Abstract
Purpose: :
To evaluate a new modality for treatment of recalcitrant choroidal neovascular in peripapillary region.
Methods: :
We used an infrared laser (810nm) in oscillatory thermotherapy (OTT) mode and Indocyanine green (ICG) photosensitizer as (I-OTT) plus intravitreal bevacizumab/dexamethasone in refractory peripapillary CNV.Four patient’s eyes with recalitrant peripapillary CNV were prospectively treated with I-OTT. Clinical exam, fundus photography, OCT and IVFA were performed at baseline and postoperatively. The laser spot size was approximately half the lesion size. Parameters were determined with an extramacular test spot in a non-oscillating mode using the maximum power tolerable without causing pain for >10-15 seconds, then applied in oscillatory/rotatory mode over the entire lesion. The laser exposure time was 90-120 seconds in thermal mode, pre-ICG infusion and 90-160 seconds post-ICG infusion. Bevacizumab (1.25mg) / dexamethasone (1000µg) were immediately injected. I-OTT could be repeated, as needed clinically.
Results: :
Mean follow up was 10.25 months (range from 5-15 months). Mean energy level was 325mW (range from 200-500mW) in oscillatory mode (2-3 Herz/sec.)for pre and post ICG infusion. The spot size was 1.2mm in three patients and 2 mm in one patient. An ICG concentration of 1mg/kg (75 mg/patient ) was used. All patients required a single treatment session. V.A. improved in one patient from 20/60 to 20/30 and remained the same in the other 3 patients (20/20, 20/40 and 20/400). At the final exam, there was no evidence of clinical or angiographic activity of the CNVs in any eye, no side effects related to the treatment and no eyes needed retreatment .
Conclusions: :
I-OTT, a new modality for the treatment of recalcitrant peripapillary CNV, has the potential to treat CNV in wet ARMD and other conditions. This technique may reduce thermal side effects of TTT and may eliminate or reduce the need for frequent intravitreal treatment, as is currently practiced. The effect of I-OTT is postulated to be a synergistic effect of thermal energy combined with a weak photosensitizer (ICG) applied in an individualized manner that minimizes thermal damage to the retina and choroidal tissue. Additional anti-VEGF pharmocotherapy enhances the effect of I-OTT on abnormal new vessels.
Keywords: age-related macular degeneration • laser • neovascularization