Novus Spectra
0642-543-01, Rev A, 12/02
88 Indications for Use
Diabetic neovascular retinopathy
Laser photocoagulation is often used to control diabetic
neovascularization. This condition is the proliferation of
blood vessels in the retina. These newly formed blood vessels
often have aneurysms that will, if left untreated, result in
vitreous hemorrhage.
The laser treatment for this condition is called pan-retinal
photocoagulation (PRP). During PRP, approximately 30% of
the area of the retina is treated by the laser. A large spot size
(100 to 400 µm) and approximately 400 to 800 mW of laser
power are normally used. The laser burns are applied in a
checker-board pattern with a space of untreated retina
between the laser burns approximately equal to the diameter
of the laser spot size. It may take as many as 1500 burns to treat an eye.
Therefore, the treatment is often given in more than one session. As a result of
the treatment, the treated retina dies in the region of the laser burn, and the
remaining untreated retinal tissues can be supplied with sufficient nutrients by
the existing blood supply, so the new blood vessels stop growing. The laser can
also be used to coagulate a blood vessel that is hemorrhaging.
The macula is usually avoided whenever possible while applying laser
treatment to the retina. However, if there is some condition of the macula that
requires laser therapy, yellow or red wavelengths are recommended.
Retinal detachments
The laser can sometimes be used to help control retinal
detachments. The desired effect is to form a chorioretinal scar
by making laser burns around the detached portion of the
retina. A row of burns approximately 200 to 500 µm in
diameter is made around the edges of the detachment. The
power used is usually about 250 to 450 mW, and the pulse
duration is 0.1 to 1.0 s. After the periphery of the detachment
has been secured, additional laser burns are made over the
detached portion of the retina.
Complications can occur because of traction caused by the
shrinkage or shortening of the vitreous strands. This traction
can cause the detachment to spread. Also, as in any retinal
laser treatment, if too much power is used a vitreal hemorrhage can result.
Summary of Contents for Novus Spectra
Page 1: ...Novus Spectra Solid State 532 nm Green Laser Operator Manual...
Page 6: ...6 Contents Novus Spectra 0642 543 01 Rev A 12 02...
Page 8: ...Novus Spectra 0642 543 01 Rev A 12 02 8 General Operation...
Page 40: ...Novus Spectra 0642 543 01 Rev A 12 02 40 General Operation...
Page 42: ...Novus Spectra 0642 543 01 Rev A 12 02 42 Maintenance...
Page 56: ...Novus Spectra 0642 543 01 Rev A 12 02 56 Safety and Regulatory...
Page 72: ...Novus Spectra 0642 543 01 Rev A 12 02 72 Indications for Use...
Page 110: ...Novus Spectra 0642 543 01 Rev A 12 02 110 Indications for Use...
