Skip to main content
OpenTrials
Completed

NCT Number: NCT06898164

The Influence of Axial Length on Visual Quality Following SMILE Surgery in Patients with High Myopia

This retrospective study aimed to investigate the subjective and objective visual outcomes following Small Incision Lenticule Extraction (SMILE) surgery in high myopic patients with varying axial lengths (AL).

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Visual Quality Axial Length High Myopia

Age range

18 year–40 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Shanghai Tenth People's Hospital

Shanghai, Shanghai Municipality, 200000, China

About this study

The study enrolled 113 highly myopic patients (202 eyes) who underwent SMILE surgery at Shanghai's Tenth People's Hospital. Patients were classified into three groups based on the axial length before surgery: Group A (AL < 26 mm, 62 eyes), Group B (26 mm ≤ AL < 27 mm, 88 eyes), and Group C (AL ≥ 27 mm, 52 eyes). Preoperative and postoperative evaluations included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), equivalent spherical error(SE), and corneal high order aberration. Subjective visual quality was assessed using the Quality of Vision (QoV) questionnaire.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • manifest refraction spherical equivalent refraction exceeding -6.00D;
  • stable myopia for a duration of at least 2 years;
  • corrected distance visual acuity of at least 20/25;
  • annual myopic spherical equivalent increment less than - 0.50 D.

Exclusion criteria

  • a history of moderate to severe dry eye as well as any ocular or systemic disease.

Treatment and study plan

This study does not involve any interventions

Other

This study does not involve any interventions

Primary outcomes

  1. Subjective visual quality

    Time frame: 12 months

    The quality of vision (QOV) questionnaire consists of (i) symptom frequency, (ii) severity, and (iii) bothersomeness for (a) glare, (b) halo, (c) starbursts, (d) hazy vision, (e) blurred vision, (f) distortion, (g) multiple images, (h) visual fluctuations, (i) difficulty focusing, and (j) difficulty judging distance or depth perception. Respondents use a scale of 0 to 3, where zero (0) denotes "none," one (1) "a little," two (2) "quite a bit," and three (3) "very much." Furthermore, on a scale from 0 to 10, patients were asked to provide Likert ratings for "daytime" and "nighttime" quality of vision (0 denoting the poorest vision, while 10 indicating the best vision)

Secondary outcomes

  1. Refractive results

    Time frame: 12 months

    The uncorrected distance visual acuity (UDVA, logMAR), corrected distance visual acuity (CDVA, logMAR), subjective refraction (Diopter), and intraocular pressure (mmHg) were evaluated prior to and 1 year after SMILE.

Other outcomes

  1. Ocular high-order aberrations

    Time frame: 12 months

    Corneal aberration measurements were performed using a Scheimpflug tomography system (Pentacam; Oculus GmbH, Wetzlar, Germany). Images of the highest quality (designated as OK) were selected for analysis. The coefficients for a standardized diameter of 8 mm were examined, followed by an assessment of the clinical significance of total higher-order aberrations (HOA, mm), spherical aberration (Z4, 0, mm), horizontal coma (Z3, 1, mm), vertical coma (Z3, -1, mm), horizontal trefoil (Z3, 3, mm), and oblique trefoil (Z3, -3, mm)

Sponsors and collaborators

Lead sponsor

yuhao shao

Other

Collaborators

  • Shanghai 10th People's Hospital

Registry information

Important dates

Study start
2021
Primary completion
2024
Study completion
2024
First posted
Mar 27, 2025
Registry last updated
Mar 27, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.