Abstract
Purpose: :
The PHP multicenter clinical trial has demonstrate the good specificity (88%) and sensitivity (82%) in detecting recent onset CNV and differentiating them from intermediate AMD. The purpose of this study was to determine the clinical characteristics of CNV cases that did not demonstrate a significant visual field defect on the PHP (false negative cases) and to determine the clinical significance of these findings.
Methods: :
A comparison of age, lesion size, location and type, days with symptoms, visual acuity, existence of blood, laser and blocked fluorescence was made between the eyes with true positive PHP (n=53) and false negative PHP (n=12).
Results: :
Two parameters showed a difference: 1. the lack of a classic component; 2. a relatively good visual acuity. All eyes with a classical component of the CNV were detected by the PHP. All eyes which were not detected by the PHP were occult lesions, and were more likely to have a good visual acuity (0=0.05).
Conclusions: :
False negative PHP result may occur in cases with occult lesions only, mainly with a relatively good visual acuity. Treatment in such cases of in not warranted until disease progressed and the visual acuity declined to < 20/50.
Keywords: choroid: neovascularization • age-related macular degeneration • perimetry