Fundus autofluorescence before and after photodynamic therapy for choroidal neovascularization secondary to age-related macular degeneration.

BACKGROUND AND OBJECTIVE: To describe fundus autofluorescence patterns in choroidal neovascularization secondary to age-related macular degeneration before and after photodynamic therapy (PDT). PATIENTS AND METHODS: Sixty-eight consecutive eyes were indicated for PDT after standard fluorescein angiography, which showed completely classic choroidal neovascularization (CNV) (n=52), occult with no classic CNV (n=7), and predominantly classic CNV (n=9). Standardized PDT was performed and patients were examined 2 to 3 months later. Angiography and autofluorescence measurements were performed again and compared with preoperative values. RESULTS: At baseline, autofluorescence was mainly decreased in areas of completely classic CNV (79%), but showed a regular or mottled pattern in occult CNV. A slightly increased (50%) or normal (50%) autofluorescence was seen at the rim of the classic lesions within the junctional zone. Membrane demarcation was improved (90%) in classic membranes 2 to 3 months after PDT. After PDT for occult membranes, a transformation into classic membranes with residual leakage and need for further PDT was observed (6 of 7 eyes), showing the described autofluorescence patterns. For the mixed type of CNV, both described patterns of autofluorescence distribution were found. CONCLUSION: Especially classic CNVs reveal distinct characteristics of significantly decreased autofluorescence, presumably due to their localization above the retinal pigment epithelium level, leading to blockage of autofluorescence. Autofluorescence patterns after PDT included enhanced demarcation of the membrane, suggesting reactive retinal pigment epithelial changes. Autofluorescence might be an interesting tool to distinguish noninvasively between classic and occult CNV in age-related macular degeneration and to monitor changes after PDT.

Evaluation of retinal function and flicker light-induced retinal vascular response in normotensive patients with diabetes without retinopathy.

PURPOSE: To correlate retinal function with vascular response to flicker light in normotensive patients with diabetes without diabetic retinopathy (DR). METHODS: Twenty-eight normotensive patients with diabetes (11 with type 1, 17 with type 2) without DR and 28 sex- and age-matched healthy control subjects underwent color vision and contrast sensitivity testing, pattern, full-field, and multifocal electroretinography, and evaluation of the vascular response to flicker light with the dynamic vessel analyzer. RESULTS: In the patients with diabetes, electroretinogram (ERG) pattern responses, b-wave in the scotopic bright flash ERG, a-wave and b-wave in the photopic single-flash ERG, and oscillatory potential responses were significantly impaired compared with those in control subjects. Vascular response to flicker light was also impaired in patients with diabetes compared with controls. In the whole population, correlations were found between flicker light-induced arterial retinal vasodilation and the amplitude and implicit time of the N95 wave of pattern ERG (r = -0.27, P = 0.047 and r = -0.35, P = 0.008, respectively), the b-wave implicit time of rod ERG (r = -0.36; P = 0.01) and the oscillatory potentials (r = 0.4; P = 0.003), suggesting that impairment of the vascular response to flicker light may reflect inner retinal neural impairment. However, no correlation between these factors was found when only patients with diabetes were considered. CONCLUSIONS: In patients with diabetes, neural and neurovascular dysfunctions both precede the onset of clinically detectable DR. To which extent these abnormalities are related to each other remains to be determined. (ClinicalTrials.gov number, NCT00839150.)