Thomas R. Hedges

Optical coherence tomography of the retinal nerve fibre layer in mild papilloedema and pseudopapilloedema

Aims: To determine the degree to which optical coherence tomography (OCT) can distinguish differences in retinal nerve fibre layer (RNFL) thickness between eyes with mild papilloedema, pseudopapilloedema, and normal findings. Methods: 13 patients with mild papilloedema, 11 patients with congenitally crowded optic nerves, and 17 normal subjects underwent neuro-ophthalmic examination, automated visual field testing, and fundus photography. Spinal fluid pressure measurements were obtained in a subgroup of five patients with pseudopapilloedema and 11 patients with mild papilloedema. Circular OCT scans using a diameter of 3.38 mm surrounding the optic disc were performed in each eye of patients and subjects. Fundus photographs were analysed by two observers who diagnosed crowding or papilloedema and graded amounts of swelling. Findings were assessed by descriptive statistics and variance analysis. Results: RNFL thickness was greater in the superior and inferior quadrants and showed a high degree of correlation between each group of patients and subjects. A statistically significant difference was found in mean RNFL thickness between both groups of patients with optic disc swelling and normal subjects. However, there was not a statistical difference in mean nerve fibre layer thickness between patients with papilloedema and those with congenitally crowded optic nerves. Conclusions: OCT demonstrates measurable differences in nerve fibre layer thickness between normal subjects and patients with either papilloedema or pseudopapilloedema. However, OCT does not appear to differentiate between those individuals with congenitally crowded optic nerves and those with mild papilloedema caused by increased intracranial pressure.

Effect of optic nerve head drusen on nerve fiber layer thickness

OBJECTIVE The purpose of the study was to evaluate the effect of optic nerve head drusen (ONHD) on nerve fiber layer (NFL) thickness by visual field testing, red-free photography of NFL, and optical coherence tomography (OCT). DESIGN The study design was a prospective clinical study. PARTICIPANTS Twenty-three eyes of 15 consecutive patients with ONHD and 27 eyes of 27 age-matched control subjects participated. INTERVENTION Ophthalmologic examination, color and red-free photography, automated Humphrey visual field testing, and OCT were performed. Each of the drusen study eyes were graded on a scale of 0 to III based on the amount of visible ONHD. Grade 0 represented the absence of clinically visible ONHD, and grade III represented an optic nerve head with abundant drusen. MAIN OUTCOME MEASURES Findings from clinical evaluation and color optic nerve head photographs and NFL evaluation by red-free photography, visual fields, and OCT were measured. RESULTS The number of study eyes with visual field defects increased with the higher grade drusen discs, corresponding both with progressively thinner NFL measurements by OCT and NFL loss shown by NFL photography. The NFL evaluation showed NFL thinning by red-free photography in 12 (71%) of 17 eyes with visible drusen (grades I-III discs) and visual field defects in 9 (53%) of 17 eyes in this group. By OCT measurements, the superior and inferior NFLs were significantly thinner in the eyes with visible ONHD compared with those of control eyes in the superior quadrant (P < 0.001) and inferior quadrant (P = 0.004). Compared with grade 0 discs, grades I through III discs showed statistically significant thinning of the NFL superiorly (P < 0.001). No statistical significant thinning of the NFL was seen in grade 0 discs compared with those of control subjects. CONCLUSIONS Optical coherence tomography is able to detect NFL thinning in eyes with ONHD and appears to be a sensitive and early indicator of NFL thinning. Increased numbers of clinically visible ONHD correlated with NFL thinning shown by OCT measurements and both visual field defects and NFL loss seen by red-free photography.

Neuro-ophthalmologic manifestations of lyme disease

Lyme disease is a tick-borne spirochetal infection characterized by skin rash, neurologic, cardiac, and arthritic findings. The authors report six patients with Lyme disease who had neuro-ophthalmologic manifestations. One patient had meningitis with papilledema, two had optic neuritis, and one had neuroretinitis. Three patients had sixth nerve paresis, two of whom cleared quickly, whereas multiple cranial nerve palsies and subsequent optic neuropathy developed in another. Early recognition of neuro-ophthalmologic findings can help in the diagnosis and treatment of Lyme disease.

Temozolomide in the treatment of an invasive prolactinoma resistant to dopamine agonists

Prolactinomas are common tumors of the anterior pituitary gland. While conventional therapies, including dopamine agonists, transsphenoidal surgery and radiotherapy, are usually effective in controlling tumor growth, some patients develop treatment-resistant tumors. In this report, we describe a patient with an invasive prolactinoma resistant to conventional therapy that responded to the administration of the alkylating agent, temozolomide.

Parasellar and orbital apex syndrome caused by aspergillosis

Patients with orbital aspergillosis commonly present with unilateral proptosis and associated sinus disease. However, neither of these manifestations was observed in a 62-year-old woman who had an orbital apex syndrome with visual loss, complete ophthalmoplegia, and corneal hypoesthesia. Pathologic examination of a specimen from a granulomalike mass removed at left frontotemporal craniotomy showed branching hyphae with the characteristic appearance of Aspergillus.

Optical coherence tomography of the retina: applications in neurology.

Purpose of reviewThis review summarizes the mechanisms and recent developments of optical coherence tomography and its practical uses in neurology. The application of optical coherence tomography imaging of the retina in multiple sclerosis, neuromyelitis optica, Alzheimer disease, and Parkinson disease are reviewed. Recent findingsThinning of the peripapillary retinal nerve fibre layer has been detected in patients with optic neuritis, multiple sclerosis, neuromyelitis optica, Alzheimer disease, and Parkinson disease. However, the patterns of change differ in some aspects. SummaryThe findings indicate loss of retinal ganglion cells and may reflect degenerative change in the brain in these conditions. The retinal nerve fibre layer thickness may be used as a biological marker and may help to distinguish between optic neuritis associated with multiple sclerosis and optic neuritis in neuromyelitis optica.

