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

Tianjin Eye Hospital140 enrolled

Overview

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

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.

Study Type

OBSERVATIONAL

Enrollment

140

Conditions

Myopia

Interventions

small incision lenticular extractionPROCEDURE

In patients with the same degree of myopia, different optical zones were designed for operation

Eligibility

Sex: ALLMin age: 18 YearsMax age: 45 Years

Medical Language ↔ Plain English

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

Locations (1)

Tianjin Eye Hospital

Tianjin, China

Outcomes

Primary Outcomes

astigmatic changes

Observe the effect on changes in astigmatism by target induced astigmatism (TIA) versus surgically induced astigmatism (SIA)

Time frame: 2021.03

error value

Target refraction (TR) and surgically induced refraction (SIR) under different optical zones

Time frame: 2021.04

Data from ClinicalTrials.gov

This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.