Session Title: Vitreoretinal Surgery II
Session Date/Time: Thursday 26/09/2013 | 14:30-16:00
Paper Time: 15:34
Venue: Hall 3 (Level 0)
First Author: Z.Shalchi UK
Co Author(s): O. Mahroo M. Shunmugam M. Mohamed T. Williamson
Silicone-oil related visual loss occurs in up to 10% of oil filled eyes which experience acute loss of central vision at the time of removal of silicone oil (ROSO) or whilst it is in situ. To date, no anatomical changes have been documented in either the retina or optic nerve. We wanted to investigate affected eyes using spectral domain optical coherence tomography (OCT).
St Thomas' Hospital, London
We identified 4 patients with silicone oil-related visual loss. All had vitrectomy with silicone oil tamponade for macula-on retinal detachment, and were reviewed 4-9 years thereafter. Three lost vision with oil in situ, with one at the time of removal. Patients attended for assessment of best-corrected visual acuity (BCVA), contrast sensitivity, Farnsworth Munsell (FM) 100 Hue testing, static perimetry, scanning laser ophthalmoscope (SLO) and autofluorescence imaging as well as spectral domain OCT imaging of the macula and optic disc. Patients also underwent full-field electroretinography.
Long-term logMAR BCVA was significantly reduced in affected eyes (range, 0.44 – 1.00), as was contrast sensitivity (0.75 – 1.35) and colour discrimination (FM-100 Hue scores 151 – 390). Static perimetry showed a central scotoma in all affected eyes. SLO and autofluorescence imaging revealed non-specific findings. Macular OCT revealed microcystic macular changes in the inner nuclear layer of all affected eyes associated with a severe loss of the papillofoveal retinal nerve fibre layer (RNFL). In one patient, serial OCT images showed the development of microcystic macular changes 18 months after ROSO.
To our knowledge, this is the first study looking at long-term follow up in patients with silicone oil-related visual loss, and the first to use spectral domain OCT to examine macular morphology in this group. We have demonstrated microcystic macular changes in the inner nuclear layer of affected eyes, as well a focal and severe RNFL loss of the papillofoveal projection. These changes share significant similarities with morphological features reported in multiple sclerosis-associated optic neuritis, Leber hereditary optic neuropathy, and Tanzanian endemic optic neuropathy.