Haziness, Flashing Lights, and Moving Spots
Posted by recep on April 19th, 2009Decreased visual perception due to opacities in the ocular media are most often attributed to vitreous floaters or to Moore’s lightning streaks. The vitreous humor is a gelatinous-like material that fills the back of the eye between the posterior surface of the lens and the anterior surface of the retina. The vitreous is normally clear, but with age, discrete opacities or structural changes leading to a general haziness may develop. With an ophthalmoscope, an examiner may be able to distinguish between lens opacities (best seen with a + 10 lens) and vitreous opacities (best seen with a +2 lens). Although these changes are not serious, they may upset the patient, and an explanation and reassurance are necessary.
The vitreous is firmly attached to the most anterior peripheral portion of the retina and posteriorly at the optic nerve. With age, the vitreous undergoes liquefaction, and as a result, eye movements produce intermittent tension at the vitreous attachment to the retina. This tugging stimulates the peripheral retina mechanically, causing vertically oriented flashing lights, almost always in the far temporal visual field. Unlike the aura in migraine, these flashing lights occur in only one eye at a time. If they are not accompanied by decreased vision or other changes in visual function, they usually need no further evaluation. However, if they persist and the feeling of a veil over the eye or a decrease in the visual field occurs, the patient should be referred immediately for an ophthalmologic examination to exclude retinal detachment.
In nearsighted (myopic) patients and in many others in their late 50s and early 60s, opacities appear as lines, spots, webs, and clusters of dots moving slowly across the field of vision. Usually, they move more rapidly with eye movements and become stationary when the eye is not moving. These opacities represent bits of vitreous that have coalesced or vitreous that has broken off from its attachment to the peripheral or central portion of the retina and now floats freely in the vitreous cavity (floaters). Floaters may also occur in uveitis. This symptom is annoying but usually has no clinical importance. If, after appropriate examination, the patient is reassured and encouraged to ignore the floaters, they gradually become less noticeable. However, a shower of opacities, often accompanied by flashing lights in the peripheral visual field, requires a referral to rule out retinal detachment.
Tags: and Moving Spots, Flashing Lights, Haziness
