Vitreous Sampling

Sampling of the vitreous for toxicological and other forensic investigation (3,4) or for microbiologic studies (6) is best performed on an eye that is intact and without known structural intraocular pathology, such as a retinal detachment. A 15-gauge needle is inserted at an oblique angle through the sclera at a point 5 mm lateral to the limbus (corneo-scleral junction) (Fig. 7-1). The needle will traverse the pars plana and enter the vitreous body. Damage to the retinal cells will result in a falsely high potassium value (the correct vitreous potassium concentration can be used for a rough estimation of the postmortem interval) and thus gentle aspiration of 2-3 mL of vitreous is required. The material, which is drawn into a 10 mL sterile syringe may be stored at 4°C for up to 48 h (see also p. 16 and 113).

In suspected child abuse, vitreous should never be aspirated because there is a risk of artifactual damage to the retina. Instead, prior to the removal of the eye (see below), the fundus should be photographed. It is the retina that bears the brunt of the injury in child abuse and the assessment and position of retinal hemorrhages is of prime importance.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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