Background/Aims A subset of patients with X linked retinoschisis (XLRS) have bullous schisis cavities in the peripheral retina. This study describes the characteristics and prognosis of the bullous form of XLRS.

Methods A retrospective case series was performed of nine patients with molecularly proven bullous XLRS seen at a single tertiary centre.

Results All cases of bullous peripheral schisis were bilateral, with one unilateral case at presentation which developed into bilateral bullous schisis over time. The mean age of onset was 1.9 years (range: 1 month–7 years, SD: 2.1 years) and at clinical diagnosis was 5.9 years (range: 1 month–27 years, SD: 9.0 years). Mean follow-up was 11 years (range: 6 months–36 years, SD: 10.8 years). Strabismus was the most common presentation (n=7). Other presenting complaints included decreased vision, floaters and an irregularly shaped pupil. The most frequently associated ocular features were strabismus (100%), vitreous haemorrhage (4/18 eyes, 22%), nystagmus (2/9, 22%) and persistent fetal vasculature (1/18, 6%). Localised tractional detachment was seen in 2/18 (11%) eyes, total detachment that underwent surgical repair in 1/18 (6%) and pigmented demarcation lines in a further 22% of the eyes. There was one eye with exudative retinal detachment.

Conclusion In XLRS, bullous schisis may be congenital or develop soon after birth and most commonly presents with strabismus. Cases may be complicated by some form of retinal detachment, which may be tractional or a Coats-like exudative detachment.