Important Information; Description; Indications; Head Calibration Value And Flap Thickness - MORIA 65005 Manuel Utilisateur

5 IMPORTANT INFORMATION

5.1 DESCRIPTION

The CB microkeratome is a manual, mechanical, pivoting microkeratome. It has three components:
• a pneumatic turbine
• a manual metallic suction ring
• a single use plastic head (CBSU) encasing a pre-inserted blade, or a metallic reusable head (CB,
CBm).
The CB microkeratome operates with the EVOLUTION 2, 3, and 3E control units. Please refer to the user
guides.

5.2 INDICATIONS

The CB microkeratome is indicated for the creation of lamellar corneal flaps on patients' eyes when using CB,
CBm, or CBSU heads in combination with a manual suction ring in corneas with preoperative pachymetry of
500 microns or greater, and keratometry between 39 D and 48 D.
During laser in-situ keratomileusis (LASIK), the flap is then lifted to enable photoablation of the stroma with
an excimer laser.

5.3 HEAD CALIBRATION VALUE AND FLAP THICKNESS

Flap thickness is a key factor for LASIK surgery. Multiple parameters affect flap thickness and standard
deviation. Numerous scientific studies have demonstrated that flap thickness is influenced by several patient-
related factors such as keratometry (K) readings, corneal anatomy, preoperative pachymetry and refraction,
intraocular pressure (IOP), and also by surgery-related factors, such as corneal hydration and the speed of
the pass (when using manual microkeratomes).
Ultrasonic pachymetry measurements are not always accurate and reproducible, and results may also vary
with surgeons' techniques and calibration of the device. Thus, a head labeled «130» cuts on average a
160-micron flap:
• 130 microns is a dimension on the head that can be measured and which corresponds to a distance
from the cutting edge of the blade to the front plate of the head
• 160 microns is the average flap thickness that will be cut by this head, with variations around this
average value.
In the example above, the "incremental value" for a 130 head is 30 microns on average.
Head calibration value
130
MORIA can only guarantee the dimensional characteristics of the head, not the surgical result.
The surgeon is strongly advised to carry out tests beforehand to determine the thickness and diameters of
the expected cuts based on his/her own technique.

5.4 CONTRAINDICATIONS

Patients who are not candidates for LASIK.
Note: Careful preoperative evaluation and sound clinical judgment should be used by the surgeon to
determine the risk/benefit ratio. Particular attention must be given before performing a keratectomy on a
patient with any of the following conditions:
• preoperative pachymetry under 500 microns
• keratometry under 39 D
• keratometry over 48 D
• inability to withstand a transient rise in intraocular pressure.
Incremental value
+30
Average flap thickness
160
#65005-F-02.2017 MORIA
5