Archived Policies - Other

Transpupillary Thermotherapy (TTT)


Effective Date:11-15-2007

End Date:11-30-2009


Transpupillary thermotherapy (TTT) is considered experimental, investigational and unproven as a treatment of choroidal neovascularization associated with age related macular degeneration.


Choroidal neovascularization (CNV) is a common cause of adult-onset blindness, most commonly associated with age-related macular degeneration (ARMD).  While laser photocoagulation has been used to treat CNV, patients with subfoveal lesions are generally not candidates for this treatment due to the risk of an immediate reduction in central vision, outweighing any treatment advantage.  Recently photodynamic therapy has been used with success in treating subfoveal CNV.  The treatment has shown the greatest success in treating patients with classic CNV (as opposed to occult CNV), as defined angiographically.  There is ongoing research interest in the use of transpupillary thermotherapy to treat subfoveal CNV with an occult angiographic pattern.

Transpupillary thermotherapy (TTT) is a technique in which heat is delivered to the choroid and retinal pigment epithelium through the pupil using a modified diode laser.  This laser technique contrasts with the laser used in standard photocoagulation therapy in that TTT uses a lower power laser for more prolonged periods of time and is designed to gently heat the choroidal lesion, thus limiting damage to the overlying retinal pigment epithelium.

While photodynamic therapy as a treatment of CNV also involves the use of a laser, in this application, the laser is a nonthermal laser designed to activate Verteporfin, the photosensitizing agent.


There are minimal published data regarding TTT.  Reichel and colleagues reported on a case series of 16 eyes in 15 patients who presented with occult subfoveal choroidal neovascularization secondary to age-related macular degeneration.  Three eyes showed a two or more line improvement in visual acuity over a period of 6 to 25 months.  Visual acuity remained stable in nine treated eyes.  The remaining four eyes showed a decline in visual acuity.  

Newson and colleagues reported on a case series of 44 eyes in 42 patients consisting of 12 eyes with classic CNV and 32 eyes with occult CNV.  The mean follow-up was six months.  The mean change in vision in those with classic and occult CNV was –0.75 and –0.66 Snellen lines, respectively.

The TTT4CNV Study is a nationwide study involving 22 centers that was started in March 2000. A total of 336 patients with symptomatic occult CNV that shows signs of exudation are being recruited.  Two-thirds of eyes will be treated and one-third will receive sham treatment.  Patients will be followed up for two years.

One prospective nonrandomized study of 21 eyes with idiopathic CNV reported 81% of patients treated with TTT were improved or stabilized at a mean of 5.1 months’ follow-up.  Three other nonrandomized studies of TTT in eyes with CNV related to ARMD were reported.  Nagpal and colleagues reported on TTT for CNV in 160 eyes (99 classic and 61 occult) of patients of Indian descent.  The authors reported in classic CNV, 29.3% improved, 39.4% stabilized, and 31.3% deteriorated at 12 months’ follow-up.  In occult CNV, 19.6% improved, 57.4% stabilized, and 22.9% deteriorated.  Nagpal and colleagues concluded that there was effectiveness with TTT in Indian eyes, which responded to lower energy levels than did Caucasian eyes in their experience. In a study by Thach and colleagues, 69 eyes with occult CNV were treated with TTT.  After a minimum of six months’ follow-up, 71% of patients improved or stabilized.  Finally, in the Algvere study of TTT in predominately occult CNV, 8% improved, 40.7% stabilized, and 51.3% deteriorated after 12 months’ follow-up.  Algvere and colleagues reported minimally classic CNV responded poorly to TTT.  While there appears to be some improvement or stabilization in occult CNV in these studies, further study is needed to demonstrate that improvements in health outcomes occur with acceptable levels of adverse effects with TTT over the natural course of the disease.

In a presentation at the American Academy of Ophthalmology meeting in October 2004, in New Orleans, Iridex Corporation announced preliminary results of the TTT4CNV study.  Iridex reported preliminary results did not show TTT for CNV resulted in significant benefit over sham treatment.  Only 47% of 303 patients who received TTT for CNV had modest or severe vision loss after two years, compared with 43% in those who received sham treatment.  Further analysis of the data will be performed, according to Iridex Chief Executive Theodore Boutacoff.

An October 2005 Blue Cross Blue Shield Association Technical Evaluation Center Special Report on the treatment of ARMD supports the conclusions given above noting TTT, when used alone, has not been efficacious.  A trial combining triamcinolone with TTT is currently in progress.

