The following is a summary of “Characterization of postoperative LASIK ectasia features on higher-order aberration excimer ablation maps’, published in the December 2023 issue of Opthalmology by Wallerstein et al.
Researchers conducted a retrospective study to analyze patterns of corneal higher-order aberration (HOA) in excimer ablation maps for patients with postoperative laser-assisted in situ keratomileusis (LASIK) ectasia (POE) and to investigate potential correlations between these newly identified HOA features and established topographic indices.
They enrolled 22 POE patients with a total of 28 eyes. The postoperative HOA ablation map was derived from Topolyzer Vario corneal imaging at the time of POE diagnosis. Recurring features were identified and analyzed, with correlations to Orbscan indices studied.
The results showed the presence of two elliptical paracentral ablation islands, deep inferior and shallow superior, in direct mirror-like opposition on all HOA maps. These paracentral islands were accompanied by peripheral ablation crescents. The ‘hot spot’ of the deep paracentral inferior island coincided with the topographical apical POE cone and showed high reproducibility in angular position (249.3 ± 17.3°). A notable variation was observed in ablation depth, with the shallow superior island at 11.5 ± 6.9 μm and the deep inferior island at 32.5 ± 18.8 μm. The superior crescents exhibited high depth variability (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<0.0001).
They concluded that distinct eye map patterns linked to post-LASIK ectasia offer promise for diagnosis and monitoring, but more research is needed.
Source: bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-023-03263-y
