SCANNING LASER MICROPERIMETRY OF MACULAR DISEASES

Background Scanning laser microperimetry allows focal sensitivity testing of any localization of the retina under direct visual control. Physiological or involuntary fixation shifts can be corrected by manual fundus-tracking. Methods For static fundus-controlled microperimetry we used a confocal scanning laser ophthalmoscope equipped with a helium-neon laser as light source for background illumination and for generating the stimuli by acousto-optic modulation. Fundus imaging was achieved by an infrared diode laser scanning synchronous with the helium-neon laser. In comparison computerized static projection perimetry was performed using the Humphrey Field Analyser, program 10-2. Results On the basis of four exemplary cases (macular hole, juxtafoveal pigment epithelium atrophy, subretinal neovascularization secondary to age-related macular degeneration) it is shown that extension and depth of scotomas can be recorded more precisely with scanning laser microperimetry than with conventional projection perimetry. Microscotomas can be detected. By using infrared laser for fundus imaging choroidal structures such as subretinal neovascular membranes can be visualized, even when moderate intra- or subretinal hemorrhages secondary to age-related macular degeneration are present. Thus focal sensitivity testing of the retina overlying neovascular membranes is possible. Simultaneous registration of fixation allows precise localization of the fixation point and its relationship to neovascular membranes. Conclusion The advantage of fundus-controlled microperimetry is a precise examination of the impact of morphological changes on psychophysical functions of the macula. Due to its simultaneous registration of fixation fundus-oriented microperimetry is a very informative aid in the indication of laser therapy and the selection of different laser procedures in the treatment of subretinal neovascularizations.