Ruth Huna-Baron

Analysis of prothrombotic and vascular risk factors in patients with nonarteritic anterior ischemic optic neuropathy

OBJECTIVE To determine whether genetic or acquired thrombophilias and other risk factors are associated with nonarteritic anterior ischemic optic neuropathy (NAION). DESIGN Retrospective case-control study. PARTICIPANTS Sixty-one patients with NAION diagnosed between 1984 and 1997. Ninety consecutive patients who visited the Eye Institute made up the control group. INTERVENTION Protein C, protein S, antithrombin III, lupus anticoagulant, and three recently described prothrombotic polymorphisms (i.e., factor V G1691A, factor II G20210A, and methylenetetrahydrofolate reductase [MTHFR] C677T) were analyzed. In addition, risk factors for arteriosclerotic vascular disease were assessed. MAIN OUTCOME MEASURES Parameters of thrombophilia. RESULTS None of the thrombophilic markers (genetic and acquired) constituted a significant risk factor for NAION. Ischemic heart disease, hypercholesterolemia, and diabetes mellitus were discerned as risk factors for NAION with odds ratios of 2.9 (95% confidence interval [CI], 1.3-6.4), 2.6 (95% CI, 1.2-5.5), and 2.3 (95% CI, 1.1-4.8), respectively. Multiple logistic regression analysis indicated that ischemic heart disease and hypercholesterolemia exerted an additive risk for NAION with a combined odds ratio of 4.5 (95% CI, 1.4-14.5). However, none of these risk factors statistically predicted second eye involvement. CONCLUSION NAION was not found to be associated with thrombophilic risk factors, yet it was related to ischemic heart disease, hypercholesterolemia, and diabetes mellitus.

Idiopathic intracranial hypertension in pregnancy

Objective Since idiopathic intracranial hypertension (IIH) is most prevalent in obese women of childbearing age, concerns arise regarding the impact of pregnancy on the disorder and the potential teratogenicity of some therapeutic agents. We evaluated the course, management of pregnant IIH patients and the visual and pregnancy outcomes. Methods Case series of pregnant women diagnosed with IIH. IIH symptoms, neuro-ophthalmological findings, IIH management, visual and pregnancy outcomes were documented. Results Among 240 women with IIH, 12 had 16 pregnancies. Ten had headaches, five had transient visual obscurations, and three had diplopia. Visual acuity was severely decreased in one and mildly reduced in three women. Six had marked and six had mild bilateral papilledema. Visual field loss occurred in four women. Visual symptoms and loss improved for the duration of the pregnancy after diagnostic lumbar puncture and salt restricted diet in three. Two additional women needed continuous spinal drainage for two days. One woman was treated with acetazolamide and medical abortion. The one woman with severe vision loss had fenestration of one optic nerve sheath and a lumboperitoneal shunt as well as corticosteroids and was the only case with permanent field loss. After intervention, visual acuity improved in all cases with reduced vision. There were 10 full-term normal deliveries, three missed abortions, one therapeutic abortion and two intrauterine fetal deaths. Conclusions IIH appears to present during the first two trimesters of pregnancy with typical symptoms and findings. Visual outcome is similar as for non-pregnant women. Treatment should be oriented towards dietary control, without ketosis. Repeated spinal fluid drainage, if needed, can be helpful.

Thrombophilia as a cause for central and branch retinal artery occlusion in patients without an apparent embolic source

