Characterization of postoperative LASIK ectasia features on higher-order aberration excimer ablation maps

• Published in: BMC ophthalmology 2023-12, Vol.23 (1), p.517-517, Article 517
• Main Authors: Wallerstein, Avi, Santhakumaran, Sangeetha, Tabunar, Lauren, Cohen, Mark, Gauvin, Mathieu
• Format: Article
• Language: English
• Subjects: Ablation; Ablation (Surgery); Astigmatism; Biomechanics; Contoura; Cornea; Cornea - surgery; Corneal Topography; Corneal Wavefront Aberration - diagnosis; Diagnosis; Dilatation, Pathologic; Ectasia; Higher-order aberration; Humans; Information processing; Islands; Keratomileusis, Laser In Situ - adverse effects; Keratomileusis, Laser In Situ - methods; Lasers; Lasers, Excimer - therapeutic use; Medical diagnosis; Myopia - surgery; Patients; Prospective Studies; Refraction, Ocular; Reproducibility; Software; Surgeons; Topography; Visual Acuity
• ISSN: 1471-2415; 1471-2415
• DOI: 10.1186/s12886-023-03263-y

To characterize anterior corneal higher-order aberration (HOA) excimer ablation map patterns in postoperative LASIK ectasia (POE) and to examine correlations between newly identified corneal HOA ablation map features of POE and known topographic indices. Prospective multicenter non-interventional descriptive study. A total of 28 eyes from 22 POE patients were enrolled. The postoperative HOA ablation map was derived from Topolyzer Vario corneal imaging at the time of POE diagnosis. Features that recurred were identified and then analyzed. Correlations to Orbscan indices were studied. An arrangement of two elliptical paracentral ablation islands, deep inferior and shallow superior, in direct mirror-like opposition to each other, were identified on all HOA maps. The paracentral islands were accompanied by peripheral ablation crescents. The deep paracentral inferior island 'hot spot' coincided with the topographical apical POE cone and was highly reproducible in angular position (249.3 ± 17.3°). There was significant variation in ablation depth (shallow superior island: 11.5 ± 6.9 μm and deep inferior island: 32.5 ± 18.8 μm). The superior crescents had high variability in depth (34.8 ± 18.9 μm). Strong correlations were found between the corneal irregularity index and the ablation depth difference between the deep and shallow paracentral islands (R = 0.96; P