Abstract
Purpose: :
To explore the causes of vision fluctuations in patients with chronic macular edema.
Methods: :
Fifteen patients (16 eyes) with vision blurring at awakening due to post– central retinal vein occlusion macular edema underwent three examination sessions over 24 hours (at 7 PM, immediately after awakening at 7 AM, and at 7 PM), which comprised measurement of Early Treatment Diabetic Retinopathy Study (ETDRS) score, and of macular thickness (MT) by optical coherence tomography. Ocular perfusion pressure (OPP) was calculated from ambulatory arterial pressure measurement. Additionally, after the 7AM measurements, the patients were randomized for monocular light deprivation during the day in order to evaluate the role of retinal illumination in these fluctuations.
Results: :
Circadian fluctuation of MT was documented in all patients. At 7AM, mean VA was worse (mean ± SD of the difference: 6.5 points ± 7.2 ; p< 0.002) and mean MT was higher (57.4 microns ± 34; p< 0.001) than at 7 PM. Fluctuations of MT were correlated to fluctuation of arterial pressure (p=0.05), but were not influenced by monocular light deprivation.
Conclusions: :
In most patients complaining of visual fluctuations due to macular edema secondary to central retinal vein occlusion, MT and VA was found to undergo a circadian cycle. These short–term anatomical and functional variations were associated with arterial pressure variations, that is, macular thickening was inversely correlated to the arterial pressure drop during the night, but were not due to light deprivation.
Keywords: clinical (human) or epidemiologic studies: natural history • vascular occlusion/vascular occlusive disease • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)