Binocular Indirect Laser Treatment
What is binocular indirect laser treatment?
Binocular indirect laser treatment is phototherapy administered using a binocular indirect ophthalmoscope. A beam of infra-red 'light' or green light is directed at the tumor, to induce burns.
How is it administered?
- This treatment is administered under general anesthesia in babies and under local or general anesthesia in adults.
- A 0.5 - 1 mm-diameter beam of laser is directed through the pupil at the tumor, by means of binocular indirect ophthalmoscopy, with the patient lying supine (i.e., face up) on the operating table.
- Each burn lasts for 0.5 to 1.0 seconds.
- The entire tumor is treated, together with surrounding apparently-healthy choroid.
- The type of laser (i.e., infra-red or green) is selected according to the amount of pigment under the tumor.
What are the indications?
- Small retinoblastomas, located towards the back of the eye (i.e., 'equatorial or post-equatorial').
- Some retinal hemangioblastomas.
What are the contra-indications?
- Small pupil size, because of the risk of iris damage.
- Tumor location in the peripheral/anterior retina, because of the risk of iris damage.
- Cataract and other opacities preventing a clear view of the tumor.
- Excessive tumor size.
What are the intra-operative complications?
- Loss of vision if the fovea or optic nerve is treated.
- Blockage of retinal vessels by excessive laser power.
- Seeding of retinoblastoma cells if an excessive power is used.
- Failure to destroy the entire tumor is insufficient power is applied or if not all the tumor is treated.
What are the post-operative complications?
- Local tumor recurrence if the tumor survives the laser treatment
- Loss of vision as a result of blocked veins or damage to optic nerve or retina.
- Adhesions between the iris and lens (i.e., 'posterior synechiae') if iris burns occur.
- Cataract if iris burns occur.