Preretinal and vitreous haemorrhages are commonly seen in proliferative diabetic retinopathy. They occur particularly at the stage of active growth of the new vessels (Stage II: Dobree, I 964), and are less frequently seen when connective tissue is being laid down in and around groups of new vessels.There is no doubt that repeated vitreous haemorrhages give rise to various forms of fibroplasia, which reduce the clarity of the media and in some cases lead to traction retinal detachment (Winter, I967). Although there is general agreement about the occurrence of preretinal haemorrhages, there is no such agreement about the sequelae. Duke-Elder (I967) stated that small preretinal haemorrhages were rapidly absorbed with full restoration of vision, and that larger preretinal haemorrhages, which were absorbed more slowly, might damage the nerve-fibre layer with subsequent atrophy. Tolentino, Lee, and Schepens (i966), who studied haemorrhage and retinal detachment in I6I eyes, found that preretinal haemorrhages were either absorbed completely, leaving only a few white deposits of fibrin on the posterior detached vitreous face, or if very large, remained unabsorbed for months. Larsen (i 960) described greyish silk-like veils lying in front of preretinal haemorrhages and found that they preceded detachment ofthe posterior vitreous face. He thought that they indicated degenerative changes in the hyaloid face. Wetzig and Jepson (I966) also mentioned a permanent reduction in vision after preretinal haemorrhage in one case, but did not discuss this further.It is the purpose of the present paper to focus attention on the observed permanent sequelae to preretinal haemorrhage in a series of patients with proliferative diabetic retinopathy who have been reviewed regularly by serial fundus photography.
Clinical materialA series of 1 14 eyes from 59 patients have been studied over a period of 4 years, during which 44 preretinal haemorrhages were seen and photographed in 38 eyes. It is not suggested that this was the total number of such haemorrhages in these patients; as they are so localized, it is possible that some may have been unnoticed by the patient in the 3 to 4-monthly intervals between out-patient attendances. The 44 preretinal haemorrhages were seen in all four quadrants of the fundus, often remote from the vessels which bled. The site of origin is often clearly indicated by a fine trail of clot.
ObservationsOn ophthalmoscopic examination at subsequent visits, no trace of these haemorrhages was seen in 37 cases, and no sequelae were seen in the serial fundus photographs.Seven preretinal haemorrhages, however, gave rise to permanent sequelae. Three of these lay below the optic disc, two nasal to the optic disc, one in the lower temporal quadrant, and one at the posterior pole.