ABSTRACT
Keratoconus is an ophthalmopathy that has high morbidity and is likely to cause blindness. The currently available therapeutic options for keratoconus mainly include wearing rigid gas permeable (RGP) contact lenses, corneal cross linking, and keratoplasty, etc., which,however, require high treatment cost and long-term medicinal treatment with indefinite therapeutic effect. lntracorneal lens implantation has emerged as a new technique for the treatment of keratoconus, which attempts to implant a lens of certain power into the corneal interlayer, so as to allow the visual acuity to recover quickly while treating keratoconus. This paper reviews the advances and the development prospect of intracorneal lens implantation.
ABSTRACT
?Corneal collagen cross-linking ( CXL ) could increase the mechanical strength, biological stability and halt ectasia progression due to covalent bond formed by photochemical reaction between ultraviolet - A and emulsion of riboflavin between collagen fibers in corneal stroma. Corneal melting is an autoimmune related noninfectious corneal ulcer. The mechanism of corneal melting, major treatment, the basic fundamental of ultraviolet- A riboflavin induced CXL and the clinical researches status and experiment in CXL were summarized in the study.
ABSTRACT
AIM: To evaluate the changes of corneal high - order aberration (including Coma, Spab, RMSh) after laser in situ keratomileusis (LASIK) with femtosecond laser, sub- Bowman keratomileusis ( SBK ) and laser epithelial keratomileusis (LASEK). METHODS: Of 82 myopic patients ( 164 eyes ), 31 patients (62 eyes) were treated by FS-LASIK, 31 patients (62 eyes) were treated by SBK, 20 patients (40 eyes) were treated by LASEK. Sirius system was used for measuring the coma aberration, spherical aberration, and high order aberration at 1, 15d,1, 3mo after surgery. RESULTS: 1) Vision: The uncorrected visual acuity of the three groups had no differences (P>0. 05). 2) Corneal aberrations: Three kinds of surgical procedure for patients with corneal aberration had significant impact. The C7, C8, C12 and RMSh of three groups were increased significantly (P<0. 05). The C7, C8, C12 and RMSh were not recovered to preoperative levels after 3mo. But the increase of patients after FS- LASIK was smaller than the other two groups, with statistical significance (P<0. 05). CONCLUSION: Compared with SBK and LASEK, FS - LASIK has better visual acuity in the early postoperative and corneal higher-order aberrations increase is relatively small.
ABSTRACT
AIM: To evaluate the accuracy of central conreal thickness ( CCT ) using EX500 Excimer Laser workstation (EX500) in laser in situ keratomileusis (LASIK) patients.METHODS:The CCT of 120 eyes (63 patients) who had LASIK between January 2013 and June 2013 were measured by A- scan and EX500. Three groups were classified: >550μm, 500 ~550μm, RESULTS: The average preoperative CCT value was 527. 9±34. 3μm measured by A-scan, 528. 5±34. 6μm measured by EX500. There was no significant difference between these two measurements (t=1. 736, P=0. 085). In group which CCT >550μm, the average preoperative CCT value was 571. 4±17. 3μm measured by A-scan, 572.7±15. 7μm measured by EX500. There was no significant difference between these two measurements (t=1. 857, P=0. 072). In group which CCT 500 ~ 550μm, the average preoperative CCT value was 523. 4±13. 1μm measured by A-scan, 524. 2±12. 4μm measured by EX500. There was no significant difference between these two measurements ( t=1. 934, P = 0. 058 ). In group which CCT CONCLUSION: There is no significant difference between preoperative CCT value measured by A-scan and EX500. After corneal flap lifting and keratomileusis, the CCT value measured by EX500 is smaller than measured by A-scan.