Abstract:AIM: To investigate the effect of intraocular pressure(IOP)fluctuations on the visual performance in steroid responders after laser in situ keratomileusis(LASIK).
METHODS: Fifteen post-LASIK patients who underwent steroid-induced IOP fluctuations were enrolled as study group. And all received effective therapy when identified. Another 15 matched post-LASIK patients who used topical steroids for the same duration without developing hypertension were selected as control group. During the follow-up visits, uncorrected distant visual acuity(UDVA), photopic contrast sensitivity, wavefront aberrations, and corneal topography, were measured. These aimed at comparing the differences in postoperative changes between the groups.
RESULTS: In study group, comparison of preoperative and postoperative IOP, the amplitude of abnormal IOP fluctuations reached 10.6±4.4mmHg(ranged from 21.3 to 32.9mmHg). Compared with postoperative ocular hypertension, statistics demonstrated significant changes such as UDVA, photopic contrast sensitivity, and wavefront aberrations, and corneal topography under the condition of normal tension. 1)UDVA: a significant difference was seen in UDVA between ocular hypertension and normal tension(P<0.001); 2)Contrast sensitivity: results showed significant differences in 3, 6, 12, and 18 cycles/degree of photopic contrast sensitivity(all P<0.05); 3)Wavefront aberrations: statistics indicated significant differences in higher order aberrations(HOA), trefoil and spherical aberration(P<0.05 for all); 4)Corneal topography parameters such as Q-value, difference value(Diff-value)between the posterior corneal surface and the best fit sphere in the central region(Φ=6mm), and central corneal thickness(CCT)showed significant differences(P<0.01 for all). However, in control group, except for the increased CCT with time, no other significant changes were observed during the follow-up visits.
CONCLUSION:Transient abnormal IOP fluctuations might induce remarkable optical and visual changes, and limiting the IOP fluctuations might improve the visual performance in steroid responders after LASIK.