Diurnal variation of macular oedema in CRVO: prospective study

Abstract

Patients with CRVO demonstrate increase in CMO in morning compared with late morning and afternoon. Possible causes are diurnal variation in blood pressure, retinal metabolism and erect posture. Interventions designed to influence these factors could be used to try to reduce CMO severity.

Diurnal Variation of Retinal Thickness in Healthy Subjects

“…It has been suggested that the change in body position from recumbent at night to upright at daytime is the most important factor leading to thinner measurements in the evening than in the early morning. 3,17 Polito et al 24 evaluated the effect of posture on diurnal variation in patients with diabetic macular edema. The average relative decrease in foveal thickening between 9 AM and 6 PM was 20.6% in the group forced to maintain upright position during the day compared with 6.2% in patients who were strictly confined to bed (supine position).…”

“…All significant changes in RNFL thickness or macular thickness/volume measurements were toward smaller values in the evening, comparable to changes reported in patients with macular edema. 3,16,17 Several mechanisms have been postulated to explain diurnal variations of retinal thickness in patients with macular edema. It has been suggested that the change in body position from recumbent at night to upright at daytime is the most important factor leading to thinner measurements in the evening than in the early morning.…”

Central Retinal Vein Occlusion

“…This circadian change may In such a situation, nocturnal arterial hypotension during the acute phase can also result in the same. There are several reports of development of CRVO and central retinal artery occlusion, which is a variant of the above, as discussed elsewhere [ 248 ].…”

Influence of Orthostasis and Daytime on Retinal Thickness in Uveitis-Associated Cystoid Macular Edema

“…Nevertheless, each study reported some kind of diurnal central thickness decrease. 6,9,[13][14][15][16] Only a few studies evaluated parafoveal diurnal thickness changes beside CRT, 10,13,15,16 and only Polito et al evaluated diurnal changes in ETDRS subfields in CME. 5 Thus, Polito et al's results seem most comparable to our findings.…”

“…5,6 The present study was the first to analyze retinal fluid mobility during the daytime and the influence of rapid orthostatic changes on fluid distribution and retinal thickness in uveitis patients, using a new high definition SD-OCT.…”