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Author Spotlight: Anterior HR-OCT as a Non-Invasive Tool for Characterizing Ocular Surface Squamous Neoplasia

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Pellucid-like keratoconus.

Mazen M Sinjab¹, Lara N Youssef¹

¹Damascus University, Damascus, Syria.

|December 24, 2013

Summary

The claw pattern on anterior sagittal maps is not exclusive to pellucid marginal degeneration (PMD) and can appear in pellucid-like keratoconus (PLK). The "bell" sign on pachymetry maps is a key diagnostic indicator for PMD.

Area of Science:

Ophthalmology
Corneal Imaging
Refractive Surgery

Background:

Pellucid marginal degeneration (PMD) and pellucid-like keratoconus (PLK) are corneal ectatic disorders that can present with similar tomographic features.
Differentiating between PMD and PLK is crucial for appropriate patient management and treatment planning.

Purpose of the Study:

To investigate the tomographic characteristics of PLK using Scheimpflug-based tomography.
To identify and report a novel diagnostic sign on the pachymetry map (PM) for PMD.

Main Methods:

A retrospective analysis of 15 eyes (9 patients) with a "claw" pattern on the anterior sagittal map (ASM) was conducted.
Patients were classified into PMD (inferior corneal thinning) and PLK (no inferior thinning) groups.
Slitlamp biomicroscopy and Pentacam HR tomography (ASM, anterior elevation map, PM) were used for analysis.

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Main Results:

The "claw" pattern on the ASM was observed in both PMD and PLK groups.
The "bell" sign on the PM was present in all PMD cases (100%) but absent in PLK cases.
Cone location varied, with no clear correlation to the diagnosis.

Conclusions:

The "claw" pattern on the ASM is not pathognomonic for PMD and can be present in PLK.
The "bell" sign on the pachymetry map serves as a distinguishing diagnostic feature for PMD.
Cone location is not a reliable factor in differentiating PMD from PLK.