Clinical trial NCT02550353: Changes Between Lenticule Extraction and Femtosecond Laser-assisted Laser in Situ Keratomileusis
Official title: Comparison of Early Changes in Ocular Surface and Inflammatory Mediators Between Lenticule Extraction and Femtosecond Laser-assisted Laser in Situ Keratomileusis
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Myopia
Astigmatism
Keywords: lenticule extraction
femtosecond laser-assisted laser in situ keratomileusis
tear
inflammatory mediators
Lead sponsor: Sun Yat-sen University
Sponsor class: OTHER
First posted: 2015-09-15
Enrollment: 75
Sex: ALL
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The aim is to evaluate the short-term changes in ocular surface measures and tear inflammatory mediators after lenticule extraction (FLEx) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) procedures.

Detailed description: Over the past few years, laser in situ keratomileusis with a femtosecond laser-created flap (FS-LASIK)has been a popular ophthalmic procedure for the correction of refractive error. This first all-in-one FS-laser system was designed to perform the refractive lenticule extraction (ReLEx) procedures, femtosecond lenticule extraction (FLEx).They have the same feature: corneal flap.

Ocular surface disruption during corneal refractive surgery is commonly considered to be closely related to the development of dry eye. Multiple etiologies contribute to this ocular surface disruption, including the flap creation and stromal ablation involved in previous refractive surgery techniques. Corneal nerve damage has been considered the main cause of dry eye, due to disrupted afferent sensory nerves, reduced blink reflex, and increased tear evaporation leading to tear film instability. In addition, postoperative inflammatory mediator fluctuations are also a key factor related to ocular surface damage. Extensive research has described the effects of cytokines, chemokines and growth factors in modulating corneal wound healing, cell migration, and apoptosis on the ocular surface after refractive surgery.

This prospective clinical study is going to assess the short-term changes in ocular surface measures and tear inflammatory mediators after lenticule extraction (FLEx) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) procedures.

Eligibility criteria: Inclusion Criteria:

* minimum age of 18 years(range from 18 year to 25 years)
* corneal thickness 500 μm with calculated residual stromal bed after treatment greater than 300 μm
* preoperative spherical equivalent refraction between- 2.00 diopter (D) and -6.50 D.preoperative cylindrical equivalent refraction between -0.25 D and -1.50 D.
* preoperative corneal curvature from 41.0 D to 46.0 D with a regular topographic pattern monocular best corrected visual acuity of 20/20 or better and stable refractive error (less than 0.5 D change) for 24 months before surgery。

Exclusion Criteria:

* systemic disease that contraindicated the surgery (such as diabetes, glaucoma and systemic collagen vascular disease)
* corneal abnormality or disease.
* a history of tear supplement usage or contact lens wear during the past year.

Primary outcomes:
measure: Schirmer I test
timeFrame: up to 1month after surgery
measure: corneal fluorescein staining
timeFrame: up to 1month after surgery
measure: noninvasive tear breakup time
timeFrame: up to 1month after surgery
measure: ocular surface disease index
timeFrame: up to 1month after surgery
measure: central corneal sensitivity
timeFrame: up to 1month after surgery
measure: tear meniscus height
timeFrame: up to 1month after surgery
measure: Interleukin-1α
timeFrame: up to 1month after surgery
measure: tumor necrosis factor-α
timeFrame: up to 1month after surgery
measure: nerve growth factor
timeFrame: up to 1month after surgery
measure: interferon-γ
timeFrame: up to 1month after surgery
measure: transforming growth factor-β1
timeFrame: up to 1month after surgery
measure: matrix metalloproteinase-9
timeFrame: up to 1month after surgery
Secondary outcomes:
measure: Correlation Between Inflammatory Mediators and Ocular Surface Changes
timeFrame: up to 1month after surgery
Other outcomes:
Locations:
city: Haikou
country: China
facility: Hainan Eye Hospital, Zhongshan Ophthalmic Center of Sun Yat-sen University
state: Hainan
Study officials:
affiliation: Hainan Eye Hospital, Zhongshan Ophthalmic Center of Sun Yat-sen University
name: Xingwu Zhong, MD,PhD
role: PRINCIPAL_INVESTIGATOR
References: