Diurnal variation in group IIa phospholipase A2 content in tears of contact lens wearers and normal controls

Abstract

In normal subjects, the GIIAPLA(2) content of tears increased from 8 a.m. to noon and decreased from 4 p.m. to 8 p.m. The use of CLs for 4 h and 8 h caused a decrease in the GIIAPLA(2) content of tears. This difference was not seen at 4 p.m. the day when the CL wearers did not use CLs.

Group IIA phospholipase A2 content of tears in patients with atopic blepharoconjunctivitis

“…We have previously shown that the concentration of GIIAPLA 2 decreases in tears of older subjects [19] and contact lens wearers [6], in reflex tears [3], and early in the morning and in the evening [6]. Similarly, the GIIAPLA 2 concentration of tears decreased two days after a PRK operation, although 1 week postoperatively it was higher than preoperatively [5].…”

“…The concentration decreased with increasing age [19], showed a discernible diurnal rhythm [6] and was statistically, significantly lower in reflex than in basal tears [3]. The GIIAPLA 2 concentration of tears was elevated in patients with keratoconjunctivitis sicca [4], whereas in patients with senile cataract or primary open-angle glaucoma the concentration was normal [2].…”

Phospholipids and Their Degrading Enzyme in the Tears of Soft Contact Lens Wearers

“…Instead, we found significant deposition of group IIa sPLA 2 on Etafilcon A contact lenses. Aho et al 36 reported that contact lens wearers had statistically lower group IIa sPLA 2 content in tears at noon and at 4:00 PM versus healthy controls. They proposed that transient low levels of group IIa sPLA 2 observed in contact lens wearers might be caused by contact lens absorption of group IIa sPLA 2 .…”

Tear Analysis and Lens-tear Interactions: Part II. Ocular Lipids—Nature and Fate of Meibomian Gland Phospholipids

“…Contact lenses are known to provide a very effective means of concentrating tear lipids (including phospholipids) in a readily extractable form 23 and yet, phospholipids remain difficult to detect in the tear film. What is the role in the tear film of proteins, such as phospholipases [24][25][26][27] and phospholipid transfer protein, 28 (which are present in the tear film at relatively high concentrations) in relation to phospholipids? Phospholipids are known to have a role in the stability of the tear film.…”