell sickling but is known to decrease erythrocyte plasticity and increase blood viscosity. We report three cases in which haemoglobin C trait was associated with significant peripheral vascular occlusion and seafan formation (confirmed by fluorescein angiography) similar to that seen in sickle retinopathy. Two patients had coexistent systemic disease (hypertension and diabetes mellitus). Vitreous haemorrhage was the presenting feature in two patients. It is evident that haemoglobin C trait may be associated with sight-threatening complications.

Sickle retinopathy in patients with sickle trait.

Sickle trait is traditionally considered a benign condition by ophthalmologists. Three cases of sickle retinopathy in subjects with sickle trait are reported. In all cases the onset of retinopathy was related to other contributing factors: in one case a traumatic hyphaema and raised intraocular pressure, in two others diabetes mellitus. Patients with sickle trait are at risk of retinopathy if coincident ocular or systemic disease is present.

The effect of surgery on the AC/A ratio.

The accommodative convergence/accommodation (AC/A) ratio is used clinically as a diagnostic tool in the assessment of convergence excess and near esotropia and the differentiation of true and simulated divergence excess. An abnormally high AC/A ratio has been implicated in the aetiology of some forms of strabismus but the evidence for alteration in the ratio following surgery is inconclusive. In a prospective study of 38 patients the effect of routine squint surgery was investigated in concomitant strabismus. The AC/A ratio was found to decrease significantly after surgery in both esotropes and exotropes. Furthermore a trend was demonstrated which suggested an increased risk of overcorrection in esotropes with a high (> or = 7:1) pre-operative AC/A ratio.

Churg-Strauss vasculitis presenting with severe visual loss due to bilateral sequential optic neuropathy.

A 44-year-old man with severe visual loss due to an acute bilateral sequential optic neuropathy is described, where the associated pulmonary disease and peripheral eosinophilia led to a diagnosis of Churg-Strauss syndrome (allergic angiitis). The mechanism of the optic neuropathy was most probably acute ischaemia of the anterior optic nerve due to direct involvement of the short posterior ciliary arteries by inflammatory disease of the vessel wall.

Macular ischaemia in posterior uveitis.

The commonest cause of visual morbidity in patients with posterior uveitis is cystoid macular oedema, which usually responds to immunosuppressive treatment. However, a small group of patients do not have a satisfactory visual outcome despite apparently adequate therapy. In a retrospective study of 345 angiograms of 135 patients with active non-occlusive retinal vasculitis 12 patients were identified by independent masked review as showing macular ischaemia on their fluorescein angiograms. Four patients had Behçet's disease, 4 sarcoidosis, and 4 idiopathic retinal vasculitis. Follow-up of these patients for an average of 36 months (range 6-120 months) showed that visual acuity failed to improve in 4 patients and dropped by an average of three lines Snellen in the other 8. We suggest that a poor visual outcome in some patients with posterior uveitis may be predicted by the presence of macular ischaemia on fluorescein angiography and that immunosuppressive therapy should be prescribed with caution in these patients.

Laboratory antarctica: research contributions to global problems.

Research in Antarctica is becoming increasingly important in the large interdisciplinary studies of connections within the earth's geosphere-biosphere system. Four examples of broad research areas are discussed. Upper atmosphere research explores the sun-earth interactions, which are most intense in the polar regions. The mass balance and dynamics of the large Antarctic ice sheet, and its paleoclimatic records recovered from deep ice cores, are important indicators of past and present global changes. Antarctica and sediment cores from the Southern Ocean contain the history of inception and growth of the ice masses and their subsequent fluctuations, and the long-term history of paleoclimate. The remarkable adaptations of Antarctic biota to extreme cold and drought may allow, through biotic monitoring, the detection of changes in the ocean and climate of Antarctica.

Apparent respiration rate of the human corneal epithelium with tetracaine HCl and benoxinate HCl.

Local anesthetics may have a cytotoxic effect which causes a depression in the apparent epithelial oxygen uptake rate (AEOR) of the cornea. We measured the AEOR of human corneas in vivo before and after applying 1% tetracaine (amethocaine) HCl and 0.4% benoxinate HCl. These drugs had no effect on AEOR. In human corneas that had been subjected to a period of hypoxia, AEOR was slightly higher after administration of benoxinate, a result in the opposite direction to that expected on the grounds of toxicity. The increase was not statistically significant. We conclude that clinical doses of tetracaine HCl and benoxinate HCl normally have a minimal cytotoxic effect, and that this is similarly true when benoxinate is applied to the cornea after contact lens wear.

Clearing of psoriasis after cardiac surgery requiring cardiopulmonary bypass oxygenation: a corollary to clearance after dialysis?

A 54-year-old man had severe psoriasis with associated arthritis for 10 years. Attempts at therapy with tars, topical steroids and a short course of ultraviolet light were unsuccessful. His psoriasis cleared 6 weeks after cardiac surgery requiring cadiopulmonary bypass oxygenation.

Treatment of psoriasis with dialysis.

Five patients with psoriasis were treated with haemodialysis. Dialysis therapy was initiated for subsequent development of uraemia in three cases. All of these had successful renal transplants without recurrence of psoriasis while being maintained on post-transplant anti-rejection regimens. Two other cases were haemodialysed, not for uraemia but primarily for psoriasis. One case had moderate improvement of psoriasis after twice-weekly dialysis for two months while the second had no objective improvement up to one month after a single haemodialysis treatment.