Purpose To assess the prevalence of vascular risk factors and thrombophilias in central and branch retinal artery occlusion in patients in whom an embolic source is not apparent.Methods The study group consisted of 21 consecutive patients with retinal artery occlusion (RAO) in whom Doppler ultrasonography of the carotid arteries and transthoracic or transoesophageal echocardiography were normal. Laboratory methods included polymerase chain reaction for detection of factor V G1691A, factor II G20210A and methylentetrahydrofolate reductase C677T mutations, assays of plasma levels of protein C, free protein S, antithrombin, fibrinogen and homocysteine; and tests for the presence of lupus anticoagulant and anticardiolipin antibodies. Controls for the laboratory tests were 243 healthy subjects.Results Nine of the 21 (43%) patients had at least one thrombophilic marker: 4 were homozygous for MTHFR C677T, 1 was heterozygous for factor V G1691A, 1 had a high titre of IgM anticardiolipin, 2 were heterozygous for factor V G1691A and homozygous for MTHFR C677T, and 1 had lupus anticoagulant, a high titre of IgM anticardiolipin, homozygosity for MTHFR C677T and hyperhomocysteinaemia. An interaction between vascular risk factors and thrombophilias seemed important since out of 14 patients with hypertension, diabetes and/or hypercholesterolaemia 7 (50%) had a thrombophilia. Homozygous MTHFR C677T was a significant risk factor with odds ratio of 3.18 (95% CI 1.20-8.47). The prevalence of factor V G1691A was also higher in the RAO patients versus controls with an odds ratio of 2.36 (95% CI 0.63-8.88), but this value did not reach significance, probably due to the small sample size.Conclusion A search for thrombophilia in RAO is advisable in patients without evident source of emboli even when vascular risk factors are identified.

Orbital arteriovenous malformation mimicking cavernous sinus dural arteriovenous malformation

AIMS Orbital arteriovenous malformations (OAVM) are rare, mostly described with high flow characteristics. Two cases are reported with an OAVM of distinct haemodynamic abnormality. The clinical, angiographic features, and the management considerations are discussed. METHODS Case review of two patients with dural AVM (DAVM) who presented to referral neuro-ophthalmology and endovascular services because of clinical symptoms and signs consistent with a cavernous sinus dural AVM. RESULTS In each patient, superselective angiography revealed a small slow flow intraorbital shunt supplied by the ophthalmic artery. The transarterial and transvenous endovascular approaches to treat the malformation were partially successful. Although, the abnormal flow was reduced, complete closure of the DAVM could not be accomplished without significant risk of iatrogenic injury. Neither patients vision improved after intervention. CONCLUSION A DAVM in the orbit can cause similar clinical symptoms and signs to those associated with a cavernous sinus DAVM. Even with high resolution magnetic resonance imaging, only superselective angiography can identify this small intraorbital slow flow shunt. The location in the orbital apex and the small size precludes a surgical option for treatment. The transarterial and transvenous embolisation options are limited.

Infantile Cerebral Aneurysms with Visual Pathway Compression

Intracranial aneurysms are rare in infancy. The commonest presentation is intracranial hemorrhage, but signs of mass effect are more frequent than in adults. We report 2 infants with cerebral aneurysms, one presenting with macrocephaly and another with strabismus. Both had visual loss and optic disc pallor; MRI revealed a suprasellar mass and anterior visual pathway compression. In both cases, the preoperative diagnosis was craniopharyngioma. It is essential to recognize that, although exceedingly uncommon, cerebral aneurysms do occur in infants and have features that differ from those in adults.

The role of angiotensin converting enzyme and angiotensin ii type 1 receptor gene polymorphisms in patients with nonarteritic anterior ischemic optic neuropathy

OBJECTIVE To determine the role of angiotensin converting enzyme (ACE) and angiotensin II type 1 receptor (AT1R) polymorphisms in the pathogenesis of nonartertic anterior ischemic optic neuropathy (NAION). DESIGN Retrospective, case-control study. PARTICIPANTS Seventy-four patients with NAION diagnosed from 1984 through 1999. Seventy-one patients who visited the Eye Institute comprised the control group. TESTING INTERVENTION: DNA was extracted from whole blood obtained from all patients and control participants. Polymerase chain reaction (PCR) was used for analysis of ACE and AT1R polymorphisms. RESULTS The frequency of the polymorphism for ACE among the NAION patients (39.2% deletion allele [DD], 54.0% deletion/insertion [D/I] locus, 6.8% insertion allele [II]) was similar to that of the control group (50.7% DD, 39.4% D/I, 9.9% II), with P = 0.21. The frequency of the polymorphism of AT1R in the NAION patients was 5.4% CC, 44.6% CA, 50% AA, and in the control group it was 4.2% CC, 33.8% CA, 62.0% AA, with P = 0.35. Participants less than 55 years of age and those more than 55 had quite similar distributions. CONCLUSIONS Angiotensin converting enzyme and AT1R polymorphisms have no part in the mechanism of NAION. Thus drugs such as ACE inhibitors or AT1R antagonists are not specifically indicated for treatment of these patients.