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Images of pellucid marginal degeneration software#
Corneo-scleral profile software from Pentacam tomography system. With the increased popularity of scleral lenses, corneo-scleral profiling is revolutionizing our understanding of anterior segment shape and our ability to design lenses that contour, with great precision, a surface that is now known to be quite asymmetric.įig 1. The two technologies are able to measure anterior and posterior corneal surfaces as well as a global area of corneal thickness.Ĭorneo-scleral profile analysis provides a detailed description of the anterior surfaces of the cornea and the sclera ( Figure 1). Specifically, Scheimpflug tomography uses a photographic imaging technology to provide a 360° analysis.Īnterior segment ocular coherence tomography (AS-OCT) can also provide similar imaging with even greater resolution in order to measure such structures as the epithelial corneal thickness. Ocular tomography provides imaging and analysis of multiple “slices” of the cornea and anterior segment. Tomography is a two-dimensional representation of a three-dimensional structure. Anterior segment OCT and Corneo-scleral Profiling These include, among others, an inability to measure the posterior cornea or the global corneal thickness. Still, there are some significant limitations to information obtained from Placido-based corneal topography that often hinder our understanding of the disease state. Curvature data is an excellent way to infer the optical characteristics of the visual system since the majority of refraction takes place at the anterior ocular surface interface.Įvident in these subsequent case examples, one can analyze curvature data of the anterior cornea in order to predict refractive performance. The cumulative analysis of corneal curvature data then creates a topography map. The closer the rings are to each other, the steeper the curvature is at that location. The separation of the concentric rings helps calculate inferred corneal curvature. Since the reflection is actually off of the tear layer, its stability or instability will have a dramatic effect on the outcomes. This imaging technology uses information processed from concentric rings reflected off of the anterior ocular surface in order to calculate corneal curvature. This article highlights cases that have incorporated many of the available advanced ophthalmic technologies that have made great strides in clinical success and efficiency. We can also now evaluate visual performance with and without contact lenses in ways that were only available in the optics laboratory in the past. With the advent of today’s advanced technologies, we are able to measure the shape of the cornea and the ocular surface with high precision, thus providing a far greater understanding of the disease state and an improved direction to better fit our patients.
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These patients typically were told that the only option available to them was corneal gas permeable contact lenses (GPs).įor fittings, practitioners used keratometry findings as a starting point and followed up with diagnostic GPs and a fluorescein evaluation. V isual rehabilitation with contact lenses for patients who suffer from irregular corneas was a hit or miss, and often frustrating, endeavor.