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At least 1,531 records · Page 85Linked to original sources
PubMed1985

Environmental influence on shape of the crystalline lens: the amphibian example.

Amphibians are faced with the problem of adapting to aerial vision when undergoing metamorphosis. The rate and extent of ocular change has been examined in five species with widely varying life histories. Ocular effects and in particular lens shape changes were determined from measurements of gross anatomy at various metamorphic stages using a freeze-sectioning technique. In addition, refractive states were measured retinoscopically in air and water where possible. All larval animals have the ocular structure and optics typical of teleost fish. Adults show varying levels of adaptation to aerial vision, depending on the degree of departure from an aquatic style of behavior. In certain cases the spherical aquatic shape of the lens is maintained while in others, lens shape is altered markedly to a flattened elliptical form. Histological study indicates that change in lens shape is brought about by a rapid increase of mitotic activity of equatorial epithelial cells at critical periods during metamorphosis.

Adaptation, Physiological↗
PubMed1985

Estimation of urine flow rate in mares.

To determine the rate of urine flow and thus urinary excretion in the horse from untimed urine samples alone, the flow rate, creatinine concentration, osmolarity, and refractive index of 228 quantitatively collected urine samples were determined in 53 experiments on 12 healthy Thoroughbred mares. Forty samples were collected after water-induced diuresis; 11 samples were collected after furosemide-induced diuresis. Flow rates, which ranged from 1.2 to 84.5 ml/min, could be predicted from the urinary creatinine concentration. Correlation of urinary flow with urinary creatinine concentration accounted for 94% of the variability in the urinary flow rates. Phenylbutazone was administered before collection of 168 urine samples. Urine flow rates that were predicted from urinary creatinine concentration were used to estimate phenylbutazone excretion. Urine flow could be estimated without quantitative urine collection.

Animals↗
PubMed1985

Effect of diuresis on urinary excretion and creatinine clearance in the horse.

Endogenous creatinine clearance and renal excretion of phenylbutazone, osmotically active material, and compounds contributing to the urinary refractive index were studied in 12 Thoroughbred mares after no treatment, after water administration, or after furosemide administration. Urine was quantitatively collected, using urinary bladder catheters. On average, urine flow of the mares was 9 microliters/min/kg without treatment and increased to about 50 microliters/min/kg after water administration and to about 70 microliters/min/kg after furosemide administration. Water administration increased creatinine clearance values and excretion of phenylbutazone. Furosemide administration increased urinary excretion of osmotically active compounds and compounds contributing to urinary refractive index and decreased excretion of phenylbutazone.

Animals↗
PubMed1985

[Ophthalmological symptoms of infantile cerebral palsy].

136 patients with infantile cerebral palsy (C.P.) aged between 9 months and 24 years were examined in a special ophthalmology clinic for disabled children. 56% revealed strabismus, which was accompanied by variation in the concomitant squint angle and/or nystagmus in over two thirds of the cases. Strabismus divergens is over 3 times more frequent than in normally developed children. Strabismus in C.P. is more or less independent of the stage of refraction. There is no connection between the different types of C.P. and the various forms of strabismus. 6% of the cerebral paretic children showed gaze palsy combined with nystagmus on attempting to look down.

Adolescent↗
PubMed1985

A metabolic aspect of high myopia.

Abnormal zinc and copper metabolism has been described in some retinal disorders affecting the retinal pigment epithelium. Anatomic studies in high myopic eyes, show important changes in this retinal layer. We examined the blood for zinc and copper and urine for copper in different groups of high myopic black and white patients, and high myopic white patients with primary retinal detachment. In the white myopic groups, many of the patients showed high serum zinc and low serum copper values. In the high myopic patients with primary retinal detachment, the serum zinc and copper were found to be distinctly elevated and of statistical significance. A relative inverse copper/zinc ratio between the concentration of these metals in serum and their concentration in the subretinal fluid was noted as well. The significance of these findings and their connection to the retinal pigment epithelium is discussed.

Adult↗
PubMed1985

Surgical results of second-attempt radial keratotomy.

The safety, efficacy, and stability of second-attempt radial keratotomy were evaluated in 20 eyes of 12 patients from September 1, 1982, to August 31, 1983. The average amount of refractive error change was 1.89 diopters with 1.38 diopters of corneal curvature flattening. The effect of the second-attempt operation was about 60% that of the first-attempt operation. No significant surgical complications were observed in this study.

Adult↗
PubMed1984

Refractive reconstruction for acute eye injuries.

Acute tissue repair from corneal trauma requires an understanding of basic corneal topography shifts in keratorefractive surgery. Avoiding astigmatism at the time of the initial repair is propitious, but may not be accomplished even with a careful understanding of the vector forces of suture material when tissue is lost from the cornea. Subsequent wound revision, tissue replacement, relaxing incisions or penetrating keratoplasty may be necessary.

Animals↗
PubMed1984

Failure of passive transfer in calves: comparison of field diagnosis methods.

Calves with serum immunoglobulin levels less than 800 mg/dl have a failure of passive transfer of maternal antibodies, those with 800-1600 mg/dl have a partial failure of passive transfer, and those with greater than 1600 mg/dl have adequate immunoglobulin levels. Tests for immunoglobulin level evaluation are most accurate when serum from healthy animals 1-8 days old is used. Of the sodium sulfite precipitation, zinc sulfate turbidity and glutaraldehyde coagulation tests, the first is the most useful field test for evaluation of serum immunoglobulin levels in calves. It is inexpensive, easy to perform and relatively accurate.

Animals↗
PubMed1984

Automated objective refractometers.

We have shown how the modern-day analysis of the aerial image produced by an indirect ophthalmoscope forms the basis for automated objective refraction. Objective automated optometers present with the advantages that they: record rapidly, thereby minimizing the effects of accommodative fluctuation and/or fixation instability, demand only low-level technical skill on the part of the operator, demand little of the patient beyond passive cooperation. Refractive findings obtained using objective automated refractors are counterparts of retinoscopic prescriptions and correlate about as well with subjective findings as do those obtained by the proficient retinoscopist.

Ophthalmoscopy↗
PubMed1984

[Practicable method for preparing and controlling aqueous solutions of potassium bromide with very precise hydratic density].

With a view to realization the conditions of ultrasedimentative isolation of plasma lipoproteins the correlation between density (d4), coefficient of light refraction (nD20) and concentration (0,72-2,77 mol/l) of aqueous KBr solutions were analyzed. The tendency of alteration in nD20 with the change of d4 of KBr solutions have a linear character and the regression line is presented by the equation: nD20 = 1,1783 + 0,1552. It could be concluded from the analysis that the hydratic density of KBr solutions could be rapidly and very precisely controlled via Abbe refractometer at 20 degrees C.

Bromides↗