Ablation of the cornea by using a low-energy excimer laser
- 38 Downloads
We describe a new multipurpose method for corneal refractive surgery by using a focused excimer laser beam, which allows the application of a small, compact low-energy excimer laser. It is possible to ablate any area desired in the cornea without masking by scanning the focused beam. The ablation depths in freshly enucleated swine eyes were measured in relation to the number of laser pulses (at fixed fluence) and the pulse fluence at wavelengths λ = 248 nm and λ =193 nm. The irradiation conditions were investigated to obtain smooth ablation of the corneal material over an area of about 1 cm2. The experiments show that smooth ablation is obtained when the ratio of the excimer laser beam spot diameter on the corneal surface and the displacement for one scanning step is given by a whole number. A simple model based on rectangular beam profiles is presented to exemplify this.
KeywordsLaser Pulse Irradiation Condition Excimer Laser Spot Diameter Beam Spot
Unable to display preview. Download preview PDF.
- 1.Aron-Rosa DS, Boulnoy JL, Carré F, Delacour J, Gross M, Lacour M, Olivo JC, Timsit JC (1986) Excimer laser surgery of the cornea: qualitative and quantitative aspects of photoablation according to the energy density. J Cataract Refract Surg 12:27–33Google Scholar
- 2.Dardenne MU, Hohla K (1989) Photoablation with the excimer laser — a new surgical tool. Medical focus ed. 1/89, special print of Technolas, GräfelflngGoogle Scholar
- 3.Fuxbruner A, Hemo I, Lewis A, Zauberman H, Blau D, Polotsky D (1990) Controlled lens formation with uapertured excimer lasers: use with organic polymers and corneal tissue. Appl Optics 29:5380–5385Google Scholar
- 4.Hanna KD, Pouliquen Y, Warning III GO, Savoldelli M, Cotter J, Morton K, Menasche M (1989) Corneal stromal wound healing in rabbits after 193 m excimer laser surface ablation. Arch Ophthalmol 107:895–901Google Scholar
- 5.Kitai MS, Popkov VL, Semchishen, Kharizov AA (1991) The physics of UV-laser cornea ablation. IEEE J Quant Electron 27:302–307Google Scholar
- 6.L'Esperance FA Jr, Warner JW, Telfair WB, Yoder PR, Martin CA (1989) Excimer laser instrumantation and technique for human corneal surgery. Arch Ophthalmol 107:131–139Google Scholar
- 7.Schröder E, Dardenne MU, Neuhann T, Tenner A (1987) An opthalmic excimer laser for corneal surgery. Am J Ophthalmol 103:472–473Google Scholar
- 8.Seiler T, Bende T, Wollensack J (1987) Astigmatismus-Korrektur mit dem Excimer Laser. Klin Monatsbl Augenheilkd 191:179–183Google Scholar
- 9.Seiler T, Kahle G, Kriegerowski M, Bende T (1990) Excimer laser (193 nm) myopic keratomileusis in sighted and blind human eyes. Refract Corneal Surg 6:165–173Google Scholar
- 10.Sowada U, Kahlert HJ, Basting D, Seiler T, Wollensack J (1987) A beam delivery system for excimer laser corneal refractive surgery. Medical Report Lambda, no. 1 Lambda Physik, GöttingenGoogle Scholar