Smoking as an aetiological factor in a pedigree with Leber's hereditary optic neuropathy.

BACKGROUND/AIMS: Leber's hereditary optic neuropathy (LHON) is a mitochondrial DNA mediated disease which causes severe visual deficits. Although expressivity of the disease is 100%, penetrance is variable, and environmental factors may influence risk of becoming symptomatic. The causative relation between cigarette smoking and disease penetrance was examined. METHODS: The incidence of smoking in 65 age matched family members of one LHON pedigree was retrospectively obtained. Smoking in groups which expressed disease was compared with those which did not. Male subgroups were analysed separately in addition to combined sex groups. RESULTS: The association between smoking and disease penetrance was significant in all subgroups (p values from p=0.0009 to p=0.0001, 95% confidence intervals). Disease penetrance was higher in males than females. The association was weaker in the male group than combined sex groups (p values from p=0.0146 to p=0.0008, 95% confidence intervals), probably because of elimination of female asymptomatic non-smokers in the comparison groups. The association was strengthened in older age groups and in groups which smoked more heavily. CONCLUSIONS: Smoking is significantly associated with disease penetrance in this LHON pedigree. Degree of smoking and number of years smoked correlate with increased risk of developing symptoms.

Porous polyethylene channel implants: a modified porous polyethylene sheet implant designed for repairs of large and complex orbital wall fractures.

PURPOSE: To evaluate the effectiveness of a modified porous polyethylene implant in orbital fracture repair. A porous polyethylene channel implant (PPCI) has internal channels that accept mini- or microplates from conventional plating systems, facilitating fixation to bone in the reconstruction of large, complex orbital fractures. METHODS: The authors used 29 PPCIs to repair 25 orbits. Seventeen cases involved repair of an acute (less than two weeks after injury) fracture of one or more orbital walls. Eight cases represented delayed reconstruction of orbital walls for late enophthalmos or for residual defects after previous operations. RESULTS: A PPCI provides a stable platform for orbital soft tissue. Excellent results were obtained in all patients with acute orbital fractures, whereas good or excellent corrections of enophthalmos and hypoglobus were achieved in all patients who underwent late repair. There were no instances of orbital infection, implant exposure or migration, worsening diplopia, visual loss, or loss of structural support during 31 months of follow-up. CONCLUSIONS: A PPCI allows controlled placement of a porous polyethylene sheet with secure fixation to stable bone. The implant design allows it to be cantilevered from the orbital rim to serve as a stable platform when fractures are too large to support the implant in the posterior orbit. PPCIs are ideally suited for reconstruction of defects resulting from displacement of orbital walls and for repair of posterior floor fractures, medial wall fractures, and combined floor and medial wall defects.

Primary diffuse chiasmatic germinomas: differentiation from optic chiasm gliomas.

Primary germ cell tumors confined to the optic nerves and chiasm without suprasellar extension are uncommon. These tumors appear similar to chiasmatic gliomas on both computed tomography and magnetic resonance imaging, potentially resulting in treatment errors if the diagnosis is based on radiologic criteria alone. Unlike chiasmatic gliomas, suprasellar germinomas characteristically present with a clinical triad of endocrine abnormalities, diabetes insipidus, and visual complaints. We report the case of a 9-year-old boy who presented with a 5-month history of fatigue, 16-pound weight gain, polydipsia, polyuria, visual complaints, and intermittent headache. Imaging studies demonstrated findings consistent with a glioma of the chiasm with infiltration into the optic tracts. At surgery, the chiasm and optic tracts were diffusely enlarged with no other suprasellar abnormalities. Biopsy specimens were characteristic of germ cell tumor. Based on this result, the patient received a treatment regimen different from that used at our institution for chiasmatic gliomas. We feel it is imperative to biopsy chiasmatic lesions that radiologically appear to be gliomas if symptoms do not adhere to the classical clinical presentation.

A prospective, randomized comparison of thermal cautery and argon laser for permanent punctal occlusion.

Permanent punctal occlusion was performed by two techniques on 27 patients (73 puncta). Patients were randomly assigned to be treated with either thermal cautery or argon laser for keratitis sicca. Follow-up assessment disclosed that the puncta to which thermal cautery was applied remained closed significantly longer than those to which laser treatment was applied (P < .05, log-rank test). Using time to recanalization of a punctum as the end point, we found a long-term advantage of thermal cautery over argon laser treatment.

Orbital paraganglioma: case report and review of the literature.

Paragangliomas of the orbit are extremely rare. A case of an orbital paraganglioma, including the first magnetic resonance imaging description of this tumour is described here. The patient underwent surgery with gross total removal of the tumour and relief of his initial chief complaint of visual blurring. The differential diagnosis and therapeutic options for the management of this tumour are discussed.

Disappearing optociliary shunt vessels and neonatal hydrocephalus.

This is a report of two cases of optociliary shunt vessels in patients with neonatal hydrocephalus. Complete disappearance of the optociliary shunt vessels occurred after surgical procedures to normalize intracranial pressure. The clinicopathological significance, prognosis, and treatment of patients with acquired optociliary shunt vessels is discussed. This is also the first report of the association of optociliary shunt vessels and neonatal hydrocephalus.