One of the most common remarks that patients with a serious eye condition make to me is, “But doctor, it didn’t hurt, so I didn’t call!” This is can be a blinding error. The retina is the part of the eye that I specialize in and it does not have any pain receptors! The photoreceptors function is to detect light. These receptors cannot feel heat, pain, cold, vibration, just light. That is why when you push on your eyes you notice light sparkles.
This is a difficult concept for patients and their families to accept because the eye is otherwise an extremely sensitive part of the body. The slightest touch, even a hair in the eye can hurt tremendously! Pain receptors are present in the cornea, the front part of the eye. These are present presumably to prevent people from man-handling this fragile organ.
When a patient develops a retinal tear there is a sensation of lightning that nobody else sees. Black spots commonly called floaters are usually also present and represent the blood or pieces of vitreous in front of the retina. In fact, the entire retina can become detached from the back of the eye without one iota of pain.
In my practice, I see many diabetic patients. Swelling of the macula, known as macular edema is common. No pain is involved. Once visual symptoms of distortion and decreased vision have developed, permanent damage has occurred and treatment is aimed at stopping the progression. Recovering lost vision is unlikely. That is why doctors stress at least annual eye follow up for diabetics.
Diabetics can also develop proliferative diabetic retinopathy where blood vessels grow into the center of the eye. These lead to bleeding and scar formation and eventually collapse of the eye. It is hard to imagine that the massive (on an eye scale) damage doesn’t have any symptoms of pain. Prompt laser or other surgical treatment of this form of diabetic retinopathy is usually effective in halting the disease.
Age related macular degeneration is a very common disease in people over 55. There are two stages of the disease. The first stage is the dry type which generally leads to slow and sometimes mild vision loss. No pain is experiences as the retinal cells die off. The only treatment at this time involves taking high doses of particular vitamins. This is helpful but not terribly preventative. The second stage is the wet type. This usually leads to rapid and terrible vision loss as blood vessels grow underneath and into the retina. Large hemorrhages may develop and no pain is involved. Injections of Macugen, Lucentis, laser treatments and surgery are available and effective if the patient is seen within a short time usually a day or two.
These are examples of common painless eye conditions. With all the treatments available for these blinding diseases, please don’t ignore eye symptoms because there is no pain.