Retina Detachments by: Adam AufderHeide, MD, PhD

A retinal detachment (RD) is a sight threatening emergency. It occurs when the thin layer of tissue in the back of the eye that is sensitive to light pulls away from the layer of the eye with blood vessels that supply its nutrients. The classic symptoms of a retinal detachment are flashes of light, floaters, and the visual sensation of a curtain coming over the vision in that eye. The incidence of RD varies between 6-18 per 100,000 per year depending on the study and population.

There are several risk factors for having an RD including being near sighted, a history of eye trauma or previous eye surgery. Having cataract surgery is a risk factor for RDs, but that shouldn’t prevent a patient from having cataract surgery. It’s something they should be made aware of so if they have any of the symptoms of an RD, they should get to their eye doctor right away and not ignore it. Other, less common, risk factors are certain syndromes such as Marfan and Stickler syndromes.

The best advice for people who are having symptoms of a RD is to seek the aid of an eye doctor who can dilate their eyes for evaluation. Emergency rooms are generally not the fastest way to get evaluated for an RD because they don’t generally have the equipment to do dilated eye exams there. Once an RD has been established, the treatment needs to be tailored to the individual patient. We categorize retinal detachments by whether the portion of the retina that contains the central vision is still attached. These are called macula-on or macula-off retinal detachments. This classification will determine how urgent surgical repair is. Which type of surgery also depends on the extent of retina detached and the location of the breaks.

The most common mechanism of what causes an RD is associated with a posterior vitreous detachment (PVD). The vitreous is the gel that fills the vitreous cavity (from the back of the lens to the retinal surface). This gel is mostly water but also contains collagen. This gel shrinks over time. It’s firmly attached at the front of the eye, just behind the lens, and not so firmly attached at the back of the eye. Thus, when it shrinks, it pulls on the retina and the vitreous detaches from the back of the eye while staying attached to the vitreous base. This pulling on the retina causes the “flashes” that people notice during either a PVD or an RD. As the gel shrinks, it condenses causing floaters. Sometimes traction on a small blood vessel in the retina can cause bleeding into the vitreous which will also cause floaters. In most people, a PVD doesn’t cause any problems, but the risk is that when the vitreous is detaching from the retina, it causes a break or tear in the retina. This tear allows liquid vitreous to get behind the retina and cause a retinal detachment. As an RD progresses, it gives the sensation of a curtain coming down over the vision. Where the retina is attached, vision is essentially normal. Where it’s detached, vision is greatly diminished. If a patient has any of these symptoms, they should be evaluated as soon as possible because time is vision while the macula is attached.

By Adam C. AufderHeide, MD, PhD