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According to our data, values for the flap thickness varied with the suction duration. There was a statistically significant difference among 3 groups (P=0.001). The flaps of group 1 (10 seconds) were statistically thinner than those of group 3 (30 seconds, P<0.01). Therefore, in order to minimize the risk of cutting an overly thick flap and maintain a residual stromal bed thicker, maintaining optimal suction duration is necessary, which depends on practiced, perfect and smooth operation.
A thinner corneal flap is of benefit in the prevention of keratectasia. Control of flap thickness can be useful in the other clinical aspects. Very flat corneas with average keratometric power of less than 41 diopters (D) are at a greater risk for cutting a free flap[16]. A smaller area of the cornea is usually exposed to the microkeratome blade in these cases, resulting in a free cap[17]. Sufficient suction duration that thickens the flap would increase the hinge area and decrease the probability of creating a free flap.
In conclusion, values for the flap thickness and flap diameter varied with the suction duration. We suggest corneal flap thickness should be routinely measured intraoperatively to ensure that enough tissue remain after surgery.
【参考文献】
1 Pallikaris IG, Papatzanaki ME, Stathi EZ, Frenschock O, Georgiadis A. Laser in situ keratomileusis. Laser Surg Med 1990;10(5):463468
2 Sugar A, Rapuano CJ, Culbertson WW, Huang D, Varley GA, Agapitos PJ, de Luise VP, Koch DD. Laser in situ keratomileusis for myopia and astigmatism: safety and efficacy: a report by the American Academy of Ophthalmology. Ophthalmology 2002;109(1):175187
3 Seiler T, Koufala K, Richter G. Iatrogenic keratectasia after laser in situ keratomileusis. J Refract Surg 1998;14(3):312317
4 Liu KY, Lam DS. Direct measurement of microkeratome gap width by electron microscopy. J Cataract Refract Surg 2001;27(6):924927
5 Choudhri SA, Feigenbaum SK, Pepose JS. Factors predictive of LASIK flap thickness with the Hansatome zero compression microkeratome. J Refract Surg 2005;21(3):253259
6 Flanagan GW, Binder PS. Precision of flap measurements for laser in situ keratomileusis in 4428 eyes. J Refract Surg 2003;19(2):113123
7 Flanagan GW, Binder PS. The theoretical vs. measured laser resection for laser in situ keratomileusis. J Refract Surg 2005;21(1):1827
8 Gailitis RP, Lagzdins M. Factors that affect corneal flap thickness with the Hansatome microkeratome. J Refract Surg 2002;18(4):439443
9 Kasetsuwan N, Pangilinan RT, Moreira LL, DiMartino DS, Shah SS, Schallhorn SC, McDonnell PJ. Real time intraocular pressure and lamellar corneal flap thickness in keratomileusis. Cornea 2001;20(1):4144
10 Módis L Jr., Langenbucher A, Behrens A, Seitz B. Flap quality in single versus multiple use of the same blade in the Flapmaker microkeratome. J Refract Surg 2004;20(3):258264
11 Spadea L, Cerrone L, Necozione S, Balestrazzi E. Flap measurements with the Hansatome microkeratome. J Refract Surg 2002;18(2):149154
12 Seo KY, Wan XH, Jang JW, Lee JB, Kim MJ, Kim EK. Effect of microkeratome suction duration on corneal flap thickness and incision angle. J Refract Surg 2002;18(6):715719
13 Tervo TM. Iatrogenic keratectasia after laser in situ keratomileusis. J Cataract Refract Surg 2001;27(4):490491
14 Roy AS, Dupps WJ Jr. Effects of altered corneal stiffness on native and postoperative LASIK corneal biomechanical behavior: A wholeeye finite element analysis. J Refract Surg 2009;25(10):875887
15 Wang A, Chen W, He R, Wang X, Liu C. Experimental study on corneal biomechanical properties of rabbit eye after LASIK. Shengwu Yixue Gongchengxue Zazhi 2009;26(2):323326
16 Sridhar MS, Rao SK, Vajpayee RB, Aasuri MK, Hannush S, Sinha R. Complications of laser in situ keratomileusis. Indian J Ophthalmol 2002;50(4):265282
17 Gimbel HV. Flap complications of lamellar refractive surgery. Am J Ophthalmol 1999;127(2):202204 上一页 [1] [2] |
