Macular microcirculation blood flow in patients with age related macular degeneration treated with photodynamic therapy and transpupillary thermotherapy

Purpose
To assess the macular retinal and choroidal microcirculation blood flow in patients with exudative age related macular degeneration before and after photodynamic therapy (PDT) or transpupillary thermotherapy (TTT) with Doppler laser scanning (HRF – Heidelberg retinal flowmeter).

Material and methods
Thirty patients with exudative age-related macular degeneration were included in a prospective study. The diagnosis was established based on ophthalmic examination and fluorescein angiography results. In all cases the subfoveal choroidal neovascularization (CNV) was present. Control group consists of the fellow eyes with early stage of AMD (19 eyes) or with disciform scar (11 eyes). In 15 eyes with active CNV PDT was performed and in remaining 15 – TTT. In all cases the macular blood flow was measured with Heidelberg retina flowmeter (HRF) before therapy and then 1 week, 4 weeks and 10-12 weeks after treatment.

Results
At the baseline examination in a group of eyes with active CNV the mean values of macular blood flow were significantly higher comparing to the fellow eyes and reached respectively: 678.6 ± 125.0 AU and 298.4 ± 79.2 AU (p=0.001). Four weeks after treatment all eyes showed the reduction of macular blood flow comparing to the baseline values (p=0.001). Ten to twelve weeks after laser therapy in all cases the increased macular blood flow was detected comparing to the previous examination (p=0.01). During the follow-up period the macular blood flow in the fellow eyes were significantly lower than in treated eyes.

Conclusions
The measurement of macular blood flow using Doppler scanning laser (HRF – Heidelberg retinal flowmeter) may act as a non-invasive and useful diagnostic tool in assessment of CNV activity in patients with exudative age-related degeneration before and after PDT or TTT.