Abstract
Abstract: :
Purpose: Due to the fixed circular form of current PDT laser spots, inclusion of the fovea in the treated area cannot be avoided in most macular CNV treatments. The advantages of masks introduced in the PDT laser beam to spare the fovea in suitable cases was investigated. Methods: Circular masks corresponding to 400, 500 and 600 microns in diameter on the retina were introduced in the laser beam of the Zeiss Visulas 690S, PDT laser. The masks can be moved in the area of the infrared laser spot. Forty patients suffering from AMD (15 males and 25 females, age range 65 to 85 years) for whom CNV treatment was advised were treated with the mask positioned suitably to protect the fovea. The size and the position of the mask in the laser spot were selected in order to achieve the best topographic relationship between the area to be treated and the area to be protected. For each patient a complete ophthalmological examination with ETDRS visual acuity testing and fluorescein and indocyanine green dynamic scanning laser angiography (Heidelberg Retinal Angiograph, Heidelberg Eng., Ottobrunn; Germany) were performed before treatment and during a six month follow-up period. Results: The fovea-masking effect was clearly evident in most patients in post-treatment angiographies. Visual acuity improved in 80% of patients, was stable in 16% and decreased in 4% at the end of the follow-up period. CNV was closed post treatment in 78%, reduced in 13% and unchanged in 9%. Seventy per cent of patients needed retreatment which was performed according to the TAP and VIP protocols. Conclusions: The introduction of a mask in the laser beam to protect the fovea may be advised in selected cases of CNV, in which protection of the fovea cannot compromise the completeness of treatment. Due to the frequent occurrence of this instance in clinical practice, an RCT aimed at investigating this issue is advisable.
Keywords: photodynamic therapy • choroid: neovascularization • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S