Basis Features
The Pentacam® / Pentacam® HR software allows customized and objective standardized evaluation of corneal optical densitometry. It is displayed as a color coded map over its full depth and area and can be assessed individually in different layers and zones. The respective layer depth and zone size are displayed in the two Scheimpflug images as well as in a colored or a grey scaled map.
For study and normative data analysis it is displayed in fixed layers and zones in the table chart. The objective analysis of corneal optical density allows the detection of corneal Fuchs dystrophy or corneal scars for example. It provides an objective follow-up before and after CXL, PRK, LASIK, DSEK, etc. as well.
The Indices Report allows a quick screening of new patients to detect abnormalities. The intuitive guide recommends further displays to look at.
Important parameters of the anterior eye segment, displayed with the Pentacam® / Pentacam® HR software, are analyzed and validated in published papers and articles.
Their normal (green) and pathological (red) distribution is displayed in diagrams.
This presentation provides an intuitive, quick but comprehensive overview.
For detailed assessment, the literature source used is also mentioned. Based on individual results, the navigation bar recommends further displays to review to get additional information
The pre-op planning for implanting a corneal ring is a combination of several parameters. The Corneal Rings Display includes all relevant information for this purpose.
The table chart in the upper center contains the minimum thickness for manual dissection technique or using a Femto laser to design the channel.
Below the table chart, the 3rd and the 5th order coma amount and axis are shown which together with the astigmatism axis helps orientating the ring(s). The colored maps are helpful for the qualitative inspection of the corneal properties.
The corneal ring display in combination with the link to the external Ferrara Ring calculator software realizes an automated and comprehensive clinical use. The Ferrara Ring calculator imports all necessary data from the Pentacam® and suggests the best ring type and orientation axis.
Please keep in mind that the mentioned external software might not be available in your country.
The Scheimpflug image gives a complete representation of the anterior chamber, extending from the endothelium to the posterior surface of the lens. Any opacities of the cornea or lens are made visible and quantified objectively. The chamber angle is also shown in the Scheimpflug image. This can assist in the diagnosis of closed-angle glaucoma, for ex.. After keratoplastic surgery it can be used to analyse the position of the implant and follow up the healing process. The Scheimpflug image is also excellently suited for consulting with the patient.
The corneal thickness progression analysis is calculated using concentric rings, starting at the thinnest point and extending to the periphery. Using this evaluation differences between normal corneas and Keratoconus corneas can be detected and used to identify very early changes. The results are displayed in two diagrams. For an objective comparison and analysis the progression index is calculated.
This display contains the most important information for a quick screening of patients who are interested in corneal surgery. The keratometry, pachymetric progression, topographically keartoconus evaluationis shown. Moreover the corneal topography, pachymetry and the posterior elevation map is displayed too.
The Scheimpflug technology allows the measurement of both corneal surfaces. Based on the accurate measurement a Zernike analysis and corneal wavefront are calculated. The display shows the elevation (surface) based Zernike analysis as well as the ray traced corneal wavefront. The corneal wavefront is calculated via ray tracing for the anterior, posterior and total cornea. It is displayed in comparison to a normal population. The deviation from the standard allows a quick detection of abnormalities. For this purpose the refractive indices of corneal tissue and the aqueous fluid are used. These calculations are not possible with Placido based topographers.
The pre-op assessment of anterior chamber conditions are one important part of the patient selection process to evaluate if a phakic IOL might be beneficial. The OCULUS Pentacam® HR provides a pre-op simulation of the iris fixated phakic IOL. Depending to the selected pIOL type and patients refraction the software calculates the necessary refractive pIOL power using the van der Heyde formula. The position of this specific pIOL in the anterior chamber is automatically calculated in 3D and represented in the Scheimpflug images. The minimal distances between:
- the pIOL and the crystalline lens,
- the pIOL and the endothelium
are calculated automatically in 3D and displayed numerically and in a color map. Moreover the growing of the crystalline lens over the years is calculated and the forward move of the pIOL is shown and quantified too. The results can be shown to the patient. This software module is available for the Pentacam® HR only.
The Corneal Power Distribution Display is a sophisticated tool to assess in detail corneal power. The Sim K’s, True Net Power and Total Corneal Refractive Power are displayed in a table chart. The reference for the calculation can be switched:
- from apex to pupil to see possible changes, especially after refractive surgery
- to calculate corneal power on a ring (usual Keratometry) or in a zone which is for example useful for IOL calculation for patients who underwent RK in the past
- to different zone from 1mm up to 8mm
Moreover the presentation of Sim K’s (anterior corneal surface) and Total Cornal Refractive Power in one table chart displays the influence of the posterior corneal surface which is essential for toric IOL implantation. To complete the display the corneal power can be assessed everywhere on the cornea to see its distribution in a diagram in order to assess corneal optical properties for example multifocality, the effects of corneal flattening after CXL (Corneal Cross Linking).
