Evidence map›Paper›PMID 40190999›Full record

ArticleClinical ophthalmology (Auckland, N.Z.)2025

Patterns of Corneal Astigmatism in Eyes Post Myopic Laser Keratorefractive Surgery.

Aaron W Ng, Stephen Stewart, Tun Kuan Yeo

Abstract read
In one paragraph

Article in Clinical ophthalmology (Auckland, N.Z.), 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

3 authors.

Aaron W NgDepartment of Ophthalmology, Tan Tock Seng Hospital, Singapore.
Stephen StewartDepartment of Ophthalmology, Tan Tock Seng Hospital, Singapore.ORCID 0000-0002-8682-825X
Tun Kuan YeoDepartment of Ophthalmology, Tan Tock Seng Hospital, Singapore.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: In the absence of a measured posterior keratometry input, toric intraocular lens power formulae in patients with a history of myopic laser keratorefractive surgery (M-LVC) predict the posterior corneal astigmatism. These formulae assume that the posterior corneal curvature is essentially unchanged post M-LVC and hence its characteristics in this demographic of patients would be the same as virgin eyes. We aim to describe astigmatism measured by a swept-source optical coherence tomography biometer in such patients. Patients and Methods: Retrospective consecutive case review of eyes with prior M-LVC, followed by subsequent cataract surgery. Pre-operative biometric data was collected using the IOLMaster 700 (Carl Zeiss Meditec). Magnitude and orientation of the steep and flat meridian of standard keratometry (SK), posterior keratometry (PK) and total keratometry (TK) were recorded. Relationships between corneal astigmatism, age, and gender were assessed. Statistical analysis was performed using linear regression, Mann Whitney Results: A total of 341 eyes (218 patients) were studied. Mean SK was 39.65D ± 2.16D. Mean PK was -5.82D ± 0.24D. Mean TK was 39.15D ± 2.34D. SK astigmatism (SKA) was predominantly vertical (57.8%, n = 197 eyes) with a mean magnitude of 0.85D ± 0.47D. Posterior corneal astigmatism (PCA) was predominantly vertical (91.5%, n = 312 eyes) with a mean magnitude of 0.29D ± 0.14D. TK astigmatism (TKA) was predominantly vertical (42.2%, n = 144 eyes) with a mean magnitude of 0.83D ± 0.47D. There was a positive correlation between magnitude of TKA with SKA and PCA (P < 0.001). A negative correlation between age and magnitude of SKA, PCA and TKA was noted (P < 0.001). No statistically significant relationship with gender was noted. Conclusion: PCA orientation of post M-LVC eyes is similar to published data of virgin eyes. This reinforces the assumption made in toric intraocular lens power formulae that posterior corneal astigmatism in these eyes share the same characteristics as virgin eyes.

Indexed as

biometryintraocular lens (IOL)IOL power calculation formulaeLASIKPRKtoric

Identifiers

PMID40190999
PMCPMC11970278

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