Long-term Outcomes of SMILE PRO for High Astigmatism

Hanoi Medical University

Status: Active, not recruiting

Conditions: High Astigmatism

Treatments: Procedure: SMILE PRO surgery

Study type: Interventional

Funder types: Other

Identifiers

NCT07446751

#HMUIRB1649#

Details and patient eligibility

About

This prospective interventional study aims to evaluate the long-term refractive and visual quality outcomes of SMILE PRO surgery in patients with myopia and high astigmatism. Eligible participants undergo small incision lenticule extraction using the VisuMax 800 femtosecond laser. Postoperative assessments include uncorrected and corrected distance visual acuity, manifest refraction, astigmatic vector analysis, contrast sensitivity, and higher-order aberrations. Participants are followed for up to 12 months to assess refractive accuracy, stability, safety, and visual quality after surgery.

Full description

This is a single-center, prospective interventional clinical study conducted to assess the long-term refractive and visual quality outcomes of SMILE PRO surgery for the correction of myopia with high astigmatism. The study is performed at Hong Son Eye Hospital, Vietnam, following approval from the Institutional Review Board of Hanoi Medical University. All participants provide written informed consent prior to enrollment.

Patients aged 18 to 40 years with stable myopic refractive error and high astigmatism are eligible for inclusion. All eyes undergo small incision lenticule extraction using the VisuMax 800 femtosecond laser according to a standardized surgical protocol. Manifest refraction, corneal topography, and ocular imaging are performed by experienced refractive technicians using standardized measurement protocols. All patients are examined preoperatively and postoperatively by an ophthalmologist, who reviews clinical findings and surgical eligibility. All SMILE PRO procedures are performed by the same ophthalmic surgeon to minimize variability related to surgical technique.

Outcome measures include uncorrected and corrected distance visual acuity, spherical equivalent refraction, residual refractive astigmatism, and astigmatic vector analysis based on the Alpins method. Visual quality outcomes are further evaluated using contrast sensitivity testing and wavefront aberrometry to assess higher-order aberrations. Intraoperative parameters, including centration and cyclotorsion, are recorded and analyzed for their potential association with postoperative refractive outcomes.

Postoperative examinations are performed at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery. The primary objective of this study is to evaluate the long-term refractive accuracy, stability, and safety of SMILE PRO surgery in eyes with high astigmatism. Secondary objectives include the assessment of preoperative and intraoperative factors influencing postoperative visual and refractive outcomes.

Enrollment: 113 estimated patients

Sex: All

Ages: 18 to 40 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients aged 18 to 40 years at the time of surgery
• Diagnosis of myopia with high astigmatism eligible for SMILE PRO surgery
• Stable refractive error prior to surgery
• Adequate corneal thickness and topographic parameters suitable for SMILE PRO
• Ability to understand the study procedures and provide written informed consent
• Willingness and ability to attend scheduled postoperative follow-up visits

Exclusion criteria

• Presence of corneal ectatic disorders or suspicious corneal topography
• History of previous ocular surgery or ocular trauma
• Active ocular disease other than refractive error
• Systemic diseases known to affect wound healing
• Pregnancy or breastfeeding at the time of surgery

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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113 participants in 1 patient group

SMILE PRO surgery

Experimental group

Description:

Participants with myopia and high astigmatism undergoing small incision lenticule extraction using the SMILE PRO surgery.

Treatment:

Procedure: SMILE PRO surgery