The Half-Filled or the Half-Empty!

A 34-year-old lady presented with blurring of vision in her right eye since a few months with the best corrected visual acuity being 6/18. The anterior segment was normal, while the fundus examination revealed a full-thickness macular hole with complete posterior vitreous detachment Figure 1b. She was planned for pars plana vitrectomy with internal limiting membrane peeling with sulphur hexafluoride gas (SF6) as tamponade. On the second-week follow-up, the patient presented with closure of the macula Figure 1c with half-filled SF6 gas and showed reflex of the other half retina Figure 1a. Two theories explain the mechanism by which gas tamponade facilitates macular hole closure. The 'waterproofing' theory advocates that the gas bubble helps in hole closure by keeping the macula dry.1 The hole is isolated from the vitreous fluid due to the vitreous humour's high surface tension. Alternatively, the 'floatation force' theory suggests that the bubble helps in displacing the SRF away from the macula as it exerts an upward force due to its buoyancy. Conventionally, non-expansile gas is used.2Figure 1: Optical coherence tomography (OCT) revealed a full-thickness macular hole with complete posterior vitreous detachment; (b) On the second-week follow-up, OCT revealed the closure of the macula (c) with half-filled SF6 gas and showing reflex of the other half retina (a)Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.