Evaluating the Effect of Optical Zones on Correction for SMILE: Vector Analysis

Tianjin Eye Hospital

Status: Completed

Conditions: Myopia

Treatments: Procedure: small incision lenticular extraction

Study type: Observational

Funder types: Other

Identifiers

NCT05017376

TJYYLL-202034

Details and patient eligibility

About

Evaluate the effect of the size of optical zones (OZ) on myopia and astigmatism correction in small incision lenticular extraction.

Full description

To retrospectively study whether different surgical optical zone sizes affect the correction of diopter and astigmatism in myopia patients. Divided into 2 groups according to the diameter of the optical zone. The vector analysis method was used to analyze the changes and errors of astigmatism in TR and SIR after operation. Generalized Estimation Equation (GEE) model is used for multiple regression analysis to evaluate the potential factors related to the error value.

Enrollment: 140 patients

Sex: All

Ages: 18 to 45 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• no ocular conditions
• normal topography
• central corneal thickness, >500µm
• residual stromal thickness, >280 µm
• pupil diameter, 2.78-4.9 mm (average, 3.76±0.43 mm);

Exclusion criteria

• history of intraocular surgery
• pupil diameter, >4.9 mm or <2.78mm
• keratoconus or corneal ectasia

Trial design

140 participants in 2 patient groups

group A

Description:

small optical zone

Treatment:

Procedure: small incision lenticular extraction

group B

Description:

large optical zone

Treatment:

Procedure: small incision lenticular extraction