Laser - Green, Red, Yellow For Sale - Page 2

Tips and Guidelines for Buying an Ophthalmic Retinal Laser

Low-power (810 nm wavelength) Diode lasers, with gallium arsenide as the active medium. The lasers can be incorporated into a slit-lamp or indirect opthalmoscope by a flexible fiber-optic cable. They are used for coagulation of abnormal vascular tissue in the retina, and other photocoagulation procedures.

Tips for Buying an Ophthalmic Retinal Laser

1. This is the delivered power for the different beams: 3 W for an argon blue-green beam, 1 W for an argon green beam, 1 W for a dye beam, 1.5 W for a krypton green beam, 1.5 W for a krypton yellow beam, 1 W for a krypton red beam, and 1 W for a Nd:YAG beam. The following lasers should have principal wavelengths of 530-540 nm: argon, dye, krypton, and frequency doubled Nd:YAG lasers. The requirements of the unit include: single and repeat delivery modes, exposure duration of 0.01 to 2 seconds, repeat time of 0.1 to 2 seconds, a spot diameter of 50 to 1,000 mm, a slit lamp, an intraocular probe, a hand piece, and an indirect ophthalmoscope. An Nd:YAG laser should use a Q-switched operating mode and a fundamental mode structure; it should have a single pulse of 0.3 to 10 mJ, pulse duration of 4 n/sec, and 1 to 3 pulses per burst. The spot size should be 10 μm, and the cone angle – 16°. A single pulse should be at 1-2 Hz, and a burst should be at 1 Hz.

2. Selected energy, shot selection, power output, and shot counter - should all be displayed and controlled by the unit.

3. The laser should have a joystick beam actuator.

4. A compatible slit lamp should be used with magnification up to 25× and a working distance of 1,000 mm.

5. Each unit should have an automatic calibration system and the following accessories: contact lens, co-observation, a television with 35 mm adapter, a head restraint system, and a tonometer. An excimer laser should have a wavelength of 193 nm, 0-3 W of power output at tissue, 10 mJ per pulse, and an energy density of 150- 200 mJ/cm2, it should have both continuous and pulsed delivery modes, a beam diameter of 1 to 5 mm, a pulse repetition rate of 10 to 200 Hz, and a pulse duration of 10 to 15nsec.

6. Buyers should expect a unit with a high precision spot delivery system, a computer system, halogen gas cylinders, and 24 months of halogen source useful life.

7. A diode laser should have a power output on tissue of 1 W, both continuous and pulsed delivery modes, a pulse repetition rate 10 Hz, and pulse duration of 50 msec to continuous.

8. There are units requiring higher voltages and greater current capacity than those available from a standard outlet. If a unit needs an external water source, facilities should locate it above the first floor of an older building, and they may need a booster pump to provide adequate water pressure for cooling.

9. Facilities are encouraged to submit requests for proposal to several suppliers. They should discuss the important issue of prospective servicing.

10. Buyers should evaluate whether the laser is adaptable for other types of therapy for which they have a need.

Questions for the Seller

Before you purchase your Ophthalmic Retinal Laser, we recommend you ask the seller the following questions:

Previous Usage

• What was the first operation date of the equipment?
• Is there a log book for the equipment?
• How much was the last laser element in use (number of pulses)?
• Does the beam shutter function properly?
• Is the optical path aligned and clean (mirrors, end fiber optics etc.)?
• Is the laser output (Energy/Power) according to the manufacturer specification?
• Is the laser beam aligned with the visual pointing beam? Is the timing device which controls the exposure accurate?
• Does the cooling system function properly? Is the system labeling (including the laser class) clear?
• What is the general condition (external) of the system? Was the equipment ever repaired?
• Was the original laser element ever replaced?