Venous occlusive disease is a leading cause of irreversible vision loss, yet trends and risk factors for the condition are largely understudied. New research suggests that the onset of vein occlusion could differ based on age, gender and laterality. The study investigated possible associations by observing all cases diagnosed as RVO in the Academy of Ophthalmology’s IRIS Registry between 2013 and 2017, which included over 1.2 million events. The subtypes were categorized as either retinal artery occlusion (RAO) or retinal vein occlusion (RVO).

Age is a well-known risk factor for retinal vascular occlusion, so it’s no surprise that the incidence of the disease was found to increase with age regardless of the subtype for RAO and RVO. However, the study may have identified some potential subtype-specific disease onset differences associated with laterality and gender.

The study observations indicated a left-eye preference in most subtypes of RVO, except branch retinal vein occlusion (BRVO). A right-eye preference was observed for arterial occlusions. Though most people are right-eye dominant, this can’t be the only explanation for this laterality preference, since venous occlusion was not apparent with the same right-eye preference in observed patients. The researchers noted another possible explanation: “There is a pathophysiologic reason to expect that arterial occlusions would present more commonly in the right eye, as the emboli from the heart would be more likely to block the right central retinal artery,” they wrote in their paper.  Laterality preferences do exist, depending on subtype; now, it’s just a matter of conducting further studies to pin down the unique reasons why.

All retinal vascular occlusion subtypes, with the exception of venous engorgement, were found to have a significantly higher unilateral than bilateral onset rate. If a patient does present with bilateral retinal vascular occlusion, it is likely that one eye may have already had impending or partial occlusion of retinal veins that was asymptomatic and latent, which is why both eyes may end up being diagnosed at once.

Gender may also be linked to differences in RVO onset. Men made up a slightly lower percentage of cases compared to women (48.2% and 51.8%, respectively). Though this statistic in itself is not significant, there were several notable gender differences among the subtypes of the disease. Partial retinal artery occlusion, branch retinal artery occlusion, central retinal artery occlusion and central retinal vein occlusion were more prevalent in men. For women, transient retinal artery occlusion, venous engorgement and BRVO were more common.

Subtype-specific differences related to gender and ocular laterality can be observed in patients with vein occlusion, but further research is needed to determine exactly how these factors affect disease onset. Paying attention to the trends of a patient’s subtype could help to explain the risk factors that led to their diagnosis and provide more individualized treatment. Warning patients who may be at a higher risk of developing occlusive events helps to educate and inform them about how crucial it is to be proactive with proper eye care and regular office visits to help preserve eye health.