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Underestimation of Intraocular Pressure (IOP) After LASIK and PRK: Systematic Review and Meta-Analysis
Stamatios Lampsas1, Efthymios Karmiris1, George D Kymionis2
12nd Department of Ophthalmology, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, 11528 Athens, Greece.
Journal of Clinical Medicine
|June 26, 2026
Summary
Refractive surgery like LASIK and PRK causes intraocular pressure (IOP) to be underestimated post-operation. Goldmann Applanation Tonometry showed the largest underestimation, emphasizing the need for careful tonometry method selection in glaucoma patients.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Glaucoma Management
Background:
- Refractive corneal surgery significantly alters corneal biomechanics and thickness.
- These changes can compromise the accuracy of intraocular pressure (IOP) measurements.
- Accurate IOP monitoring is crucial for managing glaucoma and preventing vision loss.
Purpose of the Study:
- To systematically review and meta-analyze the postoperative underestimation of IOP following laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).
- To quantify the magnitude of IOP underestimation using different tonometry methods.
Main Methods:
- Systematic review and meta-analysis adhering to PRISMA guidelines.
- Inclusion of studies evaluating pre- and postoperative IOP changes after LASIK and PRK.
- Utilized data from Goldmann Applanation Tonometry (GAT), Ocular Response Analyzer (ORA), and CORVIS ST.
- Searched major databases (PubMed, Scopus, Cochrane, ScienceDirect) up to December 2025.
Main Results:
- Analysis of 54 studies involving 4730 eyes revealed significant IOP underestimation post-LASIK across all methods.
- Goldmann Applanation Tonometry (GAT) showed the largest underestimation (MD: 3.23 mmHg) after LASIK.
- Post-PRK, GAT (MD: 2.04 mmHg) and ORA (MD: 2.46 mmHg) also demonstrated significant IOP underestimation.
Conclusions:
- LASIK and PRK procedures lead to a systematic underestimation of intraocular pressure.
- The degree of underestimation varies by tonometry method, with GAT being most affected.
- Appropriate selection of tonometry is vital for accurate IOP monitoring, particularly in at-risk glaucoma patients.
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