Ultrasound evaluation of flap thickness, ablation depth, and corneal edema after laser in situ keratomileusis

Zoltán Z. Nagy, Miklós Resch, I. Süveges

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Abstract

PURPOSE: The aim of our study was to evaluate the predictability of flap thickness and changes in flap edema over time after laser in situ keratomileusis (LASIK). METHODS: LASIK was carried out in 30 eyes. The corneal flap was created with a Moria CB manual microkeratome with a flap thickness of 130 μm. Photoablation was performed with the Zeiss-Meditec MEL 70 G-Scan flying spot excimer laser. Ultrasound pachymetric measurements were performed with the Humphrey Model 855 pachymeter. RESULTS: Preoperative mean corneal thickness was 568.43 ± 34.6 μm. After LASIK, mean flap thickness was 133 ± 26.4 μm. After excimer laser treatment, mean central corneal thickness decreased to a mean 392.4 ± 37.4 μm. Five minutes after repositioning the flap, mean central corneal thickness was 572.1 ± 43.4 μm. On the first postoperative day, it decreased to a mean 501.6 ± 46.6 μm followed by additional decreases: mean 487.4 μm on day 5, 481.8 μm after 1 month, and 479.6 μm at 6 months. The actual photoablation depth was 10 μm less than the predicted depth (paired sample t-test, no statistically significant difference, P=.018). A significant linear correlation was found (Pearson, R=.725, P=.001) between predicted and measured photoablation depth. CONCLUSIONS: Corneal flap thickness had greater variability than expected. After flap creation, stromal and flap edema occurred, but decreased during the first five postoperative days and stabilized thereafter.

Original languageEnglish
Pages (from-to)279-281
Number of pages3
JournalJournal of Refractive Surgery
Volume20
Issue number3
Publication statusPublished - Apr 2004

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Corneal Edema
Laser In Situ Keratomileusis
Excimer Lasers
Edema
Therapeutics

ASJC Scopus subject areas

  • Ophthalmology

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Ultrasound evaluation of flap thickness, ablation depth, and corneal edema after laser in situ keratomileusis. / Nagy, Zoltán Z.; Resch, Miklós; Süveges, I.

In: Journal of Refractive Surgery, Vol. 20, No. 3, 04.2004, p. 279-281.

Research output: Contribution to journalArticle

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