Z8 OCT-controlled 2D vs 3D LASIK

Hamburg Vision Center

Status: Completed

Conditions: Myopia; Astigmatism

Treatments: Device: 2D and 3D cutting method using a low energy Femtosecond laser LDV Z8 for LASIK flap cutting

Study type: Interventional

Funder types: Industry

Identifiers

NCT04426175

CPFEM-0007-DE

Details and patient eligibility

About

The aim of this study was to test the hypothesis that OCT-guided 110 µm targeted flaps will result in accurate, predictable, and precise thickness flaps, with low complication rates when performed and compared using both 2D and 3D flap geometry applications and how it correlated to visual experience and quality of life responses during the early postoperative period.

Full description

It has been postulated that it is possible with the Ziemer Femtosecond LDV laser system to create reproducible flaps in terms of thickness and predictability. The aim of this study was to test the hypothesis that OCT-guided 110 µm targeted flaps will result in accurate, predictable, and precise thickness flaps, with low complication rates when performed and compared using both 2D and 3D flap geometry applications. Patient-reported outcomes are increasingly incorporated into clinical trials as they provide access to valuable information on the physical experience of the patient during and after the treatment. A questionnaire will therefore also be introduced in this study to evaluate how well self-reported pain, visual experience, and quality of life responses are correlated with flap geometries in both groups during the early postoperative period. The study holds direct medical benefit to the patient in this that they received an immediate improvement in his/her unaided vision. Moreover, the patient's participation contributes to the medical knowledge about the use of femtosecond lasers for refractive surgery, in particular in view of the use of intraoperative OCT visualization tools. The patients will gain access to the newest technology available for refractive surgery namely a low pulse energy high-frequency femtosecond laser.

Enrollment: 13 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

Key inclusion criteria as described by the German Commission for Refractive Surgery (KRC) are:

• The recommended range of application for the correction of myopia is up to -8.00 D and for the correction of astigmatism up to 5.00 D.
• The limited for LASIK correction of myopia is up to -10.00 D and correction of astigmatism up to 6.00 D. If myopic astigmatism is to be corrected, the values for myopia and astigmatism must be added together.
• The recommended range for correction of hyperopia is up to 3.00 D. Up to 4.00 D is the range of limited application for hyperopia.
• Age ≥18 years with stable eyesight for over 12 months.

Exclusion criteria

Key exclusion criteria as described by the German Commission for Refractive Surgery (KRC):

• preoperative corneal thickness less than 480 μm
• predicted stromal thickness under the flap after ablation of less than 250 μm
• chronic progressive corneal disease and forme fruste keratoconus
• surgery before the age of 18 years
• symptomatic cataract
• Glaucoma with a marked loss of visual field
• Exudative macular degeneration.
• Concurrent participation in another ophthalmological clinical study

Exclusion criteria irrespective of the KRC criteria:

• Undergone former eye surgery
• Contact lens wear within the two weeks prior to commencement of preoperative measurements

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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13 participants in 2 patient groups

2D LASIK

Experimental group

Description:

With the 2D method, the flap resection is created in a planar mode (xy-plane), without vertical cut, at the requested depth.

Treatment:

Device: 2D and 3D cutting method using a low energy Femtosecond laser LDV Z8 for LASIK flap cutting

3D LASIK

Experimental group

Description:

With the 3D method, the flap resection is done in a three-dimensional mode, at the requested depth, with the requested diameter and the desired border (side cut) angle

Treatment:

Device: 2D and 3D cutting method using a low energy Femtosecond laser LDV Z8 for LASIK flap cutting