WaveLight® ALLEGRO Topolyzer™ VARIO™

Alcon, USA
Non‑contact determination of corneal topography, keratometry, and pupillometry data, which are then transmitted directly to the laser suite during vision correction.

The Topolyzer™ VARIO™ diagnostic device is the next step in the evolution of the proven Topolyzer™ technology, combining non‑contact corneal topography, keratometry, and pupillometry in a single device.

The operation of the Topolyzer™ VARIO™ diagnostic device is based on a Placido disc system consisting of 22 measurement rings with 22,000 reference points, and includes optimized edge detection through sub‑pixel approximation down to 1/10 of a pixel.

Corneal elevation measurement is performed within a range of up to 1300 microns. The standard deviation at 1200 microns height is within 3–4 microns. Eyes with corneal opacities are readily measurable.

Calibration checks and automatic measurement tolerancing (performed by the built‑in real‑time keratometer) are conducted through a user‑friendly interface and ensure high reproducibility of results.

Efficient corneal parameter measurement is performed with user guidance displayed on a three‑dimensional model.

The high‑performance data processing unit automatically identifies the eye (OD/OS) and generates more reliable output data.

After digital signal evaluation, the data is transferred to a modern laptop via a high‑speed USB connection.

The software features a user‑friendly, intuitive interface. The data management system supports various types of analysis, data processing, display, as well as storage and backup, including:

• simple patient data entry (including additional patient comments);
• automatic keratoconus detection with corneal indices (shape, axis deviation, corneal asphericity) at various angles and diameters for comprehensive diagnostic assessment and interpretation of patient data;
• Zernike and Fourier analysis;
• map comparison mode (e.g., pre‑ and post‑keratoplasty);
• refraction map display mode;
• elevation map display mode;
• pupillometry and high‑resolution infrared eye imaging system;
• pupil center deviation determination function to assess pupil center shift under different lighting conditions and pupil sizes;
• automatic measurement quality check for cycloduction control (performed using the excimer laser software);
• integrated network connection to the WaveLight® EX500 excimer laser system for topography‑based treatment planning;
• data export function via USB connection to ALLEGRETTO WAVE®/Eye‑Q laser systems for topography‑based treatment planning;
• integrated data storage and backup function.

Measurement range:

• Corneal radius: 3 to 38 mm
• Refractive power: 9 to 99 D.

Laptop
With pre‑installed software.

T‑CAT Software Module for WaveLight® Excimer Laser Systems

The T‑CAT software module enables data transfer from the Topolyzer™ VARIO™ diagnostic device to WaveLight® excimer laser systems and facilitates personalized Wavefront‑Guided correction.

Clinical indications for Wavefront‑Guided treatment include:

• previous ablation center shift;
• enlargement of small optical zones;
• irregular ablation from prior treatments;
• previous radial keratotomy;
• previous keratoplasty.