Platelet indices in retinal vein occlusion in hypertensive patients.

Sir,

We read the article by Onder et al. with great interest.[1] The authors measured the mean platelet volume (MPV) in hypertensive patients with branch retinal vein occlusions (BRVO). They found that hypertensive patients with BRVO have significantly higher MPV than controls, suggesting higher platelet activity. This is an interesting study. However, we want to make some minor criticisms about this study.

In generally method of MPV assessing is correct. They studied the blood samples within 2 h to prevent ethylenediaminetetraacetic acid induced swelling. On the other hand, there are significant associations of MPV with diabetes mellitus, pre-diabetes, hypertension, hypercholesterolemia, obesity, metabolic syndrome, smoking, statin and some antihypertensive drug use and atrial fibrillation.[23] These factors can influence the MPV values. Although the authors excluded some chronic diseases, data of cardiovascular diseases including coronary artery disease, body mass index, antihypertensive drugs and statin use is lacking. The mean age of the patients is 62-year-old and some of them may have cardiovascular disease at this age. It has also been shown that some antihypertensive drug and statin use can affect MPV values.[456] When we look at, nearly all patients and controls are hypertensive. However, there is no data about drugs used in these patients and controls. We believe that, it would be useful, if the authors provided data about these risk factors and their possible relationship with MPV and hypercholesterolemia.

In our previous study, we found that MPV was significantly elevated in patients with deep vein thrombosis compared with controls.[7] Platelet activation might occur with a similar mechanism in patients with BRVO and deep vein thrombosis. We think that patients with BRVO are under risk of other cardiovascular disorders and must be investigated from this aspect.