What is the retina?
The retina is a thin neurosensory tissue that lines the inside rear wall of the eye. It captures light focused from the front of the eye and processes it into signals sent through the optic nerve which connects to the visual processing sites of the brain. In other words, the retina is the first nerve tissue to act as a light sensor in the cascade of receiving and processing images and objects from the visual world.
What is the normal retinal position?
In its normal state, the retina is attached to the back wall of the eye, resting up against the retinal pigment epithelium (RPE) and the orange choroid layers immediately behind it (top photo). The immediate proximity of these layers is crucial for normal retinal function, because the RPE carries out important nutritional and functional processes, and the choroid supplies two thirds of the retina's blood and oxygen supply. Any separation of the retina from these two layers behind it (lower photo), and the retina will lose its normal function.
What causes a retinal detachment?
The vast majority of retinal detachments occur spontaneously without any injury to the eye or other cause. But having suffered prior eye trauma significantly increases the likelihood of retinal detachment. Prior eye surgery increases the risk by a smaller degree. Very near-sighted eyes with a strong minus prescription (e.g. -8.00 or greater) are also at risk for retinal detachment.
What are the symptoms?
The process most often begins with a *vitreous* detachment, with the vitreous being the clear gelatinous material that fills the largest cavity of the eye and rests in front of the retina. The vitreous is attached to the retina when we are young, and as we age into the 5th and 6th decades of life, the vitreous separates. This *vitreous* detachment results in new floaters visible from the eye, and a bit of vitreous tugging on the retina can stimulate nerve signals that appear as flashing lights, often described as lightning bolts seen from the outside corner. At this stage, 10-15% of patients with a *vitreous* detachment may have a hole or tear in the retina. If the torn retina progresses to a *retinal* detachment, a blind spot may first be noticed in the peripheral vision, and the blind spot eventually enlarges to involve the central vision and the entire visual field.
How are torn and detached retinas treated?
If the 10-15% of patients with a *vitreous* detachment who have a hole or tear in the retina make it into the clinic with sufficient urgency, the hole can be treated with an in-office laser that seals the edges and prevents it from evolving into a detached retina.
Once the retina detaches, it must be treated with outpatient day surgery in the operating room. Patients go home the same day but require a driver. The vast majority of patients with retinal detachment are in their 5th or 6th decade of life or older, and for these patients Dr. Kavoussi will most likely recommend a vitrectomy surgery. Much less commonly, young patients in their 20s or 30s present with retinal detachment, often due to severe near-sightedness or prior injury. For these patients, Dr. Kavoussi may recommend a scleral buckle procedure. Both vitrectomy and scleral buckle have a single surgery success rate between 80 and 90%.
Certain cases are amenable to a staged office procedure called pneumatic retinopexy, whereby gas injection is performed in the clinic, followed by office laser 2-3 days later. The success rate of this procedure is lower than vitrectomy and Dr. Kavoussi may recommend it only if the location characteristics of the retinal detachment make the patient an ideal candidate, or if medical co-morbidities like heart disease cause difficulty for the patient to be deemed healthy enough to have day surgery.