ABSTRACT
AIM: To observe the effect and safety of applying mitomycin C ( MMC ) in laser - assisted subepithelial keratomileusis ( LASEK) for extreme high myopia. ●METHODS:LASEK with 0. 02% MMC was performed in 364 eyes of 182 patients with extreme high myopia and spherical equivalent was-9. 0 to-10. 25 D. All the patients were divided into four groups according to the applying time of MMC. The time in Group l was 10s, in GroupⅡwas 25s, in Group Ⅲ was 40s and 55s in Group lV. Uncorrected visual acuity ( UCVA ) , residual refraction, Haze, healing time of corneal epithelium, density and variant index of corneal endothelium was examined in these patients and follow-up 6mo. ●RESULTS:At 6mo after surgery, 76. 3%, 94. 0%, 92. 3%and 93. 8% of the patients in Group l, GroupⅡ, GroupⅢ and Group lV respectively achieved the UCVA better than 15/20. There was significant difference of UCVA between Group l and the other three groups (χ2=19. 610, P=0. 000). Proportion of the residual refraction between ± 0. 5D in Group l (78. 8%) was lower than other groups (95. 2% in Group Ⅱ, 93. 3% in Group Ⅲ, and 92. 7% in GroupⅣ) at 6mo and there was significant difference (χ2=16. 329, P=0. 001). Group l had more Haze statistically than the other three groups at 6mo postoperatively ( Hc=50. 110, P=0. 000). The healing time of cornea epithelium seem to be no statistically difference between each group at 6mo (χ2=11. 611, P>0. 05). MMC had no influence on the density of corneal endothelium in each group postoperatively (P>0. 05), there were 3071. 3±284. 4 cells/mm2 in Group l, 3 105. 6 ± 337. 8 cells/mm2 in Group Ⅱ, 2 986. 3 ± 304. 1cells/mm2 in Group Ⅲ and 3 088. 7 ± 372. 5 cells/mm2 in Group lV respectively. The variant index of corneal endothelium calculated in each group at 6mo after surgery was 24. 72 ± 6. 52, 22. 93 ± 6. 74, 24. 38 ± 6. 63 and 23. 14±7. 22 repectively, compare with that preoperatively there were no statistically differences (P>0. 05). ●CONCLUSION: For extreme high myopia LASEK with 0. 02% MMC is effective and safe. The MMC applying time of 25s in LASEK can effectively reduce Haze after surgery and decrease potential complications.
ABSTRACT
Background In recent years,with the contiunous progress of the refractive surgery,the operation skill of phakic intraocular lens(PIOL)implantation for correcting extreme high myopia,astigmatism,farsightedness have made greater progression,and its security,effectiveness in clinical attract much more attention. Objective This study was to evaluate the efficacy,safety and stability of Toric Implantable Collamer Lens(TICL)for extreme high myopic astigmatism. Methods This retrospective case series included 33 eyes of 27 patients from May 2008 to February 2009.A TICL was intraocularly implanted via a 3 mm clear corneal incision after paraocular anesthesia.Patients were examined preoperatively and followed-up at 1 day,1 week,1 month,3,6,12 and 18 months postoperatively.The examinations included uncorrected visual acuity,best corrected visual acuity(BCVA),slit lamp examination,refraction,intraocular pressure,endothelial cell morphometry,etc.The written informed consent was obtained from each patient before any medical procedure. Results The uncorrected visual acuity in 96.97% eyes was equal or improved after operation in comparison with BCVA of preoperation.The spherical refraction was within-1.00 D-+0.25 D.The cylinder refraction was within-1.00 D-0 D.The axial deviation of TICL within 10 degree was 93.94%(31/33).No significant differences were found in the intraocular pressure and endothelial cell morphometry between preoperation and postoperation(intraocular pressure:F=3.35,P=5.49;endothelial cell morphometry:t=1.835,P=0.082).The visual acuity and refraction were stable during the follow-up.Astigmatic axial rotation required surgical intervention on one eye.One eye occurred high intraocular pressure because of bigger TICL diameter.The intraocular pressure returned to normal after TICL was exchanged.No cataract occurred during the follow-up duration. Conclusion TICL implantation appears to be an effective,safe and reliable method for extreme high myopic astigmatism.