Silicone oil concentrates fibrogenic growth factors in the retro-oil fluid

AIM

To determine whether silicone oil concentrates protein and growth factors in the retro-oil fluid.

METHODS

A laboratory analysis of intraocular fluid and vitreous specimens obtained from patients undergoing removal of silicone oil, revision vitrectomy, or primary vitrectomy for macular hole, proliferative vitreoretinopathy (PVR), or retinal detachment. Patients were prospectively recruited from routine vitreoretinal operating lists. Vitreous cavity fluid and vitreous samples were analysed for the presence of transforming growth factor beta (TGF-beta2), basic fibroblast growth factor (bFGF), interleukin 6 (IL-6), and total protein using either commercially available enzyme linked immunosorbent assays (ELISA) or protein assay kits.

RESULTS

The median levels of bFGF, IL-6, and protein in the retro-oil fluid were raised (p<0.05) compared to all the other vitreous and vitreous cavity fluid samples. bFGF, IL-6, and protein levels were raised in PVR vitreous compared to non-PVR vitreous. TGF-beta2 levels were not significantly raised in retro-oil fluid or in PVR vitreous.

CONCLUSIONS

The concentration of fibrogenic (bFGF) and inflammatory (IL-6) growth factors and protein is raised in retro-silicone oil fluid. This may contribute to the process of retro-oil perisilicone proliferation and subsequent fibrocellular membrane formation.

Simple retinal detachments: identifying the at-risk case

The success rate of retinal reattachment surgery has now reached over 90%. The major cause of failure is attributable to the development of proliferative vitreoretinopathy (PVR). It is a complex process comprised of events that are similar to those of the wound healing response with inflammation, migration and proliferation of a variety of cells. These membranes can exert traction and reopen previously closed retinal breaks, create new breaks, and distort or obscure the macula. In the early part of this century the success rate of retinal reattachment surgery was virtually nil and it was not until a better understanding of the pathophysiology of retinal detachment was gained that the success rate improved. It was Gonin who emphasised the relationship between vitreous detachment and traction resulting in retinal tears that led to treatment aimed at closing retinal breaks. To increase even further the final success rate in the treatment of 'simple retinal detachments' a better understanding of the risk factors for PVR is needed in patients presenting with acute retinal detachments. Such risk factors can be broadly divided under the headings of preoperative risk factors, best surgical management and possibly adjuvant therapy.