Comparison of Persistent Postoperative Discomfort 1 Year after Keratorefractive Lenticule Extraction and Implantable Collamer Lens Implantation

Evidence database / Studies / kim-chung-2025-klex-icl-persistent-discomfort

324enrolled patients*

324enrolled eyes*

2structured arms

365maximum standardized days follow-up

* Descriptive sum of reported arm counts. “≥” indicates that one or more arm counts were not reported; missing values are not treated as zero.

Study arm

Keratorefractive lenticule extraction (KLEX)

SMILEVisuMax Femtosecond Laser

Population

Patients: 227
Eyes: 227
Bilateral treatment: Yes
Age range: Not reported
Sphere range: -7 to -0.5 D
Cylinder range: -3.5 to 0 D
Spherical equivalent: Not reported
Corneal thickness: Not reported

Eligibility definition

Inclusion
Myopia from -0.5 to -7.0 D, central corneal thickness greater than 480 μm, calculated postoperative residual bed thickness greater than 300 μm, age at least 19 years, CDVA 20/30 or better, astigmatism up to -3.5 D, and stable refraction for more than 2 years.

Exclusion
Severe dry eye, obvious corneal scarring, active ocular or systemic disease, glaucoma or retinal disease, previous ocular surgery, pregnancy, or lactation.

Reported outcomes by follow-up

Outcome	Follow-up	Follow-up sample	Result	Reported fraction	Provenance
Postoperative night glare symptoms	1 year	227 eyes	50.2%	denominator: 227 patients	VERIFIED Source · Abstract; Figure 1
Postoperative halos symptoms	1 year	227 eyes	48.9%	denominator: 227 patients	VERIFIED Source · Abstract; Figure 1

Complications

No structured complication observations are available for this arm. This means “not reported in this dataset,” not zero complications.

Study arm

EVO Visian ICL V4c implantation

ICLEVO Implantable Collamer Lens

Population

Patients: 97
Eyes: 97
Bilateral treatment: Yes
Age range: Not reported
Sphere range: -18 to -0.5 D
Cylinder range: -3.5 to 0 D
Spherical equivalent: Not reported
Corneal thickness: Not reported

Eligibility definition

Inclusion
Myopia from -0.5 to -18.0 D, anterior chamber depth greater than 2.8 mm, endothelial cell density at least 2,000 cells/mm², age at least 19 years, CDVA 20/30 or better, astigmatism up to -3.5 D, and stable refraction for more than 2 years.

Exclusion
Severe dry eye, obvious corneal scarring, active ocular or systemic disease, glaucoma or retinal disease, previous ocular surgery, pregnancy, or lactation.

Reported outcomes by follow-up

Outcome	Follow-up	Follow-up sample	Result	Reported fraction	Provenance
Postoperative night glare symptoms	1 year	97 eyes	64.9%	denominator: 97 patients	VERIFIED Source · Abstract; Figure 1
Postoperative halos symptoms	1 year	97 eyes	63.9%	denominator: 97 patients	VERIFIED Source · Abstract; Figure 1

Complications

No structured complication observations are available for this arm. This means “not reported in this dataset,” not zero complications.

Study design

Retrospective single-center comparative study using a standardized questionnaire 1 year after bilateral KLEX or ICL implantation; the right eye was analyzed for each patient.

Country: South Korea
Publication-reported places: Onnuri Smile Eye Clinic, Seoul · Onnuri Eye Hospital, Jeonju
Multicenter: No
Prospective: No
Randomized: No
Source type: RETROSPECTIVE
Regulator: Not reported

Place metadata may refer to a treatment site, institution or author affiliation. Confirm its role in the linked publication.

Limitations and notes

Persistent glare and halo percentages are source-reported questionnaire results. Numerators were not reported and have not been inferred. The two procedure groups differed substantially in baseline myopia, so the between-group percentages should not be interpreted as randomized comparative effectiveness.

Missing fields are not interpreted as negative findings. Arm counts may not be additive in all study designs.

Study evidence level
A simple, non-GRADE hierarchy based on design: randomized and large regulatory trials are high; prospective cohorts moderate; retrospective observational studies low. Manual review can override this label.