The retina is the thin layer of tissue that lines the inside of the eye like film in a camera. It contains over a million neurons including specialized vision cells called photoreceptors. A retinal detachment is a separation of the retina from the wall of the eye, which leads to progressive loss of peripheral and, eventually, central vision. Left untreated, total, permanent loss of sight eventually occurs in most cases.
Causes and Associations
There are different kinds of retinal detachments: rhegmatogenous, tractional, and exudative. A rhegmatogenous retinal detachment is the most common type of retinal detachment and is caused by a defect in the retina, allowing fluids from the vitreous cavity of the eye to track under the retina and detach it from the eye wall. Retinal tears and associated detachments of the retina are usually unpredictable, spontaneous events. Associated risk factors include myopia (near-sightedness), posterior vitreous detachment (PVD), thin patches of peripheral retina (lattice degeneration), previous eye surgery, and trauma.
Patients with rhegmatogenous retinal detachments often notice the sudden onset of floaters (black dots or cobwebs in their vision) and/or flashing lights. A dark shadow or curtain progressing from one’s peripheral vision comes next and this corresponds to the retina detaching. The rate of progression of the retinal detachment can vary from days to weeks depending on many factors such as patient age and size and number of retinal tears.
Retinal detachments often cause some degree of permanent visual field or central visual acuity loss, even after successful retinal reattachment. Final visual outcomes are best if the detachment is detected and treated before it involves the center of the retina (macula). Longstanding retinal detachments typically have a poor visual prognosis. A change of glasses after healing from retinal detachment surgery may or may not improve the vision.
Prevention and Treatment
If a retinal break or tear is detected before there is retinal detachment, laser or cryotherapy (freezing) to the retinal tear is often successful in sealing the tear and preventing a retinal detachment. However, once the retinal detachment develops, one or more of the following retinal reattachment procedures is typically necessary:
Pneumatic Retinopexy is an office-based procedure. It involves injecting a temporary gas bubble to flatten (reattach) a retinal tear and surrounding detachment. The gas injection is coupled with either a freezing treatment (cryotherapy) or laser to permanently seal the causative retinal tear. Success relies on patient cooperation to maintain a certain head position for roughly a week.
Scleral Buckle Procedure consists of suturing a soft piece of silicone to the outside wall of the eye in such a way as to indent the eye wall closer to the retinal tear. The tear is then treated with cryotherapy that seals the tear once the fluid under the retina is either actively drained surgically or absorbed by the body passively.
Micro-incisional Vitrectomy involves the surgical removal of the vitreous gel using an operating microscope and tiny instruments; this relieves the traction that produced the retinal tear(s) and detachment. Laser is used to seal the retinal breaks and at the end of the procedure the eye is filled with either gas or silicone oil. Gas is gradually absorbed away, but oil remains until surgically removed at a later time. (Silicone oil is usually reserved for highly complex retinal detachments such as those associated with abnormal scar tissue.)
Your surgeon will review the risks, benefits and alternatives of the treatment options with you in further detail and make tailored recommendations based on the unique findings of your eye.