Solitary silent venous papillary loops and ocular hypertension.

Abstract

A series of 24 eyes in 23 patients is described showing solitary silent venous papillary loops. These loops are usually associated with a considerable degree of ocular hypertension, presenting when this hypertension is being investigated. They are silent, usually with no previous ocular history, single with a large diameter, affecting veins at the optic disc and not extending into the vitreous. The optic disc is cupped, but usually not more than 0.6 disc diameter, there is good central vision and either a full visual field or only early field loss. Fluorescein angiography shows the loops to be competent with no evidence of any other retinal vascular abnormality. Rarely loss of central vision may occur due to progression to advanced glaucoma. The condition is distinct from prepapillary vascular arterial papillary loops, neovascularization at the optic disc and optociliary shunt vessels. It is also distinct from the venous collateral vessels which develop at the optic disc after acute central or branch retinal vein occlusion. These collaterals are usually multiple, the accompanying ocular hypertension is of lesser degree, cupping of the disc and field loss are usually much more advanced and, while visual acuity may be normal, it is often grossly reduced. On fluorescein angiography all these cases of venous collaterals after retinal vein occlusion showed evidence of other retinal vascular dysfunction. Solitary silent venous papillary loops appear to develop from venules on the optic disc as a bypass to a low grade venous occlusion which is seldom clinically manifest. They form a distinct entity with a good prognosis if the accompanying ocular hypertension is carefully controlled.