Localized scotomata detected with temporal modulation perimetry in centralserous chorioretinopathy

Aim: Flicker deficits have been reported in various maculopathies, includin g age-related macular degeneration. We test whether flicker losses exist in patients with central serous chorioretinopathy (CSC) and whether the size and flicker frequency of the target is important in detecting such losses. Methods: We examined four CSC patients with temporal modulation (flicker pe rception) perimetry using the Medmont auto-flicker module (Medmont Pty Ltd, Melbourne, Vie. Australia), as well as static perimetry and colour vision. One case was examined using sophisticated laboratory equipment to precisel y measure their temporal contrast sensitivity function (temporal CSF or de Lange curve) using larger targets to consider the effect of target frequenc y and size. Two patients were followed longitudinally and tested after reso lution of the maculopathy. We compared our patients with an age-matched con trol group of 11 people. Results: Temporal modulation perimetry detected larger and more localized d efects in all cases of active CSC compared with static perimetery. There ap peared to be size and frequency tuning to the deficit, with greatest loss b eing found at 16 Hz with small (0.5 degrees) targets. The losses resolved i n one case where the retina recovered in 4 weeks, but remained to a lesser degree in another case who suffered a 2 year long fluctuating course before the CSC subsided. Conclusions: Temporal modulation perimetry detects a loss of flicker sensit ivity in patients with CSC. Deeper and more clearly defined scotomata are f ound with a flickering stimulus compared with a steady state one. The great est losses of flicker sensitivity are found with 16 Hz modulation and with small targets located directly over the lesion. The duration of the disease may be important for recovery of flicker sensitivity. Temporal modulation perimetry appears to be a valuable tool for the confirmation of functional loss due to CSC.