September 2009 Advertorial Return to Homepage

Peter K. Kaiser, MD: The CONSTELLATION Vision System also offers the ability to micropulse and proportionately control reflux. The cassette on the CONSTELLATION allows an increase of fluid that is proportional to the circumstances. For example, if you are operating on a patient with diabetes who begins to bleed, you can switch to proportional reflux mode and the fluid will increase to the extent where it effectively pushes the blood out of the way.

  • Share
  • E-mail
  • Print

In the past 5 years, there have been significant advancements made to illumination for vitreoretinal procedures. The illumination on the ACCURUS system (Alcon Laboratories, Inc., Fort Worth, TX) has improved from using a halogen bulb to xenon light source technology. In this article, I will describe the illumination technology on the new CONSTELLATION Vision System (Alcon Laboratories, Inc.).

SYSTEM IMPROVEMENTS
The CONSTELLATION system has four ports for illumination, although the system allows the use of only two ports at any given time. A surgeon retains an advantage from the additional ports, because a combination of any two of these can be used simultaneously.

The improvements to the illumination system on the CONSTELLATION include: brightness and color that enhance visualization and enables surgeons to have visibility in corners of the retina that were previously unable to be viewed; a longer bulb life than on the ACCURUS, which could decrease costs because the bulb needs to be changed less frequently; and the ENGAUGE Radio Frequency Identification (RFID) probe recognition, which makes setup much easier and regulates the initial light output based on gauge and type of fiber optic.

XENON TECHNOLOGY
The new xenon bulb on the CONSTELLATION system provides bright, white xenon light to the maximum level allowed under current FDA irradiance limits.

The halogen light on the original ACCURUS was fairly faint and yellowish, and provided limited visibility. The xenon bulb on the ALCON AHBI (ACCURUS High- Brightness Illuminator), provided improvement in brightness and was filtered toward blue. The chromaticity diagram in Figure 1 shows the color spectrum of the ACCURUS halogen light, the ACCURUS xenon, the CONSTELLATIONxenon, and the MILLENNIUM (Bausch & Lomb, Rochester, NY) metal-halide light source.

The xenon light source on the CONSTELLATION has moved away from blue light, retaining the white light, which has high-energy wavelengths that are easily absorbed by the retina.

The design of the illuminator (Figure 2) is different from other systems in that there is not a beam splitter, which can degrade the quality and intensity of the light. Rather, the CONSTELLATION illuminator uses a whole mirror system so that that same image is reflected to two separate pathways. The collimating lenses focus all light into the ports.

BULB LIFE
The CONSTELLATION has been designed for more consistent light output over time. In the first 200 hours, the light output is extremely stable. The orientation of the lamp produces highly uniform illumination and the precise design and alignment of the fiber and bulb capture more light for better uniformity and efficiency.

The CONSTELLATION system indicates how many hours of illumination have been used. The life of the long-lasting xenon bulb is tracked by the system and provides total lamp hour and colored indicator ring feedback on lamp life: the green ring indicates from 0 to 200 hours; the yellow ring indicates from 201 to 400 hours; and the orange ring indicates from 401 to 800 hours.

RFID SYSTEM
The ENGAUGE RFID system automatically recognizes the type of Alcon device that is being connected, and populates the proper probe and gauge size into the system. The ENGAUGE RFID also provides a standard default setpoint feature that utilizes the probe and gauge information and automatically puts the surgeon at the default. For example, if the surgeon is using a straight or BULLET Wide-Angle Illuminator (Alcon Laboratories, Inc.), the system will default to a consistent 8 to 10 lumens light output. The surgeon maintains the ability to override the system and increase illumination, if needed, to the maximum US Food and Drug Adminstration-allowed output.

FIBER OPTICS
One of the challenges of 25-gauge surgery using halogen illumination was that the fiber itself is half the size of a 20-gauge system, reducing light by approximately 70%. In 20-gauge surgery, the halogen output is 10 lumens, whereas with 25 gauge, the output is reduced to 3 lumens, which is inadequate for surgery. Even with the use of illuminated instruments, it is difficult to see at that power. The new SAPPHIRE Wide- Angle Illuminator (Alcon Laboratories, Inc.) has a 750-μm fiber that goes from the machine all the way into the handle of the light pipe. The viewing angle on the SAPPHIRE is greater than 106° for 20-, 23-, 25-gauge surgery, and the light fiber can be used with any of the Alcon light sources.

SUMMARY
The improved illumination on the CONSTELLATION Vision System, in terms of brightness, quality, stability, and ease of use has answered many of the difficulties of visualization that surgeons have experienced with small-gauge surgery. The retina can now be viewed with more clarity, and the improved angle of the light will now allow surgeons to see a wider area of the retina when operating.

Roger Novack, MD, PhD, FACS, is a Partner in the Retina Vitreous Associates Medical Group, Los Angeles, California and Assistant Clinical Professor at the Jules Stein Eye Institute Geffen School of Medicine, University of California Los Angeles. Dr. Novack is a paid consultant of Alcon Laboratories and Optos Corporation. Dr. Novack can be reached at +1 213 483 8810; fax: +1 213 481 1503; or via e-mail: RogNov@laretina.com.

You must be logged in to leave a comment.