Aqueous flare intensity in relation to different stages of diabetic retinopathy

To compare laser flare intensity in patients with diabetes mellitus (DM) type I and type II to different stages of diabetic retinopathy (DR) and controls.

This study comprised 88 consecutive patients with DM type I and 40 controls in the same age range, divided into two age groups: 20-34 years and 35-50 years; 108 consecutive patients with DM type II and 32 controls were also divided into two age groups: 45-59 years and 60-75 years. Patients with glaucoma, exfoliation syndrome, media opacities, uveitis, within 96 hours after laser photocoagulation, treatment with topical and systemic drugs which can affect aqueous protein concentration, were excluded. One eye was randomly selected from each diabetic patient and control. Flare intensity was measured with a laser flare meter without mydriatic drops, and was then correlated with the stages of DR within each age group.

Eyes with advanced DR, such as moderate-severe, severe non-proliferative DR and proliferative DR (PDR), had significantly higher flare intensity than controls and eyes without retinopathy in all age groups (p<0.05). Flare intensity values were similar for controls and eyes with mild-moderate DR in all age groups except the older patients with DM type II, particularly those with clinically significant macular edema (CSME) (p<0.05). Eyes with regressed proliferative DR and no indication for laser photocoagulation had significantly lower flare values than eyes with an indication for therapy (p<0.05). Eyes with iris rubeosis (IR) had significantly higher flare than those without IR (p<0.05). Flare values were significantly correlated with the duration of diabetes in DM types I and II (p<0.05).

Flare intensity was increased in eyes with mild-moderate DR with CSME, and in eyes with advanced and severe stages of DR. Aqueous flare was related to the duration of diabetes.