Bilateral retinoschisis in a dog: A veterinary clinical application for optical coherence tomography.

A 11-year-old neutered male Labrador retriever-cross dog was presented to the University of Missouri-Columbia Veterinary Ophthalmology Service for subtle visual deficits. Indirect ophthalmoscopy revealed a smooth, bullous elevation in the superior-temporal retina OU. Optical coherence tomography (OCT) performed OU showed inner retinal separation consistent with retinoschisis. Electroretinography (ERG) revealed markedly reduced b-wave amplitudes in the more severely affected eye (OD) compared with the less severely affected eye (OS). The most notable reductions were in the rod response and 30-Hz flicker b-waves OD which were approximately 50% of the corresponding amplitudes OS. Implicit times, particularly the a-wave implicit times, were noticeably longer OD compared with OS. Lesions remained unchanged over 4 months at which time the dog was humanely euthanized for reasons unrelated to the ocular disease. Significant light microscopic ocular findings were bilateral superior temporal peripheral retinoschisis. The separation of the retinal tissue was similar between eyes and effectively divided the outer plexiform layer. In addition, thinning of the surrounding retinal layers was present. To the authors' knowledge, this is the first case of canine retinoschisis diagnosed with OCT, evaluated with electroretinography, and confirmed with light microscopic examination. History, clinical, and diagnostic findings, with the absence of disease progression over time, are analogous with cases of acquired senile retinoschisis in humans.

Neurophysiological assessment of auditory, peripheral nerve, somatosensory, and visual system function after developmental exposure to gasoline, E15, and E85 vapors.

The use of gasolines blended with a range of ethanol concentrations may result in inhalation of vapors containing a variable combination of ethanol with other volatile gasoline constituents. The possibility of exposure and potential interactions between vapor constituents suggests the need to evaluate the possible risks of this complex mixture. Previously we evaluated the effects of developmental exposure to ethanol vapors on neurophysiological measures of sensory function as a component of a larger project evaluating developmental ethanol toxicity. Here we report an evaluation using the same battery of sensory function testing in offspring of pregnant dams exposed during gestation to condensed vapors of gasoline (E0), gasoline blended with 15% ethanol (E15) or gasoline blended with 85% ethanol (E85). Pregnant Long-Evans rats were exposed to target concentrations 0, 3000, 6000, or 9000 ppm total hydrocarbon vapors for 6.5h/day over GD9 - GD20. Sensory evaluations of male offspring began as adults. The electrophysiological testing battery included tests of: peripheral nerve (compound action potentials, nerve conduction velocity [NCV]), somatosensory (cortical and cerebellar evoked potentials), auditory (brainstem auditory evoked responses), and visual functions. Visual function assessment included pattern elicited visual evoked potentials (VEP), VEP contrast sensitivity, dark-adapted (scotopic) electroretinograms (ERGs), light-adapted (photopic) ERGs, and green flicker ERGs. The results included sporadic statistically significant effects, but the observations were not consistently concentration-related and appeared to be statistical Type 1 errors related to multiple dependent measures evaluated. The exposure concentrations were much higher than can be reasonably expected from typical exposures to the general population during refueling or other common exposure situations. Overall the results indicate that gestational exposure of male rats to ethanol/gasoline vapor combinations did not cause detectable changes in peripheral nerve, somatosensory, auditory, or visual function when the offspring were assessed as adults.

Neurophysiological assessment of auditory, peripheral nerve, somatosensory, and visual system functions after developmental exposure to ethanol vapors.

