Complaints such as suddenly seeing flashes of light or floaters in the eye may be a sign of posterior vitreous detachment, i.e. detachment of the eye’s gel-like fluid that fills the inside of the eyeball from the retina, or retinal tear. In posterior vitreous detachment, age-related changes in the vitreous gel weaken the bonds between the retina and vitreous gel, causing the vitreous gel to detach from the retina spontaneously or sometimes due to trauma. It is more common in myopes. Cataract surgery and traumas may facilitate detachment.

Opacities in the vitreous gel, cells shedding into the vitreous gel during division and small hemorrhages get displaced by eye movements and as they enter the optical axis, they create the impression of “flying flies”. When the vitreous gel pulls on the retina, it causes “flashes of light”.

Sudden vitreous detachment may cause retinal tear in 10-15% of cases. Retinal tears must be treated immediately as the ocular fluid may pass behind the retina through the tear, causing the retina to separate and detach from the back of the eye. Retinal tears can also occur without posterior vitreous detachment for various reasons, notably trauma.

To treat retinal tears, the pupil is dilated with drops, the location of the tear is determined with the help of lenses, and a laser beam is directed into the eye through the pupil to make small burns around the tear in the retina. The burns create small scars that help hold the retina in place and attach it to the eye ball so that passage of fluid under the retina and thus retinal detachment is prevented. 

When retinal detachment happens, a dark shadow or “curtain” occurs on the sides or in the middle of your field of vision and there may be partial or complete loss of vision. Retinal detachment requires immediate surgical treatment. Delaying surgery reduces the chance of success. If left untreated, blindness is inevitable. During the surgery, pressure is applied to the outer wall of the eye by placing silicone bands under the conjunctiva, the membrane layer. After removing any fluid buildup between the retinal layers, argon laser or cryotherapy is used to close the area around the tear and gas is injected into the eye (pneumatic retinopexy) to soothe the retina.