Fibrovascular ingrowth and recurrent haemorrhage following diabetic vitrectomy.

Aim: To investigate the prevalence and the outcome of management of fibrovascular ingrowth (FVI) in eyes undergoing vitreous cavity washout (VCWO) following vitrectomy for diabetic retinopathy.
Method: FVI was searched for at VCWO for in 19 consecutive eyes with proliferative diabetic retinopathy undergoing vitreous surgery for recurrent vitreous cavity haemorrhage over an 18 month period; the findings were correlated with the presence or absence of associated sclerotomy vessels externally. Eyes with richly vascularised ingrowths from the pars plana entry sites, as well as eyes with less extensive ingrowths but extensive retinal ablation applied at previous surgery for recurrent haemorrhage, underwent lensectomy and ciliary membrane dissection in addition to extensive retinopexy (n=6). Less severe cases received peripheral laser and cryotherapy only. The outcome of repeat surgery was studied prospectively in the 11 eyes with FVI.
Results: 11 of the 19 eyes had a definite FVI from one or more of the original pars plana sclerotomies. In six of 11 eyes with FVI a large external episcleral vessel was present entering the original sclerotomy sites at which ingrowth was found peroperatively, but such sclerotomy vessels were also present in three of eight eyes with no FVI detected on the internal aspect of the sclerotomy. Two patients were lost to follow up and the remaining nine patients with FVI had no further vitreous cavity haemorrhage during initial follow up of 2-5 months.
Conclusions: FVI has until now been considered an infrequent occurrence following vitrectomy for diabetic retinopathy. These findings would suggest that it is not uncommon and careful examination of the sclerotomy sites should be undertaken in all cases with recurrent haemorrhage and if FVI is found this should be treated appropriately.