Thin-Flap Laser in Situ Keratomileusis Associated Dry Eye

Assiut University

Status: Completed

Conditions: Myopic LASIK Candidates With Spherical Equivalent up to - 10 Diopters

Treatments: Procedure: Laser in situ keratomileusis

Study type: Interventional

Funder types: Other

Identifiers

NCT04831177

TFLADE

Details and patient eligibility

About

Laser in situ keratomileusis (LASIK) eye surgery continues to be the most common refractive procedure used to correct different forms of ametropia. Although the introduction of femtosecond technology has markedly reduced the incidence of intraoperative flap complications and allowed a better control on flap parameters, dry eye remains one of the most challenging postoperative complications.

Full description

The pathophysiology of post LASIK dry eye is not clear; however, many mechanisms have been suggested including inflammation, loss of conjunctival goblet cells during suction, exacerbation of a preexisting dry eye, abnormal interaction between the lid margins and the ocular surface. Intact corneal sensation is crucial for proper tear production and distribution on the ocular surface as well as maintaining the normal dynamics of eyelid blinking. Disruption of corneal nerves in LASIK decreases the release of neurotrophic factors necessary for the normal function of the corneal epithelium as well as the integrity of the lacrimal functional unit, a condition referred to as LASIK induced neurotrophic epitheliopathy (LINE) that largely contributes to the development of post- LASIK dry eye .

Many studies evaluated the incidence of post-refractive dry eye after LASIK compared to flapless laser vision correction (LVC) procedures such as PRK and small incision lenticule extraction (SMILE). The aim of this study is to assess and compare different dry eye parameters following LASIK with planned thin flaps created by femtosecond laser (FS) and mechanical microkeratome (MK).

Enrollment: 55 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Candidates for Laser Vision Correction (LVC).
2. Eyes with spherical equivalent (SE) up to - 10 diopters (D),
3. Corneal thickness at thinnest location of ≥ 500 um and estimated postoperative residual stromal bed of at least 300 um

Exclusion criteria

1. Patients with symptoms or signs of dry eye (TBUT <10 sec, Schirmer I test <10mm and Ocular Surface Disease Index OSDI score >13),
2. Posterior blepharitis, contact lens wearers ,
3. Ocular surface disease ,
4. Systemic diseases contraindicating LASIK and previous ocular surgery.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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55 participants in 2 patient groups

Patients planned to undergo Femtosecond laser FS assisted LASIK

Active Comparator group

Description:

In FS group, Allegretto WaveLight FS-200 femtosecond laser was used to create flaps with flap thickness planned to be 100 um.

Treatment:

Procedure: Laser in situ keratomileusis

Patients planned to undergo Microkeratome MK assisted LASIK

Active Comparator group

Description:

In MK group, Moria 2 Microkeratome was used to create flaps with flap thickness planned to be 100 um.

Treatment:

Procedure: Laser in situ keratomileusis