In patients with acute central serous retinopathy (CSR), evaluation of visual acuity alone may not represent visual function. In patients with acute CSR, visual function may be disturbed by localized scotomas, distortion, and waviness. For the assessment of localized light sensitivity and stability of fixation, patients with CSR were evaluated by fundus perimetry with a scanning laser ophthalmoscope (SLO 101, Rodenstock Instruments). In all, 21 patients with acute CSR and 19 healthy volunteers were included in the study. Diagnosis of CSR was established by ophthalmoscopy and digital video fluorescein angiography. All patients and volunteers underwent static suprathreshold perimetry with the SLO. Light sensitivity was quantified by presenting stimuli with different light intensities (intensity, 0-27.9 dB above background; size, Goldmann III; wavelength, 633 nm) using an automatic staircase strategy. Stimuli were presented with simultaneous real-time monitoring of the retina. Fixation stability was quantified by measuring the area encompassing 75% of all points of fixation. Light sensitivity was 18-20 dB in affected areas, whereas in healthy eyes and outside the affected area, values of 22-24 dB were obtained. Fixation stability was significantly decreased in the affected eye as compared with normal eyes (33 +/- 12 versus 21 +/- 4 min of arc; P < 0.01). Static perimetry with an SLO is a useful technique for the assessment of localized light sensitivity and fixation stability in patients with macular disease. This technique could provide helpful information in the management of CSR.