PubMed Health⌕ Search

Biomedical subjects

M Norn

Publications and source records attributed to M Norn.

11 recordsLinked to original sources
PubMed1992

Pollution keratoconjunctivitis. A review.

In 'sick building syndrome' and other questionable environmental conditions, it is important to consider eye troubles. This review deals with several objective methods relevant for pollution keratoconjunctivitis. A hypothesis is put forward: A reduced lipid layer of the tear film causes reduced break-up time, increased vital staining and increased number of cells in the conjunctival fluid.

Air Pollution, Indoor↗
PubMed1992

Sampling methods for tear stix tests.

Four different methods for transferring conjunctival fluid to stix test pads were studied. One hundred and twenty eyes from 120 cataract-extracted patients (35 in the operated eye 0-5 days post-operatively and 85 in the contralateral eye) were included in the study. Transfer of fluid by a glass rod from the lateral part of the inferior fornix was demonstrated to be the most suitable method, showing the highest sensitivity to leucocyte-esterase (83%, N = 120, p < 0.05) and with a specificity equal to that of the other methods tested (cotton, spongostan, Schirmer paper strip). The glass rod method is suitable for detecting blood, nitrite, albumin, pH, and glucose, and is a both quick and unintrusive procedure. All four transferring methods may, however, cause an increased desquamation of epithelial cells and an increased amount of mucus.

Adult↗
PubMed1991

Quantitative tear meniscus cytology versus quantitative conjunctival fluid cytology.

A technique for quantitative cytology of tear fluid collected by a micropipette from the tear meniscus is presented. This technique has been compared with that using the standardized Norn-pipette collecting fluid from the lateral part of the inferior fornix. The two methods show the same magnitude of sensitivity and specificity, the same coefficient of variation, as regards neutrophilic leucocytes and erythrocytes (200 samples). The normal tear meniscus contains less than 40 leucocytes or erythrocytes per microliter. The tear cell concentration is about 200 times lower in the meniscus than in the fornix inferior in normal eyes. This observation supports the compartment-theory of a rapid flow in the tear meniscus and a slow flow with insignificant admixture in the conjunctival fluid in the fornices. The tear meniscus cytology is of use in association with testing of other parameters in the tears, for instance. The conjunctival fluid cytology is quicker and more convenient for the patient. In addition, it is necessary in connection with observation for pathological epithelial desquamation, because the tear meniscus cytology brings about an artificial increase of the epithelial cell concentration.

Conjunctiva↗
PubMed1991

Occult haemolacria in females.

A series of 125 healthy subjects were examined by the stix method (chemical response) for occult occurrence of blood in tears. Blood was found in 18% of fertile women, definitely most often in the menstrual phase (in 39% of 51 samples within the first week, reckoned from the first day of menstruation). The incidence was independent of use of the contraceptive pill. On the other hand, occult haemolacria was observed in no more than 7% (= 30) of pregnant women and in none at the menopause (N = 7). Among males the phenomenon was noticed in 8% (N = 24). Occult haemolacria in fertile women thus seems to be induced by hormones, whereas haemolacria most often is provoked by local factors (bacterial conjunctivitis, environmental damage, injuries).

Female↗
PubMed1991

Long-term changes in the outer part of the eye in welders. Prevalence of spheroid degeneration, pinguecula, pterygium, and corneal cicatrices.

Biomicroscopical examination of possible cumulative changes in the outer part of the eye in 217 male welders with variable welding exposure time showed conjunctival spheroid degeneration in 24% of the welders. The prevalence of changes was significantly increased in welders with the higher exposure time in an age-matched reduced material (98 x 2 eyes; respectively, over and under 40 h.y (number of daily hours of welding multiplied by number of years of welding), welders with stays abroad over one year being withdrawn. The prevalence was also increased in the latter group (41%, N = 40, against 21%, N = 177). Pinguecula was present in 57% of the welders, with a tendency towards larger area with increasing welding exposure. The frequency was increased as compared with that in a control material examined on a previous occasion (41%). Pterygium proper was found in only one subject, pseudopterygium in 5%. Corneal cicatrices were present in about one half of the subjects. The prevalence increased with increasing welding exposure (24% in subjects with short, 42% in those with long exposure; 98 x 2 eyes). Acute welding light keratopathy was experienced by 73%. The mean number of attacks in the 217 welders was 6.4. The frequency was highest in subjects with long welding exposure. The risk of chronic impairment of sight owing to cumulative welding light injuries is very little in the present material, since only 2% had spheroid degeneration on the cornea (only discrete, peripherally located); there was no preponderance of pterygium. On the other hand, the many foreign bodies on the cornea (cicatrices) constitute a risk that apparently does not decrease with increasing welding experience nor repeated attacks of welding light keratopathy.

Adolescent↗
PubMed1990

[A tear strip test in the control of contact lens wearers].

A series of 86 contact lens wearers has been examined by tear-stix tests (35 wearing hard lenses and 51 soft). Of these, 52 showed no infection (group A), while 34 had signs and/or symptoms of infection (group B). Leucocyte-esterase positivity was seen in 8% of group A and 62% of group B. Stix-positive were 13% of group A and 85% of group B (positive leucocyte-esterase and/or positive nitrite and/or positive hemoglobin). The examinations are quick and easy to carry out, with a reasonable sensitivity and specificity.

Clinical Enzyme Tests↗
PubMed1990

Hudson-Stähli's iron line in the cornea. Occurrence in 1968 and in 1988.

Examination of 700 persons in 1968 showed presence of Hudson-Stähli's iron line in 29%. A similar examination by the same author 20 years later revealed a significantly lower occurrence (18%) and fewer cases of binocular occurrence (70% against 43%). The line is most often horizontal. If oblique, it generally passes from the upper nasal to the lower temporal region.

Adolescent↗
PubMed1985

Meibomian orifices and Marx's line. Studied by triple vital staining.

The ciliary margins of the lower lids have been vital stained by the lipid-specific Sudan III powder, fluorescein 0.1% and the bottom of the lacrimal river (Marx's line) by lissamine green 1% in 100 cases. The Meibomian orifices are situated in a straight row just in front of the Marx's line in the lipid phase. With increasing age (greater than 50 years) the orifices are more often displaced and also discharge their lipid in the depth of the aqueous phase. The number averaged 21.5 in the lipid phase and 1.7 in the aqueous phase. Active orifices staining with lipid were found in 45% of all orifices in normals, independent of age, and were increased in conjunctivitis in the lipid phase. Lissamine green-stained orifices were independent of age, phase and diagnosis. The anterior edge of Marx's line may run an irregular course in elderly normals (greater than 50 years), significantly more often in conjunctivitis and blepharitis.

Adolescent↗