A 45-year-old woman was referred from the neurosurgery department for sudden bilateral loss of vision after ventriculoperitoneal bypass surgery for a temporal subdural hygroma and cranial occipital abscess. This was the result of a subacute post-surgical complication. A fortnight earlier she had undergone preventive spinal decompression surgery for Arnold-Chiari I malformation.
The patient had a clinical history of 16 years, with mild headaches, unsteadiness, rotatory dizziness, self-limited vomiting of variable duration and mild vertical nystagmus for a year. The latter led to the suspicion and diagnosis of congenital malformation, as the rest of his symptoms were related to the ulcerative colitis he had been suffering from for years.
Visual acuity (VA) at the first examination was hand movement in both eyes. Pupillary reactions were 2+ with no relative afferent pupillary defect. There was a high-frequency, medium-amplitude downward twitching nystagmus. Fundus examination showed bilateral retrohyaloid premacular and vitreous haemorrhage, confirmed by optical coherence tomography (OCT) and ocular ultrasound. All these findings were compatible with TS.

A posterior hyaloidectomy was performed in his right eye (OD) after instillation of anaesthetic eye drops and use of Nd:YAG laser 15 pulses (range 4-7 mJ/pulse) in the most inferior part of the haematoma. The posterior hyaloid ruptured and immediately drained blood into the vitreous cavity. A watchful waiting approach was chosen for his left eye (OI).
The VA at one year, after several revisions with marked improvement, was 0.6 in the OD and 0.1 in the OI. OCT revealed a premacular epiretinal membrane of recent appearance in his OI. The frequency of nystagmus decreased and the amplitude became mild. Bilateral haemovitreal was still slowly and progressively resorbing.
The patient refused any ocular surgery and was satisfied with the visual result achieved.