Ethanol-blended gasoline entered the market in response to demand for domestic renewable energy sources, and may result in increased inhalation of ethanol vapors in combination with other volatile gasoline constituents. It is important to understand potential risks of inhalation of ethanol vapors by themselves, and also as a baseline for evaluating the risks of ethanol combined with a complex mixture of hydrocarbon vapors. Because sensory dysfunction has been reported after developmental exposure to ethanol, we evaluated the effects of developmental exposure to ethanol vapors on neurophysiological measures of sensory function as a component of a larger project evaluating developmental ethanol toxicity. Pregnant Long-Evans rats were exposed to target concentrations 0, 5000, 10,000, or 21,000 ppm ethanol vapors for 6.5h/day over GD9-GD20. Sensory evaluations of male offspring began between PND106 and PND128. Peripheral nerve function (compound action potentials, nerve conduction velocity (NCV)), somatosensory (cortical and cerebellar evoked potentials), auditory (brainstem auditory evoked responses), and visual evoked responses were assessed. Visual function assessment included pattern elicited visual evoked potentials (VEPs), VEP contrast sensitivity, and electroretinograms recorded from dark-adapted (scotopic), light-adapted (photopic) flashes, and UV flicker and green flicker. No consistent concentration-related changes were observed for any of the physiological measures. The results show that gestational exposure to ethanol vapor did not result in detectable changes in peripheral nerve, somatosensory, auditory, or visual function when the offspring were assessed as adults.

Funduscopic and angiographic appearance in the neuronal ceroid lipofuscinoses.

PURPOSE: To characterize the retinal features of neuronal ceroid lipofuscinoses (NCLs) and to determine if retinal abnormalities are detectable in carriers of these autosomal recessively inherited diseases. METHODS: Carriers of the NCLs and their affected children underwent ophthalmic examination including color fundus photography in all patients and fluorescein angiography in selected patients. Twenty-nine patients with NCL were examined and photographed: 3 with infantile form, 2 with late-infantile form, and 24 with juvenile form. Fourteen patients underwent fluorescein angiography. RESULTS: Infantile and late-infantile retinal findings include fine retinal pigment epithelium pigment atrophy with no bone spicule changes and disk pallor. Juvenile retinal findings include macular retinal pigment epithelium atrophy and pigment stippling (>50%), epiretinal membrane (33%), bull's eye maculopathy (25%), and peripheral bone spicules (46%) and variable disk pallor. Fluorescein angiography of juvenile patients demonstrated diffuse retinal pigment epithelium atrophy with stippled hyperfluorescence (93%). Heterozygous NCL carriers had no identifying retinal abnormalities. CONCLUSION: Significant variability exists in the retinal appearance of the NCLs, but, in general, ophthalmoscopy and fluorescein angiography distinguish these patients from other more common blinding disorders of childhood such as retinitis pigmentosa and Stargardt disease. Examining retinas of parents of affected children does not aid in the diagnosis of NCL.

Interpretation of flow cytometric measurement of lymphocytes after fluorescein angiography.

PURPOSE: By use of flow cytometry (FCM), lymphocyte subsets were evaluated with fluorochrome-labeled monoclonal antibodies (MoAbs). Recent fluorescein angiography (FA) produces temporary elevation of serum background fluorescence at certain wavelengths of light, producing falsely decreased lymphocyte subset quantitations. The authors evaluated the duration of this effect on one subset of lymphocytes after FA. METHODS: CD4 counts were determined by FCM before and 10 minutes, 1, 6, and 24 hours after injection of fluorescein dye in 12 patients. The MoAbs used were directly conjugated to fluorescein isothiocyanate (FITC) or phycoerythrin (PE). RESULTS: Using FITC-labeled MoAbs, falsely decreased CD4 counts occurred in all patients at 10 minutes and in all but one patient 1 hour after injection. Return to baseline levels occurred in 50% (95% confidence interval [CI], 0.21, 0.79) by 6 hours and in 75% (95% CI, 0.43, 0.95] by 24 hours. No such effect was observed using PE-labeled MoAbs. CONCLUSIONS: Falsely decreased CD4 values as determined by FCM were present immediately after FA in all 12 patients and persisted 24 hours in some patients when FITC-labeled MoAbs were used. CD4 evaluation should be delayed in patients who have undergone recent FA or the analysis should be performed with PE-labeled MoAbs.