Rescue of Primary Incomplete Microkeratome Flap with Secondary Femtosecond Laser Flap in LASIK

Razgulyaeva Ea

doi:10.1155/2014/289354

Abstract

For laser-assisted in situ keratomileusis (LASIK) retreatments with a previous unsuccessful mechanical microkeratome-assisted surgery, some surgical protocols have been described as feasible, such as relifting of the flap or the creation of a new flap and even the change to a surface ablation procedure (photorefractive keratectomy (PRK)). This case shows the use of femtosecond technology for the creation of a secondary flap to perform LASIK in a cornea with a primary incomplete flap obtained with a mechanical microkeratome. As we were unable to characterize the interface of the first partial lamellar cut, a thick flap was planned and created using a femtosecond laser platform. As the primary cut was very thick in the nasal quadrant, a piece of loose corneal tissue appeared during flap lifting which was fitted in its position and not removed. Despite this condition and considering the regularity of the new femtosecond laser cut, the treatment was uneventful. This case report shows the relevance of a detailed corneal analysis with an advanced imaging technique before performing a secondary flap in a cornea with a primary incomplete flap. The femtosecond laser technology seems to be an excellent tool to manage such cases successfully.

Highlights

Femtosecond laser technology has supposed a great advance for flap creation in laser-assisted in situ keratomileusis (LASIK) surgery and has demonstrated advantages over conventional mechanical microkeratomes [1, 2]
If the primary flap has been uneventfully done and relifting with manual dissection is not possible because of its strong adhesion, the creation of a new vertical side cut with the use of the femtosecond laser creates a net interface that diminishes the mechanical trauma to the epithelium (Guell et al [8]) and prevents epithelial ingrowth due to the vertical side cut configuration of the femtosecond flap compared to the sloping edge of the mechanical-based flap [9]
Vaddavalli et al found that femtosecond retreatment using a side cutonly algorithm is effective in the treatment of residual errors after mechanical microkeratome-based LASIK, reducing the rates of epithelial ingrowth [10]

Summary

Introduction

Femtosecond laser technology has supposed a great advance for flap creation in LASIK surgery and has demonstrated advantages over conventional mechanical microkeratomes [1, 2]. LASIK procedures performed with mechanical microkeratomes have been widely used for years and some patients may need a secondary laser treatment as a consequence of an over- or undercorrection, or regression [6] In such cases refractive surgeons may perform a photorefractive keratectomy (PRK) retreatment, and a LASIK retreatment with relifting of the original flap or the creation of a new flap in a deeper plane [7]. A comprehensive preretreatment analysis of the cornea by means of an imaging technique is necessary to avoid a flap cut interfering with the original cut, especially if this cut is irregular or incomplete due to intraoperative complications This case report shows the relevance of this detailed corneal analysis in a case of a secondary femtolaser flap in a cornea with a primary incomplete microkeratome flap

Case Report

Discussion