Agreement Between Subjective and Objective Refraction Using Autorefraction, Ray-Tracing, and Hartmann–Shack Aberrometry in Untreated Eyes Versus Eyes After Laser In Situ Keratomileusis

Agreement Between Subjective and Objective Refraction Using Autorefraction, Ray-Tracing, and Hartmann–Shack Aberrometry in Untreated Eyes Versus Eyes After Laser In Situ Keratomileusis - Refraction after LASIK

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

DRKS

Registry ID

DRKS00040311

Enrollment

Registered

2026-05-13

Start date

2026-03-10

Completion date

Unknown

Last updated

2026-06-01

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

Conditions

Patients post LASIK

Interventions

Group 1: Measurement of patients without prior ocular treatment Group 2: Measurement of patients after laser in situ keratomileusis

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Inclusion criteria

Inclusion criteria: - Patients = 18 years of age - Patients with LASIK in at least one eye performed more than 6 months prior to study inclusion, or patients without prior corneal treatment and otherwise healthy eyes - Sufficient physical and mental ability to cooperate during the examinations

Exclusion criteria

Exclusion criteria: -Patients with anterior or posterior segment abnormalities that may affect visual acuity or measurement accuracy (e.g. corneal scars, keratoconus, ectasia, advanced glaucoma, and/or macular degeneration) - Visual acuity < 0.5

Design outcomes

Primary

Measure	Time frame
The primary endpoint of the study is the agreement and deviation between subjective manifest refraction and objective refraction measurement using an autorefractometer (iTrace) in patients after LASIK compared with a control group without previous refractive corneal surgery. Subjective manifest refraction will be assessed once at the study visit. Spherical and cylindrical refractive values, including axis determination, will be measured by an optician using a trial frame and standardized visual acuity testing. During the same examination visit, objective refraction will be performed using the iTrace autorefractometer. The collected data from the post-LASIK group will subsequently be compared with the results of a control group without prior corneal surgery. The analysis will primarily evaluate differences in spherical refraction, cylindrical refraction, and spherical equivalent between the subjective and objective measurement methods.	—

Measure

Time frame

The primary endpoint of the study is the agreement and deviation between subjective manifest refraction and objective refraction measurement using an autorefractometer (iTrace) in patients after LASIK compared with a control group without previous refractive corneal surgery. Subjective manifest refraction will be assessed once at the study visit. Spherical and cylindrical refractive values, including axis determination, will be measured by an optician using a trial frame and standardized visual acuity testing. During the same examination visit, objective refraction will be performed using the iTrace autorefractometer. The collected data from the post-LASIK group will subsequently be compared with the results of a control group without prior corneal surgery. The analysis will primarily evaluate differences in spherical refraction, cylindrical refraction, and spherical equivalent between the subjective and objective measurement methods.

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Secondary

Measure	Time frame
1. Subjective manual refraction in patients after LASIK (gold standard) is highly similar to the refraction measured with the Pentacam® AXL Wave (Oculus, Wetzlar, Germany) and shows no statistically significant difference. 2. Subjective manual refraction in patients after LASIK (gold standard) is highly similar to the objective refraction measured using an autorefractor (Topcon Corporation, Tokyo, Japan) and shows no statistically significant difference. 3. After LASIK, the Pentacam® AXL Wave demonstrates a repeatability of objective refraction comparable to that of the iTrace (Tracey Technologies, Texas, USA).	—

Measure

Time frame

1. Subjective manual refraction in patients after LASIK (gold standard) is highly similar to the refraction measured with the Pentacam® AXL Wave (Oculus, Wetzlar, Germany) and shows no statistically significant difference. 2. Subjective manual refraction in patients after LASIK (gold standard) is highly similar to the objective refraction measured using an autorefractor (Topcon Corporation, Tokyo, Japan) and shows no statistically significant difference. 3. After LASIK, the Pentacam® AXL Wave demonstrates a repeatability of objective refraction comparable to that of the iTrace (Tracey Technologies, Texas, USA).

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Countries

Germany

Contacts

Public ContactPetra Dávidová

Universitätsklinikum Frankfurt

petra.davidova@unimedizin-ffm.de+4915117190984

Outcome results

None listed

Source: DRKS (via WHO ICTRP) · Data processed: Jun 11, 2026