Color Doppler Imaging of Normal Orbital Vasculature

BACKGROUND Color Doppler imaging has become a useful adjunctive tool in diagnosing ophthalmic vascular disease. However, a paucity of information exists regarding normal values. This investigation was conducted to generate a database of normal retrobulbar circulatory parameters. METHODS The authors prospectively studied the retrobulbar hemodynamic parameters of 53 normal eyes from 32 healthy individuals of various ages, all without risk factors for the development of systemic vascular disease. Preliminary Doppler spectral analysis was used to demonstrate normal carotid arterial, carotid siphon, and ophthalmic vascular anatomy. RESULTS Mean hemodynamic values were recorded for each retrobulbar vessel. Diastolic blood pressure significantly correlated with ophthalmic arterial end-diastolic velocity (P < 0.05) and pulsatility index (P < 0.05). Although end-diastolic velocity significantly decreased (P < 0.05) and vascular resistance significantly increased (P < 0.05) as a function of age in the posterior ciliary and central retinal arterial circulation, no such correlation was identified in the ophthalmic artery which demonstrated significantly more hemodynamic variability among individuals (P < 0.00001). No significant differences in blood flow or vascular resistance were noted between sexes, fellow orbits, or the nasal and temporal branches of the posterior ciliary artery within individual orbits. CONCLUSION Orbital hemodynamic parameters do not appear to be sex dependent or variable between fellow orbits. These data suggest that age and diastolic blood pressure may affect normal orbital blood flow and vascular resistance patterns. Significant interindividual variability is limited only to ophthalmic arterial blood flow.

Subretinal Fluid From Anterior Ischemic Optic Neuropathy Demonstrated by Optical Coherence Tomography

OBJECTIVE To demonstrate the development of subfoveal fluid associated with optic disc swelling from nonarteritic anterior ischemic optic neuropathy. METHODS Optical coherence tomographic studies obtained during a 3-year period (October 1, 2003, to December 30, 2006) from 76 patients who developed ischemic optic neuropathy from 2 institutions were evaluated. The presence or absence, and the distribution, of subretinal fluid was determined. RESULTS Seventy-six patients underwent macular optical coherence tomography within 4 weeks of developing sudden loss of vision in one eye, decreased visual acuity, a visual field defect, a relative afferent pupillary defect, and optic disc swelling with peripapillary hemorrhages. Eight patients had apparent subretinal fluid extending into the subfoveal space. Visual acuity improved in 5 of the 8 patients as the subfoveal fluid resolved. CONCLUSIONS Subretinal fluid develops in some patients with nonarteritic anterior ischemic optic neuropathy and may contribute to some of the visual loss associated with this condition. Furthermore, resolution of the subretinal fluid could account for some of the visual improvement that can follow anterior ischemic optic neuropathy.

The Progression of the Ocular Abnormalities of Herpes Zoster: Histopathologic Observations of Nine Cases

The ocular pathologic findings from nine patients who suffered from herpes zoster ophthalmicus are described. Autopsy material from four patients who died within weeks of the illness and ocular specimens from five patients who required surgery for complications of the disease months to years later demonstrated how the ocular abnormalities caused by zoster may progress in severity with time. The changes ranged from superficial keratitis and mild uveitis to severe granulomatous inflammation of the ciliary body, choroid, and optic nerve within the first several weeks of the disease. In some instances damage secondary to vasculitis predominated, and in others inflammation directly involved ocular tissue. In some chronically affected eyes, granulomatous reaction to Descemets membrane persisted for years, whereas in others the inflammatory reaction apparently resolved, allowing successful penetrating keratoplasty to be performed in one case.

Optic Nerve Decompression Improves Hemodynamic Parameters in Papilledema

PURPOSE The purpose of this study is to examine changes in color Doppler imaging parameters before and after optic nerve sheath decompression (ONSD) for chronic papilledema caused by pseudotumor cerebri (PTC). METHODS Color Doppler imaging was performed within 48 hours before surgery and within 48 hours after the procedure using a color Doppler unit with a 7.5-MHz phased linear transducer. Pulsed Doppler spectrum analyses were recorded digitally on videotape from the ophthalmic, central retinal, and short posterior ciliary arteries, using a 0.4 x 0.6-mm sample volume. RESULTS Blood flow velocities in the ophthalmic, short posterior ciliary, and central retinal arteries of 24 eyes were significantly decreased compared with a healthy age-matched group. Eyes with visual acuities worse than 20/30 before surgery had significantly decreased velocities in the ophthalmic, short posterior ciliary, and retinal arteries, whereas in eyes with visual acuities better than 20/30, only the short posterior ciliary and central retinal arteries demonstrated decreased velocities. In addition, Goslings pulsatility index was increased for the central retinal artery but not the ophthalmic or short posterior ciliary arteries. Thirteen eyes improving in visual acuity and field after ONSD demonstrated significant improvement in all color Doppler imaging parameters for the short posterior ciliary arteries. The ophthalmic artery diastolic velocity also increased significantly but the central retinal artery parameters did not change. The eyes that remained stable or worsened did not demonstrate significant postoperative changes. CONCLUSION These results suggest that some of the visual loss from chronic papilledema may be due to ischemia, and worsening visual acuity correlates with greater impairment of the retrobulbar circulation. One of the mechanisms by which ONSD improves visual function may be reversal of this ischemic process.