The iris camera and optic were improved to display the iris image as a front photo and to determine HWTW (horizontal white to white) automatically. This supports in selection of the correct size of the ICL as well as in sizing of contact lenses. Moreover the ophthalmologist can assess pupil shape and identify landmarks which are needed for surgery.
The Keratometry can be displayed as an overlay to determine the corneal power in the pupil area. All colored maps can be displayed as an overlay too. The Pentacam®/ Pentacam® HR which are currently shipped have the new iris camera with the improved optic design built in. Older systems in the field can be upgraded depending on their age. For further information please contact your local distributor.
The Fourier Analysis dismantles the anterior corneal surface. In detail:
- the spherical component displays the arithmetic mean of all radii of curvature for each ring; the spherical eccentricity is calculated which is below 0.85 for normal eyes.
- the decentration or asymmetry of the astigmatic component which is for normal eyes below 0.43, higher number might be a sign for Keratoconus
- the regular astigmatic component is calculated in the center and in the periphery; from experience the amount and axis position of the central, regular astigmatism based on Fourier Analysis corresponds better with the subjective refraction
- the irregularities of the cornea which can not be corrected by sphere, cylinder or prism; the mean value of a normal cornea is below 0,03mm
The early detection and follow-up of corneal shape abnormalities, such like keratoconus and others is a vital part of the eye specialist’s everyday practice. The Pentacam is equipped with sensitive detection software which performs objective topographic classification of corneal shape abnormalities, such like keratoconus based on various indices.
The Pentacam®/Pentacam®HR offers several comparison displays. Up to four exams can be loaded and analysed in order to see progression over time. Every single map and almost every parameter can be assessed. The example used in the screenshots display a corneal topography of before and after CXL (Corneal Cross Linking), one shows the maps and the other display the progression of anterior segment parameters.
The Pentacam®/Pentacam®HR software allows the presentation of two exams in one display. This is very helpful to show the right and left eye together to assess possible difference, e.g. asymmetric Keratoconus.
Applications:
- Keratoconus detection
- Pre-surgical planning of refractive corneal surgery
- Follow-up after corneal surgery
- Calculation of IOL refractive power
- Planning of astigmatism reducing incisions (LRI)
- Follow-up after refractive surgery (pre-post LASIK)
Details:
The rotating measurement principle guarantees high resolution of the data points in the central cornea. Topographic analysis of the anterior and posterior corneal surfaces is based on the measured real elevation data.
- Sagittal, tangential-radial maps, refractive maps
- Various elevation maps in relation to freely selectable reference bodies
- True Net Power – calculation of real refractive power taking the posterior corneal surface into account
- Various four-colour maps, pre-set or individually configurable
- Differential and comparative representations of different examinations
Applications:
- Pre-surgical planning of refractive corneal surgery
- Glaucoma screening
- Keratoconus detection and quantification
- IOP evaluation taking into account measured corneal thickness based on various formulas (for ex. the Dresden correction table)
Details:
An overview display in colour shows the corneal thickness from limbus to limbus. The measured values can be displayed in a pre-determined grid or represented manually at any point at a mouse click.
Automatic representation of:
- corneal thickness in the centre of the pupil
- corneal thickness in the apex
- the thinnest point of the cornea
- corneal volume
This colour map serves to depict the elevation data of the corneal anterior and posterior surfaces using different reference bodies.
This colour map serves to depict the elevation data of the corneal anterior and posterior surfaces using different reference bodies. It offers reliable assistance in the diagnosis of keratoconus, for ex., especially as elevation data are less prone to errors resulting from poor fixation by the patient than are curvature data.
Applications:
- Pre-surgical planning of implantation of phakic lenses
- Glaucoma screening
- Pre- to post-operative comparison of changes in the anterior chamber, for ex. after an iridectomy
Details:
- Automatic calculation of
- chamber angle
- chamber volume
- chamber depth
Anterior Segment Tomography
The rotatable, swivelable 3D model of the eye proves to be an enormous help when consulting with patients, as it permits the patient to see his eye from all sides so that irregularities can easily be explained.
Applications:
- Quick overview of the acquired data
- Changes which become visible in the Scheimpflug image are represented amazingly well in a 3D model.
Details:
The rotatable, swivelable 3D model of the eye proves to be an enormous help when consulting with patients, as it permits the patient to see his eye from all sides so that irregularities can easily be explained.
This overview display contains all the information required for a qualitative assessment of the cornea. It shows corneal thickness distribution and a corneal thickness map, a sagittal curvature map of the anterior corneal surface, an indices-based topometric quantification of the anterior corneal surface and an elevation map of the posterior corneal surface.
Applications:
- Overview display for the refractive surgeon
- Topometric and pachymetric keratoconus analysis
Detail:
This overview display contains all the information required for a qualitative assessment of the cornea. It shows corneal thickness distribution and a corneal thickness map, a sagittal curvature map of the anterior corneal surface, an indices-based topometric quantification of the anterior corneal surface and an elevation map of the posterior corneal surface. The asphericity of the cornea is described as a function of various zones and meridians.