Abstract
Abstract: :
Purpose: Age–related macular degeneration (ARMD) is the leading cause of blindness in people older than 65 years of age. Rapid loss of vision especially occurs in cases with choroidal neovascularization. Early detection of ARMD and timely treatment is mandatory. We prospectively studied the results of two diagnostic self tests for early detection of metamorphopsia and scotoma, PHP test and Amsler grid test, in different stages of ARMD. Methods: Patients with ARMD and best corrected visual acuity of 0.2 or better (Snellen charts) were examined with a standardized protocol, including supervised Amsler grid examination and PHP, a new device for macular metamorphopsia or scotoma measurement, based on the hyperacuity phenomenon in the central 14º of the visual field.The stages of ARMD were independently graded in a masked fashion by funduscopy, stereoscopic macula color photographs, and fluorescein angiography. The patients were subdivided into 3 nonneovascular groups (early, late (RPE atrophy > 175 µm) and geographic atrophy), and a neovascular group (classic and occult CNV). Results: 97 patients, age ranging from 55 to 87 years (median 76 years), were included in the study. Best corrected visual acuity ranged from 6/24 to 6/6 with a median of 6/12. 68 were diagnosed as nonneovascular ARMD. Twenty–four eyes had early ARMD (7 were tested positive by the PHP test and 6 by the Amsler grid test), and 31 late ARMD (positive: PHP test 15, Amsler grid test 17). The group with geographic atrophy consisted of 13 eyes (positive: PHP test 11, Amsler grid test 8). Twenty–nine patients presented with neovascular ARMD (positive: PHP test 26, Amsler grid test 25). Conclusions: The PHP and Amsler grid tests revealed comparable results detecting metamorphopsia and scotoma in the early ARMD (29% vs 25%), late ARMD (48% vs 55%), and neovascular ARMD (90% vs 86%). However the PHP test more often revealed disease related functional changes in the group of geographic atrophy (85% vs 62 %). This implicates that the PHP and Amsler grid self tests are useful tools for detection of ARMD and that PHP is superior in the group of geographic atrophy.
Keywords: age-related macular degeneration