Vitrectomy (twice, to insert silicone oil and to remove it)
Is a permanently dilated and fixed pupil a normal side effect of vitrectomy surgery that includes laser treatment, or is it caused by surgical error that damages the nerves controlling the pupil?
Thanks for your Question
Tonic pupil or Fixed Dilated Pupil after vitrectomy surgery can be caused by thermal damage to short ciliary nerves by endolaser photocoagulation. Endolaser is very important during vitrectomy surgeries and one of its common but undesirable complications is tonic pupil.
Short ciliary nerves pass through suprachoroidal space to supply iris muscles and damage to these nerves will affect pupil dilation. It can be a transient effect with gradual return to normal or near normal within months due to re-innervation or sometimes it is a permanent damage,