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Review
. 2020 Dec;68(12):2699-2704.
doi: 10.4103/ijo.IJO_2119_20.

Topography-guided treatment in regular and irregular corneas

Shreyas Ramamurthy  1 , B Soundarya  1 , Gitansha S Sachdev  1
Affiliations
Review

Topography-guided treatment in regular and irregular corneas

Shreyas Ramamurthy et al. Indian J Ophthalmol. 2020 Dec.

Abstract

Over the last decade, refractive surgery has been revolutionized by advancements in ablation profiles, available for the treatment of both regular and irregular corneas. Advances in corneal imaging have helped highlight the presence of higher-order aberrations, the correction of which could result in a better quality of vision. Topographic measurements being static are more repeatable and pupil independent and therefore provide the ideal platform for correction of both lower and higher-order aberrations and could result in improved visual quality even in patients with seemingly regular corneas. The combination of topography-guided treatment with collagen cross-linking has further increased the scope of treating irregular corneas like keratoconus, post-laser in-situ keratomileusis ectasia, and pellucid marginal degeneration. This review delves into the current literature and guidelines available for the topographic treatment of regular and irregular corneas.

Keywords: Ablation; cornea; corneal topography; ectasia; excimer; keratoconus.

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Conflict of interest statement

None

Figures

Figure 1
Figure 1
Repeatable preoperative scans which are an essential prerequisite for subsequent treatment planning. The outliers are deselected from analysis
Figure 2
Figure 2
During the treatment, it's advisable to first keep the power at zero and check if the ablation profile matches with the sagittal curvature
Figure 3
Figure 3
Preoperative sagittal curvature of a patient undergoing combined topography-guided treatment with cross-linking
Figure 4
Figure 4
Ablation profile for the corresponding topography in Fig. 3, showing a myopic ablation over the area of the cone, and a broader mid-peripheral hyperopic ablation which will steepen the area anterior to it, thereby performing a regularization of the anterior cornea
Figure 5
Figure 5
Final treatment plan with the regularization and debulking of the cylindrical error with the extent of ablation around 50 μ
See this image and copyright information in PMC

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