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. 2025 Sep;14(9):2141-2154.
doi: 10.1007/s40123-025-01199-8. Epub 2025 Jul 10.

Early Posterior Corneal Changes and Belin/Ambrósio Scores Following Photorefractive Keratectomy: A Pentacam Study

Konuralp Yakar  1 , Göksu Alaçamlı  2 , Gökhan Özgür  3
Affiliations

Early Posterior Corneal Changes and Belin/Ambrósio Scores Following Photorefractive Keratectomy: A Pentacam Study

Konuralp Yakar et al. Ophthalmol Ther. 2025 Sep.

Abstract

Introduction: To evaluate early postoperative changes in the posterior corneal surface, anterior chamber parameters, and Belin/Ambrósio Enhanced Ectasia Display (BAD) scores following photorefractive keratectomy (PRK) using Pentacam tomography.

Methods: This observational study included 102 eyes of 51 patients (mean age 28.43 ± 6.27 years) undergoing alcohol-assisted PRK for myopia and/or astigmatism. Preoperative and 1-month postoperative assessments were performed using the Pentacam system, measuring, anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness, posterior keratometry, posterior elevation, and BAD scores. PRK was conducted with a WaveLight® EX 500 excimer laser, followed by mitomycin-C application. Statistical analysis utilized paired t-tests and Pearson's correlation.

Results: At 1 month post-PRK, ACV significantly decreased (p < 0.01), while ACD reduction was not significant (p = 0.40). Posterior keratometry (K1, K2, Kmean) and astigmatism decreased (p < 0.01), with a mean posterior elevation increase of -2.50 ± 2.94 µm (p < 0.01). A weak negative correlation was observed between maximum posterior elevation difference and ablation depth (p = 0.03, r = -0.20) and ablation depth/preoperative pachymetry ratio (p = 0.03, r = -0.20). BAD-D scores (Dp, Dt, Da, total D) significantly increased (p < 0.01), except for Df (p = 0.41). No correlation was found with preoperative pachymetry or residual stroma.

Conclusions: PRK induces minimal posterior corneal protrusion and BAD score changes at 1 month, potentially mimicking early ectasia. Multimodal testing is advised for accurate ectasia detection. Larger, longer-term studies are needed to validate these findings.

Keywords: BAD scores; Keratoectasia; Pentacam; Photorefractive keratectomy; Posterior cornea.

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Conflict of interest statement

Declarations. Conflict of Interest: Konuralp Yakar, Göksu Alaçamlı, and Gökhan Özgür have nothing to disclose. Ethical Approval: The study protocol received approval from the Ethical Committee of Ondokuz Mayıs University (B.30.2.ODM.0.20.08/256) and adhered to the principles outlined in the Declaration of Helsinki. Informed consent was obtained from all participants.

Figures

Fig. 1
Fig. 1
Both ACD and ACV decreased following photorefractive keratectomy, but this change was significant only in ACV (p < 0.01). ACD anterior chamber depth, ACV anterior chamber volume
Fig. 2
Fig. 2
Maximum posterior elevation difference values and number of patients
Fig. 3
Fig. 3
Correlations between maximum elevation back difference, ablation depth, and ablation depth/pachymetry ratio
See this image and copyright information in PMC

References

    1. Chan TC, Liu D, Yu M, Jhanji V. Longitudinal evaluation of posterior corneal elevation after laser refractive surgery using swept-source optical coherence tomography. Ophthalmology. 2015;122:687–92. 10.1016/j.ophtha.2014.10.011. - DOI - PubMed
    1. Chen T, Li N, Ge T, et al. Regional analysis of posterior corneal elevation after laser refractive surgeries for correction of myopia of different degrees. Indian J Ophthalmol. 2024;72:824–30. 10.4103/IJO.IJO_1927_23. - DOI - PMC - PubMed
    1. Pniakowska Z, Jurowski P, Wierzbowska J. Clinical evaluation of corneal biomechanics following laser refractive surgery in myopic eyes: a review of the literature. J Clin Med. 2022;12:243. 10.3390/jcm12010243. - DOI - PMC - PubMed
    1. Soundarya B, Sachdev GS, Ramamurthy S, Dandapani R. Ectasia after keratorefractive surgery: analysis of risk factors and treatment outcomes in the Indian population. Indian J Ophthalmol. 2020;68:1028–31. 10.4103/ijo.IJO_1592_19. - DOI - PMC - PubMed
    1. Zhou W, Wang H, Zhang X, et al. Management of corneal ectasia after LASIK with phototherapeutic keratectomy combined with photorefractive keratectomy and collagen cross-linking. J Ophthalmol. 2019;2019:2707826. 10.1155/2019/2707826. - DOI - PMC - PubMed

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