Types of Ophthalmic Lasers and Where Each One Fits

How ophthalmic lasers differ

Three properties define a laser's effect. Wavelength decides what tissue absorbs the light: pigment, haemoglobin or water. Pulse length decides whether the effect is thermal (long pulses coagulating tissue) or mechanical (nanosecond pulses disrupting tissue). Spot size and energy decide how much tissue is affected. Together they explain why one clinic often needs several lasers rather than a single universal device.

Delivery is the fourth variable. Most clinic lasers are coupled to a slit lamp, such as the PCL5 platform from A.R.C. Laser; others use an indirect ophthalmoscope or a probe in surgery. The treatment decision always belongs to the ophthalmologist, and this page does not give clinical advice.

Nd:YAG laser (1064 nm): photodisruption

The Nd:YAG laser at 1064 nm is used for photodisruption, with very short nanosecond pulses that create a small plasma effect at the focus. Typical anterior-segment uses include posterior capsulotomy after cataract surgery and iridotomy in angle-closure glaucoma. The A.R.C. Laser Q-Las sets energy from 0.5 to 10 mJ, offers burst mode of 1, 2 or 3 pulses, pulse length of 4 ns and repetition up to 10 Hz. Learn more in what is YAG laser in ophthalmology.

YAG is a cold, mechanical effect, so it differs from thermal coagulators. Clinics that treat cataract patients commonly keep one available.

SLT laser (532 nm) and green and other photocoagulators

Selective laser trabeculoplasty uses a Q-switched, frequency-doubled Nd:YAG laser at 532 nm, as in the CITO 532, with pulse energy 0.2 to 2.0 mJ and a 400 µm spot. It is used in glaucoma services; see SLT laser for glaucoma. When people ask what green laser is in ophthalmology, they usually mean either this 532 nm laser or a 514 or 532 nm photocoagulator.

Photocoagulators for the retina use continuous or pulsed visible light to heat and coagulate tissue. The CLASSIC 514 is a 514 nm diode system with up to 1.2 W, 50 to 600 µm spots and single-pulse, gated and micropulse modes. Yellow 577 nm and other wavelengths also exist in the market. For the retina see retinal photocoagulation lasers.

• Nd:YAG 1064 nm: capsulotomy, iridotomy
• SLT 532 nm: trabeculoplasty in glaucoma services
• 514 nm photocoagulator: retinal treatment
• 810 nm diode: retina, glaucoma and DCR
• Nanosecond cataract laser: phaco-assist

Diode lasers (810 nm) and cataract lasers

The 810 nm diode laser is absorbed deeper than green and is used for retinal photocoagulation, transscleral cyclophotocoagulation and some oculoplastic uses. The FOX IV 810 is a 1.53 kg diode laser with 8 W output, battery or mains operation, a micropulse cyclophotocoagulation probe, and a 3 W power limit for glaucoma and retinal treatments.

Cataract lasers are a different category: femtosecond systems cut with ultrashort pulses, and excimer lasers sculpt the cornea for refractive surgery. A.R.C. Laser makes the CETUS NanoLaser, a 1064 nm, 5 ns laser that fragments the lens by photofragmentation and attaches to an existing phaco machine. Refractive femtosecond and excimer platforms are outside this range.

Which lasers does a new eye clinic need first

A general eye clinic often starts with a YAG laser and, depending on case mix, an SLT or a retinal photocoagulator. Combination units save space: the COBRA pairs SLT with YAG, and VARIO places two lasers on one table. See our slit lamp buying guide for platform choices and the ophthalmic laser buying guide for a general checklist.

Beckfinity supplies Q-Las, CITO 532, CLASSIC 514 and FOX IV 810 from A.R.C. Laser in the UAE. Contact our specialists to plan your service.