AIM:To evaluate the effect of rigid gas permeable(RGP)lens on the tear film and the visual quality in adolescents with a double-pass system.

METHODS:This was a prospective study comprised 23 myopia patients(39 eyes)wearing rigid gas permeable contact lens(RGP)between Jun.2015 and Aug.2015 in the Department of Ophthalmology of Jinling Hospital. Uncorrected visual acuity(UCVA), sphere refractive, cylinder refractive, Schirmer I test, tear film break-up time(BUT), the visual quality and the tear film quality with OQAS II were obtained before and 1wk, 1, 3, 6mo after wearing. The data was analyzed using t-test and One-way.

RESULTS:The UCVA in before and after 1wk, 1, 3, 6mo were 0.23±0.10, 0.81±0.23, 0.99±0.11, 1.01±0.09, 0.95±0.14, the difference was statistically significant(F=723.36, P<0.01). The sphere in before and after 1wk, 1, 3, 6mo were(-2.83±1.34)D,(-0.63±0.82)D,(-0.12±0.20)D,(-0.03±0.10)D,(-0.10±0.30)D respectively, the difference was statistically significant(F=107.01, P<0.01). The refractive cylinder in before and after 1wk, 1, 3, 6mo were(-0.12±0.21)D,(-0.13±0.22)D,(-0.12±0.21)D,(-0.14±0.26)D,(-0.21±0.27)D respectively, there was no significant difference before and after wearing RGP(F=2.58, P>0.05). Schirmer I test showed no statistically significant difference before and after wearing RGP(F=4.88, P>0.05). The stability of tear film was reduced after wearing RGP, and the difference was statistically significant(F=135.11, P<0.01). The modulate transfer function(MTF)cut-off frequency was reduced after wearing RGP, the object scatter index(OSI)was increased after wearing RGP, and the difference was statistically significant, the tear film quality OSI was increased after wearing RGP, and the difference was statistically significant(F=6.16, 19.23, 10.62, P<0.01).

CONCLUSION:The UCVA is significantly increased after wearing RGP. However, there was no significant change in the base-line of tear secretion, but BUT is significantly reduced after wearing RGP. The stability of the tear film is reduced, which can lead to a decline in visual quality.