Taken into consideration that the main systemic comorbidity in retinal vein occlusion is a systemic hypertension hopefully this paper shed a light on your question.

Seasonality and incidence of central retinal vein occlusion in sweden: a 6-year study.

David Epstein, Anders Kvanta, and Pelle G Lindqvist

Ophthalmic Epidemiology 22(2):94 (2015) PMID 25777308

To investigate seasonality in onset and incidence of central retinal vein occlusion (CRVO) in Stockholm, Sweden. A retrospective consecutive population-based case series of patients presenting to the emergency department with CRVO from January 2008 through December 2013 at the St Erik Eye Hospital. Date, age at occurrence and sex were recorded in the study cohort. A total of 854 patients presented with CRVO during the study period. Peak CRVO onset occurred during the winter/spring period and was significantly higher than during the summer/autumn period. The number of patients presenting by season were: 166 (28.8%, 95% confidence interval, CI, 25.3-32.6%) in winter, 172 (29.9%, 95% CI 26.3-33.7%) in spring, 131 (22.7%, 95% CI 19.5-26.3%) in summer, and 107 (18.9%, 95% CI 15.6-22.0%) in autumn (p 

I have observed seasonal changes in the production of reaction oxygen species. I explored the idea and that's what I have found  - read my recent paper. http://www.ncbi.nlm.nih.gov/pubmed/21112335

Interesting paper Emilia

Some data showed that temerature and ratio of day/night period might influence BP. Higher temperature: vessel dilatation and sweating.

Any data on prognostic value of this phenomenon exist.

Also, check this out

http://www.ncbi.nlm.nih.gov/pubmed/?term=kutyifa+v+circadian