الفهرس 
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Abstract
Lasers are used extensively in ophthalmology. With advances in laser technology, lasers became critical tools in the management of retinal vascular diseases and retinal breaks. More recently, lasers have been employed in the management of intraocular tumors.
Transpupillary thermotherapy (TTT) delivers heats to the target tissues in the form of a laser beam using a lower power for a prolonged period to limit damage to surrounding tissues. This technique contrasts with the laser used in conventional photocoagulation therapy in that the conventional laser treatment uses a high power for a short period of time, causing tissue damage.
The present essay aims to discuss the indications and technique of TTT with emphasis on the recent trends in this issue.
Transpupillary thermotherapy (TTT) was introduced for managing choroidal melanoma in 1994 and was found to have fewer complications, greater penetration, and improved tumor destruction compared to laser photocoagulation.
TTT has been investigated for use in circumscribed choroidal hemangiomas, as it may avoid complications associated with laser photocoagulation (cataract, bleeding, secondary choroidal neovascularization, and retinal ablation resulting in visual field defects) and radiotherapy (cataract, radiation optic neuropathy, and maculopathy). Multiple studies have shown resolution of subretinal fluid. Additionally, TTT induces tumor regression, while also preserving and sometimes improving vision.
Several studies have proved the efficacy of TTT in the primary treatment of small retinoblastomas, with complete tumor regression in 86 and 92% of small tumors.
Central serous chorioretinopathy (CSC) has been traditionally treated with laser photocoagulation. Although recent articles have reported that TTT can be also utilized for the treatment of CSC, it was thought that TTT utilizing a lower temperature than that of conventional laser photocoagulation might minimize permanent retinal and choroidal damage.
Pathologic myopia is one of the leading causes of visual loss in the world. Pathologic myopia is associated with progressive elongation of the eyeball that may be accompanied by degenerative changes in the sclera, choroid, Bruch’s membrane, retinal pigment epithelium (RPE), and neural retina. These changes include geographic atrophy of the RPE and choroid, lacquer cracks in Bruch’s membrane, subretinal hemorrhage, and cho¬roidal neovascularization.
Transpupillary thermotherapy has been advo¬cated for the treatment of choroidal neovasculariza¬tion.
Age-related macular degeneration (AMD) is the leading cause of irreversible vision impairment in developed countries. Although the exudative form accounts for only 20% of all AMD patients, development of choroidal neovascular membrane (CNV) is responsible for almost 90% of severe visual loss secondary to AMD. TTT was performed on patients with CNV using a diode laser (810 nm) for 60 s in a subthreshold manner.
Angioid streaks are breaks or dehiscences within the collagen or elastin laminae of an abnormally thick, brittle, and calcified Bruch membrane. The effect of transpupillary thermotherapy (TTT) on choroidal neovascularization (CNV) secondary to angioid streaks was investigated. concluded that TTT may decrease the activity of CNVs secondary to angioid streaks in the short term, but retreatment may be necessary with unfavorable results.
Retinopathy of prematurity (ROP) remains one of the most important causes of childhood blindness. Using TTT, had complete regression after laser and none ended up having unfavorable outcome.
Premacular hemorrhage resulting from proliferative diabetic retinopathy, a ruptured macroaneurysm, Valsalva retinopathy, or other vascular disorders usually causes a profound loss of vision. Using TTT, gradual clearance of the hemorrhage and the asteroid bodies from the vitreous was revealed on follow-up funduscopy.