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AIM: To observe effect of the iris location to femtosecond - combined wavefront guided LASIK for myopia and astigmatism.?METHODS:The patients with astigmatism >1. 0D during the same time and followed up for 1a were selected. A total of 129 eyes in 67 patients were treated under iris location with femtosecond-combined wavefront guided LASIK ( experimental group) and 161 eyes in 82 cases with femtosecond-combined wavefront guided LASIK ( control group) . Laser cutting went with the same laser machine. The uncorrected visual acuity ( UCVA ) , best corrected visual acuity ( BCVA) , and wavefront aberration between the two groups were compared at 1, 3, 6mo and 1a after surgery.?RESULTS:At 1 and 3mo after surgery, the number of patients with better postoperative UCVA than preoperative BCVA between the two group showed a statistically significant difference (χ2=6. 423, P=0. 011,χ2=14. 431, P=0. 01 ); at 1d and 1mo after surgery, the residual astigmatism showed a statistically significant difference between two groups (t=1. 98, P 0. 05 ). At 6mo and 1a after surgery, the differences on UCVA between the two groups weren’t significant ( P > 0. 05 ). Until 1a after surgery, the root mean square ( RMS ) of high order wavefront aberration of the two groups, spherical aberration and coma aberration ( COMA ) were all enhanced compared to before surgery(P<0. 05). At 1, 3mo after surgery, the RMS showed a statistically significant difference between two groups (P<0. 05). At 1, 3, 6mo, 1a after surgery, the increase of COMA in experimental group was significantly lower than that in control group (P<0. 05).? CONCLUSION: Iris location technology applied in femtosecond - combined wavefront guided LASIK for myopia and astigmatism, can make the vision recovery faster, the RMS of high order and COMA increase less, the residual astigmatism less, show better and more stable treatment effect.
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?AlM:To compare the effect of iris location guided sub-bowman keratomileusis ( SBK ) and iris location guided thin - flap laser in situ keratomileusis ( LASlK ) for extremely high myopia treatment. ?METHODS:lris location guided SBK was performed in 64 eyes of 32 patients with extremely high myopia and 42 eyes of 84 patients were received iris location guided thin-flap LASlK. All the patients’ spherical refraction was-9. 00D ~ - 11. 00D and the age was 22 ~ 35 years. Uncorrected visual acuity ( UCVA) , refraction, split-lamp examination, topography examination, central corneal stroma thickness, thickness of central corneal flap, thickness of peripheral corneal flap and complication was examined in these patients and follow-up was 6mo. ?RESULTS:At 6mo after surgery, 93. 8% of the patients received iris location guided SBK and 92. 9% received iris location guided thin-flap LASlK achieved a UCVA better than 20/20. There was no significant difference between two groups. Refraction between ±0. 5D was 89. 1% of SBK group and 84. 5% of LASlK group. There was no significant difference. Corneal rear surface height of SBK was 0. 046±0. 012μm and LASlK was 0. 056±0. 015μm. Thickness of corneal stroma after surgery was 328. 6±14. 7μm in SBK group, while it was 301. 2±21. 6μm in LASlK group and there was significant difference ( t =3. 127, P=0. 001). BUT was 11. 38±4. 02s and 17. 81±4. 89s in SBK and LASlK group respectively, with no statistical difference. There was no serious complication in two groups.?CONCLUTlON:Both iris location guided SBK and thin-flap LASlK are effective for extremely high myopia, but SBK is safer and more predictive than thin-flap LASlK.
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AlM:To make a analysis of visual quality of iris location guided femtosecond laser assisted in situ keratomi ( LASlK) and iris location guided mechanical sub-bowman keratomileusis ( SBK) for high myopia treatment.METHODS:Femtosecond LASlK ( study group ) was performed in 102 eyes of 51 patients with high myopia and 70 eyes of 35 patients were received mechanical SBK ( control group ) from January to October 2013. The spherical refraction of all the patients was from -6. 00 ~-9. 50D. Best corrected visual acuity ( BCVA ) of the patients was ≥1. 0. Uncorrected visual acuity ( UCVA), BCVA, thickness of cornea flap, contrast sensitivity function ( CSF ) and senior ocular aberration were examined in these patients and follow-up was 1a.RESULTS: At 1a after surgery 94. 1% UCVA in study group reached ≥1. 0 and there was 94. 3% in control group. There was no significant difference between two groups (P>0. 05). Residual refraction of study group was-0. 08±0. 10 D and control group was -0. 10±0. 07 D. There was no significant difference of residual refraction between two groups (P>0. 05). C12 , C8 of senior ocular aberration and RMSH in study group was less than control group, amplification:0.1642±0.0519 and 0.2229±0.0382 (t=8. 077, P0. 05). C8 was 0. 0950±0. 069 and 0. 1858±0. 095 (t=7. 261, P0. 05). CONCLUSlON: Femtosecond LASlK and mechanical SBK is effective for high myopia. Compared to mechanical SBK, femtosecond LASlK shows more advantages in the senior ocular aberration and visual quality. The cornea flap is more regular from central to peripheral area with femtosecond laser.
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AIM: To discuss the single application on iris localization technology in excimer laser for the treatment of astigmatism. METHODS:Totally 203 cases (406 eyes) of laser in situ keratomileusis ( LASIK ) in the treatment of compound myopic astigmatism patients were operated from November 2011 to November 2012 in our hospital. They were divided into two groups. One was observation group using iris localization and the other was control group using routine operation. Patients in the observation group of 100 cases ( 200 eyes ) , aged 18-43 years old, spherical diopter was - 1. 25 to - 8. 75D, astigmatism was -1. 0 to -3. 25D. In control group, 103 patients ( 206 eyes ) , aged 19-44 years old, spherical diopter was -1. 75-9. 50D, astigmatism was -1. 0 to -3. 25D. The patients in the observation group before the application of WaveScan aberrometer check for iris image, spherical lens, cylindrical lens and astigmatism axis data operation, only single application of iris location, without using wavefront aberration guided technology, laser cutting patterns for conventional LASIK model, spherical, cylindrical mirror and astigmatism axis RESULTS: Postoperative residual astigmatism, the observation group was significantly better than the control group. Astigmatism axial measurement after operation, the observation group was significantly less than that of the control group. Postoperative visual acuity at 6mo, the observation group was better than that of the control group. The difference was statistically significant. data source to preoperative wavefront aberration results. The control group received routine LASIK. It was applicated comprehensive optometry optometry respectively to examine astigmatism and axial, based on the computer analysis during the preoperative, 1wk after the operation, and 6mo. Analysis of using SPSS 17 statistical software, it was independent-sample t test between the two groups of residual astigmatism and astigmatism axis. CONCLUSION: For patients who cannot complete the wavefront aberration guided treatment of astigmatism, can separate the application of wavefront aberration analyzer automatic iris recognition technology to improve precision of astigmatism treatment, give full play to advanced technical performance of equipment, which has good application value.