Resorption of Posterior Pole Drusen Following Focalargon Laser Photocoagulation Applied Anterior to the Equator

Abstract

Abstract: : Purpose: To determine whether argon retinal laser photocoagulation (ARLP) applied in a focal pattern anterior to the equator can significantly reduce both discrete and confluent drusen at the posterior pole. Methods: We have previously reported (IOVS 2002 43: E–Abstract 1209) a reduction of 25% over three years in macular large drusen after ARLP in one patient whose fellow eye already had CNV. Based on this finding we undertook an inter–institutional, prospective, observer masked controlled trial of ARLP in six patients with bilateral soft drusen without CNV and normal visual acuity. Each patient had one eye randomized to treatment; the fellow eye was the control. We measured drusen areas as a percentage of the 6000 micron region in a masked fashion. We have developed a reproducible digital technique that employs background leveling using a mathematical model to segment large drusen in fundus photographs with an accuracy of 5% with respect to manual stereo fundus grading [IOVS 45 E–2415, 2004]. A difference of more than 5% in absolute drusen load with respect to the previous visit was chosen as significant. Results:The six month results for six patients showed that in two treated eyes there was a reduction of drusen area (39 % to 27 % and 23 % to 17 %), whereas in all other eyes there was no significant change. In both treated and control eyes no complications were noted. Conclusions: ARLP appears promising and merits further study. We plan to continue monitoring these patients and to enroll further patients for this treatment.

Keywords: drusen • laser • imaging/image analysis: clinical