Characteristics Of The Tear Film According To Gender, In A Healthy Young Myopic Population.

To determine the possible differences between genders in tear stability and osmolarity, in a population of healthy myopic patients.

Prospective, observational study. Clinica Novovision Madrid, Spain

68 healthy myopic patients with a normal OSDI test, candidates to refractive surgery were classified in two groups according to their gender. 34 patients (68 eyes) in the male group, and 34 patients (68 eyes) in the female group. Their tear film was evaluated using the Keratograph in addition to their tear osmolarity (Tear Lab).

Both groups (male/female) were comparable in terms of age (29.5+/-6.0 vs 28.3+/-4.7 p=0.2), with no statistically significant difference in OSDI test (9.7+/- 10.0 vs 7.3+/-13.2 p=0.07). A statistically significant higher tear stability was observed in the male group, both in the initial NIKBUT (13.9+/-7.9 vs 10.9 +/-7.0 sec p=0.02) and mean NIKBUT (16.0+/-7.2 vs 13.3+/- 6.8 sec p=0.02), male vs female respectively. No statistically significant differences were observed in the tear osmolarity (303.6+/-16.3 vs 301.0+/-11.1 mOsm/L p=0.2).

The current study shows higher tear stability in males than in females. Although we did not find statistically significant differences in the dryness symptoms test, we did observe a tendency towards a worse value in the OSDI in females, perhaps related to their lower tear stability. This difference may indicate that there may be gender factors that influence tear stability and thus predispose females to have more dry eye symptoms.