Centration in refractive surgery

Comparison of asymmetric offset versus pupil centered ablation in refractive surgery

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

IRCT

Registry ID

IRCT20180428039441N2

Enrollment

Registered

2023-01-17

Start date

2023-02-09

Completion date

Unknown

Last updated

2023-02-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Centration of ablation profile in refractive surgery.

Interventions

Intervention 1: Intervention group: After local anesthesia, a flap (110 µm thick) is created using a Femto LDV (Ziemer Ophthalmic Systems AG, Port, Switzerland). After flap removal, ablation is perfor

Eligibility

Sex/Gender

All

Age

18 Years to 60 Years

Inclusion criteria

Inclusion criteria: Femto-LASIK candidates in following criteria Age: 18-60 years Spherical Equivalent (SE): +400 to -6.00 Diopter Corrected distance visual acuity (CDVA): 9/10 or better HOA (higher order aberration) < 0.65 µm Pupil offset = 0.2 mm (200 µm) Steady refractive errors (change < 0.5 diopter) during a year before Femto-LASIK Discontinuing soft contact lens and hard contact lens 1 and 4 weeks before the first examination, respectively

Exclusion criteria

Exclusion criteria: A history of any ocular surgery Systematic diseases such as thyroid disease or diabetes Presence of cataract Glaucoma or intraocular pressure (IOP) > 21 mmHg Any corneal irregularity or opacity Any posterior segment disorders Pregnancy or breastfeeding

Design outcomes

Primary

Measure	Time frame
Uncorrected distance visual acuity (UDVA). Timepoint: Before and 6 months after surgery. Method of measurement: Snellen Chart.;Corrected distance visual acuity (CDVA). Timepoint: Before and 6 months after surgery. Method of measurement: Trial frame, Snellen Chart.;Safety index. Timepoint: 6 months after surgery. Method of measurement: Calculation based on UDVA.;Efficacy index. Timepoint: 6 months after surgery. Method of measurement: Calculation based on UDVA and CDVA.	—

Measure

Time frame

Uncorrected distance visual acuity (UDVA). Timepoint: Before and 6 months after surgery. Method of measurement: Snellen Chart.;Corrected distance visual acuity (CDVA). Timepoint: Before and 6 months after surgery. Method of measurement: Trial frame, Snellen Chart.;Safety index. Timepoint: 6 months after surgery. Method of measurement: Calculation based on UDVA.;Efficacy index. Timepoint: 6 months after surgery. Method of measurement: Calculation based on UDVA and CDVA.

—

Secondary

Measure	Time frame
Refraction. Timepoint: Before and 6 months after surgery. Method of measurement: Auto-refractometer, trial frame, Snellen chart.;Corneal Aberrations. Timepoint: Before and 6 months after surgery. Method of measurement: Pentacam.	—

Countries

Iran (Islamic Republic of)

Contacts

Public ContactMojgan Pakbin

NOOR EYE Hospital

m_pakbin@razi.tums.ac.ir+98 21 8240 1675

Outcome results

None listed

Source: IRCT (via WHO ICTRP) · Data processed: Feb 4, 2026