Abstract
• Background: Excimer laser trephination, as an alternative to mechanical trephination of the cornea in penetrating keratoplasty, is expected to reduce long-term postkeratoplasty astigmatism. Trephination with high energy densities may induce thermal epithelial alterations when metal aperture masks are used. • Methods: Ninety porcine eyes fixed in an artificial anterior chamber (20 mmHg) were trephined with a 193-nm excimer laser in order to study the effect of the temperature on the cornea and the aperture mask during and after termination of the laser exposure. Energy levels tested were in the range used in patients. A pyroelectric infrared sensor connected to a PC via an analog-digital converter was used. With a high-speed sampling routine written inC++ it was possible to monitor on line the temperature in a focus 0.8 mm in diameter. • Results: In donor trephination the maximum temperature increase of the metal mask was 11 K (donor tissue 6.1 K, repetition rate 30/s). During recipient trephination the maximum temperature increase of the mask was 9.4 K (7.5 K on the cornea). An increase in the repetition rate and a decrease in the rotation speed resulted in greater temperature increase of the exposed cornea or metal mask. • Conclusions: Online monitoring of cornea and mask surface temperatures during excimer laser trephination is possible using high-speed sampling equipment. Appropriate adjustment of repetition rate and rotation speed may reduce thermal effects, especially in donor trephination.
Similar content being viewed by others
References
Bende T, Seiler T, Wollensak J (1988) Side effects in excimer corneal surgery — corneal thermal gradients. Graefe's Arch Clin Exp Ophthalmol 226:277–280
Gebhardt E, Lang GK, Tittelbach H, Rau D, Naumann GOH (1990) Untersuchungen zur Chromosomenmutagenität eines 193 nm Excimer Lasers. Fortschr Ophthalmol 87:229–233
Koch JW, Lang GK, Naumann GOH (1991) Endothelial reactions to perforating and non-perforating excimer laser excisions in rabbits. Refract Corneal Surg 7:214–222
Krüger R, Trokel S, Schubert H (1985) Interaction of ultraviolet laser light with the cornea. Invest Ophthalmol Vis Sci 26:1455–1464
Kubota T, Seitz B, Tetsumoto K, Naumann GOH (1992) Lamellar excimer laser keratoplasty: reproducible photoablation of corneal tissue — a laboratory study. Doc Ophthalmol 82:193–200
Kubota T, Seitz B, Tetsumoto K, Naumann GOH (1994) Lamellar keratoplasty with the excimer laser laser — a laboratory study. Jpn J Ophthalmic Surg 7:131–134
Lang GK, Schröder E, Koch JW, Yanoff M, Naumann GOH (1989) Excimer laser keratoplasty. I. Basic concepts. Ophthalmic Surg 20:262–267
Lang GK, Schröder E, Koch JW, Yanoff M, Naumann GOH (1989) Korneale Schnittkonfigurationen mit dem Excimer Laser. Fortschr Ophthalmol 86:437–442
Langenbucher A, Seitz B, Kus MM, Naumann GOH (1994) Graft decentration in penetrating keratoplasty — excimer laser trephination versus mo tor trephine. Invest Ophthalmol Vis Sci [Suppl] 35:1879
Lewis M, Dubin M, Aandahl V (1967) The physical properties of bovine corneal collagen. Exp Eye Res 6:57–69
Naumann GOH, Sautter H (1988) Surgical procedures of the cornea. In: Blodi FC, Mackensen G, Neubauer H (eds) Surgical ophthalmology I. Springer, Berlin Heidelberg New York, pp 491–566
Naumann GOH, Seitz B (1992) Excimer laser 193 nm trephination with “orientation teeth” in penetrating keratoplasty. Ophthalmology [Suppl] 99:122
Naumann GOH, Seitz B, Lang GK, Langenbucher A, Kus MM (1993) Excimer-Laser-193 nm-Trepanation bei der perforierenden Keratoplastik — Bericht über die ersten 70 Patienten. Klin Monatsbl Augenheilkd 203:252–261
Oraevsky AA, Esenaliev RO, Letokhov VS (1991) Pulsed laser ablation of biological tissue: review of the mechanism. Lect Notes Phys 389:112–122
Seiler T, Wollensak J (1986) In vivo experiments with the excimer laser - technical parameters and healing processes. Ophthalmologica 192:65–70
Seitz B, Grethlein S, Naumann GOH, Lang GK (1991) Elliptical penetrating keratoplasty (PK) with the excimer laser 193 nm-Thermal profile on metal mask and corneal tissue. Invest Ophthalmol Vis Sci [Suppl] 32:996
Seitz B, Langenbucher A, Kus MM, Naumann GOH (1993) Excimer laser 193 nm trephination with divergent cut angles in penetrating keratoplasty. Invest Ophthalmol Vis Sci [Suppl] 34:1285
Seitz B, Langenbucher A, Kus MM, Naumann GOH (1994) Consideration of donor and recipient corneal topography improves graft alignment in penetrating keratoplasty. Invest Ophthalmol Vis Sci [Suppl] 35:1879
Serdarevic ON, Khalil H, Gribomont AC, Savoldelli M, Renard G, Pouliquen Y (1988) Excimer laser trephination in penetrating keratoplasty. Ophthalmology 95:493–505
Shannon MA, Rostami AA, Russo RE (1991) Monitoring laser heating of materials with photothermal-deflection techniques. Lect Notes Phys 389:320–327
Sliney D (1985) Laser tissue interactions. Clin Chest Med 6:203–208
Tetsumoto K, Kazusa R, Seitz B, Naumann GOH (1992) Lamellar excimer laser keratoplasty: experimental study on photoablation depth. J Eye (Atarahii Ganka) 82:193–200
Trokel S, Srinivasan R, Braren B (1983) Excimer laser surgery of the cornea. Am J Ophthalmol 96:710–715
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Langenbucher, A., Seitz, B., Kus, M.M. et al. Thermal effects in excimer laser trephination of the cornea. Graefe's Arch Clin Exp Ophthalmol 234 (Suppl 1), S142–S148 (1996). https://doi.org/10.1007/BF02343064
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02343064