Abstract
Abstract: :
Purpose:To study the effect of verteporfin photodynamic therapy (PDT) on retinal morphology in subfoveal choroidal neovascularisation (CNV) secondary to age–related macular degeneration (AMD) using optical coherence tomography (OCT) Materials and methods:Patients with subfoveal predominantly classic CNV, with or without occult, secondary to AMD were enrolled into a longitudinal prospective cohort study. Treatment comprised TAP protocol PDT and was applied at baseline and, where lesions were judged active, at follow–up 3 monthly examinations. Observations at each visit comprised: full refraction protocol logMAR visual acuity (VA) recorded as letters read on an ETDRS chart at 1 metre, slit lamp biomicroscopy, stereoscopic fluorescein angiography (FA) and serial OCT. Single horizontal line scan and fast macular OCT3 scans (model 3000, Zeiss–Humphrey, USA) passing through the fovea were analysed using the terminology presented by us at ARVO 2003 (IOVS 2003;44: E–abstract #4867): neuro–retinal foveal thickness (NFT), bilaminar foveal thickness (BFT) and outer high reflectivity band thickness (OHRBT). Paired sample t–test was used to investigate the change in OCT measurements from baseline. Results:71 eyes of 64 patients were recruited: 62 classic, no occult and 9 predominantly classic with occult. Mean absolute OCT measurements (±95% confidence limits) and VA with mean change (δ) from baseline after PDT are summarised in the table.
There was a restoration to a near normal foveal contour compared to baseline with the maximal reduction of the mean retinal thickness by month 3. We could not demonstrate a statistically significant association between VA and any OCT parameter. Conclusions:Longitudinal study suggests that PDT is associated with decreasing NFT and BFT on OCT3 while thickness of CNV/RPE complex appears to remain stable. OCT offers new insights into changes in retinal pathophysiology following PDT for CNV.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • choroid: neovascularization • age–related macular degeneration