The effect of intraocular silicone oil on anterior chamber oxygen pressure in cats
E. de Juan Jr, M. Hardy, D. L. Hatchell and M. C. Hatchell
Intraocular silicone oil has been observed to lessen the incidence of
neovascular glaucoma in patients with a high risk of anterior segment
neovascularization. In order to test the hypothesis that the presence of
silicone oil in the vitreous cavity acts as a diffusion/convection barrier
to oxygen and prevents the decrease in anterior chamber oxygen tension that
occurs after lensectomy and vitrectomy, we measured anterior chamber oxygen
pressure in six cats that had undergone lensectomy-vitrectomy in one eye
and lensectomy-vitrectomy with silicone oil placement in the other eye ten
to 21 days previously. The anterior chamber oxygen tension was 17.8 +/- 6.9
mm Hg (mean +/- SD) in the eyes that had undergone lensectomy-vitrectomy
and 34.8 +/- 3.5 mm Hg in the silicone oil-treated eyes (P less than .001).
Silicone oil does appear to act as a diffusion/convection barrier to oxygen
and may alter the stimulus for anterior segment neovascularization.
