The differential diagnosis of visual disorders in patients presenting with marked symptoms but with no observable ocular abnormality

A differential diagnosis of nine conditions which sometimes produce distressing symptoms without overt signs is presented. Sophisticated tests, especially electrodiagnostic ones, can aid the optometrist in making the correct decision. The selected procedures and the expected results are summarized in a table. The conditions reviewed are Stargardt's macular degeneration, Leber's congenital amaurosis, albinism, foveal hypoplasia, retinitis pigmentosa, retrobulbar neuritis, amblyopia, and problems of psychogenic origin.

Advanced diagnostic procedures for evaluating the visual status of the child

Single cell studies of cats and monkeys, recent behavioral testing methods, and improved sophisticated electrodiagnostic procedures have resulted in a new awareness of and concern for the development of the visual system. This paper will review select relevant research and highlight some of the new diagnostic vision tests presently available for the clinical assessment of infants and young children.

An embedded contact lens in the upper lid masquerading as a mass

A patient who "lost" his right contact lens three years prior to our examination was found to have a mass in the right upper lid which contained the hard contact lens. A careful search of the superior fornix and the upper lid, with double eversion of the lids, is indicated in instances where a patient presents reporting loss of a lens he was wearing or inserting.

Electro-oculography, dark adaptometry, and laser interferometry

This paper discusses the basic concepts of electrooculography (E.O.G.), dark adaptometry, and laser interferometry. Included is the clinical relevance of each procedure.

Epidemiology of equine upper respiratory tract disease on standardbred racetracks

The outbreaks of upper respiratory tract infections in horses at Standardbred racetracks were investigated over a three year period. The most serious epidemics of respiratory disease occurred in the winter and spring seasons. Both influenza viruses and equine herpesvirus 1 were shown to be present in the horse population. The herpesvirus was associated with respiratory disease particularly in the winter but the equine influenza viruses apparently were responsible for the major epidemics of respiratory disease at these tracks. Younger horses, two or three years of age, were particularly susceptible to upper respiratory disease and showed the greatest rate of seroconversion to influenza viruses. Major outbreaks of respiratory disease occurred when the proportion of young horses which had not previously been exposed to epidemics of respiratory disease reached 30 to 40% of the population at the track. Most horses over four years of age appeared to develop resistance to the infections.

Fundus fluorescein angiography: a summary of theoretical concepts and clinical applications

The basic concepts of fundus fluorescein angiography are presented along with historical and physiological background. Fundus photographs, as well as angiograms, are used to highlight the text.

Visual evoked potential (VEP): basic concepts and clinical applications

The Visual Evoked Potential is the objective measurement of visual function monitored at the level of the occipital cortex with scalp electrodes. This article summarizes many of the recent clinical applications of the VEP. Included are basic concepts of the VEP and its clinical utilization for the objective assessment of refractive error, visual acuity, amblyopia, binocularity, demyelinating diseases, psychogenic disorders, pre-surgical prediction of post-surgical visual function, visual fields, color blindness and neurological development.

Static vs dynamic visual field evaluation; with emphasis on the utility of the Friedmann Visual Field Analyzer

This paper contrasts static and dynamic perimetry, highlighting the advantages and disadvantages of each. A type of static perimetry, the Friedmann Visual Field Analyzer, is discussed in some detail. A clinical study, comparing the sensitivity of the Friedmann Visual Field Analyzer and B&L Autoplot in detecting field defects in known glaucoma patients, is presented. The results of this study support the notion that static fields (utilizing the FVFA) are significantly more sensitive than dynamic fields (utilizing the B&L Autoplot) in detecting field defects in known glaucoma patients.

Prevalence of glaucoma in optometric patients under 40 years of age

A survey of 3,494 patients under 40, who were examined in an urban optometric center, showed that 0.4% of the sample had glaucoma and an additional 0.2% had suspected glaucoma. The clinical implications of glaucoma in persons under 40 are discussed.

Infectious causes of equine respiratory disease on Ontario standardbred racetracks

Upper respiratory disease has been a serious problem in Standardbred horses on racetracks in Ontario, with outbreaks occurring once or twice annually in late winter and early spring seasons. To determine the causes of these epidemics, a 3-year investigation was carried out in which nasal swabs and serum samples were obtained at intervals from apparently healthy horses and from horses suffering from upper respiratory disease. The nasal swabs were used to isolate bacteria and viruses. The serum samples were examined for the presence and level of antibodies to equine influenza viruses and equine herpesvirus 1. None of the bacteria isolated were associated with the outbreaks of disease. Equine herpesvirus 2 was isolated 72 times from both diseased and apparently healthy horses. Equine herpesvirus 1 was isolated 10 times from horses with respiratory disease, both during and between epidemics. Influenza equine/1 virus was isolated seven times and influenza equine/2 was isolated once during severe outbreaks of upper respiratory disease. Serological evidence confirmed that influenza viruses were the causes of the major epidemics, with the equine/1 strain being involved most often.

Effects of preanesthetic medication, anesthesia, and position of recumbency on central venous pressure in horses

Central venous pressure (cvp) was recorded in horses before and after tranquilization and during halothane-maintained anesthesia in lateral or dorsal recumbency. The cvp was significantly decreased after administration of acetylpromazine, when compared with base line measurements and measurements taken after xylazine administration. After induction of anesthesia, cvp increased with time for 75 minutes, and values in lateral recumbency were significantly higher than those in dorsal recumbency.

PRIMARY CARCINOMA OF THE LUNG

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