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Few and contrasting data are available on the presence of a thrombophilic state in patients with retinal vein occlusion (RVO), and we have previously demonstrated a role of elevated PAI-1 activity as a risk factor for this condition. The present study was undertaken to investigate whether PAI 4G/5G and ACE I/D polymorphisms are independent risk factors for RVO and whether they account for elevated PAI-1 activity levels. We studied 112 RVO patients (52 males and 60 females; range 18-83 years; median age 60 years) and 112 healthy subjects (52 males and 60 females; range 20-84 years; median age 57 years). PAI-1 activity was determined by a chromogenic assay and ACE I/D and PAI-1 4G/5G polymorphisms by polymerase chain reaction (PCR) and restriction length fragment polymorphism (RLFP) methods. Elevated PAI-1 activity (above 95(th) percentile of the controls) was significantly associated with RVO at multivariate analysis after adjustment for age, sex, traditional cardiovascular risk factors and haemostasis-related risk factors (OR = 4.93, 95% CI 1.70-14.30; p = 0.003). The homozygosity for ACE DD was found to be an independent risk factor for RVO at multivariate analysis (OR = 1.98, 95% CI 1.01-3.83; p = 0.049), whereas no significant association between homozygosity for PAI-1 4G4G and risk of RVO was observed. Subjects carrying both ACE DD genotype and PAI-1 4G4G genotype showed an increased risk for RVO at multivariate analysis (OR = 4.82, 95% CI 1.89-12.29; p = 0.001). In 45/112 patients without the established risk factors for RVO (hyper-tension, hypercholesterolemia and diabetes) or characteristics known to be associated to increased PAI-1 activity (overweight, hypertriglyceridemia, and smoking habit) the contemporary presence of ACE DD and PAI-1 4G4G genotype was significantly associated with a risk for RVO (OR = 8.26, 95% CI 1.18-57.92; p = 0.034). In conclusion, in our study: 1-indicates that ACE DD genotype is a risk factor for RVO in the whole group of patients, and in the subgroup of patients without the established risk factors for RVO or characteristics influencing the PAI-1 activity, when associated to PAI-1 4G4G genotype, and 2-confirms the role of hypofibrinolysis, documented by high levels of PAI-1 activity, in the occurrence of patients with RVO.

The authors evaluated, by means of color Doppler imaging, the blood flow of the ophthalmic artery, ciliary arteries and central retinal artery in normal and glaucomatous subjects. In normals they found that flow velocities of all considered vessels progressively decline while resistivity indices increase with advancing age. In glaucomatous subjects there was a statistically significant reduction of the mean systolic peak flow velocity of the ophthalmic artery in comparison with normals. Glaucomatous eyes with uncontrolled IOP and with visual-field worsening showed a statistically significant decrease in the end-diastolic flow velocities and an increase in the resistivity index values in ciliary arteries.

Ocular thermography paves the way to become an effective tool for differentiating between the two different etiologies of dry eye syndrome.