Aim: To compare the efficacy of low dose transpupillary thermotherapy (TTT) and verteporfin photodynamic therapy (PDT) in patients with occult neovascular age-related macular degeneration (AMD).
Methods: Patients were randomized to receive either low dose TTT (136 mW/mm) (and sham PDT) (n = 52) or PDT (and sham TTT) (n = 46) with retreatment if leakage was documented by fluorescein angiography. At baseline and at every follow up, best corrected visual acuity (BCVA) was measured with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, lesion size on fluorescein angiography and foveal thickness with optical coherence tomography. The primary outcome measure was the proportion of patients who lost < 15 letters at 12 months follow up. Secondary outcome measures included the proportion of patients who gained => 0 letters, the change in mean lesion size and the change in foveal thickness at 12 months follow up.
Results: The percent of patients losing fewer than 15 letters at 12 months was 75.0% in the TTT group and 73.9% in the PDT group (p>0.05). The percent of patients with preserved or improved BCVA was 36.5% in the TTT group versus 23.9% in the PDT group (p>0.05). The mean decrease in foveal thickness was 15% for TTT and 24% (p>0.05) for PDT treated patients and the mean increase in total lesion area was -0.7% and -1.1% (p>0.05), respectively.
Conclusion: In this prospective, randomized trial low dose TTT and PDT appeared to be equally efficient at stabilizing visual acuity in patients with occult neovascular AMD. Low dose TTT may be considered as an alternative to PDT in this set of patients and also as an adjuvant to pharmacotherapy.