Hydrogen ion concentration of tear fluid in newborn infants

  title={Hydrogen ion concentration of tear fluid in newborn infants},
  author={Helena Dahl and Camilla Dahl},
  journal={Acta Ophthalmologica},
Abstract. Tear pH was measured in 173 newborn infants by immersing the tip of a microcombination glass pH probe in the tear fluid lateral in the closed lower conjunctival sac. The median tear pH value was 6.8 with 95% interpercentile range 6.2 to 7.2. The mean tear pH value was 6.74+0.26 (SD). The pH value was not related to age within the first 12 days and not influenced by the mode of delivery or local application of 0.67% argenti nitratis. This method is an easy, reliable examination to… 

Demonstration of increasing standard pH value of lacrimal fluid with increase of flow rate.

A positive flow rate-pH relationship was found for human tears when the uncertainty was removed by determination of the standard pH.


The tears was significantly more acid in contact lens wearers and significantly more alcaline in lacrimal stenosis and keratitis (mycotic) and the pH-normalisation after instillation of buffer in vivo, delaid in older people, sicca and soft lens wearer.

Infant tear film collection and composition

Tear collection, transport from the clinical location to the laboratory and analysis of tear samples were successfully carried out and no relationship between tear volume and protein analysis was found, but similar to adult tear proteins a relationship with closed and open eye tears was found.

Fluorophotometric measurement of pH of human tears in vivo.

The method described was useful in measuring the pH of the precorneal tear film of humans with minimal invasion and the ratio of fluorescent intensities at two excitation wavelengths (490/430 ratio) was dependent on pH, but independent of the dye concentration and other variables.

pH changes of the tear fluid in the conjunctival sac during postoperative inflammation of the human eye

Conjunctival fluid pH was measured pre‐ and post‐operatively in 16 patients suffering from senile cataract and it is reasonable to assume that the composition of the transudate/exudate from the conjunctival vessels might be responsible for the changes observed.

Tear fluid pH in normals, contact lens wearers, and pathological cases

  • M. Norn
  • Medicine
    Acta ophthalmologica
  • 1988
There was, perhaps, a tendency towards alkalisation in eves with keratoconjunctivitis sicca, whereas the pH was normal in the other pathological states, or the number of cases representing these may be too small.

The neonatal tear film.

Function of meibomian glands and tear pH

Abstract. Each of ten persons had ten meibomian orifices studied by triple‐vital‐staining. Activity was disclosed in 43%, these being stained by lipid‐specific Sudan III power. 5% were stained by

Corneal and conjunctival impression cytology in soft contact lens wearers

Corneal and conjunctional cytology changes worsened with decreasing pH, whereas corneal keratinization showed no significant correlation, and was directly proportional to duration of CL use.

Nasal, Ocular and Otic Drug Delivery

This chapter considers anatomical and physiological differences in children compared to adults such that delivery of medicines at these sites is safe and efficacious at non-invasive routes of administration of drugs.




This study was undertaken to determine whether newborn infants secrete tears, and if there is a pattern in the amount of tear secretion during the first few weeks of life.

Human tear pH. Diurnal variations.

Using a closed chamber microelectrode system, the tear pH levels of sixteen subjects were monitored throughout the waking extent of five days and diurnal patterns of pH change could be identified for the majority.

Normal human tear pH by direct measurement.

Tear pH was measured in 44 normal subjects by immersing the lip of a microcombination glass pH probe in the tear fluid in the inferior cul-de-sac by providing a rapid and accurate measure of tear pH.


  • M. Norn
  • Biology
    Acta ophthalmologica
  • 1968
Various reports are available on investigations into the hydrogen ion concentration of the tear fluid, and some writers claim to have seen a neutral reaction, or more often a slightly alkaline pH value, about that of serum, while others have noticed a still more alkaline reaction.

Human tear PH.

  • M. Norn
  • Medicine
    Archives of ophthalmology
  • 1977
It is concluded that tears are more acid in the morning, taken from a yet unopened eye, than later in the day, according to the average pH, which is higher than the average throughout the day.

External Eye Methods of Examination, 2nd edn. pp 121-131

  • 1983