The vitreous gel occupies the largest space in the eye, extending from the back surface of the lens, to the retinal surface. It is an embryonic remnant and undergoes ageing like every other organ in the body. At birth it is solid and completely transparent, but as one ages it starts to develop small liquid-filled lakes. These become larger and the edges can be seen as floaters. In general this type of floater is not dangerous- it occurs gradually and in small numbers. As the fluid composition of the gel increases, it begins to exert tension on its insertion on the retina, eventually pulling loose. At this stage , one may be aware of ‘flashes and floaters’- tiny flashes of lightning-like light, with a sudden change in the floaters. Examination at this stage will confirm the presence of a vitreous detachment, and it is important to exclude a retinal tear. From the preceeding symptoms one cannot distinguish whether a retinal tear is present or not. Should the vitreous separation cause a tear in the retina, fluid can leak through the break and cause the retina to lift off the wall of the eye. When this happens , the detached retina doesn’t see and one will be aware of a visual field defect in the area where the retina is detached. This defect will progress towards the centre of fixation- it is important to treat a retinal detachment prior to this as macular detachment means variable degrees of permanent loss of vision. Retinal detachment is one of the few true eye emergencies and one should not hesitate to seek help if the symptoms above occur. Retinal detachment surgery is in-hospital and usually overnight, depending on travel circumstances and home-support. During the surgery, the vitreous gel is removed , all the holes identified and marked, and the retina reattached by pumping air into the eye whilst removing fluid in the eye. Once the retina is reattached, laser to the tears is performed, and a tamponade is used; gas or oil. The function of the tamponade is to allow for the retinal laser to form a scar and stick the retina down where it is torn, whilst excluding any liquid from the tears. It is important that the gas is in apposition to the hole, and to that end, you will be advised on how to posture for the first 5 days post-operatively. Posturing is all day and night, only getting up to go to the toilet or eat and drink. Definitely the most ‘un-fun’ part of retinal surgery. Vision in the eye will also be very poor, as gas causes light to defocus severely. Whilst there is gas present in the eye it is CRITICAL to not travel to altitude more than 300m above sea level, or to fly in an aeroplane. Your eye could be blinded if you do. If silicone oil is used, further surgery is required to remove it.
