The macula is the central part of the retina in the eye. It is the only part of the retina that is capable of sharp, detailed vision for tasks such as reading, driving, and watching TV.
A macular hole is a disruption of the center of the macula. The interior of the eye is filled with a jelly-like substance called vitreous. As humans age, this jelly begins to shrink and travel towards the front of the eye. Deterioration of this jelly causes it to pull on the macula. In most cases, the vitreous separates without any negative side effects.
However, in some cases where the vitreous is firmly attached to the central area of the retina, this pulling away may form a small hole, known as a macular hole.
According to the Gass Classification System, macular holes can be classified into four stages:
Gass Modified Classification System
- Stage 1a- Central yellow spot and loss of foveal depression, vitreous attached over the fovea
- Stage 1b- Yellow ring with bridging interface, loss of foveal depression, vitreous attached over the fovea
- Stage 2- Retinal defect seen within yellow ring, may be round, crescent shaped, eccentric oval, or horseshoe in appearance. There may or may not be a prefoveal opacity (operculum)
- Stage 3- Central round full thickness retinal defect ³ 400 microns, rim of elevated retina. The premacular vitreous is still attached and no Weiss ring present. (vitreous still attached to nerve head) There may or may not be a prefoveal opacity (operculum)
- Stage 4- Central round full thickness retinal defect ³ 400 microns, rim of elevated retina. The premacular vitreous is detached and a Weiss ring is present. (vitreous detached from nerve head) There may or may not be a prefoveal opacity (operculum)
Symptoms of Macular Hole
It may rarely be an incidental finding. Symptoms appear gradually over days/weeks:
- Distorted vision as well as visual loss.
- Visual acuity (VA) will depend on the site of the hole, ie small eccentric holes may have little effect on acuity.
- Holes that are not full thickness also have less effect on acuity.
- Look for a tiny well-defined 'punched out' area of the macula which can be hard to detect. There may be yellow-white deposits at the base with a grey margin around it representing oedema.
- Slit lamp examination will show 'a round excavation with well-defined borders' interrupting the beam of the slit lamp.
- Most patients also have a semi-translucent tissue over the hole, which may be surrounded by a grey halo caused by detachment of the retina.
Macular holes usually occur in middle aged and older people. They are more common in women than men. People who are very nearsighted, or those who have had blunt injuries to their eyes, may also develop a macular hole. If you fall into the risk group and are experiencing symptoms mentioned heure, see your optometrist immediately.
Image Courtesy: Getty
Read more articles on Macular Hole.