A search of the MEDLINE database for the period of January 2000 through September 2007 found no evidence to support a change in the policy statement.  TTT is being studied outside of the U.S. for patients with occult CNV who are not candidates for phototherapy. Two small randomized trials (28 and 25 patients) reported no benefit of TTT in preventing further visual loss in patients with occult CNV, while a case series reported macular burn as a complication of TTT in 8.6% of 35 patients available for follow-up.  One randomized (not blinded) study of 26 patients did not find a statistically significant improvement for combination treatment with triamcinolone and TTT in comparison with TTT alone.


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Medicare Coverage:

The information contained in this section is for informational purposes only.  HCSC makes no representation as to the accuracy of this information.  It is not to be used for claims adjudication for HCSC Plans.

Medicare (CMS) does not have a national coverage position.  Coverage may be subject to local carrier discretion.

A national coverage position for Medicare may have been developed or changed since this medical policy document was written.  See Medicare's National Coverage at <>.


Reichel, E., Berrocal, A.M., et al.  Transpupillary thermotherapy of occult subfoveal choroidal neovascularization in patients with age-related macular degeneration.  Ophthalmology (1999) 106(10):1908-14.

Newson, R.S., McAlister, J.C., et al.  Transpupillary thermotherapy (TTT) for the treatment of choroidal neovascularization.  British Journal of Ophthalmology (2001) 85(2):173-8.

Nagpal, M., Nagpal, K., et al.  Transpupillary thermotherapy for treatment of choroidal neovascularization secondary to age-related macular degeneration in Indian eyes.  Indian Journal of Ophthalmology (2003) 51(3):243-50.

Thach, A.B., Sipperley, J.O., et al.  Large-spot size transpupillary thermotherapy for the treatment of occult choroidal neovascularization associated with age-related macular degeneration.  Archives of Ophthalmology (2003) 121(6):817-20.

Algvere, P.V., Libert, C., et al.  Transpupillary thermotherapy of predominantly occult choroidal neovascularization in age-related macular degeneration with 12 months follow-up.  Acta Ophthalmologica Scandinavica (2003 April) 81(2):110-7.

Kumar, A., and G. Prakash.  Transpupillary thermotherapy for idiopathic subfoveal choroidal neovascularization.  Acta Ophthalmologica Scandinavica (2004) 82(2):205-8.

Current and evolving strategies in the treatment of age-related macular degeneration.  Chicago, Illinois:  Blue Cross Blue Shield Association - Technology Evaluation Center Assessment Program Special Report (2005) Tab 11.

Gustavsson, C., and E. Agardh.  Transpupillary thermotherapy for occult subfoveal choroidal neovascularization: a 1-year, prospective randomized pilot study.  Acta Ophthalmologica Scandinavica (2005) 83(2):148-53.

Agurto-Rivera, R., Diaz-Rubio, J., et al.  Intravitreal triamcinolone with transpupillary therapy for subfoveal choroidal neovascularization in age related macular degeneration.  A randomized controlled pilot study [ISRCTN74123635].  BMC Ophthalmology (2005) 5:27.

Rougier, M.B., Francois, L., et al.  Complications and lack of benefit after transpupillary thermotherapy for occult choroidal neovascularization: 1-year results.  Retina (2005) 25(6):784-8.

Stolba, U., Krebs, I., et al.  Long term results after transpupillary thermotherapy in eyes with occult choroidal neovascularisation associated with age related macular degeneration:  a prospective trial.  British Journal of Ophthalmology (2006 February) 90(2):158-61.

Tranos, P., Peters, N.M., et al.  Visual function following transpupillary thermotherapy with adjusted laser parameters for the treatment of exudative age-related macular degeneration:  a pilot study.  Clinical Experiment Ophthalmology (2006 April) 34(3):226-32.

Myint, K., Armbrecht, A.M., et al.  Transpupillary thermotherapy for the treatment of occult CNV in age-related macular degeneration: a prospective randomized controlled pilot study.  Acta Ophthalmologica Scandinavica (2006 June) 84(3):328-32.

Transpupillary Thermotherapy for Treatment of Choroidal Neovascularization.  Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2007 April) Vision 9.03.10.

Tewari, H.K., Prakash, G., et al.  A pilot trial for comparison of photodynamic therapy and transpupillary thermotherapy for the management of classic subfoveal choroidal neovascularization secondary to age-related macular degeneration.  Indian Journal of Ophthalmology (2007 July – August) 55(4):277-81.

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