PHOTODYNAMIC EFFECTS ON RETINAL OXYGEN SATURATION, BLOOD FLOW, AND ELECTROPHYSIOLOGICAL FUNCTION IN PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

Abstract

To evaluate the effect of photodynamic therapy (PDT) on retinal functions, such as oxygen saturation, blood flow, and electrophysiological function using Fourier transform-based spectral retinal imaging (SRI), Heidelberg retinal flowmeter (HRF), and multifocal electroretinogram (mfERG). This was a prospective interventional case series. Twenty-two patients with age-related macular degeneration (AMD) with unilateral choroidal neovascularization (CNV) were examined using SRI, HRF, and mfERG before and 1 week and 1 month after PDT. Eleven fellow eyes without CNV and 11 control eyes of 11 age-matched healthy volunteers were also investigated. Eleven of 22 patients with neovascular AMD were retreated using verteporfin PDT and examined using a protocol similar to the one used for the first treatment. Oxygen saturation levels in the macula of eyes with neovascular AMD were significantly higher than those in normal control eyes (P = 0.026) but were not significantly higher in eyes with nonneovascular AMD. Oxygen saturation levels decreased 1 week after a single treatment (P = 4.59 x 10(-3)) and retreatment (P = 0.0134) and recovered to baseline levels at 1 month follow-up (P > 0.05). HRF demonstrated reduced mean blood flow at 1 week after single treatment (P = 9.22 x 10(-4)) and retreatment (P = 0.0307). One month after PDT, mean blood flow tended to show recovery. There was a similar decrease in mfERG amplitude 1 week after treatment, but the logarithm of minimum angular resolution (logMAR) vision was stable or improved throughout follow-up. Oxygen saturation levels, mean blood flow, and mfERG amplitude decreased 1 week after PDT treatment in both single treatment and retreatment groups. Although logMAR vision is stable or improved, our data showed transient functional deterioration in the retina after PDT treatment.