Evidence map›Paper›PMID 41781518›Full record

ArticleOphthalmology and therapy2026

Comparing Efficacy and Corneal Biomechanics Between KLEx and KLEx Xtra in High Myopia: A 1-Year Prospective Randomized Study.

Jing Cong, Xueqi Lin, Jiayue Yuan, Xinran Li, Wangyuan Liu, Xiuyu Mao, Changyue Zheng, Shichu Liu, Qianhong Feng, Chunqiong Dong and 3 more

Registry-linked trialAbstract read
In one paragraph

Article in Ophthalmology and therapy, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06992011 (A Randomized Controlled Trial Comparing Clinical Effectiveness of SMILE Versus SMILE Xtra in Myopia), which is not on this map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT06992011 narecruitingnot on this map

A Randomized Controlled Trial Comparing Clinical Effectiveness of SMILE Versus SMILE Xtra in Myopia

TypeinterventionalSponsorShanghai Zhongshan HospitalRan2023 to 2027Enrolled300ConditionsMyopiaArmsSMILE, SMILE Xtra
3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

13 authors.

Jing Cong *Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Xueqi Lin *Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Jiayue Yuan *Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Xinran LiDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Wangyuan LiuDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Xiuyu MaoDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Changyue ZhengShanghai Geriatric Medical Center, Shanghai, 201104, People's Republic of China.
Shichu LiuDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Qianhong FengDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Chunqiong DongDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China.
Chenli FengDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China. fseam@126.com.
Yuanzhi YuanDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China. yuan.yuanzhi@zs-hospital.sh.cn.
Jinhui DaiDepartment of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, 20032, People's Republic of China. dai.jinhui@zs-hospital.sh.cn.

Funding

Hospital-site Cooperation Project (life and health field) of Shanghai Xuhui District 23XHYD-02Steel and Iron Foundation of Hebei Province 24ZR1410200
6 · The paper itself

Abstract

introductionThis work aims to compare the 12-month changes in refractive outcomes, safety, efficacy, predictability, corneal biomechanics, and corneal topography between keratorefractive lenticule extraction (KLEx) and KLEx combined with prophylactic corneal collagen cross-linking (KLEx Xtra).

methodsA prospective, randomized, controlled trial was conducted with 80 eyes in each group. The primary endpoint was the manifest refraction spherical equivalent (MRSE) at 12 months postoperatively in both groups. Secondary endpoints included visual outcomes, corneal biomechanical parameters, and topographic changes. The study has been registered at ClinicalTrials.gov (No. NCT06992011).

resultsAt the 12-month follow-up, a small statistically significant difference in MRSE was observed between the two groups (KLEx Xtra: - 0.02 ± 0.38 D and - 0.17 ± 0.35 D, p = 0.047). Both groups demonstrated comparable and favorable safety and efficacy indices at 12 months. While corneal haze occurred universally early after the CXL procedure, it persisted in a subset of eyes for up to 6 months. At 12 months postoperatively, both KLEx and KLEx Xtra groups showed significant changes in corneal biomechanical parameters. The KLEx Xtra group exhibited enhanced biomechanical strength, with a significant improvement in parameters such as first applanation velocity (A1 V), Corvis biomechanical index (CBI), stiffness parameter at applanation 1 (SP-A1), and stress-strain index (SSI), compared to the KLEx group at 12 months postoperatively (p < 0.05). There were no significant differences between the two groups in corneal topographic parameters up to 6 months postoperatively, but at 12 months, the KLEx group showed significantly higher steep K value of anterior corneal surface (K2 F) compared to the KLEx Xtra group.

conclusionsKLEx Xtra demonstrates superior refractive accuracy with a reduced risk of myopic regression within 12 months of follow-up while also enhancing corneal biomechanical strength, making it a viable alternative for people with high myopia.

trial registrationThe study has been registered at Clinicaltrials.gov, NCT06992011 (retrospectively registered at May 7, 2025).

Indexed as

Corneal biomechanicsCorneal collagen cross-linkingHigh myopiaKLEx

Identifiers

PMID41781518
PMCPMC13046917

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Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.