Tear ascorbic acid levels and the total antioxidant status in contact lens wearers: a pilot study.
OBJECTIVE
The tear ascorbate owing to its high concentration, functions as an effective antioxidant against the oxidative damage of cornea. Contact lens wearers (CLW) are prone to oxidative stress due to the lens-induced hypoxic conditions. A pilot study was done to compare the tear ascorbic acid level and the total antioxidant capacity give as in normal and CLW.


METHODS
In this study 21 CLW (Mean age 23 +/- 3 years ; M-2, F-19), who were daily wear users, with duration of wear not more than four years, along with age-matched 28 controls (Mean age 28 +/- 3 ; M-15, F-13) were recruited in the study for collection of reflex tears using Schirmer's strip. Ascorbic acid in tears was determined using high-performance liquid chromatography (HPLC), total antioxidant capacity (TAC) and total protein assay by spectrophotometric analysis.


RESULTS
CLW showed no significant change in the tear ascorbic acid levels (0.4 +/- 0.26 mM) compared to the control subjects (0.61 +/- 0.59 mM). The amount of ascorbic acid in tears did not correlate with the TAC or the total protein of the tears. The mean TAC in CLW was 0.69 +/- 0.16 mM, with a total protein of 1.35 +/- 0.46 mg/ml while in controls it was 0.7 +/- 0.18 mM and 1.21 +/- 0.47 mg/ml respectively.


CONCLUSIONS
Soft contact lens wear did not show any significant change in tear ascorbic acid, TAC and total protein levels compared to controls.
Venkata
Sai Jyothi Aluru
SJ
Biochemistry Research Department, Sankara Nethralaya, Vision and Medical Research Foundation, 18 College Road, Chennai, India.
Narayanasamy
Angayarkanni
A
Srinivasan
Vidhya
V
Iyer
Geetha Krishnan
GK
Sivaramakrishnan
Ramakrishnan
R
Subramanian
Madhumathi
M
Mahadevan
Rajeshwari
R
D000975:Antioxidants / Q000032:analysis*; D001205:Ascorbic Acid / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D003263:Contact Lenses, Hydrophilic; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects; D011506:Proteins / Q000032:analysis; D013053:Spectrophotometry; D013666:Tears / Q000737:chemistry*; D055815:Young Adult
D000975:Antioxidants; D011506:Proteins; D001205:Ascorbic Acid