5.2.2 Subretinal Perfluoro-n-Octane PFO Removal and Displacement
Subretinal perfluorocarbon liquid (PFCL) occurs in up to 11% of surgeries that utilise it. Subfoveal and sub-papillomacular bundle PFCL have the most significant visual implications. Visual loss may be due to mechanical alterations or a direct cytotoxic effect. It is accompanied by retinal thinning on optical coherence tomography (OCT) and a scotoma on microperimetry. Factors that increase the risk of subretinal PFCL include large retinal breaks, 360° retinectomy, residual traction around retinal breaks, and the use of small gauge instrumentation.
Not all subretinal PFCL requires removal. Despite subfoveal location, Nowilaty et al.[1] reported stable visual acuity of 20/40 over 10 years of observation. Extrafoveal PFCL is usually well tolerated with minimal impact on vision.[2,3] Observation is often the preferred approach in these cases. Subretinal PFCL may rarely migrate towards or away from the fovea, with one report describing spontaneous extrusion through a macular hole which subsequently closed without intervention.[4] In cases where subfoveal PFCL causes poor visual acuity, early surgical removal should be considered.
There are three surgical approaches for subfoveal PFCL removal:
- direct transretinal aspiration,
- displacement to an extramacular region by inducing a macular detachment and utilising post-operative posturing
- displacement and subsequent PFCL removal through an extrafoveal retinotomy.
Nowilaty SR. Ten-year follow-up of retained subfoveal perfluoro-N-octane liquid. Retin Cases Brief Rep 2007; 1: 41–43.
Garcia-Valenzuela E, Ito Y, Abrams GW. Risk factors for retention of subretinal perfluorocarbon liquid in vitreoretinal surgery. Retina 2004; 24: 746–752.
Suk KK, Flynn HW Jr. Management options for submacular perfluorocarbon liquid. Ophthalmic Surg Lasers Imaging 2011; 42: 284–291.
Oellers P, Charkoudian LD, Hahn P. Spontaneous resolution of subfoveal perfluorocarbon. Clin Ophthalmol 2015; 9: 517–519.
Direct transretinal aspiration may be preceded by internal limiting membrane (ILM) peeling to minimise the risk of a persistent macular hole.[5] Placing an intravitreal PFCL bubble on the macula before subfoveal PFCL aspiration may reduce the size of the foveotomy.[6] Gentle aspiration with a small gauge cannula (40-50G) from the edge or on top of the PFCL bubble is performed to prevent a submacular haemorrhage and subsequent fibrosis.
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Westmead Eye Manual
This invaluable open-source textbook for eye care professionals summarises the steps ophthalmologists need to perform when examining a patient.
