Effects of SMILE on intraocular pressure and corneal biomechanics: a systematic review and meta-analysis.

Stamatios Lampsas, Gerasimia-Marina Chardalia, Efthymios Karmiris, George D Kymionis, Irini Chatziralli

Abstract readSystematic ReviewMeta-AnalysisReview

In one paragraph

Synthesis in International ophthalmology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it

0cells of the map it votes in

0citing papers in PubMed

–field-weighted citation impact

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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

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

5 authors.

Stamatios LampsasSecond Department of Ophthalmology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, 1, Rimini Street, 12462, Haidari, Athens, Greece. lampsas.stam@gmail.com.ORCID https://orcid.org/0000-0001-6481-0000

Gerasimia-Marina ChardaliaSecond Department of Ophthalmology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, 1, Rimini Street, 12462, Haidari, Athens, Greece.ORCID http://orcid.org/0009-0000-3830-1149

Efthymios KarmirisSecond Department of Ophthalmology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, 1, Rimini Street, 12462, Haidari, Athens, Greece.ORCID http://orcid.org/0000-0002-4091-9236

George D KymionisFirst Department of Ophthalmology, Medical School, "G. Gennimatas" Hospital, National and Kapodistrian University of Athens, 11528, Athens, Greece.ORCID http://orcid.org/0000-0003-1618-8047

Irini ChatziralliSecond Department of Ophthalmology, School of Medicine, National and Kapodistrian University of Athens, Attikon University Hospital, 1, Rimini Street, 12462, Haidari, Athens, Greece.ORCID http://orcid.org/0000-0001-8523-1024

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeSmall incision lenticule extraction (SMILE) is a popular flapless refractive procedure for myopia and myopic astigmatism, although postoperative corneal biomechanical changes may affect intraocular pressure measurements and glaucoma assessment. This systematic review and meta-analysis aimed to quantify the postoperative underestimation of IOP and changes in corneal biomechanical parameters following SMILE. MATERIALS AND

methodsA comprehensive literature search of PubMed, Cochrane Library, ScienceDirect, and Scopus databases was performed up to April 30, 2026, according to PRISMA guidelines. Observational studies reporting preoperative and postoperative IOP measurements after SMILE using Goldmann applanation tonometry (GAT), Ocular Response Analyzer (ORA), or Corvis ST were included. Secondary outcomes included changes in corneal hysteresis (CH) and corneal resistance factor (CRF).

resultsSeventeen studies involving 1177 eyes were analyzed. Postoperative IOP was significantly reduced across all tonometric modalities. The pooled mean reduction was greatest with GAT (MD: 3.47 mmHg; 95% CI 2.85-4.10), followed by ORA (MD: 2.50 mmHg; 95% CI 2.06-2.94) and Corvis ST (MD: 1.52 mmHg; 95% CI 0.62-2.42) (all p < 0.001). Significant postoperative reductions were observed in CH (MD: 1.84 mmHg) and CRF (MD: 3.01 mmHg), indicating decreased corneal biomechanical stability after SMILE.

conclusionsSMILE leads to significant underestimation of IOP measurements and measurable biomechanical weakening of the cornea. Clinicians should interpret postoperative IOP values cautiously, even when using biomechanically corrected tonometric devices.

Indexed as

AstigmatismCorneaCorneal Surgery, LaserIntraocular PressureMyopiaBiomechanical PhenomenaHumansTonometry, OcularCorneal biomechanicsCorneal hysteresisIntraocular pressureRefractive surgerySMILE

Identifiers

PMID42635859

DOI10.1007/s10792-026-04194-5

PMCPMC13503405

What OpenQuestion holds

Textmetadata

Read underepoch 390

Registered trials

None linked

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.